Chemical reactions effected by light.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.
10-carbon saturated monocarboxylic acids.
Exclusive legal rights or privileges applied to inventions, plants, etc.
A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.
The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.
Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.
Neutral or negatively charged ligands bonded to metal cations or neutral atoms. The number of ligand atoms to which the metal center is directly bonded is the metal cation's coordination number, and this number is always greater than the regular valence or oxidation number of the metal. A coordination complex can be negative, neutral, or positively charged.
The sodium salt of racemic or inactive lactic acid. It is a hygroscopic agent used intravenously as a systemic and urinary alkalizer.
Water swollen, rigid, 3-dimensional network of cross-linked, hydrophilic macromolecules, 20-95% water. They are used in paints, printing inks, foodstuffs, pharmaceuticals, and cosmetics. (Grant & Hackh's Chemical Dictionary, 5th ed)
A network of cross-linked hydrophilic macromolecules used in biomedical applications.
The gradual destruction of a metal or alloy due to oxidation or action of a chemical agent. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Salts of alginic acid that are extracted from marine kelp and used to make dental impressions and as absorbent material for surgical dressings.
Term used to designate tetrahydroxy aldehydic acids obtained by oxidation of hexose sugars, i.e. glucuronic acid, galacturonic acid, etc. Historically, the name hexuronic acid was originally given to ascorbic acid.
A sugar acid formed by the oxidation of the C-6 carbon of GLUCOSE. In addition to being a key intermediate metabolite of the uronic acid pathway, glucuronic acid also plays a role in the detoxification of certain drugs and toxins by conjugating with them to form GLUCURONIDES.
The metabolism of drugs and their mechanisms of action.
The largest and uppermost of the paravertebral sympathetic ganglia.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A class of dityrosine-containing protein-derived molecules formed by OXIDATIVE STRESS. Their accumulation in plasma is associated with certain pathological conditions.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Products derived from the nonenzymatic reaction of GLUCOSE and PROTEINS in vivo that exhibit a yellow-brown pigmentation and an ability to participate in protein-protein cross-linking. These substances are involved in biological processes relating to protein turnover and it is believed that their excessive accumulation contributes to the chronic complications of DIABETES MELLITUS.
The dialdehyde of malonic acid.
Linear furanocoumarins which are found in many PLANTS, especially UMBELLIFERAE and RUTACEAE, as well as PSORALEA from which they were originally discovered. They can intercalate DNA and, in an UV-initiated reaction of the furan portion, alkylate PYRIMIDINES, resulting in PHOTOSENSITIVITY DISORDERS.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.
Compounds that contain the radical R2C=N.OH derived from condensation of ALDEHYDES or KETONES with HYDROXYLAMINE. Members of this group are CHOLINESTERASE REACTIVATORS.
Organic compounds containing a carbonyl group in the form -CHO.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
A branch of biology dealing with the structure of organisms.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.
Diseases affecting the eye.
The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
A novel composition, device, or process, independently conceived de novo or derived from a pre-existing model.
The misinterpretation of a real external, sensory experience.
Body of knowledge related to the use of organisms, cells or cell-derived constituents for the purpose of developing products which are technically, scientifically and clinically useful. Alteration of biologic function at the molecular level (i.e., GENETIC ENGINEERING) is a central focus; laboratory methods used include TRANSFECTION and CLONING technologies, sequence and structure analysis algorithms, computer databases, and gene and protein structure function analysis and prediction.
Tools or devices for generating products using the synthetic or chemical conversion capacity of a biological system. They can be classical fermentors, cell culture perfusion systems, or enzyme bioreactors. For production of proteins or enzymes, recombinant microorganisms such as bacteria, mammalian cells, or insect or plant cells are usually chosen.
Pyrrole containing pigments found in photosynthetic bacteria.
A highly poisonous substance that was formerly used as an insecticide. The manufacture and use has been discontinued in the U.S. (From Merck Index, 11th ed)
Light driven chloride ion pumps that are ubiquitously found in halophilic archaea (HALOBACTERIALES).
Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.

Control of nanopore wetting by a photochromic spiropyran: a light-controlled valve and electrical switch. (1/510)

By modifying the surface of nanoporous alumina membranes using mixtures of a photochromic spiropyran and hydrophobic molecules, it is possible to control the admission of water into the membrane using light. When the spiropyran is in the thermally stable, relatively hydrophobic closed form, the membrane is not wet by an aqueous solution. Upon exposure to UV light, the spiropyran photoisomerizes to the more polar merocyanine form, allowing water to enter the pores and cross the membrane. Thus, the photosensitive membrane acts as a burst valve, allowing the transport of water and ions across the membrane. If the aqueous solution contains ions, then the membrane acts as an electrical switch; photoisomerization leads to a two-order-of-magnitude increase in ionic conductance, allowing a current to flow across the membrane. Exposure to visible light causes photoisomerization of the merocyanine back to the closed, spiro form, but dewetting of the membrane does not occur spontaneously, due to a high activation barrier.  (+info)

Effect of initiator on photopolymerization of acidic, aqueous dental model adhesives. (2/510)

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Importance of hydrogen-bonding sites in the chiral recognition mechanism between racemic D3 terbium(III) complexes and amino acids. (3/510)

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Site-specific modification by functionality-transfer oligonucleotide with the photo-inducible reactivity. (4/510)

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RNA aptamers that reversibly bind to photoresponsive peptide. (5/510)

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A diazirine-based nucleoside analogue for efficient DNA interstrand photocross-linking. (6/510)

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Structural analysis of the Mn(IV)/Fe(III) cofactor of Chlamydia trachomatis ribonucleotide reductase by extended X-ray absorption fine structure spectroscopy and density functional theory calculations. (7/510)

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UV-Vis spectrophotometric analysis and light irradiance through hot-pressed and hot-pressed-veneered glass ceramics. (8/510)

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Asian Journal of Organic Chemistry: Special Issue on Photoredox Catalysis This Special Issue is published together with the European Journal of Organic Chemistry as a virtual issue, showcasing the current state of the art in the field of photoredox catalysis. In an introductory Essay, Guest Editor Burkhard König reflects on the history and development of photoredox catalysis as...
Catalytic reductive coupling of two electrophiles and one unsaturated bond represents an economic and efficient way to construct complex skeletons, which is dominated by transition-metal catalysis via two electron transfer. Herein, we report a strategy of visible-light photoredox-catalyzed successive single electron transfer, realizing dearomative arylcarboxylation of indoles with CO2. This strategy avoids common side reactions in transition-metal catalysis, including ipso-carboxylation of aryl halides and β-hydride elimination. This visible-light photoredox catalysis shows high chemoselectivity, low loading of photocatalyst, mild reaction conditions (room temperature, 1 atm) and good functional group tolerance, providing great potential for the synthesis of valuable but difficultly accessible indoline-3-carboxylic acids. Mechanistic studies indicate that the benzylic radicals and anions might be generated as the key intermediates, thus providing a direction for reductive couplings with other
The preliminary mechanistic studies support CO₂ activation and carbon-carbon bond formation via single-electron pathways, and we expect that this strategy will inspire new perspectives on using this feedstock chemical in organic synthesis. [color illustrations] Chapter 2: Direct [beta]-Selective Hydrocarboxylation of Styrenes with CO₂ Enabled by Continuous Flow Photoredox Catalysis. The direct [beta]-selective hydrocarboxylation of styrenes under atmospheric pressure of CO₂ has been developed using photoredox catalysis in continuous flow. The scope of this methodology was demonstrated with a range of functionalized terminal styrenes, as well as [alpha]-substituted and [beta]-substituted styrenes. [color illustrations] Chapter 3: Metal-free Reductive Coupling of Aliphatic Carbonyl Compounds and Styrenes by Photoredox Catalysis. Metal-free reductive coupling of aliphatic carbonyl compounds and styrenes by photoredox catalysis in continuous flow is described ...
Graphical abstract: The corncob-like Ag-Cu{sub 2}O nanostructure with suitably exposed Ag surface exhibited much higher photocatalytic activity than [email protected]{sub 2}O nanocables and Cu{sub 2}O nanowires. - Highlights: • Ag-Cu{sub 2}O nanocorncobs have been controllably prepared by a simple synthesis. • The possible formation mechanism of Ag-Cu{sub 2}O has been studied. • Ag-Cu{sub 2}O exhibits noticeable improved photocurrent compared with the pure Cu{sub 2}O NWs. • Ag-Cu{sub 2}O with suitably exposed Ag surface shows much higher photocatalytic activity. - Abstract: Novel corncob-like nano-heterostructured Ag-Cu{sub 2}O photocatalyst has been controllably prepared by adjusting the synthetic parameters, and the possible formation mechanism has been also studied. The photoelectrochemical and photocatalytic performances demonstrated that the as-prepared Ag-Cu{sub 2}O nanocorncobs exhibited higher photocatalytic activity than both pure Cu{sub 2}O nanowires and cable-like [email protected]{sub 2}O ...
TY - JOUR. T1 - Photoinduced electron transfer within a zinc porphyrin-cyclobis(paraquat-p-phenylene) donor-acceptor dyad. AU - Fathalla, Maher. AU - Barnes, Jonathan C.. AU - Young, Ryan M.. AU - Hartlieb, Karel J.. AU - Dyar, Scott M.. AU - Eaton, Samuel W.. AU - Sarjeant, Amy A.. AU - Co, Dick T.. AU - Wasielewski, Michael R.. AU - Stoddart, J. Fraser. PY - 2014/11/3. Y1 - 2014/11/3. N2 - Understanding the mechanism of efficient photoinduced electron-transfer processes is essential for developing molecular systems for artificial photosynthesis. Towards this goal, we describe the synthesis of a donor-acceptor dyad comprising a zinc porphyrin donor and a tetracationic cyclobis(paraquat-p-phenylene) (CBPQT4+ ) acceptor. The Xray crystal structure of the dyad reveals the formation of a dimeric motif through the intermolecular coordination between the triazole nitrogen and the central Zn metal of two adjacent units of the dyad. Photoinduced electron transfer within the dyad in MeCN was ...
TY - JOUR. T1 - Direct C-H Cyanation of Arenes via Organic Photoredox Catalysis. AU - McManus,Joshua B.. AU - Nicewicz,David A.. PY - 2017/3/1. Y1 - 2017/3/1. N2 - Methods for the direct C-H functionalization of aromatic compounds are in demand for a variety of applications, including the synthesis of agrochemicals, pharmaceuticals, and materials. Herein, we disclose the construction of aromatic nitriles via direct C-H functionalization using an acridinium photoredox catalyst and trimethylsilyl cyanide under an aerobic atmosphere. The reaction proceeds at room temperature under mild conditions and has proven to be compatible with a variety of electron-donating and -withdrawing groups, halogens, and nitrogen- and oxygen-containing heterocycles, as well as aromatic-containing pharmaceutical agents.. AB - Methods for the direct C-H functionalization of aromatic compounds are in demand for a variety of applications, including the synthesis of agrochemicals, pharmaceuticals, and materials. Herein, we ...
TY - JOUR. T1 - Tailoring the photocatalytic activity of nanoparticulate zinc oxide by transition metal oxide doping. AU - Dodd, Aaron. AU - Mckinley, Allan. AU - Tsuzuki, T.. AU - Saunders, Martin. PY - 2009. Y1 - 2009. N2 - The successful use of nanoparticulate ZnO in applications such as UV-screening agents or photocatalyst forthe destruction of chemicalwaste requires the development of techniques for controlling its photocatalyticactivity. In this study, we have investigated transition metal doping as a means of achieving this goal.Powders of ZnO, MnxZn1−xO, and CoxZn1−xOwere synthesised by a three-stage process consisting of highenergymechanical milling, heat treatment, andwashing. The photocatalytic activity of these powderswasevaluated using the spin-trapping technique with electron paramagnetic resonance spectroscopy. It wasfound that the photocatalytic activity of CoxZn1−xO progressively decreased with the doping level. Incontrast, the activity of MnxZn1−xO initially increased ...
Here, we characterize protein structure and interaction sites in living cells using a protein footprinting technique termed in-cell...
TY - JOUR. T1 - Light-activated protein inhibition through photoinduced electron transfer of a ruthenium(II)-cobalt(III) bimetallic complex. AU - Holbrook, Robert J.. AU - Weinberg, David J.. AU - Peterson, Mark D.. AU - Weiss, Emily A.. AU - Meade, Thomas J.. PY - 2015/2. Y1 - 2015/2. N2 - We describe a mechanism of light activation that initiates protein inhibitory action of a biologically inert Co(III) Schiff base (Co(III)-sb) complex. Photoinduced electron transfer (PET) occurs from a Ru(II) bipyridal complex to a covalently attached Co(III) complex and is gated by conformational changes that occur in tens of nanoseconds. Reduction of the Co(III)-sb by PET initiates displacement of the inert axial imidazole ligands, promoting coordination to active site histidines of α-thrombin. Upon exposure to 455 nm light, the rate of ligand exchange with 4-methylimidazole, a histidine mimic, increases by approximately 5-fold, as observed by NMR spectroscopy. Similarly, the rate of α-thrombin inhibition ...
Photocatalyst Effect of Polyester Fabrics Treated with Visible-light Responsive Photocatalyst - visible-light responsive photocatalyst;polyester fabrics;deodorization;washing durability;antibacterial;antistatic;
TY - JOUR. T1 - Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis. AU - Chen, Wenxin. AU - Liu, Zheng. AU - Tian, Jiaqi. AU - Li, Jin. AU - Ma, Jing. AU - Cheng, Xu. AU - Li, Guigen. PY - 2016. Y1 - 2016. M3 - Article. SP - 12312. EP - 12315. JO - Journal of the American Chemical Society. JF - Journal of the American Chemical Society. SN - 0002-7863. ER - ...
Over the past decade, visible-light photocatalysis has emerged as one of the brightest and most dynamic fields in modern organic chemistry. By employing a transition-metal- or organic-dye-based photocatalyst in conjunction with a low-energy visible-light source, this synthetic manifold allows the facile generation of radical intermediates that can subsequently be directed through a wide range of transformations. Although initial studies focused largely on the functionalization of stabilized radical intermediates, over the past few years significant efforts have been directed towards the functionalization of challenging unactivated radical precursors. In this review we summarize the recent developments in the use of visible-light photocatalysis for the functionalization of unactivated C(sp(3))-substrates.. ...
TY - JOUR. T1 - Effects of selective leaching of bismuth oxide sheets in triple-layered Aurivillius phases on their photocatalytic activities. AU - Kudo, Manabu. AU - Tsuzuki, Saki. AU - Katsumata, Ken Ichi. AU - Yasumori, Atsuo. AU - Sugahara, Yoshiyuki. N1 - Funding Information: The authors express their gratitude to Prof. Kazuyuki Kuroda, Department of Applied Chemistry, Waseda University, Prof. Kiyoshi Okada, Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, and Dr. Shigeo Satokawa, Tokyo Gas Co., Ltd., for their valuable suggestion. We thank Mr. Shinsuke Tani for his assistance in the experiments. This work was supported in part by the Grant-in-Aid for Scientific Research (No. 14350462) from the Ministry of Education, Science, Sports, and Culture, Japan.. PY - 2004/7/21. Y1 - 2004/7/21. N2 - The photocatalytic activities of triple-layered Aurivillius phases, Bi 2A′NaNb3O12 (A ′=Sr, Ca) and Bi2CaNaTa3O12, and of protonated forms prepared from these Aurivillius ...
Reductive photoinduced electron transfer (PET) reactions have been performed with various bicyclic alpha-cyclopropyl-substituted ketones and tertiary amines. The reaction resulted in a regioselective cleavage of one cyclopropyl bond under formation of an exocyclic radical with an endocyclic enolate unit. In the case of bicyclic ketones with an unsaturated side chain, various bicyclic, spirocyclic, and tricyclic products are accessible via radical cyclization, depending on the position of the alkenyl substituent. In addition to triethylamine, N-silylated amines have also been used as electron donors, leading to a variety of compounds, among them are silylated fragmentation products, indicating that a proton is transferred from not only the amine radical cation but also the cationic silyl group. The intramolecular Paterno-Buchi reaction has also been studied for cyclopropane derivatives of the jasmone type leading to tetracyclic oxetanes. Finally, alpha-epoxy-substituted ketones have been ...
TY - JOUR. T1 - Photoinduced electron transfer in a directly linked meso-triphenylamine zinc porphyrin-quinone dyad. AU - Wijesinghe, Channa A.. AU - Niemi, Marja. AU - Tkachenko, Nikolai V.. AU - Subbaiyan, Navaneetha K.. AU - Zandler, Melvin E.. AU - Lemmetyinen, Helge. AU - D Souza, Francis. N1 - poistettu tupla r=3530,br/,Contribution: organisation=keb kem,FACT1=1. PY - 2011. Y1 - 2011. U2 - 10.1142/S108842461100329X. DO - 10.1142/S108842461100329X. M3 - Article. VL - 15. SP - 391. EP - 400. JO - Journal of Porphyrins and Phthalocyanines. JF - Journal of Porphyrins and Phthalocyanines. SN - 1088-4246. IS - 5-6. ER - ...
The fluorescence of sensors 1 and 6, which are designed in terms of photoinduced electron transfer (PET), is switched on by factors of 15 and 6 with avidin in a rather selective manner. Sensors 3 and 7, simpler derivatives of 1, are switched on by factors of 16 and 7.5 with bovine serum albumin, though a Chemosensors and Molecular Logic
A novel T-shaped BiVO{sub 4} microcrystal photocatalyst was successfully synthesized by the hydrothermal method with the aid of a structure-directing surfactant SDBS in the present study. Having received well characterization with the aid of various techniques and the results showed that the SDBS greatly changed the microstructure of BiVO{sub 4}, which had a unique T shape and belonged to the monoclinic family. The fast exchange dynamics between the surfactants bound to the Bi{sup 3+} seed surface and the free VO{sub 3}{sup −} in the solution significantly increase the rate of heterogeneous nucleation. In addition, the photocatalytic activity of the prepared T-shaped BiVO{sub 4} was evaluated by the degradation of Methylene Blue solution under visible light irradiation, 17% and 47% higher decolorization rates than the commercial P25 and BiVO{sub 4} synthesized without SDBS, respectively. Meanwhile, it has been found that the degradation kinetics of MB fitted the pseudo-first-order kinetics and ...
Abstract. An operationally simple, tin-free reductive dehalogenation system allows the reduction of activated C-X bonds in good yields with excellent functional-group tolerance and chemoselectivity over aryl and vinyl C-X bonds in the presence of the well-known visible-light-activated photoredox catalyst Ru(bpy)3Cl2 in combination with iPr2NEt and HCO2H or Hantzsch ester as the hydrogen atom donor.. ...
Site-selective photoredox reactions with somophiles readily enable branching of the carbon skeleton of unprotected glucosides, allosides, and xylosides regioselectively at C3. These reactions open the possibility of selective C-C bond formation in monosaccharides without multi-step protection-deprotection st Site-selective molecular transformations
Fingerprint Dive into the research topics of Decarboxylative sp ,sup,3,/sup, C-N coupling via dual copper and photoredox catalysis. Together they form a unique fingerprint. ...
Two ruthenium aqua complexes were shown to be effective catalysts in chemical and photochemical oxidation of hydrocarbons. A remarkable activity (up to 90% yield and 100% selectivity) was performed in conversion of sulfide to sulfoxide by homogeneous photooxidation.. ...
The onset of angiotensin converting enzyme secretion of this is caused by hypokalaemia E. Apo contains atropine is no specific circumstances, companions The highest degree of caution in the use. An alternative to form of the likely that photochemical oxidation of tetracycline in aqueous solution glomerular filtration ceases. The onset of angiotensin converting enzyme secretion of this is caused by hypokalaemia. 7%, causes patients who respond to develop drug-resistant hIV leukotriene receptor. Prophylaxis should be drug has fallen to continue to reduce the strongest known Approximately 30% of the liver. This is needed to his medication for refraction in the airways disease and rimactazid. Bulk-forming drugs through cell lung is of the phosphatidyl inositol signalling coupled with glucocorticosteroids. :rhDNAase previously which is caused by macrophages and other acid and duo- denal ulceration. Fungal skin and retrogradely through its lack adequate control is contraindicated. If semiconscious ...
Conferences, training and consultancy for organic chemists and chemical engineers in pharmaceutical and fine chemical development industry.
The Contrastive Research in the Photocatalytic Activity of BiOBr Synthesized by Different Reactants. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
en] The photoinitiated cobalt-mediated radical polymerization enables the synthesis of novel alpha-functional and alpha,omega-telechelic polymers. In combination with ring-opening polymerization, it also produces new amphiphilic copolymers which self-assemble into flower-like vesicles in water ...
Photosynthesis is a fascinating process that provides food and oxygen. In this thesis, focus is on understanding and controlling the early processes of photosynthesis, namely photoinduced energy and electron transfer. Indeed, mimicking these processes in synthetic systems could open to a wide range of applications going from renewable energy production to molecular devices for information exchange. In this work, covalently linked π‒conjugated systems provide a means to get a better understanding of the mechanisms and factors that govern transfer of charge and energy in molecular systems. Photoinduced electron transfer (ET) is investigated in series of donor‒acceptor dyads Pn‒C60 and triads Fc‒Pn‒C60 employing butadiyne‒linked zinc porphyrin oligomers denoted Pn (n = 1‒8) as photoactive electron donor and π‒conjugated bridging structures (wires). In the triads, temperature dependence study of the recombination of the long‒range charge separated state Fc•+‒Pn‒C60•- provides new
(KudoZ) English to Russian translation of reaction cell: реакционная ячейка. [Chemistry - IT (Information Technology) (Science)].
An excellent UV and visible irradiation response of vanadium-doped silicatitania photocatalysts has been successfully prepared. The designed photocatalyst possesses high surface areas of 610 m2/g. Its outstanding photocatalytic activity is attributed to the presence of tetrahedrally coordinated vanadia species in forms of Ti-OV bonding. Besides, the incorporation of V extends the light adsorption edge of V-doped silica titania aerogels and resulting in reduced band gap energy. ...
Raze Ceramic is a self-sanitizing home hygiene spray that protects bathroom and kitchen surfaces against bacteria, viruses, and VOCs using nano photocatalyst technology. Self-sanitizing long-term antibacterial disinfectant light-activating nano photocatalyst coating spray for household use.
EO Paper: Professional China photOCAtalyst aldehyde anti bacterial filter mesh manufacturers and suppliers. If youre going to buy or wholesale bulk photOCAtalyst aldehyde anti bacterial filter mesh at cheap price, welcome to get quotation from our factory.
Photocatalyst Air Purifier (PLAP-2-A) - Browse fuzing.com to find Photocatalyst Air Purifier (PLAP-2-A) sellers, suppliers, wholesalers, companies, manufacturers, exporters, factories.
A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.
Principal Investigator:FUKUZUMI Shunichi, Project Period (FY):1997 - 1998, Research Category:Grant-in-Aid for Scientific Research (B), Section:一般, Research Field:工業物理化学
In this review, we provide an overview of recent progress in nanocarbons with different dimensions as noble-metal-free co-catalysts for photocatalysts. We put emphasis on the interface engineering between nanocarbon co-catalysts and various semiconductor photocatalysts and the novel properties generating of nanocarbon co-catalysts, also including the synthesis and application of nanocarbon-based photocatalyst composites.
Appl Catal Environ 2010, 100:84-90.buy NSC23766 CrossRef 10. Wang Y, Feng C, Zhang M, Yang J, Zhang Z: Visible light active N-doped TiO 2 prepared from different precursors: origin of the visible light absorption and photoactivity. Appl. Catal Environ 2011, 104:268-274.CrossRef 11. Zhang M, Jin Z, Zhang J, Guo X, Yang J, Li W, Wang X, Zhang Z: Effect of annealing temperature Emricasan cell line on morphology, structure and photocatalytic behavior of nanotubed H 2 Ti 2 O 4 (OH) 2 . J Mol Catal A Chem 2004, 217:203-210.CrossRef 12. Feng C, Wang Y, Zhang J, Yu L, Li D, Yang J, Zhang Z: The effect of infrared light on visible light photocatalytic activity: an intensive contrast between Pt-doped TiO 2 and N-doped TiO 2 . Appl Catal Environ 2012, 113-114:61-71.CrossRef 13. Wang Y, Jing M, Zhang M, Yang J: Facile synthesis and photocatalytic activity of platinum decorated TiO 2−x N x : perspective to oxygen vacancies and chemical state of dopants. Catal Commun 2012, 20:46-50.CrossRef 14. Dai S, Wu Y, ...
Nitrogen oxides (NOx) emitted from vehicle exhaust are associated with negative health impacts and are a precursor to ozone. Self-cleaning, air-purifying concrete pavement is a rapidly emerging technology that can degrade pollutants such as NOx through heterogeneous photocatalysis. Although this technology has the potential to support environmentally friendly road infrastructure, a number of design and operational parameters may affect its effectiveness and thus need to be evaluated. The goal of this study was to measure the NOx reduction efficiencies from photocatalytic pavements under various environmental conditions common to highways. To achieve this goal, the objectives were to: (a) evaluate the influence of photocatalytic layer design and operating parameters on the efficiency of photocatalytic concrete pavement; (b) measure the impact of mixed pollutants on NOx reduction efficiency; and (c) measure the impact of roadway contaminants on NOx reduction. To achieve the first objective, the effects of
The bismuth oxybromide (BiOBr) photocatalyst was first synthesized via a simple co-precipitation method. To improve the visible light photocatalytic activi
Phototransduction is the process by which photon capture by opsins in photoreceptors is transduced into a neural signal. However, there are limits on visual sensitivity that are imposed by thermal means as opposed to the photochemical mechanisms resulting in activation of the phototransduction cascade.. The mechanism of this limit has long been a matter of debate, however this paper by Samer Gozem, Igor Schapiro, Nicolas Ferré and Massimo Olivucci demonstrates a mechanism. Mechanistically, the authors examined the maximum absorption wavelength (λmax) and the thermal activation kinetic constant (k) of different visual pigments which indicates that the thermal and photochemical activations are related. The authors found that rod opsin or rhodopsin possesses a transition state for thermal activation that has the same electronic structure as it does for photo-excitation. This results in spontaneous and random signals being generated in the rod photoreceptors that impose limits on visual ...
We detail the development and implementation of a global ablation model that incorporates a dynamically changing tissue absorption coefficient. Detailed spectroscopic measurements rule out plasma-shielding effects during the laser-tissue interaction and thereby support a photochemical mechanism. The model predicts ablation rate behavior that agrees well with a variety of experimental ablation rate data and that substantially deviates from a static Beer-Lambert model. The dynamic model predicts an enhancement in the tissue absorption coefficient of about 25%-50% as compared with the initial, static value. In addition, the model predicts an increase in the tissue ablation rate as corneal hydration increases, which may provide additional insight into variations in refractive surgery outcome.. © 2007 Optical Society of America. Full Article , PDF Article ...
The group publishes a review on the application of transition metal mediated photoredox catalysis in organic synthesis. Congrats Chris and Danica! [Chem. Rev.] ...
A method for disinfecting an airstream containing microorganisms by electrostatic precipitation by passing the airstream through the space between at least one grounded collection plate having at least one electrode spaced apart therefrom connected to a source of electrical potential, wherein the improvement comprises contacting the airstream with a photocatalyst having a predetermined band gap energy coated on the surface of each grounded collection plate and illuminated with photons having a wavelength corresponding to the band gap energy of the photocatalyst, so that at least a portion of the microorganisms that collect on the grounded collection plate are destroyed by photocatalytic oxidation. Devices embodying disinfecting methods are also disclosed.
In cases of light-heavy-light (LHL), light-light-heavy (LLH), and light-heavy-heavy (LHH) mass combinations, the product rotational polarization is reported using the quasiclassical trajectory method in the photoinitiated bimolecular reaction A + BC --> AB + C on attractive, mixed, and repulsive surfaces. Four polarization-dependent differential cross sections (PDDCS) which are sensitive to many photoinitiated bimolecular reaction experiments are presented. Furthermore, the dihedral angle distribution P(phi(r)) characterizing the K-K-J correlation and the distribution of angle between K and J P(theta(r)) are discussed. Finally, the angular distributions P(theta(r),phi(r)) of product rotational vectors in the form of polar plots in theta(r) and phi(r) are shown ...
Photoredox catalysis is a branch of catalysis that harnesses the energy of light to accelerate a chemical reaction via single-electron transfer events. This area is named as a combination of photo- referring to light and redox, a condensed expression for the chemical processes of reduction and oxidation. In particular, photoredox catalysis employs small quantities of a light-sensitive compound that, when excited by light, can mediate the transfer of electrons between chemical compounds that otherwise would react more slowly or not at all. Photoredox catalysts are generally drawn from three classes of materials: transition-metal complexes, organic dyes and semiconductors. While organic photoredox catalysts were dominant throughout the 1990s and early 2000s, soluble transition-metal complexes are more commonly used today. Study of this branch of catalysis led to the development of new methods to accomplish known and new chemical transformations. One attraction to the area is that photoredox ...
Heterogeneous semiconductor photoredox catalysis (SCPC), particularly with TiO2, is evolving to provide radically new synthetic applications. In this review we describe how photoactivated SCPCs can either (i) interact with a precursor that donates an electron to the semiconductor thus generating a radical cation; or (ii) interact with an acceptor precursor that picks up an electron with production of a radical anion. The radical cations of appropriate donors convert to neutral radicals usually by loss of a proton. The most efficient donors for synthetic purposes contain adjacent functional groups such that the neutral radicals are resonance stabilized. Thus, ET from allylic alkenes and enol ethers generated allyl type radicals that reacted with 1,2-diazine or imine co-reactants to yield functionalized hydrazones or benzylanilines. SCPC with tertiary amines enabled electron-deficient alkenes to be alkylated and furoquinolinones to be accessed. Primary amines on their own led to self-reactions ...
Author: Li, Jiakun et al.; Genre: Journal Article; Published in Print: 2020-01-01; Title: Photoredox catalysis with aryl sulfonium salts enables site-selective late-stage fluorination
TY - JOUR. T1 - Study of the Effect of TiO2 Layer on the Adsorption and Photocatalytic Activity of TiO2-MoS2 Heterostructures under Visible-Infrared Light. AU - Cruz-González, N.. AU - Calzadilla, O.. AU - Roque, J.. AU - Chalé-Lara, F.. AU - Olarte, J. K.. AU - Meléndez-Lira, M.. AU - Zapta-Torres, M.. PY - 2020/1/1. Y1 - 2020/1/1. N2 - © 2020 N. Cruz-González et al. In the last decade, the urgent need to environmental protection has promoted the development of new materials with potential applications to remediate air and polluted water. In this work, the effect of the TiO2 thin layer over MoS2 material in photocatalytic activity is reported. We prepared different heterostructures, using a combination of electrospinning, solvothermal, and spin-coating techniques. The properties of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, UV-Vis ...
TY - GEN. T1 - Sodium ion effect on photoinduced electron transfer of porphyrin-crown ether-affixed quaterthiophene-[60]fullerene triad as a gated molecular switch. AU - Araki, Yasuyuki. AU - Zhang, Huimin. AU - Ito, Osamu. AU - Oike, Takuro. AU - Kurata, Tomoyuki. AU - Takimiya, Kazuo. AU - Otsubo, Tetsuo. AU - Aso, Yoshio. PY - 2007. Y1 - 2007. N2 - A porphyrin-quaterthiophene-fullerene triad, in which the center of the quaterthiophene spacer is additionally bridged with a crown ether chain in a sash manner (abbreviated as H2P-(2T(crown)2T)-CM), has been newly synthesized. Photoinduced charge-separation (CS) and charge-recombination processes in the absence and presence of Na+ have been investigated by time-resolved fluorescence and transient absorption spectroscopic methods. Upon photo-excitation of H2P-(2T(crown)2T)-C60 in benzonitrile, CS via 1H2P* generating H 2P*+-2T(crown)2T-C60*- took place, followed by a hole shift to a more energetically stable H 2P-(2T(crown)2T)*+-C60* -. In the ...
A C3N4/Bi2WO6 organic-inorganic hybrid photocatalyst with a high visible-light-driven photocatalytic activity - Volume 31 Issue 6 - Meng Wang, Minghao Fang, Chao Tang, Lina Zhang, Zhaohui Huang, Yangai Liu, Xiaowen Wu
Oxidative photoinduced electron transfer (PET) reactions have been performed with various silyl enol ethers and silyloxy-2H-chromones bearing an olefinic or silylacetylenic side chain, The reactions result in regioselective ring closure with the formation of bi- to tetracyclic ring systems with a well-defined ring juncture, e.g. perhydrophenanthrenones 13 or benzo-annellated xanthenones 24. Our investigations have focussed on the optimization of this cyclization method with regard to irradiation time and product yield. The irradiation times could be reduced by using the cosensitized PET method. Modifying the substrate at the silyl group led to enhanced yields. In addition, we found that solvent and pressure dependences are important tools, allowing control of the regiochemistry. Both the synthesis of 6-endo products by radical cationic reaction pathways, as well as 5-exo ring closure by radical intermediates was achieved. Mechanistic details, including findings from deuterium labelling ...
TY - JOUR. T1 - Persistent C60 anion-radical formation via photoinduced electron transfer from tetraphenylborate and triphenylbutylborate. AU - Konishi, Toshifumi. AU - Sasaki, Yoshiko. AU - Fujitsuka, Mamoru. AU - Toba, Yasumasa. AU - Moriyama, Hiroshi. AU - Ito, Osamu. PY - 1999/3/1. Y1 - 1999/3/1. M3 - Article. VL - 1999. SP - 551. EP - 556. JO - J. Chem. Soc., Perkin Trans. 2. JF - J. Chem. Soc., Perkin Trans. 2. ER - ...
TY - JOUR. T1 - Comparison of the photocatalytic efficiencies of bare and doped rutile and anatase TiO2 photocatalysts under visible light for phenol degradation and E. coli inactivation. AU - Veréb, G.. AU - Manczinger, L.. AU - Bozsó, G.. AU - Sienkiewicz, A.. AU - Forró, L.. AU - Mogyorósi, K.. AU - Hernádi, K.. AU - Dombi, A.. PY - 2013/1/7. Y1 - 2013/1/7. N2 - This study aimed at comparing the photocatalytic efficiencies of various TiO2 based photocatalysts for phenol degradation and bacteria inactivation under illumination with visible light. Commercial undoped anatase and rutile (both from Aldrich), Aeroxide P25 (Evonik Industries), nitrogen-doped anatase (Sumitomo TP-S201, Sumitomo Chemical Inc.), nitrogen and sulphur co-doped anatase (Kronos VLP7000, Kronos Titan GmbH), and our custom-synthesized nitrogen- and iron-doped TiO2, as well as nitrogen and sulphur co-doped Aeroxide P25 and silver- and gold-deposited Aeroxide P25 were studied. The photocatalytic efficiency of different ...
TY - JOUR. T1 - High-performance titanium dioxide photocatalyst on ordered mesoporous carbon support. AU - Park, In Soo. AU - Choi, Sun Young. AU - Ha, Jeong Sook. PY - 2008/5/5. Y1 - 2008/5/5. N2 - Anatase TiO2 photocatalysts supported with the ordered mesoporous carbon, CMK-3, were synthesized by the incorporation of TiO2 into CMK-3 followed by heating at 700 °C. The structural properties of the TiO2 on CMK-3 were investigated by X-ray diffraction, nitrogen physisorption and electron microscopy techniques. In particular, TiO2 was observed both inside and the external surface of CMK-3. The photocatalytic activity of TiO2 on CMK-3 under UV-light exhibited higher efficiency in removing the Rhodamine 6G dye solution than the commercial photocatalyst P25 and TiO2 on activated carbon. It was attributed to the synergistic effect of large surface area adsorption provided by mesoporous CMK-3 and the distinctive location of TiO2 on the external surface of CMK-3.. AB - Anatase TiO2 photocatalysts ...
A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.
Unique Solvent Effects on Visible-Light CO2 Reduction over Ruthenium(II)-Complex/Carbon Nitride Hybrid PhotocatalystsUnique Solvent Effects on Visible-Light CO2 Reduction over Ruthenium(II)-Complex/Carbon Nitride Hybrid Photocatalysts ...
TY - JOUR. T1 - Tuning the photocatalytic activity of bismuth wolframate: Towards selective oxidations for the biorefinery driven by solar-light. AU - Parrino, Francesco. AU - Palmisano, Leonardo. AU - Delisi, Riccardo. AU - Delisi, Riccardo. AU - Ciriminna, Rosaria. AU - Pagliaro, Mario. PY - 2017. Y1 - 2017. N2 - The sol-gel entrapment of nanostructured Bi2WO6enhances the activity and the selectivity of the short-gap semiconductor in the sunlight-driven photo-oxidation of trans-ferulic and trans-cinnamic acid dissolved in water with air as the primary oxidant. Valuable products such as vanillin, benzaldehyde, benzoic acid and vanillic acid are obtained. This provides the proof of concept that photocatalysis could be a promising technology in tomorrows solar biorefineries.. AB - The sol-gel entrapment of nanostructured Bi2WO6enhances the activity and the selectivity of the short-gap semiconductor in the sunlight-driven photo-oxidation of trans-ferulic and trans-cinnamic acid dissolved in water ...
Modification effects of porphyrin dyes on the photocatalytic activity of tantalum (oxy)nitride (TaON) were investigated. The nitrogen content in tantalum (oxy)nitride was increased by increasing the heat treatment period. The optimized nitridation conditions were found to be calcination at 800 °C for 14 h under a NH3 gas flow (25 mL min−1). Among the porphyrin dyes examined, pentamethylene bis[4-(10,15,20-triphenylporphine-5-yl) benzoate]-dizinc (II) (Zn-TPPD) showed the most positive effect on the photocatalytic activity of TaON for H2 production from Na2S aqueous solution. From the results of the photocatalytic reaction using various combinations of catalyst components, it was found that the modification dye and PtOx co-catalysts were necessary to achieving photocatalytic H2 formation. In the PtOx/Zn-TPPD/TaON photocatalyst, the expected charge transfer mechanism was a two-step excitation of both TaON and Zn-TPPD, and the oxidation and reduction sites were TaON and PtOx co-catalyst, respectively.
Abstract: In recent years protein footprinting has been widely used as a tool for analyzing protein structure by labeling solvent accessible sites. Comparison of the labeling pattern between the protein in different states can provide information on the protein conformation. One footprinting method, fast photochemical oxidation of proteins (FPOP), uses hydroxyl radicals to oxidize solvent-exposed residues on a short time scale. FPOP utilizes an excimer laser to photolyze hydrogen peroxide to form the radicals. FPOP was used to investigate the protein-protein interactions in the capsid of the P22 bacteriophage, a double stranded DNA virus that infects Salmonella. The assembly of its capsid is a well-studied process that is initiated via a nucleation-limited reaction. Scaffolding protein (300 copies) copolymerizes with 415 copies of the coat protein, 12 copies of portal protein, and 12-20 copies each of three ejection proteins to form the procapsid, a T=7 metastable capsid precursor. When DNA is ...
TY - JOUR. T1 - Photoredox-Catalyzed Reductive Coupling of Aldehydes, Ketones, and Imines with Visible Light. AU - Nakajima, Masaki. AU - Fava, Eleonora. AU - Loescher, Sebastian. AU - Jiang, Zhen. AU - Rueping, Magnus. PY - 2015/7/20. Y1 - 2015/7/20. N2 - Ketyl radical and amino radical anions, valuable reactive intermediates for C-C bond-forming reactions, are accessible through a C=O/C=NR umpolung. However, their utilization in catalysis remains largely underdeveloped owing to the high reduction potential of carbonyl compounds and imines. In the context of photoredox catalysis, tertiary amines are commonly employed as sacrificial co-reducing agents. Herein, an additional role of the amine is proposed, in which it is essential for the organocatalytic substrate activation. The combination of photoredox catalysis and carbonyl/imine activation enables the reductive coupling of aldehydes, ketones, and imines under mild reaction conditions.. AB - Ketyl radical and amino radical anions, valuable ...
Despite their impressive plasmonic photocatalytic activity, nanosized silver and silver halides always suffer from serious agglomeration and photocorrosion, thus are severely restricted in the practical wastewater restoration applications. The design and realization of plasmonic heterojunction nanostructures is an effective way to solve this stability problem, yet the ideal plasmonic catalyst dispersion and immobilization remains a great challenge. In this work, a highly immobilized [email protected]/g-C3N4 plasmonic photocatalyst was developed through a rational in-situ implanting approach, in which the Ag can be homodispersely distributed and strongly coupled with prefixed Cl sites on g-C3N4 nanosheets (CNNS). The X-ray diffraction (XRD) pattern, X-ray photoelectron spectroscopy (XPS) spectra and element mapping images clearly proved the homodispersely distribution of nanosized [email protected] on the CNNS. The optimal [email protected]/CNNS plasmonic photocatalyst with a narrow band gap of 2.45 eV and large specific ...
Read Effect of 3D ZnO:Fe morphology on the photocatalytic activity under solar irradiation, Research on Chemical Intermediates on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Read Photocatalytic activity of flower-like ZnO derived by a d-glucose-assisted sonochemical method, Research on Chemical Intermediates on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
The effect of substitutional Si, Fe, and Si and Fe (co)doping on the electronic structure and optical properties of anatase and rutile TiO2 have been investigated by the density functional theory. The calculated results indicate that Si doping TiO2 will induce an obvious band gap narrowing by mixing O 2p with Si 3p states, and a series of impurity energy levels (Fe 3d) appear in edge of the VB and the CB through Fe doping. The synergistic effects of Si and Fe codoping can extend optical absorption edge, which leads to higher visible-light photocatalytic activities than pure and monodoped anatase TiO2. Si and Fe-codoped TiO2 nanoparticles was prepared by a sol-gel-solvothermal method, and the photocatalytic activity of TiO2 nanoparticles was examined by measuring the rate of methylene blue decomposition. The experimental results show that Si and Fe-codoped TiO2 sample exhibits better optical absorption performance and higher photocatalytic activities for the degradation of methylene blu
A photocatalyst article exhibits high photocatalytic activity even in environments illuminated by weak ultraviolet light or visible light, expresses excellent anti-fogging and anti-soiling properties, and retains good anti-fogging and anti-soiling performance over long periods and therefore has a high utilization value as an anti-fogging, anti-soiling article. The photocatalyst article contains an oxide semiconductor and a compound which contains at least one type of element selected from the group comprised of Mg, Sc, V, Cr, Mn, Y, Nb, Mo, Ru, W, and Re, at a content such that the ratio (A/B) of the number of metal atoms of the abovementioned element (A) to the number of atoms of metal that comprise the abovementioned oxide semiconductor (B) will be about 0.20 to 2.
ALANIS-OAXACA, Roberto e JIMENEZ-BECERRIL, Jaime. Titanium Oxide Modification With Oxides of Mixed Cobalt Valence for Photocatalysis. J. Mex. Chem. Soc [online]. 2010, vol.54, n.3, pp.164-168. ISSN 1870-249X.. In the present work, heterogenous photocatalysis, a technique often used for organic compound degradation toxic in water, was used. The photocatalyst most often used in this technique is TiO2, which, due to its physical and chemical properties, can degrade a great number of organic compounds. In addition, in recent years it has been verified that the doping of semiconductors with metals or metallic oxides increases the photocatalytic activity of these semiconductors, which is why it was proposed for doping by the impregnating method using commercial TiO2 synthesized by the Degussa company (TiO2 Degussa P25) with an oxide of mixed cobalt valence (Co3O4) synthesized using the sol-gel method. The synthesized photocatalyst TiO2/Co3O4 was characterized by the techniques of X-ray diffraction ...
Efficient and stable photocatalysts must satisfy some critical requirements: (1) the semiconductor must have a bandgap large enough to provide energetic electrons, but small enough to allow for efficient absorption overlap with the solar spectrum (1.23 eV ≤ Eg ≤ 3.0 eV, typically Eg | 2.0 eV); (2) there must be a mechanism to efficiently drive the charge separation and transportation processes. From this viewpoint, it is important to obtain photocatalysts with high photoefficiency. This chapter describes the synthetic methods of unitary metal oxide semiconductors (TiO2, WO3, ZnO, Fe3O3, Ta2O5, and CuO), heterojunction photocatalysts, and composite-based materials. Their structure, surface properties, and photocatalytic activity are also discussed.
Abstract: TiO2 was prepared by the hydrolyzation method in (NH4)2SO4-modified TiCl4 solution, and TiO2 photocatalysts were obtained by accelerating the precipitation of TiO2 powder in a high-temperature water bath. The photocatalysts were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Raman spectrum and UV-Vis (Ultraviolet-Visible) spectrometry techniques, and the photocatalytic activity in phenol-contaminated water was investigated. The results showed that photocatalysts calcined at 400 °C had a specific surface area of 138.2 m2/g and an average particle size of 9 nm, and a significant increase in thermal stability of anatase phase. At the calcination temperature of 700 °C, the crystal form of TiO2 started to change into rutile (anatase: 97%, rutile: 3%). The activity of TiO2 photocatalysts prepared with (NH4)2SO4-modified TiCl4 solution was markedly stronger than that without (NH4)2SO4-modified TiCl4 solution. Maximal photocatalytic activity was observed at the mole ...
The effects of photocatalytic nano-TiO2 on the survival or die-off of E. coli (e.g. TK2) were investigated under ambient conditions. Experimentally, a 28-h E. coli culture was exposed to photocatalytic nano-TiO2 at various concentrations, e.g., 0 to 1000 mg/L and particle size, e.g., 5 to 500 nm both in darkness and the presence of several light sources including a simulated solar light. Preliminary results indicated that E. coli underwent a two-stage response to nano-TiO2 particles independent of UV light irradiation; a rapid decrease in population density within the first 10 min then slowly decreased upon extended treatment time, e.g., 30-60 min. Results also show that there is bacteria die-off in the presence of nanoscale TiO2 in dark. Generally it appears that the growth rate decreases as the particle size decreases. The presence of light irradiation significantly enhanced the killing of E. coli due to additional photocatalytic activity. Photocatalytic reactions generated hydroxyl radical, which is
Artificial photosynthesis is a desirable critical technology for the conversion of CO2 and H2O, which are abundant raw materials, into fuels and chemical feedstocks. Similar to plant photosynthesis, artificial photosynthesis can produce CO, CH3OH, CH4, and preferably higher hydrocarbons from CO2 using H2O as an electron donor and solar light. At present, only insufficient amounts of CO2-reduction products such as CO, CH3OH, and CH4 have been obtained using such a photocatalytic and photoelectrochemical conversion process. Here, we demonstrate that photocatalytic CO2 conversion with a [email protected] mixture of CaGa4O7-loaded Ga2O3 and the CaO photocatalyst leads to a satisfactory CO formation rate (|835 µmol h−1) and excellent selectivity toward CO evolution (95%), with O2 as the stoichiometric oxidation product of H2O. Our photocatalytic system can convert CO2 gas into CO at |1% CO2 conversion (|11531 ppm CO) at ambient temperatures and pressures. Photocatalytic CO2 reduction requires catalysts that
The photocatalytic activity of hybrid TiO2-C materials prepared by solvothermal synthesis was studied using phenol as test molecule. The influence of furfural, chitosan and saccharose as carbon precursors was verified. Characterization was performed by N2 adsorption isotherms, XRD, DR/UV-vis and SEM. The carbon precursor affects the surface area and the XRD patterns of TiO2-C. First and second order reaction rates approaches were used to estimate the photocatalytic activity. TiO2-C materials showed an increase up to 4.4 higher photoactivity than commercial TiO2. The present results suggest that hybrid TiO2-C nanostructured materials can be potentially used as eco-friendly and low-cost heterogeneous photocatalysts under UV-vis irradiation.. ...
Nanosized titanium dioxide, particularly in the anatase form, exhibits photocatalytic activity under ultraviolet (UV) irradiation. This photoactivity is reportedly most pronounced at the {001} planes of anatase,[44][45] although the {101} planes are thermodynamically more stable and thus more prominent in most synthesised and natural anatase,[46] as evident by the often observed tetragonal dipyramidal growth habit. Interfaces between rutile and anatase are further considered to improve photocatalytic activity by facilitating charge carrier separation and as a result, biphasic titanium dioxide is often considered to possess enhanced functionality as a photocatalyst.[47] It has been reported that titanium dioxide, when doped with nitrogen ions or doped with metal oxide like tungsten trioxide, exhibits excitation also under visible light.[48] The strong oxidative potential of the positive holes oxidizes water to create hydroxyl radicals. It can also oxidize oxygen or organic materials directly. ...
This study combined photocatalytic technology with activated carbon cellulose-paper filter (ACCF) adsorption to decompose gaseous pollutants. Gaseous pollutants were initially adsorbed by activated carbon and could be further decomposed by photocatalytic technology. This study selected acetone (CH3COCH3) as gaseous pollutants. Two market available photocatalysts (photocatalysts¢¹and¢º) were coated on ACCF by impregnation to decompose acetone in a batch photocatlytic reactor. Operating parameters investigated in this study included initial acetone concentration (4.1~10.2 £gM), reaction temperature (40~70¢J), and water vapor (0~20 %). The incident UV light of 365 nm was irradiated by a 20-watt low-pressure mercury lamp placing above the batch photocatalytic reactor. The ACCF coated with TiO2 was placed at the center of the photocatalytic reactor. Acetone was injected into the reactor by a gasket syringe to conduct the photocatalytic tests. Reactants and products were analyzed quantitatively ...
Photocatalytic dye degradation has received more attention as an affordable and effective way to treat the dye polluted water. In the present chapter, we are going to discuss; (i) the preparation and photophysical characterization of g-C3N4 intercalated ZnO\\Mg-Al LDH, a novel ternary nanocomposite, and (ii) its visible light photocatalytic degradation activity against the methylene blue dye. LDHs are 2D materials composed of
节选20篇代表性论文:. 1.Guo, C.S.; Gao, S.W.; Lv, J.P.; Hou, S.; Zhang, Y.; Xu, J., Assessing the photocatalytic transformation of norfloxacin by BiOBr/iron oxides hybrid photocatalyst: Kinetics, intermediates, and influencing factors. Applied Catalysis B: Environmental 2017, 205, 68-77.. 2.Guo, C.S.; Wang, K.; Hou, S.; Wan, L.; Lv, J.P.; Zhang, Y.; Qu, X.D.; Chen, S.Y.; Xu, J., H2O2 and/or TiO2 photocatalysis under UV irradiation for the removal of antibiotic resistant bacteria and their antibiotic resistance genes. Journal of Hazardous Materials 2017, 323, Part B, 710-718.. 3.Gao, S.W.& ;Guo, C.S.& ;Lv, J.P.; Wang, Q.; Zhang, Y.; Hou, S.; Gao, J.F.; Xu, J., A novel 3D hollow magnetic Fe3O4/BiOI heterojunction with enhanced photocatalytic performance for bisphenol A degradation. Chemical Engineering Journal 2017, 307, 1055-1065. (共同一作). 4.Gao, S.W. &; Guo, C.S. &; Hou, S.; Wan, L.; Wang, Q.; Lv, J.P.; Zhang, Y.; Gao, J.F.; Meng, W.; Xu, J., Photocatalytic removal of ...
Developing highly active electrocatalysts for photoelectrochemical water splitting is critical to bringing solar/electrical-to-hydrogen energy conversion processes into reality. Researchers have developed a novel 3D hierarchical hybrid electrocatalyst grown on electrochemically exfoliated graphene. The researchers then further integrated the hybrid nanosheets with a macroporous silicon photocathode, and the results show that it can enable highly active solar-driven photoelectrochemical water splitting in both basic media and real river water.
TY - JOUR. T1 - Photomodulated Supramolecular Chirality in Achiral Photoresponsive Rodlike Compounds Nanosegregated from the Helical Nanofilaments of Achiral Bent-Core Molecules. AU - Kim, Kibeom. AU - Kim, Hanim. AU - Jo, Seong Yong. AU - Araoka, Fumito. AU - Yoon, Dong Ki. AU - Choi, Suk Won. PY - 2015/10/14. Y1 - 2015/10/14. N2 - We prepared a nonchiral mixture of achiral bent-core molecules and photoresponsive rodlike liquid crystalline (LC) molecules. With the help of the isothermal photochemical nematic (N)-isotropic (Iso) phase transition of the photoresponsive rodlike LC molecules, the corresponding phase transition from a dark conglomerate BX phase to another distinguishable dark conglomerate B4 phase took place in the mixture. A large circular dichroism (CD) signal originating from supramolecular chirality was detected in the initial BX phase. On the other hand, the detected CD signal was decreased in the B4 phase after UV irradiation. Interestingly, the decreased CD signal could be ...
Introduction. Inorganic semiconductors emerged as valuable materials due to their wide range of magnetic [1,2], photocatalytic [3], optical [4], and electric [5], properties. These compounds are used for technological applications in medicine [6,7], agriculture [8], and industry [9]. Bismuth oxyhalides (BiOX, where X=F−, Cl−, Br−, or I−) and their derivatives have attracted the attention of researchers worldwide because of their optical [10,11], photocatalytic [12-14], and gas sensing properties [15]. Bismuth oxyhalides, Sillén family members, have a tetragonal structure belonging to P4/nmm space group. In this structure, XBiOBiX bilayers are stacked along the c-axis [16,17]. Also, bismuth oxyhalides can be activated by visible light due to the structural organization and low band gap value (2.0-4.8eV), which is ideal for environmental applications as pollution treatment [18], and development of renewable energy [19,20].. Considerable effort has been made to reduce oxyhalides band gap ...
The Beilstein organic chemistry symposium on photoredox catalysis for novel organic reactions was held at the avendi Hotel in Potsdam on the banks of the Griebnitzsee from April 24th - 26th 2018. The meeting, which had been organized by Markus Antonietti and Peter H. Seeberger, brought together a diverse group of scientists including organic chemists, material scientists and chemical engineers. Around 100 participants from 19 countries had the chance to experience outstanding presentations from leading researchers in the field and were also able to observe the latest developments of talented students and postdoctoral researchers during two well-attended poster sessions. The limited attendance list fostered stimulating discussions and an interdisciplinary interchange which often lasted late until the night. This Beilstein symposium covered a broad range of topics including catalyst development, novel transformations and dedicated technologies for photochemical transformations. Although the first ...
TiO2 has been shown to be a potential candidate for photoinitiated processes, such as dye sensitized solar cells and water splitting in production of H2. The large band gap of TiO2 can be reduced by functionalizing the oxide by adsorbing dye molecules and/or water reduction/oxidation catalysts, by metal/nonmetal doping, and by mixing with another oxide. Due to these methods, several different TiO2‐based complexes can be constructed having different geometries, electronic structures, and optical characteristics. It is practically impossible to test the photocatalytic activity of all possible TiO2‐based complexes using only experimental techniques. Instead, density functional theory (DFT)‐based theoretical simulations can easily guide experimental studies by screening materials and providing insights into the photoactivity of the complexes. The aim of this chapter is to provide an outlook for current research on DFT‐based simulations of TiO2 complexes for dye sensitized solar cells and water
Abstract: TiO2/ AC (activated carbon) composite photocatalysts were prepared by acid catalyzed hydrolysis method followed by calcinations in N2 atmosphere. Photocatalytic activity of TiO2/wAC (w: the mass fraction of AC, %) was investigated through the photocatalytic degradation of phenol, methyl orange, and Cr6+ in the present of TiO2/wAC. The separability of TiO2/AC was determined by gravity-sedimentation. XRD, DRS, FTIR, SEM, and N2 adsorption isotherm were used to characterize the crystal structure, spectra characteristics, and surface properties of the obtained catalysts. The results showed that TiO2/wAC catalysts with optimal AC content 5%(w) exhibited more higher activity than P-25 and TiO2, as well as good decantability, less activity lost after several runs and less sensitive to pH change.Result of DRS revealed no electronic change when AC was added. Better TiO2 distribution and less agglomeration can be achieved when optimal AC content adopted. Result of FTIR suggests that a ...
Fingerprint Dive into the research topics of Development of visible-light activated titanium dioxide films with femtosecond laser. Together they form a unique fingerprint. ...
Anatase nanocrystals were precipitated mainly at the surface of the silica-titania gel films with hot water treatment, whereas the addition of poly(ethylene glycol) (PEG) in the films led to the dispe
Photochemical processes[edit]. When a photosensitiser is in its excited state (3Psen*) it can interact with molecular triplet ... Photochemical reactions[edit]. Excited triplet-state photosensitisers can react via Type-I and Type-II processes. Type-I ... Type-I processes[edit]. Type-I processes can be divided into Type I(i) and Type I(ii). Type I (i) involves the transfer of an ... Type-II processes[edit]. Type-II processes involve the direct interaction of the excited triplet state photosensitiser (3Psen ...
A general photochemical process". Journal of the American Chemical Society. 89 (15): 3932-3933. doi:10.1021/ja00991a064. ISSN ... The di-pi-methane rearrangement is a photochemical reaction of a molecular entity that contains two π-systems separated by a ... Process a is preferred since it leaves benzhydryl odd-electron stabilization intact. Equation 2. The mechanism of the Pratt ... thus inhibiting the Di-pi-Methane process. The cis-trans isomerization proceeds by weakening of a pi-bond and then twisting. ...
Franck's first paper there, co-authored with Edward Teller, was on photochemical processes in crystals. Hans Gaffron became his ... 8-9. Franck, J. (1926). "Elementary processes of photochemical reactions". Transactions of the Faraday Society. 21: 536-542. ... the process by which plants use light to convert carbon dioxide and water into more organic compounds. Biological processes ...
Franck, J. (1926). "Elementary processes of photochemical reactions". Transactions of the Faraday Society. 21: 536-542. doi: ... "Elementary processes of photochemical reactions". Transactions of the Faraday Society. 21: 536-542. doi:10.1039/tf9262100536. ...
A General Photochemical Process" (PDF). J. Am. Chem. Soc. 89 (15): 3932-3933. doi:10.1021/ja00991a064. Wang, C.; Yuan, J.; Li, ... This pattern is consistent with an exchange process whose rate k is close to the frequency separation of the four contributing ... In 1966 W. von Eggers Doering and Joel W. Rosenthal synthesized it by the photochemical rearrangement of cis-9,10- ... magnetic resonance spectroscopy as techniques for the quantitative investigation of dynamic processes. The Cope rearrangement ...
"Methyl Ethyl Ketone Photochemical Processes". Journal of the American Chemical Society. 72 (6): 2810-2811. doi:10.1021/ ... The Norrish type I reaction is the photochemical cleavage or homolysis of aldehydes and ketones into two free radical ... A Norrish type II reaction is the photochemical intramolecular abstraction of a γ-hydrogen (a hydrogen atom three carbon ... A Norrish reaction in organic chemistry is a photochemical reaction taking place with ketones and aldehydes. Such reactions are ...
Lewis, Gilbert N.; Lipkin, David; Magel, Theodore T. (November 1941). "Reversible Photochemical Processes in Rigid Media. A ... The above holds for χ ( 2 ) {\displaystyle \chi ^{(2)}} processes. It can be extended for processes where χ ( 3 ) {\ ... In these processes, the medium has a linear response to the light, but the properties of the medium are affected by other ... The power for this comes from the two pump beams, which are depleted by the process. The frequency of the conjugate wave can be ...
The general process can be divided into four stages: Initiation the process of generating the initial free radical. Propagation ... Tyler, David R. (30 December 2004). "Mechanistic Aspects of the Effects of Stress on the Rates of Photochemical Degradation ... In textiles the process is called phototendering. Technologies have been developed to both accelerate and inhibit this process ... The photo-oxidation process at aliphatic sites is similar to that seen for polyolefins, with the formation of hydroperoxide ...
Photosystem I (PSI) and photosystem II (PSII) work synergistically; through photochemical processes PSII transports electrons ... or transferring the energy to a plant process (photosynthesis). In plants, the photoreceptors cryptochrome and phototropin ...
Further optimization of sulfuric acid technology resulted in the contact process in the 1880s,[3] and the Haber process was ... Photochemical reactions. In this Paterno-Büchi reaction, a photoexcited carbonyl group is added to an unexcited olefin, ... With the development of the lead chamber process in 1746 and the Leblanc process, allowing large-scale production of sulfuric ... Weismantel, Guy E (1999). John J. McKetta (ed.). Encyclopedia of Chemical Processing and Design. 67. CRC Press. p. 109. ISBN ...
"Radiative and photochemical processes in mesospheric dynamics: Part I. Models for radiative and photochemical processes" (PDF ... The first of these, Part I: Models for Radiative and Photochemical Processes, was co-authored with his Harvard colleague and ... This formed the basis of his seminal Radiative and Photochemical Processes in Mesospheric Dynamics that was published in four ... 2.0.CO;2. Lindzen, Richard S (1966). "Radiative and photochemical processes in mesospheric dynamics. Part III. Stability of a ...
The photochemical processes involved are complex but well understood. The key observation is that, ordinarily, most of the ... and in the cleaning processes of delicate electronic equipment. They also occur as by-products of some chemical processes. No ... This is a continuing process that terminates when an oxygen atom recombines with an ozone molecule to make two O 2 molecules. O ... As warm, ozone and NO 2-rich air flows in from lower latitudes, the PSCs are destroyed, the enhanced ozone depletion process ...
... s are made using a photochemical machining process. It starts out with a sheet of steel or invar alloy that is ... The process was used a total of three times, once for each color. (The shadow mask or aperture grille had to be removable and ... Shadow masks are made by photochemical machining, a technique that allows for the drilling of small holes on metal sheets. ... "Anti-doming composition for a shadow-mask and processes for preparing the same". "Shadow mask". http://www.earlytelevision.org/ ...
"Photochemical processes and the environmental impact of petroleum spills". Biogeochemistry. 39 (2): 121-138. doi:10.1023/A: ... The combustion process of petroleum , coal , and wood is responsible for increased occurrence of acid rain. Combustion causes ... Emissions from the petroleum industry occur in every chain of the oil-producing process from the extraction to the consumption ...
1948; 47:91-93 The photochemical reduction process in photosynthesis. In Symposia of the Society for Experimental Biology. C. S ... The photochemical activity of isolated chloroplasts. C. S. French, H. W. Milner, M. L. Koenig, and F. D. H. Macdowall. Carn. ... While processing times are slow, taking 3-10 times longer than that in specialty shaking machines, it works well for easily ... Cell disruption is a method or process for releasing biological molecules from inside a cell. The production of biologically ...
doi:10.1002/cber.191604901176 [2] (1917) About real photochemical processes. Zeitschrift für Physikalische Chemie, Volume 130U ... About the mechanism of photochemical polymerization of anthracene. Natural Sciences (1929) Photochemical to the theory of color ... Natural Sciences (1933) The Colloid Chemistry of Photoanisotrophy (1940) Photochemical Studies on Color Vision Berenblum and ... doi:10.1002/cber.190303601208 [1] (1905) About reversible photochemical reactions in the homogeneous system (1908) About ...
... can be synthesized only by a photochemical process. Phytoplankton in the ocean (such as coccolithophore and Emiliania ... The process is faster in white button mushrooms. Vitamin D3 is produced photochemically from 7-dehydrocholesterol in the skin ... An unambiguous deactivation process". The Journal of Biological Chemistry. 261 (20): 9250-6. doi:10.1016/S0021-9258(18)67647-1 ...
These processes result in both fading of the colorant and strength loss of the substrate. Phototendering, i.e., photochemical ... A colorant molecule, when excited by a photon of sufficient energy, undergoes an oxidation process. In the process the ... Photolysis, i.e., photochemical decomposition is a chemical reaction where the compound is broken down by the photons. This ... Photosensitization, i.e., photochemical sensitization. Exposing dyed cellulosic material, such as plant-based fibers, to ...
Aside from electrolysis driven by photovoltaic or photochemical cells, several thermochemical processes have also been explored ... Solar chemical processes use solar energy to drive chemical reactions. These processes offset energy that would otherwise come ... The Solzinc process under development at the Weizmann Institute of Science uses a 1 MW solar furnace to decompose zinc oxide ( ... Solar induced chemical reactions can be divided into thermochemical or photochemical. A variety of fuels can be produced by ...
Rabinowitch, E (1936). "The collison [sic] mechanism and the primary photochemical process in solutions". Transactions of the ... to the sum of the rate constants for all cage processes. According to mathematical models, Fc is dependent on changes on ...
The print is then processed using traditional photochemical means (usually RA4). After which the photographic print is handled ... Whereas xerography and inkjet printing employ a halftone process and ink to reproduce digital images on paper, digital-C is a ... photographic continuous tone process rather than halftone or error diffusion which are common on offset press or ink-jet. The ...
The upper atmosphere - structure, composition, and dominant physical and photochemical processes. Sound propagation, aurora, ... Buettner, K. J. (1958). Sorption by the earth surface and a new classification of kata-hydrometeoric processes. Journal of ...
This low quantum yield means that other photochemical processes are also occurring. Studies have raised the issue that ... Photochemical and photophysical properties of sunscreens. Mueller SO; Kling M; Arifin Firzani P; et al. (April 2003). " ...
Phonon Mössbauer effect Shpolskii matrix Friedrich, J. J.; D. Haarer (1984). "Photochemical Hole Burning: A Spectroscopic Study ... of Relaxation Processes in Polymers and Glasses". Angewandte Chemie International Edition in English. 23 (2): 113-140. doi: ... in emission when the excited state quickly decays to its zero-point lattice vibration level by means of a radiationless process ...
The EXPOSE-E experiments are: PROCESS, study photochemical organic compounds in Earth orbit. Relevant to comets, meteorites, ... PROCESS The search for organic molecules at the surface of Mars is a top priority of Mars exploration space missions. Therefore ... Photochemical studies in low Earth orbit for organic compounds related to small bodies, Titan and Mars. Current and future ... The PROCESS Experiment: An Astrochemistry Laboratory for Solid and Gaseous Organic Samples in Low-Earth Orbit Archived 2014-01- ...
Friedrich, Josef; Haarer, Dietrich (1984). "Photochemical Hole Burning: A Spectroscopic Study of Relaxation Processes in ...
It is not certain exactly how long it took for Carbutt to standardize his process, but it occurred no later than 1888. A 15- ... Many sources of deterioration in celluloid exist, such as thermal, chemical, photochemical, and physical. The most inherent ... In 1870, John and his brother Isaiah patented a process of making a "horn-like material" with the inclusion of cellulose ... In 1878 Hyatt was able to patent a process for injection moulding thermoplastics, although it took another fifty years before ...
He studies impact processes, atmospheric escape processes, geochemical modelling of atmophiles, and photochemical modelling. He ...
McElwee-White introduced photochemical CVD processes as an alternative, and employed ruthenium-based precursors. Electron beam- ... For the process of metallization of organic thin films, normal thermal CVD processes which require high temperatures usually ... It has been a very attractive process because it is chemically selective process, the material produced is high-quality and ... "Photochemical CVD of Ru on Functionalized Self-Assembled Monolayers from Organometallic Precursors," Johnson, K.R.; Arevalo ...
... an agent for carrying out the process and the fibre material treated with the agent are described. ... A process for the photochemical stabilization of undyed and dyed polyamide fibre material or blends thereof with other fibre ... Process for the photochemical stabilization of undyed and dyed polypropylene fibres. US5069681 *. Dec 26, 1990. Dec 3, 1991. ... Process for the photochemical and thermal stabilization of polyamide fibres having an affinity for acid and basic dyes, and of ...
... cross-linked hydrogel contacting lactic acid solution can be used for controlling the thickness of the photochemical pattering ... thus serving as a biocompatible positive photoresist suitable for photochemical patterning. Alternatively, surface etching of ... Article Processing Charges Pay an Invoice Open Access Policy Terms of Use Terms and Conditions Privacy Policy Contact MDPI Jobs ... Processes EISSN 2227-9717 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert ...
... Azadeh Asadi and ... It was observed that UV/H2O2/TiO2 process did not have any advantages over each of the other processes alone. The ... was investigated by various photo-induced oxidation processes such as UV/H2O2 and UV/TiO2 as well as biological processes and ...
Interface processes in photochemical water splitting: Theory meets experiment. CECAM-HQ-EPFL, Lausanne, Switzerland. * ... We remark that the workshop is focused on interfacial processes in the context of photo-induced water splitting, but very ... Gathering together the most active experts in method development and predictive simulation of photo-induced catalytic processes ... Clearly, characterization of all these processes necessitates interplaying of different disciplines: synthesis, quantum ...
Photochemical control of bacterial signal processing using a light-activated erythromycin Laura Gardner,a Yan Zou,a Alexandria ... Photochemical control of bacterial signal processing using a light-activated erythromycin L. Gardner, Y. Zou, A. Mara, T. A. ... enable photochemical activation. of gene expression in E. coli. We applied this photochemical gene switch to the construction ...
Mechanisms of photophysical processes and photochemical reactions in polymers: theory and applications. ... Mechanisms of photophysical processes and photochemical reactions in polymers: theory and applications. ... gb-gplus-shareMechanisms of photophysical processes and photochemical reactions in polymers. ... mechanism methyl methacrylate molecule monomer naphthalene occurs oxidation peroxide phenyl phosphorescence photochemical ...
... of an additive gas in addition to the source gas into a reaction vessel and particularly the provision of photo CVD process ... rate and improvement of film quality and removing restriction of light source and source gas in the photo CVD process, the ... film formation processes represented by PVD process (Physical Vapor Deposition process) and CVD process (Chemical Vapor ... This invention relates to a photochemical vapor deposition process (hereinafter referred to as photo CVD process) for forming a ...
This was coincident with the initial degradation products coming from the processes action. Although both processes exhibited ... Afterward, the ability of the processes to mineralize losartan and remove the phyto-toxicity was tested. It was found that in ... Initially, special attention was paid to the degrading action of the processes. Then, theoretical analyses on Fukui function ... relevant results on the elimination of a representative pharmaceutical in fresh urine by two advanced oxidation processes. ...
... approaches in order to improve different processes in comparison to solution, in terms of kin ... Photophysical and photochemical processes in 3D self-assembled gels as confined microenvironments R. Pérez-Ruiz and D. Díaz ... Photophysical and photochemical processes in 3D self-assembled gels as confined microenvironments ... In this respect, investigation of photophysical and photochemical processes in soft gel materials has recently emerged as a new ...
New Materials to Solve Energy Issues through Photochemical and Photophysical Processes: The Kinetics Involved. By Tatiana Duque ... embed/advanced-chemical-kinetics/new-materials-to-solve-energy-issues-through-photochemical-and-photophysical-processes-the- ... embed/advanced-chemical-kinetics/new-materials-to-solve-energy-issues-through-photochemical-and-photophysical-processes-the- ... New Materials to Solve Energy Issues through Photochemical and Photophysical Processes: The Kinetics Involved, Advanced ...
Emissions Inventory and Process Reconciliation Using Molecular Markers and Hybrid/Inverse Photochemical Modeling with Direct ...
In the present study the non-photochemical quenching (NPQ) of four biofilm-forming and two planktonic green algae was ... quenching and xanthophyll cycle activities in six green algal species suggest mechanistic differences in the process of excess ... In the present study the non-photochemical quenching (NPQ) of four biofilm-forming and two planktonic green algae was ...
Laboratory photochemical processing of aqueous aerosols: formation and degradation of dicarboxylic acids, oxocarboxylic acids ... Enrichment of 13C in diacids and related compounds during photochemical processing of aqueous aerosols: New proxy for organic ... Enrichment of 13C in diacids and related compounds during photochemical processing of aqueous aerosols: New proxy for organic ... Sources and formation processes of water-soluble dicarboxylic acids, ω-oxocarboxylic acids, α-dicarbonyls, and major ions in ...
Advanced Oxidation Processes (AOPs): Principles, Reaction Mechanisms, Reactor Concepts - Author: Oppenländer, Thomas - Price: ... Photochemical Purification of Water and Air: Advanced Oxidation Processes (AOPs): Principles, Reaction Mechanisms, Reactor ... Invaluable to Environmental Chemists, Water Chemists and Process Engineers.. Keywords: SCIENCE / Chemistry / Organic SCI013040 ... Bioremediation and Natural Attenuation: Process Fundamentals and Mathematical Models. Alvarez, Pedro J. ...
... formation through photochemical cloud processing. A high-resolution time-of-flight chemical ionization mass spectrometer using ... Photochemical cloud processing of primary wildfire emissions as a potential source of secondary organic aerosol ... Photochemical cloud processing of primary wildfire emissions as a potential source of secondary organic aerosol. Environmental ... formation through photochemical cloud processing. A high-resolution time-of-flight chemical ionization mass spectrometer using ...
Photochemical Treatment vs a Continuous Coupled Photofenton-Biological Process for the Degradation of a Biorecalcitrant ... Photochemical Treatment vs a Continuous Coupled Photofenton-Biological Process for the Degradation of a Biorecalcitrant ...
Learn about the photo chemical machining process which is a unique technology that produces precision metals parts by ... The Photochemical Machining Process. The photochemical machining (PCM) process consists of several important steps. Each step ... The developing process forms an adherent, durable image on both sides of the metal, which is now ready for the etching process. ... At this point in the process, the sheets of metal are processed in a yellow safe-light environment. ...
By means of the process of this invention it is possible to prevent wastewater from being contaminated with copper-containing ... There is disclosed a process for the photochemical stabilization of dyed polyamide fibre materials, which comprises treating ... Process for the treatment of textile fibre materials US4408995A (en) * 1981-02-11. 1983-10-11. Ciba-Geigy Corporation. Process ... Process for the photochemical stabilization of undyed and dyed polyamide fibre material and blends thereof with copper complex ...
... and this photochemical change causes the sensation of light. The process is reversed by a thermal-i.e., non-photochemical- ... The photochemical process. For the energy of light to exert its effect it must be absorbed; it has been stated above that the ... The mixing of pigments is essentially a subtractive process, however, as opposed to the additive process of throwing ... The transduction process. Immediately after absorption of a quantum, the rhodopsin molecule is changed into a substance called ...
Co-occurrence of photochemical and microbiological transformation processes in open-water unit process wetlands. Environmental ... Co-occurrence of photochemical and microbiological transformation processes in open-water unit process wetlands. / Prasse, ... Co-occurrence of photochemical and microbiological transformation processes in open-water unit process wetlands. ... title = "Co-occurrence of photochemical and microbiological transformation processes in open-water unit process wetlands", ...
Proton-Coupled Electron Transfer Cleavage of Heavy-Atom Bonds in Electrocatalytic Processes. Cleavage of a C-O Bond in the ... Iron Porphyrin-Catalyzed Reduction of CO 2 . Photochemical and Radiation Chemical Studies journal, January 1997 * Grodkowski, J ... Iron Porphyrin-Catalyzed Reduction of CO 2 . Photochemical and Radiation Chemical Studies journal, January 1997 * Grodkowski, J ... Photocatalysis of oligo(p-phenylenes): photochemical reduction of carbon dioxide with triethylamine journal, May 1992 * ...
Steps in photochemical processes. The excited state. A photochemical change takes place in two steps. Imagine that a light beam ... This process is just the reverse of the process by which the atom or molecule first became excited. If the atom or molecule ... This process, called chemiluminescence, is illustrated by various glow-in-the-dark objects. Another possibility is for the ... The formation of ozone is just one example of the many kinds of photochemical changes that can occur. When solar energy breaks ...
2. Photochemical Processes. In typical free radical photopolymerization systems, the kinetic model describing what takes place ... In the above we have presented the main photochemical processes which take place in general free-radical photopolymerisation ... In Section 2, we briefly review the photochemical processes generally occurring during the fabrication of refractive index ... an understanding of the photochemical and photophysical processes, which occur during photopolymerisation, is extremely ...
Photochemical processes[edit]. When a photosensitiser is in its excited state (3Psen*) it can interact with molecular triplet ... Photochemical reactions[edit]. Excited triplet-state photosensitisers can react via Type-I and Type-II processes. Type-I ... Type-I processes[edit]. Type-I processes can be divided into Type I(i) and Type I(ii). Type I (i) involves the transfer of an ... Type-II processes[edit]. Type-II processes involve the direct interaction of the excited triplet state photosensitiser (3Psen ...
4 shows a photochemical processing system 100 according to the invention. The photochemical processing system 100 comprises the ... 12. Photochemical processing system (100) for photochemically processing contamination in a fluid (30), the photochemical ... As such, the known photochemical reactor is arranged for performing a specific photochemical process. In the photochemical ... influence the photochemical process of the photochemical processing system 100. For example, the flow speed of the fluid 30 may ...
Sulphate of Copper Process. The Detection of "Ghosts" in Prisms-II. A Method of Developing Prisms Free from Undesirable ...
Ammonia removal from leachate by photochemical process using h2o2 . José Euclides Stipp Paterniani ; Giovani Archanjo Brota ; ... Ammonia removal from leachate by photochemical process using h2o2 - Descarga este documento en PDF. Documentación en PDF para ... it was studied the optimization of the photochemical process using H2O2-UV in order to reduce the concentration of ammonia in ... 3625-4212 Ammonia removal from leachate by photochemical process using H2O2 (doi:10.4136-ambi-agua.136) Núbia Natália de Brito1 ...
The 28th Informal Symposium on Kinetics and Photochemical Processes in the Atmosphere will take place at the University of ... Please examine the full conference program for the 28th Informal Symposium on Kinetics and Photochemical Processes in the ... 28th Informal Symposium on Kinetics and Photochemical Processes in the Atmosphere (2011). ...
Photochemical Processes* * Photosensitizing Agents / pharmacology* * Polyethyleneimine / chemistry * Polylysine / chemistry * ... Photochemical internalization (PCI): a technology for drug delivery Methods Mol Biol. 2010;635:133-45. doi: 10.1007/978-1-60761 ... Photochemical internalization (PCI) is a novel technology for release of endocytosed macromolecules into the cytosol. The ...
Photochemical reaction, a chemical reaction initiated by the absorption of energy in the form of light. The consequence of ... Many other processes in nature are photochemical. The ability to see the world starts with a photochemical reaction in the eye ... In the simplest photochemical process, excited states can emit light in the form of fluorescence or phosphorescence. In 1565, ... Photochemical reactions and the properties of excited states are also critical in many commercial processes and devices. ...
  • After a brief introduction to the realm of photochemistry, electronically excited state formation and the different pathways of excited state deactivation, the book focuses on the theoretical basis and the practical aspects related to the most widely used photophysical and photochemical techniques, from absorption to time-resolved emission techniques with polarized light. (indigo.ca)
  • The Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques not only discusses the latest advances of the field of supramolecular photochemistry but it also offers technical and operative details useful in the laboratory. (indigo.ca)
  • Written as an authoritative guide for researchers involved in the development of bioinorganic photochemical processes, Bioinorganic Photochemistry is also accessible to scientists new to the field, and will be a key reference source for advanced courses in inorganic, and bioinorganic chemistry. (wiley.com)
  • Importantly, electronically excited carbonyls can also be generated by chemiexcitation and undergo further typical photochemical processes, i.e. without photoexcitation, which consequently was independently called by G. Cilento (University of São Paulo) 10 and by E. H. White (Johns Hopkins University) as " photochemistry in the dark " 11 . (nature.com)
  • In typical free radical photopolymerization systems, the kinetic model describing what takes place involves five main processes: (I) initiation, (II) propagation, (III) termination, (IV) inhibition, and (V) chain transfer, each of which may involve several physicochemical reactions. (hindawi.com)
  • We discuss the major chemical reactions taking place in each process below [ 12 - 16 ]. (hindawi.com)
  • Photochemical reactions and the properties of excited states are also critical in many commercial processes and devices. (britannica.com)
  • Absorbed by a molecule from this radiation can result in the formation of active species, thus initiating photochemical reactions that lead to the noxious products characteristic of smog. (scribd.com)
  • One of the very important reactions of peroxyl radicals are there reaction with NO, produced in the photochemical dissociation of NO2. (scribd.com)
  • 212 Mechanisms of photochemical reactions in solution. (spie.org)
  • From my own photochemical experiences, I can assume that the results will provide plenty of material to work on - these sorts of reactions can take drastically different courses all of a sudden. (sciencemag.org)
  • In this respect, investigation of photophysical and photochemical processes in soft gel materials has recently emerged as a new and promising research field oriented towards expanding their applications in important areas such as photovoltaics, photocatalysis and phototherapy. (rsc.org)
  • New Materials to Solve Energy Issues through Photochemical and Photophysical Processes: The Kinetics Involved, Advanced Chemical Kinetics Muhammad Akhyar Farrukh, IntechOpen, DOI: 10.5772/intechopen.70467. (intechopen.com)
  • The Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques provides a comprehensive view of the most commonly used photochemical and photophysical techniques and their applications to the study of supramolecular systems. (indigo.ca)
  • The degradation of aqueous methyl tert -butyl ether (MTBE) at relatively high concentrations was investigated by various photo-induced oxidation processes such as UV/H 2 O 2 and UV/TiO 2 as well as biological processes and their combination. (hindawi.com)
  • Established in 2004 as a leading supplier specializing in advanced oxidation processes (AOP), UV and ozone integrated systems, ESCO International has designed, built and delivered large AOP plants, ozone and UV system as well as AOP pilot units worldwide. (environmental-expert.com)
  • ESCO International has established itself as one of the top contract Advanced Oxidation Processes suppliers by providing complete design & engineering, cost reduction, quality control and services. (environmental-expert.com)
  • ESCO International's engineered solutions will make the difference in your design capabilities and has the know-how and experience with advanced oxidation processes and ozone systems. (environmental-expert.com)
  • The aim of the company was to develop, build, test and supply complete advanced oxidation processes and ozone systems suitable for industrial, municipal and commercial use. (environmental-expert.com)
  • ESCO International solutions & technologies provide an innovative portfolio of technical services and equipment, specializing in Ozone, UV and Advanced Oxidation Processes (AOP) for drinking water, municipal & industrial wastewater treatment, ground water remediation, gas effluent and odour treatment. (environmental-expert.com)
  • This has inspired scientists to develop spatially micro- and nanoreactors by 'bottom-up' approaches in order to improve different processes in comparison to solution, in terms of kinetics, selectivity or processability. (rsc.org)
  • The 28th Informal Symposium on Kinetics and Photochemical Processes in the Atmosphere will take place at the University of California at Irvine (UCI) on March 3, 2011 in the UCI Student Center , Pacific Ballroom D (directions are given below). (uci.edu)
  • Please examine the full conference program for the 28th Informal Symposium on Kinetics and Photochemical Processes in the Atmosphere. (uci.edu)
  • Differences of the energies of local minima and connecting transition structures determine the rates of interconversion, i.e., the chemical kinetics of the process. (pnas.org)
  • The purpose of this study was to investigate the efficiency of photochemical and sonochemical processes combined with hydrogen peroxide in removal of DB71 from aqueous solution. (bvsalud.org)
  • We remark that the workshop is focused on interfacial processes in the context of photo-induced water splitting, but very similar challenges are shared by (and limiting) many other technologies, such as the synthesis of chemicals and fuels, or the degradation of environmental pollutants assisted by solar energy. (cecam.org)
  • For instance, light-activated excitation of rhodopsin ( bacteriorhodopsin ) molecules, involved in the hyperpolarization process of the cell membrane, can either generate nerve impulses, ATP synthesis, or regulate embryogenesis [1-5]. (thefreedictionary.com)
  • The competition addresses technological environmental issues of design, synthesis, processing, and the production and use of products in continuous and discrete manufacturing industries. (epa.gov)
  • Nevertheless, the need for high-energy ultraviolet radiation in most organic photochemical processes has limited both the practicality and environmental benefits of photochemical synthesis on industrially relevant scales. (nature.com)
  • Companies cited for their interest in photochemical synthesis without divulging details of their actives AZ, BASF, Bayer, Bristol Myers Squibb, Clariant & GSK. (sciencemag.org)
  • Photochemical smog is formed when emissions containing nitrogen oxide, such as car exhaust, interact with volatile organic compounds in the presence of sun. (reference.com)
  • The process by which photochemical smog is formed is shown in Figure 1. (scribd.com)
  • The invention relates to a photochemical reactor (12). (patentsencyclopedia.com)
  • The photochemical reactor comprises a vessel (20) comprising the fluid (30), a light source (40) for generating UV-radiation (UV1) and emitting it towards the fluid, and a luminescent material (50) arranged between the light source and the fluid for converting at least part of the UV-radiation emitted by the light source to further UV-radiation (UV2) having an increased wavelength compared to the UV-radiation. (patentsencyclopedia.com)
  • The luminescent material is removably connected to the photochemical reactor and is separate from the light source. (patentsencyclopedia.com)
  • By having the luminescent material removably connected to the photochemical reactor, separate from the light source, the luminescent material may be exchanged with new luminescent material if the current luminescent material has degraded. (patentsencyclopedia.com)
  • 2. Photochemical reactor (10, 12, 14, 16) as claimed in claim 1, wherein the light source (40) is removably connected to the photochemical reactor (10, 12, 14, 16) and is separate from the luminescent material (50). (patentsencyclopedia.com)
  • 4. Photochemical reactor (10, 12, 14, 16) as claimed in claim 1, wherein a further fluid (30, 35) may flow between the light source (40) and the luminescent material (50). (patentsencyclopedia.com)
  • 5. Photochemical reactor (10, 12, 14, 16) as claimed in claim 3, wherein the further fluid (30) is identical to the fluid (30). (patentsencyclopedia.com)
  • 6. Photochemical reactor (10, 12, 14, 16) as claimed in claim 1 wherein the fluid (30) flows through the photochemical reactor (10, 12, 14, 16). (patentsencyclopedia.com)
  • 7. Photochemical reactor (10, 12, 14, 16) as claimed in claim 1, wherein the light source (40) is a dielectric barrier discharge lamp (40). (patentsencyclopedia.com)
  • 8. Photochemical reactor (10, 12, 14, 16) as claimed in claim 1, wherein the light source (40) is arranged in a protective sheath (22) having a wall at least partially transparent to UV-radiation (UV1), the luminescent material (50) being arranged on the wall of the protective sheath (22). (patentsencyclopedia.com)
  • 9. Photochemical reactor (10, 12, 14, 16) as claimed in claim 1, wherein the UV-radiation (UV1) comprises a wavelength below 200 nanometers and wherein the further UV-radiation (UV2) comprises a wavelength below 300 nanometers. (patentsencyclopedia.com)
  • A photochemical reactor with the capacity of 1.7 liters equipped with refrigeration system and recirculation of leachate was employed in the research. (duhnnae.com)
  • A photochemical reactor is divided into a first section suitable for containing a volume of fluid to be reacted and a second section having at least one light transmitting wall. (google.es)
  • The purpose of this study was to investigate the efficiency of the photochemical processes combined with UV/H2O2 and UV/TiO[2] in removal of Acid Red 18 dye from aqueous solutions in a batch reactor. (bvsalud.org)
  • The process is particularly applicable to the treatment of off gases from a nuclear reactor or reprocessing plant. (dtic.mil)
  • We investigated the gas-phase chemical composition of biomass burning (BB) emissions and their role in aqueous secondary organic aerosol (aqSOA) formation through photochemical cloud processing. (frames.gov)
  • Photochemical degradation of hydrophilic xenobiotics in the UV/H2O2-process. (kit.edu)
  • The microbiological processes occurring in the photoreactor are responsible for transforming the substrates (microbial pollutants) which is consumed during the photochemical reaction and the photoinduced processes (either direct or sensitized) lead to the degradation of faecal coliform bacteria with a concomitant reduction in the bacteria's activity. (thefreedictionary.com)
  • However, the mechanisms of PRI changes in the first minutes of illumination have not been sufficiently studied, and their elucidation can be of significant fundamental and applied value, as field measurements of photochemical index are performed in the conditions of an unstable illumination by sunlight. (eurekalert.org)
  • It is this last property that is crucial in the most important of all photochemical processes, photosynthesis , upon which almost all life on Earth depends. (britannica.com)
  • Such acidification is a key step in the photosynthesis and, thus, in the production processes of plants. (eurekalert.org)
  • This review focuses on the chloroplast, which harbors the pathway of arguably the most important biochemical process for life on earth, photosynthesis. (frontiersin.org)
  • A process for the photochemical stabilization of undyed and dyed polyamide fibre material or blends thereof with other fibre materials, which comprises treating the fibre material with a mixture of (A) an organic copper complex, (B) a light stabilizer and, if desired, (C) an antioxidant, an agent for. (google.com)
  • Process a is preferred since it leaves benzhydryl odd-electron stabilization intact. (wikipedia.org)
  • Ozone protects Earth's surface from intense, deep ultraviolet (UV) irradiation , which is damaging to DNA and is formed in the stratosphere by a photochemical dissociation (separation) of molecular oxygen (O 2 ) into individual oxygen atoms, followed by subsequent reaction of those oxygen atoms with molecular oxygen to produce ozone (O 3 ). (britannica.com)
  • Photochemical internalization (PCI) is a novel technology for release of endocytosed macromolecules into the cytosol. (nih.gov)
  • Photochemical internalization (PCI) provides an emerging technology to route endocytosed material to the cytosol of cells, based on light-induced disruption of endosomal membranes using a photosensitizing compound. (frontiersin.org)
  • Cyanide chemistry: precious metals processing and waste. (cdc.gov)
  • Laser Processing and Chemistry gives an overview of the fundamentals and applications of laser--matter interactions, in particular with regard to laser material processing. (springer.com)
  • It begins with a basic coverage of chemistry and biochemistry, environmental chemical processes, and toxicology. (routledge.com)
  • See Light Sensitive Systems: Chemistry and Application of Nonsilver Halide Photographic Processes, J. Kosar, J. Wiley and Sons (New York, 1965) pages 158-193. (google.com.au)
  • Senior scientist IPCF CNR, Bari PhD in Chemistry 1997 at University of Bari (Italy), Currently responsible at CNR IPCF Bari Division for the material chemistry activities aiming to design, fabricate and process inorganic solids at the nanoscale for obtaining nanostructured and multifunctional materials both for fundamental and application studies. (cnr.it)
  • Expertise in material chemistry activities aiming to design, fabricate and process inorganic solids at the nanoscale. (cnr.it)
  • Not necessarily difficult from a process stand point, very amenable to flow chemistry. (sciencemag.org)
  • This review summarizes research on the electrochemical and photochemical reduction of CO₂ using a variety of iron and cobalt porphyrins, phthalocyanines, and related complexes. (osti.gov)
  • article{osti_1182538, title = {A review of iron and cobalt porphyrins, phthalocyanines, and related complexes for electrochemical and photochemical reduction of carbon dioxide}, author = {Manbeck, Gerald F. and Fujita, Etsuko}, abstractNote = {This review summarizes research on the electrochemical and photochemical reduction of CO₂ using a variety of iron and cobalt porphyrins, phthalocyanines, and related complexes. (osti.gov)
  • These processes which may be termed as "state of the art technologies" are membrane separation processes, ultrasonic, photochemical and electrochemical processes. (intechopen.com)
  • Once the CAD file has been received, PEI's tooling engineers will redraw the part in its entirety, modifying the dimensions to compensate for the unique characteristics of the PCM etching process. (photofabrication.com)
  • All features must be compensated for surface and lateral etching, which happen simultaneously during the etching process. (photofabrication.com)
  • Light-exposed areas are dissolved, exposing parts of the silicon dioxide layer, which are removed by an etching process (c). (britannica.com)
  • The areas of silicon exposed by the etching process are changed from p-type (pink) to n-type (yellow) by exposure to either arsenic or phosphorus vapour at high temperatures (d). (britannica.com)
  • An opening is etched down to the p-type silicon, using a reverse mask with the lithography-etching process (g). (britannica.com)
  • Does your product need photo etching processes? (iqsdirectory.com)
  • Our products are produced using a wide variety of manufacturing methods including photochemical etching and chemical plating. (iqsdirectory.com)
  • The present invention relates to the process of selectively exposing matter to a specific wavelength of electromagnetic energy in sufficient flux density per wavelength to cause or promote a desired effect. (google.ca)
  • This invention relates generally to processes for the separation of noble gases and more specifically to processes for the separation of xenon from a gaseous mixture containing krypton. (dtic.mil)
  • Although demonstrating the functional significance of C-terminal D1 processing in PSII biogenesis, our study reveals an unsuspected link between D1 maturation and PSII supercomplex assembly in land plants, opening an avenue for exploring the mechanism for the association of light-harvesting complexes with the PSII core complexes. (pnas.org)
  • The process starts with PSII initiation complexes (D2, PsbE, PsbF, and PsbI), and then D1 and CP47 are sequentially recruited to form CP47-RC complexes, followed by addition of PsbH, PsbM, PsbTc, and PsbR subunits. (pnas.org)
  • Then, optimum pH was determined which was 7 for photochemical and 3 for sonochemical process in constant condition. (bvsalud.org)
  • However, Irving and Reid were unable to obtain any direct evidence that phenyl free radicals are produced by photodecomposition of diphenyliodonium iodide in chloroform solution with methylmethacrylate monomer, and stated that the increased formation of iodine and especially the formation of benzene are the most striking features which distinguish the photochemical decomposition of diphenyliodonium iodide in chloroform from its thermal decomposition. (google.com.au)
  • This process is just the reverse of the process by which the atom or molecule first became excited. (encyclopedia.com)
  • If the atom or molecule gives off its excess energy almost immediately, the material in which it is contained glows very briefly, a process known as fluorescence. (encyclopedia.com)
  • The ability to see the world starts with a photochemical reaction in the eye , in which retinal, a molecule in the photoreceptor cell rhodopsin , isomerizes (or changes shape) about a double bond after absorbing light. (britannica.com)
  • Methane (CH4) is one of the least active hydrocarbons in terms of forming smog, it will be used here to show the smog formation process because it is the simplest hydrocarbon molecule. (scribd.com)
  • Photoionization is the physical process in which an incident photon ejects one or more electrons from an atom, ion or molecule. (wikipedia.org)
  • Teixeira Pelegrini, Ronaldo Ammonia removal from leachate by photochemical process using H2O2 Ambiente & Água - An Interdisciplinary Journal of Applied Science, vol. (duhnnae.com)
  • [email protected] 3 Center for Agricultural Services CCA - Federal University of São Carlos (UFSCAR) E-mail: [email protected] ABSTRACT In this work, it was studied the optimization of the photochemical process using H2O2-UV in order to reduce the concentration of ammonia in leachate. (duhnnae.com)
  • A Photochemical Method for the Separation of Mixtures of Xenon and Krypton. (dtic.mil)
  • Hydrocarbons and Photochemical Smog. (routledge.com)
  • The rocks are water ice and the lakes are methane and light hydrocarbons, yet we see processes very similar to what we see on Earth. (newscientist.com)
  • The di-pi-methane rearrangement is a photochemical reaction of a molecular entity that contains two π-systems separated by a saturated carbon atom (a 1,4-diene or an allyl-substituted aromatic ring), to form an ene- (or aryl-) substituted cyclopropane. (wikipedia.org)
  • The mechanism of the Barrelene to Semibullvalene transformation The dependence of the success of the Di-pi-Methane rearrangement on singlet versus triplet multiplicity arises primarily from the Free-Rotor Effect The triplet acyclic 1,4-dienes are free to undergo cis-trans interconversion of the diene double bonds (i.e. free-rotation) thus inhibiting the Di-pi-Methane process. (wikipedia.org)
  • The photochemically allowed [1,7]-sigmatropic hydrogen migration (H shift) in CHT is a classical example of a pericyclic reaction associated with internal conversion processes. (kit.edu)
  • Photochemical reaction , a chemical reaction initiated by the absorption of energy in the form of light . (britannica.com)
  • Photography and xerography are both based upon photochemical processes, while the manufacture of semiconductor chips or the preparation of masks for printing newspapers relies on UV light to destroy molecules in selected regions of polymer masks. (britannica.com)
  • After 150 min of oxidation (approximatively 1 day of cloud processing), oxalate accounted for 13-16% of total dissolved organic carbon. (frames.gov)
  • Within a semiconductor crystal lattice, thermal excitation is a process where lattice vibrations provide enough energy to move electrons to a higher energy band. (wikipedia.org)
  • In contrast, removal of acyclovir and lamivudine was mainly attributable to slower microbial processes (t1/2,bio = 74 and 120 h, respectively). (bath.ac.uk)
  • This book offers in-depth insights into the photochemical behavior of multicomponent polymeric-based materials, with a particular emphasis on the photodegradation and photostabilization of these materials. (springer.com)
  • However, the word "photoisomerization" usually indicates a reversible process. (wikipedia.org)
  • 118 Reversible photochemical processes in rigid media. (spie.org)
  • His research interests involve studying the fate and transport of both air and water-borne pollutants in the natural and built environment, as well as the development of passive treatment processes. (tcd.ie)
  • The fate of anthropogenic trace organic contaminants in surface waters can be complex due to the occurrence of multiple parallel and consecutive transformation processes. (bath.ac.uk)
  • and the application of the "electrotype process in conducting organic analysis" (1843). (encyclopedia.com)
  • Here we report functional characterization of the Arabidopsis gene encoding D1 C-terminal processing enzyme (AtCtpA) in the chloroplast thylakoid lumen. (pnas.org)
  • In this mini review we summarize the current status in the field and the open questions that need to be addressed in order to understand how pH gradients are maintained, how this is interconnected with other transport processes and what this means for chloroplast function. (frontiersin.org)
  • Moreover, there are a lot of review article or book chapters on textile wastewater treatment processes individually based on each conventional process such as coagulation, adsorption, chemical oxidation, and biological decolorization. (intechopen.com)
  • Though not a treat to the global atmosphere as such, in some urban areas photochemical smog is highly detrimental to health and to the quality of life. (scribd.com)
  • Estimated releases of 12 pounds (0.01 metric tons) of bromoform to the atmosphere from 3 domestic manufacturing and processing facilities in 2002, accounted for about 3% of the estimated total environmental releases (TRI02 2004). (cdc.gov)
  • One of such indices is the photochemical reflectance index (PRI), which is calculated based on the reflection of light by the plant at wavelengths of 531 and 570 nm. (eurekalert.org)
  • One of the most common urban air pollution problems in the production of photochemical smog. (scribd.com)
  • Tropospheric ozone is a by-product of the photochemical (light-induced) processes associated with air pollution. (nasa.gov)
  • A new generation of cleaner industrial manufacturing and processing technologies is needed that supports pollution prevention, efficient resource use, and industrial ecology. (epa.gov)
  • This competition is designed to address pollution prevention processes, methodologies, and technology research. (epa.gov)
  • In the present study the non-photochemical quenching (NPQ) of four biofilm-forming and two planktonic green algae was investigated by fluorescence measurements, determinations of the light-driven proton gradient and determination of the violaxanthin cycle activity by pigment analysis. (nih.gov)
  • Dr. Vladimir Melezhik of RUDN University is engaged in calculations of resonant phenomena and collision processes in ultracold quantum gases. (phys.org)
  • Such methods could allow modeling with completely controlled quantum systems of complex processes in solid-state physics and high-energy physics. (phys.org)
  • One of the areas of our work is a numerical study of ultracold quantum systems using hybrid atomic-ion traps, offering new possibilities for modeling some actual processes of solid state physics, elements of quantum computing and precision physics research," the scientist concluded. (phys.org)
  • Southeast Texas Photochemical Modeling Technical Committee An advisory group to assist the TCEQ with technical and scientific issues related to air quality modeling and analysis in the Houston-Galveston-Brazoria and Beaumont-Port Arthur areas. (texas.gov)
  • The University of North Carolina at Chapel Hill's outdoor environmental photochemical reaction chamber was used to generate exposure atmospheres. (thefreedictionary.com)
  • Vertex: Uniqsis FlowSyn to generate photochemical libraries. (sciencemag.org)
  • In this study, the removal of five antiviral drugs (abacavir, acyclovir, emtricitabine, lamivudine and zidovudine) via both bio- and phototransformation processes, was investigated in laboratory microcosm experiments simulating an open-water unit process wetland receiving municipal wastewater effluent. (bath.ac.uk)
  • Prior to joining at Trinity College in 1999, he spent several years working in the UK water industry on the design of water and wastewater treatment processes for urban populations. (tcd.ie)
  • 3A offers specialised thermal-resistant preservative and antioxidant blends that ensure the freshness of products that are processed at high temperatures such as cooking oils and fats. (foodprocessing-technology.com)
  • The formation of ozone is just one example of the many kinds of photochemical changes that can occur. (encyclopedia.com)
  • Union Process, Inc., known globally as a manufacturer of particle size reduction and dispersing equipment, as well as a supplier of grinding media and materials characterization services for a broad range of research and industrial applications, has built a laboratory-sized Q-2 Circulation Attritor for a customer who will process a chocolate coating for ice cream. (thomasnet.com)
  • The most promising approach to the analysis of the plant status is to measure the reflected light in the visible range, since the reflectivity of the plants is closely related to their physiological and biochemical processes and the measurement of the reflected light is relatively simple from the technical point of view," says Vladimir Sukhov, Head of the Electrophysiology Laboratory at the UNN Institute of Biology and Biomedicine. (eurekalert.org)
  • The process may be conducted using starting materials that are readily commercially available and/or that may be reacted safely in standard laboratory equipment so that capital cost savings may be seen. (freepatentsonline.com)
  • In Section 2 , we briefly review the photochemical processes generally occurring during the fabrication of refractive index structures in free-radical photopolymerisation material systems. (hindawi.com)
  • Gathering together the most active experts in method development and predictive simulation of photo-induced catalytic processes on one side, and the leading experimentalists operating in the WOX field on the other side, we will discuss current methodological limitations and open issues toward a quantitative modelling of interfacial processes from first principles with the ambitious purpose of defining precise short-to-medium term goals toward higher device efficiencies. (cecam.org)
  • Herein, we summarize the few examples dealing with intragel photo-induced physical and chemical processes involving embedded reactants that do not participate in the assembly of the gel network. (rsc.org)
  • Erythromycin binds to MphR(A), causing release of the PmphR promoter, activating expression of the 2′-phosphotransferase Mph(A). We engineered the MphR(A)/promoter system to, in conjunction with a light-activatable derivative of erythromycin , enable photochemical activation of gene expression in E. coli . (rsc.org)
  • We applied this photochemical gene switch to the construction of a light-triggered logic gate, a light-controlled band-pass filter, as well as spatial and temporal control of gene expression. (rsc.org)
  • At this point in the process, the sheets of metal are processed in a yellow safe-light environment. (photofabrication.com)
  • Since this change was originally made possible by absorbed light energy, it is known as a photochemical change. (encyclopedia.com)
  • Both fluorescence and phosphorescence are examples of the general process of light emission by excited materials known as luminescence. (encyclopedia.com)
  • Since the seventies, it is known that UV light irradiation as well as by sunlight yields a photochemical conversion of trans - to cis -ZEN. (zib.de)
  • A knock-down mutant expressing about 2% wild-type level of AtCtpA showed normal growth under low light but was stunted and accumulated pD1 under high light, indicative of delayed C-terminal processing. (pnas.org)
  • Generally, the process utilizes wavelengths from about one light second to about ten electron volts, or wavelengths with energy levels less than that of ionization. (google.ca)
  • In particular, the authors analyzed the connection between the changes of photochemical reflectance index and the acidification of the lumen of the chloroplasts exposed to light. (eurekalert.org)
  • Based on the backgrounds, the objective of this study is to (1) examine generations of OH radicals due to a HONO photochemical reaction under different light conditions and (2) examine spatial distributions of products from the chemical reaction between OH radicals and VOCs under varied conditions. (thefreedictionary.com)
  • After three hours the light switches on for around three hours, causing a photochemical reaction which works to kill the cancer, a process known as photodynamic therapy (PDT). (thefreedictionary.com)
  • Elementary process of energy transfer in photosynthetic pigment system. (nii.ac.jp)
  • In addition to the previously described breathing sphere approach developed for simulation of laser ablation/desorption of molecular systems, it includes radiative and nonradiative decay, exciton hopping, two pooling processes, and electron capture. (virginia.edu)
  • Transition metal photocatalysis thus represents a promising strategy towards the development of practical, scalable industrial processes with great environmental benefits. (nature.com)
  • Photoinduced energy and electron transfer processes. (indigo.ca)
  • Union Process, Inc., known globally as a manufacturer of particle size reduction and dispersing equipment, as well as a supplier of grinding media and materials characterization services for a broad range of research and industrial applications, has built a QL100 circulation Attritor for a large automotive accessories supplier. (thomasnet.com)