Air Ionization: The dissociation of molecules in the air into positive and negative ions under the influence of an electric field.Air: The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.Radiometry: The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.Film Dosimetry: Use of a device (film badge) for measuring exposure of individuals to radiation. It is usually made of metal, plastic, or paper and loaded with one or more pieces of x-ray film.Particle Accelerators: Devices which accelerate electrically charged atomic or subatomic particles, such as electrons, protons or ions, to high velocities so they have high kinetic energy.Scintillation Counting: Detection and counting of scintillations produced in a fluorescent material by ionizing radiation.Radiotherapy, High-Energy: Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; x-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle.Dictionaries, MedicalFlame Ionization: Pyrolysis of organic compounds at the temperature of a hydrogen-air flame to produce ionic intermediates which can be collected and the resulting ion current measured by gas chromatography.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Oils, Volatile: Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). The synonym essential oils refers to the essence of a plant, as its perfume or scent, and not to its indispensability.Confined Spaces: A space which has limited openings for entry and exit combined with unfavorable natural ventilation such as CAVES, refrigerators, deep tunnels, pipelines, sewers, silos, tanks, vats, mines, deep trenches or pits, vaults, manholes, chimneys, etc.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Gases: The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)Ozone: The unstable triatomic form of oxygen, O3. It is a powerful oxidant that is produced for various chemical and industrial uses. Its production is also catalyzed in the ATMOSPHERE by ULTRAVIOLET RAY irradiation of oxygen or other ozone precursors such as VOLATILE ORGANIC COMPOUNDS and NITROGEN OXIDES. About 90% of the ozone in the atmosphere exists in the stratosphere (STRATOSPHERIC OZONE).Xanthine: A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)Oxidants, Photochemical: Compounds that accept electrons in an oxidation-reduction reaction. The reaction is induced by or accelerated by exposure to electromagnetic radiation in the spectrum of visible or ultraviolet light.Pentosyltransferases: Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.Air Pollutants: 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.Leishmania donovani: A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes visceral leishmaniasis (LEISHMANIASIS, VISCERAL). The sandfly genera Phlebotomus and Lutzomyia are the vectors.Noble Gases: Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.Physics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.Krypton: A noble gas that is found in the atmosphere. It has the atomic symbol Kr, atomic number 36, atomic weight 83.80, and has been used in electric bulbs.Xenon: A noble gas with the atomic symbol Xe, atomic number 54, and atomic weight 131.30. It is found in the earth's atmosphere and has been used as an anesthetic.Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.Treatment Outcome: 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.Antineoplastic Combined Chemotherapy Protocols: The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.Salvage Therapy: A therapeutic approach, involving chemotherapy, radiation therapy, or surgery, after initial regimens have failed to lead to improvement in a patient's condition. Salvage therapy is most often used for neoplastic diseases.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.MedlinePlus: NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.Quality Control: A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)Perceptual Distortion: Lack of correspondence between the way a stimulus is commonly perceived and the way an individual perceives it under given conditions.Otoacoustic Emissions, Spontaneous: Self-generated faint acoustic signals from the inner ear (COCHLEA) without external stimulation. These faint signals can be recorded in the EAR CANAL and are indications of active OUTER AUDITORY HAIR CELLS. Spontaneous otoacoustic emissions are found in all classes of land vertebrates.Animal Testing Alternatives: Procedures, such as TISSUE CULTURE TECHNIQUES; mathematical models; etc., when used or advocated for use in place of the use of animals in research or diagnostic laboratories.Equipment Safety: Freedom of equipment from actual or potential hazards.United States Food and Drug Administration: An agency of the PUBLIC HEALTH SERVICE concerned with the overall planning, promoting, and administering of programs pertaining to maintaining standards of quality of foods, drugs, therapeutic devices, etc.Device Approval: Process that is gone through in order for a device to receive approval by a government regulatory agency. This includes any required preclinical or clinical testing, review, submission, and evaluation of the applications and test results, and post-marketing surveillance. It is not restricted to FDA.Health Educators: Professionals who plan, organize and direct health education programs for the individual, groups and the community.Healthy People Programs: Healthy People Programs are a set of health objectives to be used by governments, communities, professional organizations, and others to help develop programs to improve health. It builds on initiatives pursued over the past two decades beginning with the 1979 Surgeon General's Report, Healthy People, Healthy People 2000: National Health Promotion and Disease Prevention Objectives, and Healthy People 2010. These established national health objectives and served as the basis for the development of state and community plans. These are administered by the Office of Disease Prevention and Health Promotion (ODPHP). Similar programs are conducted by other national governments.Health Promotion: Encouraging consumer behaviors most likely to optimize health potentials (physical and psychosocial) through health information, preventive programs, and access to medical care.Health Behavior: Behaviors expressed by individuals to protect, maintain or promote their health status. For example, proper diet, and appropriate exercise are activities perceived to influence health status. Life style is closely associated with health behavior and factors influencing life style are socioeconomic, educational, and cultural.Science: The study of natural phenomena by observation, measurement, and experimentation.Life Style: Typical way of life or manner of living characteristic of an individual or group. (From APA, Thesaurus of Psychological Index Terms, 8th ed)Water Purification: Any of several processes in which undesirable impurities in water are removed or neutralized; for example, chlorination, filtration, primary treatment, ion exchange, and distillation. It includes treatment of WASTE WATER to provide potable and hygienic water in a controlled or closed environment as well as provision of public drinking water supplies.Household Articles: Various material objects and items in the home. It includes temporary or permanent machinery and appliances. It does not include furniture or interior furnishings (FURNITURE see INTERIOR DESIGN AND FURNISHINGS; INTERIOR FURNISHINGS see INTERIOR DESIGN AND FURNISHINGS).Filtration: A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Air Conditioning: The maintenance of certain aspects of the environment within a defined space to facilitate the function of that space; aspects controlled include air temperature and motion, radiant heat level, moisture, and concentration of pollutants such as dust, microorganisms, and gases. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)China: A country spanning from central Asia to the Pacific Ocean.Rumen: The first stomach of ruminants. It lies on the left side of the body, occupying the whole of the left side of the abdomen and even stretching across the median plane of the body to the right side. It is capacious, divided into an upper and a lower sac, each of which has a blind sac at its posterior extremity. The rumen is lined by mucous membrane containing no digestive glands, but mucus-secreting glands are present in large numbers. Coarse, partially chewed food is stored and churned in the rumen until the animal finds circumstances convenient for rumination. When this occurs, little balls of food are regurgitated through the esophagus into the mouth, and are subjected to a second more thorough mastication, swallowed, and passed on into other parts of the compound stomach. (From Black's Veterinary Dictionary, 17th ed)

Factors influencing the analytical performance of an atmospheric sampling glow discharge ionization source as revealed via ionization dynamics modeling. (1/24)

A kinetic model is developed for the dynamic events occurring within an atmospheric sampling glow discharge that affect its performance as an ion source for analytical mass spectrometry. The differential equations incorporate secondary electron generation and thermalization, reagent and analyte ion formation via electron capture and ion-molecule reactions, ion loss via recombination processes, diffusion, and ion-molecule reactions with matrix components, and the sampling and pumping parameters of the source. Because the ion source has a flow-through configuration, the number densities of selected species can be estimated by applying the steady-state assumption. However, understanding of its operation is aided by knowledge of the dynamic behavior, so numerical methods are applied to examine the time dependence of those species as well. As in other plasma ionization sources, the ionization efficiency is essentially determined by the ratio of the relevant ion formation and recombination rates. Although thermal electron and positive reagent ion number densities are comparable, the electron capture/ion-molecule reaction rate coefficient ratio is normally quite large and the ion-electron recombination rate coefficient is about an order of magnitude greater than that for ion-ion recombination. Consequently, the efficiency for negative analyte ion formation via electron capture is generally superior to that for positive analyte ion generation via ion-molecule reaction. However, the efficiency for positive analyte ion formation should be equal to or better than that for negative analyte ions when both ionization processes occur via ion-molecule reaction processes (with comparable rate coefficients), since the negative reagent ion density is considerably less than that for positive reagent ions. Furthermore, the particularly high number densities of thermal electrons and reagent ions leads to a large dynamic range of linear response for the source. Simulation results also suggest that analyte ion number densities might be enhanced by modification of the standard physical and operating parameters of the source.  (+info)

Millisecond pulsed radio frequency glow discharge time of flight mass spectrometry: temporal and spatial variations in molecular energetics. (2/24)

The internal energy distributions, P(epsilon), of a millisecond pulsed radio frequency glow discharge plasma were investigated using tungsten hexcarbonyl W(CO)(6) as a "thermometer molecule". Vapor of the probe molecule, W(CO)(6), was introduced into the plasma and subjected to various ionization and excitation processes therein. The resultant molecular and fragment ions were monitored using a Time-of-Flight mass spectrometer. Ion abundance data were utilized in combination with the known energetics of W(CO)(6) to construct the P(epsilon) plots. The P(epsilon) of W(CO)(6) exhibited strong temporal dependence over the pulse cycle: Distinct internal energy distributions were found at the discharge breakdown period (prepeak), the steady state period (plateau), and the post-pulse period (afterpeak). Spatial variation in P(epsilon) was also observed, especially during the plateau regime. The observations suggest that this pulsed glow discharge affords excellent energy tunability that can be used to perform selective ionization and fragmentation for molecular, structural, and elemental information. Parametric studies were performed to evaluate the effects of discharge pressure and operating power on P(epsilon). These studies also provided insight into the correlation of the observed P(epsilon)s with the fundamental ionization and excitation mechanisms in the plasma. The temporal and spatial variations in P(epsilon) were hence attributed to changes in the dominant energy transfer processes at specific times in specific regions of the plasma. These data will be useful in future efforts to optimize the analytical performance of this source for chemical speciation.  (+info)

Comparison of electrospray ionization, atmospheric pressure chemical ionization, and atmospheric pressure photoionization for the analysis of dinitropyrene and aminonitropyrene LC-MS/MS. (3/24)

The only relevant source for human exposure to dinitropyrenes is diesel engine emissions. Due to this specificity, dinitropyrenes may be used as biomarkers for monitoring human exposure to diesel engine emissions. Only few analytical methods have been described for the quantitation of dinitropyrenes and their metabolites, aminonitropyrenes, and diaminopyrenes. Therefore, for dinitropyrenes, aminonitropyrenes, and diaminopyrenes were selected as model compounds for the development of a sensitive HPLC-MS/MS method (high performance liquid chromatography coupled to triple quadrupole mass spectrometry) was to quantify polyaromatic amines and nitroarenes in biological matrices was developed optimal methods by comparing electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI) sources. Dinitropyrene was not effectively ionized and diaminopyrene yielded mainly [M(.)](+) ions by electrospray ionization. With APCI and APPI, precursor ions of diaminopyrene and aminonitropyrene were [M + H](+) and [M(.)](-) for dinitropyrene. Precursor ions with [M - 30(.)](-) for dinitropyrene and [M - 30 + H](+) for aminonitropyrene were observed. Reversed and normal phase HPLC-MS/MS with ESI, APCI and APPI were optimized separately with respect to unequivocal analyte identification and sensitivity. Normal phase HPLC coupled to APPI-MS/MS gave the highest precision and sensitivity for aminonitropyrene (6%/0.2 pg on column) and dinitropyrene (9%/0.5 pg on column). The limit of detection in spiked rat plasma was 5 pg/100 microL for aminonitropyrene (accuracy 82%) and 10 pg/100 microL for dinitropyrene (accuracy 105%). In plasma of rats treated with dinitropyrene by oral administration, no detectable levels of dinitropyrene but higher aminonitropyrene levels compared with intratracheal instillation were observed. These findings clearly demonstrate that dinitropyrene was absorbed after oral and intratracheal application and that a reduction of nitro groups occurs to a high extent in the reductive environment of the intestine. To our knowledge, this is the first time that aminonitropyrene was observed in plasma after intratracheal or oral administration directly demonstrating the reductive metabolism of dinitropyrene in vivo.  (+info)

Studies on the effects of ionization on bacterial aerosols in a burns and plastic surgery unit. (4/24)

The effect of the ionization of the air on the decay of bacterial aerosols was studied in a Burns and Plastic Surgery Unit. Ions were generated by free corona needles. The air content of bacteria measured by settle plates was found to be smaller during the ionization period than during the controls period. The number of individual phage typed Staph. aureus strains was especially found to be lower during ionization. The opposite potential increased the disappearance of bacteria from the air. The size of skin particles carrying bacteria is not optimum, but the results obtained show that the ionization may have applications in controlling airborne infection.  (+info)

Reduced flavin: NMR investigation of N5-H exchange mechanism, estimation of ionisation constants and assessment of properties as biological catalyst. (5/24)

BACKGROUND: The flavin in its FMN and FAD forms is a versatile cofactor that is involved in catalysis of most disparate types of biological reactions. These include redox reactions such as dehydrogenations, activation of dioxygen, electron transfer, bioluminescence, blue light reception, photobiochemistry (as in photolyases), redox signaling etc. Recently, hitherto unrecognized types of biological reactions have been uncovered that do not involve redox shuffles, and might involve the reduced form of the flavin as a catalyst. The present work addresses properties of reduced flavin relevant in this context. RESULTS: N(5)-H exchange reactions of the flavin reduced form and its pH dependence were studied using the 15N-NMR-signals of 15N-enriched, reduced flavin in the pH range from 5 to 12. The chemical shifts of the N(3) and N(5) resonances are not affected to a relevant extent in this pH range. This contrasts with the multiplicity of the N(5)-resonance, which strongly depends on pH. It is a doublet between pH 8.45 and 10.25 that coalesces into a singlet at lower and higher pH values. From the line width of the 15N(5) signal the pH-dependent rate of hydrogen exchange was deduced. The multiplicity of the 15N(5) signal and the proton exchange rates are little dependent on the buffer system used. CONCLUSION: The exchange rates allow an estimation of the pKa value of N(5)-H deprotonation in reduced flavin to be >or= 20. This value imposes specific constraints for mechanisms of flavoprotein catalysis based on this process. On the other hand the pK asymptotically equal to 4 for N(5)-H protonation (to form N(5)+-H2) would be consistent with a role of N(5)-H as a base.  (+info)

Hospital-acquired legionnaires disease in a university hospital: impact of the copper-silver ionization system. (6/24)

We evaluated the impact of the copper-silver ionization system in a hospital where hyperendemic nosocomial legionellosis and was present and all previous disinfection measures had failed. After implementation of the copper-silver ionization system, environmental colonization with Legionella species decreased significantly, and the incidence of nosocomial legionellosis decreased dramatically, from 2.45 to 0.18 cases per 1000 patient discharges.  (+info)

Bactericidal action of positive and negative ions in air. (7/24)

BACKGROUND: In recent years there has been renewed interest in the use of air ionisers to control of the spread of airborne infection. One characteristic of air ions which has been widely reported is their apparent biocidal action. However, whilst the body of evidence suggests a biocidal effect in the presence of air ions the physical and biological mechanisms involved remain unclear. In particular, it is not clear which of several possible mechanisms of electrical origin (i.e. the action of the ions, the production of ozone, or the action of the electric field) are responsible for cell death. A study was therefore undertaken to clarify this issue and to determine the physical mechanisms associated with microbial cell death. RESULTS: In the study seven bacterial species (Staphylococcus aureus, Mycobacterium parafortuitum, Pseudomonas aeruginosa, Acinetobacter baumanii, Burkholderia cenocepacia, Bacillus subtilis and Serratia marcescens) were exposed to both positive and negative ions in the presence of air. In order to distinguish between effects arising from: (i) the action of the air ions; (ii) the action of the electric field, and (iii) the action of ozone, two interventions were made. The first intervention involved placing a thin mica sheet between the ionisation source and the bacteria, directly over the agar plates. This intervention, while leaving the electric field unaltered, prevented the air ions from reaching the microbial samples. In addition, the mica plate prevented ozone produced from reaching the bacteria. The second intervention involved placing an earthed wire mesh directly above the agar plates. This prevented both the electric field and the air ions from impacting on the bacteria, while allowing any ozone present to reach the agar plate. With the exception of Mycobacterium parafortuitum, the principal cause of cell death amongst the bacteria studied was exposure to ozone, with electroporation playing a secondary role. However in the case of Mycobacterium parafortuitum, electroporation resulting from exposure to the electric field appears to have been the principal cause of cell inactivation. CONCLUSION: The results of the study suggest that the bactericidal action attributed to negative air ions by previous researchers may have been overestimated.  (+info)

The detection of airborne transmission of tuberculosis from HIV-infected patients, using an in vivo air sampling model. (8/24)

BACKGROUND: Nosocomial transmission of tuberculosis remains an important public health problem. We created an in vivo air sampling model to study airborne transmission of tuberculosis from patients coinfected with human immunodeficiency virus (HIV) and to evaluate environmental control measures. METHODS: An animal facility was built above a mechanically ventilated HIV-tuberculosis ward in Lima, Peru. A mean of 92 guinea pigs were continuously exposed to all ward exhaust air for 16 months. Animals had tuberculin skin tests performed at monthly intervals, and those with positive reactions were removed for autopsy and culture for tuberculosis. RESULTS: Over 505 consecutive days, there were 118 ward admissions by 97 patients with pulmonary tuberculosis, with a median duration of hospitalization of 11 days. All patients were infected with HIV and constituted a heterogeneous group with both new and existing diagnoses of tuberculosis. There was a wide variation in monthly rates of guinea pigs developing positive tuberculin test results (0%-53%). Of 292 animals exposed to ward air, 159 developed positive tuberculin skin test results, of which 129 had laboratory confirmation of tuberculosis. The HIV-positive patients with pulmonary tuberculosis produced a mean of 8.2 infectious quanta per hour, compared with 1.25 for HIV-negative patients with tuberculosis in similar studies from the 1950s. The mean monthly patient infectiousness varied greatly, from production of 0-44 infectious quanta per hour, as did the theoretical risk for a health care worker to acquire tuberculosis by breathing ward air. CONCLUSIONS: HIV-positive patients with tuberculosis varied greatly in their infectiousness, and some were highly infectious. Use of environmental control strategies for nosocomial tuberculosis is therefore a priority, especially in areas with a high prevalence of both tuberculosis and HIV infection.  (+info)

  • Two of the air-kerma standard chambers used in the comparison are parallel-plate free-air ionization chambers and the third standard is a variable volume cylindrical chamber. (thefreedictionary.com)
  • The theoretical aspects of dosimetry are given in the comprehensive chapter on cavity theory, followed by the description of primary measurement standards, ionization chambers, chemical dosimeters and solid state detectors. (wiley.com)
  • It describes options and how to calibrate plane parallel ionization chambers, against air kerma or absorbed dose to water standards at cobalt-60 gamma ray energies. (iaea.org)
  • ISDs principally differ in number and design of the measurement and reference chambers necessary for measuring the ionisation current and in the electronic evaluation system used. (bfs.de)
  • Attorney Agent or Flrmpamck Barren John A. Michnowicz, Santa Clara, both of Calif. ABSTRACT Assignee: newletbpackard Company, Palo This is an ion-producing source having a distinct Alto Calm chemical ionization configuration and a distinct electron impact configuration. (google.com)
  • An older RCT conducted by the same authors also found air ionization effective for SAD at 2.7x106 ions/cm3. (wikipedia.org)
  • The dissociation of molecules in the air into positive and negative ions under the influence of an electric field. (harvard.edu)
  • Electrospray ionization (ESI) is a technique used in mass spectrometry to produce ions using an electrospray in which a high voltage is applied to a liquid to create an aerosol. (wikipedia.org)
  • Ion generators, or ionizers, disperse charged ions into the air, similar to the electronic air cleaners but without a collector. (epa.gov)
  • Travelling fast and far the positive holes cause a range of follow-on reactions when they arrive at the Earth's surface, where they cause air ionization, injecting massive amounts of primarily positive air ions into the lower atmosphere. (mdpi.com)
  • They can be either small stand-alone devices or in the case of more sophisticated offerings, incorporated into heat, vacuum and air conditioning (HVAC) units in larger homes and other large dwellings and work spaces. (healthcentral.com)
  • Acceptable Indoor Air Concentration. (cdc.gov)
  • For example, the concentration of smoke particles can be reduced by clean air from nearby returns in other rooms. (ecmag.com)
  • If the GC/FID detects a high concentration of pollutants in the sample the chemists can dilute the sample (add extra clean air) so it doesn't damage the GC/MS. After the sample is analyzed they then multiply the results by the dilution factor (based on the amount of air added) to determine the actual concentration in the original sample. (in.gov)
  • 2NO2 + Mo  3 NO + MoO3 Possible interference: N-containing compounds  higher measured NO2 NO - NO2 - NOx EM - FT- IR Spectrometry www.k2bw.com/images/chem.gif Can you design an instrument that can measure the concentration of both NO and NO2 in the air? (slideserve.com)
  • There was linear dependence (r = 0.76) between the summary concentration of naphthols in urine and the naphthalene concentration in air. (nih.gov)
  • When the air heats up the electricity climes due to air which is electrically charged usually around 5000-20,000 volts but Jacob ladders can occur with 500,000 to 1 million volts at the transmission line, etc too. (instructables.com)
  • There is some limited evidence to support the effectiveness of acupuncture, light therapy (for non-seasonal depression), massage therapy, negative air ionisation (for winter depression), relaxation therapy, S -adenosylmethionine, folate and yoga breathing exercises. (mja.com.au)
  • The second area concerns itself with gaseous contaminates such as carbon monoxide, sulfur dioxide, etc. which are in solution with the air molecules. (google.com)
  • With the highest volume of customers and flights in the country, our terminals at LAX were often saturated with unwanted jet fumes, odors and other pollutants in the air. (plasma-air.com)
  • In the past 20 years, the instrumentation used for the sampling and analysis of air toxics has become much more sophisticated and much more accurate at measuring the levels of pollutants in the air. (in.gov)
  • The next logical step in the design of a combined air/water analyzer is the miniaturization of the plasma ion source itself by using a microplasma system, with the goal of reducing overall instrument size, required gas flow rates, and electrical power consumption. (springer.com)
  • These species also act to provide a source of protons to facilitate the ionization process. (wikipedia.org)
  • c. a voltage source coupled to the emitter and collector electrodes to produce a flow of air from the emitter electrode to the collector electrode, the voltage source configured to automatically produce a first flow of air during a start up period and a second flow of air after the start up period, wherein the first flow is greater than the second flow. (google.com.au)
  • Ambient- and indoor-air sampling indicated that there was no environmental source of contamination. (cdc.gov)
  • the ionization source can be changed 3.553. (google.com)
  • Those allergens are tracked back inside and spread all around your home, including in the air, creating a major source of recurring irritation for your pet's itchy skin . (mercola.com)
  • REHVA guidance targets common non-residential buildings and in this case, outdoor air is NOT a contamination source. (rehva.eu)
  • NFPA 72, section A.5-16.4.2, states, "In almost every fire scenario in an air handling system, the point of detection will be some distance from the fire source, therefore, the smoke will be cooler and more visible because of the growth of sub-micron particles into larger particles due to agglomeration and recombination. (ecmag.com)
  • Air is filtered by a mechanical filter, then odors are removed from the air, and the air is exposed to germicidal lamps for killing bacteria, then the air passes through a high efficiency electrostatically. (google.com)
  • Air quality contractors in Monterey County and San Benito County address a large variety of home air quality problems, but these problems fall into three basic categories: comfort, health, and energy efficiency. (diamondcertified.org)
  • A high efficiency air filtration method and apparatus utilizes a fibrous filter medium that is polarized by a high potential difference which exists between two electrodes. (google.com.ar)
  • Evaluating and mapping of spatial air ion quality patterns in a residential garden using a geostatistic method. (harvard.edu)
  • Current in-flight air monitoring systems provide the necessary information to accurately assess air quality in the International Space Station (ISS), but the information available regarding water quality is still limited. (springer.com)
  • These on-board technologies, however, lack specificity or only focus on a narrow class of analytes, and are not implemented in a fashion that enables simultaneous air and water quality assessment. (springer.com)
  • I'm pursuing several air quality issues at the same time and you might have seen my other thread on kitchen exhaust systems. (eng-tips.com)
  • Hong Kong, September 21, 2011) - CHI Residences is to become Hong Kong's first Serviced Apartment brand to provide superior indoor air quality that meets and exceeds World Health Organisation Standards (WHO) as adopted by the Hong Kong government through the introduction of Oxyvital air purification technology. (environmental-expert.com)
  • 2. What is IAQ ?Indoor Air Quality as defined by OSHA Malaysia,OSHA Singapore and ASHRAE standard 62-1989. (slideshare.net)
  • So quality air is always related to fresh air. (slideshare.net)
  • 2.Q: How do we know the air quality9 A:Indicator's color changing shows the air quality in the room. (alibaba.com)
  • Many dogs and cats these days have environmental allergies , including dust mite allergies, that can be triggered or made worse by poor air quality inside the home. (mercola.com)
  • Few things can impact your health and comfort more than your indoor air quality system. (diamondcertified.org)
  • Because most people spend more time at home than in any other single location, it is important to ensure that your indoor air quality and climate control system is serving your needs every day. (diamondcertified.org)
  • Add to this that air quality is not visibly detectable, and most ductwork and climate control systems are hidden, and you'll find that the process of achieving satisfactory indoor air quality is complex and mysterious to most consumers. (diamondcertified.org)
  • Fortunately, a qualified Monterey County or San Benito County indoor air quality contractor can assess the special needs of your home and offer an array of modifications or installations to ensure that the air in your home is as clean and comfortable as possible. (diamondcertified.org)
  • If your current air quality system does not satisfy you in all these areas, you need not suffer through sub-par home air quality, and in the case of a toxic home environment, it may be downright dangerous to neglect the problem. (diamondcertified.org)
  • The most common service that air quality contractors provide is improving the comfort of a home environment. (diamondcertified.org)
  • It's hard to put a price tag on the comfort and well being afforded by such air quality upgrades. (diamondcertified.org)
  • Fortunately, if your home has uneven heating or cooling, a licensed air quality contractor in Monterey County or San Benito County can test and locate any duct leaks using an Infiltrometer. (diamondcertified.org)
  • The two year small study offered data after researchers monitored air quality for 12 weeks in the homes of patients who had respiratory problems and compared it to outdoor air quality. (healthcentral.com)
  • Seminar room for analysing air quality and thermal comfort. (chalmers.se)
  • Many different types of studies can be carried out here into energy use, control, thermal comfort and air quality. (chalmers.se)
  • There are so many different types of monitors to detect different things in the air of homes, whether it be gas or smoke, in order to be protected numerous monitors are needed. (bartleby.com)
  • However, ambient ionization methods employing atmospheric plasmas typically require relatively high operation voltages and power, thus limiting their applicability in combination with fieldable mass spectrometers. (springer.com)
  • The air-liquid (a-l) interfacial chemistry of glyoxal is of great interest in atmospheric chemistry. (nature.com)
  • Secondary organic aerosol (SOA) formation occurring at the air-liquid (a-l) interface is important in atmospheric chemistry and its impact on global climate modeling. (nature.com)
  • Air purification and emission reduction have taken their place at the heart of the Entsorga-Enteco show in Cologne (27-30 October 2009), alongside waste and water management. (environmental-expert.com)
  • The tubes should not be subjected to temperatures exceeding 140º F. The supply air discharge of most gas and oil-fired furnaces can exceed 140º F, while hot water coils or electrical reheat coils typically don't exceed 110º F. (plasma-air.com)
  • Naphthalene homologues in air and their metabolites in urine samples were identified by gas chromatography-mass spectrometry. (nih.gov)
  • Smoke drifted from underneath the roof, causing my dog to sniff the air and look around, quite confused. (bartleby.com)
  • Diarrhea* 5 feet+ 160+ feet *As a result of toilet water aerosolization, air contamination in toilets need to be effectively sterilized and contained. (slideshare.net)
  • Traceable calibration of a therapy-level dosemeter in terms of absorbed dose to water or air kerma. (npl.co.uk)
  • Results of on-site sampling performed by the NRC, ORNL, and a DOE contractor found significant levels of radioactive materials in the groundwater, soils, and air. (cdc.gov)
  • The ionizations constant of a very weak acid, HA is 4.0 × 10 − 9 .Calculate the equilibrium concentrations of H 3 O + , A ‒ and HA in a 0.040M solution of the acid. (bartleby.com)
  • Concentrations of naphthalene and naphthols in breathing-zone air during a workshift and 1-naphthol and 2-naphthol in urine collected after the workshift were determined for 102 male workers. (nih.gov)
  • The time-weighted average concentrations of naphthalene and naphthols in the breathing-zone air showed that the exposure level of the workers was rather low. (nih.gov)
  • As well as a manual mode, with electronic AeraSmart sensors, the Fellowes AeraMax DX55 has auto mode allows the unit to regulate its speed according to the actual amount of particles and gaseous contaminants present in the air. (healthy-house.co.uk)
  • According to the European Norm DIN EN ISO 2560, there are a total of eight different types of coated stick electrodes for arc welding of unalloyed steels and fine-grained steel. (voestalpine.com)
  • Negative air ionization therapy is the use of air ionizers as an experimental non-pharmaceutical treatment for seasonal affective disorder (SAD) and mild depression. (wikipedia.org)
  • The effect of negative air ionisation was studied in three Norwegian poultry confinement buildings with compact cages for laying hens on different farms. (aaem.pl)
  • On UV-off days, ward air passed in parallel through a control animal enclosure and a similar enclosure containing negative ionizers. (whiterose.ac.uk)