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Sample records for chemical research organic

  1. BASIC CHEMICAL RESEARCH PROGRAM. ELECTRICAL PROPERTIES OF ORGANIC COMPOUNDS

    DTIC Science & Technology

    BENZENE, *CYANIDES, *HYDROXIDES, *ORGANIC COMPOUNDS, ACETYLENES, ALKYL RADICALS, AMIDES, ANILINES , BENZALDEHYDES, CHEMICAL REACTIONS , CONDENSATION... REACTIONS , ELECTRICAL CONDUCTIVITY, MATERIALS, MEASUREMENT, MONOCYCLIC COMPOUNDS, PHENOLS, PHENYL RADICALS, QUINONES, SOLID STATE PHYSICS, SYNTHESIS.

  2. Occupational exposure to chemicals and sensory organs: a neglected research field.

    PubMed

    Gobba, Fabriziomaria

    2003-08-01

    The effect of industrial chemicals on the sensory perception of exposed workers has received scant attention from the medical community to date, and the scientific literature is mainly limited to some case-reports or isolated studies. Possible explanations for this include the complexity of sensory perception, and the lack of agreement among researchers on methods for testing large groups of subjects. Nevertheless, some published studies showed that vision, hearing and olfactory function can be affected by various industrial metals and solvents, and some data exist also for touch and taste. This review discusses the main industrial chemicals involved. The pathogenesis of the toxicity of chemicals to sensory perception may be related to an action on receptors, nerve fibers, and/or the brain; probably, different pathogenetic mechanisms are involved. One of the main problems in this research field is that most of the studies to date evaluated the effect of a single industrial chemical on a single sense: as an example, we know that styrene exposure can impair smell and also hearing and vision but we have little idea whether different senses are impaired in the same worker, or whether each impairment is independent. In addition, workers are frequently exposed to different chemicals: co-exposure may have no effect, or result in both an increase or a decrease of the effect, as was observed for hearing loss, but studies on this aspect are largely insufficient. Research shows that both occupational and environmental exposure to industrial chemicals can affect sense organs, and suggests that the decline of perception with age may be, at least partly, related to this exposure. Nevertheless, available evidence is incomplete, and is largely inadequate for an estimation of a "safe" threshold of exposure. Good quality further research in this field is needed. This is certainly complex and demands adequate resources, but is justified by the ultimate result: the possibility to

  3. Research in the Field of Organic Photovoltaics at the Institute for Problems of Chemical Physics of Russian Academy of Sciences

    NASA Astrophysics Data System (ADS)

    Troshin, Pavel A.

    2015-08-01

    In the present review we highlight the main research activities in the field of organic photonics and photovoltaics at the Institute for Problems of Chemical Physics of Russian Academy of Sciences (IPCP RAS). Extensive investigation of optical and electrical properties of π-conjugated organic compounds performed at IPCP RAS since 1960's resulted in design of many exciting materials representing organic semiconductors, metals and superconductors. Organic Schottky barrier and p/n junction photovoltaic devices constructed at IPCP RAS in 1960's and 1970's were among the first examples of reasonably efficient organic solar cells at that time. These early discoveries inspired younger generations of the researchers to continue the work of their mentors and explore the world of organic materials and photonic devices such as molecular photonic switches, organic light emitting diodes, solar cells, photodetectors, photoswitchable organic field-effect transistors and memory elements.

  4. Organic chemical evolution

    NASA Technical Reports Server (NTRS)

    Chang, S.

    1981-01-01

    The course of organic chemical evolution preceding the emergence of life on earth is discussed based on evidence of processes occurring in interstellar space, the solar system and the primitive earth. Following a brief review of the equilibrium condensation model for the origin and evolution of the solar system, consideration is given to the nature and organic chemistry of interstellar clouds, comets, Jupiter, meteorites, Venus and Mars, and the prebiotic earth. Major issues to be resolved in the study of organic chemical evolution on earth are identified regarding condensation and accretion in the solar nebula, early geological evolution, the origin and evolution of the atmosphere, organic production rates, organic-inorganic interactions, environmental fluctuations, phase separation and molecular selectivity.

  5. Safer Chemicals Research

    EPA Pesticide Factsheets

    EPA's Chemical Safety research protects human health and the environment by evaluating chemicals for potential risk and providing tools and guidance for improved chemical production that supports a sustainable environment.

  6. Research Update: Mechanical properties of metal-organic frameworks - Influence of structure and chemical bonding

    NASA Astrophysics Data System (ADS)

    Li, Wei; Henke, Sebastian; Cheetham, Anthony K.

    2014-12-01

    Metal-organic frameworks (MOFs), a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  7. Groundwater and organic chemicals

    SciTech Connect

    Dawson, H.E.

    1995-12-01

    Groundwater is a major source of drinking water for many communities. Unfortunately, organic chemicals such as dry cleaning fluids, solvent, fuels, and pesticides have contaminated groundwater in many areas, rendering the groundwater useless as a drinking water resource. In many cases, the groundwater cannot be cleaned up with current technologies, particularly if the groundwater has been contaminated with immiscible (low solubility) organic liquids. In this talk, I will describe the path I have followed from geologist to geochemist and finally to environmental engineer. As a geologist, I studied the chemistry of rock metamorphosis. As a geochemist, I explored for gold and other metals. Now as an environmental engineer, I investigate the behavior of organic liquids in the subsurface. While these fields all appear very different, in reality I have always focused on the interaction of rocks or sediments with the fluids with which they come in contact.

  8. Organic Chemicals: Angels or Goblins?

    ERIC Educational Resources Information Center

    Ferguson, Lloyd N.

    1978-01-01

    Discusses some of the controversial organic chemical substances such as DDT, Red Dye No. 2, DES, Tris, Laetrile, cyclamate, and saccharin. Concludes that the use of some has to be considered on a benefit/risk ratio. (GA)

  9. Reproducibility in Chemical Research.

    PubMed

    Bergman, Robert G; Danheiser, Rick L

    2016-10-04

    "… To what extent is reproducibility a significant issue in chemical research? How can problems involving irreproducibility be minimized? … Researchers should be aware of the dangers of unconscious investigator bias, all papers should provide adequate experimental detail, and Reviewers have a responsibility to carefully examine papers for adequacy of experimental detail and support for the conclusions …" Read more in the Editorial by Robert G. Bergman and Rick L. Danheiser.

  10. Dryden Flight Research Center Chemical Pharmacy Program

    NASA Technical Reports Server (NTRS)

    Davis, Bette

    1997-01-01

    The Dryden Flight Research Center (DFRC) Chemical Pharmacy "Crib" is a chemical sharing system which loans chemicals to users, rather than issuing them or having each individual organization or group purchasing the chemicals. This cooperative system of sharing chemicals eliminates multiple ownership of the same chemicals and also eliminates stockpiles. Chemical management duties are eliminated for each of the participating organizations. The chemical storage issues, hazards and responsibilities are eliminated. The system also ensures safe storage of chemicals and proper disposal practices. The purpose of this program is to reduce the total releases and transfers of toxic chemicals. The initial cost of the program to DFRC was $585,000. A savings of $69,000 per year has been estimated for the Center. This savings includes the reduced costs in purchasing, disposal and chemical inventory/storage responsibilities. DFRC has chemicals stored in 47 buildings and at 289 locations. When the program is fully implemented throughout the Center, there will be three chemical locations at this facility. The benefits of this program are the elimination of chemical management duties; elimination of the hazard associated with chemical storage; elimination of stockpiles; assurance of safe storage; assurance of proper disposal practices; assurance of a safer workplace; and more accurate emissions reports.

  11. Organizing research data.

    PubMed

    Sestoft, Peter

    2011-01-01

    Research relies on ever larger amounts of data from experiments, automated production equipment, questionnaries, times series such as weather records, and so on. A major task in science is to combine, process and analyse such data to obtain evidence of patterns and correlations.Most research data are on digital form, which in principle ensures easy processing and analysis, easy long-term preservation, and easy reuse in future research, perhaps in entirely unanticipated ways. However, in practice, obstacles such as incompatible or undocumented data formats, poor data quality and lack of familiarity with current technology prevent researchers from making full use of available data.This paper argues that relational databases are excellent tools for veterinary research and animal production; provides a small example to introduce basic database concepts; and points out some concerns that must be addressed when organizing data for research purposes.

  12. Color Coding Organic Chemicals for Inventory Control.

    ERIC Educational Resources Information Center

    Wystrach, V. P.; George, Babu

    1985-01-01

    Describes a system in which organic chemicals are recoded for inventory control and reshelving purposes. The system works well in undergraduate organic chemistry or biology laboratories but can be expanded to handle a larger and more complicated inventory. (JN)

  13. Mineralogical, chemical, organic and microbial properties of subsurface soil cores from Mars Desert Research Station (Utah, USA): Phyllosilicate and sulfate analogues to Mars mission landing sites

    NASA Astrophysics Data System (ADS)

    Stoker, Carol R.; Clarke, Jonathan; Direito, Susana O. L.; Blake, David; Martin, Kevin R.; Zavaleta, Jhony; Foing, Bernard

    2011-07-01

    We collected and analysed soil cores from four geologic units surrounding Mars Desert Research Station (MDRS) Utah, USA, including Mancos Shale, Dakota Sandstone, Morrison formation (Brushy Basin member) and Summerville formation. The area is an important geochemical and morphological analogue to terrains on Mars. Soils were analysed for mineralogy by a Terra X-ray diffractometer (XRD), a field version of the CheMin instrument on the Mars Science Laboratory (MSL) mission (2012 landing). Soluble ion chemistry, total organic content and identity and distribution of microbial populations were also determined. The Terra data reveal that Mancos and Morrison soils are rich in phyllosilicates similar to those observed on Mars from orbital measurements (montmorillonite, nontronite and illite). Evaporite minerals observed include gypsum, thenardite, polyhalite and calcite. Soil chemical analysis shows sulfate the dominant anion in all soils and SO4>>CO3, as on Mars. The cation pattern Na>Ca>Mg is seen in all soils except for the Summerville where Ca>Na. In all soils, SO4 correlates with Na, suggesting sodium sulfates are the dominant phase. Oxidizable organics are low in all soils and range from a high of 0.7% in the Mancos samples to undetectable at a detection limit of 0.1% in the Morrison soils. Minerals rich in chromium and vanadium were identified in Morrison soils that result from diagenetic replacement of organic compounds. Depositional environment, geologic history and mineralogy all affect the ability to preserve and detect organic compounds. Subsurface biosphere populations were revealed to contain organisms from all three domains (Archaea, Bacteria and Eukarya) with cell density between 3.0×106 and 1.8×107 cells ml-1 at the deepest depth. These measurements are analogous to data that could be obtained on future robotic or human Mars missions and results are relevant to the MSL mission that will investigate phyllosilicates on Mars.

  14. POLAR ORGANIC CHEMICAL INTEGRATIVE SAMPLING ...

    EPA Pesticide Factsheets

    The purpose of the research presented in this paper is two-fold: (1) to demonstrate the 4 coupling of two state-of-the-art techniques: a time-weighted polar organic integrative sampler (POCIS) and micro-liquid chromatography-electrospray/ion trap mass spectrometry (u-LC-6 ES/ITMS); and (2) the assessment of these methodologies in a real-world environment -wastewater effluent - for detecting six drugs (four prescription and two illicit). In the effluent from three wastewater treatment plants (WWTP), azithromycin was detected at concentrations ranging from 15ng/L to 66ng/L, equivalent to the total annual release of 0.4 -4 kg into the receiving waters. Detected and confirmed in the effluent from two WWTPs were two illicit drugs methamphetamine and methylenedioxymethamphetamine (MDMA), at 2ng/L and 0.5ng/L, respectively. While the ecotoxicological significance of drugs in environmental matrices, particularly water, has not been closely examined, it can only be surmised that these substances have the potential to adversely affect biota that are continuously exposed to them even at very low levels. The potential for chronic affects on human health is also unknown, but of increasing concern due to the multi use character of water, particularly in densely populated arid areas. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality

  15. COSOLVENCY AND SOPRTION OF HYDROPHOBIC ORGANIC CHEMICALS

    EPA Science Inventory

    Sorption of hydrophobic organic chemicals (HOCs) by two soils was measured from mixed solvents containing water plus completely miscible organic solvents (CMOSs) and partially miscible organic solvents (PMOSs). The utility of the log-linear cosolvency model for predicting HOC sor...

  16. Philosophical Confusion in Chemical Education Research.

    ERIC Educational Resources Information Center

    Scerri, Eric R.

    2003-01-01

    Presents the state of research in chemical education. Reviews the origins of chemical constructivism, behaviorism, and relativism. Discusses the differences between objectivism, realism, and positivism. Suggests remedies for chemical education research to become better acquainted with the philosophical position. (KHR)

  17. Subsurface flow and transport of organic chemicals: an assessment of current modeling capability and priority directions for future research (1987-1995)

    SciTech Connect

    Streile, G.P.; Simmons, C.S.

    1986-09-01

    Theoretical and computer modeling capability for assessing the subsurface movement and fate of organic contaminants in groundwater was examined. Hence, this study is particularly concerned with energy-related, organic compounds that could enter a subsurface environment and move as components of a liquid phase separate from groundwater. The migration of organic chemicals that exist in an aqueous dissolved state is certainly a part of this more general scenario. However, modeling of the transport of chemicals in aqueous solution has already been the subject of several reviews. Hence, this study emphasizes the multiphase scenario. This study was initiated to focus on the important physicochemical processes that control the behavior of organic substances in groundwater systems, to evaluate the theory describing these processes, and to search for and evaluate computer codes that implement models that correctly conceptualize the problem situation. This study is not a code inventory, and no effort was made to identify every available code capable of representing a particular process.

  18. Organic Chemicals from Bioprocesses in China

    NASA Astrophysics Data System (ADS)

    Huang, Jin; Huang, Lei; Lin, Jianping; Xu, Zhinan; Cen, Peilin

    Over the last 20 years, China has successfully established a modern biotechnology industry from almost nothing. Presently, China is a major producer of a vast array of products involving bioprocesses, for some China is even the world's top producer. The ever-increasing list of products includes organic acids, amino acids, antibiotics, solvents, chiral chemicals, biopesticides, and biopolymers. Herein, the research and development of bioprocesses in China will be reviewed briefly. We will concentrate on three categories of products: small molecules produced via fermentation, biopolymers produced via fermentation and small chemicals produced by enzyme-catalyzed reactions. In comparison with the traditional chemical process, in which, nonrenewable mineral resources are generally used, products in the first and second categories noted above can use renewable bioresources as raw materials. The bioprocesses are generally energy saving and environmentally benign. For products developed via the third category, although the raw materials still need to be obtained from mineral resources, the biocatalysts are more effective with higher selectivity and productivity, and the bioprocesses occur under ambient temperature and pressure, therefore, these are "green processes." Most of the products such as citric acid, xanthan and acrylamide etc., discussed in this paper have been in large-scale commercial production in China. Also introduced herein are three scientists, Prof. Shen Yinchu, Prof. Ouyang Pingkai and Prof. Chen Guoqiang, and six enterprises, Anhui Fengyuan Biochemical Co. Ltd., Shandong Hiland Biotechnology Co. Ltd., Shandong Fufeng Fermentation Co. Ltd., Shandong Bausch & Lomb-Freda Pharmaceutical Co. Ltd., Zhejiang Hangzhou Xinfu Pharmaceutical Co. Ltd., and Changzhou Changmao Biochemical Engineering Co. Ltd.; they have all contributed a great deal to research and development in the commercialization of bioprocesses.

  19. Organic chemicals from bioprocesses in China.

    PubMed

    Huang, Jin; Huang, Lei; Lin, Jianping; Xu, Zhinan; Cen, Peilin

    2010-01-01

    Over the last 20 years, China has successfully established a modern biotechnology industry from almost nothing. Presently, China is a major producer of a vast array of products involving bioprocesses, for some China is even the world's top producer. The ever-increasing list of products includes organic acids, amino acids, antibiotics, solvents, chiral chemicals, biopesticides, and biopolymers. Herein, the research and development of bioprocesses in China will be reviewed briefly. We will concentrate on three categories of products: small molecules produced via fermentation, biopolymers produced via fermentation and small chemicals produced by enzyme-catalyzed reactions. In comparison with the traditional chemical process, in which, nonrenewable mineral resources are generally used, products in the first and second categories noted above can use renewable bioresources as raw materials. The bioprocesses are generally energy saving and environmentally benign. For products developed via the third category, although the raw materials still need to be obtained from mineral resources, the biocatalysts are more effective with higher selectivity and productivity, and the bioprocesses occur under ambient temperature and pressure, therefore, these are "green processes." Most of the products such as citric acid, xanthan and acrylamide etc., discussed in this paper have been in large-scale commercial production in China. Also introduced herein are three scientists, Prof. Shen Yinchu, Prof. Ouyang Pingkai and Prof. Chen Guoqiang, and six enterprises, Anhui Fengyuan Biochemical Co. Ltd., Shandong Hiland Biotechnology Co. Ltd., Shandong Fufeng Fermentation Co. Ltd., Shandong Bausch & Lomb-Freda Pharmaceutical Co. Ltd., Zhejiang Hangzhou Xinfu Pharmaceutical Co. Ltd., and Changzhou Changmao Biochemical Engineering Co. Ltd.; they have all contributed a great deal to research and development in the commercialization of bioprocesses.

  20. EFFECT OF NON-TARGET ORGANICS ON ORGANIC CHEMICAL TRANSPORT

    EPA Science Inventory

    To improve our standard of living, man has synthesized organic compounds for use in products considered essential for life. These compounds are having and will continue to have a significant impact on the terrestrial environment. Understanding organic chemical transport through s...

  1. ESTIMATING DISSOLVED ORGANIC CARBON PARTITION COEFFICIENTS FOR NONIONIC ORGANIC CHEMICALS

    EPA Science Inventory

    A literature search was performed for dissolved organic carbon/water partition coefficients for nonionic chemicals (Kdoc) and Kdoc data was taken from more than sixty references. The Kdoc data were evaluated as a function of the n-octanol/water partition coefficients (Kow). A pre...

  2. Chemical Evolution of Presolar Organics in Astromaterials

    NASA Technical Reports Server (NTRS)

    Nakamura-Messenger, K.; Clemett, S. J.; Messenger, Scott; Keller, L. P.

    2010-01-01

    Sub-micron, hollow organic globules reported from several carbonaceous chondrites, interplanetary dust particles, and comet Wild-2 samples returned by NASA?s Stardust mission are enriched in N-15/N-14 and D/H compared with terrestrial materials and the parent materials [1-4]. These anomalies are ascribed to the preservation of presolar cold molecular cloud material from where H, C, and N isotopic constraints point to chemical fractionation near 10 K [5]. An origin well beyond the planet forming region and their survival in meteorites suggests submicrometer organic globules were once prevalent throughout the solar nebula. The survival of the membrane structures indicates primitive meteorites and cometary dust particles would have delivered these organic precursors to the early Earth as well as other planets and satellites. The physical, chemical, and isotopic properties of the organic globules varies to its meteorite types and its lithologies. For example, organic globules in the Tagish Lake meteorite are always embedded in fined grained (poorly crystallized) saponite, and hardly encapsulated in coarse grained serpentine, even though saponite and serpentine are both main components of phyllosilicate matrix of the Tagish Lake meteorite. The organic globules are commonly observed in the carbonate-poor lithology but not in the carbonate-rich one. In Tagish Lake, isolated single globules are common, but in the Bells (CM2) meteorite, globules are mostly aggregated. We will review the evolutions of the organic globules from its birth to alteration in the parent bodies in terms of its own physical and chemical properties as well as its associated minerals.

  3. Safer Chemicals Research Fact Sheets

    EPA Pesticide Factsheets

    Chemical safety is a major priority of the U.S. EPA. Moving toward a healthier, more sustainable environment requires making safer, “greener” chemicals and producing new and existing chemicals in ways that are safer for humans and wildlife.

  4. Chemical Safety for Sustainability: Research Action Plan

    EPA Pesticide Factsheets

    The Strategic Research Action Plan for EPA’s Chemical Safety for Sustainability research program presents the purpose, design and themes of the Agency’s research efforts to ensure safety in the design, manufacture and use of existing and future chemicals.

  5. Self-templated chemically stable hollow spherical covalent organic framework

    NASA Astrophysics Data System (ADS)

    Kandambeth, Sharath; Venkatesh, V.; Shinde, Digambar B.; Kumari, Sushma; Halder, Arjun; Verma, Sandeep; Banerjee, Rahul

    2015-04-01

    Covalent organic frameworks are a family of crystalline porous materials with promising applications. Although active research on the design and synthesis of covalent organic frameworks has been ongoing for almost a decade, the mechanisms of formation of covalent organic frameworks crystallites remain poorly understood. Here we report the synthesis of a hollow spherical covalent organic framework with mesoporous walls in a single-step template-free method. A detailed time-dependent study of hollow sphere formation reveals that an inside-out Ostwald ripening process is responsible for the hollow sphere formation. The synthesized covalent organic framework hollow spheres are highly porous (surface area ~1,500 m2 g-1), crystalline and chemically stable, due to the presence of strong intramolecular hydrogen bonding. These mesoporous hollow sphere covalent organic frameworks are used for a trypsin immobilization study, which shows an uptake of 15.5 μmol g-1 of trypsin.

  6. Self-templated chemically stable hollow spherical covalent organic framework.

    PubMed

    Kandambeth, Sharath; Venkatesh, V; Shinde, Digambar B; Kumari, Sushma; Halder, Arjun; Verma, Sandeep; Banerjee, Rahul

    2015-04-10

    Covalent organic frameworks are a family of crystalline porous materials with promising applications. Although active research on the design and synthesis of covalent organic frameworks has been ongoing for almost a decade, the mechanisms of formation of covalent organic frameworks crystallites remain poorly understood. Here we report the synthesis of a hollow spherical covalent organic framework with mesoporous walls in a single-step template-free method. A detailed time-dependent study of hollow sphere formation reveals that an inside-out Ostwald ripening process is responsible for the hollow sphere formation. The synthesized covalent organic framework hollow spheres are highly porous (surface area ∼1,500 m(2 )g(-1)), crystalline and chemically stable, due to the presence of strong intramolecular hydrogen bonding. These mesoporous hollow sphere covalent organic frameworks are used for a trypsin immobilization study, which shows an uptake of 15.5 μmol g(-1) of trypsin.

  7. Metal-Organic Frameworks for CO2 Chemical Transformations.

    PubMed

    He, Hongming; Perman, Jason A; Zhu, Guangshan; Ma, Shengqian

    2016-12-01

    Carbon dioxide (CO2 ), as the primary greenhouse gas in the atmosphere, triggers a series of environmental and energy related problems in the world. Therefore, there is an urgent need to develop multiple methods to capture and convert CO2 into useful chemical products, which can significantly improve the environment and promote sustainable development. Over the past several decades, metal-organic frameworks (MOFs) have shown outstanding heterogeneous catalytic activity due in part to their high internal surface area and chemical functionalities. These properties and the ability to synthesize MOF platforms allow experiments to test structure-function relationships for transforming CO2 into useful chemicals. Herein, recent developments are highlighted for MOFs participating as catalysts for the chemical fixation and photochemical reduction of CO2 . Finally, opportunities and challenges facing MOF catalysts are discussed in this ongoing research area.

  8. Chemical Engineering Division research highlights, 1979

    SciTech Connect

    Burris, L.; Webster, D. S.; Barney, D. L.; Cafasso, F. A.; Steindler, M. J.

    1980-06-01

    In 1979, CEN conducted research and development in the following areas: (1) high-temperature, rechargeable lithium/iron sulfide batteries for electric vehicles and electric utility load leveling; (2) ambient-temperature batteries - improved lead-acid, nickel/zinc, and nickel/iron - for electric vehicles; (3) molten carbonate fuel cells for use by electric utilities; (4) coal technology - mainly fluidized-bed combustion of coal in the presence of SO/sub 2/ sorbent of limestone; (5) heat- and seed- recovery technology for open-cycle magnetohydrodynamic systems; (6) solar energy collectors and thermal energy storage; (7) fast breeder reactor chemistry research - chemical support of reactor safety studies, chemistry of irradiated fuels, and sodium technology; (8) fuel cycle technology - reprocessing of nuclear fuels, management of nuclear wastes, geologic migration studies, and proof-of-breeding studies for the Light Water Breeder Reactor; (9) magnetic fusion research - lithium processing technology and materials research; and (10) basic energy sciences - homogeneous catalysis, thermodynamics of inorganic and organic materials, environmental chemistry, electrochemistry, and physical properties of salt vapors. Separate abstracts were prepared for each of these areas.

  9. REMOVAL OF ORGANIC CHEMICALS FROM WASTEWATER BY SURFACTANT SEPARATION

    SciTech Connect

    Unknown

    2002-01-01

    This research presents a novel hybrid process for removing organic chemicals from contaminated water. The process uses surfactant to carry out two unit operations (1) Extraction; (2) Foam flotation. In the first step, surfactant is used to extract most of the amounts of organic contaminants in the stream. In the second step, foam flotation is used to further reduce organic contaminants and recover surfactant from the stream. The process combines the advantages of extraction and foam flotation, which allows the process not only to handle a wide range of organic contaminants, but also to effectively treat a wide range of the concentration of organic contaminants in the stream and reduce it to a very low level. Surfactant regeneration can be done by conventional methods. This process is simple and low cost. The wastes are recoverable. The objective of this research is to develop an environmentally innocuous process for the wastewater or reclaimed water treatment with the ability to handle a wide range of organic contaminants, also to effectively treat a wide range of the concentration of organic contaminants in contaminated water and reduce it to a very low level, finally, provides simpler, less energy cost and economically-practical process design. Another purpose is to promote the environmental concern in minority students and encourage minority students to become more involved in environmental engineering research.

  10. Adsorption of organic chemicals in soils.

    PubMed Central

    Calvet, R

    1989-01-01

    This paper presents a review on adsorption of organic chemicals on soils sediments and their constituents. The first part of this review deals with adsorption from gas and liquid phases and gives a discussion on the physical meaning of the shape of adsorption isotherms. Results show that no general rules can be proposed to describe univocally the relation between the shape of isotherms and the nature of adsorbate-adsorbent system. Kinetics of adsorption is discussed through the description of various models. Theoretical developments exist both for the thermodynamics and the kinetics of adsorption, but there is a strong need for experimental results. Possible adsorption mechanisms are ion exchange, interaction with metallic cations, hydrogen bonds, charge transfers, and London-van der Waals dispersion forces/hydrophobic effect. However, direct proofs of a given mechanism are rare. Several factors influence adsorption behavior. Electronic structure of adsorbed molecules, properties of adsorbents, and characteristics of the liquid phase are discussed in relation to adsorption. Such properties as water solubility, organic carbon content of adsorbing materials, and the composition of the liquid phase are particularly important. Evaluation of adsorption can be obtained through either laboratory measurements or use of several correlations. Adsorption measurements must be interpreted, taking into account treatment of adsorbent materials, experimental conditions, and secondary phenomena such as degradations. Correlations between adsorption coefficients and water-octanol partition coefficient or water solubility are numerous. They may be useful tools for prediction purposes. Relations with transport, bioavailability, and degradation are described. PMID:2695323

  11. CHEMICAL DYNAMICS OF HYDROPHOBIC ORGANIC CONTAMINANTS DURING RESUSPENSION

    EPA Science Inventory

    Laboratory experiments were designed to study the chemical-particle dynamics of toxic hydrophobic organics during resuspension episodes using a particle entrainment simulator (PES). The purpose was to obtain insight into chemical transport mechanisms during resuspension. Informat...

  12. 27 CFR 478.145 - Research organizations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Research organizations... Exemptions, Seizures, and Forfeitures § 478.145 Research organizations. The provisions of § 478.98 with... organization designated by the Director to receive same. A research organization desiring such...

  13. 27 CFR 478.145 - Research organizations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Research organizations... Exemptions, Seizures, and Forfeitures § 478.145 Research organizations. The provisions of § 478.98 with... organization designated by the Director to receive same. A research organization desiring such...

  14. ECUT: Energy Conversion and utilization Technologies program biocatalysis research activity. Generation of chemical intermediates by catalytic oxidative decarboxylation of dilute organic acids

    NASA Technical Reports Server (NTRS)

    Distefano, S.; Gupta, A.; Ingham, J. D.

    1983-01-01

    A rhodium-based catalyst was prepared and preliminary experiments were completed where the catalyst appeared to decarboxylate dilute acids at concentrations of 1 to 10 vol%. Electron spin resonance spectroscoy was used to characterize the catalyst as a first step leading toward modeling and optimization of rhodium catalysts. Also, a hybrid chemical/biological process for the production of hydrocarbons has been assessed. These types of catalysts could greatly increase energy efficiency of this process.

  15. Integrating Chemical Information Instruction into the Chemistry Curriculum on Borrowed Time: A Multiyear Case Study of a Capstone Research Report for Organic Chemistry

    ERIC Educational Resources Information Center

    Jacobs, Danielle L.; Dalal, Heather A.; Dawson, Patricia H.

    2016-01-01

    To develop information literacy skills in chemistry and biochemistry majors at a primarily undergraduate institution, a multiyear collaboration between chemistry faculty and librarians has resulted in the establishment of a semester-long capstone project for Organic Chemistry II. Information literacy skills were instilled via a progressive…

  16. Membrane-Organized Chemical Photoredox Systems

    SciTech Connect

    Hurst, James K.

    2014-09-18

    This project has three interrelated goals relevant to solar water photolysis, which are to develop: (1) vesicle-organized assemblies for H2 photoproduction that utilize pyrylium and structurally related compounds as combined photosensitizers and cyclic electroneutral transmembrane electron carriers; (2) transmembrane redox systems whose reaction rates can be modulated by light; and (3) homogeneous catalysts for water oxidation. . In area (1), initial efforts to photogenerate H2 from vectorially-organized vesicles containing occluded colloidal Pt and commonly available pyrylium ions as transmembrane redox mediators were unsuccessful. New pyrylium compounds with significantly lower reduction potentials have been synthesized to address this problem, their apparent redox potentials in functioning systems have been now evaluated by using a series of occluded viologens, and H2 photoproduction has been demonstrated in continuous illumination experiments. In area (2), spirooxazine-quinone dyads have been synthesized and their capacity to function as redox mediators across bilayer membranes has been evaluated through continuous photolysis and transient spectrophotometric measurements. Photoisomerization of the spiro moiety to the ring-open mero form caused net quantum yields to decrease significantly, providing a basis for photoregulation of transmembrane redox. Research on water oxidation (area 3) has been directed at understanding mechanisms of catalysis by cis,cis-[(bpy)2Ru(OH2)]2O4+ and related polyimine complexes. Using a variety of physical techniques, we have: (i) identified the redox state of the complex ion that is catalytically active; (ii) shown using 18O isotopic labeling that there are two reaction pathways, both of which involve participation of solvent H2O; and (iii) detected and characterized by EPR and resonance Raman spectroscopies new species which may be key intermediates in the catalytic cycle.

  17. 40 CFR Table 1 to Subpart F of... - Synthetic Organic Chemical Manufacturing Industry Chemicals

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Synthetic Organic Chemical... POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table 1 Table 1 to Subpart F of Part...

  18. 40 CFR Table 1 to Subpart F of... - Synthetic Organic Chemical Manufacturing Industry Chemicals

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Synthetic Organic Chemical... POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table 1 Table 1 to Subpart F of Part...

  19. 40 CFR Table 1 to Subpart F of... - Synthetic Organic Chemical Manufacturing Industry Chemicals

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Synthetic Organic Chemical... POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table 1 Table 1 to Subpart F of Part...

  20. 40 CFR Table 1 to Subpart F of... - Synthetic Organic Chemical Manufacturing Industry Chemicals

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Synthetic Organic Chemical... POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table 1 Table 1 to Subpart F of Part...

  1. 40 CFR Table 1 to Subpart F of... - Synthetic Organic Chemical Manufacturing Industry Chemicals

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Synthetic Organic Chemical... POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table 1 Table 1 to Subpart F of Part...

  2. Chemically diverse and multifunctional hybrid organic-inorganic perovskites

    NASA Astrophysics Data System (ADS)

    Li, Wei; Wang, Zheming; Deschler, Felix; Gao, Song; Friend, Richard H.; Cheetham, Anthony K.

    2017-02-01

    Hybrid organic-inorganic perovskites (HOIPs) can have a diverse range of compositions including halides, azides, formates, dicyanamides, cyanides and dicyanometallates. These materials have several common features, including their classical ABX3 perovskite architecture and the presence of organic amine cations that occupy the A-sites. Current research in HOIPs tends to focus on metal halide HOIPs, which show promise for use in solar cells and optoelectronic devices; however, the other subclasses also exhibit a diverse range of physical properties. In this Review, we summarize the chemical variability and structural diversity of all known HOIP subclasses. We also present a comprehensive account of their intriguing physical properties, including photovoltaic and optoelectronic properties, dielectricity, magnetism, ferroelectricity, ferroelasticity and multiferroicity. Moreover, we discuss the current challenges and future opportunities in this exciting field.

  3. COSOLVENCY OF PARTIALLY MISCIBLE ORGANIC SOLVENTS ON THE SOLUBILITY OF HYDROPHOBIC ORGANIC CHEMICALS

    EPA Science Inventory

    The cosolvency of completely miscible organic solvents (CMOSs) and partially miscible organic solvents (PMOSs) on the solubility of hydrophobic organic chemicals (HOCs) was examined, with an emphasis on PMOSs. Measured solubilities were compared with predictions from the log- lin...

  4. LOSS OF ORGANIC CHEMICALS IN SOIL: PURE COMPOUND TREATABILITY STUDIES

    EPA Science Inventory

    Comprehensive screening data on the treatability of 32 organic chemicals in soil were developed. Of the evaluated chemicals, 22 were phenolic compounds. Aerobic batch laboratory microcosm experiments were conducted using two soils: an acidic clay soil with <1% organic matter and ...

  5. Synthetic Organic Chemicals: United States Production and Sales, 1976.

    ERIC Educational Resources Information Center

    Adams, Roger; And Others

    This is the sixth annual report of the U.S. Trade Commission on domestic production and sales of synthetic organic chemicals and the raw materials from which they are made. The report consists of 15 sections, each covering a specified group (based primarily on use) of organic chemicals as follows: tar and tar crudes; primary products from…

  6. Uptake, Metabolism, and Tissue Distribution of Chemicals in Organisms

    EPA Science Inventory

    This talk will explain how chemicals get into aquatic species, what tissues and organs the chemicals move into, and what can happen to the chemicals once they get there. This will be presented using examples from recent studies conducted using state-of-the-art microscopy with em...

  7. USDA/ARS Organic Production Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For much of its history, USDA/ARS had little to do with research on organic agriculture, however research in organic systems has made considerable gains at the agency over the past decade. In the 1980's and 1990's, as the organic food industry was taking off, ARS researchers who wanted to serve orga...

  8. Soviet chemical propellant research and development

    SciTech Connect

    deButts, E.H.; Baum, K.; Beckstead, M.W.; Christe, K.O.; Hartman, K.O.; Jeffrey, W.A.

    1991-12-01

    In the second half of the 1980s, the Soviet Union had a strong and continuing research effort devoted to understanding the behavior of chemical propellants suitable to support development of advanced propellants for practical applications. Recent Soviet work concentrated on solid propellants, though liquid propellants powered the largest and most advanced deployed Soviet rockets. This assessment summarizes the Soviet state of the art in chemical propellants in the late 1980s and projects the trends of that period into the next decade. It is based on a broad and deep review of Soviet literature published in 1985--1991 and is presented in an unclassified report. Speculation about or prediction of the effects of recent political and social events on chemical propellant research and development in the old Soviet Union is outside the scope of this assessment, though the effects are likely to be profound.

  9. Organic/Inorganic Hybrid Nanostructures for Chemical Plasmonic Sensors

    NASA Astrophysics Data System (ADS)

    Chang, Sehoon

    2011-12-01

    depending on the exact location and orientation of decorated silver nanoparticles nearby silver nanowire crossbars. As an alternative approach for the template-assisted nanostructure design, porous alumina membrane (PAM) can be utilized as a sacrificial template for the fabrication of the nanotube structure. The study seeks to investigate the design aspects of polymeric/inorganic hybrid nanotube structures with plasmonic properties, which can be dynamically tuned by external stimuli such as pH. This research suggests several different organic/inorganic nanostructure assemblies by various template-assisted techniques. The polymeric/inorganic hybrid nanostructures including SERS property, pH responsive characteristics, and large surface area will enable us to understand and design the novel chemical plasmonic sensors.

  10. Conservative or reactive? Mechanistic chemical perspectives on organic matter stability

    NASA Astrophysics Data System (ADS)

    Koch, Boris

    2016-04-01

    Carbon fixation by terrestrial and marine primary production has a fundamental seasonal effect on the atmospheric carbon content and it profoundly contributes to long-term carbon storage in form of organic matter (OM) in soils, water, and sediments. The efficacy of this sequestration process strongly depends on the degree of OM persistence. Therefore, one of the key issues in dissolved and particulate OM research is to assess the stability of reservoirs and to quantify their contribution to global carbon fluxes. Incubation experiments are helpful to assess OM stability during the first, early diagenetic turnover induced by sunlight or microbes. However, net carbon fluxes within the global carbon cycle also act on much longer time scales, which are not amenable in experiments. It is therefore critical to improve our mechanistic understanding to be able to assess potential future changes in the organic matter cycle. This session contribution highlights some achievements and open questions in the field. An improved mechanistic understanding of OM turnover particularly depends on the molecular characterization of biogeochemical processes and their kinetics: (i) in soils and sediments, aggregation/disaggregation of OM is primarily controlled by its molecular composition. Hence, the chemical composition determines the transfer of organic carbon from the large particulate to the small dissolved organic matter reservoir - an important substrate for microbial metabolism. (ii) In estuaries, dissolved organic carbon gradients usually suggest conservative behavior, whereas molecular-level studies reveal a substantial chemical modification of terrestrial DOM along the land-ocean interface. (iii) In the ocean, previous studies have shown that the recalcitrance of OM depends on bulk concentration and energy yield. However, ultrahigh resolution mass spectrometry in combination with radiocarbon analyses also emphasized that stability is tightly connected to molecular composition

  11. Safety in the Chemical Laboratory. Organic Peroxides.

    ERIC Educational Resources Information Center

    Shanley, Edward S.

    1990-01-01

    Discussed is the thermodynamic instability of organic peroxides. The process of autoxidation which results in peroxide formation is described. Precautions necessary to prevent autoxidation hazards associated with these reagents are suggested. (CW)

  12. Research Leadership as Entrepreneurial Organizing for Research

    ERIC Educational Resources Information Center

    Hansson, Finn; Monsted, Mette

    2008-01-01

    The paper discusses research leadership in public universities under change and the role of entrepreneurial strategies in research. Research leadership function today in situations where the New Public Management movement one the one hand have introduced management by accountability and control in the university while on the other hand open…

  13. COSOLVENT EFFECTS ON ORGANIC CHEMICAL PARTITIONING TO SEDIMENT ORGANIC CARBON

    EPA Science Inventory

    Sorption-desorption hysteresis, slow desorption kinetics and resultant bioavailability, and other nonideal phenomena have been attributed to the differing sorptive characteristics of the natural organic polymers associated with soils and sediments. The objectives of this study we...

  14. 27 CFR 478.145 - Research organizations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Research organizations. 478..., Seizures, and Forfeitures § 478.145 Research organizations. The provisions of § 478.98 with respect to the... rifles shall not apply to the sale or delivery of such devices and weapons to any research...

  15. 27 CFR 478.145 - Research organizations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Research organizations. 478..., Seizures, and Forfeitures § 478.145 Research organizations. The provisions of § 478.98 with respect to the... rifles shall not apply to the sale or delivery of such devices and weapons to any research...

  16. Chemical reactions of organic compounds on clay surfaces.

    PubMed Central

    Soma, Y; Soma, M

    1989-01-01

    Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, and the Brönsted or Lewis acidity of clay minerals. PMID:2533556

  17. Distribution of volatile organic chemicals in outdoor and indoor air

    NASA Technical Reports Server (NTRS)

    Shah, Jitendra J.; Singh, Hanwant B.

    1988-01-01

    The EPA volatile organic chemistry (VOC) national ambient data base (Shah, 1988) is discussed. The 320 chemicals included in the VOC data base are listed. The methods used to obtain the data are reviewed and the availability, accessibility, and operation of the data base are examined. Tables of the daily outdoor concentrations for 66 chemicals and the daily indoor concentrations for 35 chemicals are presented.

  18. CTEPP NC DATA ANALYTICAL RESULTS ORGANIZED BY CHEMICAL AND MEDIA

    EPA Science Inventory

    This data set contains the field sample data by chemical and matrix. The data are organized at the sample, chemical level.

    The Children’s Total Exposure to Persistent Pesticides and Other Persistent Pollutant (CTEPP) study was one of the largest aggregate exposure studies of y...

  19. Molecular Properties and Fate of Organic Chemicals

    DTIC Science & Technology

    1990-08-14

    Monsen, R.M. Water Sci. Technol. 1989, 21, ?????-????? (7) Haber, F .; Weiss, J.J. Proc. Roy. Soc. London, Ser. A 1934, 147, 332-???? (8) Lindsay Smith...366. (30) Tejedor , I., personal comm. Table 1: Products from oxidation of chlorobenzene with Fenton’s Reagent Concentrations, (mM) atmosphere Fe÷3...Complete mineralization of organic compounds was not observed dluring the oxidation o) f 4-chhorophenol is most observed because some of the ring-cleavage

  20. Organic solar cell exploratory research

    NASA Technical Reports Server (NTRS)

    Yalenty, S. J.

    1975-01-01

    Principles governing the photovoltaic effect in organic materials on the molecular level are studied and applied to the design and fabrication of laboratory devices having a photovoltaic organic polymer film as their key element. Progress to date has been in three areas: (1) materials synthesis; (2) apparatus development; and (3) ultra-thin film fabrication.

  1. Booknotes: Chemical Research Faculties: An International Directory

    NASA Astrophysics Data System (ADS)

    Kauffman, George B.

    1997-08-01

    American Chemical Society: Washington, DC, 1996. xlv + 1248 pp. 22.1x28.2 cm. ISBN 0-8412-3301-2. $199.95 (hb). This comprehensive source of information on research in chemistry and chemistry-related areas conducted by faculty members worldwide in institutions that grant advanced degrees gives the same type of information on an international scale that the ACS Directory of Graduate Research (DGR) (Kauffman, G. B. J. Chem. Educ. 1996, 73, A136) provides for United States and Canadian institutions. Designed to give users sufficient information to locate a colleague, whether known to them or not, by country, academic institution, or name, this new, updated, partially rearranged third edition of Chemical Research Faculties (CRF) contains more than an additional 75 percent of the volume of information in the second (1988) edition (Kauffman, G. B. J. Chem. Educ. 1989, 66, A48). It contains data on 17,370 faculty members (compared to 11,500 in the second edition), with one or two recent representative publications, from 2,182 institutions (compared to 1,922 in the second edition) in 113 countries arranged alphabetically from Afghanistan to Zimbabwe. A minor shortcoming compared to the last edition is the deletion of the index of faculty by research subjects, which, as a contributing editor to several journals, I found useful in locating possible referees with specific areas of expertise.

  2. Biological and chemical technologies research. FY 1995 annual summary report

    SciTech Connect

    1996-03-01

    The annual summary report presents the fiscal year (FY) 1995 research activities and accomplishments for the United States Department of Energy (DOE) Biological and Chemical Technologies Research (BCTR) Program. This BCTR program resides within the Office of Industrial Technologies (OIT) of the Office of Energy Efficiency and Renewable Energy (EE). The annual summary report for 1995 (ASR 95) contains the following: program description (including BCTR program mission statement, historical background, relevance, goals and objectives); program structure and organization, selected technical and programmatic highlights for 1995; detailed descriptions of individual projects; a listing of program output, including a bibliography of published work; patents; and awards arising from work supported by the BCTR.

  3. LANL organic analysis detection capabilities for chemical and biological warfare agents

    SciTech Connect

    Ansell, G.B.; Cournoyer, M.E.; Hollis, K.W.; Monagle, M.

    1996-12-31

    Organic analysis is the analytical arm for several Los Alamos National Laboratory (LANL) research programs and nuclear materials processes, including characterization and certification of nuclear and nonnuclear materials used in weapons, radioactive waste treatment and waste certification programs. Organic Analysis has an extensive repertoire of analytical technique within the group including headspace gas, PCBs/pesticides, volatile organics and semivolatile organic analysis. In addition organic analysis has mobile labs with analytic capabilities that include volatile organics, total petroleum hydrocarbon, PCBs, pesticides, polyaromatic hydrocarbons and high explosive screening. A natural extension of these capabilities can be applied to the detection of chemical and biological agents,

  4. CHEMICAL TRANSPORT FACILITATED BY COLLOIDAL-SIZED ORGANIC MOLECULES

    EPA Science Inventory

    The fluid passing through the pores of soils and geologic materials is not just water with dissolved inorganic chemicals, but a complex mixture of organic and inorganic molecules. Large organic molecules such as humic and fulvic materials may impact the movement of contaminants. ...

  5. Organic chemical aging mechanisms: An annotated bibliography. Waste Tank Safety Program

    SciTech Connect

    Samuels, W.D.; Camaioni, D.M.; Nelson, D.A.

    1993-09-01

    An annotated bibliography has been compiled of the potential chemical and radiological aging mechanisms of the organic constituents (non-ferrocyanide) that would likely be found in the UST at Hanford. The majority of the work that has been conducted on the aging of organic chemicals used for extraction and processing of nuclear materials has been in conjunction with the acid or PUREX type processes. At Hanford the waste being stored in the UST has been stabilized with caustic. The aging factors that were used in this work were radiolysis, hydrolysis and nitrite/nitrate oxidation. The purpose of this work was two-fold: to determine whether or not research had been or is currently being conducted on the species associated with the Hanford UST waste, either as a mixture or as individual chemicals or chemical functionalities, and to determine what areas of chemical aging need to be addressed by further research.

  6. Organic thin-film transistors for chemical and biological sensing.

    PubMed

    Lin, Peng; Yan, Feng

    2012-01-03

    Organic thin-film transistors (OTFTs) show promising applications in various chemical and biological sensors. The advantages of OTFT-based sensors include high sensitivity, low cost, easy fabrication, flexibility and biocompatibility. In this paper, we review the chemical sensors and biosensors based on two types of OTFTs, including organic field-effect transistors (OFETs) and organic electrochemical transistors (OECTs), mainly focusing on the papers published in the past 10 years. Various types of OTFT-based sensors, including pH, ion, glucose, DNA, enzyme, antibody-antigen, cell-based sensors, dopamine sensor, etc., are classified and described in the paper in sequence. The sensing mechanisms and the detection limits of the devices are described in details. It is expected that OTFTs may have more important applications in chemical and biological sensing with the development of organic electronics.

  7. 27 CFR 478.145 - Research organizations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Research organizations... Exemptions, Seizures, and Forfeitures § 478.145 Research organizations. The provisions of § 478.98 with...-barreled rifles shall not apply to the sale or delivery of such devices and weapons to any...

  8. Space research with intact organisms

    NASA Technical Reports Server (NTRS)

    Phillips, Robert W.; Haddy, Francis J.

    1992-01-01

    Effects of space exposure on intact organisms are briefly reviewed, and examples of future experiments that might provide new information on the role of gravity in the evolution of life are suggested. It is noted that long term experiments with intact plant and animals for studying gravitational thresholds will provide important new insights.

  9. Chemical Safety for Sustainability Research Action Plan 2012-2016

    EPA Pesticide Factsheets

    EPA’s Chemical Safety for Sustainability (CSS) research program presents the purpose, design and themes of the Agency’s CSS research efforts to ensure safety in the design, manufacture and use of existing and future chemicals

  10. Leadership in research: organizing genius.

    PubMed

    Slavkin, Harold

    2004-01-01

    Science has become complex. Its success is increasingly becoming a matter of collaboration based on established infrastructures and professional norms in response to environmental challenges. Leadership in such situations means organizing the genius inherent in great groups. Three examples--the Manhattan Project, mapping the human genome, and rapidly understanding the nature of the SARS virus--are analyzed, showing a trend away from the individual scientist to a model based on simultaneous competition and collaboration.

  11. From Bioavailability Science to Regulation of Organic Chemicals.

    PubMed

    Ortega-Calvo, Jose-J; Harmsen, Joop; Parsons, John R; Semple, Kirk T; Aitken, Michael D; Ajao, Charmaine; Eadsforth, Charles; Galay-Burgos, Malyka; Naidu, Ravi; Oliver, Robin; Peijnenburg, Willie J G M; Römbke, Jörg; Streck, Georg; Versonnen, Bram

    2015-09-01

    The bioavailability of organic chemicals in soil and sediment is an important area of scientific investigation for environmental scientists, although this area of study remains only partially recognized by regulators and industries working in the environmental sector. Regulators have recently started to consider bioavailability within retrospective risk assessment frameworks for organic chemicals; by doing so, realistic decision-making with regard to polluted environments can be achieved, rather than relying on the traditional approach of using total-extractable concentrations. However, implementation remains difficult because scientific developments on bioavailability are not always translated into ready-to-use approaches for regulators. Similarly, bioavailability remains largely unexplored within prospective regulatory frameworks that address the approval and regulation of organic chemicals. This article discusses bioavailability concepts and methods, as well as possible pathways for the implementation of bioavailability into risk assessment and regulation; in addition, this article offers a simple, pragmatic and justifiable approach for use within retrospective and prospective risk assessment.

  12. International energy: Research organizations, 1986--1990

    SciTech Connect

    Hendricks, P.; Jordan, S. )

    1991-03-01

    The International Energy: Research Organizations publication contains the standardized names of energy research organizations used in energy information databases. Involved in this cooperative task are (1) the technical staff of the USDOE Office of Scientific and Technical Information (OSTI) in cooperation with the member countries of the Energy Technology Data Exchange (ETDE) and (2) the International Nuclear Information System (INIS). This publication identifies current organizations doing research in all energy fields, standardizes the format for recording these organization names in bibliographic citations, assigns a numeric code to facilitate data entry, and identifies report number prefixes assigned by these organizations. These research organization names may be used in searching the databases Energy Science Technology'' on DIALOG and Energy'' on STN International. These organization names are also used in USDOE databases on the Integrated Technical Information System. Research organizations active in the past five years, as indicated by database records, were identified to form this publication. This directory includes approximately 34,000 organizations that reported energy-related literature from 1986 to 1990 and updates the DOE Energy Data Base: Corporate Author Entries.

  13. Chemical Characterization of Organisms Isolated from Leprosy Patients

    PubMed Central

    Beaman, Blain L.; Kim, Kwang-Shin; Lanéelle, Marie A.; Barksdale, Lane

    1974-01-01

    Chemical analyses of the cell walls of organisms isolated in various parts of the world from cases of lepromatous and tuberculoid leprosy make possible their assignment to one of the three genera: Corynebacterium, Mycobacterium, or Propionibacterium. One, bacterium 22M, remains unassigned. The combined chemical and enzymatic properties attributed to leprosy bacilli freshly harvested from lepromata are found collectively, but not individually, in these three genera. Images PMID:4813897

  14. Introduction: Self-organization in nonequilibrium chemical systems.

    PubMed

    Epstein, Irving R; Pojman, John A; Steinbock, Oliver

    2006-09-01

    The field of self-organization in nonequilibrium chemical systems comprises the study of dynamical phenomena in chemically reacting systems far from equilibrium. Systematic exploration of this area began with investigations of the temporal behavior of the Belousov-Zhabotinsky oscillating reaction, discovered accidentally in the former Soviet Union in the 1950s. The field soon advanced into chemical waves in excitable media and propagating fronts. With the systematic design of oscillating reactions in the 1980s and the discovery of Turing patterns in the 1990s, the scope of these studies expanded dramatically. The articles in this Focus Issue provide an overview of the development and current state of the field.

  15. Encoding of Fundamental Chemical Entities of Organic Reactivity Interest using chemical ontology and XML.

    PubMed

    Durairaj, Vijayasarathi; Punnaivanam, Sankar

    2015-09-01

    Fundamental chemical entities are identified in the context of organic reactivity and classified as appropriate concept classes namely ElectronEntity, AtomEntity, AtomGroupEntity, FunctionalGroupEntity and MolecularEntity. The entity classes and their subclasses are organized into a chemical ontology named "ChemEnt" for the purpose of assertion, restriction and modification of properties through entity relations. Individual instances of entity classes are defined and encoded as a library of chemical entities in XML. The instances of entity classes are distinguished with a unique notation and identification values in order to map them with the ontology definitions. A model GUI named Entity Table is created to view graphical representations of all the entity instances. The detection of chemical entities in chemical structures is achieved through suitable algorithms. The possibility of asserting properties to the entities at different levels and the mechanism of property flow within the hierarchical entity levels is outlined.

  16. Predicting the bioconcentration factor of highly hydrophobic organic chemicals.

    PubMed

    Garg, Rajni; Smith, Carr J

    2014-07-01

    Bioconcentration refers to the process of uptake and buildup of chemicals in living organisms. Experimental measurement of bioconcentration factor (BCF) is time-consuming and expensive, and is not feasible for a large number of chemicals of regulatory concern. Quantitative structure-activity relationship (QSAR) models are used for estimating BCF values to help in risk assessment of a chemical. This paper presents the results of a QSAR study conducted to address an important problem encountered in the prediction of the BCF of highly hydrophobic chemicals. A new QSAR model is derived using a dataset of diverse organic chemicals previously tested in a United States Environmental Protection Agency laboratory. It is noted that the linear relationship between the BCF and hydrophobic parameter, i.e., calculated octanol-water partition coefficient (ClogP), breaks down for highly hydrophobic chemicals. The parabolic QSAR equation, log BCF=3.036 ClogP-0.197 ClogP(2)-0.808 MgVol (n=28, r(2)=0.817, q(2)=0.761, s=0.558) (experimental log BCF range=0.44-5.29, ClogP range=3.16-11.27), suggests that a non-linear relationship between BCF and the hydrophobic parameter, along with inclusion of additional molecular size, weight and/or volume parameters, should be considered while developing a QSAR model for more reliable prediction of the BCF of highly hydrophobic chemicals.

  17. Chemical research projects office: An overview and bibliography, 1975-1980

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Heimbuch, A. H.; Parker, J. A.

    1980-01-01

    The activities of the Chemical Research Projects Office at Ames Research Center, Moffett Field, California are reported. The office conducts basic and applied research in the fields of polymer chemistry, computational chemistry, polymer physics, and physical and organic chemistry. It works to identify the chemical research and technology required for solutions to problems of national urgency, synchronous with the aeronautic and space effort. It conducts interdisciplinary research on chemical problems, mainly in areas of macromolecular science and fire research. The office also acts as liaison with the engineering community and assures that relevant technology is made available to other NASA centers, agencies, and industry. Recent accomplishments are listed in this report. Activities of the three research groups, Polymer Research, Aircraft Operating and Safety, and Engineering Testing, are summarized. A complete bibliography which lists all Chemical Research Projects Office publications, contracts, grants, patents, and presentations from 1975 to 1980 is included.

  18. Target organs in chronic bioassays of 533 chemical carcinogens.

    PubMed Central

    Gold, L S; Slone, T H; Manley, N B; Bernstein, L

    1991-01-01

    A compendium of carcinogenesis bioassay results organized by target organ is presented for 533 chemicals that are carcinogenic in at least one species. This compendium is based primarily on experiments in rats or mice; results in hamsters, nonhuman primates, and dogs are also reported. The compendium can be used to identify chemicals that induce tumors at particular sites, and to determine whether target sites are the same for chemicals positive in more than one species. The Carcinogenic Potency Database (CPDB), which includes results of 3969 experiments, is used in the analysis. The published CPDB includes details on each test, and literature references. Chemical carcinogens are reported for 35 different target organs in rats or mice. More than 80% of the carcinogens in each of these species are positive in at least one of the 8 most frequent target sites: liver, lung, mammary gland, stomach, vascular system, kidney, hematopoietic system, and urinary bladder. An analysis is presented of how well one can predict the carcinogenic response in mice from results in rats, or vice versa. Among chemicals tested in both species, 76% of rat carcinogens are positive in mice, and 71% of mouse carcinogens are positive in rats. Prediction is less accurate to the same target site: 52% of rat carcinogens are positive in the same site in mice, and 48% of mouse carcinogens are positive in the same site in rats. The liver is the most frequent site in common between rats and mice. PMID:1773795

  19. In Situ Chemical Reduction for Organic Explosives in Soil

    DTIC Science & Technology

    2009-05-01

    Amendment • Combines solid controlled-release carbon and nutrients (aerobic) or with micro-scale ZVI (anaerobic) • Stimulates indigenous bacteria by...herbicides • organic explosives • chlorinated solvents Aerobic • wood treatment chemicals ( PAHs & PCP) • manufactured gas plant PAHs • phthalates

  20. Dynamic exposure of organisms and passive samplers to hydrophobic chemicals.

    PubMed

    Bayen, Stéphane; Ter Laak, Thomas L; Buffle, Jacques; Hermens, Joop L M

    2009-04-01

    An insight into the dynamic aspects of the accumulation process is essential for understanding bioaccumulation as well as effect studies of hydrophobic organic chemicals. This review presents an overview of kinetic studies with organisms (fish, bivalve, crustacean, insect, worm, algae, and protozoan) as well as passive samplers (solid and liquid phase microextraction, semipermeable membrane device, polymer sheet, solid-phase extraction, Chemcatcher, etc.) for the uptake of neutral nonpolar chemicals from the aqueous phase. Information about uptake rates, elimination rates, and 95% equilibration times was collected and analyzed with diffusion based models. The present literature review suggests that the surface to volume ratio appears to be a critical parameter for the uptake rate of the more hydrophobic chemicals both for samplers and organisms. In addition, as a very first approximation, the combination of the first-order kinetic model with the assumption that diffusion through the aqueous boundary layers is rate limiting, gives a reasonable description of the experimental kinetic data. In this way, the presented model might be used to estimate uptake and elimination rate constants of chemicals by organisms or passive samplers.

  1. The first decade of organic spintronics research.

    PubMed

    Sun, Dali; Ehrenfreund, Eitan; Vardeny, Z Valy

    2014-02-21

    The first decade of organic spintronics research has benefitted from the analogy and previous experience of the inorganic spintronics field, coupled with the unlimited versatility of organic materials synthesis. At the same time, the field of organic spintronics has developed into an attractive and promising field of its own, with rich physics and promising unique potential applications. We review here a set of significant milestones achieved in organic spintronic devices such as organic spin valves, bipolar spin-valves, and hybrid organic/inorganic light emitting diodes in comparison with representative inorganic spintronic devices. We also point out acute problems that need to be resolved before the young field of organic spintronics can mature.

  2. Rapid Chemical Exposure and Dose Research

    EPA Pesticide Factsheets

    EPA evaluates the potential risks of the manufacture and use of thousands of chemicals. To assist with this evaluation, EPA scientists developed a rapid, automated model using off the shelf technology that predicts exposures for thousands of chemicals.

  3. Chemical Research Projects Office: Functions, accomplishments, and programs

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.

    1972-01-01

    The purpose, technical accomplishments, and related activities of the Chemical Research Project Group are outlined. Data cover efforts made to: (1) identify chemical research and technology required for solutions to problems of national urgency, synchronous with aeronautics and space effort; (2) conduct basic and applied interdisciplinary research on chemical problems in the areas of macromolecular science and fire research, and (3) provide productive liason with the engineering community and effective transfer of technology to other agencies and industry.

  4. 40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... organic chemicals subcategory. 414.70 Section 414.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Bulk Organic Chemicals § 414.70 Applicability; description of the bulk organic chemicals...

  5. 40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... organic chemicals subcategory. 414.70 Section 414.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Bulk Organic Chemicals § 414.70 Applicability; description of the bulk organic chemicals...

  6. 40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... organic chemicals subcategory. 414.70 Section 414.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Bulk Organic Chemicals § 414.70 Applicability; description of the bulk organic chemicals...

  7. 40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... organic chemicals subcategory. 414.70 Section 414.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Bulk Organic Chemicals § 414.70 Applicability; description of the bulk organic chemicals...

  8. Approaches to Establishing the Chemical Structure of Extraterrestrial Organic Solids

    NASA Technical Reports Server (NTRS)

    Cody, G. D.; Alexander, C. M. OD.; Wirick, Susan

    2003-01-01

    The majority of extraterrestrial organic matter in carbonaceous chondrites resides in a chemically complex, insoluble and perhaps macromolecular phase. We have been applying a series of independent solid state NMR experiments that are designed to provide a self consistent chemical characterization of this complex material. To date we have thoroughly analyzed 8 organic residues from different meteorites, including a CR2 (EET92042), CIl(Orgueil), CM2 (Murchison), Tagish Lake, CM2 (AlH83100), CM2 (Cold Bokkefeld), CM2 (Mighei), CM3 (Y86720). In fig 1. (1)H to (13)C cross polarization NMR spectra of four of these are shown. Note that there exists an enormous range in chemistry exhibited in organic solid [evident by the breadth of the spectral features both in the aliphatic region (sp(sup 3)) and the aromatic region (sp(sup 2))]. There is also considerable differences in the carbon chemistry across the meteorite groups.

  9. Metal Organic-Chemical Vapor Deposition fabrication of semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Thomas, C.

    1980-08-01

    The metal organic chemical vapor deposition (MO-CVD) process was studied and implemented in detail. Single crystal GaAs, and Ga(x)Al(1-x)As films were grown on GaAs by depositing metal organic alkyl gallium compounds in the presence of an arsine mixture. The metal organic chemical vapor deposition process allowed formation of the semiconductor compound directly on the heated substrate in only one hot temperature zone. With MO-CVD, semiconductor films can be efficiently produced by a more economical, less complicated process which will lend itself more easily than past fabrication procedures, to high quantity, high quality reproduction techniques of semiconductor lasers. Clearly MO-CVD is of interest to the communication industry where semiconductor lasers are used extensively in fiber optic communication systems, and similarly to the solar energy business where GaAs substrates are used as photoelectric cells.

  10. Optical Detection of Organic Chemical Biosignatures at Hydrothermal Vents

    NASA Technical Reports Server (NTRS)

    Conrad, P. G.; Lane, A. L.; Bhartia, R.; Hug, W. H.

    2004-01-01

    We have developed a non-contact, optical life detection instrument that can detect organic chemical biosignatures in a number of different environments, including dry land, shallow aqueous, deep marine or in ice. Hence, the instrument is appropriate as a biosignature survey tool both for Mars exploration or in situ experiments in an ice-covered ocean such as one might wish to explore on Europa. Here, we report the results we obtained on an expedition aboard the Russian oceanographic vessel Akademik Mstislav Keldysh to hydrothermal vent sites in the Pacific Ocean using our life detection instrument MCDUVE, a multichannel, deep ultraviolet excitation fluorescence detector. MCDUVE detected organic material distribution on rocks near the vent, as well as direct detection of organisms, both microbial and microscopic. We also were able to detect organic material issuing directly from vent chimneys, measure the organic signature of the water column as we ascended, and passively observe the emission of light directly from some vents.

  11. INFLUENCE OF ORGANIC COSOLVENTS ON THE SORPTION KINETICS OF HYDROPHOBIC ORGANIC CHEMICALS

    EPA Science Inventory

    A quantitative examination of the kinetics of sorption of hydrophobic organic chemicals by soils from mixed solvents reveals that the reverse sorption rate constant (k2) increases log-linearly with increasing volume fraction of organic cosolvent (fc). This relationship was expec...

  12. Volatile Organic Compounds (VOCs) and Elevated Concentrations of Carbon Dioxide (CO2) in Unsaturated-Zone Vapors Near a Chemical and Low-Level Radioactivity Waste-Disposal Facility, Amargosa Desert Research Site, Nye County, Nevada

    NASA Astrophysics Data System (ADS)

    Baker, R. J.; Andraski, B. J.; Walvoord, M. A.; Stonestrom, D. A.; Prudic, D. E.; Luo, W.

    2003-12-01

    As part of its Toxic Substances Hydrology Program, the U.S. Geological Survey is studying contaminant-transport processes in an arid environment at the Amargosa Desert Research Site (http://nevada.usgs.gov/adrs/). The site is near waste-disposal facilities 20 kilometers east of Death Valley National Park. Low-level radioactive waste was buried in unlined trenches of varying depth during 1962-92. Hazardous chemical waste was buried in unlined trenches at an adjacent facility during 1970-88. Mean annual precipitation at the site from 1981 to 2000 was 108 millimeters. The unsaturated zone is aerobic down to the water table, which is about 110 m (meters) deep. Sampling infrastructure south and west of the facility includes a grid of vapor probes 1.5 m deep, a 23.8-m-deep background borehole (JFDB), and two approximately 100-m-deep boreholes (UZB-2 and UZB-3), which are 160 m and 100 m from the nearest trench, respectively, and are instrumented for multi-level sampling. Analytes detected in unsaturated-zone-vapor samples include elevated concentrations of tritium and carbon-14; three chlorofluorocarbon (CFC) compounds, eight chlorinated solvent compounds, and toluene, all at concentrations exceeding 1,000 parts per billion (ppb) in UZB-3, and at lower concentrations in UZB-2 and in the shallow-vapor-probe grid; and CO2 in concentrations up to 2% in UZB-3, whereas maximum CO2 concentrations in JFDB are less than 0.2%. With the notable exception of toluene, VOCs that are known to be highly biodegradable are generally absent or occur at low concentrations (<100 ppb). The trends in the CO2 concentration profiles approximately parallel those of CFCs and radionuclides. The following preliminary conclusions have been drawn from the radionuclide, VOC, and CO2 data: 1. Biodegradation of organic substances is a reasonable explanation for the presence of CO2 in UZB-3 at concentrations greater those in JFDB (background), which are attributed to near-surface natural biological

  13. Role of chemical and ecological factors in trophic transfer of organic chemicals in aquatic food webs

    SciTech Connect

    Russell, R.W.; Gobas, F.A.P.C. . School of Resource and Environmental Management); Haffner, G.D. )

    1999-06-01

    Trophic transfer of chlorinated organic contaminants was investigated in an aquatic community composed of zooplankton, benthic invertebrates, and fish. Biomagnification, measured as the increase in lipid-based chemical concentrations in predator over that in prey, was observed for high-K[sub OW] chemicals (log K[sub OW] > 6.3). Low-K[sub OW] chemicals (log K[sub OW] < 5.5) did not biomagnify in the food web, and chemicals with log K[sub OW] between 5.5 and 6.3 showed some evidence of biomagnification. Trophic level differences in chemical accumulation in the food web could not be attributed to bioconcentration into increasing trophic levels with increasing lipid levels, as no relationship was observed between trophic position and lipid content of organisms. Plots of contaminant-ordinated principal component scores in component space predicted the detailed diets of the species examined. It is concluded that (1) trophic interactions play a crucial role in the distribution of high-K[sub OW] chemicals but not for low-K[sub OW] chemicals and that (2) contaminant distributions provide a means to determine structure in aquatic communities.

  14. BCTR: Biological and Chemical Technologies Research 1994 annual summary report

    SciTech Connect

    Petersen, G.

    1995-02-01

    The annual summary report presents the fiscal year (FY) 1994 research activities and accomplishments for the United States Department of Energy (DOE) Biological and Chemical Technologies Research (BCTR) Program of the Advanced Industrial Concepts Division (AICD). This AICD program resides within the Office of Industrial Technologies (OIT) of the Office of Energy Efficiency and Renewable Energy (EE). Although the OIT was reorganized in 1991 and AICD no longer exists, this document reports on efforts conducted under the former structure. The annual summary report for 1994 (ASR 94) contains the following: program description (including BCTR program mission statement, historical background, relevance, goals and objectives); program structure and organization, selected technical and programmatic highlights for 1994; detailed descriptions of individual projects; a listing of program output, including a bibliography of published work; patents, and awards arising from work supported by BCTR.

  15. Beyond Chemical Literature: Developing Skills for Chemical Research Literacy

    ERIC Educational Resources Information Center

    Jensen, Dell, Jr.; Narske, Richard; Ghinazzi, Connie

    2010-01-01

    With the growing availability of electronic databases, online journal publications, and open-access publishing, there is unprecedented access to research materials. Increasingly, these materials are being incorporated into chemistry curricula and being used by undergraduate students in literature research. Internet savvy students can effectively…

  16. Chemical evolution and the preservation of organic compounds on Mars

    NASA Technical Reports Server (NTRS)

    Kanavarioti, Anastassia; Mancinelli, Rocco L.

    1989-01-01

    Several lines of evidence suggest that the environment on early Mars and early Earth were very similar. Since life is abundant on Earth, it seems likely that conditions on early Earth were conducive to chemical evolution and the origin of life. The similarity between early Mars and early Earth encourages the hypothesis that chemical evolution might have also occurred on Mars, but that decreasing temperatures and the loss of its atmosphere brought the evolution to a halt. The possibility of finding on Mars remnants of organic material dating back to this early clement period is addressed.

  17. Destruction of chemical warfare agents using metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Mondloch, Joseph E.; Katz, Michael J.; Isley, William C., III; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W.; Hall, Morgan G.; Decoste, Jared B.; Peterson, Gregory W.; Snurr, Randall Q.; Cramer, Christopher J.; Hupp, Joseph T.; Farha, Omar K.

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic ZrIV ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  18. Destruction of chemical warfare agents using metal-organic frameworks.

    PubMed

    Mondloch, Joseph E; Katz, Michael J; Isley, William C; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W; Hall, Morgan G; DeCoste, Jared B; Peterson, Gregory W; Snurr, Randall Q; Cramer, Christopher J; Hupp, Joseph T; Farha, Omar K

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic Zr(IV) ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  19. Application of the Activity Framework for Assessing Aquatic Ecotoxicology Data for Organic Chemicals.

    PubMed

    Thomas, Paul; Dawick, James; Lampi, Mark; Lemaire, Philippe; Presow, Shaun; van Egmond, Roger; Arnot, Jon A; Mackay, Donald; Mayer, Philipp; Galay Burgos, Malyka

    2015-10-20

    Toxicological research in the 1930s gave the first indications of the link between narcotic toxicity and the chemical activity of organic chemicals. More recently, chemical activity has been proposed as a novel exposure parameter that describes the fraction of saturation and that quantifies the potential for partitioning and diffusive uptake. In the present study, more than 2000 acute and chronic algal, aquatic invertebrates and fish toxicity data, as well as water solubility and melting point values, were collected from a series of sources. The data were critically reviewed and grouped by mode of action (MoA). We considered 660 toxicity data to be of acceptable quality. The 328 data which applied to the 72 substances identified as MoA 1 were then evaluated within the activity-toxicity framework: EC50 and LC50 values for all three taxa correlated generally well with (subcooled) liquid solubilities. Acute toxicity was typically exerted within the chemical activity range of 0.01-0.1, whereas chronic toxicity was exerted in the range of 0.001-0.01. These results confirm that chemical activity has the potential to contribute to the determination, interpretation and prediction of toxicity to aquatic organisms. It also has the potential to enhance regulation of organic chemicals by linking results from laboratory tests, monitoring and modeling programs. The framework can provide an additional line of evidence for assessing aquatic toxicity, for improving the design of toxicity tests, reducing animal usage and addressing chemical mixtures.

  20. Gas uptake and chemical aging of semisolid organic aerosol particles.

    PubMed

    Shiraiwa, Manabu; Ammann, Markus; Koop, Thomas; Pöschl, Ulrich

    2011-07-05

    Organic substances can adopt an amorphous solid or semisolid state, influencing the rate of heterogeneous reactions and multiphase processes in atmospheric aerosols. Here we demonstrate how molecular diffusion in the condensed phase affects the gas uptake and chemical transformation of semisolid organic particles. Flow tube experiments show that the ozone uptake and oxidative aging of amorphous protein is kinetically limited by bulk diffusion. The reactive gas uptake exhibits a pronounced increase with relative humidity, which can be explained by a decrease of viscosity and increase of diffusivity due to hygroscopic water uptake transforming the amorphous organic matrix from a glassy to a semisolid state (moisture-induced phase transition). The reaction rate depends on the condensed phase diffusion coefficients of both the oxidant and the organic reactant molecules, which can be described by a kinetic multilayer flux model but not by the traditional resistor model approach of multiphase chemistry. The chemical lifetime of reactive compounds in atmospheric particles can increase from seconds to days as the rate of diffusion in semisolid phases can decrease by multiple orders of magnitude in response to low temperature or low relative humidity. The findings demonstrate that the occurrence and properties of amorphous semisolid phases challenge traditional views and require advanced formalisms for the description of organic particle formation and transformation in atmospheric models of aerosol effects on air quality, public health, and climate.

  1. Unraveling the chemical space of terrestrial and meteoritic organic matter

    NASA Astrophysics Data System (ADS)

    Schmitt-Kopplin, Philippe; Harir, Mourad; Hertkorn, Norbert; Kanawati, Basem; Ruf, Alexander; Quirico, Eric; Bonal, Lydie; Beck, Pierre; Gabelica, Zelimir

    2015-04-01

    In terrestrial environments natural organic matter (NOM) occurs in soils, freshwater and marine environments, in the atmosphere and represents an exceedingly complex mixture of organic compounds that collectively exhibits a nearly continuous range of properties (size-reactivity continuum). In these materials, the "classical" biogeosignatures of the (biogenic and geogenic) precursor molecules, like lipids, lignins, proteins and natural products have been attenuated, often beyond recognition, during a succession of biotic and abiotic (e.g. photo- and redox chemistry) reactions. Because of this loss of biochemical signature, these materials can be designated non-repetitive complex systems. The access to extra-terrestrial organic matter is given i.e. in the analysis of meteoritic materials. Numerous descriptions of organic molecules present in organic chondrites have improved our understanding of the early interstellar chemistry that operated at or just before the birth of our solar system. However, many molecular analyses are so far targeted toward selected classes of compounds with a particular emphasis on biologically active components in the context of prebiotic chemistry. Here we demonstrate that a non-targeted ultrahigh-resolution molecular analysis of the solvent-accessible organic fraction of meteorite extracted under mild conditions allows one to extend its indigenous chemical diversity to tens of thousands of different molecular compositions and likely millions of diverse structures. The description of the molecular complexity provides hints on heteroatoms chronological assembly, shock and thermal events and revealed recently new classes of thousands of novel organic, organometallic compounds uniquely found in extra-terrestrial materials and never described in terrestrial systems. This high polymolecularity suggests that the extraterrestrial chemodiversity is high compared to terrestrial relevant biological and biogeochemical-driven chemical space. (ultra

  2. Influence of Organic Chemicals on Water Molecule Bridges in Soil Organic Matter of a Sapric Histosol.

    PubMed

    Ondruch, Pavel; Kučerík, Jiri; Steinmetz, Zacharias; Schaumann, Gabriele E

    2017-03-02

    Water molecules in soil organic matter (SOM) can form clusters bridging neighboring molecular segments (water molecule bridges; WaMB). WaMB are hypothesized to enhance physical entrapment of organic chemicals and to control the rigidity of the SOM supramolecular structure. However, the understanding of WaMB dynamics in SOM is still limited. We investigated the relation between WaMB stability and the physicochemical properties of their environment by treating a sapric histosol with various solvents and organic chemicals. Based on predictions from molecular modeling, we hypothesized that the stability of WaMB, measured by differential scanning calorimetry, increases with decreasing ability of a chemical to interact with water molecules of the WaMB. The interaction ability between WaMB and the chemicals was characterized by linear solvation energy relationships. WaMB stability in solvent-treated samples was found to decrease with increasing ability of a solvent to undergo H-donor/acceptor interactions. Spiking with an organic chemical stabilized (naphthalene) or destabilized (phenol) the WaMB. WaMB stability and matrix rigidity were generally reduced strongly and fast when hydrophilic chemicals entered the soil. The physicochemical aging following this destabilization is slow, but leads to a successive WaMB stabilization and matrix stiffening.

  3. Space research on organs and tissues

    NASA Technical Reports Server (NTRS)

    Tischler, Marc E.; Morey-Holton, Emily

    1992-01-01

    The effects of microgravity on various physiological systems are reviewed focusing on muscle, bone, cardiovascular, pulmonary, neurovestibular, liver, and endocrine systems. It is noted that certain alterations of organs and tissues caused by microgravity are not reproducible in earth-bound animal or human models. Thus space research on organs and tissues is essential for both validating the earth-bound models used in laboratories and studying the adaptations to weightlessness which cannot be mimicked on earth.

  4. Chemical laser exhaust pipe design research

    NASA Astrophysics Data System (ADS)

    Sun, Yunqiang; Huang, Zhilong; Chen, Zhiqiang; Ren, Zebin; Guo, Longde

    2016-10-01

    In order to weaken the chemical laser exhaust gas influence of the optical transmission, a vent pipe is advised to emissions gas to the outside of the optical transmission area. Based on a variety of exhaust pipe design, a flow field characteristic of the pipe is carried out by numerical simulation and analysis in detail. The research results show that for uniform deflating exhaust pipe, although the pipeline structure is cyclical and convenient for engineering implementation, but there is a phenomenon of air reflows at the pipeline entrance slit which can be deduced from the numerical simulation results. So, this type of pipeline structure does not guarantee seal. For the design scheme of putting the pipeline contract part at the end of the exhaust pipe, or using the method of local area or tail contraction, numerical simulation results show that backflow phenomenon still exists at the pipeline entrance slit. Preliminary analysis indicates that the contraction of pipe would result in higher static pressure near the wall for the low speed flow field, so as to produce counter pressure gradient at the entrance slit. In order to eliminate backflow phenomenon at the pipe entrance slit, concerned with the pipeline type of radial size increase gradually along the flow, flow field property in the pipe is analyzed in detail by numerical simulation methods. Numerical simulation results indicate that there is not reflow phenomenon at entrance slit of the dilated duct. However the cold air inhaled in the slit which makes the temperature of the channel wall is lower than the center temperature. Therefore, this kind of pipeline structure can not only prevent the leak of the gas, but also reduce the wall temperature. In addition, compared with the straight pipe connection way, dilated pipe structure also has periodic structure, which can facilitate system integration installation.

  5. Identification and chemical characterization of specific organic indicators in the effluents from chemical production sites.

    PubMed

    Botalova, Oxana; Schwarzbauer, Jan; al Sandouk, Nadia

    2011-06-01

    The structural diversity of the wastewater composition was described by the use of detailed non-target screening analyses of industrial effluents from chemical production sites. Determination of the indicative organic compounds acting as potential molecular indicators for industrial emissions from chemical production industries has been possible due to (i) detailed characterisation of industrial contaminants and identification of compounds with high source specificity, (ii) quantitative determination of the organic constituents in the industrial effluents and (iii) the review of their industrial applications. The determination of potential site-specific markers and industrial molecular indicators corresponding to certain production processes (production of starting materials for manufacturing paper and printing inks, powder coatings as well as epichlorohydrin production) was performed in this work. The results of this study allowed significant contributions to the chemical characterisation of industrial contaminants and isolation of indicators that can act as representatives of industrial effluents in the aquatic environment.

  6. Apparatus for sensing volatile organic chemicals in fluids

    DOEpatents

    Hughes, Robert C.; Manginell, Ronald P.; Jenkins, Mark W.; Kottenstette, Richard; Patel, Sanjay V.

    2005-06-07

    A chemical-sensing apparatus is formed from the combination of a chemical preconcentrator which sorbs and concentrates particular volatile organic chemicals (VOCs) and one or more chemiresistors that sense the VOCs after the preconcentrator has been triggered to release them in concentrated form. Use of the preconcentrator and chemiresistor(s) in combination allows the VOCs to be detected at lower concentration than would be possible using the chemiresistor(s) alone and further allows measurements to be made in a variety of fluids, including liquids (e.g. groundwater). Additionally, the apparatus provides a new mode of operation for sensing VOCs based on the measurement of decay time constants, and a method for background correction to improve measurement precision.

  7. Organization of an undergraduate research group

    SciTech Connect

    Hill, J.; Noteboom, E.

    1995-04-01

    Traditionally, research groups consist of senior physicists, staff members, and graduate students. The physics department at Creighton University has formed a Relativistic Heavy Ion physics research group consisting primarily of undergraduate students. Although senior staff and graduate students are actively involved, undergraduate research and the education of undergraduates is the focus of the group. The presentation, given by two undergraduate members of the group, will outline progress made in the group`s organization, discuss the benefits to the undergraduate group members, and speak to the balance which must be struck between education concerns and research goals.

  8. Fan organs of crayfish enhance chemical information flow.

    PubMed

    Breithaupt, T

    2001-04-01

    Animals as well as autonomous robots need to acquire environmental signals in order to adjust their activity in time and space. Some information is accessible to the sensors only as a result of specific behaviors for stimulus acquisition. Due to the slow rate of molecular diffusion, dispersal of chemical stimuli depends on fluid flow. Aquatic crustaceans can generate directed water currents by specialized appendages. Here I describe the crayfish fan organs, which are feathered flagella of the mouthparts, and their activity in sending and receiving chemical signals in environments with stagnant flow conditions. During the power-stroke, the fan opens and displaces water; during the return stroke, it collapses and thereby minimizes drag. These organs can create a variety of flow fields including water jets, and in many different directions. Bilateral upward fanning draws water horizontally from all directions toward the anterior chemoreceptors. Unilateral upward fanning draws water from only one side towards the body. The versatility of the crayfish fan organ makes it a candidate for biomimetic reconstruction and use in autonomous robots that can search chemical sources.

  9. Recent advances in organ microcirculation research.

    PubMed

    Tsuchiya, M; Oda, M

    1987-01-01

    This review article dealt with progress in the research of gastroenterological organ microcirculation in Japan. It must be emphasized that this remarkable progress particularly in intravital microcirculatory observations at organ level is attributable to great improvement of microscopic devices combined with computerized system, development of new techniques for measuring microcirculatory blood flow and pioneering of a variety of fluorescent and isotope-labelled tracers. Little attention has been directed toward the fact that microvascular manifestations are perhaps the earliest signs of "cells and tissues" dysfunction in disease processes. The microvasculature undergoes a substantial remodeling not only in vascular wall structures, but also in network characteristics themselves especially in chronic disease. Those microvascular alterations in an organ system, which primarily originate in adaptations to the microenvironmental changes, would lead to the chronicity and self-perpetuation of disease. As has been noted in the IVth World Congress for Microcirculation organized by the Japanese Society for Microcirculation, which was held in Tokyo, July 26-30, 1987, further progress has been made in the research of organ microcirculation in the gastroenterological and other fields. It is the cornerstone for better understanding of the pathogenesis of organ diseases to clarify the earliest alterations in the microvasculature of an organ system from a combined aspect of microhemo- and microlymphocirculation using the newly developed techniques for microcirculation study.

  10. 40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of...) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory. The provisions of...

  11. 40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of...) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory. The provisions of...

  12. 40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of...) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory. The provisions of...

  13. Summaries of FY 1980 research in the chemical sciences

    SciTech Connect

    1980-09-01

    Brief summaries are given of research programs being pursued by DOE laboratories and offsite facilities in the fields of photochemical and radiation sciences, chemical physics, atomic physics, chemical energy, separations, analysis, and chemical engineering sciences. No actual data is given. Indexes of topics, offsite institutions, and investigators are included. (DLC)

  14. Self-organized nanoporous materials for chemical separations and chemical sensing

    NASA Astrophysics Data System (ADS)

    Pandey, Bipin

    Self-organized nanoporous materials have drawn a lot of attention because the uniform, highly dense, and ordered cylindrical nanopores in these materials provide a unique platform for chemical separations and chemical sensing applications. Here, we explore self-organized nanopores of PS-b-PMMA diblock copolymer thin films and anodic gallium oxide for chemical separations and sensing applications. In the first study, cyclic voltammograms of cytochrome c on recessed nanodisk-array electrodes (RNEs) based on nanoporous films (11, 14 or 24 nm in average pore diameter; 30 nm thick) derived from polystyrene-poly(methylmethacrylate) diblock copolymers were measured. The faradic current of cytochrome c was observed on RNEs, indicating the penetration of cytochrome c (hydrodynamic diameter ≈ 4 nm) through the nanopores to the underlying electrodes. Compared to the 24-nm pores, the diffusion of cytochrome c molecules through the 11- and 14-nm pores suffered significantly larger hindrance. The results reported in this study will provide guidance in designing RNEs for size-based chemical sensing and also for controlled immobilization of biomolecules within nanoporous media for biosensors and bioreactors. In another study, conditions for the formation of self-organized nanopores of a metal oxide film were investigated. Self-organized nanopores aligned perpendicular to the film surface were obtained upon anodization of gallium films in ice-cooled 4 and 6 M aqueous H2SO4 at 10 V and 15 V. The average pore diameter was in the range of 18 ~ 40 nm, and the anodic gallium oxide was ca. 2 microm thick. In addition, anodic formation of self-organized nanopores was demonstrated for a solid gallium monolith incorporated at the end of a glass capillary. Nanoporous anodic oxide monoliths formed from a fusible metal will lead to future development of unique devices for chemical sensing and catalysis. In the final study, surface chemical property of self-organized nanoporous anodic gallium

  15. 40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic...

  16. 40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic...

  17. 40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic...

  18. 40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic...

  19. 40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic...

  20. 40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic...

  1. 40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic...

  2. 40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic...

  3. 40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic...

  4. 40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic...

  5. Chemical alteration of extraterrestrial organics during atmospheric entry of micrometeorites

    NASA Astrophysics Data System (ADS)

    Kress, M.; Brownlee, D.

    Most of the extraterrestrial carbon accreted by Earth is carried by the 40,000 tons of ~0.2 mm micrometeorites that enter the atmosphere every year. Particles in this size range would have supplied an enormous amount of carbon to the inchoate biosphere since the exogenous influx at ~4 Ga would have been much higher than today. However, these particles undergo strong drag heating to ~1500 K for several seconds upon atmospheric entry, ostensibly burning away all the organics as CO. Ironically, particles of this size seemed to contribute no organic carbon to Earth despite the fact that they constitute the bulk of the total incoming mass. Conventional wisdom has thus held that organics survive only in smaller cosmic dust grains and in >~cm-sized meteorites, which account for only a tiny fraction of the total exogenous mass flux. However, carbon has been found in several smaller, yet still strongly-heated particles in the form of a refractory, char-like material imbedded with tiny FeNi metal beads, motivating us to study the pyrolysis of complex organic matter. We will present results from experiments and chemical models of the transient drag heating of micrometeorites. We predict that small aromatics, light hydrocarbons, and other organics, as well as CO and char, are formed, indicating that strongly-heated micrometeorites may have indeed been a significant source of organic carbon during the origin of life on Earth.

  6. Research in the chemical sciences: Summaries of FY 1994

    SciTech Connect

    Not Available

    1994-12-01

    This summary book is published annually on research supported by DOE`s Division of Chemical Sciences in the Office of Energy Research. Research in photochemical and radiation sciences, chemical physics, atomic physics, chemical energy, separations and analysis, heavy element chemistry, chemical engineering sciences, and advanced batteries is arranged according to national laboratories, offsite institutions, and small businesses. Goal is to add to the knowledge base on which existing and future efficient and safe energy technologies can evolve. The special facilities used in DOE laboratories are described. Indexes are provided (topics, institution, investigator).

  7. Evaluating Capacity Building for Policy Research Organizations

    ERIC Educational Resources Information Center

    Struyk, Raymond J.; Damon, Mawadda; Haddaway, Samuel R.

    2011-01-01

    The international community has identified a positive link between good governance and economic development. There is an increasing appreciation of the effective role that local policy research organizations (PROs) can play in providing evidence-based policy recommendations as the basis for sound legislation and in assessing the efficacy of…

  8. Summaries of FY 1993 research in the chemical sciences

    SciTech Connect

    Not Available

    1993-08-01

    The summaries in photochemical and radiation sciences, chemical physics, atomic physics, chemical energy, separations and analysis, heavy element chemistry, chemical engineering sciences, and advanced battery technology are arranged according to national laboratories and offsite institutions. Small business innovation research projects are also listed. Special facilities supported wholly or partly by the Division of Chemical Sciences are described. Indexes are provided for selected topics of general interest, institutions, and investigators.

  9. Research proceedings on amphibian model organisms

    PubMed Central

    LIU, Lu-Sha; ZHAO, Lan-Ying; WANG, Shou-Hong; JIANG, Jian-Ping

    2016-01-01

    Model organisms have long been important in biology and medicine due to their specific characteristics. Amphibians, especially Xenopus, play key roles in answering fundamental questions on developmental biology, regeneration, genetics, and toxicology due to their large and abundant eggs, as well as their versatile embryos, which can be readily manipulated and developed in vivo. Furthermore, amphibians have also proven to be of considerable benefit in human disease research due to their conserved cellular developmental and genomic organization. This review gives a brief introduction on the progress and limitations of these animal models in biology and human disease research, and discusses the potential and challenge of Microhyla fissipes as a new model organism. PMID:27469255

  10. Aqueous photolysis of the organic ultraviolet filter chemical octyl methoxycinnamate.

    PubMed

    MacManus-Spencer, Laura A; Tse, Monica L; Klein, Jacob L; Kracunas, Alison E

    2011-05-01

    Organic UV filter chemicals are the active ingredients in personal care products designed to protect the skin from UV radiation, and hundreds of tons are estimated to be produced annually. Despite their entrance into the aquatic environment by both direct and indirect routes and their detection in surface waters and fish, little is known about their environmental fate. UV filter chemicals are designed to be photostable, but some undergo transformation upon exposure to UV light. Octyl methoxycinnamate (OMC), a commonly used UV filter chemical, degrades rapidly by direct photolysis; previous studies have focused on its photoisomerization, and a few investigators have reported the formation of cyclodimers. Here, we present the kinetics and quantum efficiency of the direct photolysis of OMC and confirm that dimerization occurs as a result of direct photolysis in aqueous solution. Likely identities of the dimers are offered based on comparison to reported results for other cinnamate derivatives. We have identified additional products of direct photolysis that have not been previously reported and investigated their photostability, as well as the mechanism of product formation. There is also some evidence of indirect photolysis in the presence of dissolved natural organic matter.

  11. Hazardous organic chemicals in rubber recycled tire playgrounds and pavers.

    PubMed

    Llompart, Maria; Sanchez-Prado, Lucia; Pablo Lamas, J; Garcia-Jares, Carmen; Roca, Enrique; Dagnac, Thierry

    2013-01-01

    In this study, the presence of hazardous organic chemicals in surfaces containing recycled rubber tires is investigated. Direct material analyses using solvent extraction, as well as SPME analysis of the vapour phase above the sample, were carried out. Twenty-one rubber mulch samples were collected from nine different playgrounds. In addition, seven commercial samples of recycled rubber pavers were acquired in a local store of a multinational company. All samples were extracted by ultrasound energy, followed by analysis of the extract by GC-MS. The analysis confirmed the presence of a large number of hazardous substances including PAHs, phthalates, antioxidants (e.g. BHT, phenols), benzothiazole and derivatives, among other chemicals. The study evidences the high content of toxic chemicals in these recycled materials. The concentration of PAHs in the commercial pavers was extremely high, reaching values up to 1%. In addition, SPME studies of the vapour phase above the samples confirm the volatilisation of many of those organic compounds. Uses of recycled rubber tires, especially those targeting play areas and other facilities for children, should be a matter of regulatory concern.

  12. Hydrophobic interaction of organic chemicals with microtubule assembly in vitro.

    PubMed

    Stoiber, Thomas; Unger, Eberhard; Dorn, Susanne B; Degen, Gisela H; Bolt, Hermann M

    2008-09-01

    A recent concept connecting the lipophilicity of organic chemicals with their genotoxicity on a chromosomal level implies that the lipophilic character of organic chemicals determines a certain background of chromosomal genotoxicity that can be addressed as "non-specific". This is opposed to compounds with more "specific" modes of action. Such mechanisms influence the processes of karyokinesis and cytokinesis. A critical partial process for the chromosomal segregation is the dynamics of assembly and disassembly of microtubules. To broaden the present database for such interactions, chemicals were selected based on their lipophilicity (log P between -1.5 and +1.0) and on hints from the literature pointing to possibilities of interaction with the tubulin-microtubule system. Thus, acetamide, acrylamide, methylmethane sulfonate, acetonitrile, acrylonitrile and cyclohexanone were assessed as to their potencies to influence the dynamic processes of microtubule assembly and disassembly in a cell-free system in vitro. These compounds covered a range of log P between -1.5 and 1.0, complementary to compounds investigated earlier. The entire body of data supports the general concept that hydrophobic interactions are connected with non-specific processes, which contribute to a background genotoxicity on a chromosomal level. It also points to the dynamics of microtubule assembly and disassembly as a decisive partial process involved.

  13. AN OVERVIEW OF PATHOGEN RESEARCH IN THE MICROBIOLOGICAL AND CHEMICAL EXPOSURE ASSESSMENT RESEARCH DIVISION

    EPA Science Inventory

    The Microbiological and Chemical Exposure Assessment Research Division of the EPA Office of Research and Development's National Exposure Research Laboratory has a robust in-house research program aimed at developing better occurrence and exposure methods for waterborne pathogens....

  14. Trophic magnification of organic chemicals: A global synthesis

    USGS Publications Warehouse

    Walters, David; Jardine, T.D.; Cade, Brian S.; Kidd, K.A.; Muir, D.C.G.; Leipzig-Scott, Peter C.

    2016-01-01

    Production of organic chemicals (OCs) is increasing exponentially, and some OCs biomagnify through food webs to potentially toxic levels. Biomagnification under field conditions is best described by trophic magnification factors (TMFs; per trophic level change in log-concentration of a chemical) which have been measured for more than two decades. Syntheses of TMF behavior relative to chemical traits and ecosystem properties are lacking. We analyzed >1500 TMFs to identify OCs predisposed to biomagnify and to assess ecosystem vulnerability. The highest TMFs were for OCs that are slowly metabolized by animals (metabolic rate kM < 0.01 day–1) and are moderately hydrophobic (log KOW 6–8). TMFs were more variable in marine than freshwaters, unrelated to latitude, and highest in food webs containing endotherms. We modeled the probability that any OC would biomagnify as a combined function of KOW and kM. Probability is greatest (∼100%) for slowly metabolized compounds, regardless of KOW, and lowest for chemicals with rapid transformation rates (kM > 0.2 day–1). This probabilistic model provides a new global tool for screening existing and new OCs for their biomagnification potential.

  15. Comparison of rapid screening assays using organic chemicals

    SciTech Connect

    Beach, S.A.; Robideau, R.R.

    1994-12-31

    In a continuation of a study presented last year using metals, the sensitivity of short term toxicity tests is examined using common organic chemicals. In toxicity testing, the focus has shifted from the traditional long-term studies utilizing the mortality of complex, multicellular eukaryotic organisms as the endpoint towards short-term studies in which transformation of biochemical pathways are monitored. The relative sensitivity of aquatic screening techniques are compared to the standardized 48-hr Daphnia magna and Ceriodaphnia dubia, 96-hr fathead minnow and 96-hr algal acute assays. The short-term test procedures investigated are: dehydrogenase enzyme activity assays utilizing triphenyltetrazolium chloride (TTC) and resazurin as the calorimetric indicators; TOXI-Chromotest, inhibition of {beta}-galactosidase; reduction in bioluminescence output utilizing the Microtox{reg_sign} test; nitrification inhibition assays with a commercial preparation of nitrifying bacteria (Nitroseed{trademark}) and municipal activated sludge; respiration inhibition assays with a commercial preparation of heterotrophic bacteria (Polytox{reg_sign}) and activated sludge; inhibition of root growth in terrestrial plants; and galactosidase inhibition through the use of a fluorometrically tagged substrate with the Daphnia magna IQ{trademark} test. Toxicity values generated by this laboratory on commonly used organic chemicals are compared.

  16. Measurement of volatile organic chemicals at selected sites in California

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Salas, L.; Viezee, W.; Sitton, B.; Ferek, R.

    1992-01-01

    Urban air concentrations of 24 selected volatile organic chemicals that may be potentially hazardous to human health and environment were measured during field experiments conducted at two California locations, at Houston, and at Denver. Chemicals measured included chlorofluorocarbons, halomethanes, haloethanes, halopropanes, chloroethylenes, and aromatic hydrocarbons. With emphasis on California sites, data from these studies are analyzed and interpreted with respect to variabilities in ambient air concentrations, diurnal changes, relation to prevailing meteorology, sources and trends. Except in a few instances, mean concentrations are typically between 0 and 5 ppb. Significant variabilities in atmospheric concentrations associated with intense sources and adverse meteorological conditions are shown to exist. In addition to short-term variability, there is evidence of systematic diurnal and seasonal trends. In some instances it is possible to detect declining trends resulting from the effectiveness of control strategies.

  17. Chemical ions affect survival of avian cholera organisms in pondwater

    USGS Publications Warehouse

    Price, J.I.; Yandell, B.S.; Porter, W.P.

    1992-01-01

    Avian cholera (Pasteurella multocida) is a major disease of wild waterfowl, but its epizootiology remains little understood. Consequently, we examined whether chemical ions affected survival of avian cholera organisms in water collected from the Nebraska Rainwater Basin where avian cholera is enzootic. We tested the response of P. multocida to ammonium (NH4), calcium (Ca), magnesium (Mg), nitrate (NO3), and ortho-phosphate (PO4) ions individually and in combination using a fractional factorial design divided into 4 blocks. High concentrations of Ca and Mg, singly or in combination, increased survival of P. multocida organisms (P < 0.001). We developed a survival index to predict whether or not specific ponds could be "problem" or "nonproblem" avian cholera sites based on concentrations of these ions in the water.

  18. Chemically Delaminated Free-Standing Ultrathin Covalent Organic Nanosheets.

    PubMed

    Khayum, M Abdul; Kandambeth, Sharath; Mitra, Shouvik; Nair, Sanoop B; Das, Anuja; Nagane, Samadhan S; Mukherjee, Rabibrata; Banerjee, Rahul

    2016-12-12

    Covalent organic nanosheets (CONs) are a new class of porous thin two-dimensional (2D) nanostructures that can be easily designed and functionalized and could be useful for separation applications. Poor dispersion, layer restacking, and difficult postsynthetic modifications are the major hurdles that need to be overcome to fabricate scalable CON thin films. Herein, we present a unique approach for the chemical exfoliation of an anthracene-based covalent organic framework (COF) to N-hexylmaleimide-functionalized CONs, to yield centimeter-sized free-standing thin films through layer-by-layer CON assembly at the air-water interface. The thin-layer fabrication technique presented here is simple, scalable, and does not require any surfactants or stabilizing agents.

  19. Chemical composition of dissolved organic matter draining permafrost soils

    NASA Astrophysics Data System (ADS)

    Ward, Collin P.; Cory, Rose M.

    2015-10-01

    Northern circumpolar permafrost soils contain roughly twice the amount of carbon stored in the atmosphere today, but the majority of this soil organic carbon is perennially frozen. Climate warming in the arctic is thawing permafrost soils and mobilizing previously frozen dissolved organic matter (DOM) from deeper soil layers to nearby surface waters. Previous studies have reported that ancient DOM draining deeper layers of permafrost soils was more susceptible to degradation by aquatic bacteria compared to modern DOM draining the shallow active layer of permafrost soils, and have suggested that DOM chemical composition may be an important control for the lability of DOM to bacterial degradation. However, the compositional features that distinguish DOM drained from different depths in permafrost soils are poorly characterized. Thus, the objective of this study was to characterize the chemical composition of DOM drained from different depths in permafrost soils, and relate these compositional differences to its susceptibility to biological degradation. DOM was leached from the shallow organic mat and the deeper permafrost layer of soils within the Imnavait Creek watershed on the North Slope of Alaska. DOM draining both soil layers was characterized in triplicate by coupling ultra-high resolution mass spectrometry, 13C solid-state NMR, and optical spectroscopy methods with multi-variate statistical analyses. Reproducibility of replicate mass spectra was high, and compositional differences resulting from interfering species or isolation effects were significantly smaller than differences between DOM drained from each soil layer. All analyses indicated that DOM leached from the shallower organic mat contained higher molecular weight, more oxidized, and more unsaturated aromatic species compared to DOM leached from the deeper permafrost layer. Bacterial production rates and bacterial efficiencies were significantly higher for permafrost compared to organic mat DOM

  20. A New Investigative Sophomore Organic Laboratory Involving Individual Research Projects

    NASA Astrophysics Data System (ADS)

    Kharas, Gregory B.

    1997-07-01

    The problem-solving approach calls for a laboratory curriculum that provides a greater intellectual challenge and the resemblance to a research experience. A curriculum was designed which involves individual research projects for the nine laboratories of the spring quarter of a three-quarter introductory organic chemistry course. These projects integrate the instructor's research and learning experiences for the students via interdisciplinary approaches of classical organic chemistry and polymer chemistry. The foundations for the individual research projects are laid out during the first and second quarters of laboratory instruction when students are introduced to classic synthetic, separation and purification techniques. In the third quarter of lab sequence, in carrying out the individual research projects, the emphasis is shifted towards obtaining and interpreting data for compounds that are not described in the laboratory manual rather than making representative compounds. The research is an open end laboratory project that includes an on-line and printed Chemical Abstracts literature search, molecular computer modeling, a microscale monomer synthesis and characterization, scale-up synthesis, polymer synthesis and characterization. By changing functional groups on the vinyl monomer molecule, the class can explore reactivity of one "family" of compounds and consequently polymers. This approach is based on the integration of genuine research experience with laboratory instruction in accessible but non-trivial manner.

  1. Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene.

    PubMed

    Harberts, Megan; Lu, Yu; Yu, Howard; Epstein, Arthur J; Johnston-Halperin, Ezekiel

    2015-07-03

    Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in traditional materials, including low cost and mechanical flexibility. In a similar vein, it would be advantageous to expand the use of organics into high frequency electronics and spin-based electronics. This work presents a synthetic process for the growth of thin films of the room temperature organic ferrimagnet, vanadium tetracyanoethylene (V[TCNE]x, x~2) by low temperature chemical vapor deposition (CVD). The thin film is grown at <60 °C, and can accommodate a wide variety of substrates including, but not limited to, silicon, glass, Teflon and flexible substrates. The conformal deposition is conducive to pre-patterned and three-dimensional structures as well. Additionally this technique can yield films with thicknesses ranging from 30 nm to several microns. Recent progress in optimization of film growth creates a film whose qualities, such as higher Curie temperature (600 K), improved magnetic homogeneity, and narrow ferromagnetic resonance line-width (1.5 G) show promise for a variety of applications in spintronics and microwave electronics.

  2. Modeling regional secondary organic aerosol using the Master Chemical Mechanism

    NASA Astrophysics Data System (ADS)

    Li, Jingyi; Cleveland, Meredith; Ziemba, Luke D.; Griffin, Robert J.; Barsanti, Kelley C.; Pankow, James F.; Ying, Qi

    2015-02-01

    A modified near-explicit Master Chemical Mechanism (MCM, version 3.2) with 5727 species and 16,930 reactions and an equilibrium partitioning module was incorporated into the Community Air Quality Model (CMAQ) to predict the regional concentrations of secondary organic aerosol (SOA) from volatile organic compounds (VOCs) in the eastern United States (US). In addition to the semi-volatile SOA from equilibrium partitioning, reactive surface uptake processes were used to simulate SOA formation due to isoprene epoxydiol, glyoxal and methylglyoxal. The CMAQ-MCM-SOA model was applied to simulate SOA formation during a two-week episode from August 28 to September 7, 2006. The southeastern US has the highest SOA, with a maximum episode-averaged concentration of ∼12 μg m-3. Primary organic aerosol (POA) and SOA concentrations predicted by CMAQ-MCM-SOA agree well with AMS-derived hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA) urban concentrations at the Moody Tower at the University of Houston. Predicted molecular properties of SOA (O/C, H/C, N/C and OM/OC ratios) at the site are similar to those reported in other urban areas, and O/C values agree with measured O/C at the same site. Isoprene epoxydiol is predicted to be the largest contributor to total SOA concentration in the southeast US, followed by methylglyoxal and glyoxal. The semi-volatile SOA components are dominated by products from β-caryophyllene oxidation, but the major species and their concentrations are sensitive to errors in saturation vapor pressure estimation. A uniform decrease of saturation vapor pressure by a factor of 100 for all condensable compounds can lead to a 150% increase in total SOA. A sensitivity simulation with UNIFAC-calculated activity coefficients (ignoring phase separation and water molecule partitioning into the organic phase) led to a 10% change in the predicted semi-volatile SOA concentrations.

  3. Mechanical-chemical coupling and self-organization in mudstones.

    SciTech Connect

    Heath, Jason E.; Dewers, Thomas A.

    2010-06-01

    Shales and other mudstones are the most abundant rock types in sedimentary basins, yet have received comparatively little attention. Common as hydrocarbon seals, these are increasingly being targeted as unconventional gas reservoirs, caprocks for CO{sub 2} sequestration, and storage repositories for waste. The small pore and grain size, large specific surface areas, and clay mineral structures lend themselves to rapid reaction rates accompanying changes in stress, pressure, temperature and chemical conditions. Under far from equilibrium conditions, mudrocks display a variety of spatio-temporal self-organized phenomena arising from the nonlinear coupling of mechanics with chemistry. Beginning with a detailed examination of nano-scale pore network structures in mudstones, we discuss the dynamics behind such self-organized phenomena as pressure solitons, chemically-induced flow self focusing and permeability transients, localized compaction, time dependent well-bore failure, and oscillatory osmotic fluxes as they occur in clay-bearing sediments. Examples are draw from experiments, numerical simulation, and the field. These phenomena bear on the ability of these rocks to serve as containment barriers.

  4. 40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of... Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory. The provisions of this subpart...

  5. 15 CFR Supplement No. 1 to Part 715 - Definition of an Unscheduled Discrete Organic Chemical

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Organic Chemical No. Supplement No. 1 to Part 715 Commerce and Foreign Trade Regulations Relating to... WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 1 Supplement No. 1 to Part 715—Definition of an Unscheduled Discrete Organic Chemical...

  6. 15 CFR Supplement No. 1 to Part 715 - Definition of an Unscheduled Discrete Organic Chemical

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Organic Chemical No. Supplement No. 1 to Part 715 Commerce and Foreign Trade Regulations Relating to... WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 1 Supplement No. 1 to Part 715—Definition of an Unscheduled Discrete Organic Chemical...

  7. 78 FR 37222 - Columbia Organic Chemical Company Site, Columbia, Richland County, South Carolina; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... AGENCY Columbia Organic Chemical Company Site, Columbia, Richland County, South Carolina; Notice of... Columbia Organic Chemical Company Superfund Site located in Columbia, Richland County, South Carolina. The.... Submit your comments by site name Columbia Organic Chemical Company by one of the following methods:...

  8. 15 CFR Supplement No. 1 to Part 715 - Definition of an Unscheduled Discrete Organic Chemical

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Organic Chemical No. Supplement No. 1 to Part 715 Commerce and Foreign Trade Regulations Relating to... WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 1 Supplement No. 1 to Part 715—Definition of an Unscheduled Discrete Organic Chemical...

  9. 40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of... Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory. The provisions of this subpart...

  10. 15 CFR Supplement No. 1 to Part 715 - Definition of an Unscheduled Discrete Organic Chemical

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Organic Chemical No. Supplement No. 1 to Part 715 Commerce and Foreign Trade Regulations Relating to... WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 1 Supplement No. 1 to Part 715—Definition of an Unscheduled Discrete Organic Chemical...

  11. 15 CFR Supplement No. 1 to Part 715 - Definition of an Unscheduled Discrete Organic Chemical

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Organic Chemical No. Supplement No. 1 to Part 715 Commerce and Foreign Trade Regulations Relating to... WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 1 Supplement No. 1 to Part 715—Definition of an Unscheduled Discrete Organic Chemical...

  12. The chemical ecology of soil organic matter molecular constituents.

    PubMed

    Simpson, Myrna J; Simpson, André J

    2012-06-01

    Soil organic matter (OM) contains vast stores of carbon, and directly supports microbial, plant, and animal life by retaining essential nutrients and water in the soil. Soil OM plays important roles in biological, chemical, and physical processes within the soil, and arguably plays a major role in maintaining long-term ecological stability in a changing world. Despite its importance, there is a great deal still unknown about soil OM chemical ecology. The development of sophisticated analytical methods have reshaped our understanding of soil OM composition, which is now believed to be comprised of plant and microbial products at various stages of decomposition. The methods also have recently been applied to study environmental change in various settings and have provided unique insight with respect to soil OM chemical ecology. The goal of this review is to highlight the methods used to characterize soil OM structure, source, and degradation that have enabled precise observations of OM and associated ecological shifts. Although the chemistry of soil OM is important in its overall fate in ecosystems, the studies conducted to date suggest that ecological function is not defined by soil OM chemistry alone. The long-standing questions regarding soil OM stability and recalcitrance will likely be answered when several molecular methods are used in tandem to closely examine structure, source, age, degradation stage, and interactions of specific OM components in soil.

  13. Wildlife ecological screening levels for inhalation of volatile organic chemicals.

    PubMed

    Gallegos, Patricia; Lutz, Jill; Markwiese, James; Ryti, Randall; Mirenda, Rich

    2007-06-01

    For most chemicals, evaluation of ecological risk typically does not address inhalation because ingestion dominates exposure. However, burrowing ecological receptors have an increased exposure potential from inhalation at sites contaminated with volatile chemicals in the subsurface. Evaluation of ecological risk from contaminants like volatile organic chemicals (VOCs) is constrained by a lack of relevant ecological screening levels (ESLs). To address this need, inhalation ESLs were developed for 16 VOCs: Acetone, benzene, carbon tetrachloride, chloroform, chloromethane, dichlorodifluoromethane, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloroethene, methylene chloride, tetrachloroethene, toluene, 1,1,1-trichloroethane, trichloroethene, trichlorofluoromethane, and total xylene. These ESLs are based on Botta's pocket gopher (Thomomys bottae) as a representative fossorial receptor. The ESLs are presented with an emphasis on the process for developing inhalation toxicity reference values to illustrate the selection of suitable toxicity data and effect levels from the literature. The resulting ESLs provide a quantitative method for evaluating ecological risk of VOCs through comparison to relevant exposure data such as direct burrow-air measurements. The toxicity reference value development and ESL calculation processes and assumptions detailed here are provided as bases from which risk assessors can use or refine to suit site-specific needs with respect to toxicity and exposure inputs.

  14. Chemical and Spatial Microscopy of Individual Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Tivanski, Alexei V.; Hopkins, Rebecca J.; Gilles, Mary K.

    2008-03-01

    Carbonaceous particles originating from biomass burning can account for a large fraction of organic aerosols in a local environment. Presently, their composition, physical, and chemical properties as well as their environmental effects are largely unknown. A distinct type of biomass burn particles, called ``tar balls'', have been observed in a number of field campaigns, both in fresh and aged smoke. They are characterized by their spherical morphology, high carbon content and ability to efficiently scatter and absorb light. Here, a combination of scanning transmission x-ray microscopy and near edge x-ray absorption fine structure spectroscopy is used to determine the shape, structure and size-dependent chemical composition of 150 individual tar ball particles ranging in size from 0.15 to 1.2 μm. Oxygen is present primarily as carboxylic carbonyls and oxygen-substituted alkyl functional groups. The observed chemical composition is distinctly different from black carbon and more closely resembles high molecular weight humic-like substances. A detailed examination of the carbonyl intensity as a function of particle size reveals the presence of a thin oxygenated interface layer on the tar balls, indicative of atmospheric processing of biomass burn particles.

  15. Bibliography of Short Wavelength Chemical Laser Research

    DTIC Science & Technology

    1993-05-01

    shock tube dissociation of fluorine azide, (2) identify and characterize alternatives to BiF as the lasant in an excited NF driven laser , (3) develop...L.F. Phillips KINETICS OF 12 FOLLOWING ArF LASER EXCITATION: THERMAL DISSOCIATION OF THE A’(2u) STATE J. Phys. Chem., 88, 6084 (1984) 267. Tellinghuisen...VISIBLE WAVELENGTH CHEMICAL LASER SCHEMES BASED ON THERMAL DISSOCIATION OF CHLORINE AZIDE Proc. Int. Conf on.LASERS 󈨟, Eds. F.J. Duarte and D.G. Harris

  16. Toxic Industrial Chemical Removal by Isostructural Metal-Organic Frameworks

    DTIC Science & Technology

    2011-01-01

    ISOSTRUCTURAL METAL-ORGANIC FRAMEWORKS Gregory W. Peterson RESEARCH AND TECHNOLOGY DIRECTORATE T. Grant Glover Bryan J. Schindler SCIENCE...APPLICATIONS INTERNATIONAL CORPORATION Gunpowder, MD 21010-0068 David Britt Omar Yaghi UNIVERSITY OF CALIFORNIA Los Angeles, CA 90095-1569 January 2011...Frameworks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Peterson, Gregory W. (ECBC); Glover, T. Grant; Schindler

  17. Education: Chemical Research Council Gains Solid Financial Footing.

    ERIC Educational Resources Information Center

    Kiefer, David

    1982-01-01

    Conceived three years ago, the Council for Chemical Research (CCR) is meeting its goal to expedite technological transfer between universities and industry. Although funding is still a problem, membership is growing (37 industries and 128 universities). CCR encourages industrial grants to chemistry/chemical engineering departments and the Chemical…

  18. Research and Development and the Chemical Industry: Implications for Education.

    ERIC Educational Resources Information Center

    Aschbacher, Pam

    This paper describes the research and development (R & D) strategy employed in a major chemical manufacturing corporation and compares the strategy to that which is generally used in educational R & D efforts. The paper underscores development practices in the chemical industry as they relate to devleopment activities in education. Some of the…

  19. Chemical research at Argonne National Laboratory

    SciTech Connect

    1997-04-01

    Argonne National Laboratory is a research and development laboratory located 25 miles southwest of Chicago, Illinois. It has more than 200 programs in basic and applied sciences and an Industrial Technology Development Center to help move its technologies to the industrial sector. At Argonne, basic energy research is supported by applied research in diverse areas such as biology and biomedicine, energy conservation, fossil and nuclear fuels, environmental science, and parallel computer architectures. These capabilities translate into technological expertise in energy production and use, advanced materials and manufacturing processes, and waste minimization and environmental remediation, which can be shared with the industrial sector. The Laboratory`s technologies can be applied to help companies design products, substitute materials, devise innovative industrial processes, develop advanced quality control systems and instrumentation, and address environmental concerns. The latest techniques and facilities, including those involving modeling, simulation, and high-performance computing, are available to industry and academia. At Argonne, there are opportunities for industry to carry out cooperative research, license inventions, exchange technical personnel, use unique research facilities, and attend conferences and workshops. Technology transfer is one of the Laboratory`s major missions. High priority is given to strengthening U.S. technological competitiveness through research and development partnerships with industry that capitalize on Argonne`s expertise and facilities. The Laboratory is one of three DOE superconductivity technology centers, focusing on manufacturing technology for high-temperature superconducting wires, motors, bearings, and connecting leads. Argonne National Laboratory is operated by the University of Chicago for the U.S. Department of Energy.

  20. Feasibility Study of the Development of a Specialized Computer System of Organic Chemical Signatures of Spectral Data.

    ERIC Educational Resources Information Center

    Scholtz, R. G.; And Others

    This final report of a feasibility study describes the research performed in assessing the requirements for a chemical signature file and search scheme for organic compound identification and information retrieval. The research performed to determined feasibility of identifying an unknown compound involved screening the compound against a file of…

  1. INTEGRATED LABORATORY AND FIELD CHARACTERIZATION OF ORGANIC CARBON IN PM 2.5 FORMED THROUGH CHEMICAL REACTIONS

    EPA Science Inventory

    An integrated laboratory and field research program is underway at the National Exposure Research Laboratory (NERL) to characterize organic carbon in PM2.5 (particulate matter) formed through chemical reactions. Information from this study will provide critical data ne...

  2. Aqueous organic chemistry in the atmosphere: sources and chemical processing of organic aerosols.

    PubMed

    McNeill, V Faye

    2015-02-03

    Over the past decade, it has become clear that aqueous chemical processes occurring in cloud droplets and wet atmospheric particles are an important source of organic atmospheric particulate matter. Reactions of water-soluble volatile (or semivolatile) organic gases (VOCs or SVOCs) in these aqueous media lead to the formation of highly oxidized organic particulate matter (secondary organic aerosol; SOA) and key tracer species, such as organosulfates. These processes are often driven by a combination of anthropogenic and biogenic emissions, and therefore their accurate representation in models is important for effective air quality management. Despite considerable progress, mechanistic understanding of some key aqueous processes is still lacking, and these pathways are incompletely represented in 3D atmospheric chemistry and air quality models. In this article, the concepts, historical context, and current state of the science of aqueous pathways of SOA formation are discussed.

  3. ENDOCRINE DISRUPTING CHEMICAL RISK MANAGEMENT RESEARCH IN THE US EPA'S OFFICE OF RESEARCH AND DEVELOPMENT

    EPA Science Inventory

    Endocrine disrupting chemicals (EDCs) are receiving increasing media and scientific attention. Concerns about these chemicals stem from the possibility of serious human and wildlife effects and environmental persistence. The US EPA Office of Research and Development's National ...

  4. Genotoxic activity of organic chemicals in drinking water.

    PubMed

    Meier, J R

    1988-11-01

    The information summarized in this review provides substantial evidence for the widespread presence of genotoxins in drinking water. In many, if not most cases, the genotoxic activity can be directly attributed to the chlorination stage of drinking water treatment. The genotoxic activity appears to originate primarily from reactions of chlorine with humic substances in the source waters. Genotoxic activity in drinking water concentrates has been most frequently demonstrated using bacterial mutagenicity tests but results with mammalian cell assay systems are generally consistent with the findings from the bacterial assays. There is currently no evidence for genotoxic damage following in vivo exposures to animals. In some locations genotoxic contaminants of probable industrial and/or agricultural origin occur in the source waters and contribute substantially to the genotoxic activity of finished drinking waters. The method used for sample concentration can have an important bearing on study results. In particular, organic acids account for most of the mutagenicity of chlorinated drinking water, and their recovery from water requires a sample acidification step prior to extraction or XAD resin adsorption. Considerable work has been done to determine the identity of the compounds responsible for the mutagenicity of organic concentrates of drinking water. Recently, one class of acidic compounds, the chlorinated hydroxyfuranones, has been shown to be responsible for a major part of the mutagenic activity. Strategies for drinking water treatment that have been evaluated with respect to reduction of genotoxins in drinking water include granular activated carbon (GAC) filtration, chemical destruction, and the use of alternative means of treatment (i.e., ozone, chlorine dioxide, and monochloramine). GAC treatment has been found to be effective for removal of mutagens from drinking water even after the GAC is beyond its normal use for organic carbon removal. All disinfectant

  5. Summaries of FY 1979 research in the chemical sciences

    SciTech Connect

    Not Available

    1980-05-01

    The purpose of this report is to help those interested in research supported by the Department of Energy's Division of Chemical Sciences, which is one of six Divisions of the Office of Basic Energy Sciences in the Office of Energy Research. Chemists, physicists, chemical engineers and others who are considering the possibility of proposing research for support by this Division wll find the booklet useful for gauging the scope of the program in basic research, and the relationship of their interests to the overall program. These smmaries are intended to provide a rapid means for becoming acquainted with the Chemical Sciences program for members of the scientific and technological public, and interested persons in the Legislative and Executive Branches of the Government, in order to indicate the areas of research supported by the Division and energy technologies which may be advanced by use of basic knowledge discovered in this program. Scientific excellence is a major criterion applied in the selection of research supported by Chemical Sciences. Another important consideration is the identifying of chemical, physical and chemical engineering subdisciplines which are advancing in ways which produce new information related to energy, needed data, or new ideas.

  6. Evaluation of Chemical and Atmospheric Sciences Research

    DTIC Science & Technology

    1984-09-09

    I Geil 48 Benesch 49 Niedenzu B/B+ 1 Marchand 26 El Batouay 9 Tuazon B 24 Maddou 33 Thompson23 Winefordner 21) Lauer 30) Me-’nzer 0’ SalK 7 Lin C 28...APOSR CHEMISTRY RESEARCH- EVALUATION CATE3GORY I CATEGORY TI A+36 Jonas 43 Field A 06 Hubbard 25 Williams 29 Bernstein 24 Smalley 19 Winograd * 14 Rice

  7. Transferring Chemical Research to a Spin-Off Initiative in Health Care: The Lipidomic Approach

    ERIC Educational Resources Information Center

    Ferreri, Carla; Chatgilialoglu, Chryssostomos; Ferreri, Rosaria

    2008-01-01

    Lipidomics is an emerging discipline in life sciences related to the lipid metabolism of living organisms. In the last decade chemical and biological research has attributed very important roles to membrane phospholipids in relationship to free radical stress and metabolic situations. An entrepreneurial initiative for diagnostic tools and health…

  8. The applications of chemical thermodynamics and chemical kinetics to planetary atmospheres research

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.

    1990-01-01

    A review of the applications of chemical thermodynamics and chemical kinetics to planetary atmospheres research during the past four decades is presented with an emphasis on chemical equilibrium models and thermochemical kinetics. Several current problems in planetary atmospheres research such as the origin of the atmospheres of the terrestrial planets, atmosphere-surface interactions on Venus and Mars, deep mixing in the atmospheres of the gas giant planets, and the origin of the atmospheres of outer planet satellites all require laboratory data on the kinetics of thermochemical reactions for their solution.

  9. Utilization of oil shales and basic research in organic geochemistry

    NASA Astrophysics Data System (ADS)

    Burnham, A. K.

    1982-01-01

    Summarized are current research needs relating to oil shale utilization which might also provide new insight into the organic geochemistry of the Green River formation. There are two general topics which cross boundaries and are particularly worthy of emphasis. The first is a study of changes in the kerogen structure and biological markers with depth and location, and how these changes affect the pyrolysis products. This information would be particularly useful to the retort diagnostic methods. It might also lead to a better chemical reaction model of diagenesis and metagenesis. The second is a study of the heteroatom chemistry of the kerogen and how it relates to mineral matter and trace metals. This would be useful not only to present utilization methods, but also might suggest new nonthermal methods of organic material recovery.

  10. pH-Dependent sorption of acidic organic chemicals to soil organic matter.

    PubMed

    Tülp, Holger C; Fenner, Kathrin; Schwarzenbach, René P; Goss, Kai-Uwe

    2009-12-15

    Due to their increased polarity, many contemporary biologically active chemicals exhibit acid functions and may thus dissociate to their anionic conjugated base at pH values typically present in the environment. Despite its negative charge, soil organic matter (SOM) has been demonstrated to be the main sorbent in soils, even for the anionic species of organic acids. Nevertheless, few data exist that allow for a systematic interpretation of the sorption of organic acids into SOM. Therefore, in this study, the sorption of the neutral and anionic species of 32 diverse organic acids belonging to nine different chemical groups to SOM was investigated. Partition coefficients were determined from HPLC retention volumes on a column packed with peat, at three Ca(2+)-concentrations and over a pH range of 4.5-7.5. The influence of Ca(2+)-concentrations on anion sorption was small (factor 2 in the usual environmental Ca(2+)-concentration range) and independent of molecular structure. Generally, the organic carbon-water partition coefficients, K(oc), of both the neutral and anionic species increased with increasing molecular size and decreased with increasing polarity. At an environmentally relevant Ca(2+)-concentration of 10 mM, the investigated anions sorbed between a factor of 7-60 less than the corresponding neutral acid. This factor was more homogeneous within a group of structurally related compounds. These results indicate that while similar nonionic interactions seem to govern the partitioning of both the neutral and anionic species into SOM, the electrostatic interactions of the anionic species with SOM are a complex and currently not well understood function of the type of acidic functional group. The HPLC-based, flow through method presented in this study was shown to yield consistent results for a wide range of organic acids in a high-throughput manner. It should therefore prove highly useful in further investigating how different acidic functional groups affect

  11. 2011 Chemical Reactions at Surfaces Gordon Research Conference

    SciTech Connect

    Peter Stair

    2011-02-11

    The Gordon Research Conference on Chemical Reactions at Surfaces is dedicated to promoting and advancing the fundamental science of interfacial chemistry and physics by providing surface scientists with the foremost venue for presentation and discussion of research occurring at the frontiers of their fields.

  12. Organic chemical degradation by remote study of the redox conditions

    NASA Astrophysics Data System (ADS)

    Fernandez, P. M.; Revil, A.; Binley, A. M.; Bloem, E.; French, H. K.

    2014-12-01

    Monitoring the natural (and enhanced) degradation of organic contaminants is essential for managing groundwater quality in many parts of the world. Contaminated sites often have limited access, hence non-intrusive methods for studying redox processes, which drive the degradation of organic compounds, are required. One example is the degradation of de-icing chemicals (glycols and organic salts) released to the soil near airport runways during winter. This issue has been broadly studied at Oslo airport, Gardermoen, Norway using intrusive and non-intrusive methods. Here, we report on laboratory experiments that aim to study the potential of using a self-potential, DCresistivity, and time-domain induced polarization for geochemical characterization of the degradation of Propylene Glycol (PG). PG is completely miscible in water, does not adsorb to soil particles and does not contribute to the electrical conductivity of the soil water. When the contaminant is in the unsaturated zone near the water table, the oxygen is quickly consumed and the gas exchange with the surface is insufficient to ensure aerobic degradation, which is faster than anaerobic degradation. Since biodegradation of PG is highly oxygen demanding, anaerobic pockets can exist causing iron and manganese reduction. It is hypothesised that nitrate would boost the degradation rate under such conditions. In our experiment, we study PG degradation in a sand tank. We provide the system with an electron highway to bridge zones with different redox potential. This geo-battery system is characterized by self-potential, resistivity and induced polarization anomalies. An example of preliminary results with self-potential at two different times of the experiment can be seen in the illustration. These will be supplemented with more direct information on the redox chemistry: in-situ water sampling, pH, redox potential and electrical conductivity measurements. In parallel, a series of batch experiments have been

  13. Screening chemicals for the potential to be persistent organic pollutants: a case study of Arctic contaminants.

    PubMed

    Brown, Trevor N; Wania, Frank

    2008-07-15

    A large and ever-increasing number of chemicals are used in commerce, and researchers and regulators have struggled to ascertain that these chemicals do not threaten human health or cause environmental or ecological damage. The presence of persistent organic pollutants (POPs) in remote environments such as the Arctic is of special concern and has international regulatory implications. Responding to the need for a way to identify chemicals of high concern, a methodology has been developed which compares experimentally measured properties, or values predicted from chemical structure alone, to a set of screening criteria. These criteria include partitioning properties that allow for accumulation in the physical Arctic environment and in the Arctic human food chain, and resistance to atmospheric oxidation. Atthe same time we quantify the extent of structural resemblance to a group of known Arctic contaminants. Comparison of the substances that are identified by a mechanistic description of the processes that lead to Arctic contamination with those substances that are structurally similar to known Arctic contaminants reveals the strengths and limitations of either approach. Within a data set of more than 100,000 distinct industrial chemicals, the methodology identifies 120 high production volume chemicals which are structurally similarto known Arctic contaminants and/or have partitioning properties that suggest they are potential Arctic contaminants.

  14. Effects of water hardness and dissolved organic material on bioavailability of selected organic chemicals.

    PubMed

    Akkanen, J; Kukkonen, J V

    2001-10-01

    The influence of water hardness and dissolved organic matter (DOM) on bioavailability of organic chemicals to Daphnia magna was studied by using benzo[a]pyrene (BaP), pyrene, atrazine, and 3,3',4,4'-tetrachlorobiphenyl (TCB) as model compounds. Two types of DOM were used, namely Lake Kontiolampi, Joensuu, Finland water (KL) and Nordic reference fulvic acid (NoFA) dissolved in artificial freshwater. Binding of the four contaminants by KL DOM decreased with increasing water hardness. Furthermore, increasing hardness reduced the binding of BaP and pyrene to NoFA. The binding of atrazine and TCB by NoFA was low and was not significantly affected by water hardness. In the DOM-free samples, the bioconcentration of the four contaminants in D. magna usually was not affected by water hardness. In the presence of DOM, the bioconcentration factors (BCFs) were lower (except for atrazine) than in the DOM-free controls. In the presence of both types of DOM, increasing water hardness resulted in higher BCFs for BaP. The bioconcentration of pyrene and TCB increased with increasing water hardness in the presence of KL DOM. In conclusion, the effects of DOM and water hardness on bioavailability of hydrophobic chemicals depend on the type of chemical and on the properties of DOM.

  15. Research briefs of the Physical and Chemical Sciences Center

    SciTech Connect

    Vook, F.L.; Smith, W.L.

    1993-12-31

    As Sandia National Laboratories and the Physical and Chemical Sciences Center develop an increasingly diverse set of customers, research partners, and Cooperative Research and Development Agreements (CRADA`s) with industry, there is a need for providing more concise information describing their technical achievements and capabilities. This publication, Research Briefs, is designed to inform the present and potential partners in research and technology advancement. Their research emphasizes semiconductor physics, electronic materials, surface physics and chemistry, plasma and chemical processing sciences, lasers and optics, vision science, ion-solid interactions and defect physics, and advanced materials physics. The specific programs they pursue are driven by the research goals which are greatly influenced by interactions with the government and industrial customers.

  16. Future research trends in the major chemical language of bacteria.

    PubMed

    Venturi, Vittorio; Subramoni, Sujatha

    2009-01-01

    Microbiology was revolutionized in the 1990's by the discovery that many different bacterial species coordinate their behavior when they form a group. In fact, bacteria are now considered multicellular organisms capable of communicating and changing behavior in relation to their cell-density; since 1994 this has been called quorum sensing. This group behavior ensures survival and propagation of the community in many natural environments. Bacterial intercellular communication is mediated by different chemical signals that are synthesized by bacteria which are then either secreted or diffused in the external environment. Bacteria are then able to detect the type and concentration of the signal resulting in regulation of gene expression and, consequently, a synchronized response by the community. The predominant signalling molecules produced by Gram-negative bacteria are N-acyl derivatives of homoserine lactone (AHLs) which have been shown to be produced by over seventy bacterial species. In this essay we discuss the importance of quorum sensing via AHLs and highlight current and future trends in this important field of research.

  17. Future research trends in the major chemical language of bacteria

    PubMed Central

    Venturi, Vittorio; Subramoni, Sujatha

    2009-01-01

    Microbiology was revolutionized in the 1990’s by the discovery that many different bacterial species coordinate their behavior when they form a group. In fact, bacteria are now considered multicellular organisms capable of communicating and changing behavior in relation to their cell-density; since 1994 this has been called quorum sensing. This group behavior ensures survival and propagation of the community in many natural environments. Bacterial intercellular communication is mediated by different chemical signals that are synthesized by bacteria which are then either secreted or diffused in the external environment. Bacteria are then able to detect the type and concentration of the signal resulting in regulation of gene expression and, consequently, a synchronized response by the community. The predominant signalling molecules produced by Gram-negative bacteria are N-acyl derivatives of homoserine lactone (AHLs) which have been shown to be produced by over seventy bacterial species. In this essay we discuss the importance of quorum sensing via AHLs and highlight current and future trends in this important field of research. PMID:19794815

  18. Research Progress on Chemical Constituents of Lonicerae japonicae flos

    PubMed Central

    Wang, Lingna; Jiang, Qiu; Hu, Jinghong; Zhang, Yongqing; Li, Jia

    2016-01-01

    Lonicerae japonicae flos is commonly used in traditional Chinese medicine for thousands of years with confirmed curative effects. Except for medicine, it is also used in healthy food, cosmetics, and soft beverages for its specific activities. Therefore, the chemical constituents, mainly including organic acids, flavonoids, iridoids, triterpenoids, and volatile oils, have been well studied by many scholars in recent years and a comprehensive and systematic review on chemical constituents of Lonicerae japonicae flos is indispensable. This paper aims at reviewing the chemical components of LJF in recent years through searching for the literatures both at home and abroad. Our results show that 212 components have been isolated from Lonicerae japonicae flos, including 27 flavonoids, 40 organic acids, 83 iridoids, 17 triterpenoids, and 45 other compounds, which could lay a foundation for the further application of Lonicerae japonicae flos. PMID:27403439

  19. The energetic and chemical fingerprints of persistent soil organic carbon

    NASA Astrophysics Data System (ADS)

    Barré, Pierre; Plante, Alain F.; Cécillon, Lauric; Lutfalla, Suzanne; Baudin, François; Bernard, Sylvain; Christensen, Bent T.; Fernandez, Jose M.; Houot, Sabine; Kätterer, Thomas; Macdonald, Andy; van Oort, Folkert; Le Guillou, Corentin; Chenu, Claire

    2016-04-01

    A better understanding of soil organic carbon (SOC) persistence is needed to better predict SOC vulnerability to global change. The absence of convincing physical or chemical procedures to define, characterize or isolate relatively labile versus persistent SOC pools makes the study of persistent SOC difficult. Long-term bare fallow (LTBF) experiments, in which C inputs have been stopped for several decades, provide a unique opportunity to study persistent SOC without the inherent artefacts induced by extraction procedures, the hypothesis being that SOC is gradually enriched in persistent C with time as labile components decompose. We determined the evolution of thermal and chemical characteristics of bulk SOC in five LTBF experiments across Europe: Askov (DK), Grignon (FR), Rothamsted (UK), Ultuna (SW) and Versailles (FR), using a multi-technique approach involving Rock-Eval pyrolysis, thermogravimetry and differential scanning calorimetry (TG-DSC), mid-infrared diffuse reflectance spectroscopy (DRIFT-MIRS), and Near Edge X-Ray Absorption Fine Structure (NEXAFS). Results of Rock-Eval and TG analyses showed that the temperature needed to combust the SOC increased with bare fallow duration at all sites. Conversely, SOC energy density (in mJ mg-1 C) measured by DSC decreased with bare fallow duration. Rock-Eval pyrolysis results showed that hydrogen index (HI) tended to decrease with bare fallow duration whereas the oxygen index (OI) did not show consistent trends across sites. NEXAFS signals presented little differences and were dominated by carboxyl peak. Nonetheless, NEXAFS results showed a trend of increasing carboxyl groups and decreasing ketone and amide groups with bare fallow duration. Due to the mineral matrix, only a reduced part of the DRIFT-MIRS signals has been used. We observed that the bulk chemistry of aliphatic SOC (CH3 vs. CH2 functional groups) showed different trends for the different sites. Our results showed that in spite of the heterogeneity of

  20. Sorption capacity of plastic debris for hydrophobic organic chemicals.

    PubMed

    Lee, Hwang; Shim, Won Joon; Kwon, Jung-Hwan

    2014-02-01

    The occurrence of microplastics (MPs) in the ocean is an emerging world-wide concern. Due to high sorption capacity of plastics for hydrophobic organic chemicals (HOCs), sorption may play an important role in the transport processes of HOCs. However, sorption capacity of various plastic materials is rarely documented except in the case of those used for environmental sampling purposes. In this study, we measured partition coefficients between MPs and seawater (KMPsw) for 8 polycyclic aromatic hydrocarbons (PAHs), 4 hexachlorocyclohexanes (HCHs) and 2 chlorinated benzenes (CBs). Three surrogate polymers - polyethylene, polypropylene, and polystyrene - were used as model plastic debris because they are the major components of microplastic debris found. Due to the limited solubility of HOCs in seawater and their long equilibration time, a third-phase partitioning method was used for the determination of KMPsw. First, partition coefficients between polydimethylsiloxane (PDMS) and seawater (KPDMSsw) were measured. For the determination of KMPsw, the distribution of HOCs between PDMS or plastics and solvent mixture (methanol:water=8:2 (v/v)) was determined after apparent equilibrium up to 12 weeks. Plastic debris was prepared in a laboratory by physical crushing; the median longest dimension was 320-440 μm. Partition coefficients between polyethylene and seawater obtained using the third-phase equilibrium method agreed well with experimental partition coefficients between low-density polyethylene and water in the literature. The values of KMPsw were generally in the order of polystyrene, polyethylene, and polypropylene for most of the chemicals tested. The ranges of log KMPsw were 2.04-7.87, 2.18-7.00, and 2.63-7.52 for polyethylene, polypropylene, and polystyrene, respectively. The partition coefficients of plastic debris can be as high as other frequently used partition coefficients, such as 1-octanol-water partition coefficients (Kow) and log KMPsw showed good linear

  1. Disposition of xenobiotic chemicals and metabolites in marine organisms

    SciTech Connect

    Varanasi, U.; Stein, J.E. )

    1991-01-01

    Studies with several bottom fish species from urban waterways show that of the identified xenobiotic chemicals in bottom sediments, polycyclic aromatic hydrocarbons (PAHs) are the most strongly associated with the prevalence of liver lesions, including neoplasms. Accordingly, there is concern about the transfer of contaminants, such as PAHs, from aquatic species to humans. Because PAHs exert their toxicity only after being biotransformed, increasing attention has been focused on the ability of aquatic organisms to metabolize these chemicals. Overall, the results of both laboratory and field studies show that generally low levels of a few low molecular weight PAHs may be present in edible tissue of fish from contaminated areas and that high molecular weight PAHs, such as the carcinogen benzo(a)pyrene, will rarely be detected because of extensive metabolism. Additionally, the results from a few studies suggest that even though interactions between xenobiotics can affect both biochemical and physiological systems to alter the disposition of PAHs in fish, these interactions do not markedly change the relative proportions of metabolites to parent PAH in tissues. Thus, these studies clearly demonstrate that to obtain some insight into the questions of whether there is any risk to human health from consuming fish and crustaceans from urban areas, techniques must be developed that measure metabolites of carcinogens, such as PAHs, in edible tissue. Initial attempts may focus on semiquantitative methods that permit rapid assessment of the level of metabolites in edible tissues of fish and crustaceans from many urban areas. Based on information from such screening studies, further refinement in methodology leading to identification of specific compounds may be needed because certain metabolites may not be as toxic or carcinogenic as others.

  2. Disposition of xenobiotic chemicals and metabolites in marine organisms.

    PubMed Central

    Varanasi, U; Stein, J E

    1991-01-01

    Studies with several bottom fish species from urban waterways show that of the identified xenobiotic chemicals in bottom sediments, polycylic aromatic hydrocarbons (PAHs) are the most strongly associated with the prevalence of liver lesions, including neoplasms. Accordingly, there is concern about the transfer of contaminants, such as PAHs, from aquatic species to humans. Because PAHs exert their toxicity only after being biotransformed, increasing attention has been focused on the ability of aquatic organisms to metabolize these chemicals. Overall, the results of both laboratory and field studies show that generally low levels (nanograms per gram wet weight) of a few low molecular weight PAHs may be present in edible tissue of fish from contaminated areas and that high molecular weight PAHs, such as the carcinogen benzo(a)pyrene, will rarely be detected because of extensive metabolism. Additionally, the results from a few studies suggest that even though interactions between xenobiotics can affect both biochemical and physiological systems to alter the disposition of PAHs in fish, these interactions do not markedly change the relative proportions of metabolites to parent PAH in tissues. Thus, these studies clearly demonstrate that to obtain some insight into the questions of whether there is any risk to human health from consuming fish and crustaceans from urban areas, techniques must be developed that measure metabolites of carcinogens, such as PAHs, in edible tissue. Initial attempts may focus on semiquantitative methods that permit rapid assessment of the level of metabolites in edible tissues of fish and crustaceans from many urban areas.(ABSTRACT TRUNCATED AT 250 WORDS) Images FIGURE 4. FIGURE 4. FIGURE 4. PMID:2050086

  3. Short-term effects of different organic amendments on soil chemical, biochemical and biological indicators

    NASA Astrophysics Data System (ADS)

    Mondelli, Donato; Aly, Adel; Yirga Dagnachew, Ababu; Piscitelli, Lea; Dumontet, Stefano; Miano, Teodoro

    2014-05-01

    The limited availability of animal manure and the high cost of good quality compost lead to difficult soil quality management under organic agriculture. Therefore, it is important to find out alternative organic soil amendments and more flexible strategies that are able to sustain crop productivity and maintain and enhance soil quality. A three years study was carried out in the experimental fields of the Mediterranean Agronomic Institute of Bari located in Valenzano, Italy. The main objective of this research is to investigate the effects of different fertility management strategies on soil quality in order to estimate the role of innovative matrices for their use in organic farming. The experiment consists of seven treatments applied to a common crop rotation. The treatments include alternative organic amendments (1- olive mill wastewater OMW, 2- residues of mushroom cultivation MUS, 3- coffee chaff COF), common soil amendments (4- compost COM, 5- faba bean intercropping LEG, 6- cow manure - MAN) and as a reference treatment (7- mineral fertilizer COV). The soil quality was assessed before and after the application of the treatments, through biological (microbial biomass carbon and nitrogen, soil respiration and metabolic quotient), biochemical (soil enzymatic activities: β-glucosidase, alkaline phospatase, urease, fluorescein diacetate (FDA) hydrolysis), and chemical (pH, soil organic carbon, soil organic matter, total nitrogen, available phosphorous, exchangeable potassium, dissolved organic carbon and total dissolved nitrogen) indicators. Based on the results obtained after the second year, all treatments were able to improve various soil chemical parameters as compared to mineral fertilizer. The incorporation of COF and OMW seemed to be more effective in improving soil total N and exchangeable K, while MAN significantly increased available P. All the amendments enhance dissolved organic C, soil respiration, microbial biomass and metabolic quotient as

  4. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Organic chemicals, sampling and... Requirements § 141.24 Organic chemicals, sampling and analytical requirements. (a)-(d) (e) Analyses for the... and 515.1 are in Methods for the Determination of Organic Compounds in Drinking Water,...

  5. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Organic chemicals, sampling and... Requirements § 141.24 Organic chemicals, sampling and analytical requirements. (a)-(d) (e) Analyses for the... and 515.1 are in Methods for the Determination of Organic Compounds in Drinking Water,...

  6. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Organic chemicals, sampling and... Requirements § 141.24 Organic chemicals, sampling and analytical requirements. (a)-(d) (e) Analyses for the... and 515.1 are in Methods for the Determination of Organic Compounds in Drinking Water,...

  7. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Organic chemicals, sampling and... Requirements § 141.24 Organic chemicals, sampling and analytical requirements. (a)-(d) (e) Analyses for the... and 515.1 are in Methods for the Determination of Organic Compounds in Drinking Water,...

  8. Detecting recalcitrant organic chemicals in water with microbial fuel cells and artificial neural networks.

    PubMed

    King, Scott T; Sylvander, Marc; Kheperu, Mekhakhem; Racz, LeeAnn; Harper, Willie F

    2014-11-01

    This study integrates artificial neural network (ANN) processing with microbial fuel cell (MFC)-based biosensing in the detection of three organic pollutants: aldicarb, dimethyl-methylphosphonate (DMMP), and bisphenol-A (BPA). Overall, the use of the ANN proved to be more reliable than direct correlations for the determination of both chemical concentration and type. The ANN output matched the appropriate chemical concentration and type for three different concentrations and throughout a wide range of stepwise tests. Additionally, chemicals dissolved in the acetate-based feed medium (FM) were accurately identified by the ANN even though the acetate masked the pollutants' effects on electrical current. The ANN also accurately revealed the identity of chemical mixtures. This study is the first to incorporate ANN modeling with MFC-based biosensing for the detection and quantification of organic pollutants that are not readily biodegradable. Furthermore, this work provides insight into the flexibility of MFC-based biosensing as it pertains to limits of detection and its applicability to scenarios where mixtures of pollutants and unique solvents are involved. This research effort is expected to serve as a guide for future MFC-based biosensing efforts.

  9. Federal agencies active in chemical industry-related research and development

    SciTech Connect

    1995-09-29

    The Energy Policy Act of 1992 calls for a program to further the commercialization of renewable energy and energy efficient technologies for the industrial sector.. The primary objective of the Office of Industrial Technologies Chemical Industry Team is to work in partnership with the US chemical industry to maximize economic, energy, and environmental benefits through research and development of innovative technologies. This document was developed to inventory organizations within the federal government on current chemical industry-related research and development. While an amount of funding or number of projects specifically relating to chemical industry research and development was not defined in all organizations, identified were about 60 distinct organizations representing 7 cabinet-level departments and 4 independent agencies, with research efforts exceeding $3.5 billion in fiscal year 1995. Effort were found to range from less than $500 thousand per year at the Departments of Agriculture and the Interior to over $100 million per year at the Departments of Commerce, Defense, Energy, and Health and Human Services and the National Aeronautics and Space Administration. The total number of projects in these programs exceeded 10,000. This document is complete to the extent that agencies volunteered information. Additions, corrections, and changes are encouraged and will be incorporated in future revisions.

  10. Sources and Chemical Evolution of Atmospheric Organic Particulate Matter

    NASA Astrophysics Data System (ADS)

    Murphy, Benjamin Neel

    Organic compounds make up a significant fraction of the total composition of atmospheric particles with a diameter of 2.5 mum or less (PM2.5 ) at location throughout the world and seasons throughout the entire year. An understanding of the entire atmospheric PM2.5 system is thus dependent on an adequate understanding of the sources, properties and fate of organic compounds. These species exist in equilibrium between the particulate- and gas-phase. The fraction of the total mass present in each phase is governed by the volatility of individual species. A variety of emission activities are responsible for injecting this organic mass into the atmosphere including vehicle use, biomass burning, energy generation, industrial processing and plat emissions among other sources. After this initial emission atmospheric oxidants may modify the properties of these compounds, especially their volatility, thereby shifting the equilibrium between the particulate- and gas-phase and causing condensation or evaporation. This thesis focuses on modeling these complex phenomena in a chemical transport model (CTM) of the atmosphere. We employ the volatility basis set (VBS) in the CTM, PMCAMx-2008, and evaluate it against ambient measurements. While taking into account recent findings about the volatility distribution of primary organic aerosol (POA) and the multigenerational OH oxidation of the vapors in equilibrium with primary as well as secondary organic aerosol (SOA), we find the model to perform reasonably well for a summertime simulation of the Eastern US (fractional error ≤ 52% and |fractional bias| ≤ 30%) for all sites compared. With this acceptably performing model, we explore the source-receptor relationships of organic aerosol (OA). A three US sites (Pittsburgh, PA; Duke Forest, NC; and New York, NY), and one European site (Paris, FR) the bulk OA behaves very much as a regional pollutant with average transport distances of about 100-500 km before arriving at the receptors

  11. Chemical and electrochemical oxidation of small organic molecules

    NASA Astrophysics Data System (ADS)

    Smart, Marshall C.

    Direct oxidation fuel cells using proton-exchange membrane electrolytes have long been recognized as being an attractive mode of power generation. The current work addresses the electro-oxidation characteristics of a number of potential fuels on Pt-based electrodes which can be used in direct oxidation fuel cells, including hydrocarbons and oxygenated molecules, such as alcohols, formates, ethers, and acetals. Promising alternative fuels which were identified, such as trimethoxymethane and dimethoxymethane, were then investigated in liquid-feed PEM-based fuel cells. In addition to investigating the nature of the anodic electro-oxidation of organic fuels, effort was also devoted to developing novel polymer electrolyte membranes which have low permeability to organic molecules, such as methanol. This research was initiated with the expectation of reducing the extent of fuel crossover from the anode to the cathode in the liquid-feed design fuel cell which results in lower fuel efficiency and performance. Other work involving efforts to improve the performance of direct oxidation fuel cell includes research focused upon improving the kinetics of oxygen reduction. There is continued interest in the identification of new, safe, non-toxic, and inexpensive reagents which can be used in the oxidation of organic compounds. Urea-hydrogen peroxide (UHP), a hydrogen bonded adduct, has been shown to serve as a valuable source of hydrogen peroxide in a range of reactions. UHP has been shown to be ideal for the monohydroxylation of aromatics, including toluene, ethylbenzene, p-xylene, m-xylene, and mesitylene, as well as benzene, in the presence of trifluoromethanesulfonic acid. It was also found that aniline was converted to a mixture containing primarily azobenzene, azoxybenzene and nitrobenzene when reacted with UHP in glacial acetic acid. A number of aniline derivatives have been investigated and it was observed that the corresponding azoxybenzene derivatives could be

  12. Mapping of volatile organic chemicals in New Jersey water systems.

    PubMed

    Cohn, P; Savrin, J; Fagliano, J

    1999-01-01

    To characterize volatile organic chemical (VOC) contamination in public water in New Jersey from 1978 through 1990, detailed GIS maps were developed, along with descriptive text and an associated contaminant database, broken into half-year periods. All water providers that served more than 500 service connections were mapped. Contamination status for nine VOCs, including total trihalomethanes (THMs), was estimated for about 90% of the state's population. Many water systems were partitioned into smaller subsystems in order to map service areas that were more homogeneous with regard to water quality in order to minimize exposure misclassification. Data used for this work included test results taken by the New Jersey Department of Environmental Protection or the water utilities (raw, plant, and distribution system samples), an analysis of probable water use and water flow (based on pumpage, population, system architecture, and advice from the water systems), and information on service area extensions during the period. Using GIS applications, these maps and databases were used to estimate the size of the population exposed to contaminants over time, demonstrating a dramatic decrease in exposed population after the New Jersey Safe Drinking Water Act was signed in 1984.

  13. Nanoenabled microelectromechanical sensor for volatile organic chemical detection

    NASA Astrophysics Data System (ADS)

    Zuniga, Chiara; Rinaldi, Matteo; Khamis, Samuel M.; Johnson, A. T.; Piazza, Gianluca

    2009-06-01

    A nanoenabled gravimetric chemical sensor prototype based on the large scale integration of single-stranded DNA (ss-DNA) decorated single-walled carbon nanotubes (SWNTs) as nanofunctionalization layer for aluminum nitride contour-mode resonant microelectromechanical (MEM) gravimetric sensors has been demonstrated. The capability of two distinct single strands of DNA bound to SWNTs to enhance differently the adsorption of volatile organic compounds such as dinitroluene (simulant for explosive vapor) and dymethyl-methylphosphonate (simulant for nerve agent sarin) has been verified experimentally. Different levels of sensitivity (17.3 and 28 KHz μm2/fg) due to separate frequencies of operation (287 and 450 MHz) on the same die have also been shown to prove the large dynamic range of sensitivity attainable with the sensor. The adsorption process in the ss-DNA decorated SWNTs does not occur in the bulk of the material, but solely involves the surface, which permits to achieve 50% recovery in less than 29 s.

  14. Chemiluminescent chemical sensors for inorganic and organic vapors

    SciTech Connect

    Collins, G.E.; Rose-Pehrsson, S.L.

    1995-12-31

    Chemiluminescent, chemical sensors for inorganic and organic vapors are being investigated via the immobilization of 3-aminophthalhydrazide (luminol) within hydrogels and polymeric, sorbent coatings. The films are supported behind a teflon membrane and positioned in front of a photomultiplier tube, permitting the sensitive detection of numerous toxic vapors. Some selectivity has been tailored into these devices by careful selection of the polymer type, pH and metal catalyst incorporated within the film. The incorporation of luminol and Fe(3) within a polyvinylalcohol hydrogel gave a film with superior sensitivity toward NO{sub 2} (detection limit of 0.46 ppb and a response time on the order of seconds). The use of the hydrogel matrix helped eliminate humidity problems associated with other polymeric films. Other chemiluminescent thin films prepared have demonstrated the detection of ppb levels of SO{sub 2}(g) and hydrazine, N{sub 2}H{sub 4}(g). Recently, the authors have begun investigating the incorporation of a heated Pt filament into the inlet line as a pre-oxidative step prior to passage of the gas stream across the teflon membrane. This has permitted the sensitive detection of ppm levels of CCl{sub 4}(g), CHCl{sub 3}(g) and CH{sub 2}Cl{sub 2}(g).

  15. Isolation and chemical characterization of dissolved and colloidal organic matter

    USGS Publications Warehouse

    Aiken, G.; Leenheer, J.

    1993-01-01

    Commonly used techniques for the concentration and isolation of organic matter from water, such as preparative chromatography, ultrafiltration and reverse osmosis, and the methods used to analyze the organic matter obtained by these methods are reviewed. The development of methods to obtain organic matter that is associated with fractions of the dissolved organic carbon other than humic substances, such as organic bases, hydrophilic organic acids and colloidal organic matter are discussed. Methods specifically used to study dissolved organic nitrogen and dissolved organic phosphorous are also discussed. -from Authors

  16. Chemical and biological sensing with organic thin-film transistors

    NASA Astrophysics Data System (ADS)

    Mabeck, Jeffrey Todd

    Organic thin-film transistors (OTFTs) offer a great deal of promise for applications in chemical and biological sensing where there is a demand for small, portable, and inexpensive sensors. OTFTs have many advantages over other types of sensors, including low-cost fabrication, straightforward miniaturization, simple instrumentation, and inherent signal amplification. This dissertation examines two distinct types of OTFTs: organic field-effect transistors (OFETs) based on pentacene, and organic electrochemical transistors (OECTs) based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The bulk of the previous work on sensing with OFETs has focused on gas sensing, and this dissertation contributes to this body of work by briefly treating the large, reversible response of pentacene OFETs to humidity. However, there are many applications where the analyte of interest must be detected in an aqueous environment rather than a gaseous environment, and very little work has been done in this area for OFETs. Therefore, the integration of pentacene OFETs with microfluidics is treated in detail. Using poly(dimethylsiloxane) (PDMS) microfluidic channels to confine aqueous solutions over the active region of pentacene transistors, it is demonstrated that the current-voltage characteristics remain stable under aqueous flow with a decrease in mobility of ˜30% compared to its value when dry. The operation of PEDOT:PSS transistors is also treated in detail. It is demonstrated that their transistor behavior cannot be attributed solely to a field effect and that ion motion is key to the switching mechanism. It is also demonstrated that simple glucose sensors based on PEDOT:PSS OECTs are sensitive to low glucose concentrations below 1 mM, therefore showing promise for potential application in the field of noninvasive glucose monitoring for diabetic patients using saliva rather than blood samples. Furthermore, a novel microfluidic gating technique has been

  17. Methods in plant foliar volatile organic compounds research1

    PubMed Central

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-01-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant–plant and plant–insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies. PMID:26697273

  18. Methods in plant foliar volatile organic compounds research.

    PubMed

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-12-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant-plant and plant-insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies.

  19. Comparison of InGaAs(100) Grown by Chemical Beam Epitaxy and Metal Organic Chemical Vapor Deposition

    NASA Technical Reports Server (NTRS)

    Williams, M. D.; Greene, A. L.; Daniels-Race, T.; Lum, R. M.

    2000-01-01

    Secondary ion mass spectrometry is used to study the effects of substrate temperature on the composition and growth rate of InGaAs/InP(100) multilayers grown by chemical beam epitaxy, metal-organic chemical vapor deposition and solid source molecular beam epitaxy. The growth kinetics of the material grown by the different techniques are analyzed and compared.

  20. Experts workshop on the ecotoxicological risk assessment of ionizable organic chemicals: Towards a science-based framework for chemical assessment

    EPA Science Inventory

    There is a growing need to develop analytical methods and tools that can be applied to assess the environmental risks associated with charged, polar, and ionisable organic chemicals, such as those used as active pharmaceutical ingredients, biocides, and surface active chemicals. ...

  1. 78 FR 26811 - Dow Chemical Company, Dow TRIGA Research Reactor; License Renewal for the Dow Chemical TRIGA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-08

    ... COMMISSION Dow Chemical Company, Dow TRIGA Research Reactor; License Renewal for the Dow Chemical TRIGA Research Reactor; Supplemental Information and Correction AGENCY: Nuclear Regulatory Commission. ACTION... Chemical TRIGA Research Reactor,'' to inform the public that the NRC is considering issuance of a...

  2. Modeling multiphase migration of organic chemicals in groundwater systems--a review and assessment.

    PubMed Central

    Abriola, L M

    1989-01-01

    Over the past two decades, a number of models have been developed to describe the multiphase migration of organic chemicals in the subsurface. This paper presents the state-of-the-art with regard to such modeling efforts. The mathematical foundations of these models are explored and individual models are presented and discussed. Models are divided into three groups: a) those that assume a sharp interface between the migrating fluids; b) those that incorporate capillarity; and c) those that consider interphase transport of mass. Strengths and weaknesses of each approach are considered along with supporting data for model validation. Future research directions are also highlighted. PMID:2695322

  3. Summaries of FY 1982 research in the chemical sciences

    SciTech Connect

    1982-09-01

    The purpose of this booklet is to help those interested in research supported by the Department of Energy's Division of Chemical Sciences, which is one of six Divisions of the Office of Basic Energy Sciences in the Office of Energy Research. These summaries are intended to provide a rapid means for becoming acquainted with the Chemical Sciences program to members of the scientific and technological public and interested persons in the Legislative and Executive Branches of the Government. Areas of research supported by the Division are to be seen in the section headings, the index and the summaries themselves. Energy technologies which may be advanced by use of the basic knowledge discovered in this program can be seen in the index and again (by reference) in the summaries. The table of contents lists the following: photochemical and radiation sciences; chemical physics; atomic physics; chemical energy; separation and analysis; chemical engineering sciences; offsite contracts; equipment funds; special facilities; topical index; institutional index for offsite contracts; investigator index.

  4. Effects of dissolved organic matter (DOM) on the bioconcentration of organic chemicals in aquatic organisms--a review.

    PubMed

    Haitzer, M; Höss, S; Traunspurger, W; Steinberg, C

    1998-09-01

    Current knowledge on the effects of dissolved organic matter (DOM) on the bioconcentration of organic chemicals in aquatic animals (water fleas, mussels, amphipods and fish) is summarized. A graphical representation of the available data gives an overview of the magnitude of the observed effects. Most of the studies have shown decreases in bioconcentration in the presence of DOM (2 to 98% relative to DOM-free controls). However, at low DOM levels, up to 10 mg/L, also enhancements of bioconcentration due to DOM, ranging from 2 to 303% have been reported. Generally, the change in BCFW (Bioconcentration factor on a wet weight basis) per mg/L DOC was most pronounced at low levels of DOC. The data also show that DOM from different sources with different characteristics and quality can lead to substantial variations in the bioconcentration of organic compounds at comparable levels of DOC. While decreases in bioconcentration have generally been attributed to a lack of bioavailability of DOM-bound chemical, no mechanisms have been proposed to explain increased uptake of xenobiotics caused by DOM.

  5. TOOL FOR MONITORING HYDROPHILIC CONTAMINANTS IN WATER: POLAR ORGANIC CHEMICAL INTEGRATIVE SAMPLER (POCIS)

    EPA Science Inventory

    Global emissions of persistent bioconcentratable organic chemicals have resulted in a wide range of adverse ecological effects. Consequently, industry was led to develop less persistent, more water soluble, polar or hydrophilic organic compounds (HpOCs), which generally have low ...

  6. Organic contaminants in Great Lakes tributaries: Identification of watersheds and chemicals of greatest concern

    EPA Science Inventory

    Trace organic contaminant concentrations in some Great Lakes tributaries indicate potential for adverse effects on aquatic organisms. Chemicals used in agriculture, industry, and households enter surface waters via variety of sources, including urban and agricultural runoff, sewa...

  7. Advanced physical-chemical life support systems research

    NASA Technical Reports Server (NTRS)

    Evanich, Peggy L.

    1988-01-01

    A proposed NASA space research and technology development program will provide adequate data for designing closed loop life support systems for long-duration manned space missions. This program, referred to as the Pathfinder Physical-Chemical Closed Loop Life Support Program, is to identify and develop critical chemical engineering technologies for the closure of air and water loops within the spacecraft, surface habitats or mobility devices. Computerized simulation can be used both as a research and management tool. Validated models will guide the selection of the best known applicable processes and in the development of new processes. For the integration of the habitat system, a biological subsystem would be introduced to provide food production and to enhance the physical-chemical life support functions on an ever-increasing basis.

  8. Chemical and Biological Sensors Based on Organic Electrochemical Transistors

    NASA Astrophysics Data System (ADS)

    Lin, Peng

    Organic thin film transistors (OTFTs) have been explored for sensing applications for several decades due to their many advantages like easy fabrication, low cost, flexibility, and biocompatibility. Among these OTFTs, organic electrochemical transistors (OECTs) have attracted a great deal of interest in recent years since the devices can operate stably in aqueous environment with relatively low working voltages and are suitable for applications in chemical and biological sensing. In this thesis, ion-sensitive properties of OECTs based on poly(3,4- ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) have been systematically studied. It was found that the gate electrode played an important role on the ion-sensitive properties of OECTs. For the devices with Ag/AgCl gate electrode, Nernstian relationships between the shift of gate voltage and the concentrations of cations were obtained. For the devices with Pt and Au gate electrodes, the ion sensitivities were higher than that given by Nernst equation, which could be attributed to the interface between the metal gate electrode and the electrolyte. Moreover, OECTs based on PEDOT:PSS were integrated into flexible microfluidic systems. Then a novel label-free DNA sensor was developed, in which single-stranded DNA probes were immobilized on the surface of Au gate electrode. These devices successfully detected complementary DNA targets at concentrations as low as 1 nM. The detection limit was also extended to 10 pM by pulse-enhanced hybridization process of DNA. OECTs based on PEDOT:PSS were also exploited as cell-based biosensors. Human esophageal squamous epithelial cancer cell lines (KYSE30) and fibroblast cell lines (HFFI) were successfully grown on the surface of PEDOT:PSS film. Then the devices were used for in-vitro monitoring cell activities when the living cells were treated by trypsin and an anti-cancer drug, retinoic acid. It was found that the devices were sensitive to the change of surface charge

  9. Research in the chemical sciences. Summaries of FY 1995

    SciTech Connect

    1995-09-01

    This summary book is published annually to provide information on research supported by the Department of Energy`s Division of Chemical Sciences, which is one of four Divisions of the Office of Basic Energy Sciences in the Office of Energy Research. These summaries provide the scientific and technical public, as well as the legislative and executive branches of the Government, information, either generally or in some depth, about the Chemical Sciences program. Scientists interested in proposing research for support will find the publication useful for gauging the scope of the present basic research program and it`s relationship to their interests. Proposals that expand this scope may also be considered or directed to more appropriate offices. The primary goal of the research summarized here is to add significantly to the knowledge base in which existing and future efficient and safe energy technologies can evolve. As a result, scientific excellence is a major criterion applied in the selection of research supported by the Division of Chemical Sciences, but another important consideration is emphasis on science that is advancing in ways that will produce new information related to energy.

  10. Summer Research Institute Interfacial and Condensed Phase Chemical Physics

    SciTech Connect

    Barlow, Stephan E.

    2004-10-01

    Pacific Northwest National Laboratory (PNNL) hosted its first annual Summer Research Institute in Interfacial and Condensed Phase Chemical Physics from May through September 2004. During this period, fourteen PNNL scientists hosted sixteen young scientists from eleven different universities. Of the sixteen participants, fourteen were graduate students; one was transitioning to graduate school; and one was a university faculty member.

  11. Chemical and Metallurgy Research (CMR) Sample Tracking System Design Document

    SciTech Connect

    Bargelski, C. J.; Berrett, D. E.

    1998-09-01

    The purpose of this document is to describe the system architecture of the Chemical and Metallurgy Research (CMR) Sample Tracking System at Los Alamos National Laboratory. During the course of the document observations are made concerning the objectives, constraints and limitations, technical approaches, and the technical deliverables.

  12. Facts and Figures for Chemical Research and Development.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1983

    1983-01-01

    Discusses data on chemical research and development (R&D). Areas addressed include sources of R&D funds, R&D spending by the federal government and by industry, and sources of academic R&D funds. provides charts and tables and data on scientists/engineers, budgets, comparisons between applied/basic R&D, abstracts in chemical…

  13. Publication Trends in Model Organism Research

    PubMed Central

    Dietrich, Michael R.; Ankeny, Rachel A.; Chen, Patrick M.

    2014-01-01

    In 1990, the National Institutes of Health (NIH) gave some organisms special status as designated model organisms. This article documents publication trends for these NIH-designated model organisms over the past 40 years. We find that being designated a model organism by the NIH does not guarantee an increasing publication trend. An analysis of model and nonmodel organisms included in GENETICS since 1960 does reveal a sharp decline in the number of publications using nonmodel organisms yet no decline in the overall species diversity. We suggest that organisms with successful publication records tend to share critical characteristics, such as being well developed as standardized, experimental systems and being used by well-organized communities with good networks of exchange and methods of communication. PMID:25381363

  14. Organic matter in carbonaceous meteorites: past, present and future research.

    PubMed

    Sephton, Mark A

    2005-12-15

    Carbonaceous meteorites are fragments of ancient asteroids that have remained relatively unprocessed since the formation of the Solar System. These carbon-rich objects provide a record of prebiotic chemical evolution and a window on the early Solar System. Many compound classes are present reflecting a rich organic chemical environment during the formation of the planets. Recent theories suggest that similar extraterrestrial organic mixtures may have acted as the starting materials for life on Earth.

  15. [Recent results in research on oscillatory chemical reactions].

    PubMed

    Poros, Eszter; Kurin-Csörgei, Krisztina

    2014-01-01

    The mechanisms of the complicated periodical phenomenas in the nature (e.g. hearth beat, sleep cycle, circadian rhythms, etc) could be understood with using the laws of nonlinear chemical systems. In this article the newest result in the research of the subfield of nonlinear chemical dynamics aimed at constructing oscillatory chemical reactions, which are novel either in composition or in configuration, are presented. In the introductory part the concept of chemical periodicity is defined, then the forms as it can appear in time and space and the methods of their study are discussed. Detailed description of the experimental work that has resulted in two significant discoveries is provided. A method was developed to design pH-oscillators which are capable of operating under close conditions. The batch pH-oscillators are more convenient to use in some proposed applications than the equivalent CSTR variant. A redox oscillator that is new in composition was found. The permanganate oxidation of some amino acids was shown to take place according to oscillatory kinetics in a narrow range of the experimental parameters. The KMnO4 - glycine - Na2HPO4 system represents the first example in the family of manganese based oscillators where amino acids is involved. In the conclusion formal analogies between the simple chemical and some more complicated biological oscillatory phenomena are mentioned and the possibility of modeling periodic processes with the use of information gained from the studies of chemical oscillations is pointed out.

  16. Soil and water losses on citrus orchards under Mediterranean Type Ecosystems. Organic against chemical farming

    NASA Astrophysics Data System (ADS)

    Cerdà, A.; Bodí, M. B.; García-Orenes, F.

    2012-04-01

    Soil erosion in Mediterranean Type Ecosystems is highly dependent on the land use and land management (Cerdà et al., 2010). This is due mainly to the impact of agriculture (Cerdà et al., 2009) as a consequence of tillage and the use of herbicides. Both strategies contribute to a reduction in the vegetation cover and the soil biological activities (García-Orenes et al., 2009). The impact of soil erosion on agronomic productivity and environmental quality is widely known (Lal, 1998), although little has been researched in the Mediterranean. The impact of agriculture on soil erosion and water losses in the Mediterranean basin has been studied in olive orchards (Gómez, 2004); vineyards (Ramos and Martínez Casasnovas, 2004), citrus (Cerdà et al., 2009), cereals (De Santisteban et al., (2005), and the high erosion rates were found to be related to the land management and land use (García Ruiz, 2010). The current Mediterranean agriculture is based on tillage and herbicides, which contribute to high soil and water losses. The development of sustainable agriculture practices is a challenge for farmers, technicians and politicians. Organic farming use strategies to reduce the soil losses and develop new strategies of soil conservation. Moreover organic farming recover the soil fertility and biodiversity (Maeder et al., 2002). Organic farming is growing in the Mediterranean but little is know about his effect on soil conservation. There is a lack in the knowledge of how organic farming affect the soil properties and, there is no information on his effect on soil and water losses. This paper aims to measure the impact of organic farming on soil and water losses. 10 plots of 1 x 0,5 m were selected in a chemically managed farm in Montesa (Eastern Spain) and 10 plots in a nearby organic farming managed farm. Both of them were cultivated with citrus. The ten paired plots were monitored. After earch rainfall event the sediment and water collected were measured and analized

  17. Review of laboratory-based terrestrial bioaccumulation assessment approaches for organic chemicals: Current status and future possibilities.

    PubMed

    Hoke, Robert; Huggett, Duane; Brasfield, Sandra; Brown, Becky; Embry, Michelle; Fairbrother, Anne; Kivi, Michelle; Paumen, Miriam Leon; Prosser, Ryan; Salvito, Dan; Scroggins, Rick

    2016-01-01

    In the last decade, interest has been renewed in approaches for the assessment of the bioaccumulation potential of chemicals, principally driven by the need to evaluate large numbers of chemicals as part of new chemical legislation, while reducing vertebrate test organism use called for in animal welfare legislation. This renewed interest has inspired research activities and advances in bioaccumulation science for neutral organic chemicals in aquatic environments. In January 2013, ILSI Health and Environmental Sciences Institute convened experts to identify the state of the science and existing shortcomings in terrestrial bioaccumulation assessment of neutral organic chemicals. Potential modifications to existing laboratory methods were identified, including areas in which new laboratory approaches or test methods could be developed to address terrestrial bioaccumulation. The utility of "non-ecotoxicity" data (e.g., mammalian laboratory data) was also discussed. The highlights of the workshop discussions are presented along with potential modifications in laboratory approaches and new test guidelines that could be used for assessing the bioaccumulation of chemicals in terrestrial organisms.

  18. Chemical, green and organic manure effects on chemical properties on a savannah oxisol and on corn under conventional tillage and no-tillage

    NASA Astrophysics Data System (ADS)

    Mannigel, Anny R.; Alves, Marlene C.; Valério Filho, Walter V.

    2015-04-01

    Modern agriculture, in general, has always been based on the concept that natural resources are endless; however, this concept is changing. Concern for the environment is increasingly becoming part of farming practices, either by the awareness of society, or because the high cost of fertilizers or even the exhaustion of soils. The objective of this research was to evaluate the effects of the green manure and mineral fertilizer and/or organic manure and, on the chemical properties of an Oxisol, on "Savannah" (cerrado) area in Mato Grosso do Sul-Brazil, cultivated with corn (Zea mays L.) on the following management conditions: no-tillage and conventional tillage, on area previously under pasture (Brachiaria decumbens). The experimental design was a randomized blocks and the tested treatments were: control (without organic manure or chemical fertilizer); chemical fertilizer, as recommended for the culture and based on the chemical soil analysis; organic manure (cow manure); organic manure + half of the mineral fertilizer recommended rate; and the green manure Crotalaria juncea and Pennisetum americanum. The chemical analyses were the soil chemical analysis to the intent of soil fertility. Corn yield was evaluated. The collect of soil samples were realized in depths of 0.00-0.05 m and 0.05-0.10 m and 0.10-0.20 m. The organic manure and the organic manure + half of the mineral recommended rate increased P, Ca, Mg, K and Organic Matter in the first depth (0.00 - 0.05 m). These treatments also increased K and Mg at the second depth analyzed (0.05 - 0.10 m) and K in the depth from 0.10 - 0.20 m. Under conventional tillage management presents better crop results with an average grain yield of 3649 kg ha-1 versus 2374 kg ha-1 obtained under no-tillage. The use of chemical fertilizer, organic manure + half of the mineral recommended rate, Crotalaria juncea, organic manure and Pennisetum americanum increased corn yield by 84, 79, 58, 44 and 41 %, respectively.

  19. Organic Research Activities of the USDA’s Agricultural Research Service

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic research is a vital and ongoing part of the overall ARS research portfolio and occurs at approximately 20 % of ARS research locations across the United States. The vision for ARS organic agriculture research is to help the organic industry overcome the challenges it faces related to producti...

  20. Volatile organic chemical emissions from carpets. Final report

    SciTech Connect

    Hodgson, A.T.; Wooley, J.D.; Daisey, J.M.

    1992-04-01

    The primary objective of this research, was to measure the emission rates of selected individual VOC, including low molecular-weight aldehydes, released by samples of four new carpets that are typical of the major types of carpets used in residences, schools and offices. The carpet samples were collected directly from the manufacturers` mills and packaged to preserve their chemical integrity. The measurements of the concentrations and emission rates of these compounds were made under simulated indoor conditions in a 20-M{sup 3} environmental chamber designed specifically for investigations of VOC. The measurements were conducted over a period of one week following the installation of the carpet samples in the chamber. Duplicate experiments were conducted for one carpet. In addition, the concentrations and emission rates of VOC resulting from the installation of a new carpet in a residence were measured over a period of seven weeks. The stabilities of the week-long ventilation rates and temperatures were one percent relative standard deviation. The four carpets emitted a variety of VOC, 40 of which were positively identified. Eight of these were considered to be dominant. They were (in order of chromatographic retention time) formaldehyde, vinyl acetate, 2,2,4-trimethylpentane (isooctane), 1,2-propanediol (propylene glycol), styrene, 2-ethyl-l-hexanol, 4-phenylcyclohexene (4-PCH), and 2,6 di-tert-butyl-4-methylphenol (BHT). With the exception of formaldehyde, only limited data are available on the toxicity and irritancy of these compounds at low concentrations. Therefore, it is difficult to determine at this time the potential magnitude of the health and comfort effects that may occur among the population from exposures to emissions from new carpets. The concentrations and emission rates of most compounds decreased rapidly over the first 12 h of the experiments.

  1. Identifying new persistent and bioaccumulative organics among chemicals in commerce.

    PubMed

    Howard, Philip H; Muir, Derek C G

    2010-04-01

    The goal of this study was to identify commercial chemicals that might be persistent and bioaccumulative (P&B) and that were not being considered in current Great Lakes, North American, and Arctic contaminant measurement programs. We combined the Canadian Domestic Substance List (DSL), a list of 3059 substances of "unknown or variable composition complex reaction products and biological materials" (UVCBs), and the U.S. Environmental Protection Agency (U.S. EPA) Toxic Substances Control Act (TSCA) Inventory Update Rule (IUR) database for years 1986, 1990, 1994, 1998, 2002, and 2006 yielding a database of 22263 commercial chemicals. From that list, 610 chemicals were identified by estimates from U.S EPA EPISuite software and using expert judgment. This study has yielded some interesting and probable P&B chemicals that should be considered for further study. Recent studies, following up our initial reports and presentations on this work, have confirmed the presence of many of these chemicals in the environment.

  2. PREDICTING SOIL SORPTION COEFFICIENTS OF ORGANIC CHEMICALS USING A NEURAL NETWORK MODEL

    EPA Science Inventory

    The soil/sediment adsorption partition coefficient normalized to organic carbon (Koc) is extensively used to assess the fate of organic chemicals in hazardous waste sites. Several attempts have been made to estimate the value of Koc from chemical structure ...

  3. Spatial and Temporal Trends of Persistent Organic Chemicals with Emphasis on Brominated Flame Retardants

    EPA Science Inventory

    Rapid growth in chemical and agrochemical industries during the past century have resulted in the release of large numbers of persistent organic chemicals (POCs) into the environment. Since POCs are prevalent in air, water, soil and tissue of organisms throughout the world and r...

  4. SEDIMENT TOXICITY EVALUATION OF EXTRACTS OF ORGANIC CHEMICALS FROM CONTAMINATED SEDIMENTS: EVALUATION OF AN EXPERIMENTAL APPROACH

    EPA Science Inventory

    Most solid-phase sediment TIE techniques for organic chemicals have been focused on the addition of sorbents, such as the carbonaceous resin, Ambersorb 1500. While these sorbents have shown some promise for indicating when non-polar organic chemicals may be contributing to toxici...

  5. Activist Research and Organizing: Blurring the Boundaries, Challenging the Binaries

    ERIC Educational Resources Information Center

    Choudry, Aziz

    2014-01-01

    This article draws from ongoing research into the practices and processes of activist researchers. It discusses social relations of knowledge production located outside of academia with/in social movement milieus. Focusing on the politics of research in people's organizations and social movement organizations in the Philippines, it builds on…

  6. Multispecies QSAR modeling for predicting the aquatic toxicity of diverse organic chemicals for regulatory toxicology.

    PubMed

    Singh, Kunwar P; Gupta, Shikha; Kumar, Anuj; Mohan, Dinesh

    2014-05-19

    The research aims to develop multispecies quantitative structure-activity relationships (QSARs) modeling tools capable of predicting the acute toxicity of diverse chemicals in various Organization for Economic Co-operation and Development (OECD) recommended test species of different trophic levels for regulatory toxicology. Accordingly, the ensemble learning (EL) approach based classification and regression QSAR models, such as decision treeboost (DTB) and decision tree forest (DTF) implementing stochastic gradient boosting and bagging algorithms were developed using the algae (P. subcapitata) experimental toxicity data for chemicals. The EL-QSAR models were successfully applied to predict toxicities of wide groups of chemicals in other test species including algae (S. obliguue), daphnia, fish, and bacteria. Structural diversity of the selected chemicals and those of the end-point toxicity data of five different test species were tested using the Tanimoto similarity index and Kruskal-Wallis (K-W) statistics. Predictive and generalization abilities of the constructed QSAR models were compared using statistical parameters. The developed QSAR models (DTB and DTF) yielded a considerably high classification accuracy in complete data of model building (algae) species (97.82%, 99.01%) and ranged between 92.50%-94.26% and 92.14%-94.12% in four test species, respectively, whereas regression QSAR models (DTB and DTF) rendered high correlation (R(2)) between the measured and model predicted toxicity end-point values and low mean-squared error in model building (algae) species (0.918, 0.15; 0.905, 0.21) and ranged between 0.575 and 0.672, 0.18-0.51 and 0.605-0.689 and 0.20-0.45 in four different test species. The developed QSAR models exhibited good predictive and generalization abilities in different test species of varied trophic levels and can be used for predicting the toxicities of new chemicals for screening and prioritization of chemicals for regulation.

  7. Collaboration in a Multidisciplinary, Distributed Research Organization: A Case Study

    ERIC Educational Resources Information Center

    Duysburgh, Pieter; Naessens, Kris; Konings, Wim; Jacobs, An

    2012-01-01

    Collaboration has become a main characteristic of academic research today. New forms of research organizations, colaboratories, have come to the fore, with distributed research centres as their most complex example. In this study, we aim to provide some insight into the collaboration strategies of researchers in their daily researching activities…

  8. Sediment microbial fuel cell prefers to degrade organic chemicals with higher polarity.

    PubMed

    Xia, Chunyu; Xu, Meiying; Liu, Jin; Guo, Jun; Yang, Yonggang

    2015-08-01

    By operating a SMFC in heavily contaminated sediment and analyzing its global organic chemical degradation profile, this study showed a brief trend that SMFC prefers to stimulate the degradation of organic chemicals with higher polarity. As a comparison, adding nitrate as a microbial respiration-based sediment remediation strategy preferred lower polarity chemicals. Both SMFC and nitrate reactors showed high degradation capacity in benzene homologs. These results provide crucial information for the selective and proper application of SMFC in bioremediation.

  9. Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: January--March 1997

    SciTech Connect

    Jubin, R.T.

    1998-01-01

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division (CTD) at Oak Ridge National Laboratory (ORNL) during the period January--March 1997. Created in March 1997 when the CTD Chemical Development and Energy Research sections were combined, the Chemical and Energy Research Section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within seven major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Separations and Materials Synthesis, Solution Thermodynamics, and Biotechnology Research. The name of a technical contact is included with each task described in the report, and readers are encouraged to contact these individuals if they need additional information.

  10. Retrospective exposure assessment in a chemical research and development facility.

    PubMed

    Chen, Yu-Cheng; Ramachandran, Gurumurthy; Alexander, Bruce H; Mandel, Jeffrey H

    2012-02-01

    The objective of this exposure assessment was to reconstruct cumulative historical exposures for workers who have been exposed to multiple chemicals and chemical groups to better understand a cluster of brain cancers within a research and development lab. Chemicals of interest, including acrylates, bis-chloromethyl ether (BCME), chloromethyl methyl ether (CMME), isothiazolones and nitrosoamines, were selected on the basis of the plausibility of penetrating the blood-brain barrier and the uniqueness of the chemical's biological activity. In a complicated exposure setting such as a chemical R&D facility, multiple exposure estimation methods were needed. First, similarly exposure groups (SEGs) were created for these materials based on department group, time period of the department's existence and function associated with job titles. A probabilistic framework for assessing exposures was developed using Bayesian analysis of historical monitoring data, mathematical exposure modeling and professional judgments of current and former industrial hygienists at the facility were used to reconstruct the exposure history for acrylates, BCME and CMME for each SEG over the time period of interest. Since sufficient measurement data for isothiazolones and nitrosoamines were not available, the exposure histories for each SEG for these chemicals were estimated. This was done using objective formaldehyde levels and subjective employee interviews. The interviews assessed workplace determinants of exposure as distinct surrogates for estimating inhalation and dermal exposures. The exposure assessments by these methods were compared against each other to estimate the potential for exposure misclassification. A job exposure matrix (JEM) was constructed that contained the exposures obtained from above multiple approaches for each of these chemical groups for each SEG for each year of interest. The combination of methods used in this work is a unique and potentially helpful framework that

  11. The role of chemical engineering in medicinal research including Alzheimer's.

    PubMed

    Kontogeorgis, Georgios M

    2015-01-01

    Various disciplines of chemical engineering, especially thermodynamics and kinetics, play an important role in medicinal research and this has been particularly recognized during the last 10-15 years (von Stockar and van der Wielen, J Biotechnol 59:25, 1997; Prausnitz, Fluid Phase Equilib 53:439, 1989; Prausnitz, Pure Appl Chem 79:1435, 2007; Dey and Prausnitz, Ind Eng Chem Res 50:3, 2011; Prausnitz, J Chem Thermodynamics 35:21, 2003; Tsivintzelis et al. AIChE J 55:756, 2009). It is expected that during the twenty-first century chemical engineering and especially thermodynamics can contribute as significantly to the life sciences development as it has been done with the oil and gas and chemical sectors in the twentieth century. Moreover, it has during the recent years recognized that thermodynamics can help in understanding diseases like human cataract, sickle-cell anemia, Creuzfeldt-Jacob ("mad cow" disease), and Alzheimer's which are connected to "protein aggregation." Several articles in the Perspectives section of prominent chemical engineering journals have addressed this issue (Hall, AIChE J 54:1956, 2008; Vekilov, AIChE J 54:2508, 2008). This work reviews recent applications of thermodynamics (and other areas of chemical engineering) first in drug development and then in the understanding of the mechanism of Alzheimer's and similar diseases.

  12. Quarterly Progress Report for the Chemical and Energy Research Section of the Chemical Technology Division: January-March 1998

    SciTech Connect

    Jubin, R.T.

    1999-03-01

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period January-March 1998. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within nine major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Biotechnology, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnology Research, and Molecular Studies.

  13. A Study of Organic Chemical Reactions in Microemulsions.

    DTIC Science & Technology

    1984-10-24

    organic synthesis were investigated. The first involved a delineation of the ability of microemulsions to catalyze synthetically useful reactions of water...microemulsions in organic synthesis . We also began the design and synthesis of turnover catalysts for carbon and phosphorus ester hydrolysis. Originator...furnished key words include: microemulsions, organic synthesis , microemulsions, reactive site, microemulsion, destructible (cleavable) surfactant-based, destructible (cleavable) surfactants, turnover catalysts.

  14. Chemical Inventory Management at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Kraft, Shirley S.; Homan, Joseph R.; Bajorek, Michael J.; Dominguez, Manuel B.; Smith, Vanessa L.

    1997-01-01

    The Chemical Management System (CMS) is a client/server application developed with Power Builder and Sybase for the Lewis Research Center (LeRC). Power Builder is a client-server application development tool, Sybase is a Relational Database Management System. The entire LeRC community can access the CMS from any desktop environment. The multiple functions and benefits of the CMS are addressed.

  15. Progress Report for the Chemical and Energy Research Section of the Chemical Technology Division: July-December 1998

    SciTech Connect

    Jubin, R.T.

    1999-06-01

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period July-December 1998. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications.

  16. Quarterly Progress Report for the Chemical and Energy Research Section of the Chemical Technology Division: April-June 1998

    SciTech Connect

    Jubin, R.T.

    1999-04-01

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during th eperiod April-June 1998. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications.

  17. Space Chemical Propulsion Test Facilities at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Urasek, Donald C.; Calfo, Frederick D.

    1993-01-01

    The NASA Lewis Research Center, located in Cleveland, Ohio, has a number of space chemical propulsion test facilities which constitute a significant national space testing resource. The purpose of this paper is to make more users aware of these test facilities and to encourage their use through cooperative agreements between the government, industry, and universities. Research which is of interest to the government is especially encouraged and often can be done in a cooperative manner that best uses the resources of all parties. An overview of the Lewis test facilities is presented.

  18. 75 FR 15675 - Professional Research Experience Program in Chemical Science and Technology Laboratory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... National Institute of Standards and Technology Professional Research Experience Program in Chemical Science...) Chemical Science and Technology Laboratory (CSTL) announces that the Professional Research Experience... Research and Standards--11.609. Program Description: The National Institute of Standards and...

  19. Do Human Milk Concentrations of Persistent Organic Chemicals Really Decline During Lactation? Chemical Concentrations During Lactation and Milk/Serum Partitioning

    PubMed Central

    LaKind, Judy S.; Berlin, Cheston M.; Sjödin, Andreas; Turner, Wayman; Wang, Richard Y.; Needham, Larry L.; Paul, Ian M.; Stokes, Jennifer L.; Naiman, Daniel Q.; Patterson, Donald G.

    2009-01-01

    Background Conventional wisdom regarding exposures to persistent organic chemicals via breast-feeding assumes that concentrations decline over the course of lactation and that the mother’s body burden reflects her cumulative lifetime exposure. Two important implications stemming from these lines of thought are, first, that assessments of early childhood exposures should incorporate decreasing breast milk concentrations over lactation; and, second, that there is little a breast-feeding mother can do to reduce her infant’s exposures via breast-feeding because of the cumulative nature of these chemicals. Objectives We examined rates of elimination and milk/serum partition coefficients for several groups of persistent organic chemicals. Methods We collected simultaneous milk and blood samples of 10 women at two times postpartum and additional milk samples without matching blood samples. Results Contrary to earlier research, we found that lipid-adjusted concentrations of polybrominated diphenyl ethers, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans, and organochlorine pesticides in serum and milk do not consistently decrease during lactation and can increase for some women. Published research has also suggested an approximate 1:1 milk/serum relationship (lipid adjusted) on a population basis for 2,3,7,8-tetrachlorodibenzo-p-dioxin; however, our results suggest a more complex relationship for persistent, lipophilic chemicals with the milk/serum relationship dependent on chemical class. Conclusions Decreases in concentration of lipophilic chemicals on a lipid-adjusted basis during lactation should no longer be assumed. Thus, the concept of pumping and discarding early milk as means of reducing infant exposure is not supported. The hypothesis that persistent lipophilic chemicals, on a lipid-adjusted basis, have consistent concentrations across matrices is likely too simplistic. PMID:20019916

  20. Characterization of organic chemical contaminants in sediments from Jobos Bay, Puerto Rico.

    PubMed

    Pait, Anthony S; Whitall, David R; Dieppa, Angel; Newton, Sarah E; Brune, Lia; Caldow, Chris; Mason, Andrew L; Apeti, Dennis A; Christensen, John D

    2012-08-01

    Jobos Bay, located on the southeastern coast of Puerto Rico, contains a variety of habitats including mangroves, seagrass meadows, and coral reefs. The watershed surrounding the bay includes a number of towns, agricultural areas, and the Jobos Bay National Estuarine Research Reserve (NERR). Jobos Bay and the surrounding watershed are part of a Conservation Effects Assessment Project (CEAP), involving the Jobos Bay NERR, the US Department of Agriculture, and the National Oceanic and Atmospheric Administration (NOAA) to assess the benefits of agricultural best management practices (BMPs) on the terrestrial and marine environments. As part of the Jobos Bay CEAP, NOAA collected sediment samples in May 2008 to characterize over 130 organic chemical contaminants. This paper presents the results of the organic contaminant analysis. The organic contaminants detected in the sediments included polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, and the pesticide DDT. PAHs at one site in the inner bay near a boat yard were significantly elevated; however, all organic contaminant classes measured were below NOAA sediment quality guidelines that would have indicated that impacts were likely. The results of this work provide an important baseline assessment of the marine environment that will assist in understanding the benefits of implementing BMPs on water quality in Jobos Bay.

  1. Chemical characterization and physico-chemical properties of aerosols at Villum Research Station, Greenland during spring 2015

    NASA Astrophysics Data System (ADS)

    Glasius, M.; Iversen, L. S.; Svendsen, S. B.; Hansen, A. M. K.; Nielsen, I. E.; Nøjgaard, J. K.; Zhang, H.; Goldstein, A. H.; Skov, H.; Massling, A.; Bilde, M.

    2015-12-01

    The effects of aerosols on the radiation balance and climate are of special concern in Arctic areas, which have experienced warming at twice the rate of the global average. As future scenarios include increased emissions of air pollution, including sulfate aerosols, from ship traffic and oil exploration in the Arctic, there is an urgent need to obtain the fundamental scientific knowledge to accurately assess the consequences of pollutants to environment and climate. In this work, we studied the chemistry of aerosols at the new Villum Research Station (81°36' N, 16°40' W) in north-east Greenland during the "inauguration campaign" in spring 2015. The chemical composition of sub-micrometer Arctic aerosols was investigated using a Soot Particle Time-of-Flight Aerosol Mass Spectrometer (SP-ToF-AMS). Aerosol samples were also collected on filters using both a high-volume sampler and a low-volume sampler equipped with a denuder for organic gases. Chemical analyses of filter samples include determination of inorganic anions and cations using ion-chromatography, and analysis of carboxylic acids and organosulfates of anthropogenic and biogenic origin using ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). Previous studies found that organosulfates constitute a surprisingly high fraction of organic aerosols during the Arctic Haze period in winter and spring. Investigation of organic molecular tracers provides useful information on aerosol sources and atmospheric processes. The physico-chemical properties of Arctic aerosols are also under investigation. These measurements include particle number size distribution, water activity and surface tension of aerosol samples in order to deduct information on their hygroscopicity and cloud-forming potential. The results of this study are relevant to understanding aerosol sources and processes as well as climate effects in the Arctic, especially during the Arctic haze

  2. Temperature response of litter and soil organic matter decomposition is determined by chemical composition of organic material.

    PubMed

    Erhagen, Björn; Öquist, Mats; Sparrman, Tobias; Haei, Mahsa; Ilstedt, Ulrik; Hedenström, Mattias; Schleucher, Jürgen; Nilsson, Mats B

    2013-12-01

    The global soil carbon pool is approximately three times larger than the contemporary atmospheric pool, therefore even minor changes to its integrity may have major implications for atmospheric CO2 concentrations. While theory predicts that the chemical composition of organic matter should constitute a master control on the temperature response of its decomposition, this relationship has not yet been fully demonstrated. We used laboratory incubations of forest soil organic matter (SOM) and fresh litter material together with NMR spectroscopy to make this connection between organic chemical composition and temperature sensitivity of decomposition. Temperature response of decomposition in both fresh litter and SOM was directly related to the chemical composition of the constituent organic matter, explaining 90% and 70% of the variance in Q10 in litter and SOM, respectively. The Q10 of litter decreased with increasing proportions of aromatic and O-aromatic compounds, and increased with increased contents of alkyl- and O-alkyl carbons. In contrast, in SOM, decomposition was affected only by carbonyl compounds. To reveal why a certain group of organic chemical compounds affected the temperature sensitivity of organic matter decomposition in litter and SOM, a more detailed characterization of the (13) C aromatic region using Heteronuclear Single Quantum Coherence (HSQC) was conducted. The results revealed considerable differences in the aromatic region between litter and SOM. This suggests that the correlation between chemical composition of organic matter and the temperature response of decomposition differed between litter and SOM. The temperature response of soil decomposition processes can thus be described by the chemical composition of its constituent organic matter, this paves the way for improved ecosystem modeling of biosphere feedbacks under a changing climate.

  3. Prediction of organ toxicity endpoints by QSAR modeling based on precise chemical-histopathology annotations.

    PubMed

    Myshkin, Eugene; Brennan, Richard; Khasanova, Tatiana; Sitnik, Tatiana; Serebriyskaya, Tatiana; Litvinova, Elena; Guryanov, Alexey; Nikolsky, Yuri; Nikolskaya, Tatiana; Bureeva, Svetlana

    2012-09-01

    The ability to accurately predict the toxicity of drug candidates from their chemical structure is critical for guiding experimental drug discovery toward safer medicines. Under the guidance of the MetaTox consortium (Thomson Reuters, CA, USA), which comprised toxicologists from the pharmaceutical industry and government agencies, we created a comprehensive ontology of toxic pathologies for 19 organs, classifying pathology terms by pathology type and functional organ substructure. By manual annotation of full-text research articles, the ontology was populated with chemical compounds causing specific histopathologies. Annotated compound-toxicity associations defined histologically from rat and mouse experiments were used to build quantitative structure-activity relationship models predicting subcategories of liver and kidney toxicity: liver necrosis, liver relative weight gain, liver lipid accumulation, nephron injury, kidney relative weight gain, and kidney necrosis. All models were validated using two independent test sets and demonstrated overall good performance: initial validation showed 0.80-0.96 sensitivity (correctly predicted toxic compounds) and 0.85-1.00 specificity (correctly predicted non-toxic compounds). Later validation against a test set of compounds newly added to the database in the 2 years following initial model generation showed 75-87% sensitivity and 60-78% specificity. General hepatotoxicity and nephrotoxicity models were less accurate, as expected for more complex endpoints.

  4. Integrating Qualitative and Quantitative Research in Organizations.

    DTIC Science & Technology

    1981-07-01

    phenomenological approaches at the subjective end of the continuum. A few researchers have suggested ways in which quantitative and qualitative methods may be...Lofland, lq76), symbolic interactionism (Blumer, 1969), ethnomethodology (Turner, 1974), existentialism (Douglas & Johnson, 1977), and phenomenology ...orienting perspectives. Although most qualitative research will use some form of participant observation, those taking a phenomenological approach which

  5. Expatriate Training in International Nongovernmental Organizations: A Model for Research

    ERIC Educational Resources Information Center

    Chang, Wei-Wen

    2005-01-01

    In light of the massive tsunami relief efforts that were still being carried out by humanitarian organizations around the world when this article went to press, this article points out a lack of human resources development research in international nongovernmental organizations (INGOs) and proposes a conceptual model for future empirical research.…

  6. Prediction of the rodent carcinogenicity of organic compounds from their chemical structures using the FALS method.

    PubMed Central

    Moriguchi, I; Hirano, H; Hirono, S

    1996-01-01

    Fuzzy adaptive least-squares (FALS), a pattern recognition method recently developed in our laboratory for correlating structure with activity rating, was used to generate quantitative structure-activity relationship (QSAR) models on the carcinogenicity of organic compounds of several chemical classes. Using the predictive models obtained from the chemical class-based FALS QSAR approach, the rodent carcinogenicity or noncarcinogenicity of a group of organic chemicals currently being tested by the U.S. National Toxicology Program was estimated from their chemical structures. PMID:8933054

  7. Title III section 313 release reporting guidance: Estimating chemical releases from electrodeposition of organic coatings

    SciTech Connect

    Not Available

    1988-01-01

    Appliers of organic coatings via electrodeposition (EDP) may be required to report annually any releases to the environment of certain chemicals regulated under Section 313, Title III, of the Superfund Amendments and Reauthorization Act (SARA) of 1986. The document has been developed to assist appliers of organic coatings in the completion of Part III (Chemical Specific Information) of the Toxic Chemical Release Inventory Reporting Form. Included herein is general information on toxic chemicals used and process wastes generated, along with several examples to demonstrate the types of data needed and various methodologies available for estimating releases.

  8. Title III section 313 release reporting guidance: Estimating chemical releases from spray application of organic coatings

    SciTech Connect

    Not Available

    1988-01-01

    Spray applicators of organic coatings may be required to report annually any releases to the environment of certain chemicals regulated under Section 313, Title III, of the Superfund Amendments and Reauthorization Act (SARA) of 1986. The document has been developed to assist appliers of organic coatings in the completion of Part III (Chemical Specific Information) of the Toxic Chemical Release Inventory Reporting Form. Included herein is general information on toxic chemicals used and process wastes generated, along with several examples to demonstrate the types of data needed and various methodologies available for estimating releases.

  9. Chemical contaminants on DOE lands and selection of contaminant mixtures for subsurface science research

    SciTech Connect

    Riley, R.G.; Zachara, J.M. )

    1992-04-01

    This report identifies individual contaminants and contaminant mixtures that have been measured in the ground at 91 waste sites at 18 US Department of Energy (DOE) facilities within the weapons complex. The inventory of chemicals and mixtures was used to identify generic chemical mixtures to be used by DOE's Subsurface Science Program in basic research on the subsurface geochemical and microbiological behavior of mixed contaminants (DOE 1990a and b). The generic mixtures contain specific radionuclides, metals, organic ligands, organic solvents, fuel hydrocarbons, and polychlorinated biphenyls (PCBs) in various binary and ternary combinations. The mixtures are representative of in-ground contaminant associations at DOE facilities that are likely to exhibit complex geochemical behavior as a result of intercontaminant reactions and/or microbiologic activity stimulated by organic substances. Use of the generic mixtures will focus research on important mixed contaminants that are likely to be long-term problems at DOE sites and that will require cleanup or remediation. The report provides information on the frequency of associations among different chemicals and compound classes at DOE waste sites that require remediation.

  10. Chemical contaminants on DOE lands and selection of contaminant mixtures for subsurface science research

    SciTech Connect

    Riley, R.G.; Zachara, J.M.

    1992-04-01

    This report identifies individual contaminants and contaminant mixtures that have been measured in the ground at 91 waste sites at 18 US Department of Energy (DOE) facilities within the weapons complex. The inventory of chemicals and mixtures was used to identify generic chemical mixtures to be used by DOE`s Subsurface Science Program in basic research on the subsurface geochemical and microbiological behavior of mixed contaminants (DOE 1990a and b). The generic mixtures contain specific radionuclides, metals, organic ligands, organic solvents, fuel hydrocarbons, and polychlorinated biphenyls (PCBs) in various binary and ternary combinations. The mixtures are representative of in-ground contaminant associations at DOE facilities that are likely to exhibit complex geochemical behavior as a result of intercontaminant reactions and/or microbiologic activity stimulated by organic substances. Use of the generic mixtures will focus research on important mixed contaminants that are likely to be long-term problems at DOE sites and that will require cleanup or remediation. The report provides information on the frequency of associations among different chemicals and compound classes at DOE waste sites that require remediation.

  11. PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH

    EPA Science Inventory

    A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

  12. (CHINA) PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH

    EPA Science Inventory

    A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

  13. Co-exposure with fullerene may strengthen health effects of organic industrial chemicals.

    PubMed

    Lehto, Maili; Karilainen, Topi; Róg, Tomasz; Cramariuc, Oana; Vanhala, Esa; Tornaeus, Jarkko; Taberman, Helena; Jänis, Janne; Alenius, Harri; Vattulainen, Ilpo; Laine, Olli

    2014-01-01

    In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene which can be used with fullerene as reagents or solvents in industrial processes. Potential co-exposure scenarios include a fullerene dust and organic chemical vapor, or a fullerene solution aerosolized in workplace air. Unfiltered and filtered mixtures of C60 and organic chemicals represent different co-exposure scenarios in in vitro studies where acute cytotoxicity and immunotoxicity of C60 and organic chemicals are tested together and alone by using human THP-1-derived macrophages. Statistically significant co-effects are observed for an unfiltered mixture of benzaldehyde and C60 that is more cytotoxic than benzaldehyde alone, and for a filtered mixture of m-cresol and C60 that is slightly less cytotoxic than m-cresol. Hydrophobicity of chemicals correlates with co-effects when secretion of pro-inflammatory cytokines IL-1β and TNF-α is considered. Complementary atomistic molecular dynamics simulations reveal that C60 co-aggregates with all chemicals in aqueous environment. Stable aggregates have a fullerene-rich core and a chemical-rich surface layer, and while essentially all C60 molecules aggregate together, a portion of organic molecules remains in water.

  14. Co-Exposure with Fullerene May Strengthen Health Effects of Organic Industrial Chemicals

    PubMed Central

    Róg, Tomasz; Cramariuc, Oana; Vanhala, Esa; Tornaeus, Jarkko; Taberman, Helena; Jänis, Janne; Alenius, Harri; Vattulainen, Ilpo; Laine, Olli

    2014-01-01

    In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene which can be used with fullerene as reagents or solvents in industrial processes. Potential co-exposure scenarios include a fullerene dust and organic chemical vapor, or a fullerene solution aerosolized in workplace air. Unfiltered and filtered mixtures of C60 and organic chemicals represent different co-exposure scenarios in in vitro studies where acute cytotoxicity and immunotoxicity of C60 and organic chemicals are tested together and alone by using human THP-1-derived macrophages. Statistically significant co-effects are observed for an unfiltered mixture of benzaldehyde and C60 that is more cytotoxic than benzaldehyde alone, and for a filtered mixture of m-cresol and C60 that is slightly less cytotoxic than m-cresol. Hydrophobicity of chemicals correlates with co-effects when secretion of pro-inflammatory cytokines IL-1β and TNF-α is considered. Complementary atomistic molecular dynamics simulations reveal that C60 co-aggregates with all chemicals in aqueous environment. Stable aggregates have a fullerene-rich core and a chemical-rich surface layer, and while essentially all C60 molecules aggregate together, a portion of organic molecules remains in water. PMID:25473947

  15. Pharmaceuticals and other organic chemicals in selected north-central and northwestern Arkansas streams

    USGS Publications Warehouse

    Haggard, B.E.; Galloway, J.M.; Green, W.R.; Meyer, M.T.

    2006-01-01

    Recently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemicals at 18 sites on seven selected streams in Arkansas, USA, during March, April, and August 2004. Water samples were collected upstream and downstream from the influence of effluent discharges in northwestern Arkansas and at one site on a relatively undeveloped stream in north-central Arkansas. At least one antibiotic, pharmaceutical, or other organic chemical was detected at all sites, except at Spavinaw Creek near Mayesville, Arkansas. The greatest number of detections was observed at Mud Creek downstream from an effluent discharge, including 31 pharmaceuticals and other organic chemicals. The detection of these chemicals occurred in higher frequency at sites downstream from effluent discharges compared to those sites upstream from effluent discharges; total chemical concentration was also greater downstream. Wastewater effluent discharge increased the concentrations of detergent metabolites, fire retardants, fragrances and flavors, and steroids in these streams. Antibiotics and associated degradation products were only found at two streams downstream from effluent discharges. Overall, 42 of the 108 chemicals targeted in this study were found in water samples from at least one site, and the most frequently detected organic chemicals included caffeine, phenol, para-cresol, and acetyl hexamethyl tetrahydro naphthalene (AHTN). ?? ASA, CSSA, SSSA.

  16. Research on lunar materials. [optical, chemical, and electrical properties

    NASA Technical Reports Server (NTRS)

    Gold, T.

    1978-01-01

    Abstracts of 14 research reports relating to investigations of lunar samples are presented. The principal topics covered include: (1) optical properties of surface and core samples; (2) chemical composition of the surface layers of lunar grains: Auger electron spectroscopy of lunar soil and ground rock samples; (3) high frequency electrical properties of lunar soil and rock samples and their relevance for the interpretation of lunar radar observations; (4) the electrostatic dust transport process; (5) secondary electron emission characteristics of lunar soil samples and their relevance to the dust transportation process; (6) grain size distribution in surface soil and core samples; and (7) the optical and chemical effects of simulated solar wind (2keV proton and a particle radiation) on lunar material.

  17. Historical cohort study of mortality among chemical researchers

    SciTech Connect

    Maher, K.V.; Defonso, L.R.

    1986-03-01

    This historical cohort study examined mortality among 1,510 white male researchers employed from 1950-1959 who handled chemicals. During 1950-1979, 95 deaths were observed, significantly less than the 173.2 predicted by general population rates (SMR = 55). This was due to deficits in overall cancer deaths (SMR = 66), particularly respiratory cancer (SMR = 28), and reduced mortality from circulatory diseases and accidents. Those who had worked directly with chemicals for more than 5 yr and those who had the most hazardous exposures experienced similar low mortality for all causes, all cancers, and respiratory cancer. Although deaths due to digestive cancer were elevated among those with 1-5 yr of work experience, there was no excess among those working more than 5 yr as would be expected from occupational exposure.

  18. Effects of organic solutes on chemical reactions of aluminum

    USGS Publications Warehouse

    Lind, Carol J.; Hem, John David

    1975-01-01

    Concentrations of organic matter in the general range of 1-10 milligrams per litre organic carbon are common in natural water, and many naturally occurrin7 organic compounds form aluminum complexes. The aluminum concentrations in near-neutral pH solutions may be 10-100 times higher than the values predicted from solubility data if formation of such organic complexes is ignored. The processes of polymerization of aluminum hydroxide and precipitation of gibbsite are inhibited by the presence of the organic flavone compound quercetin in concentrations as low as 10 x -5.3 mole per litre. Quercetin forms a complex, with a probable molar ratio of 1:2 aluminum to quercetin, that has a formation constant (f12) of about 10 12. A complex with a higher aluminum-quercetin ratio also was observed, but this material tends to evolve into a compound of low solubility that removes aluminum from solution. In the presence of both dissolved aluminum and aqueous silica, low concentrations of quercetin improved the yield of crystallized kaolinite and halloysite. Small amounts of well-shaped kaolinite and halloysite crystals were identified by electron microscopy in solutions with pH's in the range 6.5-8.5 after 155 days aging in one experimer t and 481 days aging in a repeated experiment. The bulk of the precipitated material was amorphous to X-rays, and crystalline material was too small a proportion of the total to give identifiable X-ray diffraction peaks. The precipitates had aluminum-silicon ratios near 1, and their solubility corresponded to that found by Hem, Roberson, Lind, and Polzer (1973) for similar aluminosilicate precipitated in the absence of organic solutes. The improved yield of crystalline material obtained in the presence of quercetin probably is the result of the influence of the organic compound on the aluminum hydroxide polymerization process. Natural water containing color imparted by organic material tends to be higher in aluminum than would be predicted by p

  19. Use of Fenton reagent to improve organic chemical biodegradability.

    PubMed

    Chamarro, E; Marco, A; Esplugas, S

    2001-03-01

    Fenton reagent has been used to test the degradation of different organic compounds (formic acid, phenol, 4-chlorophenol, 2,4-dichlorophenol and nitrobenzene) in aqueous solution. A stoichiometric coefficient for the Fenton reaction was found to be 0.5 mol of organic compound/mol of hydrogen peroxide, except for the formic acid where a value of approximately one was obtained (due to the direct formation of carbon dioxide). The treatment eliminates the toxic substances and increases the biodegradability of the treated water (measured as the ratio BOD5/COD). Biodegradability is attained when the initial compound is removed.

  20. Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: January-March 1999

    SciTech Connect

    Jubin, R.T.

    1999-11-01

    use in areas such as selective sorption, chemical sensing, and catalysis, as well as spectroscopic investigation into the fundamental interaction between ionic solvents and solutes in both low- and high-temperature ionic liquids. In the area of Separations and Materials Synthesis, fundamental studies explored the use of electromagnetic fields to enhance transport processes in multiphase separations; investigated nucleation and particle growth for the synthesis, characterization, application, and processing of ultrafine particles; and examined the use of electric fields to modify phase equilibria in multiphase separations processes. Other efforts involved enhanced oxidation of organic pollutants in aqueous solutions by applying electric fields to form microbubbles and the use of electric fields to improve distillation efficiency. Research was also directed toward the use of ozonation to treat water-soluble organics, the application of electrical and acoustic methods to remediate aerosol problems, and the development of improved means of decontamination using aqueous surfactant cleaners. Fluid Structure and Properties included molecular-based studies of systems with supercritical solvents, a multi-institutional initiative to develop a molecular understanding of reverse miscelles in supercritical carbon dioxide through experimentation and molecular simulation calculations, and molecular-based prediction of the structure and properties of long-chain molecules undergoing shear flow.

  1. Space research on organs and tissues

    NASA Technical Reports Server (NTRS)

    Tischler, Marc E.; Morey-Holton, Emily

    1993-01-01

    Studies in space on various physiological systems have and will continue to provide valuable information on how they adapt to reduced gravitational conditions, and how living in a 1 g (gravity) environment has guided their development. Muscle and bone are the most notable tissues that respond to unweighting caused by lack of gravity. The function of specific muscles and bones relates directly to mechanical loading, so that removal of 'normal forces' in space, or in bedridden patients, causes dramatic loss of tissue mass. The cardiovascular system is also markedly affected by reduced gravity. Adaptation includes decreased blood flow to the lower extremities, thus decreasing the heart output requirement. Return to 1 g is associated with a period of reconditioning due to the deconditioning that occurs in space. Changes in the cardiovascular system are also related to responses of the kidney and certain endocrine (hormone-producing) organs. Changes in respiratory function may also occur, suggesting an effect on the lungs, though this adaptation is poorly understood. The neurovestibular system, including the brain and organs of the inner ear, must adapt to the disorientation caused by lack of gravity. Preliminary findings have been reported for liver. Additionally, endocrine organs responsible for release of hormones such as insulin, growth hormone, glucocorticoids, and thyroid hormone may respond to spaceflight.

  2. Pesticide Chemical Research in Toxicology: Lessons from Nature.

    PubMed

    Casida, John E; Durkin, Kathleen A

    2017-01-17

    Pesticide researchers are students of nature, and each new compound and mechanism turns a page in the ever-expanding encyclopedia of life. Pesticides are both probes to learn about life processes and tools for pest management to facilitate food production and enhance health. In contrast to some household and industrial chemicals, pesticides are assumed to be hazardous to health and the environment until proven otherwise. About a thousand current pesticides working by more than 100 different mechanisms have helped understand many processes and coupled events. Pesticide chemical research is a major source of toxicology information on new natural products, novel targets or modes of action, resistance mechanisms, xenobiotic metabolism, selective toxicity, safety evaluations, and recommendations for safe and effective pest management. Target binding site models help define the effect of substituent changes and predict modifications for enhanced potency and safety and circumvention of resistance. The contribution of pesticide chemical research in toxicology is illustrated here with two each of the newer or most important insecticides, herbicides, and fungicides. The insecticides are imidacloprid and chlorantraniliprole acting on the nicotinic acetylcholine receptor and the ryanodine receptor Ca(2+) channel, respectively. The herbicides are glyphosate that inhibits aromatic amino acid biosynthesis and mesotrione that prevents plastoquinone and carotenoid formation. The fungicides are azoxystrobin inhibiting the Qo site of the cytochrome bc1 complex and prothioconazole inhibiting the 14α-demethylase in ergosterol biosynthesis. The two target sites involved for each type of pesticide account for 27-40% of worldwide sales for all insecticides, herbicides, and fungicides. In each case, selection for resistance involving a single amino acid change in the binding site or detoxifying enzyme circumvents the pesticide chemists's structure optimization and guarantees survival of

  3. Chemistry and the worm: Caenorhabditis elegans as a platform for integrating chemical and biological research.

    PubMed

    Hulme, S Elizabeth; Whitesides, George M

    2011-05-16

    This Review discusses the potential usefulness of the worm Caenorhabditis elegans as a model organism for chemists interested in studying living systems. C. elegans, a 1 mm long roundworm, is a popular model organism in almost all areas of modern biology. The worm has several features that make it attractive for biology: it is small (<1000 cells), transparent, and genetically tractable. Despite its simplicity, the worm exhibits complex phenotypes associated with multicellularity: the worm has differentiated cells and organs, it ages and has a well-defined lifespan, and it is capable of learning and remembering. This Review argues that the balance between simplicity and complexity in the worm will make it a useful tool in determining the relationship between molecular-scale phenomena and organism-level phenomena, such as aging, behavior, cognition, and disease. Following an introduction to worm biology, the Review provides examples of current research with C. elegans that is chemically relevant. It also describes tools-biological, chemical, and physical-that are available to researchers studying the worm.

  4. EVALUATION USING AN ORGANOPHILIC CLAY TO CHEMICALLY STABILIZE WASTE CONTAINING ORGANIC COMPOUNDS

    EPA Science Inventory

    A modified clay (organophilic) was utilized to evaluate the potential for chemically stabilizing a waste containing organic compounds. hemical bonding between the binder and the contaminants was indicated. eachate testing also indicated strong binding. Copy available at NTIS as ...

  5. Review of existing terrestrial bioaccumulation models and terrestrial bioaccumulation modeling needs for organic chemicals

    EPA Science Inventory

    Protocols for terrestrial bioaccumulation assessments are far less-developed than for aquatic systems. This manuscript reviews modeling approaches that can be used to assess the terrestrial bioaccumulation potential of commercial organic chemicals. Models exist for plant, inver...

  6. PREDICTION OF CHEMICAL RESIDUES IN AQUATIC ORGANISMS FOR A FIELD DISCHARGE SITUATION.

    EPA Science Inventory

    A field study was performed which compared predicted and measured concentrations of chemicals in receiving water organisms from three sampling locations on Five Mile Creek, Birmingham, Al. Two point source discharges, both from coke manufacturing facilities, were included in the ...

  7. ESTIMATION OF PHYSICAL PROPERTIES AND CHEMICAL REACTIVITY PARAMETERS OF ORGANIC COMPOUNDS

    EPA Science Inventory

    The computer program SPARC (Sparc Performs Automated Reasoning in Chemistry)has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms ...

  8. PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC

    EPA Science Inventory

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  9. Real World of Industrial Chemistry: Ethylene: The Organic Chemical Industry's Most Important Building Block.

    ERIC Educational Resources Information Center

    Fernelius, W. Conrad, Ed.; And Others

    1979-01-01

    The value of ethylene, as the organic chemical industry's most important building block, is discussed. The discussion focuses on the source of ethylene, its various forms and functions, and the ways in which the forms are made. (SA)

  10. Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

    ERIC Educational Resources Information Center

    Kolb, Kenneth E.; Kolb, Doris

    1983-01-01

    Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

  11. Abiotic reduction reactions of anthropogenic organic chemicals in anaerobic systems: A critical review

    NASA Astrophysics Data System (ADS)

    Macalady, Donald L.; Tratnyek, Paul G.; Grundl, Timothy J.

    1986-02-01

    This review is predicated upon the need for a detailed process-level understanding of factors influencing the reduction of anthropogenic organic chemicals in natural aquatic systems. In particular, abiotic reductions of anthropogenic organic chemicals are reviewed. The most important reductive reaction is alkyl dehalogenation (replacement of chloride with hydrogen) which occurs in organisms, sediments, sewage sludge, and reduced iron porphyrin model systems. An abiotic mechanism involving a free radical intermediate has been proposed. The abstraction of vicinal dihalides (also termed dehalogenation) is another reduction that may have an abiotic component in natural systems. Reductive dehalogenation of aryl halides has recently been reported and further study of this reaction is needed. Several other degradation reactions of organohalides that occur in anaerobic environments are mentioned, the most important of which is dehydrohalogenation. The reduction of nitro groups to amines has also been thoroughly studied. The reactions can occur abiotically, and are affected by the redox conditions of the experimental system. However, a relationship between nitro-reduction rate and measured redox potential has not been clearly established. Reductive dealkylation of the N- and O-heteroatom of hydrocarbon pollutants has been observed but not investigated in detail. Azo compounds can be reduced to their hydrazo derivatives and a thorough study of this reaction indicates that it can be caused by extracellular electron transfer agents. Quinone-hydroquinone couples are important reactive groups in humic materials and similar structures in resazurin and indigo carmine make them useful as models for environmental redox conditions. The interconversion of sulfones, sulfoxides, and sulfides is a redox process and is implicated in the degradation of several pesticides though the reactions need more study. Two reductive heterocyclic cleavage reactions are also mentioned. Finally, several

  12. International energy: Research organizations, 1988--1992. Revision 1

    SciTech Connect

    Hendricks, P.; Jordan, S.

    1993-06-01

    This publication contains the standardized names of energy research organizations used in energy information databases. Involved in this cooperative task are (1) the technical staff of the US DOE Office of Scientific and Technical Information (OSTI) in cooperation with the member countries of the Energy Technology Data Exchange (ETDE) and (2) the International Nuclear Information System (INIS). ETDE member countries are also members of the International Nuclear Information System (INIS). Nuclear organization names recorded for INIS by these ETDE member countries are also included in the ETDE Energy Database. Therefore, these organization names are cooperatively standardized for use in both information systems. This publication identifies current organizations doing research in all energy fields, standardizes the format for recording these organization names in bibliographic citations, assigns a numeric code to facilitate data entry, and identifies report number prefixes assigned by these organizations. These research organization names may be used in searching the databases ``Energy Science & Technology`` on DIALOG and ``Energy`` on STN International. These organization names are also used in USDOE databases on the Integrated Technical Information System. Research organizations active in the past five years, as indicated by database records, were identified to form this publication. This directory includes approximately 31,000 organizations that reported energy-related literature from 1988 to 1992 and updates the DOE Energy Data Base: Corporate Author Entries.

  13. Heteroepitaxial growth of 3-5 semiconductor compounds by metal-organic chemical vapor deposition for device applications

    NASA Technical Reports Server (NTRS)

    Collis, Ward J.; Abul-Fadl, Ali

    1988-01-01

    The purpose of this research is to design, install and operate a metal-organic chemical vapor deposition system which is to be used for the epitaxial growth of 3-5 semiconductor binary compounds, and ternary and quaternary alloys. The long-term goal is to utilize this vapor phase deposition in conjunction with existing current controlled liquid phase epitaxy facilities to perform hybrid growth sequences for fabricating integrated optoelectronic devices.

  14. MODELING MULTICOMPONENT ORGANIC CHEMICAL TRANSPORT IN THREE FLUID PHASE POROUS MEDIA

    EPA Science Inventory

    A two-dimensional finite-element model was developed to predict coupled transient flow and multicomponent transport of organic chemicals which can partition between nonaqueous phase liquid, water, gas and solid phases in porous media under the assumption of local chemical equilib...

  15. REVIEW OF VOLATILE ORGANIC COMPOUND SOURCE APPORTIONMENT BY CHEMICAL MASS BALANCE. (R826237)

    EPA Science Inventory

    The chemical mass balance (CMB) receptor model has apportioned volatile organic compounds (VOCs) in more than 20 urban areas, mostly in the United States. These applications differ in terms of the total fraction apportioned, the calculation method, the chemical compounds used ...

  16. Solid-state NMR analysis of soil organic matter fractions from integrated physical-chemical extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fractions of soil organic matter (SOM) are usually extracted from soil by either physical (size, density) or chemical (e.g., base, acid) procedures. In this study we used 13C nuclear magnetic resonance (NMR) spectroscopy to chemically characterize the fractions that were obtained by an integrated pr...

  17. CTEPP-OH DATA ANALYTICAL RESULTS ORGANIZED BY CHEMICAL AND MEDIA

    EPA Science Inventory

    This data set contains the field sample data by chemical and matrix for CTEPP-OH. The data is organized at the sample, chemical level.

    The Children’s Total Exposure to Persistent Pesticides and Other Persistent Pollutant (CTEPP) study was one of the largest aggregate exposure ...

  18. The 2010 Rankings of Chemical Education and Science Education Journals by Faculty Engaged in Chemical Education Research

    ERIC Educational Resources Information Center

    Towns, Marcy H.; Kraft, Adam

    2012-01-01

    Faculty active in chemical education research from around the world ranked 22 journals publishing research in chemical education and science education. The results of this survey can be used to supplement impact factors that are often used to compare the quality of journals in a field. Knowing which journals those in the field rank as top tier is…

  19. Surface phenomena with organic coatings for chemical sensing

    NASA Astrophysics Data System (ADS)

    Greibl, Wolfgang; Hayden, Oliver; Achatz, Paul; Fischerauer, G.; Scholl, G.; Dickert, Franz L.

    2002-02-01

    The surface modification of SAW (surface acoustic wave)- and QCM (quartz crystal microbalance)-devices proves very important in chemical sensing. Silanes on one hand are very useful for hydrophobizing of quartz-surfaces whereas on the other hand thiols are used to adsorb on gold. In this way the influence of humidity on the transducers, which originates in the hydrophilicity of the quartz is decreased. These monolayers not only reduce the cross-sensitivity to water but also enhance the sensor effects of solvent vapors. In order to obtain better selectivity molecular hollows, like calix[n]arenes can be attached to the spacers. Another way to improve the selectivity was found in the treatment of the device with mixtures of silanes and thiols, respectively. In this way cavities are produced in which analytes are incorporated and thus are detected in the lower ppm range. The surface of mass-sensitive devices was also modified in order to detect analytes in the nano- to micrometer range. Here a stamping process with cells yields patterns on polymer surfaces which favor the reinclusion of these microorganisms. These effects are due to geometrical effects and chemical interactions via an adapted polarity and hydrogen bonds of the chosen polymer. The sensor responses proved highly selective to the bacteria in respect to nutrient liquid and other microorganisms.

  20. Mechanical-chemical analyses and sub-chronic systemic toxicity of chemical treated organic bovine bone.

    PubMed

    Lee, Kwang-il; Lee, Jung-soo; Lee, Keun-soo; Jung, Hong-hee; Ahn, Chan-min; Kim, Young-sik; Shim, Young-bock; Jang, Ju-woong

    2015-12-01

    Sequentially chemical-treated bovine bone was not only evaluated by mechanical and chemical analyses but also implanted into the gluteal muscles of rats for 12 weeks to investigate potential local pathological effects and systemic toxicities. The test (chemical treated bone) and control (heat treated bone) materials were compared using scanning electron microscope (SEM), x-ray diffraction pattern, inductively coupled plasma analysis, and bending strength test. In the SEM images, the micro-porous structure of heat-treated bone was changed to sintered ceramic-like structure. The structure of bone mineral from test and control materials was analyzed as100% hydroxyapatite. The ratio of calcium (Ca) to potassium (P), the main inorganic elements, was same even though the Ca and P percentages of the control material was relatively higher than the test material. No death or critical symptoms arose from implantation of the test (chemical treated bone) and control (physiological saline) materials during 12 weeks. The implanted sites were macroscopically examined, with all the groups showing non-irritant results. Our results indicate that chemical processed bovine bone has a better mechanical property than the heat treated bone and the implantation of this material does not produce systemic or pathological toxicity.

  1. Space chemical propulsion test facilities at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Urasek, Donald C.; Calfo, Frederick D.

    1993-01-01

    The NASA Lewis Research Center, located in Cleveland, Ohio has a number of space chemical propulsion test facilities which constitute a significant national space testing resource. The purpose of this paper is to make more users aware of these test facilities and to encourage their use through cooperative agreements between the government, industry, and universities. Research which is of interest to the government is especiallly encouraged and often can be done in a cooperative manner that best uses the resources of all parties. This paper presents an overview of the Lewis test facilities. These facilities are clustered into three test areas: the Rocket Engine Test Facilities (RETF), the Rocket Laboratory (RL), and the Cryogenic Components Laboratory (CCL).

  2. Organic chemicals jeopardize the health of freshwater ecosystems on the continental scale

    PubMed Central

    Malaj, Egina; von der Ohe, Peter C.; Grote, Matthias; Kühne, Ralph; Mondy, Cédric P.; Usseglio-Polatera, Philippe; Brack, Werner; Schäfer, Ralf B.

    2014-01-01

    Organic chemicals can contribute to local and regional losses of freshwater biodiversity and ecosystem services. However, their overall relevance regarding larger spatial scales remains unknown. Here, we present, to our knowledge, the first risk assessment of organic chemicals on the continental scale comprising 4,000 European monitoring sites. Organic chemicals were likely to exert acute lethal and chronic long-term effects on sensitive fish, invertebrate, or algae species in 14% and 42% of the sites, respectively. Of the 223 chemicals monitored, pesticides, tributyltin, polycyclic aromatic hydrocarbons, and brominated flame retardants were the major contributors to the chemical risk. Their presence was related to agricultural and urban areas in the upstream catchment. The risk of potential acute lethal and chronic long-term effects increased with the number of ecotoxicologically relevant chemicals analyzed at each site. As most monitoring programs considered in this study only included a subset of these chemicals, our assessment likely underestimates the actual risk. Increasing chemical risk was associated with deterioration in the quality status of fish and invertebrate communities. Our results clearly indicate that chemical pollution is a large-scale environmental problem and requires far-reaching, holistic mitigation measures to preserve and restore ecosystem health. PMID:24979762

  3. Organic chemicals jeopardize the health of freshwater ecosystems on the continental scale.

    PubMed

    Malaj, Egina; von der Ohe, Peter C; Grote, Matthias; Kühne, Ralph; Mondy, Cédric P; Usseglio-Polatera, Philippe; Brack, Werner; Schäfer, Ralf B

    2014-07-01

    Organic chemicals can contribute to local and regional losses of freshwater biodiversity and ecosystem services. However, their overall relevance regarding larger spatial scales remains unknown. Here, we present, to our knowledge, the first risk assessment of organic chemicals on the continental scale comprising 4,000 European monitoring sites. Organic chemicals were likely to exert acute lethal and chronic long-term effects on sensitive fish, invertebrate, or algae species in 14% and 42% of the sites, respectively. Of the 223 chemicals monitored, pesticides, tributyltin, polycyclic aromatic hydrocarbons, and brominated flame retardants were the major contributors to the chemical risk. Their presence was related to agricultural and urban areas in the upstream catchment. The risk of potential acute lethal and chronic long-term effects increased with the number of ecotoxicologically relevant chemicals analyzed at each site. As most monitoring programs considered in this study only included a subset of these chemicals, our assessment likely underestimates the actual risk. Increasing chemical risk was associated with deterioration in the quality status of fish and invertebrate communities. Our results clearly indicate that chemical pollution is a large-scale environmental problem and requires far-reaching, holistic mitigation measures to preserve and restore ecosystem health.

  4. Visualising the equilibrium distribution and mobility of organic contaminants in soil using the chemical partitioning space.

    PubMed

    Wong, Fiona; Wania, Frank

    2011-06-01

    Assessing the behaviour of organic chemicals in soil is a complex task as it is governed by the physical chemical properties of the chemicals, the characteristics of the soil as well as the ambient conditions of the environment. The chemical partitioning space, defined by the air-water partition coefficient (K(AW)) and the soil organic carbon-water partition coefficient (K(OC)), was employed to visualize the equilibrium distribution of organic contaminants between the air-filled pores, the pore water and the solid phases of the bulk soil and the relative importance of the three transport processes removing contaminants from soil (evaporation, leaching and particle erosion). The partitioning properties of twenty neutral organic chemicals (i.e. herbicides, pharmaceuticals, polychlorinated biphenyls and volatile chemicals) were estimated using poly-parameter linear free energy relationships and superimposed onto these maps. This allows instantaneous estimation of the equilibrium phase distribution and mobility of neutral organic chemicals in soil. Although there is a link between the major phase and the dominant transport process, such that chemicals found in air-filled pore space are subject to evaporation, those in water-filled pore space undergo leaching and those in the sorbed phase are associated with particle erosion, the partitioning coefficient thresholds for distribution and mobility can often deviate by many orders of magnitude. In particular, even a small fraction of chemical in pore water or pore air allows for evaporation and leaching to dominate over solid phase transport. Multiple maps that represent soils that differ in the amount and type of soil organic matter, water saturation, temperature, depth of surface soil horizon, and mineral matters were evaluated.

  5. The destruction of halogenated organic chemicals by plasma pyrolysis.

    PubMed

    Barton, T G; Mordy, J A

    1984-08-01

    Very high destruction efficiencies for halogenated chemicals have been achieved by plasma pyrolysis. Destruction efficiencies exceeded 99.9999999% for tests with polychlorinated biphenyls (PCBs). Preliminary tests with tetrachloromethane have obtained destruction efficiencies exceeding 99.99%. The plasma pyrolysis process involved the creation of a 250-kW plasma with a temperature in excess of 25 000 degrees C. The toxic material was injected into the plasma zone at a rate between 1 and 2 L/min. Thermochemical and photochemical dissociation of the toxic materials produced atoms and ions which recombined to form primarily H2, CO, HCl, and particulate carbon. The HCl was neutralized by NaOH. The flaring of the H2 and CO should destroy to a high degree any trace residuals. The application of plasma pyrolysis for the ultimate disposal of toxicological waste was also investigated. Rat carcasses containing mean lethal dosage of PCB were pyrolyzed.

  6. Chemical transformations during ambient air sampling for organic vapors

    SciTech Connect

    Pellizzari, E.D.; Drost, K.J.

    1984-09-01

    Potential chemical transformations of olefins in the presence of ozone and high levels (ppm) of halogens (Cl/sub 2/, Br/sub 2/) were demonstrated when sampling ambient air with a sorbent cartridge. The use of stryene-d/sub 8/ and cyclohexene-d/sub 10/ spiked sampling devices and capillary gas chromatography/mass spectrometry (GC/MS) analysis allowed the detection and identification of several deuteriated oxidation and halogenated products. Dimethylamine-d/sub 6/ was converted in trace quantities (5-10 mg) to dimethylnitrosamine-d/sub 6/ when sampling was conducted in the presence of NO/sub x/. Oxidation reactions were prevented when filters (2.5 cm) employed for removing particulates were impregnated with 5-10 mg of sodium thiosulfate and placed in front of the sorbent cartridge. Halogenation reactions were also consideraly reduced.

  7. Catalyst accessibility to chemical reductants in metal-organic frameworks.

    PubMed

    Roy, Souvik; Pascanu, Vlad; Pullen, Sonja; González Miera, Greco; Martín-Matute, Belén; Ott, Sascha

    2017-03-18

    A molecular H2-evolving catalyst, [Fe2(cbdt)(CO)6] ([FeFe], cbdt = 3-carboxybenzene-1,2-dithiolate), has been attached covalently to an amino-functionalized MIL-101(Cr) through an amide bond. Chemical reduction experiments reveal that the MOF channels can be clogged by ion pairs that are formed between the oxidized reductant and the reduced catalyst. This effect is lessened in MIL-101-NH-[FeFe] with lower [FeFe] loadings. On longer timescales, it is shown that large proportions of the [FeFe] catalysts within the MOF engage in photochemical hydrogen production and the amount of produced hydrogen is proportional to the catalyst loading.

  8. Accelerated Chemical Reactions and Organic Synthesis in Leidenfrost Droplets.

    PubMed

    Bain, Ryan M; Pulliam, Christopher J; Thery, Fabien; Cooks, R Graham

    2016-08-22

    Leidenfrost levitated droplets can be used to accelerate chemical reactions in processes that appear similar to reaction acceleration in charged microdroplets produced by electrospray ionization. Reaction acceleration in Leidenfrost droplets is demonstrated for a base-catalyzed Claisen-Schmidt condensation, hydrazone formation from precharged and neutral ketones, and for the Katritzky pyrylium into pyridinium conversion under various reaction conditions. Comparisons with bulk reactions gave intermediate acceleration factors (2-50). By keeping the volume of the Leidenfrost droplets constant, it was shown that interfacial effects contribute to acceleration; this was confirmed by decreased reaction rates in the presence of a surfactant. The ability to multiplex Leidenfrost microreactors, to extract product into an immiscible solvent during reaction, and to use Leidenfrost droplets as reaction vessels to synthesize milligram quantities of product is also demonstrated.

  9. Prediction of ecotoxicological behavior of chemicals: relationship between n-octanol/water partition coefficient and bioaccumulation of organic chemicals by alga Chlorella

    SciTech Connect

    Geyer, H.; Politzki, G.; Freitag, D.

    1984-01-01

    The bioaccumulation potential of organic chemicals by the green alga Chlorella fusca was determined. A quantitative relationship was found to exist between the lipophilicity (n-octanol/water partition coefficient) of the chemicals and the bioaccumulation factor.

  10. Use of the Chemical Transformation Simulator as a Parameterization Tool for Modeling the Environmental Fate of Organic Chemicals and their Transformation Products

    EPA Science Inventory

    A Chemical Transformation Simulator is a web-based system for predicting transformation pathways and physicochemical properties of organic chemicals. Role in Environmental Modeling • Screening tool for identifying likely transformation products in the environment • Parameteri...

  11. Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division, April--June 1997

    SciTech Connect

    Jubin, R.T.

    1998-06-01

    The Chemical and Energy Research Section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within six major areas of research: Hot Cell Operations, Process Chemistry and thermodynamics, Separations and Materials Synthesis, Solution Thermodynamics, biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information.

  12. Research Mediation in Education: A Typology of Research Brokering Organizations that Exist across Canada

    ERIC Educational Resources Information Center

    Cooper, Amanda Mae

    2013-01-01

    This paper explores the increasingly prominent role of research brokering organizations (RBOs) in strengthening connections between education research, policy and practice across Canada. This paper is organized in three sections. First, it provides a literature review of research mediation--exploring terminology, models and empirical work (albeit…

  13. Identifying new persistent and bioaccumulative organics among chemicals in commerce. III: byproducts, impurities, and transformation products.

    PubMed

    Howard, Philip H; Muir, Derek C G

    2013-05-21

    The goal of this series of studies was to identify commercial chemicals that might be persistent and bioaccumulative (PB) and that were not being considered in current wastewater and aquatic environmental measurement programs. In this study, we focus on chemicals that are not on commercial chemical lists such as U.S. EPA's Inventory Update Rule but may be found as byproducts or impurities in commercial chemicals or are likely transformation products from commercial chemical use. We evaluated the 610 chemicals from our earlier publication as well as high production volume chemicals and identified 320 chemicals (39 byproducts and impurities, and 281 transformation products) that could be potential PB chemicals. Four examples are discussed in detail; these chemicals had a fair amount of information on the commercial synthesis and byproducts and impurities that might be found in the commercial product. Unfortunately for many of the 610 chemicals, as well as the transformation products, little or no information was available. Use of computer-aided software to predict the transformation pathways in combination with the biodegradation rules of thumb and some basic organic chemistry has allowed 281 potential PB transformation products to be suggested for some of the 610 commercial chemicals; more PB transformation products were not selected since microbial degradation often results in less persistent and less bioaccumulative metabolites.

  14. PHYSICOCHEMICAL PROPERTIES AS PREDICTORS OF ORGANIC CHEMICAL EFFECTS ON SOIL MICROBIAL RESPIRATION

    EPA Science Inventory

    Structure-activity analysis was used to evaluate the effects of 19 hazardous organic chemicals on microbial respiration in two slightly acidic soils (a Captina silt loam from Roane County Tennessee, and a McLaurin sandy loam from Stone County, Mississippi), both low in organic ca...

  15. Organic fouling and chemical cleaning of nanofiltration membranes: measurements and mechanisms.

    PubMed

    Li, Qilin; Elimelech, Menachem

    2004-09-01

    Fouling and subsequent chemical cleaning of nanofiltration (NF) membranes used in water quality control applications are often inevitable. To unravel the mechanisms of organic fouling and chemical cleaning, it is critical to understand the foulant-membrane, foulant-foulant, and foulant-cleaning agent interactions at the molecular level. In this study, the adhesion forces between the foulant and the membrane surface and between the bulk foulant and the fouling layer were determined by atomic force microscopy (AFM). A carboxylate modified AFM colloid probe was used as a surrogate for humic acid, the major organic foulant in natural waters. The interfacial force data were combined with the NF membrane water flux measurements to elucidate the mechanisms of organic fouling and chemical cleaning. A remarkable correlation was obtained between the measured adhesion forces and the fouling and cleaning behavior of the membrane under various solution chemistries. The AFM measurements further confirmed that divalent calcium ions greatly enhance natural organic matter fouling by complexation and subsequent formation of intermolecular bridges among organic foulant molecules. Efficient chemical cleaning was achieved only when the calcium ion bridging was eliminated as a result of the interaction between the chemical cleaning agent and the fouling layer. The cleaning efficiency was highly dependent on solution pH and the concentration of the chemical cleaning agent.

  16. Modeling organic chemical fate in aquatic systems: Significance of bioaccumulation and relevant time-space scales

    SciTech Connect

    Thomann, R.V.

    1995-06-01

    The importance of aquatic food chain bioaccumulation of organic chemicals in contributing to human dose is derived. It is shown that for chemicals with log octanol water partition coefficients greater than about 3, the role of food chain transfer to fish consumed by humans becomes the more dominant route over drinking water. Modeling of aquatic food chain bioaccumulation then becomes necessary to accurately estimate dose of such chemicals to humans. The relevant time and space scales for groundwater and surface water also indicate a division of organic chemicals at a log octanol water partition coefficient of about 3. For chemicals greater than that level, groundwater transport is minimal, while for chemicals with log octanol water coefficients of less than about 3, detention times are long relative to surface water and biodegradation processes become more significant. An illustration is given of modeling the groundwater transport of two organic chemicals (BCEE and benzene) and a metal (chromium) at a Superfund site. The model indicates that after 10 years only a relatively small fraction of the chemicals had traveled in the groundwater about 300 m to the point of release from the site to surface water. On the other hand, steady state in the adjacent stream and lake is reached rapidly over a distance of 2000 m, illustrating the difference in spatial and temporal scales for the groundwater and surface water. 15 refs., 8 figs., 1 tab.

  17. Person-Organization Fit and Research on Instruction

    ERIC Educational Resources Information Center

    Youngs, Peter; Pogodzinski, Ben; Grogan, Erin; Perrone, Frank

    2015-01-01

    Research from industrial and organizational (I-O) psychology indicates that outside of K-12 education, employees' sense of fit with their organizations is often associated with job satisfaction, performance, commitment, and retention. Person-organization (P-O) fit has been conceptualized as the degree of congruence between an…

  18. Assessing mobility of household organic hazardous chemicals in landfill

    SciTech Connect

    Xie, R.; Zeiss, C.

    1995-11-01

    The principal components of these hazardous materials are motor oils, detergents, paints and pesticides. Occurrence of their ingredients in landfill leachate follows source release function that determines their discharge rate to groundwater. Five compounds were identified very mobile in the landfill based on mobility index calculations. They were phenolate for the motor oil group, ethylene oxide and thylene glycol from detergent group, and formaldehyde and methylethyl ketone (MEK) from the paint group. These five chemicals were used as tracing compounds for quantitative assessment of their emission to the groundwater. An analytical solution to a one dimensional convective-diffusion transport equation was used to model their transport in the landfill. The model into which the channeled flow was incorporated considered adsorption-desorption and degradation. Leachate from earlier stage of leaching had significantly higher concentrations of the tracing compounds in comparison to that produced later. Contaminant concentrations in leachate decreased with time and the decreases occurred in order of formaldehyde {ge} phenol > MEK {ge} ethylene glycol > ethylene oxide. Concentrations of phenol, formaldehyde, and ethylene glycol were less than 0.02 g/L, which is about 0.1% of initial concentration, after 11 weeks. It took 22 weeks for MEK to be reduced to the same concentration at a velocity of 6 pore volumes per year.

  19. Complex organic chemical balms of Pharaonic animal mummies.

    PubMed

    Buckley, Stephen A; Clark, Katherine A; Evershed, Richard P

    2004-09-16

    Millions of votive mummies of mammals, birds and reptiles were produced throughout ancient Egypt, with their popularity increasing during the reign of Amenhotep III (1400 bc) and thereafter. The scale of production has been taken to indicate that relatively little care and expense was involved in their preparation compared with human mummies. The accepted view is that animals were merely wrapped in coarse linen bandages and/or dipped in 'resin' before death. However, as with human mummification there was a range of qualities of treatments, and visual inspection of animal mummies suggests that the procedures used were often as complex as those used in humans (for example, evisceration and elaborate bandaging). Moreover, the ancient Egyptians treated animals with great respect, regarding them both as domestic pets and representatives of the gods; for example, the cat symbolized the goddess Bastet; the hawk, Horus; the ibis, Thoth, and so on. We report here the results of chemical investigations of tissues and wrappings from Pharaonic cat, hawk and ibis mummies using gas chromatography, gas chromatography-mass spectrometry, thermal desorption-gas chromatography-mass spectrometry and pyrolysis-gas chromatography-mass spectrometry. The analyses reveal the presence of highly complex mixtures of n-alkyl and cyclic biomarker components characteristic of fats, oils, beeswax, sugar gum, petroleum bitumen, and coniferous, Pistacia and possibly cedar resins. The mixture of balms is of comparable complexity to those used to mummify humans from the same period.

  20. Chemical equilibrium of minced turkey meat in organic acid solutions.

    PubMed

    Goli, T; Abi Nakhoul, P; Zakhia-Rozis, N; Trystram, G; Bohuon, P

    2007-02-01

    The distribution of acid (HA), anions (A(-)), free protons (H(3)O(+)) and bound protons (H(b)), in homogenized turkey meat was evaluated at various meat/water mass ratios of (1/4-1/10) during titration with acetic acid (0.25N) or lactic acid (0.2N). H(b) concentration was determined by titration with hydrochloric acid (0.075N) and a correlation for [H(b)]=f(pH) was proposed. A procedure was used to calculate the fractions of the various species in equilibrium, starting from an initial acid concentration in a meat/water system and assuming the accuracy of the pK(a) value of the pure weak acids despite the chemical complexity of meat. Calculated results were in very good agreement (±0.15) with experimental pH values, whatever the acid, meat batch or meat/water mass ratios used. Less than 1% of the total protons were free (H(3)O(+)) and determined the meat pH.

  1. Rapid destruction of organic chemicals in groundwater using sunlight

    SciTech Connect

    Tyner, C.E.; Haslund, C.A.; Pacheco, J.E.; Holmes, J.T.

    1989-01-01

    We are currently investigating a solar-driven photocatalytic process that promises to destroy low concentrations of hazardous organic molecules in large volumes of contaminated groundwater or industrial waste streams. Preliminary results of laboratory-scale screening tests using a model compound, salicylic acid, and titanium dioxide catalyst have shown that no measurable reaction occurs without both uv light and catalyst; no measurable volatilization of the salicylic acid occurs at room temperature; salicylic acid destruction rates depend on catalyst supplier and concentration and on uv light intensity; and some intermediates are being formed and subsequently destroyed. Observed reaction rates are consistent with those observed in an initial pilot-scale solar test of a falling-film reactor, although further testing will be required to quantify the comparison. 10 refs., 5 figs.

  2. Self-organization of disc-like molecules: chemical aspects.

    PubMed

    Kumar, Sandeep

    2006-01-01

    The hierarchical self-assembly of disc-shaped molecules leads to the formation of discotic liquid crystals. These materials are of fundamental importance not only as models for the study of energy and charge migration in self-organized systems but also as functional materials for device applications such as, one-dimensional conductors, photoconductors, light emitting diodes, photovoltaic solar cells, field-effect transistors and gas sensors. The negative birefringence films formed by polymerized nematic discotic liquid crystals have been commercialized as compensation foils to enlarge the viewing angle of commonly used twisted nematic liquid crystal displays. To date the number of discotic liquid crystals derived from more than 50 different cores comes to about 3000. This critical review describes, after an in-depth introduction, recent advances in basic design principles and synthetic approaches towards the preparation of most frequently encountered discotic liquid crystals.

  3. Microbial metabolism fuels ecosystem-scale organic matter transformations: an integrated biological and chemical perspective

    NASA Astrophysics Data System (ADS)

    Wrighton, K. C.; Narrowe, A. B.; Angle, J.; Stefanik, K. S.; Daly, R. A.; Johnston, M.; Miller, C. S.

    2014-12-01

    Freshwater saturated sediments and soils represent vital ecosystems due to their nutrient cycling capacities and their prominent contribution to global greenhouse gas emissions. However, the diversity of microorganisms and metabolic pathways involved in carbon cycling, and the impacts of these processes on other biogeochemical cycles remain poorly understood. Major advances in DNA sequencing have helped forge linkages between the previously disconnected biological and chemical components of these systems. Here, we present data on the use of assembly-based metagenomics to generate hypotheses on microbial carbon degradation and biogeochemical cycling in waterlogged sediments and soils. DNA sequencing from a fresh water aquifer adjacent to the Colorado River in Rifle, CO yielded extensive genome recovery from multiple previously unknown bacterial lineages. Fermentative metabolisms encoded by these genomes drive nitrogen, hydrogen, and sulfur cycling in this subsurface system. We are also applying a similar approach to identify microbial processes in a freshwater wetland on Lake Erie, OH. Given the increased diversity (increased richness, decreased evenness, and strain variation) of wetland sediment microbial communities, we modified methods for specialized assembly of long taxonomic marker gene amplicons (EMIRGE) to create a biogeographical map of Fungi, Archaea, and Bacteria along depth and hydrological transects. This map reveals that the microbial community associated with the top two depths (>7 cm) is significantly different from bottom depths (7-40 cm). Dissolved organic matter (DOM) molecular weight and the presence of oxidized terminal electron acceptors best predict differences in microbial community structure. Laboratory mesocosms amended with pore-water DOM, in situ soil communities, and variable oxygen conditions link DOM composition and redox to microbial metabolic networks, biogeochemical cycles, and green house gas emission. Organism identities from

  4. Modeling the elution of organic chemicals from a melting homogeneous snow pack.

    PubMed

    Meyer, Torsten; Wania, Frank

    2011-06-01

    Organic chemicals are often released in peak concentrations from melting snow packs. A simple, mechanistic snowmelt model was developed to simulate and predict the elution of organic substances from melting, homogeneous snow, as influenced by chemical properties and snow pack characteristics. The model calculates stepwise the chemical transport along with the melt water flow in a multi-layered snow pack, based on chemical equilibrium partitioning between the individual bulk snow phases. The model succeeds in reproducing the elution behavior of several organic contaminants observed in previously conducted cold room experiments. The model aided in identifying four different types of enrichment of organic substances during snowmelt. Water soluble substances experience peak releases early during a melt period (type 1), whereas chemicals that strongly sorb to particulate matter (PM) or snow grain surfaces elute at the end of melting (type 2). Substances that are somewhat water soluble and at the same time have a high affinity for snow grain surfaces may exhibit increasing concentrations in the melt water (type 3). Finally, elution sequences involving peak loads both at the beginning and the end of melting are simulated for chemicals that are partially dissolved in the aqueous melt water phase and partially sorbed to PM (type 4). The extent of type 1 enrichment mainly depends on the snow depth, whereby deeper snow generates more pronounced concentration peaks. PM influences the elution behavior of organic chemicals strongly because of the very large natural variability in the type and amount of particles present in snow. Urban and road-side snow rich in PM can generate type 2 concentration peaks at the end of the melt period for even relatively water soluble substances. From a clean, melting snow pack typical for remote regions, even fairly hydrophobic chemicals can be released in type 1 mode while being almost completely dissolved in the aqueous melt water phase. The

  5. Estimating the toxicities of organic chemicals to bioluminescent bacteria and activated sludge.

    PubMed

    Ren, Shijin; Frymier, Paul D

    2002-10-01

    Toxicity assays based on bioluminescent bacteria have several advantages including a quick response and an easily measured signal. The Shk1 assay is a procedure for wastewater toxicity testing based on the bioluminescent bacterium Shk1. Using the Shk1 assay, the toxicity of 98 organic chemicals were measured and EC50 values were obtained. Quantitative structure-activity relationship (QSAR) models based on the logarithm of the octanol-water partition coefficient (log(Kow)) were developed for individual groups of organic chemicals with different functional groups. The correlation coefficients for different groups of organic compounds varied between 0.69 and 0.99. An overall QSAR model without discriminating the functional groups, which can be used for a quick estimate of the toxicities of organic chemicals, was also developed and model predictions were compared to experimental data. The model accuracy was found to be one order of magnitude from the observed values.

  6. Chemically selective coated quartz-crystal-microbalance (QCM) array for detection of volatile organic chemicals

    NASA Astrophysics Data System (ADS)

    Schneider, Thomas W.; Frye-Mason, Gregory C.; Martin, Stephen J.; Spates, James J.; Bohuszewicz, Teresa V.; Osbourn, Gordon C.; Bartholomew, John W.

    1998-12-01

    Liquid flow cells have been fabricated to prepare an array of QCMs operating simultaneously for detection and identification of VOCs in water. Two signals, a frequency response and a damping voltage response, were obtained per resonator. A blank QCM was used as a reference to account for changes in liquid density and viscosity. Nine different polymer coatings applied using a spin coat technique have been examined for VOC response under liquid flow conditions. A matrix of three classes of VOCs were examined for each coating with four chemicals in each class. The three classes of VOCs are polar, nonpolar and chlorinated. A pattern recognition technique, called visually empirical region of influence, was used to cluster the responses in n- dimensional space. Chemicals within a class varying by only one methyl group (e.g., toluene and xylene) are easily discriminated using only two different coatings with three different QCM responses. All chemicals were easily separated and detected with a total of 5 films and 6 responses with >99% accuracy.

  7. Experimental Determination of Chemical Diffusion within Secondary Organic Aerosol Particles

    SciTech Connect

    Abramson, Evan H.; Imre, D.; Beranek, Josef; Wilson, Jacqueline; Zelenyuk, Alla

    2013-02-28

    Formation, properties, transformations, and temporal evolution of secondary organic aerosols (SOA) particles strongly depend on particle phase. Recent experimental evidence from a number of groups indicates that SOA is in a semi-solid phase, the viscosity of which remained unknown. We find that when SOA is made in the presence of vapors of volatile hydrophobic molecules the SOA particles absorb and trap them. Here, we illustrate that it is possible to measure the evaporation rate of these molecules that is determined by their diffusion in SOA, which is then used to calculate a reasonably accurate value for the SOA viscosity. We use pyrene as a tracer molecule and a-pinene SOA as an illustrative case. It takes ~24 hours for half the pyrene to evaporate to yield a viscosity of 10^8 Pa s for a-pinene. This viscosity is consistent with measurements of particle bounce and evaporation rates. We show that viscosity of 10^8 Pa s implies coalescence times of minutes, consistent with the findings that SOA particles are spherical. Similar measurements on aged SOA particles doped with pyrene yield a viscosity of 10^9 Pa s, indicating that hardening occurs with time, which is consistent with observed decrease in water uptake and evaporation rate with aging.

  8. Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment.

    PubMed

    Booij, Kees; Robinson, Craig D; Burgess, Robert M; Mayer, Philipp; Roberts, Cindy A; Ahrens, Lutz; Allan, Ian J; Brant, Jan; Jones, Lisa; Kraus, Uta R; Larsen, Martin M; Lepom, Peter; Petersen, Jördis; Pröfrock, Daniel; Roose, Patrick; Schäfer, Sabine; Smedes, Foppe; Tixier, Céline; Vorkamp, Katrin; Whitehouse, Paul

    2016-01-05

    We reviewed compliance monitoring requirements in the European Union, the United States, and the Oslo-Paris Convention for the protection of the marine environment of the North-East Atlantic, and evaluated if these are met by passive sampling methods for nonpolar compounds. The strengths and shortcomings of passive sampling are assessed for water, sediments, and biota. Passive water sampling is a suitable technique for measuring concentrations of freely dissolved compounds. This method yields results that are incompatible with the EU's quality standard definition in terms of total concentrations in water, but this definition has little scientific basis. Insufficient quality control is a present weakness of passive sampling in water. Laboratory performance studies and the development of standardized methods are needed to improve data quality and to encourage the use of passive sampling by commercial laboratories and monitoring agencies. Successful prediction of bioaccumulation based on passive sampling is well documented for organisms at the lower trophic levels, but requires more research for higher levels. Despite the existence of several knowledge gaps, passive sampling presently is the best available technology for chemical monitoring of nonpolar organic compounds. Key issues to be addressed by scientists and environmental managers are outlined.

  9. EPA project-level research strategies for chemical mixtures: targeted research for meaningful results.

    PubMed

    Teuschler, Linda K; Hertzberg, Richard C; Rice, Glenn E; Simmons, Jane Ellen

    2004-12-01

    Project-level research strategies at the U.S. Environmental Protection Agency regarding chemical mixtures are impacted by administrative priorities, public interests, expert opinions, scientific advances, regulatory needs, and legislative actions, influencing the setting of priorities and goals. Perhaps, the most significant influence on conducting chemical mixtures research is the passage of laws requiring the EPA to investigate the potential toxicity of various mixtures, specifically the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, the Food Quality Protection Act of 1996, and the Safe Drinking Water Act Amendments of 1996. Scarce resources are allocated to broadly defined issues for consideration by teams of scientists, who design and implement specific projects. Because resources are limited, projects may have several goals, e.g., filling specific data gaps to support a regulation and, simultaneously, producing data to evaluate a risk assessment method. Research areas of emphasis are shaped by risk assessment needs, data gap uncertainties, and experimental design considerations. This paper discusses factors shaping EPA research strategies for chemical mixtures and presents an example of efficient research planning to investigate potential toxicity from exposure to drinking water disinfection by-products.

  10. From consumption to harvest: Environmental fate prediction of excreted ionizable trace organic chemicals.

    PubMed

    Polesel, Fabio; Plósz, Benedek Gy; Trapp, Stefan

    2015-11-01

    Excreted trace organic chemicals, e.g., pharmaceuticals and biocides, typically undergo incomplete elimination in municipal wastewater treatment plants (WWTPs) and are released to surface water via treated effluents and to agricultural soils through sludge amendment and/or irrigation with freshwater or reclaimed wastewater. Recent research has shown the tendency for these substances to accumulate in food crops. In this study, we developed and applied a simulation tool to predict the fate of three ionizable trace chemicals (triclosan-TCS, furosemide-FUR, ciprofloxacin-CIP) from human consumption/excretion up to the accumulation in soil and plant, following field amendment with sewage sludge or irrigation with river water (assuming dilution of WWTP effluent). The simulation tool combines the SimpleTreat model modified for fate prediction of ionizable chemicals in a generic WWTP and a recently developed dynamic soil-plant uptake model. The simulation tool was tested using country-specific (e.g., consumption/emission rates, precipitation and temperature) input data. A Monte Carlo-based approach was adopted to account for the uncertainty associated to physico-chemical and biokinetic model parameters. Results obtained in this study suggest significant accumulation of TCS and CIP in sewage sludge (1.4-2.8 mg kgDW(-1)) as compared to FUR (0.02-0.11 mg kgDW(-1)). For the latter substance, more than half of the influent load (60.1%-72.5%) was estimated to be discharged via WWTP effluent. Specific emission rates (g ha(-1) a(-1)) of FUR to soil via either sludge application or irrigation were up to 300 times lower than for TCS and CIP. Nevertheless, high translocation potential to wheat was predicted for FUR, reaching concentrations up to 4.3 μg kgDW(-1) in grain. Irrigation was found to enhance the relative translocation of FUR to plant (45.3%-48.9% of emission to soil), as compared to sludge application (21.9%-27.6%). A comparison with peer-reviewed literature showed

  11. Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: July--September 1997

    SciTech Connect

    Jubin, R.T.

    1998-07-01

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period July--September 1997. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within nine major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Biotechnology, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information.

  12. Improved exposure estimation in soil screening and clean-up criteria for volatile organic chemicals.

    PubMed

    DeVaull, George E

    2017-02-18

    Soil clean-up criteria define acceptable concentrations of organic chemical constituents for exposed humans. These criteria sum the estimated soil exposure over multiple pathways. Assumptions for ingestion, dermal contact, and dust exposure generally presume a chemical persists in surface soils at a constant concentration level for the entire exposure duration. For volatile chemicals this is an unrealistic assumption. A calculation method is presented for surficial soil criteria which include volatile depletion of chemical for these uptake pathways. The depletion estimates compare favorably with measured concentration profiles and with field measurements of soil concentration. Corresponding volatilization estimates compare favorably with measured data for a wide range of volatile and semi-volatile chemicals, including instances with and without the presence of a mixed-chemical residual phase. Selected examples show application of the revised factors in estimating screening levels for benzene in surficial soils. This article is protected by copyright. All rights reserved.

  13. Sorption of hydrophobic organic chemicals to organic colloids in a freshwater wetland system: Temporal and spatial variations

    SciTech Connect

    Backhus, D.A.; Castellanos, E.; Fast, S.; Golini, C.

    1995-12-01

    Despite the fact that organic colloids are often found in wetland systems in greater abundance than in most other aquatic systems, little work has been done to examine their role in the cycling of organic pollutants. Heightened concern for the degradation of valuable wetland habitat and proposals to use constructed wetlands as treatment options for nonpoint sources of pollution provide a need for examination of organic pollutant:mobile organic colloid interactions in wetlands. A study is underway to determine the quantity, quality, and sorptive properties of colloidal organic matter collected from freshwater wetland systems. Surface water and porewater samples from a coastal freshwater wetland on the shores of Lake Erie (Old Woman Creek) were collected, stored, and analyzed using methods which allow for maintenance of in situ conditions. Sorption experiments were conducted. to the extent possible, on unaltered samples (e.g., examining whole water samples under in situ conditions rather than resuspending processed/concentrated/fractionated organic matter in artificial media). Fluorescence quenching methods were implemented to quantify sorption coefficients of appropriate organic chemical probes (e.g., perylene). To date, three locations within the wetland have been sampled at two time points (Summer and Fall). Initial results suggest that organic colloids in this wetland are present in lower quantities and in general exhibit lower sorption potential than humic and fulvic materials reported in the literature. Significant variations in the sorptive properties of organic colloids have been observed both temporally and spatially in this wetland.

  14. Uptake and mobilization of organic chemicals with clouds: evidence from a hail sample.

    PubMed

    Ma, Jianmin; Sverko, Ed; Su, Yushan; Zhang, Junhua; Gao, Hong

    2013-09-03

    Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were measured in hail samples collected during a storm that occurred on a spring morning in Toronto, Canada. The presence of these organic chemicals in hail suggests that clouds likely provide an atmospheric transport pathway for these substances in the free atmosphere. Results reported here may carry significant implications for atmospheric transport, mass balance, tropospheric cold trapping, and environmental fate of organic chemicals. Backward trajectories along with measured and modeled cloud cover show that clouds causing the hail event were formed and advected from the midwestern and southeastern United States. After being emitted to the atmosphere, the organic chemicals were likely lifted by atmospheric ascending motions to a higher atmospheric elevation and partitioned onto clouds. These clouds then carry the organic chemicals to a downwind location where they are deposited to the ground surface via precipitation. We found that the organic chemicals with high solubility and vapor pressure tend to partition into clouds through sorption to cloudwater droplets and ice particles. It was found that approximately 7-30% of pyrene could be sorbed into cloudwater droplets and ice particles in this hail event at the expense of reduced gas-phase concentrations.

  15. Mammalian models of chemically induced primary malignancies exploitable for imaging-based preclinical theragnostic research

    PubMed Central

    Liu, Yewei; Yin, Ting; Feng, Yuanbo; Cona, Marlein Miranda; Huang, Gang; Liu, Jianjun; Song, Shaoli; Jiang, Yansheng; Xia, Qian; Swinnen, Johannes V.; Bormans, Guy; Himmelreich, Uwe; Oyen, Raymond

    2015-01-01

    Compared with transplanted tumor models or genetically engineered cancer models, chemically induced primary malignancies in experimental animals can mimic the clinical cancer progress from the early stage on. Cancer caused by chemical carcinogens generally develops through three phases namely initiation, promotion and progression. Based on different mechanisms, chemical carcinogens can be divided into genotoxic and non-genotoxic ones, or complete and incomplete ones, usually with an organ-specific property. Chemical carcinogens can be classified upon their origins such as environmental pollutants, cooked meat derived carcinogens, N-nitroso compounds, food additives, antineoplastic agents, naturally occurring substances and synthetic carcinogens, etc. Carcinogen-induced models of primary cancers can be used to evaluate the diagnostic/therapeutic effects of candidate drugs, investigate the biological influential factors, explore preventive measures for carcinogenicity, and better understand molecular mechanisms involved in tumor initiation, promotion and progression. Among commonly adopted cancer models, chemically induced primary malignancies in mammals have several advantages including the easy procedures, fruitful tumor generation and high analogy to clinical human primary cancers. However, in addition to the time-consuming process, the major drawback of chemical carcinogenesis for translational research is the difficulty in noninvasive tumor burden assessment in small animals. Like human cancers, tumors occur unpredictably also among animals in terms of timing, location and the number of lesions. Thanks to the availability of magnetic resonance imaging (MRI) with various advantages such as ionizing-free scanning, superb soft tissue contrast, multi-parametric information, and utility of diverse contrast agents, now a workable solution to this bottleneck problem is to apply MRI for noninvasive detection, diagnosis and therapeutic monitoring on those otherwise

  16. Chemically Selective Coated Quartz Crystal Microbalance (QCM) Array for Detection of Volatile Organic Chemicals

    SciTech Connect

    Bohuszewicz, T.V.; Frye-Mason, G.C.; Martin, S.J.; Osbourn, G.C. Bartholomew, J.W.; Schneider, T.W.; Spates, J.J.

    1998-11-04

    Liquid flow cells have been fabricated to prepare an array of QCMS operating simultaneously for detection and identification of VOCS in water. TWO signals, a tlequency response and a damping voltage response, were obtained per resonator. A blank QCM was used as a reference to account for changes in liquid density and viscosity. Nine different polymer coatings applied using a spin coat technique have been examined for VOC response under liquid flow conditions. A matrix of three classes of VOCS were examined for each coating with four chemicals in each class. The three classes of VOCS are polar, nonpolar and chlorinated. A pattern recognition technique, called visually empirical region of influence (VERI), was used to cluster the responses in n-dimensional space. Chemicals within a class varying by only one methyl group (e.g., toluene and xylene) are easily discriminated using only two different coatings with three different QCM responses. All chemicak were easily separated and detected with a total of 5 films and 6 responses with >99% accuracy.

  17. Tooth Matrix Analysis for Biomonitoring of Organic Chemical Exposure: Current Status, Challenges, and Opportunities

    PubMed Central

    Andra, Syam S.; Austin, Christine; Arora, Manish

    2015-01-01

    Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers to

  18. Tooth matrix analysis for biomonitoring of organic chemical exposure: Current status, challenges, and opportunities.

    PubMed

    Andra, Syam S; Austin, Christine; Arora, Manish

    2015-10-01

    Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro-odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps: (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers

  19. The contribution of organization theory to nursing health services research.

    PubMed

    Mick, Stephen S; Mark, Barbara A

    2005-01-01

    We review nursing and health services research on health care organizations over the period 1950 through 2004 to reveal the contribution of nursing to this field. Notwithstanding this rich tradition and the unique perspective of nursing researchers grounded in patient care production processes, the following gaps in nursing research remain: (1) the lack of theoretical frameworks about organizational factors relating to internal work processes; (2) the need for sophisticated methodologies to guide empirical investigations; (3) the difficulty in understanding how organizations adapt models for patient care delivery in response to market forces; (4) the paucity of attention to the impact of new technologies on the organization of patient care work processes. Given nurses' deep understanding of the inner workings of health care facilities, we hope to see an increasing number of research programs that tackle these deficiencies.

  20. Pilot survey of methamphetamine in sewers using a Polar Organic Chemical Integrative Sampler.

    PubMed

    Boles, Tammy H; Wells, Martha J M

    2014-02-15

    A pilot study for the qualitative detection of methamphetamine at sites within a sewage collection system adjacent to locations suspected to harbor illegal drug activities was investigated and preliminary findings are reported. Sewage samples were collected over a time interval of four weeks using a Polar Organic Chemical Integrative Sampler (POCIS) deployed directly into the sewer line. The POCIS sorbent was extracted and analyzed via high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Methamphetamine was found in sewage from one of three sampling sites at a concentration greater than the HPLC-MS/MS method detection limit (MDL) of 3 ng/mL. The goal of this research was to establish proof-of-concept of the feasibility for sampling and analysis using POCIS devices in the sewage collection system. The data encourage further testing and research. The ability to pinpoint the presence of methamphetamine in the sewer may in the future be used as a forensic tool in law enforcement.

  1. Adult Education and Aging: Perspectives on Research at a Private Independent Research Organization.

    ERIC Educational Resources Information Center

    Russ-Eft, Darlene

    As part of a symposium on challenges and problems of adult education researchers in different settings, recent research activities at one private independent research organization were examined. Three projects of the American Instituties for Research (AIR) were reviewed, all relating to adult development and aging. The first examined career…

  2. Measuring indigenous photosynthetic organisms to detect chemical warefare agents in water

    DOEpatents

    Greenbaum, Elias; Sanders, Charlene A.

    2005-11-15

    A method of testing water to detect the presence of a chemical or biological warfare agent is disclosed. The method is carried out by establishing control data by providing control water containing indigenous organisms but substantially free of a chemical and a biological warfare agent. Then measuring photosynthetic activity of the control water with a fluorometer to obtain control data to compare with test data to detect the presence of the chemical or agent. The test data is gathered by providing test water comprising the same indigenous organisms as contained in the control water. Further, the test water is suspected of containing the chemical or agent to be tested for. Photosynthetic activity is also measured by fluorescence induction in the test water using a fluorometer.

  3. The healthy organization construct: A review and research agenda

    PubMed Central

    Raya, Rampalli Prabhakara; Panneerselvam, Sivapragasam

    2013-01-01

    Work plays an important role in one's life for many reasons. It provides us with economic, social, and personal satisfaction and accounts for a substantial percentage of our waking hours. But in today's knowledge-driven economy, organization of work has been changing at a warp speed as a consequence of economic, social and technological aspects of changes brought down by globalization and liberalization worldwide. While this situation has eliminated some risks of the earlier industrial era, it is introducing others. In such a dynamic business environment, where can business leaders and managers find competitive advantage? It lies in balancing people and performance goals. This is the line of approach for healthy organization research that examines organizational context with regard to: People, work organization, management practices, employee wellbeing and performance. The healthy organization concept proposes that along with the profits, employee's well being should also be an important goal for organizations. In this paper, the researcher undertakes an extensive review of literature in the mainstream business literature and establishes the agenda for healthy organization research among other research paradigms. PMID:24872666

  4. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    SciTech Connect

    Apel, E.; Springston, S.; Karl, T.; Emmons, L.; Flocke, F.; Hills, A. J.; Madronich, S.; Lee-Taylor, J.; Fried, A.; Weibring, P.; Walega, J.; Richter, D., Tie, X.; Mauldin, L.; Campos, T.; Sive, B.; Kleinman, L.; Springston, S., Zaveri, R.; deGouw, J.; Zheng, J.; Zhang, R.; Rudolph, J.; Junkermann, W.; Riemer, D. D.

    2009-11-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on 18 March and the NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the 19 March plume and to help interpret the OH

  5. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    SciTech Connect

    Apel, Eric; Emmons, L.; Karl, Thomas G.; Flocke, Frank M.; Hills, A. J.; Madronich, Sasha; Lee-Taylor, J.; Fried, Alan; Weibring, P.; Walega, J.; Richter, Dirk; Tie, X.; Mauldin, L.; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Sive, B.; Kleinman, Lawrence I.; Springston, S.; Zaveri, Rahul A.; Ortega, John V.; Voss, Paul B.; Blake, D. R.; Baker, Angela K.; Warneke, Carsten; Welsh-Bon, Daniel; de Gouw, Joost A.; Zheng, J.; Zhang, Renyi; Rudolph, Jochen; Junkermann, W.; Riemer, D.

    2010-01-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on March 18 and the NCAR C130 one day later on March 19. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the March 19 plume and to help interpret the OH

  6. Partitioning of polar and non-polar neutral organic chemicals into human and cow milk.

    PubMed

    Geisler, Anett; Endo, Satoshi; Goss, Kai-Uwe

    2011-10-01

    The aim of this work was to develop a predictive model for milk/water partition coefficients of neutral organic compounds. Batch experiments were performed for 119 diverse organic chemicals in human milk and raw and processed cow milk at 37°C. No differences (<0.3 log units) in the partition coefficients of these types of milk were observed. The polyparameter linear free energy relationship model fit the calibration data well (SD=0.22 log units). An experimental validation data set including hormones and hormone active compounds was predicted satisfactorily by the model. An alternative modelling approach based on log K(ow) revealed a poorer performance. The model presented here provides a significant improvement in predicting enrichment of potentially hazardous chemicals in milk. In combination with physiologically based pharmacokinetic modelling this improvement in the estimation of milk/water partitioning coefficients may allow a better risk assessment for a wide range of neutral organic chemicals.

  7. Toxicity testing of organic chemicals in groundwater polluted with landfill leachate

    SciTech Connect

    Baun, A.; Kloeft, L.; Bjerg, P.L.; Nyholm, N.

    1999-09-01

    A method for assessment of toxicity of nonvolatile organic chemicals contaminants in groundwater polluted with landfill leachate has been evaluated. The biotests utilized were composed of an algal growth inhibition test (Selenastrum capricornutum), a daphnia immobilization test (Daphnia magna), and a bacterial genotoxicity test (umuC, Salmonella typhimurium). The feasibility of the selected biotests was investigated for a series of groundwater samples collected along pollution gradients downstreams of two landfills in Jutland, Denmark. Two different approaches were used, direct toxicity testing of whole groundwater samples, and toxicity testing of concentrates obtained by solid-phase extraction. Direct testing of whole groundwater samples produced toxic responses, but the complex sample matrix masked the toxicity of the organic chemical contaminants of interest. Solid-phase extraction was used successfully as an on-site method that eliminated ion toxicity and produced biotest responses that reflected the toxicity of the nonvolatile organic chemical contaminants in the groundwater.

  8. Effects of chemical aging on global secondary organic aerosol using the volatility basis set approach

    NASA Astrophysics Data System (ADS)

    Jo, D. S.; Park, R. J.; Kim, M. J.; Spracklen, D. V.

    2013-12-01

    A global 3-D chemical transport model (GEOS-Chem) is used with the volatility basis set (VBS) approach to examine the effects of chemical aging on global secondary organic aerosol (SOA) concentrations and budgets. We present full-year simulations and their comparisons with the global aerosol mass spectrometer (AMS) dataset, the Interagency Monitoring of Protected Visual Environments (IMPROVE) dataset from the United States, the European Monitoring and Evaluation Programme (EMEP) dataset from Europe, and water-soluble organic carbon observation data collected over East Asia. Using different chemical aging constants, we find that the model results with 4 × 10-11 cm3 molecule-1 s-1 are in better agreement with all observations relative to the model results with other aging constants, without aging, and with the two-product approach. The model simulations are improved when chemical aging is considered, especially for rural regions. However, the simulations still underestimate observed oxygenated organic aerosol (OOA) in urban areas. Two sensitivity simulations including semi-volatile primary organic aerosol (POA) were conducted. We find that including semi-volatile POA improves the model in terms of the hydrogen-like organic aerosol (HOA) to OOA ratio. However, the total OA concentrations are not improved. The total SOA production is considerably increased by 53%, from 26.0 to 39.9 Tg yr-1, after considering chemical aging, remaining lower than top-down estimates of SOA production. Direct radiative forcing (DRF) increases by -0.07 W m-2 due to the chemical aging of SOA, which is comparable to the mean DRF (-0.13 W m-2) of OA from the AeroCom multi-model study. This result indicates considerable global and, more importantly, regional climate implications. For example, the regional DRF change due to chemical aging of SOA in the eastern US is -0.29 W m-2, which is 4 times greater in magnitude than the global mean value.

  9. 15 CFR Supplement No. 2 to Part 715 - Examples of Unscheduled Discrete Organic Chemicals (UDOCs) and UDOC Production

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Organic Chemicals (UDOCs) and UDOC Production No. Supplement No. 2 to Part 715 Commerce and Foreign Trade... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 2 Supplement No. 2 to Part 715—Examples of Unscheduled Discrete...

  10. 15 CFR Supplement No. 2 to Part 715 - Examples of Unscheduled Discrete Organic Chemicals (UDOCs) and UDOC Production

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Organic Chemicals (UDOCs) and UDOC Production No. Supplement No. 2 to Part 715 Commerce and Foreign Trade... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 2 Supplement No. 2 to Part 715—Examples of Unscheduled Discrete...

  11. 15 CFR Supplement No. 2 to Part 715 - Examples of Unscheduled Discrete Organic Chemicals (UDOCs) and UDOC Production

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Organic Chemicals (UDOCs) and UDOC Production No. Supplement No. 2 to Part 715 Commerce and Foreign Trade... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 2 Supplement No. 2 to Part 715—Examples of Unscheduled Discrete...

  12. 15 CFR Supplement No. 2 to Part 715 - Examples of Unscheduled Discrete Organic Chemicals (UDOCs) and UDOC Production

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Organic Chemicals (UDOCs) and UDOC Production No. Supplement No. 2 to Part 715 Commerce and Foreign Trade... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC CHEMICALS (UDOCs) Pt. 715, Supp. 2 Supplement No. 2 to Part 715—Examples of Unscheduled Discrete...

  13. Natural and active chemical remediation of toxic metals, organics, and radionuclides in the aquatic environment

    SciTech Connect

    McPherson, G.; Pintauro, P.; O`Connor, S.

    1996-05-02

    This project focuses on the chemical aspects of remediation, with the underlying theme that chemical remediation does occur naturally. Included are studies on the fate of heavy metal and organic contaminants discharged into aquatic environments; accurate assay metal contaminants partitioned into soils, water and tissue; development of novel polymeric membranes and microporous solids for the entrapment of heavy metals; and the development of hybrid chemo-enzymatic oxidative schemes for aromatics decontamination. 49 refs.

  14. The effect of the indoor environment on the fate of organic chemicals in the urban landscape.

    PubMed

    Cousins, Anna Palm

    2012-11-01

    To assess the effect of the indoor environment on the urban fate of organic chemicals, an 8-compartment indoor-inclusive steady state multimedia chemical fate model was developed. The model includes typical urban compartments (air, soil, water, sediment, and urban film) and a novel module representing a generic indoor environment. The model was parameterized to the municipality of Stockholm, Sweden and applied to four organic chemicals with different physical-chemical characteristics and use patterns: formaldehyde, 2,4,6-tribromophenol, di-ethylhexylphthalate and decabromodiphenyl ether. The results show that emissions to indoor air may increase the steady state mass and residence time in the urban environment by a factor of 1.1 to 22 for the four chemicals, compared to if emissions are assigned to outdoor air. This is due to the nested nature of the indoor environment, which creates a physical barrier that prevents chemicals from leaving the urban system with outflowing air. For DEHP and BDE 209, the additional partitioning to indoor surfaces results in a greater importance of the indoor removal pathways from surfaces. The outdoor environmental concentrations of these chemicals are predicted to be lower if emitted to indoor air than if emitted to outdoor air because of the additional indoor removal pathways of dust and indoor film, leading to loss of chemical from the system. For formaldehyde and 2,4,6-TBP outdoor environmental concentrations are not affected by whether the release occurs indoors or outdoors because of the limited partitioning to indoor surfaces. A sensitivity analysis revealed that there appears to be a relationship between logK(OA) and the impact of the ventilation rate on the urban fate of organic chemicals.

  15. In vitro model systems for studying the impact of organic chemicals on the skin barrier lipids.

    PubMed

    Groen, Daniël; Berthaud, Fabienne; Bouwstra, Joke A; Chapuis, Christian; Gooris, Gert S; Boncheva, Mila

    2014-01-01

    This paper describes two synthetic lipid models designed to replace human stratum corneum (SC) in studies of the impact of volatile organic chemicals on the molecular organization of the skin barrier lipids. The models built upon previously developed self-assembled lipid membranes which have composition and 3D organization similar to those of the lipid matrix in SC. In one model the target chemicals were incorporated in the lipids before their self-assembly, and in the other one they were applied on top of a preformed lipid membrane. The chemicals could be incorporated within the model membranes in quantities close to those reached within human SC upon heavy surface loading. The dose-dependent effects of the chemicals on the lateral molecular organization in the models were qualitatively identical to those observed by infrared spectroscopy in human SC. The models facilitated the interpretation of X-ray diffraction profiles used to determine the nature of the interactions between the chemicals and the lipid lamellae and the position of the exogenous molecules within the unit cell of the lipid phases. These model systems are suitable for in vitro studies in the areas of skin biophysics, dermatology, transdermal drug delivery, and risk assessment.

  16. Clinical trials and contract research organizations in India.

    PubMed

    Mukherjee, Shoibal

    2012-06-01

    Economics and demography are driving drug development to the developing world. India needs this opportunity to build research skills required to combat its enormous disease burden. A variety of global and local contract research organizations (CROs) that specialize in the execution of research to develop health care products operate in India today. CROs assure quality and compliance to regulations while coordinating with tertiary providers such as a site management organization and the central laboratory. Back room operations to manage, analyze, and report data form a bulk of the employment generated by clinical research, absorbing programmers, data managers, biostatisticians,and medical writers. Despite rapid growth and strong potential, India remains a minor contributor to global pharmaceutical research because of policy stagnation, regulatory gaps, and misinformed controversies in the media.

  17. Evaluation of a multimedia model for predicting the environmental fate of organic chemicals in Canada

    SciTech Connect

    Kane, D.M.; Mackay, D.

    1995-12-31

    Health Canada is required to assess human health risks associated with the introduction of new chemicals for commercial use in Canada. An important initial step in this assessment process is the estimation of expected concentrations of a particular new chemical in various environmental media such as air, water, sail, and sediment. These concentrations can then form the basis for subsequent calculations of human exposure. A fugacity-based multimedia exposure model (CHEMCAN3) was developed for these assessments which describes the chemical`s fate in the environment based on its physical chemical properties, reactivity, transport characteristics and emissions. This paper presents the results of a validation exercise comparing the predictions of the model against measured data. CHEMCAN3 was applied to the prediction of the environmental fate of a set of 10 organic chemicals. The predictions were then compared to available environmental monitoring data for these chemicals, The test set included 5 industrial chemicals and 5 commonly used pesticides; benzene, chlorobenzene, hexachlorobenzene, toluene, dichloromethane, di(2-ethylhexyl) phthalate, atrazine, dinoseb, lindane, parathion, and 2,4-dichlorophenoxyacetic acid. The Southern Ontario region of Canada was used as the environment for the model predictions. The results show that the model successfully predicts the environmental behavior of the chemicals, with 82% agreement within one order of magnitude between predicted and measured values. This result lends confidence to the use of this model, and similar models, for prediction of environmental fate and as a basis for exposure assessment.

  18. A combined deuterium NMR and quantum chemical investigation of inequivalent hydrogen bonds in organic solids.

    PubMed

    Webber, Renee; Penner, Glenn H

    2012-01-01

    Deuterium magic angle spinning (MAS) NMR spectroscopy and quantum chemical calculations are used to investigate organic solids in which inequivalent hydrogen bonds are present. The use of (2)H MAS allows one to measure the chemical shift, δ, quadrupolar coupling constant, C(Q), and asymmetry in the quadrupolar interaction, η(Q), for each type of hydrogen bond present in the system. Quantum chemical calculations of the magnetic shielding (σ, which can be related to δ) and the electric field gradient (EFG, which can be related to C(Q)) are compared to the experimental results and are discussed with respect to the relative strengths of the hydrogen bonds within each system.

  19. Effects of water temperature on the toxicity of chemicals to aquatic organisms

    SciTech Connect

    Mayer, F.; Brecken-Folse, J.; Howe, G.; Linton, T.

    1995-12-31

    Water temperatures fluctuate regularly in aquatic environments, producing physiological and ecological changes in resident biota. Temperature has been recognized as a critical factor affecting the toxicity of chemicals by altering the physiological condition of the biota and the interactions between organisms and toxicants. Temperature significantly affects respiration rates, chemical absorption, and chemical detoxification and excretion. Acute toxicity of most chemicals to aquatic organisms is positively correlated with temperature; however, the toxicity of some chemicals is negatively correlated with or not affected by temperature. Regression slopes of toxicity appear consistent among species within a chemical for temperature, indicating chemical rather than biological differences in toxicity. Temperature may not affect acute toxicity per se, but does affect bioavailability and, therefore, exposure. Octanol/water partition coefficients are altered by temperature and could replace some biological testing since the partition coefficient-acute toxicity relationship has been well established. Temperature may only alter the rate of intoxication in chronic exposures no-effect concentrations do not appear to be affected by temperature; only the time required to attain the same no-effect concentration varies.

  20. Detailed Chemical Characterization of Unresolved Complex Mixtures (UCM) inAtmospheric Organics: Insights into Emission Sources, Atmospheric Processing andSecondary Organic Aerosol Formation

    EPA Science Inventory

    Recent studies suggest that semivolatile organic compounds (SVOCs) are important precursors to secondary organic aerosol (SOA) in urban atmospheres. However, knowledge of the chemical composition of SVOCs is limited by current analytical techniques, which are typically unable to...

  1. Research Integrity and Research Ethics in Professional Codes of Ethics: Survey of Terminology Used by Professional Organizations across Research Disciplines

    PubMed Central

    Komić, Dubravka; Marušić, Stjepan Ljudevit; Marušić, Ana

    2015-01-01

    Professional codes of ethics are social contracts among members of a professional group, which aim to instigate, encourage and nurture ethical behaviour and prevent professional misconduct, including research and publication. Despite the existence of codes of ethics, research misconduct remains a serious problem. A survey of codes of ethics from 795 professional organizations from the Illinois Institute of Technology’s Codes of Ethics Collection showed that 182 of them (23%) used research integrity and research ethics terminology in their codes, with differences across disciplines: while the terminology was common in professional organizations in social sciences (82%), mental health (71%), sciences (61%), other organizations had no statements (construction trades, fraternal social organizations, real estate) or a few of them (management, media, engineering). A subsample of 158 professional organizations we judged to be directly involved in research significantly more often had statements on research integrity/ethics terminology than the whole sample: an average of 10.4% of organizations with a statement (95% CI = 10.4-23-5%) on any of the 27 research integrity/ethics terms compared to 3.3% (95% CI = 2.1–4.6%), respectively (P<0.001). Overall, 62% of all statements addressing research integrity/ethics concepts used prescriptive language in describing the standard of practice. Professional organizations should define research integrity and research ethics issues in their ethics codes and collaborate within and across disciplines to adequately address responsible conduct of research and meet contemporary needs of their communities. PMID:26192805

  2. Research Integrity and Research Ethics in Professional Codes of Ethics: Survey of Terminology Used by Professional Organizations across Research Disciplines.

    PubMed

    Komić, Dubravka; Marušić, Stjepan Ljudevit; Marušić, Ana

    2015-01-01

    Professional codes of ethics are social contracts among members of a professional group, which aim to instigate, encourage and nurture ethical behaviour and prevent professional misconduct, including research and publication. Despite the existence of codes of ethics, research misconduct remains a serious problem. A survey of codes of ethics from 795 professional organizations from the Illinois Institute of Technology's Codes of Ethics Collection showed that 182 of them (23%) used research integrity and research ethics terminology in their codes, with differences across disciplines: while the terminology was common in professional organizations in social sciences (82%), mental health (71%), sciences (61%), other organizations had no statements (construction trades, fraternal social organizations, real estate) or a few of them (management, media, engineering). A subsample of 158 professional organizations we judged to be directly involved in research significantly more often had statements on research integrity/ethics terminology than the whole sample: an average of 10.4% of organizations with a statement (95% CI = 10.4-23-5%) on any of the 27 research integrity/ethics terms compared to 3.3% (95% CI = 2.1-4.6%), respectively (P<0.001). Overall, 62% of all statements addressing research integrity/ethics concepts used prescriptive language in describing the standard of practice. Professional organizations should define research integrity and research ethics issues in their ethics codes and collaborate within and across disciplines to adequately address responsible conduct of research and meet contemporary needs of their communities.

  3. Bandgap tuning of mixed organic cation utilizing chemical vapor deposition process

    PubMed Central

    Kim, Jeongmo; Kim, Hyeong Pil; Teridi, Mohd Asri Mat; Yusoff, Abd. Rashid bin Mohd; Jang, Jin

    2016-01-01

    Bandgap tuning of a mixed organic cation perovskite is demonstrated via chemical vapor deposition process. The optical and electrical properties of the mixed organic cation perovskite can be manipulated by varying the growth time. A slight shift of the absorption band to shorter wavelengths is demonstrated with increasing growth time, which results in the increment of the current density. Hence, based on the optimized growth time, our device exhibits an efficiency of 15.86% with negligible current hysteresis. PMID:27874026

  4. Nanoscale chemical tomography of buried organic-inorganic interfaces in the chiton tooth.

    PubMed

    Gordon, Lyle M; Joester, Derk

    2011-01-13

    Biological organisms possess an unparalleled ability to control the structure and properties of mineralized tissues. They are able, for example, to guide the formation of smoothly curving single crystals or tough, lightweight, self-repairing skeletal elements. In many biominerals, an organic matrix interacts with the mineral as it forms, controls its morphology and polymorph, and is occluded during mineralization. The remarkable functional properties of the resulting composites-such as outstanding fracture toughness and wear resistance-can be attributed to buried organic-inorganic interfaces at multiple hierarchical levels. Analysing and controlling such interfaces at the nanometre length scale is critical also in emerging organic electronic and photovoltaic hybrid materials. However, elucidating the structural and chemical complexity of buried organic-inorganic interfaces presents a challenge to state-of-the-art imaging techniques. Here we show that pulsed-laser atom-probe tomography reveals three-dimensional chemical maps of organic fibres with a diameter of 5-10 nm in the surrounding nano-crystalline magnetite (Fe(3)O(4)) mineral in the tooth of a marine mollusc, the chiton Chaetopleura apiculata. Remarkably, most fibres co-localize with either sodium or magnesium. Furthermore, clustering of these cations in the fibre indicates a structural level of hierarchy previously undetected. Our results demonstrate that in the chiton tooth, individual organic fibres have different chemical compositions, and therefore probably different functional roles in controlling fibre formation and matrix-mineral interactions. Atom-probe tomography is able to detect this chemical/structural heterogeneity by virtue of its high three-dimensional spatial resolution and sensitivity across the periodic table. We anticipate that the quantitative analysis and visualization of nanometre-scale interfaces by laser-pulsed atom-probe tomography will contribute greatly to our understanding not

  5. Estimation of the annual yield of organic carbon released from carbonates and shales by chemical weathering

    NASA Astrophysics Data System (ADS)

    Di-Giovanni, Christian; Disnar, Jean Robert; Macaire, Jean Jacques

    2002-04-01

    The aim of this paper is to propose an initial estimation of the annual organic matter yield induced by chemical weathering of carbonates and shales, considering their global surface at outcrop and their organic matter content. The calculation also uses data on river fluxes resulting from carbonate rocks and shales weathering in major world watersheds, published by numerous authors. The results obtained from the studied watersheds have then been extrapolated to a global scale. Despite rather large uncertainty to such an approach, the calculated value of ca. 0.1 Gt implies that the annual organic carbon yield related to carbonates and shales chemical weathering might be a non-negligible component of the global carbon cycle. The individual contributions of different watersheds necessarily depend on the organic matter content of altered rocks. They are also obviously controlled by climatic parameters. The calculated yields do not constitute a direct supply to soils and rivers because of mineralisation when organic carbon is brought in contact with the atmosphere. Even so, the release of fossil organic matter would have implications for the global carbon cycle through the efficiency of the global chemical weathering as a carbon sink. Whatever the chosen hypothesis, the results of this study suggest that the recycled organic yield is a neglected component in the global organic carbon cycle assessment. Because it exists and, in addition, because it might represent a non-negligible carbon pool, fossil organic carbon deserves to be taken into account for a better evaluation of the organic stocks in soils and rivers presently only based on climatic data and current vegetal production.

  6. Building Research Relationships With Managed Care Organizations: Issues and Strategies

    PubMed Central

    LEIN, CATHERINE; COLLINS, CLARE; LYLES, JUDITH S.; HILLMAN, DONALD; SMITH, ROBERT C.

    2006-01-01

    Managed care is now the dominant form of healthcare in the United States. The need for clinical research about the organization, delivery, and outcomes of primary care services in managed care models is high, yet access to managed care organizations as sites for clinical research may be problematic. The purpose of this article is to describe issues involved in obtaining access to managed care settings for clinical research and practical strategies for successful collaboration using literature review and case description. Three steps for developing collaborative relationships with managed care organizations (MCOs) are presented: 1) assessment of organizational structure, history, and culture; 2) finding common ground; and 3) project implementation. These steps are discussed within the context of MCO systems issues and a relationship-centered approach to communication between researchers and individuals from the MCO. Successful relationships with MCOs for clinical research are possible when careful attention is paid to inclusion of MCOs as collaborators in the development of the research questions and design, and as partners in the research implementation process. PMID:17203136

  7. First reported fatalities associated with the 'research chemical' 2-methoxydiphenidine.

    PubMed

    Elliott, Simon P; Brandt, Simon D; Wallach, Jason; Morris, Hamilton; Kavanagh, Pierce V

    2015-05-01

    2-Methoxydiphenidine, i.e. 1-[1-(2-methoxyphenyl)-2-phenylethyl]piperidine, also known as 'MXP' or '2-MeO-diphenidine' (or 2-MXP), has been available as a 'research chemical' since 2013 as a purported alternative to the 'dissociative anesthetics' methoxetamine and ketamine. Three deaths which involved the detection of 2-MXP in post-mortem blood and urine were encountered in forensic casework. The 2-, 3- and 4-methoxyphenyl positional isomers were synthesized to confirm the identity and concentration of 2-MXP. The 2-MXP femoral blood concentrations in the cases were found to be 24.0, 2.0 and 1.36 mg/L (the latter with an alternative cause of death). Some additional prescription drugs were encountered at therapeutic concentrations in all three cases. Analysis of the biofluids allowed the detection and characterization of various metabolites, including the suggested presence of hydroxy-2-MXP as the main metabolite with the hydroxyl group located on the piperidine rather than the phenyl or benzyl moiety. Additional metabolites included O-desmethyl-2-MXP and hydroxylated O-desmethyl-2-MXP. Diphenidine and hydroxy-diphenidine, also showing the presence of the hydroxyl group on the piperidine ring, were also detected. It was not possible to identify whether these arose from 2-MXP biotransformation or whether they represented the presence of diphenidine as a separate substance. These are the first published fatalities involving 2-MXP and presents analytical data to assist analytical toxicologists with future casework.

  8. Screening organic chemicals in commerce for emissions in the context of environmental and human exposure.

    PubMed

    Breivik, Knut; Arnot, Jon A; Brown, Trevor N; McLachlan, Michael S; Wania, Frank

    2012-08-01

    Quantitative knowledge of organic chemical release into the environment is essential to understand and predict human exposure as well as to develop rational control strategies for any substances of concern. While significant efforts have been invested to characterize and screen organic chemicals for hazardous properties, relatively less effort has been directed toward estimating emissions and hence also risks. Here, a rapid throughput method to estimate emissions of discrete organic chemicals in commerce has been developed, applied and evaluated to support screening studies aimed at ranking and identifying chemicals of potential concern. The method builds upon information in the European Union Technical Guidance Document and utilizes information on quantities in commerce (production and/or import rates), chemical function (use patterns) and physical-chemical properties to estimate emissions to air, soil and water within the OECD for five stages of the chemical life-cycle. The method is applied to 16,029 discrete substances (identified by CAS numbers) from five national and international high production volume lists. As access to consistent input data remains fragmented or even impossible, particular attention is given to estimating, evaluating and discussing uncertainties in the resulting emission scenarios. The uncertainty for individual substances typically spans 3 to 4 orders of magnitude for this initial tier screening method. Information on uncertainties in emissions is useful as any screening or categorization methods which solely rely on threshold values are at risk of leading to a significant number of either false positives or false negatives. A limited evaluation of the screening method's estimates for a sub-set of about 100 substances, compared against independent and more detailed emission scenarios presented in various European Risk Assessment Reports, highlights that up-to-date and accurate information on quantities in commerce as well as a detailed

  9. Biological and Chemical Technologies Research at OIT: Annual Summary Report, FY 1997

    SciTech Connect

    Peterson, G.

    1998-03-01

    The annual summary report presents the fiscal year (FY) 1 997 research activities and accomplishments for the United States Department of Energy (DOE) Biological and Chemical Technologies Research (BCTR) Program. This BCTR program resides within the Office of Industrial Technologies (OIT) of the Office of Energy Efficiency and Renewable Energy (EE). The annual summary report for 1997 (ASR 97) contains the following: program description (including BCTR program mission statement, historical background, relevance, goals and objectives); program structure and organization; selected technical and programmatic highlights for 1 997; detailed descriptions of individual projects; and a listing of program output, including a bibliography of published work, patents, and awards arising from work supported by the program.

  10. AICD -- Advanced Industrial Concepts Division Biological and Chemical Technologies Research Program. 1993 Annual summary report

    SciTech Connect

    Petersen, G.; Bair, K.; Ross, J.

    1994-03-01

    The annual summary report presents the fiscal year (FY) 1993 research activities and accomplishments for the United States Department of Energy (DOE) Biological and Chemical Technologies Research (BCTR) Program of the Advanced Industrial Concepts Division (AICD). This AICD program resides within the Office of Industrial Technologies (OIT) of the Office of Energy Efficiency and Renewable Energy (EE). The annual summary report for 1993 (ASR 93) contains the following: A program description (including BCTR program mission statement, historical background, relevance, goals and objectives), program structure and organization, selected technical and programmatic highlights for 1993, detailed descriptions of individual projects, a listing of program output, including a bibliography of published work, patents, and awards arising from work supported by BCTR.

  11. Attenuation of total organic carbon and unregulated trace organic chemicals in U.S. riverbank filtration systems.

    PubMed

    Hoppe-Jones, Christiane; Oldham, Gretchen; Drewes, Jörg E

    2010-08-01

    There is increasing concern regarding the presence of unregulated trace organic chemicals in drinking water supplies that receive discharge from municipal wastewater treatment plants. In comparison to conventional and advanced drinking water treatment, riverbank filtration represents a low-cost and low-energy alternative that can attenuate total organic carbon (TOC) as well as trace organic chemicals (TOrC). This study examined the role of predominant redox conditions, retention time, biodegradable organic carbon, and temperature to achieve attenuation of TOC and TOrC through monitoring efforts at three full-scale RBF facilities in different geographic areas of the United States. The RBF systems investigated in this study were able to act as a reliable barrier for TOC, nitrogen, and certain TOrC. Temperature (seasonal) variation played an important role for the make-up of the river water quality and performance of the RBF systems. Temperatures of less than 10 degrees C did not affect TOC removal but resulted in diminished attenuation of nitrate and select TOrC.

  12. Comparison of dermal and inhalation routes of entry for organic chemicals

    NASA Technical Reports Server (NTRS)

    Jepson, Gary W.; Mcdougal, James N.; Clewell, Harvey J., III

    1992-01-01

    The quantitative comparison of the chemical concentration inside the body as the result of a dermal exposure versus an inhalation exposure is useful for assessing human health risks and deciding on an appropriate protective posture. In order to describe the relationship between dermal and inhalation routes of exposure, a variety of organic chemicals were evaluated. The types of chemicals chosen for the study were halogenated hydrocarbons, aromatic compounds, non-polar hydrocarbons and inhalation anesthetics. Both dermal and inhalation exposures were conducted in rats and the chemicals were in the form of vapors. Prior to the dermal exposure, rat fur was closely clipped and during the exposure rats were provided fresh breathing air through latex masks. Blood samples were taken during 4-hour exposures and analyzed for the chemical of interest. A physiologically based pharmacokinetic model was used to predict permeability constants (cm/hr) consistent with the observed blood concentrations of the chemical. The ratio of dermal exposure to inhalation exposure required to achieve the same internal dose of chemical was calculated for each test chemical. The calculated ratio in humans ranged from 18 for styrene to 1180 for isoflurane. This methodology can be used to estimate the dermal exposure required to reach the internal dose achieved by a specific inhalation exposure. Such extrapolation is important since allowable exposure standards are often set for inhalation exposures, but occupational exposures may be dermal.

  13. A Review of Research on the Teaching and Learning of Chemical Kinetics

    ERIC Educational Resources Information Center

    Bain, Kinsey; Towns, Marcy H.

    2016-01-01

    We review literature on the teaching and learning of chemical kinetics at both the secondary and tertiary levels. Our aim in doing so is to summarize research literature, synthesize recommendations for future research, and suggest implications for practitioners. Two main bodies of literature emerged from the chemical kinetics education research:…

  14. Predicting soil sorption coefficients of organic chemicals using a neural network model

    SciTech Connect

    Gao, C.; Govind, R.; Tabak, H.H.

    1996-07-01

    The soil/sediment adsorption partition coefficient normalized to organic carbon (K{sub oc}) is extensively used to assess the fate of organic chemicals in hazardous waste sites. Several attempts have been made to estimate the value of K{sub oc} from chemical structure or its parameters. The primary purpose of this study was to develop a nonlinear model for estimating K{sub oc} applicable to polar and nonpolar organics based on artificial neural networks using the octanol/water partition coefficient (K{sub ow}) and water solubility (S). An analytic equation was obtained by starting with a neural network, converging the bias and weight values using the available data on water solubility, octanol/water partition coefficient, and the normalized soil/sediment adsorption partition coefficient, and then combining the equations for each node in the final neural network. For the 119 chemicals in the training set, estimates using the neural network equation lie outside the 2{sigma} region (the standard deviation for the training set, {sigma} = 0.52) for only five chemicals, while all the chemicals in the test set lie within the 2{sigma} region. It was concluded that the neural network equation outperforms the linear models in fitting the K{sub oc} values for the training set and predicting them for the test set.

  15. Chemical and toxicologic assessment of organic contaminants in surface water using passive samplers

    USGS Publications Warehouse

    Alvarez, D.A.; Cranor, W.L.; Perkins, S.D.; Clark, R.C.; Smith, S.B.

    2008-01-01

    Passive sampling methodologies were used to conduct a chemical and toxicologic assessment of organic contaminants in the surface waters of three geographically distinct agricultural watersheds. A selection of current-use agrochemicals and persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides, were targeted using the polar organic chemical integrative sampler (POCIS) and the semipermeable membrane device passive samplers. In addition to the chemical analysis, the Microtox assay for acute toxicity and the yeast estrogen screen (YES) were conducted as potential assessment tools in combination with the passive samplers. During the spring of 2004, the passive samplers were deployed for 29 to 65 d at Leary Weber Ditch, IN; Morgan Creek, MD; and DR2 Drain, WA. Chemical analysis of the sampler extracts identified the agrochemicals predominantly used in those areas, including atrazine, simazine, acetochlor, and metolachlor. Other chemicals identified included deethylatrazine and deisopropylatrazine, trifluralin, fluoranthene, pyrene, cis- and trans-nonachlor, and pentachloroanisole. Screening using Microtox resulted in no acutely toxic samples. POCIS samples screened by the YES assay failed to elicit a positive estrogenic response. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  16. Prediction of the sorption capacities and affinities of organic chemicals by XAD-7.

    PubMed

    Yang, Kun; Qi, Long; Wei, Wei; Wu, Wenhao; Lin, Daohui

    2016-01-01

    Macro-porous resins are widely used as adsorbents for the treatment of organic contaminants in wastewater and for the pre-concentration of organic solutes from water. However, the sorption mechanisms for organic contaminants on such adsorbents have not been systematically investigated so far. Therefore, in this study, the sorption capacities and affinities of 24 organic chemicals by XAD-7 were investigated and the experimentally obtained sorption isotherms were fitted to the Dubinin-Ashtakhov model. Linear positive correlations were observed between the sorption capacities and the solubilities (SW) of the chemicals in water or octanol and between the sorption affinities and the solvatochromic parameters of the chemicals, indicating that the sorption of various organic compounds by XAD-7 occurred by non-linear partitioning into XAD-7, rather than by adsorption on XAD-7 surfaces. Both specific interactions (i.e., hydrogen-bonding interactions) as well as nonspecific interactions were considered to be responsible for the non-linear partitioning. The correlation equations obtained in this study allow the prediction of non-linear partitioning using well-known chemical parameters, namely SW, octanol-water partition coefficients (KOW), and the hydrogen-bonding donor parameter (αm). The effect of pH on the sorption of ionizable organic compounds (IOCs) could also be predicted by combining the correlation equations with additional equations developed from the estimation of IOC dissociation rates. The prediction equations developed in this study and the proposed non-linear partition mechanism shed new light on the selective removal and pre-concentration of organic solutes from water and on the regeneration of exhausted XAD-7 using solvent extraction.

  17. Adsorptive removal and separation of chemicals with metal-organic frameworks: Contribution of π-complexation.

    PubMed

    Khan, Nazmul Abedin; Jhung, Sung Hwa

    2017-03-05

    Efficient removal and separation of chemicals from the environment has become a vital issue from a biological and environmental point of view. Currently, adsorptive removal/separation is one of the most promising approaches for cleaning purposes. Selective adsorption/removal of various sulfur- and nitrogen-containing compounds, olefins, and π-electron-rich gases via π-complex formation between an adsorbent and adsorbate molecules is very competitive. Porous metal-organic framework (MOF) materials are very promising in the adsorption/separation of various liquids and gases owing to their distinct characteristics. This review summarizes the literature on the adsorptive removal/separation of various π-electron-rich compounds mainly from fuel and gases using MOF materials containing metal ions that are active for π-complexation. Details of the π-complexation, including mechanism, pros/cons, applications, and efficient ways to form the complex, are discussed systematically. For in-depth understanding, molecular orbital calculations regarding charge transfer between the π-complexing species are also explained in a separate section. From this review, readers will gain an understanding of π-complexation for adsorption and separation, especially with MOFs, to develop new insight for future research.

  18. Incorporating Chemical Information Instruction and Environmental Science into the First-Year Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Landolt, R. G.

    2006-01-01

    The chemical information instruction and environmental science which is incorporated into a first-year organic chemistry laboratory is presented. The students are charged with devised search strategies, conducting online searches and limiting the project scope to ocean systems. The laboratory serves to provide for search strategy development…

  19. Experts Workshop on the Ecotoxicological Risk Assessment of Ionizable Organic Chemicals: Bioaccumulation/ADME

    EPA Science Inventory

    The bioaccumulation potential of neutral organic chemicals (e.g., PCBs, DDT, brominated flame retardants) has received a great deal of attention from scientists in the field of environment toxicology and chemistry over the past four decades. Regulations based on our understanding...

  20. An efficient laboratory workflow for environmental risk assessment of organic chemicals.

    PubMed

    Zhu, Linyan; Santiago-Schübel, Beatrix; Xiao, Hongxia; Thiele, Björn; Zhu, Zhiliang; Qiu, Yanling; Hollert, Henner; Küppers, Stephan

    2015-07-01

    In this study, we demonstrate a fast and efficient workflow to investigate the transformation mechanism of organic chemicals and evaluate the toxicity of their transformation products (TPs) in laboratory scale. The transformation process of organic chemicals was first simulated by electrochemistry coupled online to mass spectrometry (EC-MS). The simulated reactions were scaled up in a batch EC reactor to receive larger amounts of a reaction mixture. The mixture sample was purified and concentrated by solid phase extraction (SPE) for the further ecotoxicological testing. The combined toxicity of the reaction mixture was evaluated in fish egg test (FET) (Danio rerio) compared to the parent compound. The workflow was verified with carbamazepine (CBZ). By using EC-MS seven primary TPs of CBZ were identified; the degradation mechanism was elucidated and confirmed by comparison to literature. The reaction mixture and one primary product (acridine) showed higher ecotoxicity in fish egg assay with 96 h EC50 values of 1.6 and 1.0 mg L(-1) than CBZ with the value of 60.8 mg L(-1). The results highlight the importance of transformation mechanism study and toxicological effect evaluation for organic chemicals brought into the environment since transformation of them may increase the toxicity. The developed process contributes a fast and efficient laboratory method for the risk assessment of organic chemicals and their TPs.

  1. Interdisciplinary Learning for Chemical Engineering Students from Organic Chemistry Synthesis Lab to Reactor Design to Separation

    ERIC Educational Resources Information Center

    Armstrong, Matt; Comitz, Richard L.; Biaglow, Andrew; Lachance, Russ; Sloop, Joseph

    2008-01-01

    A novel approach to the Chemical Engineering curriculum sequence of courses at West Point enabled our students to experience a much more realistic design process, which more closely replicated a real world scenario. Students conduct the synthesis in the organic chemistry lab, then conduct computer modeling of the reaction with ChemCad and…

  2. Organic contaminant release from melting snow. 1. Influence of chemical partitioning.

    PubMed

    Meyer, Torsten; Lei, Ying Duan; Muradi, Ibrahim; Wania, Frank

    2009-02-01

    A melting snowpack can deliver organic contaminants to terrestrial and aquatic ecosystems in the form of short and concentrated pulses. The mechanisms and kinetics of the underlying processes need to be understood to successfully integrate them into contaminant and water quality models. Controlled laboratory-based snowmelt experiments using artificially produced snow spiked with organic target contaminants reveal how chemical behavior during melting is dependent on the partitioning between the different phases within the bulk snow. Behaving similar to inorganic ions, water soluble organic chemicals, such as atrazine, are preferentially released at an early stage of melting, because such chemicals, accumulated at the snow grain surface, dissolve in the downward percolating meltwaterfront. Hydrophobic substances attached to particles, such as the larger polycyclic aromatic hydrocarbons, are often released at the very end of the melt period, because particle coagulation and snow densification render the melting snowpack an efficient filter trapping the particles. A notable fraction of volatile chemicals, such as naphthalene, will transfer from the melting snowpack to the lower atmosphere due to evaporation. Organic pollutants with intermediate partition properties, such as lindane, can easily switch between the bulk snow phases and their elution behavior is therefore more sensitive to varying snow and melt characteristics.

  3. Pheromones, attractants and other chemical cues of aquatic organisms and amphibians.

    PubMed

    Cummins, Scott F; Bowie, John H

    2012-06-01

    This review covers the subject of pheromones, attractants and other chemical cues of aquatic invertebrates, fishes and amphibians (including salamanders and anurans). Major topics include the sex pheromones of gastropods, salamanders and a giant tree frog, and the conspecific attraction of sperm to ova of some of the organisms and animals described in this review.

  4. Evaluation of OECD guidelines for testing of chemicals with aquatic organisms

    SciTech Connect

    Blaylock, B.G.; McCarthy, J.F.; Frank, M.L.; Singley, P.T.

    1983-10-01

    The protocols in the OECD (Organization for Economic Cooperation and Development) guidelines for testing of chemicals with aquatic organisms were evaluated for the following tests: (1) Fish, Acute Toxicity Test, (2) Bioaccumulation: Flow-through Fish Test, (3) Daphnia sp., 14-day Reproduction Test (including an Acute Immobilization Test), and (4) Alga, Growth Inhibition Test. The protocols were evaluated by conducting the tests with different classes of chemicals (i.e., water soluble, less water soluble requiring a chemical carrier, and volatile chemical). Flow-through and semistatic Fish, Acute Toxicity Tests were conducted with cupric chloride and acridine. The Bioaccumulation Flow-Through Fish Test was conducted with naphthalene and DDE. Three chemicals - cupric chloride, acridine, and di-n-butyl phthalate - were used to evaluate the Daphnia sp., 14-day Reproduction Test. The Alga, Growth Inhibition Test was evaluated with three chemicals: cupric chloride, acridine, and paradichlorobenzene. By following the OECD guidelines in conducting these tests, results were obtained that are comparable with literature data obtained with other methods. An evaluation of each test protocol is given with recommendations for the guidelines for conducting the tests.

  5. Factors affecting the uptake of 14C-labeled organic chemicals by plants from soil

    SciTech Connect

    Topp, E.; Scheunert, I.; Attar, A.; Korte, F.

    1986-04-01

    The uptake of /sup 14/C from various /sup 14/C-labeled organic chemicals from different chemical classes by barley and cress seedlings from soil was studied for 7 days in a closed aerated laboratory apparatus. Uptake by roots and by leaves via the air was determined separately. Although comparative long-term outdoor studies showed that an equilibrium is not reached within a short time period, plant concentration factors after 7 days could be correlated to some physicochemical and structural substance properties. Barley root concentration factors due to root uptake, expressed as concentration in roots divided by concentration in soil, gave a fairly good negative correlation to adsorption coefficients based on soil organic carbon. Barley root concentration factors, expressed as concentration in roots divided by concentration in soil liquid, gave a positive correlation to the n-octanol/water partition coefficients. Uptake of chemicals by barley leaves via air was strongly positively correlated to volatilization of chemicals from soil. Both root and foliar uptake by barley could be correlated well to the molecular weight of 14 chemicals. Uptake of chemicals by cress differed from that by barley, and correlations to physicochemical substance properties mostly were poor.

  6. Top value platform chemicals: bio-based production of organic acids.

    PubMed

    Becker, Judith; Lange, Anna; Fabarius, Jonathan; Wittmann, Christoph

    2015-12-01

    Driven by the quest for sustainability, recent years have seen a tremendous progress in bio-based production routes from renewable raw materials to commercial goods. Particularly, the production of organic acids has crystallized as a competitive and fast-evolving field, related to the broad applicability of organic acids for direct use, as polymer building blocks, and as commodity chemicals. Here, we review recent advances in metabolic engineering and industrial market scenarios with focus on organic acids as top value products from biomass, accessible through fermentation and biotransformation.

  7. Distribution of organic carbon and chemicals in agricultural soils (BET method)

    NASA Astrophysics Data System (ADS)

    Schnitzler, F.; Séquaris, J.-M.; Berns, A. E.; Burauel, P.

    2009-04-01

    Modelling the dynamics of soil organic carbon and chemicals in soils requires compartmentalisation in pools or fractions. The determination of organic carbon and chemical concentration in all fractions is often time-consuming or not realisable due to low amount of soil fractions. Therefore, we developed an analytical method to calculate distributions of organic carbon and chemicals in soil without any chemical extraction method. Two sets of experiments were conducted with undisturbed soil columns under field-like conditions. In the first set, maize straw was incorporated into the topsoil and after three months incubation, the 14C-labelled chemicals benazolin or benzo[a]pyrene were applied. The second set was treated equally, but without maize addition. After a total incubation time of six months, the topsoil layers were fractionated with a physical aggregate size fractionation procedure[1]. The content of organic carbon and the distribution of the chemicals were detected in the gained soil fractions. Furthermore, the BET method was used to determine the specific surface area (SSA) of selected soil fractions. It can be shown that a fraction of organic carbon and chemicals is dependent on the SSA. The slopes of these linear relationships have been used for the estimation of the organic carbon[2] or chemicals associated to the clay fraction. Thus, mass concentrations of organic carbon or chemicals located in the clay and silt+sand fraction can be calculated. It has been found that the influence of the incorporated maize straw on the amount of organic carbon in the fractions is low due to strong mineralisation processes. In general, the amount of organic carbon in the silt+sand fraction is higher than in the clay fraction. In contrary, the 14C-activity of the chemicals is higher in the clay fraction than in the silt+sand fraction. However, the addition of maize straw increases the amount of 14C-activity in the silt+sand fraction. The calculated distribution

  8. Formic and Acetic Acid Observations over Colorado by Chemical Ionization Mass Spectrometry and Organic Acids' Role in Air Quality

    NASA Astrophysics Data System (ADS)

    Treadaway, V.; O'Sullivan, D. W.; Heikes, B.; Silwal, I.; McNeill, A.

    2015-12-01

    Formic acid (HFo) and acetic acid (HAc) have both natural and anthropogenic sources and a role in the atmospheric processing of carbon. These organic acids also have an increasing importance in setting the acidity of rain and snow as precipitation nitrate and sulfate concentrations have decreased. Primary emissions for both organic acids include biomass burning, agriculture, and motor vehicle emissions. Secondary production is also a substantial source for both acids especially from biogenic precursors, secondary organic aerosols (SOAs), and photochemical production from volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). Chemical transport models underestimate organic acid concentrations and recent research has sought to develop additional production mechanisms. Here we report HFo and HAc measurements during two campaigns over Colorado using the peroxide chemical ionization mass spectrometer (PCIMS). Iodide clusters of both HFo and HAc were recorded at mass-to-charge ratios of 173 and 187, respectively. The PCIMS was flown aboard the NCAR Gulfstream-V platform during the Deep Convective Clouds and Chemistry Experiment (DC3) and aboard the NCAR C-130 during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The DC3 observations were made in May and June 2012 extending from the surface to 13 km over the central and eastern United States. FRAPPE observations were made in July and August 2014 from the surface to 7 km over Colorado. DC3 measurements reported here are focused over the Colorado Front Range and complement the FRAPPE observations. DC3 HFo altitude profiles are characterized by a decrease up to 6 km followed by an increase either back to boundary layer mixing ratio values or higher (a "C" shape). Organic acid measurements from both campaigns are interpreted with an emphasis on emission sources (both natural and anthropogenic) over Colorado and in situ photochemical production especially ozone precursors.

  9. Hardware Modifications to the US Army Research Laboratory’s Metalorganic Chemical Vapor Deposition (MOCVD) System for Optimization of Complex Oxide Thin Film Fabrication

    DTIC Science & Technology

    2015-04-01

    melanie.w.cole.civ@mail.mil. 14. ABSTRACT An introduction to various metalorganic chemical vapor deposition (MOCVD) reactor designs and precursor...flow and chemical reactions occurring in the reactor chamber at the substrate surface. A substantial amount of research has been dedicated to...coupled showerhead MOCVD reactor . Microelectronics Journal. 2009;40:280–282. 8. Wessels BW. Metal-organic chemical -vapor-deposition of ferroelectric

  10. Physico-Chemical Research on the Sounding Rocket Maser 13

    NASA Astrophysics Data System (ADS)

    Lockowandt, Christian; Kemi, Stig; Abrahamsson, Mattias; Florin, Gunnar

    MASER is a sounding rocket platform for short-duration microgravity experiments, providing the scientific community with an excellent microgravity tool. The MASER programme has been running by SSC from 1987 and has up to 2012 provided twelve successful flights for microgravity missions with 6-7 minutes of microgravity, the g-level is normally below 1x10-5 g. The MASER 13 is planned to be launched in spring 2015 from Esrange Space Center in Northern Sweden. The rocket will carry four ESA financed experiment modules. The MASER 13 vehicle will be propelled by the 2-stage solid fuel VSB-30 rocket motor, which provided the 390 kg payload with an apogee of 260 km and 6 and a half minutes of microgravity. Swedish Space Corporation carries out the MASER missions for ESA and the program is also available for other customers. The payload comprise four different experiment modules of which three could be defined as physic-chemical research; XRMON-SOL, CDIC-3, MEDI. It also comprises the Maser Service Module and the recovery system. The Service Module provided real-time 5 Mbps down-link of compressed experiment digital video data from the on-board cameras, as well as high-speed housekeeping telemetry data. XRMON-SOL In this experiment the influence of gravity on the formation of an equiaxed microstructure will be investigated. Special attention will be put on the aspect of nucleation, segregation and impingement. The experiment scope is to melt and solidify an AlCu-alloy sample in microgravity. The solidification will be performed in an isothermal environment. The solidification process will be monitored and recorded with X-ray image during the whole flight, images will also be down-linked to ground for real-time monitoring and possible interaction. CDIC-3 The goal is to study in migrogravity the spatio-temporal dynamics of a chemical front travelling in a thin solution layer open to the air and specifically the respective role of Marangoni and density-related hydrodynamic

  11. Applying a marketing perspective to health research organizations.

    PubMed

    McDermott, D R; Tuckman, H P

    1997-01-01

    An excellent way for health research organizations to raise funds is by applying a well-executed marketing plan. Such a plan should include four steps: performing an environmental/internal audit, performing a services marketing audit, performing a relationship marketing audit, and developing a set of marketing strategies and tactics.

  12. Research on radiation detectors, boiling transients, and organic lubricants

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The accomplishments of a space projects research facility are presented. The subjects discussed are: (1) a study of radiation resistant semiconductor devices, (2) synthesis of high temperature organic lubricants, (3) departure from phase equilibrium during boiling transients, (4) effects of neutron irradiation on defect state in tungsten, and (5) determination of photon response function of NE-213 liquid scintillation detectors.

  13. Frontiers in Chemical Engineering. Research Needs and Opportunities.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Commission on Physical Sciences, Mathematics, and Resources.

    Chemical engineers play a key role in industries such as petroleum, food, artificial fibers, petrochemicals, plastics and many others. They are needed to tailor manufacturing technology to the requirements of products and to integrate product and process design. This report discusses how chemical engineers are continuing to address technological…

  14. Calculation of NMR chemical shifts in organic solids: accounting for motional effects.

    PubMed

    Dumez, Jean-Nicolas; Pickard, Chris J

    2009-03-14

    NMR chemical shifts were calculated from first principles for well defined crystalline organic solids. These density functional theory calculations were carried out within the plane-wave pseudopotential framework, in which truly extended systems are implicitly considered. The influence of motional effects was assessed by averaging over vibrational modes or over snapshots taken from ab initio molecular dynamics simulations. It is observed that the zero-point correction to chemical shifts can be significant, and that thermal effects are particularly noticeable for shielding anisotropies and for a temperature-dependent chemical shift. This study provides insight into the development of highly accurate first principles calculations of chemical shifts in solids, highlighting the role of motional effects on well defined systems.

  15. A general mathematical model for chemical-enhanced flushing of soil contaminated by organic compounds

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Brusseau, Mark L.

    The use of chemical agents to enhance the in situ removal of hydrophobic organic compounds (HOCs) from porous media is an emerging remediation technology. Whereas surfactants and cosolvents are the primary agents examined to date, others, such as natural organic matter and complexing agents, have also been examined for their ability to enhance the solubilization of HOCs. While the mode of action of each type of enhanced-solubilization agent may be different, they all induce similar responses. In this paper, a general mathematical model is developed to simulate the enhanced-solubilization process for various chemical agents, including cosolvents, surfactants, natural organic matter, and complexing agents. This model is developed using a master-equation approach that incorporates the solubilization mechanisms associated with each type of agent. A limited evaluation of the model is conducted by comparing simulations to the results of two laboratory experiments. A sensitivity analysis is performed to illustrate the influence of various factors on contaminant removal.

  16. SOLUBILITY, SORPTION AND TRANSPORT OF HYDROPHOBIC ORGANIC CHEMICALS IN COMPLEX MIXTURES

    EPA Science Inventory

    The research summarized in this report focuses on the effects which organic cosolvents have on the sorption and mobility of organic contaminants. This work was initiated In an effort to improve our understanding of the environmental consequences associated with complex mixtur...

  17. Biodegradation of organic chemicals in soil/water microcosms system: Model development

    USGS Publications Warehouse

    Liu, L.; Tindall, J.A.; Friedel, M.J.; Zhang, W.

    2007-01-01

    The chemical interactions of hydrophobic organic contaminants with soils and sediments may result in strong binding and slow subsequent release rates that significantly affect remediation rates and endpoints. In order to illustrate the recalcitrance of chemical to degradation on sites, a sorption mechanism of intraparticle sequestration was postulated to operate on chemical remediation sites. Pseudo-first order sequestration kinetics is used in the study with the hypothesis that sequestration is an irreversibly surface-mediated process. A mathematical model based on mass balance equations was developed to describe the fate of chemical degradation in soil/water microcosm systems. In the model, diffusion was represented by Fick's second law, local sorption-desorption by a linear isotherm, irreversible sequestration by a pseudo-first order kinetics and biodegradation by Monod kinetics. Solutions were obtained to provide estimates of chemical concentrations. The mathematical model was applied to a benzene biodegradation batch test and simulated model responses correlated well compared to measurements of biodegradation of benzene in the batch soil/water microcosm system. A sensitivity analysis was performed to assess the effects of several parameters on model behavior. Overall chemical removal rate decreased and sequestration increased quickly with an increase in the sorption partition coefficient. When soil particle radius, a, was greater than 1 mm, an increase in radius produced a significant decrease in overall chemical removal rate as well as an increase in sequestration. However, when soil particle radius was less than 0.1 mm, an increase in radius resulted in small changes in the removal rate and sequestration. As pseudo-first order sequestration rate increased, both chemical removal rate and sequestration increased slightly. Model simulation results showed that desorption resistance played an important role in the bioavailability of organic chemicals in porous

  18. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests

    NASA Astrophysics Data System (ADS)

    Guo, Xiaoping; Meng, Miaojing; Zhang, Jinchi; Chen, Han Y. H.

    2016-07-01

    Changes in the chemical composition of soil organic carbon (SOC) might strongly affect the global carbon cycle as it controls the SOC decomposition rate. Vegetation change associated with long-term land use changes is known to strongly impact the chemical composition of SOC; however, data on the impacts of vegetation change following disturbance events of short durations and succession that occur frequently in forest ecosystems via diverse management objectives on SOC chemical composition are negligible. Here we examined the impacts of vegetation changes on the chemical composition of SOC by sampling soils of native broad-leaved forests, planted mixed broad-leaved and coniferous forests, and tea gardens in eastern China. We used nuclear magnetic resonance spectroscopy to quantify SOC chemical composition. We found that among all components of SOC chemical composition, alkyl carbon (C) and aryl C were more liable to change with vegetation than other SOC components. Soil pH was negatively correlated to the relative abundances of alkyl C and N-alkyl C, and Shannon’s index of overstory plant species was positively correlated to the relative abundances of phenolic C and aromaticity. Our results suggest that vegetation changes following short disturbance events and succession may strongly alter SOC chemical composition in forest ecosystems.

  19. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests

    PubMed Central

    Guo, Xiaoping; Meng, Miaojing; Zhang, Jinchi; Chen, Han Y. H.

    2016-01-01

    Changes in the chemical composition of soil organic carbon (SOC) might strongly affect the global carbon cycle as it controls the SOC decomposition rate. Vegetation change associated with long-term land use changes is known to strongly impact the chemical composition of SOC; however, data on the impacts of vegetation change following disturbance events of short durations and succession that occur frequently in forest ecosystems via diverse management objectives on SOC chemical composition are negligible. Here we examined the impacts of vegetation changes on the chemical composition of SOC by sampling soils of native broad-leaved forests, planted mixed broad-leaved and coniferous forests, and tea gardens in eastern China. We used nuclear magnetic resonance spectroscopy to quantify SOC chemical composition. We found that among all components of SOC chemical composition, alkyl carbon (C) and aryl C were more liable to change with vegetation than other SOC components. Soil pH was negatively correlated to the relative abundances of alkyl C and N-alkyl C, and Shannon’s index of overstory plant species was positively correlated to the relative abundances of phenolic C and aromaticity. Our results suggest that vegetation changes following short disturbance events and succession may strongly alter SOC chemical composition in forest ecosystems. PMID:27403714

  20. [Chemical Loss of Volatile Organic Compounds and Its Impact on the Formation of Ozone in Shanghai].

    PubMed

    Wang, Hong-li

    2015-09-01

    The spatial characterization of ozone (O3) and its precursors was studied based on the field measurements in urban and rural areas of Shanghai during the summer of 2014. The chemical loss of volatile organic compounds (VOCs) was estimated by the parameterization method. The mixing ratio of VOCs was 20 x 10(-9) in urban area and 17 x 10(-9) in the west rural area during the measurements. The average values of the maximum incremental reactivity were comparable in urban and rural areas, namely 5. 0 mol.mol-1 (O3/VOCs). By contrast, the chemical loss of VOCs was 8. 3 x 10(-9) in west rural area, which was two times as that in urban area. The more chemical loss of VOCs was probably one of the important reasons leading to the higher O3 concentration in west rural area. The regional transport might be important reason of the variation of O3 in the eastern coastal rural area. The chemical loss of VOCs showed good agreement with the local formation of O3 in both urban and rural areas, suggesting a similar efficiency of O3 formation from the chemical loss of VOCs. Among the chemical loss, aromatics and alkenes are the dominant VOC species of the atmospheric chemistry which accounts for more than 90% . The diurnal profile of VOC chemical loss matched well with the production of O3 with one-hour postponement.

  1. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests.

    PubMed

    Guo, Xiaoping; Meng, Miaojing; Zhang, Jinchi; Chen, Han Y H

    2016-07-11

    Changes in the chemical composition of soil organic carbon (SOC) might strongly affect the global carbon cycle as it controls the SOC decomposition rate. Vegetation change associated with long-term land use changes is known to strongly impact the chemical composition of SOC; however, data on the impacts of vegetation change following disturbance events of short durations and succession that occur frequently in forest ecosystems via diverse management objectives on SOC chemical composition are negligible. Here we examined the impacts of vegetation changes on the chemical composition of SOC by sampling soils of native broad-leaved forests, planted mixed broad-leaved and coniferous forests, and tea gardens in eastern China. We used nuclear magnetic resonance spectroscopy to quantify SOC chemical composition. We found that among all components of SOC chemical composition, alkyl carbon (C) and aryl C were more liable to change with vegetation than other SOC components. Soil pH was negatively correlated to the relative abundances of alkyl C and N-alkyl C, and Shannon's index of overstory plant species was positively correlated to the relative abundances of phenolic C and aromaticity. Our results suggest that vegetation changes following short disturbance events and succession may strongly alter SOC chemical composition in forest ecosystems.

  2. Influence of organic cosolvents on sorption of hydrophobic organic chemicals by soils

    SciTech Connect

    Nkedi-Kizza, P.; Rao, P.S.C.; Hornsby, A.G.

    1985-10-01

    Sorption of anthracene and two herbicides (diuron and atrazine) by soils from aqueous solutions and binary solvent mixtures consisting of methanol-water and acetone-water was measured. These data were used to evaluate recently proposed solvophobic theory for describing sorption of hydrophobic molecules from mixed solvents. As predicted by the theory, the sorption coefficient (K/sup m/) decreased exponentially with increasing fraction of the organic cosolvent (f/sup c/) in the binary solvent mixtures. The slope of the ln K/sup m/ vs. f/sup c/ plot, designated as sigma/sup c/, was unique to each sorbate-solvent combination and was independent of the soil (sorbent). Thus, the organic cosolvent effects on sorption could be specified by a single parameter that combines the coefficients characterizing solvent and sorbate properties. The sigma/sup c/ value was shown to be directly proportional to the solvent-sorbate interfacial free energy( ..delta gamma../sup c/) and the hydrocarbonaceous molecular surface area (HSA) of the sorbate.

  3. Characterization of Organic Nitrate Formation in Limonene Secondary Organic Aerosol using High-Resolution Chemical Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Faxon, Cameron; Hammes, Julia; Peng, Jianfei; Hallquist, Mattias; Pathak, Ravi

    2016-04-01

    Previous work has shown that organic nitrates (RONO2) are prevalent in the boundary layer, and can contribute significantly to secondary organic aerosol formation. Monoterpenes, including limonene, have been shown to be precursors for the formation of these organic nitrates. Limonene has two double bonds, either of which may be oxidized by NO3 or O3. This leads to the generation of products that can subsequently condense or partition into the particle phase, producing secondary organic aerosol. In order to further elucidate the particle and gas phase product distribution of organic nitrates forming from the reactions of limonene and the nitrate radical (NO3), a series of experiments were performed in the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures (G-FROST), described by previous work. N2O5 was used as the source for NO3 and NO2, and a characterized diffusion source was used to introduce limonene into the flow reactor. All experiments were conducted in the absence of light, and the concentration of limonene was increased step-wise throughout each experiment to modify the ratio of N2O5to limonene. The experiments were conducted such that both limonene- and N2O5-limited regimes were present. Gas and particle phase products were measured using an iodide High-Resolution Time-of-Flight Mass Spectrometer (HR-ToF-CIMS) coupled to a Filter Inlet for Gases and AEROsols (FIGAERO, and particle size and SOA mass concentrations were derived using a Scanning Mobility Particle Sizer (SMPS). CIMS measurement techniques have previously been employed for the measurement of organic nitrate products of such compounds using multiple reagent ions. The use of this instrumentation allowed for the identification of chemical formulas for gas and particle phase species. The findings from the experiments will be presented in terms of the relative gas-particle partitioning of major products and the effects of N2O5/limonene ratios on product distributions. Additionally, a

  4. A novel model for estimating organic chemical bioconcentration in agricultural plants

    SciTech Connect

    Hung, H.; Mackay, D.; Di Guardo, A.

    1995-12-31

    There is increasing recognition that much human and wildlife exposure to organic contaminants can be traced through the food chain to bioconcentration in vegetation. For risk assessment, there is a need for an accurate model to predict organic chemical concentrations in plants. Existing models range from relatively simple correlations of concentrations using octanol-water or octanol-air partition coefficients, to complex models involving extensive physiological data. To satisfy the need for a relatively accurate model of intermediate complexity, a novel approach has been devised to predict organic chemical concentrations in agricultural plants as a function of soil and air concentrations, without the need for extensive plant physiological data. The plant is treated as three compartments, namely, leaves, roots and stems (including fruit and seeds). Data readily available from the literature, including chemical properties, volume, density and composition of each compartment; metabolic and growth rate of plant; and readily obtainable environmental conditions at the site are required as input. Results calculated from the model are compared with observed and experimentally-determined concentrations. It is suggested that the model, which includes a physiological database for agricultural plants, gives acceptably accurate predictions of chemical partitioning between plants, air and soil.

  5. Evaluation of screening procedures for bioconcentratable organic chemicals in effluents and sediments

    SciTech Connect

    Burkhard, L.P.; Sheedy, B.R.

    1995-04-01

    Screening procedures have been developed by the US Environmental Protection Agency (EPA) to isolate and tentatively identify nonpolar organic chemicals in effluent and sediment samples with high potential to form chemical residues in aquatic organisms. The objective of this study was to determine if the sample components tentatively identified by the effluent- and sediment-screening procedures actually form chemical residues in aquatic organisms. This evaluation consisted of analyzing effluent and sediment samples from a field site with discharges from two coke-manufacturing facilities using the screening procedures. Effluent, sediment, crayfish (Decapoda), and sunfish (Lepomis sp.) samples from the field site were also prepared using conventional sample preparation procedures and analyzed for the tentatively identified chemicals (TIDs) reported by the screening procedures. Results of the screening procedures were then compared to the results of the analyses on the samples prepared using the conventional sample preparation procedures. For the effluent-screening procedure, 182 of 183 TIDs in Coke Plant 1 effluent and all of the 7 TIDs in Coke Plant 2 effluent were found in the crayfish, sunfish, and/or sediment samples downstream of the discharges. For the sediment-screening procedure, 92 of 93 TIDs and all of 47 TIDs in sediment samples from two sampling stations downstream of the discharges were found in the crayfish and/or sunfish samples.

  6. Overview of the ToxCast Research Program: Applications to Predictive Toxicology and Chemical Prioritization (SETAC)

    EPA Science Inventory

    Understanding the potential health risks posed by environmental chemicals is a significant challenge driven by the large number of diverse chemicals with generally uncharacterized exposures, mechanisms and toxicities. The U.S. EPA’s ToxCast chemical prioritization research projec...

  7. Research programs for Division of Chemical Sciences, Office of Basic Energy Sciences, Department of Energy

    SciTech Connect

    Not Available

    1988-01-01

    A chemical sciences review meeting was held in which research programs in chemistry were discussed. Major topics included: chemistry of actinides and fission products, interactions of solvents, solutes and surfaces in supercritical extraction, chemical and physical principles in multiphase separations, and chemical kinetics of enzyme catalyzed reactions. Individual projects are processed separately for the data bases. (CBS)

  8. Feeding trials in organic food quality and health research.

    PubMed

    Velimirov, Alberta; Huber, Machteld; Lauridsen, Charlotte; Rembiałkowska, Ewa; Seidel, Kathrin; Bügel, Susanne

    2010-01-30

    Feeding experiments comparing organically and conventionally produced food are performed to assess the overall impact on the animals' health as a model for the effects experienced by the human consumers. These experiments are based on systems research and characterized by their focus on production methods, whole food testing and procedures in accordance with the terms of organic farming. A short review of such experiments shows that the majority of these tests revealed effects of the organically produced feed on health parameters such as reproductive performance and immune responses. Systems research is not just about simple cause-effect chains, but rather about the pluralism of interactions in biological networks; therefore, the interpretation of the outcome of whole food experiments is difficult. Furthermore, the test diets of organic and conventional origin can be constituted in different ways, compensating for or maintaining existing differences in nutrient and energy contents. The science-based results suggest positive influences from organic feeds, but there is still a need for confirmation in animals and, finally, in humans. For this purpose animal feeding trials with feed from different production systems should be conducted, with the aims to define health indicators and to establish biomarkers as a basis for future dietary intervention studies in humans.

  9. Chemical Identity Crisis: Glass and Glassblowing in the Identification of Organic Compounds.

    PubMed

    Jackson, Catherine M

    2015-04-01

    This essay explains why and how nineteenth-century chemists sought to stabilize the melting and boiling points of organic substances as reliable characteristics of identity and purity and how, by the end of the century, they established these values as 'Constants of Nature'. Melting and boiling points as characteristic values emerge from this study as products of laboratory standardization, developed by chemists in their struggle to classify, understand and control organic nature. A major argument here concerns the role played by the introduction of organic synthesis in driving these changes. Synthetic organic chemistry vastly increased the number of known organic substances, precipitating the chemical identity crisis of my title. Successful natural product synthesis, moreover, depended on chemists' ability to demonstrate the absolute identity of synthetic product and natural target--something late nineteenth-century chemists eventually achieved by making reliable, replicable melting and boiling point measurements. In the period before the establishment of national standards laboratories, chemists and scientific glassblowers worked together to standardize melting and boiling points as physical constants, such collaborations highlighting the essential importance of chemical glassware and glassblowing skill in the development of nineteenth-century organic chemistry.

  10. Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms.

    PubMed

    Repetto, Guillermo; Zurita, Jorge L; Roncel, Mercedes; Ortega, José M

    2015-01-01

    Thermoluminescence is a simple technique very useful for studying electron transfer reactions on photosystem II (standard thermoluminescence) or the level of lipid peroxidation in membranes (high temperature thermoluminescence) in photosynthetic organisms. Both techniques were used to investigate the effects produced on Chlorella vulgaris cells by six compounds: the chemical intermediates bromobenzene and diethanolamine, the antioxidant propyl gallate, the semiconductor indium nitrate, the pesticide sodium monofluoroacetate and the antimalarial drug chloroquine. Electron transfer activity of the photosystem II significantly decreased after the exposure of Chlorella cells to all the six chemicals used. Lipid peroxidation was slightly decreased by the antioxidant propyl gallate, not changed by indium nitrate and very potently stimulated by diethanolamine, chloroquine, sodium monofluoroacetate and bromobenzene. For five of the chemicals studied (not bromobenzene) there is a very good correlation between the cytotoxic effects in Chlorella cells measured by the algal growth inhibition test, and the inhibition of photosystem II activity. The results suggest that one very important effect of these chemicals in Chlorella cells is the inhibition of photosynthetic metabolism by the blocking of photosystem II functionality. In the case of sodium monofluoroacetate, diethanolamine and chloroquine this inhibition seems to be related with the induction of high level of lipid peroxidation in cells that may alter the stability of photosystem II. The results obtained by both techniques supply information that can be used as a supplement to the growth inhibition test and allows a more complete assessment of the effects of a chemical in photosynthetic organisms of aquatic ecosystems.

  11. The Covalent Trimethoprim Chemical Tag Facilitates Single Molecule Imaging with Organic Fluorophores

    PubMed Central

    Wang, Tracy Y.; Friedman, Larry J.; Gelles, Jeff; Min, Wei; Hoskins, Aaron A.; Cornish, Virginia W.

    2014-01-01

    Chemical tags can be used to selectively label proteins with fluorophores that have high photon outputs. By permitting straightforward single molecule (SM) detection and imaging with organic fluorophores, chemical tags have the potential to advance SM imaging as a routine experimental tool for studying biological mechanism. However, there has been little characterization of the photophysical consequences of using chemical tags with organic fluorophores. Here, we examine the effect the covalent trimethoprim chemical tag (A-TMP-tag) has on the SM imaging performance of the fluorophores, Atto655 and Alexa647, by evaluating the photophysical properties of these fluorophores and their A-TMP-tag conjugates. We measure SM photon flux, survival lifetime, and total photon output under conditions that mimic the live cell environment and demonstrate that the A-TMP-tag complements the advantageous SM imaging properties of Atto655 and Alexa647. We also measure the ensemble properties of quantum yield and photostability lifetime, revealing a correlation between SM and ensemble properties. Taken together, these findings establish a systematic method for evaluating the impact chemical tags have on fluorophores for SM imaging and demonstrate that the A-TMP-tag with Atto655 and Alexa647 are promising reagents for biological imaging. PMID:24411259

  12. Differences in chemical composition of soil organic carbon resulting from long-term fertilization strategies.

    PubMed

    Li, Zengqiang; Zhao, Bingzi; Wang, Qingyun; Cao, Xiaoyan; Zhang, Jiabao

    2015-01-01

    Chemical composition of soil organic carbon (SOC) is central to soil fertility. We hypothesize that change in SOC content resulting from various long-term fertilization strategies accompanies the shift in SOC chemical structure. This study examined the effect of fertilization strategies along with the time of fertilizer application on the SOC composition by 13C nuclear magnetic resonance (NMR) spectroscopy. The soils (Aquic Inceptisol) subjected to seven fertilizer treatments were collected in 1989, 1999 and 2009, representing 0, 10 and 20 years of fertilization, respectively. The seven fertilizer treatments were (1-3) balanced fertilization with application of nitrogen (N), phosphorus (P) and potassium (K) including organic compost (OM), half organic compost plus half chemical fertilizer (1/2OM), and pure chemical NPK fertilizer (NPK); (4-6) unbalanced chemical fertilization without application of one of the major elements including NP fertilizer (NP), PK fertilizer (PK), and NK fertilizer (NK); and (7) an unamended control (CK). The SOC content in the balanced fertilization treatments were 2.3-52.6% and 9.4-64.6% higher than in the unbalanced fertilization/CK treatments in 1999 and 2009, respectively, indicating significant differences in SOC content with time of fertilizer application between the two treatment groups. There was a significantly greater proportion of O-alkyl C and a lower proportion of aromatic C in the balanced fertilization than in unbalanced fertilization/CK treatments in 1999, but not in 2009, because their proportions in the former treatments approached the latter in 2009. Principal component analysis further showed that the C functional groups from various fertilization strategies tended to become compositionally similar with time. The results suggest that a shift in SOC chemical composition may be firstly dominated by fertilization strategies, followed by fertilization duration.

  13. Identifying the macromolecular targets of de novo-designed chemical entities through self-organizing map consensus.

    PubMed

    Reker, Daniel; Rodrigues, Tiago; Schneider, Petra; Schneider, Gisbert

    2014-03-18

    De novo molecular design and in silico prediction of polypharmacological profiles are emerging research topics that will profoundly affect the future of drug discovery and chemical biology. The goal is to identify the macromolecular targets of new chemical agents. Although several computational tools for predicting such targets are publicly available, none of these methods was explicitly designed to predict target engagement by de novo-designed molecules. Here we present the development and practical application of a unique technique, self-organizing map-based prediction of drug equivalence relationships (SPiDER), that merges the concepts of self-organizing maps, consensus scoring, and statistical analysis to successfully identify targets for both known drugs and computer-generated molecular scaffolds. We discovered a potential off-target liability of fenofibrate-related compounds, and in a comprehensive prospective application, we identified a multitarget-modulating profile of de novo designed molecules. These results demonstrate that SPiDER may be used to identify innovative compounds in chemical biology and in the early stages of drug discovery, and help investigate the potential side effects of drugs and their repurposing options.

  14. Identifying the macromolecular targets of de novo-designed chemical entities through self-organizing map consensus

    PubMed Central

    Reker, Daniel; Rodrigues, Tiago; Schneider, Petra; Schneider, Gisbert

    2014-01-01

    De novo molecular design and in silico prediction of polypharmacological profiles are emerging research topics that will profoundly affect the future of drug discovery and chemical biology. The goal is to identify the macromolecular targets of new chemical agents. Although several computational tools for predicting such targets are publicly available, none of these methods was explicitly designed to predict target engagement by de novo-designed molecules. Here we present the development and practical application of a unique technique, self-organizing map–based prediction of drug equivalence relationships (SPiDER), that merges the concepts of self-organizing maps, consensus scoring, and statistical analysis to successfully identify targets for both known drugs and computer-generated molecular scaffolds. We discovered a potential off-target liability of fenofibrate-related compounds, and in a comprehensive prospective application, we identified a multitarget-modulating profile of de novo designed molecules. These results demonstrate that SPiDER may be used to identify innovative compounds in chemical biology and in the early stages of drug discovery, and help investigate the potential side effects of drugs and their repurposing options. PMID:24591595

  15. Whole-Organism Concentration Ratios for Plutonium in Wildlife from Past US Nuclear Research Data

    SciTech Connect

    johansen, M.; Kamboj; Kuhne, W.

    2012-07-26

    Whole-organism concentration ratios (CR{sub wo-media}) for plutonium (Pu) in wildlife were calculated using data from the broad range of organism types and environmental settings of the US nuclear research program. Original sources included site-specific reports and scientific journal articles typically from 1960s to 80s research. Most of the calculated CR{sub wo-media} values are new to existing data sets, and, for some wildlife categories, serve to fill gaps or add to sparse data including those for terrestrial reptile; freshwater bird, crustacean and zooplankton; and marine crustacean and zooplankton. Ratios of Pu concentration in the whole-organism to that in specific tissues and organs are provided here for a range of freshwater and marine fish. The CR{sub wo-media} values in fish living in liquid discharge ponds were two orders of magnitude higher than those for similar species living in lakes receiving Pu from atmospheric fallout, suggesting the physico-chemical form of the source Pu can dominate over other factors related to transfer, such as organism size and feeding behavior. Small rodent data indicated one to two order of magnitude increases when carcass, pelt, and gastrointestinal tract were included together in the whole-organism calculation compared to that for carcass alone. Only 4% of Pu resided in the carcass of small rodents compared to 75% in the gastrointestinal tract and 21% in the pelt.

  16. Whole-organism concentration ratios for plutonium in wildlife from past US nuclear research data.

    PubMed

    Johansen, M P; Kamboj, S; Kuhne, W W

    2013-12-01

    Whole-organism concentration ratios (CRwo-media) for plutonium (Pu) in wildlife were calculated using data from the broad range of organism types and environmental settings of the US nuclear research program. Original sources included site-specific reports and scientific journal articles typically from 1960s to 80s research. Most of the calculated CRwo-media values are new to existing data sets, and, for some wildlife categories, serve to fill gaps or add to sparse data including those for terrestrial reptile; freshwater bird, crustacean and zooplankton; and marine crustacean and zooplankton. Ratios of Pu concentration in the whole-organism to that in specific tissues and organs are provided here for a range of freshwater and marine fish. The CRwo-media values in fish living in liquid discharge ponds were two orders of magnitude higher than those for similar species living in lakes receiving Pu from atmospheric fallout, suggesting the physico-chemical form of the source Pu can dominate over other factors related to transfer, such as organism size and feeding behavior. Small rodent data indicated one to two order of magnitude increases when carcass, pelt, and gastrointestinal tract were included together in the whole-organism calculation compared to that for carcass alone. Only 4% of Pu resided in the carcass of small rodents compared to 75% in the gastrointestinal tract and 21% in the pelt.

  17. Direct chemical oxidation: a non-thermal technology for the destruction of organic wastes

    SciTech Connect

    Balazs, G.B.; Cooper, J. F.; Lewis, P. R.; Adamson, M. G.

    1998-02-01

    Direct Chemical Oxidation (DCO) is a non-thermal, ambient pressure, aqueous-based technology for the oxidative destruction of the organic components of hazardous or mixed waste streams. The process has been developed for applications in waste treatment and chemical demilitarization and decontamination at LLNL since 1992, and is applicable to the destruction of virtually all solid or liquid organics, including: chlorosolvents, oils and greases, detergents, organic-contaminated soils or sludges, explosives, chemical and biological warfare agents, and PCB's. [1-15] The process normally operates at 80-100 C, a heating requirement which increases the difficulty of surface decontamination of large objects or, for example, treatment of a wide area contaminated soil site. The driver for DCO work in FY98 was thus to investigate the use of catalysts to demonstrate the effectiveness of the technology for organics destruction at temperatures closer to ambient. In addition, DCO is at a sufficiently mature stage of development that technology transfer to a commercial entity was a logical next step, and was thus included in FY98 tasks.

  18. Research priority setting in organ transplantation: a systematic review.

    PubMed

    Tong, Allison; Sautenet, Benedicte; Chapman, Jeremy R; Harper, Claudia; MacDonald, Peter; Shackel, Nicholas; Crowe, Sally; Hanson, Camilla; Hill, Sophie; Synnot, Anneliese; Craig, Jonathan C

    2017-04-01

    Barriers to access and long-term complications remain a challenge in transplantation. Further advancements may be achieved through research priority setting with patient engagement to strengthen its relevance. We evaluated research priority setting in solid organ transplantation and described stakeholder priorities. Databases were searched to October 2016. We synthesized the findings descriptively. The 28 studies (n = 2071 participants) addressed kidney [9 (32%)], heart [7 (25%)], liver [3 (11%)], lung [1 (4%)], pancreas [1 (4%)], and nonspecified organ transplantation [7 (25%)] using consensus conferences, expert panel meetings, workshops, surveys, focus groups, interviews, and the Delphi technique. Nine (32%) reported patient involvement. The 336 research priorities addressed the following: organ donation [43 priorities (14 studies)]; waitlisting and allocation [43 (10 studies)]; histocompatibility and immunology [31 (8 studies)]; immunosuppression [21 (10 studies)]; graft-related complications [38 (13 studies)]; recipient (non-graft-related) complications [86 (14 studies)]; reproduction [14 (1 study)], psychosocial and lifestyle [49 (7 studies)]; and disparities in access and outcomes [10 (4 studies)]. The priorities identified were broad but only one-third of initiatives engaged patients/caregivers, and details of the process were lacking. Setting research priorities in an explicit manner with patient involvement can guide investment toward the shared priorities of patients and health professionals.

  19. The ethics of pharmaceutical research funding: a social organization approach.

    PubMed

    Gray, Garry C

    2013-01-01

    This paper advances a social organization approach to examining unethical behavior. While unethical behaviors may stem in part from failures in individual morality or psychological blind spots, they are both generated and performed through social interactions among individuals and groups. To illustrate the value of a social organization approach, a case study of a medical school professor's first experience with pharmaceutical-company-sponsored research is provided in order to examine how funding arrangements can constrain research integrity. The case illustrates three significant ways that institutional corruption can occur in the research process. First, conflicts of norms between pharmaceutical companies, universities, and affiliated teaching hospitals can result in compromises and self-censorship. Second, normal behavior is shaped through routine interactions. Unethical behaviors can be (or can become) normal behaviors when they are produced and reproduced through a network of social interactions. Third, funding arrangements can create networks of dependency that structurally distort the independence of the academic researcher in favor of the funder's interests. More broadly, the case study demonstrates how the social organization approach deepens our understanding of the practice of ethics.

  20. Correlation of tissue, blood, and air partition coefficients of volatile organic chemicals.

    PubMed Central

    Paterson, S; Mackay, D

    1989-01-01

    The physical chemical factors controlling partition coefficients between air, water, blood, and various tissues are discussed. It is suggested that improved insights into the relations between partition coefficients, which are frequently expressed as correlations, may be obtained by viewing the partition coefficients as ratios of solubilities or pseudosolubilities. A simple, novel correlation approach is developed and applied to 24 volatile organic chemicals, which enables tissue/blood, tissue/air, and blood/air partition coefficients to be estimated from water solubility and vapour pressure. An illustration is presented in which these solubilities are used to calculate the equilibrium distribution of dichloromethane between air, blood, and various tissues. PMID:2751930

  1. Micro- and Nanostructured Metal Oxide Chemical Sensors for Volatile Organic Compounds

    NASA Technical Reports Server (NTRS)

    Alim, M. A.; Penn, B. G.; Currie, J. R., Jr.; Batra, A. K.; Aggarwal, M. D.

    2008-01-01

    Aeronautic and space applications warrant the development of chemical sensors which operate in a variety of environments. This technical memorandum incorporates various kinds of chemical sensors and ways to improve their performance. The results of exploratory investigation of the binary composite polycrystalline thick-films such as SnO2-WO3, SnO2-In2O3, SnO2-ZnO for the detection of volatile organic compound (isopropanol) are reported. A short review of the present status of the new types of nanostructured sensors such as nanobelts, nanorods, nanotube, etc. based on metal oxides is presented.

  2. Management of the industry/research organization interface

    SciTech Connect

    John, B.; Spiliopoulos, J.M.; Beazley, J.; Harvey, T.J.M.; Gillies, A.D.S.

    1999-07-01

    The purpose of a consultancy undertaken to assess management processes in research projects to improve communication between research organizations and the mining industry through the development of an improved mode of operation and customer interface is discussed. The consultancy was conducted using the Nadler and Tushman Congruency Model of Organizational Behavior to assess components of a project's inputs, transformation process and outputs for their degree of congruence or fit. As an example the University of Queensland (UQ) managed ACARP project Maximizing Coal Production in the Presence of Hydrogen Sulfide (H{sub 2}S) Seam Gas was used for illustration. An action research process was used to collect data on the project organization and history, observations made of group project meetings and interviews undertaken with project staff and representatives of the mining industry and the UQ. The findings highlighted major differences in culture between the university and industry, inadequate planning and strategy development, ineffective inter-group communication, high and conflicting demands on time, and in some cases a poor fit between individuals and tasks. Recommendations proposed to address these issues are presented as two groups, those applicable to the current H{sub 2}S Project and those for future similar research projects. They involve improved strategies for inter-group and interpersonal communication, role clarification, project administration and organizational learning and assessment. The proposed interventions are relatively simple, easily implemented and inexpensive. They have the potential to improve the fit between the components of the organization as well as between the organization and its environment, enhance efficiency and effectiveness and improve the relationship between the university and industry to ensure future collaborative research projects and access to external funding.

  3. Introductory lecture: atmospheric organic aerosols: insights from the combination of measurements and chemical transport models.

    PubMed

    Pandis, Spyros N; Donahue, Neil M; Murphy, Benjamin N; Riipinen, Ilona; Fountoukis, Christos; Karnezi, Eleni; Patoulias, David; Skyllakou, Ksakousti

    2013-01-01

    The formation, atmospheric evolution, properties, and removal of organic particulate matter remain some of the least understood aspects of atmospheric chemistry despite the importance of organic aerosol (OA) for both human health and climate change. Here, we summarize our recent efforts to deal with the chemical complexity of the tens of thousands of organic compounds in the atmosphere using the volatility-oxygen content framework (often called the 2D-Volatility Basis Set, 2D-VBS). Our current ability to measure the ambient OA concentration as a function of its volatility and oxygen to carbon (O:C) ratio is evaluated. The combination of a thermodenuder, isothermal dilution and Aerosol Mass Spectrometry (AMS) together with a mathematical aerosol dynamics model is a promising approach. The development of computational modules based on the 2D-VBS that can be used in chemical transport models (CTMs) is described. Approaches of different complexity are tested against ambient observations, showing the challenge of simulating the complex chemical evolution of atmospheric OA. The results of the simplest approach describing the net change due to functionalization and fragmentation are quite encouraging, reproducing both the observed OA levels and O : C in a variety of conditions. The same CTM coupled with source-apportionment algorithms can be used to gain insights into the travel distances and age of atmospheric OA. We estimate that the average age of OA near the ground in continental locations is 1-2 days and most of it was emitted (either as precursor vapors or particles) hundreds of kilometers away. Condensation of organic vapors on fresh particles is critical for the growth of these new particles to larger sizes and eventually to cloud condensation nuclei (CCN) sizes. The semivolatile organics currently simulated by CTMs are too volatile to condense on these tiny particles with high curvature. We show that chemical aging reactions converting these semivolatile

  4. Low-level chemical sensitivity: implications for research and social policy.

    PubMed

    Ashford, N A

    1999-01-01

    There is increasing evidence that human exposure to levels of chemicals once thought to be safe--or presenting insignificant risk--are, in fact, harmful. So-called low-level exposures are now known to be associated with adverse biological effects including cancer, endocrine disruption, and chemical sensitivity. This requires that we change both (1) the way we design research linking chemicals and health, and (2) the solutions we devise to address chemically caused injury. The new and emerging science of low-level exposure to chemicals requires appropriate social policy responses which include regulation of toxic substances, notification of those exposed, and compensation and reasonable accommodation to those affected. Research and social policy need to be focused towards two distinct groups: (1) those individuals who could become chemically intolerant as a result of an initiating exposure, and (2) those individuals who have already become chemically intolerant and are now sensitive to chemicals at low levels.

  5. Education Finance and Organization: Research Perspectives for the Future. Program on Educational Policy and Organization.

    ERIC Educational Resources Information Center

    Benson, Charles S., Comp.; And Others

    The Stanford-Berkeley Seminar on School Finance and Organization was convened to reexamine the problems that underlay the educational finance reform movement, to consider the new problems caused by that movement, and to recommend research topics and study areas that could help alleviate those problems in years to come. The eight papers discussed…

  6. Current knowledge and future research perspectives on cassava (Manihot esculenta Crantz) chemical defenses: An agroecological view.

    PubMed

    Pinto-Zevallos, Delia M; Pareja, Martín; Ambrogi, Bianca G

    2016-10-01

    Cassava (Manihot esculenta Crantz) is one of the most important staple crops worldwide. It constitutes the major source of carbohydrates for millions of low-income people living in rural areas, as well as a cash crop for smallholders in tropical and sub-tropical regions. The Food and Agriculture Organization of the United Nations predicts that cassava plantations will increase and production systems will intensify in the future, highlighting the need for developing strategies that improve the sustainability of production. Plant chemical defenses hold the potential for developing pest management strategies, as these plant traits can influence the behavior and performance of both pests and beneficial arthropods. Cassava plants are well-defended and produce a number of compounds involved in direct defense, such as cyanogenic glycosides, flavonoid glycosides, and hydroxycoumarins. In addition, volatile organic compounds induced upon herbivory and the secretion of extrafloral nectar act as indirect defense against herbivores by recruiting natural enemies. Here, cassava chemical defenses against pest arthropods are reviewed, with the aim of identifying gaps in our knowledge and areas of research that deserve further investigation for developing sound pest control strategies to improve sustainable production of this crop, and how these defenses can be used to benefit other crops. Cyanogenic content in cassava is also highly toxic to humans, and can cause irreversible health problems even at sub-lethal doses when consumed over prolonged periods. Therefore, the promotion of chemical defense in this crop should not aggravate these problems, and must be accompanied with the education on processing methods that reduce human exposure to cyanide.

  7. Bridging epidemiology and model organisms to increase understanding of endocrine disrupting chemicals and human health effects.

    PubMed

    Woodruff, Tracey J

    2011-10-01

    Concerning temporal trends in human reproductive health has prompted concern about the role of environmentally mediated risk factors. The population is exposed to chemicals present in air, water, food and in a variety of consumer and personal care products, subsequently multiple chemicals are found human populations around the globe. Recent reviews find that endocrine disrupting chemicals (EDCs) can adversely affect reproductive and developmental health. However, there are still many knowledge gaps. This paper reviews some of the key scientific concepts relevant to integrating information from human epidemiologic and model organisms to understand the relationship between EDC exposure and adverse human health effects. Additionally, areas of new insights which influence the interpretation of the science are briefly reviewed, including: enhanced understanding of toxicity pathways; importance of timing of exposure; contribution of multiple chemical exposures; and low dose effects. Two cases are presented, thyroid disrupting chemicals and anti-androgens chemicals, which illustrate how our knowledge of the relationship between EDCs and adverse human health effects is strengthened and data gaps reduced when we integrate findings from animal and human studies.

  8. In vivo covalent binding of organic chemicals to DNA as a quantitative indicator in the process of chemical carcinogenesis.

    PubMed

    Lutz, W K

    1979-12-01

    The covalent binding of chemical carcinogens to DNA of mammalian organs is expressed per unit dose, and a 'Covalent-Binding Index', CBI, is defined. CBI for various carcinogens span over 6 orders of magnitude. A similar range is observed for the carcinogenic potency in long-term bioassays on carcinogenicity. For the assessment of a risk from exposure to a carcinogen, the total DNA dmaage can be estimated if the actual dose is also accounted for. A detailed description is given for planning and performing a DNA-binding assay. A complete literature survey on DNA binding in vivo (83 compounds) is given with a calculation of CBI, where possible, 153 compounds are listed where a covalent binding to any biological macromolecule has been shown in vivo or in vitro. Recent, so far unpublished findings with aflatoxin M1, macromolecule-bound aflatoxin B1, diethylstilbestrol, and 1,2-epithiobutyronitrile are included. A comparison of CBI for rat-liver DNA with hepatocarcinogenic potency reveals a surprisingly good quantitative correlation. Refinements for a DNA-binding assay are proposed. Possibilites and limitations in the use of DNA binding in chemical carcinogenesis are discussed extensively.

  9. A Research Module for the Organic Chemistry Laboratory: Multistep Synthesis of a Fluorous Dye Molecule

    PubMed Central

    2014-01-01

    A multi-session research-like module has been developed for use in the undergraduate organic teaching laboratory curriculum. Students are tasked with planning and executing the synthesis of a novel fluorous dye molecule and using it to explore a fluorous affinity chromatography separation technique, which is the first implementation of this technique in a teaching laboratory. Key elements of the project include gradually introducing students to the use of the chemical literature to facilitate their searching, as well as deliberate constraints designed to force them to think critically about reaction design and optimization in organic chemistry. The project also introduces students to some advanced laboratory practices such as Schlenk techniques, degassing of reaction mixtures, affinity chromatography, and microwave-assisted chemistry. This provides students a teaching laboratory experience that closely mirrors authentic synthetic organic chemistry practice in laboratories throughout the world. PMID:24501431

  10. A Research Module for the Organic Chemistry Laboratory: Multistep Synthesis of a Fluorous Dye Molecule.

    PubMed

    Slade, Michael C; Raker, Jeffrey R; Kobilka, Brandon; Pohl, Nicola L B

    2014-01-14

    A multi-session research-like module has been developed for use in the undergraduate organic teaching laboratory curriculum. Students are tasked with planning and executing the synthesis of a novel fluorous dye molecule and using it to explore a fluorous affinity chromatography separation technique, which is the first implementation of this technique in a teaching laboratory. Key elements of the project include gradually introducing students to the use of the chemical literature to facilitate their searching, as well as deliberate constraints designed to force them to think critically about reaction design and optimization in organic chemistry. The project also introduces students to some advanced laboratory practices such as Schlenk techniques, degassing of reaction mixtures, affinity chromatography, and microwave-assisted chemistry. This provides students a teaching laboratory experience that closely mirrors authentic synthetic organic chemistry practice in laboratories throughout the world.

  11. Chemical and biological sensors based on organic thin-film transistors.

    PubMed

    Mabeck, Jeffrey T; Malliaras, George G

    2006-01-01

    The application of organic thin-film transistors (OTFTs) to chemical and biological sensing is reviewed. This review covers transistors that are based on the modulation of current through thin organic semiconducting films, and includes both field-effect and electrochemical transistors. The advantages of using OTFTs as sensors (including high sensitivity and selectivity) are described, and results are presented for sensing analytes in both gaseous and aqueous environments. The primary emphasis is on the major developments in the field of OTFT sensing over the last 5-10 years, but some earlier work is discussed briefly to provide a foundation.

  12. The Meta-Organization: A Research and Conceptual Landscape

    DTIC Science & Technology

    2011-06-01

    DRDC Corporate Paul Chouinard DRDC Centre for Security Science Defence R& D Canada – Centre for Security Science DRDC CSS TR 2011-13 July...Verdun DRDC Corporate Paul Chouinard DRDC Centre for Security Science Defence R& D Canada – CSS Technical Report DRDC CSS TR 2011...Organization: A Research and Conceptual Landscape Alan Okros; John Verdun; Paul Chouinard; DRDC CSS TR 2011-13; Defence R& D Canada – CSS; June 2011

  13. Self-Organization of Water-Organic Systems in Bone Tissue and Products of Its Chemical Degradation

    NASA Astrophysics Data System (ADS)

    Turov, V. V.; Gun'ko, V. M.; Nechypor, O. V.; Golovan, A. P.; Kaspersky, V. A.; Turov, A. V.; Leboda, R.; Jablonski, M.; Gorbyk, P. P.

    Hydration of bone tissue and products of its thermal and chemical degradation in the presence of organic solvents was studied using low-temperature 1H NMR spectroscopy and cryoporometry. It was revealed that water filling nanosized cavities between structural elements of bone tissue can be assigned to two types of clustered structures corresponding to strongly and weakly associated water reflecting in the 1H NMR spectra as separate signals with chemical shift δ H = 1.3 and 5 ppm. It was shown that the chloroform medium stabilizes weakly associated water and reduces interaction of strongly associated water with the phase boundaries. The same tendency is outlined in protein and mineral components of bovine bone. The presence of electron-donor solvents (acetonitrile, DMSO) leads to formation of clustered structures (with electron-donor molecules, strongly associated water or water solution in organic solvents) in the hydrate shells of structural elements of bone materials. In contrast to the native bone material, individual model systems with proteins or mineral components are characterized by a considerable diminution or complete disappearance of weakly associated water.

  14. Sample preparation of organic liquid for off-site analysis of chemical weapons convention related compounds.

    PubMed

    Pardasani, Deepak; Palit, Meehir; Gupta, A K; Shakya, Purushottam; Sekhar, K; Dubey, D K

    2005-02-15

    Off-site analysis of chemical warfare agents (CWAs) and related compounds plays a key role in the verification program of the Chemical Weapons Convention (CWC). The analysis results, aiming toward unambiguous identication of compounds, depend on the type of sample preparation method. Development of milder sample preparation methods, which offer good recoveries and do not alter the structure of analytes, is highly desirable. Organic liquid with high hydrocarbon background is a frequently encountered challenge in off-site analysis and in official proficiency tests conducted by OPCW. Sample cleanup procedures, namely, solvent exchange followed by cooling and liquid-liquid extraction were studied to eliminate the hydrocarbons from organic liquid. Acetonitrile, a polar aprotic solvent, was effectively used to remove the background in both methods, and recoveries of spiked CWAs by the two techniques were between 69 and 99%.

  15. A chemodynamic approach for estimating losses of target organic chemicals from water during sample holding time

    USGS Publications Warehouse

    Capel, P.D.; Larson, S.J.

    1995-01-01

    Minimizing the loss of target organic chemicals from environmental water samples between the time of sample collection and isolation is important to the integrity of an investigation. During this sample holding time, there is a potential for analyte loss through volatilization from the water to the headspace, sorption to the walls and cap of the sample bottle; and transformation through biotic and/or abiotic reactions. This paper presents a chemodynamic-based, generalized approach to estimate the most probable loss processes for individual target organic chemicals. The basic premise is that the investigator must know which loss process(es) are important for a particular analyte, based on its chemodynamic properties, when choosing the appropriate method(s) to prevent loss.

  16. Relationship between chemical structure and the occupational asthma hazard of low molecular weight organic compounds

    PubMed Central

    Jarvis, J; Seed, M; Elton, R; Sawyer, L; Agius, R

    2005-01-01

    Aims: To investigate quantitatively, relationships between chemical structure and reported occupational asthma hazard for low molecular weight (LMW) organic compounds; to develop and validate a model linking asthma hazard with chemical substructure; and to generate mechanistic hypotheses that might explain the relationships. Methods: A learning dataset used 78 LMW chemical asthmagens reported in the literature before 1995, and 301 control compounds with recognised occupational exposures and hazards other than respiratory sensitisation. The chemical structures of the asthmagens and control compounds were characterised by the presence of chemical substructure fragments. Odds ratios were calculated for these fragments to determine which were associated with a likelihood of being reported as an occupational asthmagen. Logistic regression modelling was used to identify the independent contribution of these substructures. A post-1995 set of 21 asthmagens and 77 controls were selected to externally validate the model. Results: Nitrogen or oxygen containing functional groups such as isocyanate, amine, acid anhydride, and carbonyl were associated with an occupational asthma hazard, particularly when the functional group was present twice or more in the same molecule. A logistic regression model using only statistically significant independent variables for occupational asthma hazard correctly assigned 90% of the model development set. The external validation showed a sensitivity of 86% and specificity of 99%. Conclusions: Although a wide variety of chemical structures are associated with occupational asthma, bifunctional reactivity is strongly associated with occupational asthma hazard across a range of chemical substructures. This suggests that chemical cross-linking is an important molecular mechanism leading to the development of occupational asthma. The logistic regression model is freely available on the internet and may offer a useful but inexpensive adjunct to the

  17. Effects of Organic Matter Heterogeneity on Sorption and Desorption of Hydrophobic Organic Chemicals (HOCs) by Pakokee Peat Soil

    SciTech Connect

    Huang, Weilin; Yu, Zhiqiang; Song, Jianzhing; Peng, Pingan

    2004-03-31

    Previous studies have shown that isotherm nonlinearity, varied sorption capacity and sorption-desorption hystersis relate primarily to the heterogeneity of soil organic matter (SOM). A comprehensive wet chemical isolation procedure was used to isolate and quantify into four fractions from Pahokee peat soil: (1) demineralized pahokee peat soil, (2) humic acids + kerogen + BC (HKB), (3) kerogen and (4) humic acid (HA). The major physical and chemical properties of each fraction were characterized using different techniques, such as Scanning Electron Microscopy, 13C-Nuclear Magnetic Resonance Spectroscopy, etc. The impact of SOM heterogeneity on sorption and desorption equilibria by isolated fractions and original soil was conducted using phenanthrene, naphthalene, 1,2-dichlorobenzene and 1,3,5-trichlorobenzene as sorbates. The data indicated that isolated HKB and kerogen fractions exhibit more nonlinear isotherms, greater sorption capacities and desorption hysteresis than that of HA and their original soil. The role of HA to the overall sorption by soil is less significant compared to HKB and kerogen. The sorption capacity and nonlinearity of demineralized Pahokee Peat soil is greater than original soil which suggested that SOM particle may enwrap up by the inorganic and clay materials, therefore sorbate molecules are not accessible to the surface of SOM particle. The results suggested that kerogen and BC may dominate the overall nonlinear sorption by soil and sediments. The contribution of HA in the overall sorption is different from previous studies. It may be caused by different chemical isolation procedures and needs further investigation.

  18. [Discussion on the model organism in acupuncture and meridians researches].

    PubMed

    Zhang, Wei-bo; Wang, Guang-jun; Tian, Yu-ying; Jia, Shu-yong; Yun, Jie

    2014-12-01

    Using model organism to replace human subjects for experimental objects is an important part in basic research on acupuncture therapy. In the process of experimental research, the first thing is that if the animal model is suitable for revealing the underlying mechanism of acupuncture intervention, if it is relatively close to structures of the human body. In addition, some factors such as being easy to feed, larger in the volume and body-surface, lesser in fur, stable in the germline and reasonable in the cost should be considered. In current acupuncture study, most experiments were carried out in mice and rats, some were conducted in rabbits and cats, fewer conducted in larger animals like mini-pigs and monkeys. Due to being smaller in both body size and superficial area in the mouse and rat, soft and comate skin in the rabbit and cat, difficult breeding for cattle and horse, experimental studies of acupuncture-meridians are in fact not ideal in these animals. Mini-pig has a larger body size and body surface, being similar to the human body in the skin structure and easy to breed, and the monkey is mostly close to the human in the gene and body size, and is thus an ideal model organism for acupuncture research. Because acupoint and meridians have their space specificity, the usage of larger animal as the model organism is necessary.

  19. Textile/metal-organic-framework composites as self-detoxifying filters for chemical-warfare agents.

    PubMed

    López-Maya, Elena; Montoro, Carmen; Rodríguez-Albelo, L Marleny; Aznar Cervantes, Salvador D; Lozano-Pérez, A Abel; Cenís, José Luis; Barea, Elisa; Navarro, Jorge A R

    2015-06-01

    The current technology of air-filtration materials for protection against highly toxic chemicals, that is, chemical-warfare agents, is mainly based on the broad and effective adsorptive properties of hydrophobic activated carbons. However, adsorption does not prevent these materials from behaving as secondary emitters once they are contaminated. Thus, the development of efficient self-cleaning filters is of high interest. Herein, we report how we can take advantage of the improved phosphotriesterase catalytic activity of lithium alkoxide doped zirconium(IV) metal-organic framework (MOF) materials to develop advanced self-detoxifying adsorbents of chemical-warfare agents containing hydrolysable P-F, P-O, and C-Cl bonds. Moreover, we also show that it is possible to integrate these materials onto textiles, thereby combining air-permeation properties of the textiles with the self-detoxifying properties of the MOF material.

  20. GaN Stress Evolution During Metal-Organic Chemical Vapor Deposition

    SciTech Connect

    Amano, H.; Chason, E.; Figiel, J.; Floro, J.A.; Han, J.; Hearne, S.; Hunter, J.; Tsong, I.

    1998-10-14

    The evolution of stress in gallium nitride films on sapphire has been measured in real- time during metal organic chemical vapor deposition. In spite of the 161%0 compressive lattice mismatch of GaN to sapphire, we find that GaN consistently grows in tension at 1050"C. Furthermore, in-situ stress monitoring indicates that there is no measurable relaxation of the tensile growth stress during annealing or thermal cycling.

  1. Self-organization of grafted polyelectrolyte layers via the coupling of chemical equilibrium and physical interactions.

    PubMed

    Tagliazucchi, Mario; de la Cruz, Mónica Olvera; Szleifer, Igal

    2010-03-23

    The competition between chemical equilibrium, for example protonation, and physical interactions determines the molecular organization and functionality of biological and synthetic systems. Charge regulation by displacement of acid-base equilibrium induced by changes in the local environment provides a feedback mechanism that controls the balance between electrostatic, van der Waals, steric interactions and molecular organization. Which strategies do responsive systems follow to globally optimize chemical equilibrium and physical interactions? We address this question by theoretically studying model layers of end-grafted polyacids. These layers spontaneously form self-assembled aggregates, presenting domains of controlled local pH and whose morphologies can be manipulated by the composition of the solution in contact with the film. Charge regulation stabilizes micellar domains over a wide range of pH by reducing the local charge in the aggregate at the cost of chemical free energy and gaining in hydrophobic interactions. This balance determines the boundaries between different aggregate morphologies. We show that a qualitatively new form of organization arises from the coupling between physical interactions and protonation equilibrium. This optimization strategy presents itself with polyelectrolytes coexisting in two different and well-defined protonation states. Our results underline the need of considering the coupling between chemical equilibrium and physical interactions due to their highly nonadditive behavior. The predictions provide guidelines for the creation of responsive polymer layers presenting self-organized patterns with functional properties and they give insights for the understanding of competing interactions in highly inhomogeneous and constrained environments such as those relevant in nanotechnology and those responsible for biological cells function.

  2. Real-time monitoring of volatile organic compounds using chemical ionization mass spectrometry

    DOEpatents

    Mowry, Curtis Dale; Thornberg, Steven Michael

    1999-01-01

    A system for on-line quantitative monitoring of volatile organic compounds (VOCs) includes pressure reduction means for carrying a gaseous sample from a first location to a measuring input location maintained at a low pressure, the system utilizing active feedback to keep both the vapor flow and pressure to a chemical ionization mode mass spectrometer constant. A multiple input manifold for VOC and gas distribution permits a combination of calibration gases or samples to be applied to the spectrometer.

  3. All-organic microelectromechanical systems integrating specific molecular recognition--a new generation of chemical sensors.

    PubMed

    Ayela, Cédric; Dubourg, Georges; Pellet, Claude; Haupt, Karsten

    2014-09-03

    Cantilever-type all-organic microelectromechanical systems based on molecularly imprinted polymers for specific analyte recognition are used as chemical sensors. They are produced by a simple spray-coating-shadow-masking process. Analyte binding to the cantilever generates a measurable change in its resonance frequency. This allows label-free detection by direct mass sensing of low-molecular-weight analytes at nanomolar concentrations.

  4. High index of refraction films for dielectric mirrors prepared by metal-organic chemical vapor deposition

    SciTech Connect

    Brusasco, R.M.

    1989-01-01

    A wide variety of metal oxides with high index of refraction can be prepared by Metal-Organic Chemical Vapor Deposition. We present some recent optical and laser damage results on oxide films prepared by MOCVD which could be used in a multilayer structure for highly reflecting (HR) dielectric mirror applications. The method of preparation affects both optical properties and laser damage threshold. 10 refs., 8 figs., 4 tabs.

  5. Survey of the Anaerobic Biodegradation Potential of Organic Chemicals in Digesting Sludge

    PubMed Central

    Battersby, Nigel S.; Wilson, Valerie

    1989-01-01

    The degradation potential of 77 organic chemicals under methanogenic conditions was examined with an anaerobic digesting sludge from the United Kingdom. Degradation was assessed in terms of net total gas (CH4 plus CO2) produced, expressed as a percentage of the theoretical production (ThGP). The compounds tested were selected from various chemical groups and included substituted phenols and benzoates, pesticides, phthalic acid esters, homocyclic and heterocyclic ring compounds, glycols, and monosubstituted benzenes. The results obtained were in good agreement with published surveys of biodegradability in U.S. digesting sludges and other methanogenic environments. In general, the presence of chloro or nitro groups inhibited anaerobic gas production, while carboxyl and hydroxyl groups facilitated biodegradation. The relationship between substituent position and susceptibility to methanogenic degradation was compound dependent. The following chemicals were completely degraded (≥80% ThGP) at a concentration of 50 mg of carbon per liter: phenol, 2-aminophenol, 4-cresol, catechol, sodium benzoate, 4-aminobenzoic acid, 3-chlorobenzoic acid, phthalic acid, ethylene glycol, diethylene glycol, triethylene glycol, sodium stearate, and quinoline. 3-Cresol, 4-chlorobenzoic acid, dimethyl phthalate, and pyridine were partially degraded. Although the remaining chemicals tested were either persistent or toxic, their behavior may differ at more environmentally realistic chemical-to-biomass ratios. Our findings suggest that biodegradability assessments made with sludge from one source can be extrapolated to sludge from another source with a reasonable degree of confidence and should help in predicting the fate of an organic chemical during the anaerobic digestion of sewage sludge. PMID:16347851

  6. Organization of early frog embryos by chemical waves emanating from centrosomes

    PubMed Central

    Ishihara, Keisuke; Nguyen, Phuong A.; Wühr, Martin; Groen, Aaron C.; Field, Christine M.; Mitchison, Timothy J.

    2014-01-01

    The large cells in early vertebrate development face an extreme physical challenge in organizing their cytoplasm. For example, amphibian embryos have to divide cytoplasm that spans hundreds of micrometres every 30 min according to a precise geometry, a remarkable accomplishment given the extreme difference between molecular and cellular scales in this system. How do the biochemical reactions occurring at the molecular scale lead to this emergent behaviour of the cell as a whole? Based on recent findings, we propose that the centrosome plays a crucial role by initiating two autocatalytic reactions that travel across the large cytoplasm as chemical waves. Waves of mitotic entry and exit propagate out from centrosomes using the Cdk1 oscillator to coordinate the timing of cell division. Waves of microtubule-stimulated microtubule nucleation propagate out to assemble large asters that position spindles for the following mitosis and establish cleavage plane geometry. By initiating these chemical waves, the centrosome rapidly organizes the large cytoplasm during the short embryonic cell cycle, which would be impossible using more conventional mechanisms such as diffusion or nucleation by structural templating. Large embryo cells provide valuable insights to how cells control chemical waves, which may be a general principle for cytoplasmic organization. PMID:25047608

  7. Significance of xenobiotic metabolism for bioaccumulation kinetics of organic chemicals in Gammarus pulex.

    PubMed

    Ashauer, Roman; Hintermeister, Anita; O'Connor, Isabel; Elumelu, Maline; Hollender, Juliane; Escher, Beate I

    2012-03-20

    Bioaccumulation and biotransformation are key toxicokinetic processes that modify toxicity of chemicals and sensitivity of organisms. Bioaccumulation kinetics vary greatly among organisms and chemicals; thus, we investigated the influence of biotransformation kinetics on bioaccumulation in a model aquatic invertebrate using fifteen (14)C-labeled organic xenobiotics from diverse chemical classes and physicochemical properties (1,2,3-trichlorobenzene, imidacloprid, 4,6-dinitro-o-cresol, ethylacrylate, malathion, chlorpyrifos, aldicarb, carbofuran, carbaryl, 2,4-dichlorophenol, 2,4,5-trichlorophenol, pentachlorophenol, 4-nitrobenzyl-chloride, 2,4-dichloroaniline, and sea-nine (4,5-dichloro-2-octyl-3-isothiazolone)). We detected and identified metabolites using HPLC with UV and radio-detection as well as high resolution mass spectrometry (LTQ-Orbitrap). Kinetics of uptake, biotransformation, and elimination of parent compounds and metabolites were modeled with a first-order one-compartment model. Bioaccumulation factors were calculated for parent compounds and metabolite enrichment factors for metabolites. Out of 19 detected metabolites, we identified seven by standards or accurate mass measurements and two via pathway analysis and analogies to other compounds. 1,2,3-Trichlorobenzene, imidacloprid, and 4,6-dinitro-o-cresol were not biotransformed. Dietary uptake contributed little to overall uptake. Differentiation between parent and metabolites increased accuracy of bioaccumulation parameters compared to total (14)C measurements. Biotransformation dominated toxicokinetics and strongly affected internal concentrations of parent compounds and metabolites. Many metabolites reached higher internal concentrations than their parents, characterized by large metabolite enrichment factors.

  8. Effects of Chemical Aging on Global Secondary Organic Aerosol using the Volatility Basis Set Approach

    NASA Astrophysics Data System (ADS)

    Park, R.; Jo, D.; Kim, M.; Spracklen, D. V.; Hodzic, A.

    2014-12-01

    Organic aerosol (OA) constitutes significant mass fractions (20-90%) of total dry fine aerosols in the atmosphere. However, global models of OA have shown large discrepancies when compared to the observations because of the limited capability to simulate secondary OA (SOA). For reducing the discrepancies between observations and models, recent studies have shown that chemical aging reactions in the atmosphere are important because they can lead to decreases in organic volatility, resulting in increase of SOA mass yields. To efficiently simulate chemical aging of SOA in the atmosphere, we implemented the volatility basis set approach in a global 3-D chemical transport model (GEOS-Chem). We present full-year simulations and their comparisons with multiple observations - global aerosol mass spectrometer dataset, the Interagency Monitoring of Protected Visual Environments from the United States, the European Monitoring and Evaluation Programme dataset and water-soluble organic carbon observation data collected over East Asia. Using different input parameters in the model, we also explore the uncertainty of the SOA simulation for which we use an observational constraint to find the optimized values with which the model reduces the discrepancy from the observations. Finally, we estimate the effect of OA on climate using our best simulation results.

  9. Chemical Characterization of the Soil Organic Matter in the Atacama Desert, Chile

    NASA Astrophysics Data System (ADS)

    Iñiguez, E.; Navarro-González, R.; Miranda, L. D.; McKay, C.

    2005-12-01

    The arid core region of the Atacama Desert located in Yungay, Chile contains Mars-like soils that have undetectable bacterial populations, low organic concentrations, and the presence of a non-chirally specific oxidant (Navarro-Gonzalez, et al., 2003, Science 302, 1018-1021). The level of organics in these soils would be undetectable by pyr-GC-MS at Viking temperatures (200-500°C) but detectable at higher temperatures (750°C). The chemical characterization of organics in these soils is relevant for the development of new methodologies for the search of organics in the Martian surface. Consequently we have extracted the organics from the soil matrix using organic solvents in a Soxhlet apparatus, and analyzed the dry residue by different analytical techniques such as 1H-NMR, FTIR, GC-MS, and pyr-GC-MS. Our preliminary results indicate that the organics present in the soil of the core region of the Atacama Desert are composed of polycyclic aromatic hydrocarbons, cyclic aliphatic chains, and different carboxylic and amino groups.

  10. Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: October-December 1997

    SciTech Connect

    Jubin, R.T.

    1999-02-01

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period October--December 1997. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within six major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information. Activities conducted within the area of Hot Cell Operations included efforts to optimize the processing conditions for Enhanced Sludge Washing of Hanford tank sludge, the testing of candidate absorbers and ion exchangers under continuous-flow conditions using actual supernatant from the Melton Valley Storage Tanks, and attempts to develop a cesium-specific spherical inorganic sorbent for the treatment of acidic high-salt waste solutions. Within the area of Process Chemistry and Thermodynamics, the problem of solids formation in process solutions from caustic treatment of Hanford sludge was addressed and experimental collaborative efforts with Russian scientists to determine the solidification conditions of yttrium barium, and copper oxides from their melts were completed.

  11. Research on the Reproductive Effects of Endocrine Disrupting Chemicals

    EPA Pesticide Factsheets

    Reproductive hormones exert their effects at many life stages. During embryo and fetus development in the womb, these hormones direct formation of sex organs and the cells that give rise to sperm and eggs.

  12. Chemical Mapping of Proterozoic Organic Matter at Sub-Micron Spatial Resolution

    NASA Technical Reports Server (NTRS)

    Oehler, Dorothy Z.; Robert, Francois; Mostefaoui, Smail; Meibom, Anders; Selo, Madeleine; McKay, David S.

    2006-01-01

    We have used a NanoSIMS ion microprobe to map sub-micron-scale distributions of carbon, nitrogen, sulfur, silicon, and oxygen in organic microfossils and laminae from the approximately 0.85 Ga Bitter Springs Formation of Australia. The data provide clues about the original chemistry of the microfossils, the silicification process, and biosignatures of specific microorganisms and microbial communities. Chemical maps of fossil unicells and filaments reveal distinct wall-and sheath-like structures enriched in C, N and S, consistent with their accepted biological origin. Surprisingly, organic laminae, previously considered to be amorphous, also exhibit filamentous and apparently compressed spheroidal structures defined by strong enrichments in C, N and S. By analogy to data from the well-preserved microfossils, these structures are interpreted as being of biological origin, most likely representing densely packed remnants of microbial mats. Because the preponderance of organic matter in Precambrian sediments is similarly "amorphous," our findings open a large body of generally neglected material to in situ structural, chemical, and isotopic study. Our results also offer new criteria for assessing biogenicity of problematic kerogenous materials and thus can be applied to assessments of poorly preserved or fragmentary organic residues in early Archean sediments and any that might occur in meteorites or other extraterrestrial samples.

  13. Uptake of Organic Vapors by Sulfate Aerosols: Physical and Chemical Processes

    NASA Technical Reports Server (NTRS)

    Michelsen, R. R.; Ashbourn, S. F. M.; Iraci, L.T.; Staton, S. J. R.

    2003-01-01

    While it is known that upper tropospheric sulfate particles contain a significant amount of organic matter, both the source of the organic fraction and its form in solution are unknown. These studies explore how the chemical characteristics of the molecules and surfaces in question affect heterogeneous interactions. The solubilities of acetaldehyde [CH3CHO] and ethanol [CH3CH20H] in cold, aqueous sulfuric acid solutions have been measured by Knudsen cell studies. Henry's law solubility coefficients range from 10(exp 2) to 10(exp 5) M/atm for acetaldehyde, and from 10(exp 4) to 10(exp 9) M/atm for ethanol under upper tropospheric conditions (210-240 K, 40-80 wt. % H2S04). The multiple solvation pathways (protonation, enolization, etc.) available to these compounds in acidic aqueous environments will be discussed. Preliminary results from the interaction of acetaldehyde with solutions of formaldehyde in sulfuric acid will be presented as well. The physical and chemical processes that affect organic uptake by aqueous aerosols will be explored, with the aim of evaluating organic species not yet studied in low temperature aqueous sulfuric acid.

  14. Chemical insights, explicit chemistry and yields of secondary organic aerosol from methylglyoxal and glyoxal

    NASA Astrophysics Data System (ADS)

    Lim, Y. B.; Tan, Y.; Turpin, B. J.

    2013-02-01

    Atmospherically abundant, volatile water soluble organic compounds formed through gas phase chemistry (e.g., glyoxal (C2), methylglyoxal (C3) and acetic acid) have great potential to form secondary organic aerosol (SOA) via aqueous chemistry in clouds, fogs and wet aerosols. This paper (1) provides chemical insights into aqueous-phase OH radical-initiated reactions leading to SOA formation from methylglyoxal and (2) uses this and a previously published glyoxal mechanism (Lim et al., 2010) to provide SOA yields for use in chemical transport models. Detailed reaction mechanisms including peroxy radical chemistry and a full kinetic model for aqueous photochemistry of acetic acid and methylglyoxal are developed and validated by comparing simulations with the experimental results from previous studies (Tan et al., 2010, 2012). This new methylglyoxal model is then combined with the previous glyoxal model (Lim et al., 2010), and is used to simulate the profiles of products and to estimate SOA yields. At cloud relevant concentrations (∼ 10-6-∼ 10-3 M; Munger et al., 1995) of glyoxal and methylglyoxal, the major photooxidation products are oxalic acid and pyruvic acid, and simulated SOA yields (by mass) are ∼ 120% for glyoxal and ∼ 80% for methylglyoxal. Oligomerization of unreacted aldehydes during droplet evaporation could enhance yields. In wet aerosols, where total dissolved organics are present at much higher concentrations (∼ 10 M), the major products are oligomers formed via organic radical-radical reactions, and simulated SOA yields (by mass) are ∼ 90% for both glyoxal and methylglyoxal.

  15. Nanoscale organic and polymeric field-effect transistors as chemical sensors.

    PubMed

    Wang, Liang; Fine, Daniel; Sharma, Deepak; Torsi, Luisa; Dodabalapur, Ananth

    2006-01-01

    This article reviews recently published work concerning improved understanding of, and advancements in, organic and polymer semiconductor vapor-phase chemical sensing. Thin-film transistor sensors ranging in size from hundreds of microns down to a few nanometers are discussed, with comparisons made of sensing responses recorded at these different channel-length scales. The vapor-sensing behavior of nanoscale organic transistors is different from that of large-scale devices, because electrical transport in a nanoscale organic thin-film transistor depends on its morphological structure and interface properties (for example injection barrier) which could be modulated by delivery of analyte. Materials used in nanoscale devices, for example nanoparticles, nanotubes, and nanowires, are also briefly summarized in an attempt to introduce other relevant nano-transducers.

  16. Compound prioritization methods increase rates of chemical probe discovery in model organisms

    PubMed Central

    Wallace, Iain M; Urbanus, Malene L; Luciani, Genna M; Burns, Andrew R; Han, Mitchell KL; Wang, Hao; Arora, Kriti; Heisler, Lawrence E; Proctor, Michael; St. Onge, Robert P; Roemer, Terry; Roy, Peter J; Cummins, Carolyn L; Bader, Gary D; Nislow, Corey; Giaever, Guri

    2011-01-01

    SUMMARY Pre-selection of compounds that are more likely to induce a phenotype can increase the efficiency and reduce the costs for model organism screening. To identify such molecules, we screened ~81,000 compounds in S. cerevisiae and identified ~7,500 that inhibit cell growth. Screening these growth-inhibitory molecules across a diverse panel of model organisms resulted in an increased phenotypic hit-rate. This data was used to build a model to predict compounds that inhibit yeast growth. Empirical and in silico application of the model enriched the discovery of bioactive compounds in diverse model organisms. To demonstrate the potential of these molecules as lead chemical probes we used chemogenomic profiling in yeast and identified specific inhibitors of lanosterol synthase and of stearoyl-CoA 9-desaturase. As community resources, the ~7,500 growth-inhibitory molecules has been made commercially available and the computational model and filter used are provided. PMID:22035796

  17. Processing Research on Chemically Vapor Deposited Silicon Nitride.

    DTIC Science & Technology

    1979-12-01

    the feasi- bility of synthesizing free-standing plate and figured geometries of phase-pure silicon nitride by the chemical vapor deposition (CVD) method...ates toward moisture and the probability that they all contain absorbed ammonium chloride and ammonia. A strong ammoniacal odor indicates that...solid (V- L -S) processes favored by high ammonia/silicon ratios, high concentrations and long times. Whisker formation would be favored by the opposite

  18. Cost factors and chemical pretreatment effects in the membrane filtration of waters containing natural organic matter.

    PubMed

    Schäfer, A I; Fane, A G; Waite, T D

    2001-04-01

    This paper compares the membrane processes available for water treatment. Membranes have the advantage of currently decreasing capital cost, a relatively small footprint compared to conventional treatment, generally a reduction in chemicals usage and comparably low maintenance requirements. Three membrane processes applicable to water treatment, micro- (MF), ultra- (UF), and nanofiltration (NF), are compared in terms of intrinsic rejection, variation of rejection due to membrane fouling and increase in rejection by ferric chloride pretreatment. Twelve different membranes are compared on the basis of their membrane pore size which was calculated from their molecular weight cut-off. A pore size of < 6 nm is required to achieve substantial (> 50%) organics removal. For a fouled membrane this pore size is about 11 nm. UV rejection is higher than DOC rejection. Coagulation pretreatment allows a higher rejection of organics by MF and UF and the cut-off criterion due to initial membrane pore size is no longer valid. A water quality parameter (WQP) is introduced which describes the product water quality achieved as a function of colloid, DOC and cation rejection. The relationship between log (pore size) and WQP is linear. Estimation of membrane costs as a function of WQP suggests that open UF is superior to MF (similar cost at higher WQP) and NF is superior to tight UF. Chemical pretreatment could compensate for the difference between MF and UF. However, when considering chemicals and energy costs, it appears that a process operated at a higher energy is cheaper at a guaranteed product quality (less dependent on organic type). This argument is further supported by environmental issues of chemicals usage, as energy may be provided from renewable sources.

  19. Research on chemical vapor deposition processes for advanced ceramic coatings

    NASA Technical Reports Server (NTRS)

    Rosner, Daniel E.

    1993-01-01

    Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.

  20. 40 CFR Appendix A to Part 136 - Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Methods for Organic Chemical Analysis... FOR THE ANALYSIS OF POLLUTANTS Pt. 136, App. A, Meth. 601 Appendix A to Part 136—Methods for Organic.... Interferences 3.1Impurities in the purge gas and organic compounds outgassing from the plumbing ahead of...

  1. 40 CFR Appendix A to Part 136 - Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Methods for Organic Chemical Analysis... FOR THE ANALYSIS OF POLLUTANTS Pt. 136, App. A, Meth. 601 Appendix A to Part 136—Methods for Organic.... Interferences 3.1Impurities in the purge gas and organic compounds outgassing from the plumbing ahead of...

  2. 40 CFR Appendix A to Part 136 - Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Methods for Organic Chemical Analysis... FOR THE ANALYSIS OF POLLUTANTS Pt. 136, App. A, Meth. 601 Appendix A to Part 136—Methods for Organic.... Interferences 3.1Impurities in the purge gas and organic compounds outgassing from the plumbing ahead of...

  3. Plant organ chambers in plant physiology field research

    SciTech Connect

    Sinclair, T.R.

    1980-10-01

    Plant organ chambers used for measuring gas exchange demonstrate that with due-concern for the chamber environment and for the normal growth of the plants, useful data on physiological performance under field conditions can be collected. Recent advances in electronics, particularly the development of minicomputers and microprocessors, have greatly expanded the potential for monitoring and controlling plant organ chambers in field physiology research. These tools allow the scope of the research to be considerably broadened because many chambers can be observed essentially simultaneously and continuously on a long-term basis. The inherent limitations of artificialities and ambiguities in the data can be minimized by good control of the chamber environment and a multiplicity of chambers. While these technological advances allow intensive field physiological research, they also require a substantial commitment from the experimenter. During the data collection, a continuing, long-term effort is required to assure high quality data. Having completed the data collection, the experimenter is confronted with a very large volume of data that must be analyzed and interpreted. Yet, the rewards of these commitments appear to be an ever-increasing understanding of the physiological processes existing in plants grown under field conditions.

  4. Identification and quantification of individual chemical compounds in biogenic secondary organic aerosols using GCxGC-VUV/EI-HRTOFMS

    NASA Astrophysics Data System (ADS)

    Decker, M.; Worton, D. R.; Isaacman, G. A.; Chan, A. W.; Ruehl, C.; Zhao, Y.; Wilson, K. R.; Goldstein, A. H.

    2012-12-01

    Atmospheric aerosols have adverse effects on human health and air quality and affect radiative forcing and thus climate. While the organic fraction of aerosols is substantial, the sources and chemistry leading to the formation of secondary organic aerosols are very poorly understood. Characterizing individual compounds present in organic aerosol provides insights into the sources, formation mechanisms and oxidative transformations that have taken place. Fifteen aerosol samples collected over a 5 day period at the Blodgett Forest Research Station in the Sierra Nevada Mountains, part of the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) in July 2009, were analyzed using comprehensive two dimensional gas chromatography with high resolution time of flight mass spectrometry (GCxGC-HRTOFMS). Approximately 600 compounds were observed in each sample as significant peaks in the chromatogram. Of these, around a third were identified by matching the unique electron ionization (EI) mass spectrum of each compound to the NIST library of characteristic fragmentation patterns. One filter sample was also analyzed using vacuum ultraviolet ionization (VUV) instead of EI. This 'soft' ionization technique results in much less fragmentation yielding the molecular ion of each compound, from which the exact mass was determined. If the formula of the EI library matched compound equaled the high mass resolution VUV molecular weight within a certain tolerance (< 30 ppm), then the library match was considered confirmed; 226 compounds were identified in this way. Using the VUV technique 234 additional compounds that were not in the EI mass spectral database were assigned chemical formulas based on the observed molecular weights. The chemical formulas in conjunction with the location of the compound in the GCxGC chromatogram were used to provide further classification of these compounds based on their likely functionalization. The broad array of observed oxygenated

  5. Organizing patient safety research to identify risks and hazards

    PubMed Central

    Battles, J; Lilford, R

    2003-01-01

    Patient safety has become an international priority with major research programmes being carried out in the USA, UK, and elsewhere. The challenge is how to organize research efforts that will produce the greatest yield in making health care safer for patients. Patient safety research initiatives can be considered in three different stages: (1) identification of the risks and hazards; (2) design, implementation, and evaluation of patient safety practices; and (3) maintaining vigilance to ensure that a safe environment continues and patient safety cultures remain in place. Clearly, different research methods and approaches are needed at each of the different stages of the continuum. A number of research approaches can be used at stage 1 to identify risks and hazards including the use of medical records and administrative record review, event reporting, direct observation, process mapping, focus groups, probabilistic risk assessment, and safety culture assessment. No single method can be universally applied to identify risks and hazards in patient safety. Rather, multiple approaches using combinations of these methods should be used to increase identification of risks and hazards of health care associated injury or harm to patients. PMID:14645888

  6. Elucidating the Chemical Complexity of Organic Aerosol Constituents Measured During the Southeastern Oxidant and Aerosol Study (SOAS)

    NASA Astrophysics Data System (ADS)

    Yee, L.; Isaacman, G. A.; Spielman, S. R.; Worton, D. R.; Zhang, H.; Kreisberg, N. M.; Wilson, K. R.; Hering, S. V.; Goldstein, A. H.

    2013-12-01

    Thousands of volatile organic compounds are uniquely created in the atmosphere, many of which undergo chemical transformations that result in more highly-oxidized and often lower vapor pressure species. These species can contribute to secondary organic aerosol, a complex mixture of organic compounds that is still not chemically well-resolved. Organic aerosol collected on filters taken during the Southeastern Oxidant and Aerosol Study (SOAS) constitute hundreds of unique chemical compounds. Some of these include known anthropogenic and biogenic tracers characterized using standardized analytical techniques (e.g. GC-MS, UPLC, LC-MS), but the majority of the chemical diversity has yet to be explored. By employing analytical techniques involving sample derivatization and comprehensive two-dimensional gas chromatography (GC x GC) with high-resolution-time-of-flight mass spectrometry (HR-ToF-MS), we elucidate the chemical complexity of the organic aerosol matrix along the volatility and polarity grids. Further, by utilizing both electron impact (EI) and novel soft vacuum ultraviolet (VUV) ionization mass spectrometry, a greater fraction of the organic mass is fully speciated. The GC x GC-HR-ToF-MS with EI/VUV technique efficiently provides an unprecedented level of speciation for complex ambient samples. We present an extensive chemical characterization and quantification of organic species that goes beyond typical atmospheric tracers in the SOAS samples. We further demonstrate that complex organic mixtures can be chemically deconvoluted by elucidation of chemical formulae, volatility, functionality, and polarity. These parameters provide insight into the sources (anthropogenic vs. biogenic), chemical processes (oxidation pathways), and environmental factors (temperature, humidity), controlling organic aerosol growth in the Southeastern United States.

  7. Physicochemical properties of nonreactive volatile organic chemicals to estimate RD50: alternatives to animal studies.

    PubMed

    Alarie, Y; Nielsen, G D; Andonian-Haftvan, J; Abraham, M H

    1995-09-01

    This article presents the correlations obtained between the results on the potency of nonreactive airborne chemicals as sensory irritants and several of their physicochemical properties. The potency of airborne sensory irritants obtained from a reflexively induced decrease in respiratory frequency has been measured in the past using mice. Typically, their potency has been expressed as the exposure concentration necessary to decrease respiratory frequency by 50% (RD50). A large database of RD50 values is now available and such values are highly correlated with occupational exposure guidelines such as threshold limit values (TLVs). We used the nonreactive volatile organic chemicals from this database, for which relevant physicochemical variables are available or can be calculated. These variables were vapor pressure (P) or Ostwald gas-liquid partition coefficients (L). The liquids used for L values were n-hexadecane, octanol, N-formylmorpholine, tri-(2-ethylhexyl)phosphate, and olive oil. Excellent correlations were found between log RD50 and log P, as well as between log RD50 and log L16, log L(Oct), log L(NFM), log L(EHP), or log L(Oil). It follows that as an alternative to the bioassay, these physicochemical variables can be used to estimate RD50 of nonreactive volatile organic chemicals. Appropriate exceptions to general estimation of RD50 values from physicochemical variables are also presented, as well as the most appropriate estimates which can be obtained within homologous series.

  8. Review of existing terrestrial bioaccumulation models and terrestrial bioaccumulation modeling needs for organic chemicals.

    PubMed

    Gobas, Frank A P C; Burkhard, Lawrence P; Doucette, William J; Sappington, Keith G; Verbruggen, Eric M J; Hope, Bruce K; Bonnell, Mark A; Arnot, Jon A; Tarazona, Jose V

    2016-01-01

    Protocols for terrestrial bioaccumulation assessments are far less-developed than for aquatic systems. This article reviews modeling approaches that can be used to assess the terrestrial bioaccumulation potential of commercial organic chemicals. Models exist for plant, invertebrate, mammal, and avian species and for entire terrestrial food webs, including some that consider spatial factors. Limitations and gaps in terrestrial bioaccumulation modeling include the lack of QSARs for biotransformation and dietary assimilation efficiencies for terrestrial species; the lack of models and QSARs for important terrestrial species such as insects, amphibians and reptiles; the lack of standardized testing protocols for plants with limited development of plant models; and the limited chemical domain of existing bioaccumulation models and QSARs (e.g., primarily applicable to nonionic organic chemicals). There is an urgent need for high-quality field data sets for validating models and assessing their performance. There is a need to improve coordination among laboratory, field, and modeling efforts on bioaccumulative substances in order to improve the state of the science for challenging substances.

  9. Toxicity of organic chemical pollution in groundwater downgradient of a landfill (Grindsted, Denmark)

    SciTech Connect

    Baun, A.; Jensen, S.D.; Bjerg, P.L.; Christensen, T.H.; Nyholm, N.

    2000-05-01

    The aim of the present study was to describe the occurrence and distribution of toxicity related to organic chemical contaminants in the leachate plume downgradient of the Grindsted Landfill (Denmark). A total of 27 groundwater samples were preconcentrated by solid-phase extraction (SPE) using XAD-2 as the resin material. This treatment effectively eliminated sample matrix toxicity caused by inorganic salts and natural organic compounds and produced an aqueous concentrate of the nonvolatile chemical contaminants. The SPE extracts were tested in a battery of standardized short-term aquatic toxicity tests with luminescent bacteria (Vibrio fischeri), algae (Selenastrum capricornutum), and crustaceans (Daphnia magna). Additional genotoxicity tests were made using the umuC test (Salmonella typhimurium). Biotests with algae and luminescent bacteria were the most sensitive tests. On the basis of results with these two bioassays, it was concluded that SPE extracts of groundwater collected close to the landfill were toxic. The toxicity decreased with the distance from the landfill. At distances greater than 80 m from the border of the landfill, the groundwater toxicity was not significantly different from the background toxicity. SPE extracts were not toxic to Daphnia, and no genotoxicity was observed in the umuC test. The overall findings indicate that a battery of biotests applied on preconcentrated groundwater samples can be a useful tool for toxicity characterization and hazard ranking of groundwater polluted with complex chemical mixtures, such as landfill leachates.

  10. Photoelectrochemical power, chemical energy and catalytic activity for organic evolution on natural pyrite interfaces.

    PubMed

    Tributsch, H; Fiechter, S; Jokisch, D; Rojas-Chapana, J; Ellmer, K

    2003-04-01

    Natural pyrite (FeS2) has frequently been discussed as a material involved in CO2 fixation in presence of H2S and as a possible catalyst for the origin of life. A straightforward chemical fixation of carbon dioxide as proposed by Wächtershauser could not be verified from thermo-chemical equilibrium calculations by minimizing Gibb's Free Energy in the system C, O, H, S, Fe and appears unlikely due to the experimentally encountered large overpotentials involved in CO2 fixation. However, the hypothesis, by W. R. Edwards, that pyrite in shallow coastal waters may have been involved, can be sustained. In this case, daily available photoelectrochemical power from FeS2/Fe2+/3+ interfaces could have made the difference in combination with electrochemical processes, such as hydrogen insertion, and the solubilization of pyrite by the amino acid cysteine to yield dissolved chemical energy. Periodical changes in energy supply could also have entrained primitive self-organization processes for organic-biological evolution. Natural samples from thirteen ore deposits have been investigated photoelectrochemically. Efficient light-induced current generation has been found with several of these samples so that photoelectrochemical processes generated by pyrite have to be considered as naturally occurring phenomena, which could have been even more pronounced in oxygen deficient environments. Pyrite from the Murgul mine in Turkey of suboceanic volcanic origin was closer examined as a model system to understand the morphology and chemistry of pyrite photoactivity.

  11. Program of technical assistance to the organization for the prohibition of chemical weapons, informal report

    SciTech Connect

    Not Available

    1995-01-01

    Currently, U.S. organizations provide technical support to the U.S. Delegation for its work as part of the Preparatory Commission (PrepCom) of the Organization for the Prohibition of Chemical Weapons (OPCW) in The Hague. The current efforts of the PrepCom are focussed on preparations for the Entry-Into-Force (EIF) of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons (often referred to as the {open_quotes}Chemical Weapons Convention{close_quotes} (CWC)). EIF of the CWC is expected in 1995, and shortly thereafter the PrepCom will cease to exist, with the OPCW taking over responsibilities under the CWC. A U.S. program of technical assistance to the OPCW for its verification responsibilities may be created as part of U.S. policy objectives after EIF of the CWC. In the summary below, comments by participants are presented in Square Brackets Some of the same points arose several times during the discussions; they are grouped together under the most pertinent heading.

  12. Chemical and spectroscopic analyses of organic matter transformation in warming tundra soils

    NASA Astrophysics Data System (ADS)

    Herndon, E.; Roy Chowdhury, T.; Mann, B. F.; Graham, D. E.; Bargar, J.; Gu, B.; Liang, L.

    2013-12-01

    Many tundra soils are currently major carbon sinks; however, an increase in temperature may shift these systems to C sources and create a positive feedback for warming. In order to predict future C release from tundra soils, it is necessary to quantify rates of SOM degradation and to identify the reactants and products of microbial decomposition reactions. In this study, multiple spectroscopic techniques are used to investigate SOM during laboratory incubations of tundra soils. We aim to characterize the chemical transformation of organic matter during decomposition as a function of temperature and geochemistry. Frozen soil cores were obtained from the Barrow Environmental Observatory (BEO) in northern Alaska as part of the Next Generation Ecosystem Experiment Arctic project. To investigate the influence of temperature on organic matter degradation and compositional changes, soil horizons from each core were homogenized and soil material was incubated at -2°C, +4°C, or +8°C. Samples were sacrificed periodically over 100 days, and chemical and physical extractions were used to separate SOM into operationally-defined pools, including light (density < 1.6 g cm-2) and mineral-bound, and water-, acid-, base-, and non-soluble fractions. A suite of wet-chemical and spectroscopic analyses was used to measure CO2 and CH4 formation and soil C compositional changes, including techniques such as Fourier transform infrared spectroscopy, high performance liquid chromatography (HPLC), high resolution mass spectrometry, and X-ray absorption spectroscopy. Detailed chemical and spectroscopic analyses reveal significant differences amongst extracts and with depth in the soil. In general, more organic C was extracted in the base than in the acid and water fractions, and mineral-bound organic C increased with depth. The water-soluble C fraction showed the lowest molar absorptivity of the three extracts and consisted of mostly lower-molecular weight organics. Acid-soluble C increased

  13. Use of comparative genomics approaches to characterize interspecies differences in response to environmental chemicals: Challenges, opportunities, and research needs

    SciTech Connect

    Burgess-Herbert, Sarah L.; Euling, Susan Y.

    2013-09-15

    A critical challenge for environmental chemical risk assessment is the characterization and reduction of uncertainties introduced when extrapolating inferences from one species to another. The purpose of this article is to explore the challenges, opportunities, and research needs surrounding the issue of how genomics data and computational and systems level approaches can be applied to inform differences in response to environmental chemical exposure across species. We propose that the data, tools, and evolutionary framework of comparative genomics be adapted to inform interspecies differences in chemical mechanisms of action. We compare and contrast existing approaches, from disciplines as varied as evolutionary biology, systems biology, mathematics, and computer science, that can be used, modified, and combined in new ways to discover and characterize interspecies differences in chemical mechanism of action which, in turn, can be explored for application to risk assessment. We consider how genetic, protein, pathway, and network information can be interrogated from an evolutionary biology perspective to effectively characterize variations in biological processes of toxicological relevance among organisms. We conclude that comparative genomics approaches show promise for characterizing interspecies differences in mechanisms of action, and further, for improving our understanding of the uncertainties inherent in extrapolating inferences across species in both ecological and human health risk assessment. To achieve long-term relevance and consistent use in environmental chemical risk assessment, improved bioinformatics tools, computational methods robust to data gaps, and quantitative approaches for conducting extrapolations across species are critically needed. Specific areas ripe for research to address these needs are recommended.

  14. Uptake rate constants and partition coefficients for vapor phase organic chemicals using semipermeable membrane devices (SPMDs)

    USGS Publications Warehouse

    Cranor, W.L.; Alvarez, D.A.; Huckins, J.N.; Petty, J.D.

    2009-01-01

    To fully utilize semipermeable membrane devices (SPMDs) as passive samplers in air monitoring, data are required to accurately estimate airborne concentrations of environmental contaminants. Limited uptake rate constants (kua) and no SPMD air partitioning coefficient (Ksa) existed for vapor-phase contaminants. This research was conducted to expand the existing body of kinetic data for SPMD air sampling by determining kua and Ksa for a number of airborne contaminants including the chemical classes: polycyclic aromatic hydrocarbons, organochlorine pesticides, brominated diphenyl ethers, phthalate esters, synthetic pyrethroids, and organophosphate/organosulfur pesticides. The kuas were obtained for 48 of 50 chemicals investigated and ranged from 0.03 to 3.07??m3??g-1??d-1. In cases where uptake was approaching equilibrium, Ksas were approximated. Ksa values (no units) were determined or estimated for 48 of the chemicals investigated and ranging from 3.84E+5 to 7.34E+7. This research utilized a test system (United States Patent 6,877,724 B1) which afforded the capability to generate and maintain constant concentrations of vapor-phase chemical mixtures. The test system and experimental design employed gave reproducible results during experimental runs spanning more than two years. This reproducibility was shown by obtaining mean kua values (n??=??3) of anthracene and p,p???-DDE at 0.96 and 1.57??m3??g-1??d-1 with relative standard deviations of 8.4% and 8.6% respectively.

  15. Dermal absorption of neat and aqueous volatile organic chemicals in the Fischer 344 rat

    SciTech Connect

    Morgan, D.L.; Cooper, S.W.; Carlock, D.L.; Sykora, J.J.; Sutton, B.; Mattie, D.R.; McDougal, J.N. )

    1991-06-01

    Quantification of dermal absorption of volatile organic chemicals (VOCs) from aqueous solutions is required to understand the potential health hazards resulting from skin exposure to these chemicals in contaminated water. Male Fischer 344 rats were dermally exposed (3.1-cm2 dorsal skin) to neat, one-third saturated, two-thirds saturated, or saturated aqueous solutions of 14 VOCs for 24 hr. Blood samples were obtained via indwelling jugular catheters during exposure (0, 0.5, 1, 2, 4, 8, 12, and 24 hr), and analyzed for the VOCs by gas chromatography using headspace analysis. Absorption of the neat VOCs in this series of chemicals decreased as water solubility decreased. Peak blood levels of VOCs attained during exposure for 24 hr to neat chemicals were: 1,2-dichloroethane (135.1 micrograms/ml), bromochloromethane (113.3 micrograms/ml), chloroform (51.0 micrograms/ml), benzene (24.2 micrograms/ml), tetrachloroethylene (21.1 micrograms/ml), dibromomethane (18.2 micrograms/ml), trichloroethylene (11.6 micrograms/ml), toluene (9.5 micrograms/ml), xylene (8.8 micrograms/ml), hexane (8.0 micrograms/ml), ethylbenzene (5.6 micrograms/ml), styrene (5.3 micrograms/ml), carbon tetrachloride (5.0 micrograms/ml), and 1,1,1-trichloroethane (3.4 micrograms/ml). Blood levels of 1,2-dichloroethane and benzene continued to increase during the 24-hr exposure to neat chemical, while blood levels of the other neat VOCs peaked within 4 hr and then either decreased or remained about the same for the duration of the exposure. Absorption of VOCs from one-third, two-thirds, or saturated aqueous solutions was rapid, and resulted in depletion of the chemical from the solution although only a small amount of water was absorbed. Blood levels of each VOC were directly related to the exposure concentrations.

  16. Dissolved organic carbon in Alaskan boreal forest: Sources, chemical characteristics, and biodegradability

    USGS Publications Warehouse

    Wickland, K.P.; Neff, J.C.; Aiken, G.R.

    2007-01-01

    The fate of terrestrially-derived dissolved organic carbon (DOC) is important to carbon (C) cycling in both terrestrial and aquatic environments, and recent evidence suggests that climate warming is influencing DOC dynamics in northern ecosystems. To understand what determines the fate of terrestrial DOC, it is essential to quantify the chemical nature and potential biodegradability of this DOC. We examined DOC chemical characteristics and biodegradability collected from soil pore waters and dominant vegetation species in four boreal black spruce forest sites in Alaska spanning a range of hydrologic regimes and permafrost extents (Well Drained, Moderately Well Drained, Poorly Drained, and Thermokarst Wetlands). DOC chemistry was characterized using fractionation, UV-Vis absorbance, and fluorescence measurements. Potential biodegradability was assessed by incubating the samples and measuring CO2 production over 1 month. Soil pore water DOC from all sites was dominated by hydrophobic acids and was highly aromatic, whereas the chemical composition of vegetation leachate DOC varied significantly with species. There was no seasonal variability in soil pore water DOC chemical characteristics or biodegradability; however, DOC collected from the Poorly Drained site was significantly less biodegradable than DOC from the other three sites (6% loss vs. 13-15% loss). The biodegradability of vegetation-derived DOC ranged from 10 to 90% loss, and was strongly correlated with hydrophilic DOC content. Vegetation such as Sphagnum moss and feathermosses yielded DOC that was quickly metabolized and respired. In contrast, the DOC leached from vegetation such as black spruce was moderately recalcitrant. Changes in DOC chemical characteristics that occurred during microbial metabolism of DOC were quantified using fractionation and fluorescence. The chemical characteristics and biodegradability of DOC in soil pore waters were most similar to the moderately recalcitrant vegetation

  17. The impact of chemical pollution on the resilience of soils under multiple stresses: A conceptual framework for future research.

    PubMed

    Schaeffer, Andreas; Amelung, Wulf; Hollert, Henner; Kaestner, Matthias; Kandeler, Ellen; Kruse, Jens; Miltner, Anja; Ottermanns, Richard; Pagel, Holger; Peth, Stephan; Poll, Christian; Rambold, Gerhard; Schloter, Michael; Schulz, Stefanie; Streck, Thilo; Roß-Nickoll, Martina

    2016-10-15

    Soils are faced with man-made chemical stress factors, such as the input of organic or metal-containing pesticides, in combination with non-chemical stressors like soil compaction and natural disturbance like drought. Although multiple stress factors are typically co-occurring in soil ecosystems, research in soil sciences on this aspect is limited and focuses mostly on single structural or functional endpoints. A mechanistic understanding of the reaction of soils to multiple stressors is currently lacking. Based on a review of resilience theory, we introduce a new concept for research on the ability of polluted soil (xenobiotics or other chemical pollutants as one stressor) to resist further natural or anthropogenic stress and to retain its functions and structure. There is strong indication that pollution as a primary stressor will change the system reaction of soil, i.e., its resilience, stability and resistance. It can be expected that pollution affects the physiological adaption of organisms and the functional redundancy of the soil to further stress. We hypothesize that the recovery of organisms and chemical-physical properties after impact of a follow-up stressor is faster in polluted soil than in non-polluted soil, i.e., polluted soil has a higher dynamical stability (dynamical stability=1/recovery time), whereas resilience of the contaminated soil is lower compared to that of not or less contaminated soil. Thus, a polluted soil might be more prone to change into another system regime after occurrence of further stress. We highlight this issue by compiling the literature exemplarily for the effects of Cu contamination and compaction on soil functions and structure. We propose to intensify research on effects of combined stresses involving a multidisciplinary team of experts and provide suggestions for corresponding experiments. Our concept offers thus a framework for system level analysis of soils paving the way to enhance ecological theory.

  18. Peptide-Metal Organic Framework Swimmers that Direct the Motion toward Chemical Targets.

    PubMed

    Ikezoe, Yasuhiro; Fang, Justin; Wasik, Tomasz L; Shi, Menglu; Uemura, Takashi; Kitagawa, Susumu; Matsui, Hiroshi

    2015-06-10

    Highly efficient and robust chemical motors are expected for the application in microbots that can selectively swim toward targets and accomplish their tasks in sensing, labeling, and delivering. However, one of major issues for such development is that current artificial swimmers have difficulty controlling their directional motion toward targets like bacterial chemotaxis. To program synthetic motors with sensing capability for the target-directed motion, we need to develop swimmers whose motions are sensitive to chemical gradients in environments. Here we create a new intelligent biochemical swimmer by integrating metal organic frameworks (MOFs) and peptides that can sense toxic heavy metals in solution and swim toward the targets. With the aid of Pb-binding enzymes, the peptide-MOF motor can directionally swim toward PbSe quantum dots (QD) by sensing pH gradient and eventually complete the motion as the swimmer reaches the highest gradient point at the target position in solution. This type of technology could be evolved to miniaturize chemical robotic systems that sense target chemicals and swim toward target locations.

  19. Chemical characterization of high molecular weight dissolved organic matter in fresh and marine waters

    NASA Astrophysics Data System (ADS)

    Repeta, Daniel J.; Quan, Tracy M.; Aluwihare, Lihini I.; Accardi, AmyMarie

    2002-03-01

    The high molecular weight fraction of dissolved organic matter in a suite of lakes, rivers, seawater, and marine sediment interstitial water samples was collected by ultrafiltration and characterized by molecular level and spectroscopic techniques. Proton nuclear magnetic resonance spectra of all samples show a high degree of similarity, with major contributions from carbohydrates, bound acetate, and lipids. Molecular level analyses of neutral sugars show seven monosaccharides, rhamnose, fucose, arabinose, xylose, mannose, glucose, and galactose, to be abundant, and to occur in comparable relative amounts in each sample. Previous studies have emphasized the distinctive composition of dissolved humic substances in fresh and marine waters, and have attributed these differences to sources and transformations of organic matter unique to each environment. In contrast we find a large fraction of freshwater high molecular weight dissolved organic matter (HMWDOM; > 1kD) to be indistinguishable from marine HMWDOM in bulk and molecular-level chemical properties. Aquatic HMWDOM is similar in chemical composition to biologically derived acylated heteropolysaccharides isolated from marine algal cultures, suggesting a biological source for some fraction of persistent HMWDOM. High molecular weight DOC contributes 51 ± 26% of the total DOC, and monosaccharides 18 ± 8% of the total HMWDOC in our freshwater samples. These contributions are on average higher and more variable, but not significantly different than for surface seawater (30% and 16% respectively). Biogeochemical processes that produce, accumulate, and recycle DOM may therefore share important similarities and be broadly comparable across a range of environmental settings.

  20. [Source profile and chemical reactivity of volatile organic compounds from vehicle exhaust].

    PubMed

    Qiao, Yue-Zhen; Wang, Hong-Li; Huang, Cheng; Chen, Chang-Hong; Su, Lei-Yan; Zhou, Min; Xu, Hua; Zhang, Gang-Feng; Chen, Yi-Ran; Li, Li; Chen, Ming-Hua; Huang, Hai-Ying

    2012-04-01

    Light-duty gasoline taxis (LDGT) and passenger cars (LDGV), heavy-duty diesel buses (HDDB) and trucks (HDDT), gasoline motorcycles (MC) and LPG scooters (LPGS), were selected for tailpipe volatile organic compounds (VOCs) samplings by using transient dynamometer and on road test combined with SUMMA canisters technology. The samples were tested by GC-MS to analyze the concentration and species composition of VOCs. The results indicate that light-duty gasoline automobiles have higher fractions of aromatic hydrocarbons, which account for 43.38%-44.45% of the total VOCs, the main aromatic hydrocarbons are toluene and xylenes. Heavy-duty diesel vehicles have higher fractions of alkanes, which constitute 46.86%-48.57% of the total VOCs, the main alkanes are propane, n-dodecane and n-undecane. In addition, oxy-organics account for 13.28%-15.01% of the VOCs, the main oxy-organics is acetone. The major compound from MC and LPGS exhaust is acetylene, it accounts for 39.75% and 76.67% of the total VOCs, respectively. VOCs exhaust from gasoline motorcycles and light-duty gasoline automobiles has a significantly higher chemical reactivity than those from heavy-duty diesel vehicles, which contribute 55% and 44% to the atmospheric chemical reactivity in Shanghai. The gasoline motorcycles and light-duty gasoline automobiles are the key pollution sources affecting city and region ambient oxidation, and the key active species of toluene, xylenes, propylene, and styrene make the greatest contribution.

  1. Some critical issues and concerns related to research advances on toxicology of chemical mixtures.

    PubMed Central

    Yang, R S

    1998-01-01

    This paper addresses some of the issues and concerns on research advances on the toxicology of chemical mixtures. Emphases will be selectively given to the following questions and answers: Can mechanistic studies be conducted on chemical mixtures? The fact that any studies, including mechanistic studies, of single chemicals are really the study of the parent chemical plus its metabolites underscores the relevance of mechanistic studies on chemical mixtures. Can predictions be made on the health effects of chemical mixtures? Some successes are already evident in the literature on simpler chemical mixtures. For more complex mixtures, it is possible and we propose an approach here. What can we learn from other disciplines (the importance of interdisciplinary collaboration)? Two aspects, the knowledge and methodologies available in clinical pharmacology and the latest advances in structure-oriented lumping in chemical engineering, are discussed in detail. Unrepeatable results: The possibility of magnification of biologic variability because of low-level exposures to chemical mixtures is suggested with special reference to some known examples, including the controversial study on synergistic interactions of endocrine disruptors. Is the driving force for scientific investigations on chemical mixtures the legislative and regulatory atmosphere? Two laws with chemical mixtures specifically in the language are quoted and discussed. Their implications regarding research funding and activities are described. What are the pitfalls of applying for research funding on investigating chemical mixtures? The dilemma at least one investigator faces in pursuing research funding is elaborated. The questions and issues listed above are not all inclusive, but they represent some of the aspects that need to be brought into the open in the scientific community for discussion and/or debate. Thus, the primary objective of this paper is to provide some momentum for the beginning of a fruitful

  2. Oil spill chemical dispersants: Research, experience and recommendations

    SciTech Connect

    Allen, T.E.

    1982-01-01

    This book presents papers on the use of surfactants for the control of oil spills. Topics considered include laboratory toxicity effectiveness testing, the characteristics of spilled oil, salinity, water temperature, field effectiveness, dilution processes, remote sensing, oil spill fire hazards, the toxicity of oil spill dispersants to marine organisms, the effects of dispersed oil in marine sediments, dispersants for spill countermeasures on arctic beaches, contingency planning and guidelines, ecological considerations, and a multifaceted approach to applying dispersants.

  3. Organization of Biomedical Data for Collaborative Scientific Research: A Research Information Management System.

    PubMed

    Myneni, Sahiti; Patel, Vimla L

    2010-06-01

    Biomedical researchers often work with massive, detailed and heterogeneous datasets. These datasets raise new challenges of information organization and management for scientific interpretation, as they demand much of the researchers' time and attention. The current study investigated the nature of the problems that researchers face when dealing with such data. Four major problems identified with existing biomedical scientific information management methods were related to data organization, data sharing, collaboration, and publications. Therefore, there is a compelling need to develop an efficient and user-friendly information management system to handle the biomedical research data. This study evaluated the implementation of an information management system, which was introduced as part of the collaborative research to increase scientific productivity in a research laboratory. Laboratory members seemed to exhibit frustration during the implementation process. However, empirical findings revealed that they gained new knowledge and completed specified tasks while working together with the new system. Hence, researchers are urged to persist and persevere when dealing with any new technology, including an information management system in a research laboratory environment.

  4. Quarterly Progress Report for the Chemical and Energy Research Section of the Chemical Technology Division: July-September 1999

    SciTech Connect

    Jubin, R.T.

    2001-04-16

    This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period July-September 1999. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within ten major areas of research: Hot Cell Operations, Process Chemistry, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Physical Properties Research, Biochemical Engineering, Separations and Materials Synthesis, Fluid Structures and Properties, Biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information. Activities conducted within the area of the Cell Operations involved the testing of two continuously stirred tank reactors in series to evaluate the Savannah River-developed process of small-tank tetraphenylborate precipitation to remove cesium, strontium and transuranics from supernatant. Within the area of Process Chemistry, various topics related to solids formation in process solutions from caustic treatment of Hanford sludge were addressed. Saltcake dissolution efforts continued, including the development of a predictive algorithm. New initiatives for the section included modeling activities centered on detection of hydrogen in {sup 233}U storage wells and wax formation in petroleum mixtures, as well as support for the Spallation Neutron Source (investigation of transmutation products formed during operation). Other activities involved in situ grouting and evaluation of options for use (i.e., as castable shapes) of depleted uranium. In a continuation of activities of the preceding

  5. Water-stable organic transistors and their application in chemical and biological sensors

    PubMed Central

    Roberts, Mark E.; Mannsfeld, Stefan C. B.; Queraltó, Núria; Reese, Colin; Locklin, Jason; Knoll, Wolfgang; Bao, Zhenan

    2008-01-01

    The development of low-cost, reliable sensors will rely on devices capable of converting an analyte binding event to an easily read electrical signal. Organic thin-film transistors (OTFTs) are ideal for inexpensive, single-use chemical or biological sensors because of their compatibility with flexible, large-area substrates, simple processing, and highly tunable active layer materials. We have fabricated low-operating voltage OTFTs with a cross-linked polymer gate dielectric, which display stable operation under aqueous conditions over >104 electrical cycles using the p-channel semiconductor 5,5′-bis-(7-dodecyl-9H-fluoren-2-yl)-2,2′-bithiophene (DDFTTF). OTFT sensors were demonstrated in aqueous solutions with concentrations as low as parts per billion for trinitrobenzene, methylphosphonic acid, cysteine, and glucose. This work demonstrates of reliable OTFT operation in aqueous media, hence opening new possibilities of chemical and biological sensing with OTFTs. PMID:18711145

  6. Multilayer Graphene with Chemical Modification as Transparent Conducting Electrodes in Organic Light-Emitting Diode.

    PubMed

    Xu, Yilin; Yu, Haojian; Wang, Cong; Cao, Jin; Chen, Yigang; Ma, Zhongquan; You, Ying; Wan, Jixiang; Fang, Xiaohong; Chen, Xiaoyuan

    2017-12-01

    Graphene is a promising candidate for the replacement of the typical transparent electrode indium tin oxide in optoelectronic devices. Currently, the application of polycrystalline graphene films grown by chemical vapor deposition is limited for their low electrical conductivity due to the poor transfer technique. In this work, we developed a new method of preparing tri-layer graphene films with chemical modification and explored the influence of doping and patterning process on the performance of the graphene films as transparent electrodes. In order to demonstrate the application of the tri-layer graphene films in optoelectronics, we fabricated the organic light-emitting diodes (OLEDs) based on them and found that plasma etching is feasible with certain influence on the quality of the graphene films and the performance of the OLEDs.

  7. Oxidative metabolism of chemical pollutants in marine organisms: molecular and biochemical biomarkers in environmental toxicology.

    PubMed

    Benedetti, Maura; Giuliani, Maria Elisa; Regoli, Francesco

    2015-03-01

    Oxidative stress biomarkers are widely used in marine ecotoxicology. Environmental pollutants enhance intracellular formation of oxyradicals through several mechanisms, but complex oxidative interactions occur in response to chemical mixtures. Metabolism of individual classes of pollutants can be influenced by a sophisticated network of prooxidant relationships, reciprocal and cascade effects, changes of redox-sensitive signaling proteins, and transcription factors. Chemically mediated pathways can affect antioxidant responses at different levels, including pretranscriptional, transcriptional, protein, and catalytic functions; such mechanisms remain largely unexplored in marine organisms. Molecular responses of antioxidants are frequently not paralleled by expected biochemical changes or cellular effects, and caution is needed when interpreting the effects of environmental pollutants. Results on antioxidant variations can be influenced by mRNA stability and protein turnover, different timing for transcriptional and translational mechanisms, metabolic capability of tissues, posttranscriptional modifications of proteins, biphasic responses of antioxidant enzymes, and adaptation mechanisms to chronic pollution.

  8. Impact of organic carbon on weathering and chemical denudation of granular basalt

    NASA Astrophysics Data System (ADS)

    Dontsova, Katerina; Zaharescu, Dragos; Henderson, Whitney; Verghese, Sarah; Perdrial, Nicolas; Hunt, Edward; Chorover, Jon

    2014-08-01

    Bench-scale experiments were conducted to determine rates and patterns of coupled organic matter infusion and weathering in a San Francisco volcanic field (Flagstaff, AZ) basalt sample under experimentally-modeled biotic and abiotic condition and to inform larger-scale collaborative studies at the landscape evolution observatory (LEO), Biosphere 2 (Tucson, AZ), where the same basaltic media is being used in a synthetic hillslope experiment. We postulated that mineral transformations depend significantly on the presence of organic carbon compounds including dissolved natural organic matter (DOM), with organic C simultaneously imprinting the chemical and mineralogical properties of primary and secondary solids undergoing incongruent dissolution. The present work reports on solute releases from Flagstaff basalt (FB) along laboratory-controlled gradients in DOM type and concentration. Loamy sand textured FB was subjected to flow-through, saturated column dissolution experiments using influent solutions with and without DOM compounds. Solutions included Ponderosa pine forest soil O-horizon extracts at three target concentrations: 7, 35, and 70 mg L-1 C, malic acid (MA) solutions at 7, 35, 70, and 140 mg L-1 C, and a control without DOM but having comparable inorganic solution composition. Chemical denudation rates for FB dissolution products were calculated from the concentration difference between outflow and inflow solutions. In addition, changes in the composition of the solid phase over the course of the experiment were determined using X-ray diffraction (XRD), X-ray fluorescence (XRF), and selective dissolution (SE). Column experiments supported dissolution rates derived from the literature and indicated a potentially strong effect of plant-derived organic ligands on mineral dissolution congruency and secondary phase precipitation. Both malic acid and DOM enhanced basalt dissolution, with malic acid having larger effect on per unit C basis. The largest relative

  9. Use of Research-Based Instructional Strategies in Core Chemical Engineering Courses

    ERIC Educational Resources Information Center

    Prince, Michael; Borrego, Maura; Henderson, Charles; Cutler, Stephanie; Froyd, Jeff

    2013-01-01

    Traditional lecturing remains the most prevalent mode of instruction despite overwhelming research showing the increased effectiveness of many alternate instructional strategies. This study examines chemical engineering instructors' awareness and use of 12 such instructional strategies. The study also examines how chemical engineering…

  10. Modeling the Detection of Organic and Inorganic Compounds Using Iodide-Based Chemical Ionization.

    PubMed

    Iyer, Siddharth; Lopez-Hilfiker, Felipe; Lee, Ben H; Thornton, Joel A; Kurtén, Theo

    2016-02-04

    Iodide-based chemical ionization mass spectrometry (CIMS) has been used to detect and measure concentrations of several atmospherically relevant organic and inorganic compounds. The significant electronegativity of iodide and the strong acidity of hydroiodic acid makes electron transfer and proton abstraction essentially negligible, and the soft nature of the adduct formation ionization technique reduces the chances of sample fragmentation. In addition, iodide has a large negative mass defect, which, when combined with the high resolving power of a high resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS), provides good selectivity. In this work, we use quantum chemical methods to calculate the binding energies, enthalpies and free energies for clusters of an iodide ion with a number of atmospherically relevant organic and inorganic compounds. Systematic configurational sampling of the free molecules and clusters was carried out at the B3LYP/6-31G* level, followed by subsequent calculations at the PBE/SDD and DLPNO-CCSD(T)/def2-QZVPP//PBE/aug-cc-pVTZ-PP levels. The binding energies, enthalpies, and free energies thus obtained were then compared to the iodide-based University of Washington HR-ToF-CIMS (UW-CIMS) instrument sensitivities for these molecules. We observed a reasonably linear relationship between the cluster binding enthalpies and logarithmic instrument sensitivities already at the PBE/SDD level, which indicates that relatively simple quantum chemical methods can predict the sensitivity of an iodide-based CIMS instrument toward most molecules. However, higher level calculations were needed to treat some outlier molecules, most notably oxalic acid and methylerythritol. Our calculations also corroborated the recent experimental findings that the molecules that the UW-CIMS detects at maximum sensitivity usually have binding enthalpies to iodide which are higher than about 26 kcal/mol, depending slightly on the level of theory.

  11. Chemoreception Regulates Chemical Access to Mouse Vomeronasal Organ: Role of Solitary Chemosensory Cells

    PubMed Central

    Ogura, Tatsuya; Krosnowski, Kurt; Zhang, Lana; Bekkerman, Mikhael; Lin, Weihong

    2010-01-01

    Controlling stimulus access to sensory organs allows animals to optimize sensory reception and prevent damage. The vomeronasal organ (VNO) detects pheromones and other semiochemicals to regulate innate social and sexual behaviors. This semiochemical detection generally requires the VNO to draw in chemical fluids, such as bodily secretions, which are complex in composition and can be contaminated. Little is known about whether and how chemical constituents are monitored to regulate the fluid access to the VNO. Using transgenic mice and immunolabeling, we found that solitary chemosensory cells (SCCs) reside densely at the entrance duct of the VNO. In this region, most of the intraepithelial trigeminal fibers innervate the SCCs, indicating that SCCs relay sensory information onto the trigeminal fibers. These SCCs express transient receptor potential channel M5 (TRPM5) and the phospholipase C (PLC) β2 signaling pathway. Additionally, the SCCs express choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) for synthesizing and packaging acetylcholine, a potential transmitter. In intracellular Ca2+ imaging, the SCCs responded to various chemical stimuli including high concentrations of odorants and bitter compounds. The responses were suppressed significantly by a PLC inhibitor, suggesting involvement of the PLC pathway. Further, we developed a quantitative dye assay to show that the amount of stimulus fluid that entered the VNOs of behaving mice is inversely correlated to the concentration of odorous and bitter substances in the fluid. Genetic knockout and pharmacological inhibition of TRPM5 resulted in larger amounts of bitter compounds entering the VNOs. Our data uncovered that chemoreception of fluid constituents regulates chemical access to the VNO and plays an important role in limiting the access of non-specific irritating and harmful substances. Our results also provide new insight into the emerging role of SCCs in chemoreception and

  12. A new sampler for collecting separate dry and wet atmospheric depositions of trace organic chemicals

    NASA Astrophysics Data System (ADS)

    Waite, Don T.; Cessna, Allan J.; Gurprasad, Narine P.; Banner, James

    Studies conducted in Saskatchewan and elsewhere have demonstrated the atmospheric transport of agricultural pesticides and other organic contaminants and their deposition into aquatic ecosystems. To date these studies have focused on ambient concentrations in the atmosphere and in wet precipitation. To measure the dry deposition of organic chemicals, a new sampler was designed which uses a moving sheet of water to passively trap dry particles and gasses. The moving sheet of water drains into a reservoir and, during recirculation through the sampler, is passed through an XAD-2 resin column which adsorbs the trapped organic contaminants. All surfaces which contact the process water are stainless steel or Teflon. Chemicals collected can be related to airborne materials depositing into aquatic ecosystems. The sampler has received a United States patent (number 5,413,003 - 9 May 1996) with the Canadian patent pending. XAD-2 resin adsorption efficiencies for 10 or 50 μg fortifications of ten pesticides ranged from 76% for atrazine (2-chloro-4-ethylamino-6-isopropylamino- S-triazine) to 110% for triallate [ S-(2,3,3-trichloro-2-phenyl)bis(1-methylethyl)carbamothioate], dicamba (2-methoxy-3,6-dichlorobenzoic acid) and toxaphene (chlorinated camphene mixture). Field testing using duplicate samplers showed good reproducibility and amounts trapped were consistent with those from high volume and bulk pan samplers located on the same site. Average atmospheric dry deposition rates of three chemicals, collected for 5 weeks in May and June, were: dicamba, 69 ng m -2 da -1; 2,4-D (2,4-dichlorophenoxyacetic acid), 276 ng m -2 da -1: and, γ-HCH ( γ-1, 2, 3, 4, 5, 6-hexachlorocyclohexane), 327 ng m -2 da -1.

  13. Research in Chemical Kinetics: Progress Report, January 1, 1978 to September 30, 1978

    DOE R&D Accomplishments Database

    Rowland, F. S.

    1978-01-01

    Research was conducted on the following topics: stratospheric chemistry of chlorinated molecules, atmospheric chemistry of methane, atmospheric chemistry of cosmogenic tritium, reactions of energetic and thermal radioactive atoms, methylene chemistry, and laboratory simulation of chemical reactions in Jupiter atmosphere. (DLC)

  14. Physical and Chemical Sciences Center - research briefs. Volume 1-96

    SciTech Connect

    Mattern, P.L.

    1994-12-31

    This report provides brief summaries of research performed in chemical and physical sciences at Sandia National Laboratories. Programs are described in the areas of advanced materials and technology, applied physics and chemistry, lasers, optics, and vision, and resources and capabilities.

  15. Expedient Caution: Approximating Exposure and Dosimetry to Understand Chemical Risk (OSU EMT Research Day keynote presentation)

    EPA Science Inventory

    I describe research on high throughput exposure and toxicokinetics. These tools provide context for data generated by high throughput toxicity screening to allow risk-based prioritization of thousands of chemicals.

  16. Researches on Preliminary Chemical Reactions in Spark-Ignition Engines

    NASA Technical Reports Server (NTRS)

    Muehlner, E.

    1943-01-01

    Chemical reactions can demonstrably occur in a fuel-air mixture compressed in the working cylinder of an Otto-cycle (spark ignition) internal-combustion engine even before the charge is ignited by the flame proceeding from the sparking plug. These are the so-called "prelinminary reactions" ("pre-flame" combustion or oxidation), and an exact knowledge of their characteristic development is of great importance for a correct appreciation of the phenomena of engine-knock (detonation), and consequently for its avoidance. Such reactions can be studied either in a working engine cylinder or in a combustion bomb. The first method necessitates a complicated experimental technique, while the second has the disadvantage of enabling only a single reaction to be studied at one time. Consequently, a new series of experiments was inaugurated, conducted in a motored (externally-driven) experimental engine of mixture-compression type, without ignition, the resulting preliminary reactions being detectable and measurable thermometrically.

  17. Chemical research on red pigments after adverse reactions to tattoo.

    PubMed

    Tammaro, A; Toniolo, C; Giulianelli, V; Serafini, M; Persechino, S

    2016-03-01

    Currently, the incidence of tattooing is on the rise compared to the past, especially among adolescents, and it leads to the urgency of monitoring the security status of tattooing centers, as well as to inform people about the risks of tattoo practice. In our clinical experience, 20% of tattooed patients presented adverse reactions, like allergic contact dermatitis, psoriasis with Koebner's phenomena and granulomatous reactions, with the latter most prevalent and most often related to red pigment. Adverse reactions to tattoo pigments, especially the red one, are well known and described in literature. Great attention has to be focused on the pigments used, especially for the presence of new substances, often not well known. For this reason, we decided to perform a study on 12 samples of red tattoo ink, obtained by patients affected by different cutaneous reactions in the site of tattoo, to analyze their chemical composition.

  18. Method of making AlInSb by metal-organic chemical vapor deposition

    DOEpatents

    Biefeld, Robert M.; Allerman, Andrew A.; Baucom, Kevin C.

    2000-01-01

    A method for producing aluminum-indium-antimony materials by metal-organic chemical vapor deposition (MOCVD). This invention provides a method of producing Al.sub.X In.sub.1-x Sb crystalline materials by MOCVD wherein an Al source material, an In source material and an Sb source material are supplied as a gas to a heated substrate in a chamber, said Al source material, In source material, and Sb source material decomposing at least partially below 525.degree. C. to produce Al.sub.x In.sub.1-x Sb crystalline materials wherein x is greater than 0.002 and less than one.

  19. Structurally Integrated Photoluminescent Chemical and Biological Sensors: An Organic Light-Emitting Diode-Based Platform

    NASA Astrophysics Data System (ADS)

    Shinar, J.; Shinar, R.

    The chapter describes the development, advantages, challenges, and potential of an emerging, compact photoluminescence-based sensing platform for chemical and biological analytes, including multiple analytes. In this platform, the excitation source is an array of organic light-emitting device (OLED) pixels that is structurally integrated with the sensing component. Steps towards advanced integration with additionally a thin-film-based photodetector are also described. The performance of the OLED-based sensing platform is examined for gas-phase and dissolved oxygen, glucose, lactate, ethanol, hydrazine, and anthrax lethal factor.

  20. Chemically Stable Covalent Organic Framework (COF)-Polybenzimidazole Hybrid Membranes: Enhanced Gas Separation through Pore Modulation.

    PubMed

    Biswal, Bishnu P; Chaudhari, Harshal D; Banerjee, Rahul; Kharul, Ulhas K

    2016-03-24

    Highly flexible, TpPa-1@PBI-BuI and TpBD@PBI-BuI hybrid membranes based on chemically stable covalent organic frameworks (COFs) could be obtained with the polymer. The loading obtained was substantially higher (50 %) than generally observed with MOFs. These hybrid membranes show an exciting enhancement in permeability (about sevenfold) with appreciable separation factors for CO2/N2 and CO2/CH4. Further, we found that with COF pore modulation, the gas permeability can be systematically enhanced.

  1. Metal organic chemical vapor deposition of phase change Ge1Sb2Te4 nanowires.

    PubMed

    Longo, Massimo; Fallica, Roberto; Wiemer, Claudia; Salicio, Olivier; Fanciulli, Marco; Rotunno, Enzo; Lazzarini, Laura

    2012-03-14

    The self-assembly of Ge(1)Sb(2)Te(4) nanowires (NWs) for phase change memories application was achieved by metal organic chemical vapor deposition, catalyzed by Au nanoislands in a narrow range of temperatures and deposition pressures. In the optimized conditions of 400 °C, 50 mbar, the NWs are Ge(1)Sb(2)Te(4) single hexagonal crystals. Phase change memory switching was reversibly induced by nanosecond current pulses through metal-contacted NWs with threshold voltage of about 1.35 V.

  2. Collaborative Core Research Program for Chemical-Biological Warfare Defense

    DTIC Science & Technology

    2015-01-04

    assay on neuroblastoma cell lines. We performed this method, as well as incorporated a novel method developed at US Army Medical Research Institute of... neuroblastoma cells and networked cholinergic neurons, our data provides more accurate experimental estimates for transitioning to in vivo assays

  3. Chemical Structure and Accidental Explosion Risk in the Research Laboratory

    ERIC Educational Resources Information Center

    Churchill, David G.

    2006-01-01

    Tips that laboratory researchers and beginning graduate students can use to safeguard against explosion hazard with emphasis on clear illustrations of molecular structure are discussed. Those working with hazardous materials must proceed cautiously and may want to consider alternative and synthetic routes.

  4. Genomics and proteomics in chemical warfare agent research: recent studies and future applications.

    PubMed

    Everley, Patrick A; Dillman, James F

    2010-10-20

    Medical research on the effects of chemical warfare agents (CWAs) has been ongoing for nearly 100 years, yet these agents continue to pose a serious threat to deployed military forces and civilian populations. CWAs are extremely toxic, relatively inexpensive, and easy to produce, making them a legitimate weapon of choice for terrorist organizations. While the mechanisms of action for many CWAs have been known for years, questions about their molecular effects following acute and chronic exposure remain largely unanswered. Global approaches that can pinpoint which cellular pathways are altered in response to CWAs and characterize long-term toxicity have not been widely used. Fortunately, innovations in genomics and proteomics technologies now allow for thousands of genes and proteins to be identified and subsequently quantified in a single experiment. Advanced bioinformatics software can also help decipher large-scale changes observed, leading to mapping of signaling pathways, functional characterization, and identification of potential therapeutic targets. Here we present an overview of how genomics and proteomics technologies have been applied to CWA research and also provide a series of questions focused on how these techniques could further our understanding of CWA toxicity.

  5. Degradation of hazardous chemicals in liquid radioactive wastes from biomedical research using a mixed microbial population

    SciTech Connect

    Wolfram, J.H.; Radtke, M.; Wey, J.E.; Rogers, R.D.; Rau, E.H.

    1997-10-01

    As the costs associated with treatment of mixed wastes by conventional methods increase, new technologies will be investigated as alternatives. This study examines the potential of using a selected mixed population of microorganisms to treat hazardous chemical compounds in liquid low level radioactive wastes from biomedical research procedures. Microorganisms were isolated from various waste samples and enriched against compounds known to occur in the wastes. Individual isolates were tested for their ability to degrade methanol, ethanol, phenol, toluene, phthalates, acetonitrile, chloroform, and trichloroacetic acid. Following these tests, the organisms were combined in a media with a mixture of the different compounds. Three compounds: methanol, acetonitrile, and pseudocumene, were combined at 500 microliter/liter each. Degradation of each compound was shown to occur (75% or greater) under batch conditions with the mixed population. Actual wastes were tested by adding an aliquot to the media, determining the biomass increase, and monitoring the disappearance of the compounds. The compounds in actual waste were degraded, but at different rates than the batch cultures that did not have waste added. The potential of using bioprocessing methods for treating mixed wastes from biomedical research is discussed.

  6. VHF EPR determination of the chemical forms of organic sulfur in coal

    SciTech Connect

    Clarkson, R.B.

    1991-01-01

    This program addresses the need for innovative approaches to characterize the organic sulfur in Illinois Basin coals. We have developed a very high frequency electron paramagnetic resonance (EPR) spectrometer operating at the W-band of microwave frequencies (96 GHz). This instrument has shown unique sensitivity to heteroatoms in coal, and we believe the technique can be successfully applied for the non-destructive, direct determination of organic sulfur in coal. Preliminary data from Illinois coals and separated macerals indicate that the method also may be able to distinguish aromatic from aliphatic sulfur, and may be useful in assessing the extent of conjugation in aromatic portions of the coal. These high energy spectroscopic techniques, however invariably suffer from the fact that they are not truly non-destructive. By contrast, the low powers and relatively low energy radiation used in magnetic resonance techniques have virtually no effect on the physical structure or chemical composition of coal.

  7. [Emission characteristics and hazard assessment analysis of volatile organic compounds from chemical synthesis pharmaceutical industry].

    PubMed

    Li, Yan; Wang, Zhe-Ming; Song, Shuang; Xu, Zhi-Rong; Xu, Ming-Zhu; Xu, Wei-Li

    2014-10-01

    In this study, volatile organic compounds (VOCs) released from chemical synthesis pharmaceutical industry in Taizhou, Zhejiang province were analyzed quantitatively and qualitatively. The total volatile organic compounds (TVOCs) was in the range of 14.9-308.6 mg · m(-3). Evaluation models of ozone formation potentials (OFP) and health risk assessment were adopted to preliminarily assess the environmental impact and health risk of VOCs. The results showed that the values of OFP of VOCs were in the range of 3.1-315.1 mg · m(-3), based on the maximum incremental reactivity, the main principal contribution was toluene, tetrahydrofuran (THF), acetic ether etc. The non-carcinogenic risk and the carcinogen risk fell in the ranges of 9.48 x 10(-7)-4.98 x 10(-4) a(-1) and 3.17 x 10(-5)- 6.33 x 10(-3). The principal contribution of VOCs was benzene, formaldehyde and methylene chloride.

  8. Automated screening for small organic ligands using DNA-encoded chemical libraries.

    PubMed

    Decurtins, Willy; Wichert, Moreno; Franzini, Raphael M; Buller, Fabian; Stravs, Michael A; Zhang, Yixin; Neri, Dario; Scheuermann, Jörg

    2016-04-01

    DNA-encoded chemical libraries (DECLs) are collections of organic compounds that are individually linked to different oligonucleotides, serving as amplifiable identification barcodes. As all compounds in the library can be identified by their DNA tags, they can be mixed and used in affinity-capture experiments on target proteins of interest. In this protocol, we describe the screening process that allows the identification of the few binding molecules within the multiplicity of library members. First, the automated affinity selection process physically isolates binding library members. Second, the DNA codes of the isolated binders are PCR-amplified and subjected to high-throughput DNA sequencing. Third, the obtained sequencing data are evaluated using a C++ program and the results are displayed using MATLAB software. The resulting selection fingerprints facilitate the discrimination of binding from nonbinding library members. The described procedures allow the identification of small organic ligands to biological targets from a DECL within 10 d.

  9. Nonlinear and interactive effects in the sorption of hydrophobic organic chemicals by sediments

    SciTech Connect

    Jepsen, R.; Lick, W.

    1999-08-01

    Long-term experiments were done in order to investigate nonlinear isotherms and interactive effects in the sorption of hydrophobic organic chemicals (HOCs) by sediments. In the isotherm experiments, it was demonstrated that the isotherms for all HOCs tested were linear as long as the mass of the sorbed HOC was small by comparison with the mass of organic carbon in the sediments; for larger sorbed HOC concentrations, the isotherms were nonlinear. Sorption experiments also were done with hexachlorobenzene (HCB)-octanol, HCB-ethanol, octanol-ethanol, and HOC-methanol mixtures in water and sediments. Interactive effects were observed and can be described in terms of the partitioning of the primary HOC between the cosolvent, water, and sediments.

  10. Chemical and spectroscopic characterization of water extractable organic matter during vermicomposting of cattle dung.

    PubMed

    Lv, Baoyi; Xing, Meiyan; Yang, Jian; Qi, Wensheng; Lu, Yongsen

    2013-03-01

    This work illustrated the characteristics and transformation of water extractable organic matter (WEOM) during vermistabilization (Eisenia fetida) of cattle dung by means of chemical and spectroscopic methods. The independent experiment conducted in triplicate was sampled at the 0, 7, 14, 21, 35, 60 and 90days. Results showed that the DOC kept steady around 2.7gkg(-1) after day 60 and the DOC/DON ratio decreased from 19.77 to 5.26 till the end of vermicomposting. On the other hand, vermicomposting decreased the aliphatic, proteinaceous, carbohydrates components and increased the aromaticity and oxygen-containing functional groups in the WEOM. Moreover, fluorescence spectra and fluorescence regional integration (FRI) results indicated that protein-like groups were degraded and fulvic and humic acid-like compounds were evolved during the vermicomposting process. In all, this study suggested the suitability of WEOM for monitoring the organics transformation and assessing the maturity in the vermicomposting.

  11. Reducing health risk assigned to organic emissions from a chemical weapons incinerator.

    PubMed

    Laman, David M; Weiler, B Douglas; Skeen, Rodney S

    2013-03-01

    Organic emissions from a chemical weapons incinerator have been characterized with an improved set of analytical methods to reduce the human health risk assigned to operations of the facility. A gas chromatography/mass selective detection method with substantially reduced detection limits has been used in conjunction with scanning electron microscopy/energy dispersive X-ray spectrometry and Fourier transform infrared microscopy to improve the speciation of semi-volatile and non-volatile organics emitted from the incinerator. The reduced detection limits have allowed a significant reduction in the assumed polycyclic aromatic hydrocarbon (PAH) and aminobiphenyl (ABP) emission rates used as inputs to the human health risk assessment for the incinerator. A mean factor of 17 decrease in assigned human health risk is realized for six common local exposure scenarios as a result of the reduced PAH and ABP detection limits.

  12. Self-Organized Stationary Patterns in Networks of Bistable Chemical Reactions.

    PubMed

    Kouvaris, Nikos E; Sebek, Michael; Mikhailov, Alexander S; Kiss, István Z

    2016-10-10

    Experiments with networks of discrete reactive bistable electrochemical elements organized in regular and nonregular tree networks are presented to confirm an alternative to the Turing mechanism for the formation of self-organized stationary patterns. The results show that the pattern formation can be described by the identification of domains that can be activated individually or in combinations. The method also enabled the localization of chemical reactions to network substructures and the identification of critical sites whose activation results in complete activation of the system. Although the experiments were performed with a specific nickel electrodissolution system, they reproduced all the salient dynamic behavior of a general network model with a single nonlinearity parameter. Thus, the considered pattern-formation mechanism is very robust, and similar behavior can be expected in other natural or engineered networked systems that exhibit, at least locally, a treelike structure.

  13. Organization of Biomedical Data for Collaborative Scientific Research: A Research Information Management System

    PubMed Central

    Myneni, Sahiti; Patel, Vimla L.

    2010-01-01

    Biomedical researchers often work with massive, detailed and heterogeneous datasets. These datasets raise new challenges of information organization and management for scientific interpretation, as they demand much of the researchers’ time and attention. The current study investigated the nature of the problems that researchers face when dealing with such data. Four major problems identified with existing biomedical scientific information management methods were related to data organization, data sharing, collaboration, and publications. Therefore, there is a compelling need to develop an efficient and user-friendly information management system to handle the biomedical research data. This study evaluated the implementation of an information management system, which was introduced as part of the collaborative research to increase scientific productivity in a research laboratory. Laboratory members seemed to exhibit frustration during the implementation process. However, empirical findings revealed that they gained new knowledge and completed specified tasks while working together with the new system. Hence, researchers are urged to persist and persevere when dealing with any new technology, including an information management system in a research laboratory environment. PMID:20543892

  14. EPA/NSF ETV Equipment Verification Testing Plan for the Removal of Volatile Organic Chemical Contaminants by Adsorptive Media Processes

    EPA Science Inventory

    This document is the Environmental Technology Verification (ETV) Technology Specific Test Plan (TSTP) for evaluation of drinking water treatment equipment utilizing adsorptive media for synthetic organic chemical (SOC) removal. This TSTP is to be used within the structure provid...

  15. Recent Topics in Chemical and Clinical Research on Glycated Albumin

    PubMed Central

    Ueda, Yuki; Matsumoto, Hideyuki

    2015-01-01

    The measuring method for glycated albumin (GA) has been developed as a new glycemic control marker since the beginning of the 21st century. Since GA has an advantage in reflecting glycemic status over a shorter period than hemoglobin A1c (HbA1c), much research and many reviews have been reported. However, so far there have been few reports on glycation sites based on the tertiary structure of human serum albumin (HSA) and the comparison of glycation rates between GA and HbA1c in detail. The present review discusses how the glycation sites of lysine residues in HSA are modified with glucose, whereas the glycation sites of lysine residues are located inside of HSA as well as the direct comparison of glycation rates between GA and HbA1c using human blood. Moreover, the most recent clinical researches on GA are described. PMID:25614014

  16. The prisoner as model organism: malaria research at Stateville Penitentiary

    PubMed Central

    Comfort, Nathaniel

    2009-01-01

    In a military-sponsored research project begun during the Second World War, inmates of the Stateville Penitentiary in Illinois were infected with malaria and treated with experimental drugs that sometimes had vicious side effects. They were made into reservoirs for the disease and they provided a food supply for the mosquito cultures. They acted as secretaries and technicians, recording data on one another, administering malarious mosquito bites and experimental drugs to one another, and helping decide who was admitted to the project and who became eligible for early parole as a result of his participation. Thus, the prisoners were not simply research subjects; they were deeply constitutive of the research project. Because a prisoner’s time on the project was counted as part of his sentence, and because serving on the project could shorten one’s sentence, the project must be seen as simultaneously serving the functions of research and punishment. Michel Foucault wrote about such ‘mixed mechanisms’ in his Discipline and punish. His shining example of such a ‘transparent’ and subtle style of punishment was the panopticon, Jeremy Bentham’s architectural invention of prison cellblocks arrayed around a central guard tower. Stateville prison was designed on Bentham’s model; Foucault featured it in his own discussion. This paper, then, explores the power relations in this highly idiosyncratic experimental system, in which the various roles of model organism, reagent, and technician are all occupied by sentient beings who move among them fluidly. This, I argue, created an environment in the Stateville hospital wing more panoptic than that in the cellblocks. Research and punishment were completely interpenetrating, and mutually reinforcing. PMID:19720327

  17. Life cycle risks for human health: a comparison of petroleum versus bio-based production of five bulk organic chemicals.

    PubMed

    Roes, Alexander L; Patel, Martin K

    2007-10-01

    This article describes the development and application of a generic approach to the comparative assessment of risks related to the production of organic chemicals by petrochemical processes versus white biotechnology. White biotechnology, also referred to as industrial biotechnology, typically uses bio-based feedstocks instead of the fossil raw materials used in the petrochemical sector. The purpose of this study was to investigate whether the production of chemicals by means of white biotechnology has lower conventional risks than their production by petrochemical processes. Conventional risks are the risks of well-established processes, and not those related to genetically modified microorganisms and plants. Our approach combines classical risk assessment methods (largely based on toxicology), as developed by the life cycle assessment (LCA) community, with statistics on technological disasters, accidents, and work-related illnesses. Moreover, it covers the total process chain for both petrochemical and bio-based products from cradle to grave. The approach was applied to five products: the plastics polytrimethylene terephthalate (PTT), polyhydroxyalkanoates (PHA), polyethylene terephthalate (PET), polyethylene (PE), and ethanol. Our results show that the conventional risks related to the white biotechnology products studied are lower than those of the petrochemical products. However, considering the uncertainties with respect to the ranges of input data, the (incomplete) coverage of emissions by the environmental priority strategies (EPS) 2000 method, and the uncertainties of the assumptions made in this study (i.e., large to very large), the differences in results between bio-based and petrochemical products fall into the uncertainty range. Because of this, future research is necessary to decrease the uncertainties before we can conclude that the conventional risks of biotechnologically produced chemicals are lower than those of fossil-fuel-derived chemicals.

  18. Organic honey from Trás-Os-Montes region (Portugal): chemical, palynological, microbiological and bioactive compounds characterization.

    PubMed

    Estevinho, Leticia M; Feás, Xesús; Seijas, Julio A; Pilar Vázquez-Tato, M

    2012-02-01

    At the present time, the quality, integrity, sanitation and nutritional value of honeys receive attention on an international level due to the increasing content of chemicals in the aforementioned matrix. This work was conducted to evaluate the quality of 75 organic honey samples from the Trás-Os-Montes region (Portugal). Mean values obtained for physico-chemical parameters were: pH 3.7; 15.6% moisture; 0.26mS/cm electrical conductivity; 0.25% ash; 1.1mg/kg HMF; 15.3 Gothe diastase activity; 40.3meq/kg free acidity; 67.8% invert sugars and 2.7% apparent sucrose. All honey samples can be classified as monofloral Erica sp., as showed by pollen features. The amounts of phenols and flavonoids in the samples were also determined. In respect to sanitary quality (fecal coliforms) and safety (sulfite-reducing clostridia and Salmonella), all organic honey samples were negative. Furthermore, yeast and molds were detected in low counts, with mean values obtained of 5.5cfu/g and the value of total aerobic mesophiles obtained from honeys was established in 1.3×10(2)cfu/g±7.5×10(1)cfu/g. The levels of flavonoids had a stronger impact on both mesophiles (p=0.0004) and molds (p=0.0138) than the sucrose concentration (p=0.001 and 0.0278; respectively). The results reported in this study should be introduced in the organic honey label, and may help beekeepers, the industry, researchers and consumers better understand honey properties.

  19. Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

    PubMed Central

    Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

    2016-01-01

    Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V. PMID:27966605

  20. Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

    NASA Astrophysics Data System (ADS)

    Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

    2016-12-01

    Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V.