A new and general procedure is described for a detailed analysis of time-resolved fluorescence depolarisation data in the presence of electronic energy migration. An isotropic ensemble of bifluorophoric molecules (D1-R-D2) has been studied to demonstrate its utility. Intramolecular donor-donor energy migration occurs between the two donor groups (D), which are covalently connected to a rigid linker group (R). These groups undergo restricted reorientational motions with respect to the R group. The analysis of depolarisation data basically involves the search for best-fit parameters which describe the local reorienting motions, the interfluorophore D1-D2 distance, as well as the mutual orientations of the donors. For this, the analysis is partly performed in the Fourier domain and the best-fit parameters are determined by using an approach based on a Genetic Algorithm. The energy migration process has been described by using Monte Carlo simulations and an extended Förster theory. It is found that ...

In this paper, the electrical-to-thermal energy transfer efficiency of the transistor coil ignition system for spark-ignition engines is investigated using both electrical and calorimetry measurements. The gap voltage and discharge current are measured to determine the electrical energy supplied to the spark gap. A pressure-rise calorimeter is used to estimate the thermal energy transferred from the plasma channel to the gas. Firstly, this paper studies the influences of spark gap size, electrode geometry and background pressure on the energy transfer efficiency. To further investigate the effectiveness of increasing breakdown energy on the energy transfer process, a direct-capacitor is paralleled to the spark gap to redistribute the spark energy in both breakdown and glow phases. The varying of the capacitance enables the investigation of the energy transfer efficiency under different breakdown energy level. Results show that the electrical-to-thermal energy transfer efficiency is strongly ...

TY - JOUR. T1 - Femtosecond transient absorption of zinc porphyrins with oligo(phenylethylnyl) linkers in solution and on TiO2 films. AU - Chang, Chih Wei. AU - Luo, Liyang. AU - Chou, Chung Kung. AU - Lo, Chen Fu. AU - Lin, Ching Yao. AU - Hung, Chen Shiung. AU - Lee, Yuan Pern. AU - Diau, Eric Wei Guang. PY - 2009/7/9. Y1 - 2009/7/9. N2 - We measured femtosecond transient absorption of dye solutions and TiO 2 films sensitized with two zinc porphyrins (PE1 and PE4) to investigate the interfacial dynamics of electron transfer in relation to the dependence of cell performance on the length of the linker (Lin, C.-Y.; Lo, C.-F.; Luo, L.; Lu, H.-P.; Hung, C.-S.; Diau, E. W.-G. J. Phys. Chem. C 2009, 113, 755-764). For both porphyrins adsorbed on TiO2 films with S 1 excitation (λex = 620 nm), the transient absorption kinetics probed at 630 nm and 4.9 μm are complementary to each other because only the excited-state and ground-state species were observed at 630 nm whereas only the charge-separation ...

Two recently developed theories of electronic energy transfer/migration were for the first time applied to real protein systems for extracting molecular distances. The partial donor-donor energy migration (PDDEM) is an extension to the previously developed donor-donor energy migration (DDEM, F Bergström et al PNAS 96, 1999, 12477) which allows using chemically identical but photophysically different fluorophores in energy migration experiments. A method based on fluorescence quenching was investigated and applied to create an asymmetric energy migration between fluorophores which were covalently and specifically attached to plasminogen activator inhibitor type 2 (PAI-2). It was also shown experimentally that distance information can be obtained if the fluorescence relaxation for photophysically identical donors, exhibits multi-exponential relaxation.. An extended Förster theory (EFT) that was previously derived (L. B.-Å. Johansson et al J. Chem. Phys., 1996, 105) ha been developed for ...

TY - JOUR. T1 - On the Mechanism of Light Harvesting in Photosynthetic Purple Bacteria. T2 - B800 to B850 Energy Transfer. AU - Scholes, Gregory D.. AU - Fleming, Graham R.. PY - 2000/3/2. Y1 - 2000/3/2. N2 - The rate of energy transfer from B800 to B850 in the peripheral light harvesting complex LH2 is modeled in detail. A method for determining ensemble average energy transfer rates in complex, coupled multichromophoric systems is reported and is employed to investigate the interplay of electron-phonon coupling (fast fluctuations of the protein) and site energy disorder (slow fluctuations) on the spectral overlap between donor and acceptor, and therefore the energy transfer rate. A series of model calculations for Rb. sphaeroides is reported. The disorder is found to have a marked influence on the calculated rate of energy transfer and is responsible for a faster energy transfer time than would occur in its absence and furthermore accounts for the weak temperature dependence observed in ...

Irradiation of crystalline salts formed between sensitizer-linked amines and photochemically reactive carboxylic acids at wavelengths where only the sensitizers absorb leads to characteristic triplet state reactivity of the carboxylate anions. Copyright (C) 1996 Elsevier Science Ltd. ...

A wireless energy transfer system includes a first energy transfer unit having at least one resonant frequency, a second energy transfer unit having the at least one resonant frequency, and a load. The first wireless energy transfer unit includes a first coil magnetically coupled to a first wireless energy transfer cell, and the second wireless energy transfer unit includes a second coil magnetically coupled to a second wireless energy transfer cell. The first coil receives first energy and through the magnetic coupling between the first coil and the first wireless energy transfer cell, the first wireless energy transfer cell is caused to generate second energy, wherein the second wireless energy transfer cell receives the second energy and through the magnetic coupling between the second wireless energy transfer cell and the second coil, the second coil is caused to provide third electromagnetic wave energy to the load.

Previous work using reconstituted membranes has shown that energy transfer can be observed in mixed assemblies of LH2 and RCLH1 complexes,36-38 but controlling the relative stoichiometries and two-dimensional organization of energy donor/acceptor photosynthetic complexes on a nanometer scale, and the locations where excitation energy can migrate between them, presents new challenges. For some time, it has been possible to construct nanoarrays of single types of photosynthetic complex, starting with the light-harvesting LH2 complex of Rba. sphaeroides,18,19,21 and later the RCLH1 complex20 and the LHCII complex of plants.22 In each case the function of the complex, in terms of fluorescence emission, was retained; for LHCII it was possible to directly image the ability of immobilized molecules of LHCII to switch between fluorescent and quenched states. For LH2, there were indications of long-range excitation energy transfer; 80 nm-wide nanolines of LH2 complexes exhibited energy propagation on ...

Photosynthesis: How Proteins Control Excitation Energy Transfer: 10.4018/978-1-60566-076-9.ch034: This chapter introduces the theory of optical spectra and excitation energy transfer of light harvesting complexes in photosynthesis. The light energy

In this work the photophysics of four bichromophoric units was studied by means of static and time resolved spectroscopy, with the aim of disentangling the contribution of steric and electronic factors in regulating the efficiency of electronic energy transfer (EET). The newly synthesized dyads share the same acceptor moiety, a substituted BODIPY chromophore, and differ either in the donor or in the molecular bridge connecting the two units. The use of different linkers allows for tuning the conformational flexibility of the dyad, while changing the donor has an influence on the electronic coupling and spectral overlap between the two chromophores. The efficiency of energy transfer is extremely high in all the four dyads and can be modelled within the frame of the Förster equation. In the special case of a dimeric donor, a theoretical analysis was performed to further support the experimental findings. Geometry optimization at DFT level indicated that different conformations with similar energy ...

Energy Transfer LP (NYSE: ET) today announced a quarterly cash distribution of $0.1525 per ET common unit ($0.61 on an annualized basis) for the first quarter ended March 31, 2021. The announced quarterly distribution is consistent with the distribution for the fourth quarter of 2020 and will be paid on May 19, 2021 to unitholders of record as of the close of business on May 11, 2021.. First Quarter 2021 Earnings Release and Conference Call. In addition, Energy Transfer plans to release earnings for the first quarter 2021 on Thursday, May 6, 2021, after the market closes. The company will conduct a conference call on Thursday, May 6, 2021 at 4:00 p.m. Central Time/5:00 p.m. Eastern Time to discuss quarterly results and provide a company update. The conference call will be broadcast live via an internet webcast, which can be accessed on Energy Transfers website at energytransfer.com. The call will also be available for replay on Energy Transfers website for a limited time.. Energy Transfer LP ...

The development of fluorescent sensors for Hg2+ has attracted much attention due to the well-known adverse effects of mercury on biological health. In the present work, the optical properties of two newly-synthesized Hg2+ chemosensors based on the coumarin-rhodamine system (named Pro1 and Pro2) were systematically investigated using time-dependent density functional theory. It is shown that Pro1 and Pro2 are effective ratiometric fluorescent Hg2+ probes, which recognize Hg2+ by Förster resonance energy transfer and through bond energy transfer mechanisms, respectively. To further understand the mechanisms of the two probes, we have developed an approach to predict the energy transfer rate between the donor and acceptor. Using this approach, it can be inferred that Pro1 has a six times higher energy transfer rate than Pro2. Thus the influence of spacer group between the donor and acceptor on the sensing performance of the probe is demonstrated. Specifically, two-photon absorption properties of these two

Artificial Light-Harvesting Arrays: Electronic Energy Migration and Trapping on a Sphere and between Spheres A sophisticated model of the natural light-harvesting antenna has been devised by decorating a C60 hexa-adduct with ten yellow and two blue boron dipyrromethene (Bodipy) dyes in such a way that the dyes retain their individuality and assist solubility of the fullerene. Unusually, the fullerene core is a poor electron acceptor and does not enter into light-induced electron-transfer reactions with the appended dyes, but ineffective electronic energy transfer from the excited-state dye to the C60 residue competes with fluorescence from the yellow dye. Intraparticle electronic energy transfer from yellow to blue dyes can be followed by steady-state and time-resolved fluorescence spectroscopy and by excitation spectra for isolated C60 nanoparticles dissolved in dioxane at 293 K and at 77 K. Full article ...

Inteins as Traceless Purification Tags for Unnatural Amino Acid Proteins. Batjargal, S.; Walters, C. R.; Petersson, E. J.. J. Am. Chem. Soc. 2015, 137, 1734-1737.. Specific Modulation of Protein Activity Through a Bioorthogonal Reaction. Warner, J. B.; Muthusamy, A. K.; Petersson, E. J.. ChemBioChem 2014, 24, 2508-2514.. Thioamide-Based Fluorescent Protease Sensors. Goldberg, J. M.; Chen, X. S.; Meinhardt, N.; Greenbaum, D. C.; Petersson, E. J. J. Am. Chem. Soc. 2014, 136, 2086-2093.. Efficient Synthesis and In Vivo Incorporation of Acridonylalanine, a Fluorescent Amino Acid for Lifetime and Förster Resonance Energy Transfer/Luminescence Resonance Energy Transfer Studies Speight, L. C.; Muthusamy, A. K.; Goldberg, J. M.; Warner, J. B.; Wissner, R. F.; Willi, T.; Woodman, B.; Mehl, R. A.; Petersson, E. J. J. Am. Chem. Soc. 2013, 135, 18806-18814.. Expressed Protein Ligation at Methionine: N-terminal Attachment of Homocysteine, Ligation, and Masking. Tanaka, T.; Wagner, A. M.; Warner, J. B.; ...

China Dts-2L Series Three Phase Electronic Energy Meter, Find details about China Kwh Meter, Energy Meter from Dts-2L Series Three Phase Electronic Energy Meter - Yueqing Tainihan Electrical Technology Co., Ltd.

In this work we report the study of energy transfer between Nd3+ and Yb3+ ions in glasses with the 0.8CaSiO3-0.2Ca3(PO4)2 eutectic composition at room temperature by using steady-state and time-resolved laser spectroscopy. The Nd3+→Yb3+ transfer efficiency obtained from the Nd3+ lifetimes in the single doped and codoped samples reaches 73% for the highest Nd3+ concentration. The donor decay curves obtained under pulsed excitation have been used to establish the multipolar nature of the Nd3+→ Yb3+ transfer process and the energy transfer microparameter. The nonradiative energy transfer is consistent with an electric dipole-dipole interaction mechanism assisted by energy migration among donors. Back transfer from Yb3+ to Nd3+ is also observed.. ©2010 Optical Society of America. Full Article , PDF Article ...

Luminescence of Ce3+ in the hydrogen peroxide induced sulfuric acid solutions was observed to be quenched by Ce4+ ions in the solution by energy transfer due to electric dipole interaction between Ce3+ and Ce4+. A systematic investigation of the energy transfer characteristics of Ce3+-Ce4+ mixture has been made by measuring the absorption, luminescence and excitation spectra at room temperature. The effect, of the concentration of Ce3+ on the energy transfer process has been also studied and the critical transfer distance (R-o) has been calculated considering Forster type interaction between the ions and found to be 8.7 Angstrom for the mixture of 1 x 10(-4) mol l(-1) Ce3+ and 3 x 10(-4) mol l(-1) Ce4+. (C) 2000 Elsevier Science B.V. All rights reserved. ...

Absorption of ultraviolet light by DNA is known to lead to carcinogenic mutations, but the processes between photon absorption and the photochemical reactions are poorly understood. In their study of the excited-stated dynamics of model DNA helices using femtosecond transient absorption spectroscopy1, Crespo-Hernández et al. observe that the picosecond component of the transient signals recorded for the adenine-thymine oligonucleotide (dA)18•(dT)18 is close to that for (dA)18, but quite different from that for (dAdT)9•(dAdT)9; from this observation, they conclude that excimer formation limits excitation energy to one strand at a time. Here we use timeresolved fluorescence spectroscopy to probe the excited-state dynamics, which reveals the complexity of these systems and indicates that the interpretation of Crespo-Hernández et al. is an oversimplification. We also comment on the pertinence of separating base stacking and base pairing in excited-state dynamics of double helices and question the

Donor-bridge-acceptor triads consisting of the Alq3 complex, oligofluorene bridge, and PtII tetraphenylporphyrin (PtTPP) were synthesized. The triads were designed to study the energy level/distance-dependence in energy transfer both in a solution and in solid state. The materials show effective singlet transfer from the Alq3-fluorene fluorophore to the porphyrin, while the triplet energy transfer, owing to the shorter delocalization of triplet excitons, appears to take place via a triplet energy cascade. Using femtosecond transient spectroscopy, the rate of the singlet−singlet energy transfer was determined. The exponential dependence of the donor−acceptor distance and the respective energy transfer rates of 7.1 × 1010 to 1.0 × 109 s-1 with the attenuation factor â of 0.21 ± 0.02 Å-1 suggest that the energy transfer proceeds via a mixed incohererent wire/superexchange mechanism. In the OLEDs fabricated using the Alq3-oligofluorene-PtTPP triads with better triplet level alignment, the order of

Since the triplet-triplet annihilated upconversion (TTA-UC) materials work efficiently only in degassing organic solvents, it is of significance to find a new medium without toxicity and volatility and that promotes TTA-UC. Here, we firstly reported the effect of an OH-containing medium on low power upconver

The conservative and dissipative dynamics of a 2DOF, system composed of a grounded linear oscillator coupled to a lightweight mass by means of both strongly nonlinear and linear negative stiffnesses is investigated. Numerical studies are presented aiming to assess the influence of this combined coupling on the transient dynamics. In particular, these studies are focused on passive nonlinear targeted energy transfer from the impulsively excited linear oscillator to the nonlinear bistable lightweight attachment. It is shown that the main feature of the proposed configuration is the ability of assuring broadband efficient energy transfer over a broad range of input energy. Due to the bistability of the attachment, such favorable behavior is triggered by different nonlinear dynamic mechanisms depending on the energy level. For high energy levels, strongly modulated oscillations occur, and the dynamics is governed by fundamental (1:1) and superharmonic (1:3) resonances; for low energy levels, chaotic ...

Femtosecond transient absorption spectrometer Our femtosecond transient absorption spectrometer is a homemade pump-continuum-probe setup. The main femtosecond laser source is a Ti:Sapphire system from Spectra-Physics (Tsunami oscillator followed by a Spitfire regenerative amplifier). It delivers 50-fs ~0.7 mJ pulses at 1 kHz around 800 nm. Tunable pump pulses in the visible are produced by a noncollinear optical parametric amplifier (NOPA, Clark-MXR). A broadband continuum probe is obtained by self-phase modulation of a 800-nm beam in a CaF2 plate. Its time delay with respect to the pump is adjusted in a motorized optical delay line. The pump and probe beams are focused with parabolic mirrors and overlapped in the sample, kept in a 1-mm cell. The sample may be constantly displaced in two directions to avoid the re-excitation of a previously excited area. The sample may also be thermostated with the help of a water bath circulated through the sample holder. Fig 1 gives a schematic view of the ...

UNSPECIFIED (1989) MECHANISM OF ENERGY-TRANSFER IN COLLISIONAL ACTIVATION OF KILOELECTRON-VOLT MACROMOLECULAR IONS. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, 44 (3). pp. 245-246 ...

i) Photosynthetic organisms are exquisitely arranged so as to capture incident sunlight with high efficacy, and transmit the transient excitation energy to a reaction centre where chemical reactions are initiated. The energy-transfer mechanism is often described by semi-classical models that invoke hopping of the wave-packet along discrete energy levels and over considerable distances set in 3-dimensional space. These energy levels combine to form a large peripheral light-harvesting antenna coupled to individual reaction centres. Many attempts have been made to duplicate the essential features of the natural process, ignoring elaborate events such as self-repair and quantum coherence, and great progress has been made in understanding the basic energy-transfer steps. Mostly, these bio-inspired molecular systems have been studied as standalone entities in 2-dimensions, with little consideration given to longer-range energy transfer between moieties embedded in a solid matrix. We have built and ...

In the design of transcutaneous energy transfer devices variation in spacing between the coils results in energy transfer efficiency changes. These changes may have other causes. It is proposed to use an autotuning circuit and a voltage control circuit in cooperation with feedback from the internal coil in order to better maintain energy transfer levels as desirable. The feedback is typically provided via IR communication; however, when skin is highly pigmented, IR communication is inefficient. A method and system for using RF signals to accomplish the communication is disclosed.

Bypassing the energy functional in density functional theory: Direct calculation of electronic energies from conditional probability ...

The method of orthogonalized plane waves is applied to a calculation of electronic energy levels in potassium, using a potential obtained from a self-consistent field. The energies of twenty-four states at four symmetry points in the Brillouin zone have been obtained. The lowest band is dismissed in detail and the qualitative features of the density of states are presented. Departures from free electron bands are found. Comparison of higher bands with some other calculations suggests that certain features of band schemes may be reasonably independent of the potential used.

This thesis describes studies of collisional energy transfer in two small, combustion relevant free radicals. Collision-induced electronic energy transfer (EET) between the B2r and A2 fj. states of the CH and CD radicals was investigated with the collision partners He, Ar, H2, N2, CO and C02 using a dispersed laser induced fluorescence technique. CH or CD radicals were prepared photolytically, and excited into a single rotational level in either of the B2::E-, v ==°or A211, v =1 levels. Wavelength dispersed, time-resolved emission was then recorded from the initial and product states. Microscopic rate constants for vibronically resolved transfer between the two electronic states were determined for each collision partner, as well as those for vibrational energy transfer in the A state and total removal to other, unobserved states. EET was demonstrated to be ubiquitous, occurring with all of the collision partners used in the study, with varying efficiencies. These relative efficiencies ...

OppenheimerFunds Inc. raised its position in Energy Transfer Equity, L.P.by 4.3% in the first quarter.. 05/10/2017 - ENERGY TRANSFER PARTNERS was upgraded to by analysts at Sanford C. Bernstein. The stock of Energy Transfer Partners LP (NYSE:ETP) has Buy rating given on Tuesday, August 11 by Stifel Nicolaus. Goldman Sachs maintained it with Neutral rating and $17 target in Wednesday, July 13 report. Finally, ValuEngine lowered shares of Energy Transfer Equity, L.P. from a buy rating to a hold rating in a research report on Friday, June 2nd. The firm has Outperform rating given on Wednesday, May 10 by Bernstein. They set a buy rating and a $20.00 price target on the stock. One research analyst has rated the stock with a sell rating, seven have assigned a hold rating, ten have issued a buy rating and one has issued a strong buy rating to the companys stock.. Global X Management Co Llc decreased its stake in Yandex N V (YNDX) by 22.57% based on its latest 2016Q4 regulatory filing with ...

It was once purported that biological systems were far too warm and wet to support quantum phenomena mainly owing to thermal effects disrupting quantum coherence. However, recent experimental results and theoretical analyses have shown that thermal energy may assist, rather than disrupt, quantum coherent transport, especially in the dry hydrophobic interiors of biomolecules. Specifically, evidence has been accumulating for the necessary involvement of quantum coherent energy transfer between uniquely arranged chromophores in light harvesting photosynthetic complexes. The tubulin subunit proteins, which comprise microtubules, also possess a distinct architecture of chromophores, namely aromatic amino acids, including tryptophan. The geometry and dipolar properties of these aromatics are similar to those found in photosynthetic units indicating that tubulin may support coherent energy transfer. Tubulin aggregated into microtubule geometric lattices may support such energy transfer, which could be

Where j is the jth range of intensity, m is the number of pixel in a and d, n is the number of pixel in e and g, DSBTi is the donor bleed-through of the pixel (i) in f, ai is the intensity of pixel i, so is bi, and ei, k is the number of range, DSBT is the total donor bleed-through, ASBTi is the acceptor bleed-through of the pixel (i) in f, ci is the intensity of pixel i, so is di, and gi.k is the number of range, ASBT is the total acceptor bleed-through.. The precision FRET (PFRET) is calculated using following equation where uFRET represents uncorrected FRET which is image f:. PFRET=uFRET-DSBT-ASBT. Energy transfer efficiency (E). Conventionally, energy transfer efficiency (E) is calculated by ratioing the donor image in the presence (IDA) and absence (ID) of acceptor. When using the algorithm as described, we indirectly obtained the ID image by using the PFRET image (Elangovan et al., 2003). ID=IDA+PFRET where IDA is image e. The efficiency calculation is shown in following ...

Methods and apparatus for providing a sufficiently stable power to a load in an energy transfer system that transfers energy from one side of a physical boundary to another side of he boundary. In one example, a power supply and a primary winding are located on a first side of a physical boundary (e.g., external to a body), and a secondary winding and the load are located on a second side of the physical boundary (e.g., internal to the body). A primary voltage across the primary winding is regulated so as to provide a sufficiently stable output power to the load notwithstanding changes in the load and/or changes in a relative position of the primary winding and the secondary winding. One aspect of the invention relates to energy transfer methods and apparatus for use in connection with the human body. In particular, one example of the invention includes a transcutaneous energy transfer (TET) system for transferring power from a power supply external to the body to a device implanted in the body.

From Dynamic Equilibrium to Photoinitiated Processes: Tracking Condensed Phase Dynamics. Abstract. Many important processes in chemistry and biology occur in the solution phase, including protein conformation changes, energy transfer processes, and proton and electron transfer reactions. Understanding condensed phase dynamics is essential for describing and predicting these processes, which is why it is a prevailing topic throughout the scientific community. In this talk I will discuss two different research topics that explore different processes in condensed phase systems. The first focuses on understanding ultrafast photoinitiated processes of photosystem I, a light harvesting complex that catalyzes oxygenic photosynthesis. Here two- dimensional electronic spectroscopy (2DES) gives remarkable insight into the very first steps of light harvesting in photosynthesis. The second explores dynamic equilibrium in a fluxional metal-carbonyl complex. Here two-dimensional infrared (2DIR) spectroscopy ...

Fluorescent labels are provided employing energy absorber/donor components and energy acceptor/fluorescer components joined together by a spacer which comprises sugar phosphate monomeric units, particularly ribosyl phosphate monomeric units, where the sugar groups are free of active hydroxyl groups. Particularly, an energy transfer component is substituted at the 5 position of the spacer chain, while the other energy transfer component is substituted at the 1 position of the 3 terminal ribosyl group of the label forming an ET cassette for linking to a nucleic acid sequence with any compositions. By employing combinations of ET components, with a common energy absorber/donor and different fluorescers, one can provide for families of labels which can be tagged to any target molecules and which can be excited at a single wavelength and fluoresce at different wavelengths with large Stokes shifts. The compositions find particular application in sequencing.

The institutional sentiment decreased to 0.7 in Q2 2015. Its down 0.32, from 1.02 in 2015Q2. The ratio dived, as 78 funds sold all their Energy Transfer Equity LP shares they owned while 123 reduced their positions. 28 funds bought stakes while 112 increased their total positions. Institutions now own 1.02 billion shares which is 305.12% more than the previous share count of 251.55 million in 2015Q2.. Walnut Private Equity Partners Llc holds 21.12% of its total portfolio in Energy Transfer Equity LP, equating to 1.20 million shares. Yorkville Capital Management Llc owns 863,918 shares representing 17.95% of their total US portfolio. Moreover, C V Starr & Co Inc has 12.12% of their total portfolio invested in the company, equating to 110,230 shares. The Kansas-based Whetstone Capital Advisors Llc has a total of 10.07% of their portfolio invested in the stock. Heronetta Management L.P., a New York-based fund reported 638,780 shares owned.. Energy Transfer Equity, L.P. is a limited partnership ...

View stock charts, earnings and estimates(fiscal report), company news, insider tradings, outstading shares and analysis on ENERGY TRANSFER PARTNERS(NYSE:ETP) at Valinv.com.

Watson, I.M. and Heliotis, G. and Itskos, G. and Lagoudakis, P.G. and Feldmann, J. and Murray, R. and Bradley, D.D.C. and Dawson, M.D. (2006) Non-radiative energy transfer in hybrid structures combining InGaN single QWs and light-emitting polymers. In: 6th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED 2006), 2006-05-15 - 2006-05-19. (Unpublished) Full text not available in this repository.Request a copy from the Strathclyde author ...

TY - JOUR. T1 - Energy transfer in the azobenzene-naphthalene light harvesting system. AU - Abdallah, Dalia. AU - Whelan, Jamie. AU - Dust, Julian M.. AU - Hoz, Shmaryahu. AU - Buncel, Erwin. PY - 2009/6/18. Y1 - 2009/6/18. N2 - We have investigated the model light harvesting systems (LHSs) A and B typifying energy transfer (ET) between a naphthalene, Np (donor, D), and an azobenzene, Az (acceptor, A), shown schematically in Scheme 2. These models were actualized as the naphthyl azo molecules 1 and 4 containing a methylene tether (Scheme 1). The methoxy azo molecules 2 and 5, respectively, served as benchmarks for the assessment of ET. Photophysical data, including initial rate constants for photoisomerization (trans to cis, t-1 →c-1, and cis to trans, c-1 →t-1), the relevant c-1 →t-1 quantum yields, and fluorescence quenching with free naphthalene, 3, as D were measured. Therefore, (1) irradiation of 3 at (270 nm) to give 3* generates fluorescence at 340 nm that is 65% quenched by the ...

6H, please click HERE for all of our daily lesson plans in Science.. Energy can be transferred from one form to another. Sometimes we want to transfer energy in a useful way, but other times we want to prefer to prevent energy transfer.. ...

This patent search tool allows you not only to search the PCT database of about 2 million International Applications but also the worldwide patent collections. This search facility features: flexible search syntax; automatic word stemming and relevance ranking; as well as graphical results.

Tesla has a large office in Draper, Utah that it inherited from its acquisition of SolarCity.. Therefore, many of the employees work for Teslas energy division, but it also expended to other operations and customer support roles. Hundreds of Tesla employees now work at the location.. Earlier today, we received tips from employees saying that Tesla was mass-firing people and several people took to social media with similar claims affecting Teslas energy division.. We have reached out to Tesla for a comment on the situation and the company said that it is only transferring its energy support division from Utah in order to centralize it.. A Tesla spokesperson sent us the following comment:. ...

1. (1)中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室，武汉 430071; (2)中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室，武汉 430071;中国科学院安徽光学精密机械研究所激光光谱学开放实验室，合肥 ...

Abstract: According to the theory of quantum electrodynamics, transfer of electronic energy between molecules occurs through the exchange of photons. The nature of energy transfer is highly dependent on distances between molecular centres involved in the transfer process. At short distances photons have a virtual character and molecules are coupled by longitudinal as well as transverse components of the field (with an $ R^{-3} $ dependence on the coupling). As the distance of separation increases, photons take on a more real character and coupling is dominated by transverse components of the field (in the far-zone limit the coupling has the usual Columbic $ R^{-1} $ dependence on separation). Of particular interest is the intermediate- zone where the distance separating the molecular centres is approximately equal to the reduced wavelength of the mediating photon. In this regime, electronic coupling has a separation dependence of $ R^{-2} $.. After a brief introduction to electronic energy ...

A series of single-phased emission-tunable Na0.34Ca0.66Al1.66Si2.34O8:Eu2+,Mn2+ phosphors were successfully synthesized by a wet-chemical synthesis method. Photoluminescence excitation (PLE) spectra indicate that the phosphor can be efficiently excited by UV radiation from 250 to 420 nm. Also, NCASO:Eu2+,Mn2+ phosphor exhibit a broad blue emission band at 440 nm and an orange emission band at 570 nm, which originate from Eu2+ and Mn2+ ions, respectively. Therefore, overall emission color can be tuned from blue to white by increasing the concentration of Mn2+ ions in the host lattice utilizing energy transfer from Eu2+ to Mn2+ ions. This energy transfer phenomenon was demonstrated to be a resonant type through dipole-dipole interaction determined with the help of PL spectra, decay time measurement, and energy transfer efficiency of the phosphor. These results indicate that NCASO:Eu2+,Mn2+ can be a promising single-phased white-emitting phosphor for white-light UV LEDs.. ©2013 Optical Society of ...

The ability to convert between molecular spin states is of utmost importance in materials chemistry. Förster-type energy transfer is based on dipole-dipole interactions and can therefore theoretically be used to convert between molecular spin states. Here, a molecular dyad that is capable of transferring energy from an excited triplet state to an excited singlet state is presented. The rate of conversion between these states was shown to be 36 times faster than the rate of emission from the isolated triplet state. This dyad provides the first solid proof that Förster-type triplet-to-singlet energy transfer is possible, revealing a method to increase the rate of light extraction from excited triplet states. ...

An apparatus is disclosed for exothermically obtaining hydrogen or hydrogen peroxide from water vapor in a reaction chamber. The separation of the hydrogen and oxygen may be accelerated through the use of a combination host and sensitizer material which is present near spaces or voids within the reaction chamber. The water vapor has certain particular absorption bands in its absorption versus frequency characteristic. Each of the sensitizers which are located adjacent the voids in the reactant, in one embodiment forming part of the walls of small cylindrical tubes, has an energy output in the excited state which is precisely in one of the energy absorption bands in the water vapor characteristic. The host material absorbs heat energy and excites the sensitizer material. In addition to the formation of free hydrogen, some hydrogen peroxide is also formed. Other feedstocks may have energy selectively applied to them.Alternative appparatus for applying high intensity radiation to feedstock include (1) a

The principle of energy transfer is a major proposition in the interaction between energy-producing and energy-utilizing pathways in living and thriving cells. Energy transfer from one organism to another is part of the law of conservation of energy.. ...

Energy Transfer Partners, L.P. (NYSE: ETP) today announced that its wholly owned subsidiaries, Energy Transfer Interstate Holdings, LLC (

TY - JOUR. T1 - Excitation energy transfer between dye molecules in lasing microparticles. AU - Takahashi, T.. AU - Fujiwara, K.. AU - Matsuo, S.. AU - Misawa, H.. N1 - Funding Information: The present work was partly supported by the Satellite Venture Business Laboratory of the University of Tokushima. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.. PY - 1999/1/18. Y1 - 1999/1/18. N2 - Energy transfer from excited state donor to ground state acceptor dyes in polymer microparticles with a diameter of 30-60 μm was observed under lasing condition. The energy transfer efficiency was found to be higher with the increasing size of the particle. This result indicates that the excitation energy transfer efficiency can be controlled by the particle size without varying temperature and dye concentration. The dynamics of energy transfer was observed through picosecond time-resolved emission spectral measurements.. AB - Energy transfer from excited state donor to ground state acceptor dyes ...

Double loading of a zeolite with a triplet energy donor and a triplet energy acceptor followed by selective irradiation into the donor absorption band leads to characteristic triplet state reactivity of the acceptor.. ...

During photosynthesis, sunlight is efficiently captured by light-harvesting complexes, and the excitation energy is then funneled towards the reaction centre. These photosynthetic excitation energy transfer (EET) pathways are complex and proceed in a multistep fashion. Ultrafast two-dimensional electronic spectroscopy (2DES) is an important tool to study EET processes in photosynthetic complexes. However, the multistep EET processes can only be indirectly inferred by correlating different cross peaks from a series of 2DES spectra. Here we directly observe multistep EET processes in LHCII using ultrafast fifth-order three-dimensional electronic spectroscopy (3DES). We measure cross peaks in 3DES spectra of LHCII that directly indicate energy transfer from excitons in the chlorophyll b (Chl b) manifold to the low-energy level chlorophyll a (Chl a) via mid-level Chl a energy states. This new spectroscopic technique allows scientists to move a step towards mapping the complete complex EET processes ...

TY - JOUR. T1 - Efficient estimation of energy transfer efficiency in light-harvesting complexes. AU - Shabani, A.. AU - Mohseni, M.. AU - Rabitz, H.. AU - Lloyd, S.. N1 - Copyright: Copyright 2012 Elsevier B.V., All rights reserved.. PY - 2012/7/17. Y1 - 2012/7/17. N2 - The fundamental physical mechanisms of energy transfer in photosynthetic complexes is not yet fully understood. In particular, the degree of efficiency or sensitivity of these systems for energy transfer is not known given their realistic with surrounding photonic and phononic environments. One major problem in studying light-harvesting complexes has been the lack of an efficient method for simulation of their dynamics in biological environments. To this end, here we revisit the second order time-convolution (TC2) master equation and examine its reliability beyond extreme Markovian and perturbative limits. In particular, we present a derivation of TC2 without making the usual weak system-bath coupling assumption. Using this ...

0008]Strand specific methods utilise additional nucleic acid reaction components to monitor the progress of amplification reactions. These methods may use fluorescence energy transfer (PET) as the basis of detection. One or more nucleic acid probes are labelled with fluorescent molecules, one of which is able to act as an energy donor and the other of which is an energy acceptor molecule. These are sometimes known as a reporter molecule and a quencher molecule respectively. The donor molecule is excited with a specific wavelength of light for which it will normally exhibit a fluorescence emission wavelength. The acceptor molecule is also excited at this wavelength such that it can accept the emission energy of the donor molecule by a variety of distance-dependent energy transfer mechanisms. A specific example of fluorescence energy transfer which can occur is Fluorescence Resonance Energy Transfer or FRET. Generally the acceptor molecule accepts the mission energy of the donor molecule when ...

HU, a multi-functional DNA-binding protein, acts primarily as an architectural protein. The proposed function of HU is stabilization of DNA in a bent conformation or bending of duplex DNA to allow access for other proteins to bind to the DNA and carry

We have studied the influence of the local density of optical states (LDOS) on the rate and efficiency of Förster resonance energy transfer (FRET) from a donor to an acceptor. The donors and acceptors are dye molecules that are separated by a short strand of double-stranded DNA. The LDOS is controlled by carefully positioning the FRET pairs near a mirror. We find that the energy transfer efficiency changes with LDOS, and that, in agreement with theory, the energy transfer rate is independent of the LDOS, which allows one to quantitatively control FRET systems in a new way. Our results imply a change in the characteristic Förster distance, in contrast to common lore that this distance is fixed for a given FRET pair.. ...

Solar power production and solar energy storage are important research areas for development of technologies that can facilitate a transition to a future society independent of fossil fuel based energy sources. Devices for direct conversion of solar photons suffer from poor efficiencies due to spectrum losses, which are caused by energy mismatch between the optical absorption of the devices and the broadband irradiation provided by the sun. In this context, photon-upconversion technologies are becoming increasingly interesting since they might offer an efficient way of converting low energy solar energy photons into higher energy photons, ideal for solar power production and solar energy storage. This perspective discusses recent progress in triplet-triplet annihilation (TTA) photon-upconversion systems and devices for solar energy applications. Furthermore, challenges with evaluation of the efficiency of TTA-photon-upconversion systems are discussed and a general approach for evaluation and comparison

Fluorescence Resonance Energy Transfer (FRET) is an energy transfer process between the fluorescent dye molecules [1]. Due to its high sensitivity to the change of distance between the dyes, it has received great interest for the study of biological systems [2]. FRET technique has a spatial resolution of sub-nanometer, and can be used as a probe of inter- and intra-molecular dynamics of biological macromolecules such as protein conformational change, enzyme-substrate reaction, and RNA folding [3][4]. Determination of FRET efficiency in ensemble measurement is, however, not straightforward due to the difficulty in distinguishing FRET pairs from unpaired dyes or the dyes not properly labeled to the bio-molecule in question that might give huge background [5]. By contrast, single-molecule detection provides a method that is free from this obstacle as it can only collect the signal from one single FRET pair. Another advantage of this technique is that it allows monitoring the structural- or ...

This dissertation describes the observed interactions between energy transfer in small clusters of nominally monodisperse semiconductor nanocrystals (quantum dots, QDs) and single molecule phenomena such as fluorescence intermittency (blinking) and antibunching. The relevant literature on energy transfer between QDs has typically invoked the Förster energy transfer mechanism to explain the observations in ensemble measurements. The size dispersion in QDs results in a dispersion in the electronic and optical properties of QDs due to size dependent confinement effects on photogenerated carriers ...

Compartmentalization of high-energy phosphate carriers between intracellular micro-compartments is a phenomenon that ensures efficient energy use. To connect these sites, creatine kinase (CK) and adenylate kinase (AK) energy-transfer networks, which are functionally coupled to oxidative phosphorylation (OXPHOS), could serve as important regulators of cellular energy fluxes. Here, we introduce how selective permeabilization of cellular outer membrane and high-resolution respirometry can be used to study functional coupling between CK or AK pathways and OXPHOS in different cells and tissues. Using the protocols presented here the ability of creatine or adenosine monophosphate to stimulate OXPHOS through CK and AK reactions, respectively, is easily observable and quantifiable. Additionally, functional coupling between hexokinase and mitochondria can be investigated by monitoring the effect of glucose on respiration. Taken together, high-resolution respirometry in combination with permeabilization is a

Since Kaiser and Garretts pioneering work on two-photon absorption 40 years ago, observations of blue-shifted fluorescence have been widely used as a marker and measure of non-linear excitation. In doped crystals or in molecular multi-chromophore systems, where resonance energy transfer conveys excitation from the sites of initial photoabsorption to others which yield the fluorescence, this process can play a possible intermediary role in the generation of two-photon fluorescence. Recent work has revealed other competing mechanisms, involving energy transfer between three fluorophore sites, that should be equally or more significant in strongly pumped systems depending on the conditions. It is the purpose of this paper to identify fully the characteristics of one such process involving the coupling of fluorescence energy transfer with Raman emission, and to determine the precise nature of the conditions under which it may be observed.. ...

TY - JOUR. T1 - Unique ultrafast energy transfer in a series of phenylene-bridged subporphyrin-porphyrin hybrids. AU - Oh, Juwon. AU - Sung, Jooyoung. AU - Kitano, Masaaki. AU - Inokuma, Yasuhide. AU - Osuka, Atsuhiro. AU - Kim, Dongho. PY - 2014/9/18. Y1 - 2014/9/18. N2 - A series of phenylene-bridged subporphyrin-Zn(ii) porphyrin (SubP-ZnP) hybrid systems undergo extraordinarily fast excitation energy transfer (EET) processes from the SubP to the ZnP, aided by conjugative electronic elongation of the SubP to the phenylene-bridge. This journal is. AB - A series of phenylene-bridged subporphyrin-Zn(ii) porphyrin (SubP-ZnP) hybrid systems undergo extraordinarily fast excitation energy transfer (EET) processes from the SubP to the ZnP, aided by conjugative electronic elongation of the SubP to the phenylene-bridge. This journal is. UR - http://www.scopus.com/inward/record.url?scp=84906258454&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=84906258454&partnerID=8YFLogxK. U2 - ...

Fleming has compared 2-D electronic spectroscopy to the technique used in the early super-heterodyne radios, where an incoming high frequency radio signal was converted by an oscillator to a lower frequency for more controllable amplification and better reception. In the case of 2-D electronic spectroscopy, scientists can track the transfer of energy between molecules that are coupled (connected) through their electronic and vibrational states in any photoactive system, macromolecular assembly or nanostructure.. Fleming and his group first described 2-D electronic spectroscopy in a 2005 Nature paper, when they used the technique to observe electronic couplings in the Fenna-Matthews-Olson (FMO) photosynthetic light-harvesting protein, a molecular complex in green sulphur bacteria. Said Engel, The 2005 paper was the first biological application of this technique, now we have used 2-D electronic spectroscopy to discover a new phenomenon in photosynthetic systems. While the possibility that ...

TY - JOUR. T1 - Photoluminescence from donor-acceptor molecular systems via long distance energy transfer mediated by surface plasmons. AU - Shimada, Takayuki. AU - Tomita, Satoshi. AU - Hotta, Shu. AU - Hayashi, Shinji. AU - Yanagi, Hisao. PY - 2009/4/1. Y1 - 2009/4/1. N2 - We have studied the energy transfer from p-sexiphenyl (p-6P) to 5,5′-bis(4-biphenylyl)-2,2′-bithiophene (BP2T) mediated by surface plasmons (SPs) on a thin silver layer sandwiched between two MgF2 spacers. The SP-mediated fluorescence of the BP2T acceptor is observed at the donor-acceptor distance beyond 200 nm, which is much longer than the Förster distance. The photoluminescence of BP2T is maximized at silver thickness of roughly 40 nm, where the silver layer is transformed from segregated nanoparticles into a continuous film, at an MgF2 thickness of 10.5 to 52.5 nm.. AB - We have studied the energy transfer from p-sexiphenyl (p-6P) to 5,5′-bis(4-biphenylyl)-2,2′-bithiophene (BP2T) mediated by surface plasmons ...

The thermodynamic phase behavior and lateral lipid membrane organization of unilamellar vesicles made from mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2 distearoyl-sn-glycero-3-phosphocholine (DSPC) were investigated by fluorescence resonance energy transfer (FRET) as a function of temperature and composition. This was done by incorporating a headgroup-labeled lipid donor (NBD-DPPE) and acceptor (N-Rh-DPPE) in low concentrations into the binary mixtures. Two instances of increased energy transfer efficiency were observed close to the phase lines in the DMPC/DSPC phase diagram. The increase in energy transfer efficiency was attributed to a differential preference of the probes for dynamic and fluctuating gel/fluid coexisting phases. This differential preference causes the probes to segregate (S. Pedersen, K. Jørgensen, T. R. Baekmark, and O. G. Mouritsen, 1996, Biophys. J. 71:554-560). The observed increases in energy transfer match with the boundaries of the DMPC/DSPC ...

TY - JOUR. T1 - Two dimensional electronic spectroscopy of molecular complexes. AU - Cho, Minhaeng. AU - Brixner, Tobias. AU - Stiopkin, Igor. AU - Vaswani, Harsha. AU - Fleming, Graham R.. PY - 2006/2. Y1 - 2006/2. N2 - Two dimensional (2D) heterodyne-detected electronic photon echo spectroscopy is introduced and described. We give an intuitive description of the origin and information content of 2D electronic spectra, focusing on molecular complexes. We identify two important quantities-the transition dipole term, and the transition frequency cross correlation function that controls the appearance of 2D electronic spectra. We also show how the transition frequency cross correlation function controls the rate of exciton relaxation. These concepts are illustrated with experimental data on the seven bacteriochlorophyll FMO complex of a green sulfur bacterium, showing how the pathways and mechanisms of energy flow can be elucidated by combining 2D spectra with theoretical modeling.. AB - Two ...

TY - JOUR. T1 - Switching of the inter-component photoinduced electron- and energy-transfer properties of a Ru(II)-azacrown-Re(I) complex; effects of changing temperature, and of incorporation of Ba2+ ion into the macrocyclic spacer between the chromophores. AU - Encinas, S. AU - Bushell, KL. AU - Couchman, SM. AU - Jeffery, JC. AU - Ward, MD. AU - Flamigni, L. AU - Barigelletti, F. PY - 2000. Y1 - 2000. M3 - Article (Academic Journal). SP - 1783. EP - 1792. JO - Dalton. JF - Dalton. SN - 1470-479X. ER - ...

Femtochemistry IX: Femtochemistry, Femtobiology, and Femtophysics - Frontries in Ultrafast Science and Technology, Beijing, China, 8-13 August 2009, p. 111 P-43 ...

TY - CHAP. T1 - Light harvesting, excitation energy/electron transfer, and photoregulation in artificial photosynthetic systems. AU - Terazono, Yuichi. AU - Moore, Thomas A. AU - Moore, Ana L. AU - Gust, John Devens. PY - 2012/1/1. Y1 - 2012/1/1. N2 - This chapter summarizes recent research from our laboratory on multichromophoric molecules that perform as components of artificial photosynthetic systems. The basic scientific principles underlying the design of these molecules were drawn from natural photosynthetic energy conversion, but thematerials used to prepare them are synthetic. The systems consist of chromophores and electron and energy donors and acceptors that have been chemically linked to form artificial reaction centers and antennas, and to mimic some aspects of photosynthetic regulation and photoprotection. These chromophores include porphyrins, fullerenes, carotenoid polyenes, antenna moieties, and photochromic materials. We begin with an introduction to artificial photosynthesis ...

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Vibrational and electronic transition dipole strengths are often good probes of molecular structures, especially in excitonically coupled systems of chromophores. One cannot determine transition dipole strengths using linear spectroscopy unless the concentration is known, which in many cases it is not. In this paper, we report a simple method for measuring transition dipole moments from linear absorption and 2D IR spectra that does not require knowledge of concentrations. Our method is tested on several model compounds and applied to the amide I band of a polypeptide in its random coil andα-helical conformation as modulated by the solution temperature. It is often difficult to confidently assign polypeptide and protein secondary structures to random coil or α-helix by linear spectroscopy alone, because they absorb in the same frequency range. We find that the transition dipole strength of the random coil state is 0.12 ± 0.013 D^2, which is similar to a single peptide unit, indicating that ...

The rate parameters of solvent-solute energy transfer and of oxygen-solvent quenching have been determined for solutions of 2, 5-diphenyloxazole in benzene, toluene, p-xylene and mesitylene. The role of excited molecules and excimers in transfer to the solute molecules is considered in terms of the Voltz relations, which include the Förster critical transfer distance, the molecular diffusion coefficients, and the solvent excitation migration coefficient. It is proposed that the migration is due to excimer formation and dissociation, and that the energy transfer occurs by a diffusion/migration-controlled collisional process. Dilution of the solvent decreases the migration, but increases the transfer distance, so that the transfer efficiency remains practically constant. The excimer formation and dissociation rate parameters in the pure alkyl benzenes are evaluated. ...

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Fluorescence resonance energy transfer (FRET) is a distance-dependent interaction between the electronic excited states of two dye molecules in which excitation is transferred from a donor molecule to an acceptor molecule without emission of a photon.

Fluorescence resonance energy transfer (FRET) is a fluorescence microscopy technique suitable for live cells and capable of detecting changes in the conformational state of a single protein or the distance between two interacting proteins when the proteins are conjugated with appropriate donor and acceptor fluorophores

Monitoring protein conformations and interactions by fluorescence resonance energy transfer between mutants of green fluorescent protein

LOC FOR DETECTION OF HYBRIDIZATION OF NUCLEIC ACID SEQUENCES WITH FLUORESCENCE RESONANCE ENERGY TRANSFER (FRET) PROBES - diagram, schematic, and image 54 ...

BioTek 白皮书, 06/20 2005, An Introduction to Fluorescence Resonance Energy Transfer (FRET) Technology and its Application in Bioscience

TY - JOUR. T1 - Electronic spectroscopy of intermediates involved in the conversion of methane to methanol by FeO+. AU - Aguirre, Fernando. AU - Husband, John. AU - Thompson, Christopher J.. AU - Stringer, Kay L.. AU - Metz, Ricardo B.. PY - 2002/3/8. Y1 - 2002/3/8. N2 - The reaction intermediates [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ by photodissociation were studied. On the basis of experimental results and calculations performed at the B3LYP and TD3LYP level, excited state vibrational frequencies as well as geometry changes upon photoexcitation in [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ were determined.. AB - The reaction intermediates [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ by photodissociation were studied. On the basis of experimental results and calculations performed at the B3LYP and TD3LYP level, excited state vibrational frequencies as well as geometry changes upon photoexcitation in [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ were determined.. UR - ...

Ralph struggled for years digesting childhood trauma, because he never could reconcile a repeated tug of war between two mind states that kept painfully repeating themselves in everyday life. Either he reflected on his trauma and he felt like he was intellectually examining someone elses experience from afar without much details of experience, or he got plunged into reliving the trauma in all its details and felt he was drowning in a tornado of unbearable pain. This left him at a loss as to which view point is the truth.. Our organism is fundamentally energy flow organized into a temporarily well orchestrated collection of interrelated energy flow processes of different kinds and complexities. As such we are energy flow processing machines capable of modulating this energy flow in different complex ways that manifest as different organismic structures, from cells to organs, organ systems and minds. As energy enters our organism through its senses, it first flows in an unencumbered way, only ...

Using low energy electron (LEE) as a catalyst, the electronic origin of the catalytic strategies corresponding to substrate selectivity, reaction specificity and reaction rate enhancement are investigated for a reversible unimolecular elementary reaction. An electronic energy complementarity between the catalyst and the substrate molecule is the origin of substrate selectivity and reaction specificity. The electronic energy complementarity is induced by tuning the electronic energy of the catalyst. The energy complementarity maximizes the binding forces between the catalyst and the molecule. Consequently, a new electronically metastable high-energy reactant state and a corresponding new low barrier reaction path are resonantly created for a specific reaction of the substrate through the formation of a catalyst-substrate transient adduct. The LEE catalysis also reveals a fundamental \textit{structure-energy correspondence} in the formation of the catalyst-substrate transient adduct. Since the ...

Novel linkers for linking a donor dye to an acceptor dye in an energy transfer fluorescent dye are provided. These linkers faciliate the efficient transfer of energy between a donor and acceptor dye in an energy transfer dye. One of these linkers for linking a donor dye to an acceptor dye in an energy transfer fluorescent dye has the general structure R21Z1C(O)R22R28 where R21 is a C1-5 alkyl attached to the donor dye, C(O) is a carbonyl group, Z1 is either NH, sulfur or oxygen, R22 is a substituent which includes an alkene, diene, alkyne, a five and six membered ring having at least one unsaturated bond or a fused ring structure which is attached to the carbonyl carbon, and R28 includes a functional group which attaches the linker to the acceptor dye.

We focus on problems with elucidation of site energies (E-0(n)) for photosynthetic complexes (PSCs) in order to raise some genuine concern regarding the conflicting estimations propagating in the literature. As an example, we provide a stern assessment of the site energies extracted from fits to optical spectra of the widely studied CP47 antenna complex of photosystem II from spinach, though many general comments apply to other PSCs as well. Correct values of E-0(n) for chlorophyll (Chl) a in CP47 are essential for understanding its excitonic structure, population dynamics, and excitation energy pathway(s). To demonstrate this, we present a case study where simultaneous fits of multiple spectra (absorption, emission, circular dichroism, and nonresonant hole-burned spectra) show that several sets of parameters can fit the spectra very well. Importantly, we show that variable emission maxima (690-695 nm) and sample-dependent bleaching in nonresonant hole-burning spectra reported in literature ...

Transition paths of macromolecular conformational changes such as protein folding are predicted to be heterogeneous. However, experimental characterization of the diversity of transition paths is extremely challenging because it requires measuring more than one distance during individual transitions. In this work, we used fast three-color single-molecule Förster resonance energy transfer spectroscopy to obtain the distribution of binding transition paths of a disordered protein. About half of the transitions follow a path involving strong non-native electrostatic interactions, resulting in a transition time of 300 to 800 microseconds. The remaining half follow more diverse paths characterized by weaker electrostatic interactions and more than 10 times shorter transition path times. The chain flexibility and non-native interactions make diverse binding pathways possible, allowing disordered proteins to bind faster than folded proteins. ...

Instead, we must do a better instructional job of helping students to realize that it takes energy to break bonds and can release energy when bonds are created. In the end, there really needs to be a comprehensive model that takes into account both bond making, bond breaking, and the net energy transfer after a chemical reaction is completed. Focusing on energy transfer in chemical reactions proves, according to Galleys article and the Modeling Instruction research, far more useful in communicating a coherent view of energy. Galley also promotes schematic diagrams to represent the energy transfer in systems, which he describes happens more frequently in college-level chemistry courses. Other recommendations from Galley include, teaching the difference in bond energy between substances more explicitly, as well as better communicating that the bond energy refers to energy required to break a bond. These changes can make clear that it takes energy to break bonds and releases energy to make bonds; ...

Exploring charge and energy transport in donor-bridge-acceptor systems is an important research field which is essential for the fundamental knowledge necessary to develop future applications. These studies help creating valuable knowledge to respond to todays challenges to develop functionalized molecular systems for artificial photosynthesis, photovoltaics or molecular scale electronics. This tutorial review focuses on photo-induced charge/energy transfer in covalently linked donor-bridge-acceptor (D-B-A) systems. Of utmost importance in such systems is to understand how to control signal transmission, i.e. how fast electrons or excitation energy could be transferred between the donor and acceptor and the role played by the bridge (the molecular wire). After a brief description of the electron and energy transfer theory, we aim to give a simple yet accurate picture of the complex role played by the bridge to sustain donor-acceptor electronic communication. Special emphasis is put on understanding

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A description is given of the kinetics of the prompt and delayed luminescence components from aromatic materials excited by ionizing radiation. A theoretical model has been developed to describe the origin of the delayed scintillation component. From initial assumptions of molecular triplet state diffusion and triplet-triplet annihilation to form delayed singlet states, equations are obtained defining the intensity of the delayed component with time. These equations are shown to agree well with existing experimental results. From the comparison the following parameters for triplet excitations in anthracene and stilbene crystals have been calculated: diffusion constant, 6 x 10-6 cm2 s-1 (anthracene) and 3 x 10-6 cm2 s-1 (stilbene); triplet-triplet interaction rate constant, 1·3 x 10-11 cm3 s-1 (anthracene) and 7·5 x 10-12 cm3 s-1 (stilbene); and diffusion length, 3·5 x 10-4 cm (anthracene). ...

Development of versatile, chemically tunable photocages for photoactivated chemotherapy (PACT) represents an excellent opportunity to address the technical drawbacks of conventional photodynamic therapy (PDT) whose oxygen-dependent nature renders it inadequate in certain therapy contexts such as hypoxic tumors. As an alternative to PDT, oxygen free mechanisms to generate cytotoxic reactive oxygen species (ROS) by visible light cleavable photocages are in demand. Here, we report the detailed mechanisms by which the small molecule blebbistatin acts as a one-photon blue light-gated or two-photon near-infrared light-gated photocage to directly release a hydroxyl radical (•OH) in the absence of oxygen. By using femtosecond transient absorption spectroscopy and chemoselective ROS fluorescent probes, we analyze the dynamics and fate of blebbistatin during photolysis under blue light. Water-dependent photochemistry reveals a critical process of water-assisted protonation and excited state intramolecular

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TY - JOUR. T1 - Radiative and non-radiative decays from the excited state of Ti3+ ions in oxide crystals. AU - Yamaga, M.. AU - Gao, Y.. AU - Rasheed, F.. AU - ODonnell, K. P.. AU - Henderson, B.. AU - Cockayne, B.. PY - 1990/11/1. Y1 - 1990/11/1. N2 - The fluorescence spectra of Ti3+ in Y3Al5O12 (YAG), Al2O3 (sapphire), YAlO3 (YAP) observed at 10 K are composed of zero-phonon lines accompanied by the broad vibronic sidebands. The temperature dependence of the fluorescence lifetime and of the total intensity of the broadband measured in YAG and Al2O3 indicate that the radiative decay times from the excited states are nearly constant in the range 10-300 K. This demonstrates that the broadband radiative emissions in Ti3+:YAG and Ti3+:Al2O3 are due to magnetic dipole transitions or to electric dipole transitions induced by static odd-parity distortion, respectively. The decrease of the fluorescence lifetime with increasing temperature in Ti3+:YAG and Ti3+:Al2O3 is due to non-radiative decay from ...

Disclosed is a method for transferring energy wirelessly including transferring energy wirelessly from a first resonator structure to an intermediate resonator structure, wherein the coupling rate between the first resonator structure and the intermediate resonator structure is .kappa..sub.1B, transferring energy wirelessly from the intermediate resonator structure to a second resonator structure, wherein the coupling rate between the intermediate resonator structure and the second resonator structure is .kappa..sub.B2, and during the wireless energy transfers, adjusting at least one of the coupling rates .kappa..sub.1B and .kappa..sub.B2 to reduce energy accumulation in the intermediate resonator structure and improve wireless energy transfer from the first resonator structure to the second resonator structure through the intermediate resonator structure.

The fourth transmembrane helix (S4) is the primary voltage-sensor of voltage-gated ion channels. Recent studies have used fluorescence resonance energy transfer as a spectroscopic ruler to determine the nature and magnitude of the voltage-induced movement of S4 that leads to channel opening.

Automated fluorescence lifetime imaging high-content analysis of Förster resonance energy transfer between endogenously labeled kinetochore proteins in live budding yeast cells

The Hartree-Fock method in 6-311G** molecular orbitals basis set has been applied to calculations of proton affinities and proton transfer reaction energie