Science.gov

Sample records for chemical research organic

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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)

  7. Quantitative Research in Chemical Education.

    ERIC Educational Resources Information Center

    Nurrenbern, Susan C.; Robinson, William R.

    1994-01-01

    Provides an overview of the area of quantitative research in chemical education, which involves the same components that comprise chemical research: (1) a question or hypothesis; (2) research design; (3) data collection and analysis; and (4) interpretation of results. Includes questions of interest to chemical educators; areas of quantitative…

  8. 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.

  9. Research as Chemical Education.

    ERIC Educational Resources Information Center

    Doyle, Michael P.

    1984-01-01

    Discusses: (1) the conflict about the importance of research at predominantly undergraduate schools; (2) sources of funding for undergraduate research (several of which are targeted at predominantly undergraduate institutions); and (3) undergraduate research at doctoral-granting institutions. (JN)

  10. Acute toxicity handbook of chemicals to estuarine organisms

    SciTech Connect

    Mayer, F.L.

    1987-04-01

    All acute toxicity data developed by the Gulf Breeze Environmental Research Laboratory, U.S. Environmental Protection Agency, since 1961 were evaluated for quality. A data base was established for 1175 tests with 197 chemicals and 52 species of estuarine organisms. The chemicals represent all major groups of pesticides, as well as numerous industrial and inorganic chemicals.

  11. Organizing research data

    PubMed Central

    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. PMID:21999359

  12. 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...

  13. 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)

  14. 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.

  15. 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.

  16. 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. PMID:20549466

  17. 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.

  18. 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...

  19. Chemically crosslinked isoreticular metal-organic frameworks.

    PubMed

    Allen, Corinne A; Boissonnault, Jake A; Cirera, Jordi; Gulland, Ryan; Paesani, Francesco; Cohen, Seth M

    2013-04-21

    Herein we report the synthesis of canonical isoreticular metal-organic frameworks (IRMOFs) containing interligand crosslinks. Chemically crosslinking two molecules of 2-amino-1,4-benzene dicarboxylic acid (NH2-BDC) gives ligands that readily form IRMOF-1 analogs, producing crosslinked MOFs that may be designed to have novel properties.

  20. [Comparative research on determination of water integrated organic pollution index with three dimensional excitation-emission fluorescence spectroscopy and traditional wet chemical methods].

    PubMed

    Wang, Zhi-gang; Liu, Wen-qing; Zhang, Yu-jun; Li, Hong-bin; Zhao, Nan-Jing; Liu, Jian-guo; Sima, Wei-chang; Yang, Li-shu

    2007-12-01

    Three dimensional excitation-emission fluorescence spectra, chemical oxygen demanding (COD) and dissolved organic carbon (DOC) for water samples from Science Island, Chaohu Lake and Taihu Lake were determined. The COD values of the samples from Chaohu Lake were linearly correlated with the DOC values. Relationships of dissolved organic matter (DOM) concentrations determined by three dimensional excitation-emission fluorescence matrix (3DEEM), observed protein-like fluorescence intensity (Ipro-like) and humic-like fluorescence intensity (Ihum-like) to the chemical oxygen Demanding (COD) for all the samples from different sources were analyzed. Results indicated that DOM concentrations measured by 3DEEM and COD for the water samples from Science Island were well linearly related (r = 0.82172), and the linear relationships also existed between Ipro-like. and COD (r = 0.84651), as well as Ihum-like and COD (r = 0.83689). However, for the water samples from Chaohu Lake and Taihu Lake, no linear relationships existed. The cause of the above difference between the water samples from Science Island and those from Chaohu Lake and Taihu Lake, and the feasibility and the limits of the integrated organic pollution measurement using three dimensional excitation-emission fluorescence spectroscopy were further discussed.

  1. 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.

  2. Early chemical development at Legacy Wyeth Research.

    PubMed

    O'Brien, Michael K; Kolb, Michael; Connolly, Terrence J; McWilliams, J Christopher; Sutherland, Karen

    2011-01-01

    This article describes an approach to early process development in the context of the productivity model in legacy Wyeth (i.e. to deliver two New Drug Applications per year for New Molecular Entities). As a result of the model, the cycle time from lead selection to phase I decreased and the number of compounds in early development increased. In response, Wyeth Chemical Development devised a resource-neutral approach to early process development, which is described here. This model harvested synergies from integrating advanced technologies and aggressive sourcing with a matrix research organization and efficient ways of working. It provided a model that met the business needs of our former organization while ensuring the timely delivery of high-quality active pharmaceutical ingredients and safe, scalable processes. PMID:21111844

  3. Managing the Organized Research Unit.

    ERIC Educational Resources Information Center

    Friedman, Robert S.; Friedman, Renee C.

    1984-01-01

    Organized research units, a nondepartmental structure for industry-sponsored university research administration, are attractive vehicles. They support high-risk ventures, encourage faculty recruitment and retention, consolidate resources, provide a forum for interdisciplinary or multidisciplinary exchange, offer graduate study opportunities,…

  4. TMVOC, simulator for multiple volatile organic chemicals

    SciTech Connect

    Pruess, Karsten; Battistelli, Alfredo

    2003-03-25

    TMVOC is a numerical simulator for three-phase non-isothermal flow of water, soil gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. It is an extension of the TOUGH2 general-purpose simulation program developed at the Lawrence Berkeley National Laboratory. TMVOC is designed for applications to contamination problems that involve hydrocarbon fuel or organic solvent spills in saturated and unsaturated zones. It can model contaminant behavior under ''natural'' environmental conditions, as well as for engineered systems, such as soil vapor extraction, groundwater pumping, or steam-assisted source remediation. TMVOC is upwards compatible with T2VOC (Falta et al., 1995) and can be initialized from T2VOC-style initial conditions. The main enhancements in TMVOC relative to T2VOC are as follows: a multicomponent mixture of volatile organic chemicals can be modeled; any and all combinations of the three phases water-oil-gas are treated; several non-condensible gases may be present; diffusion is treated in all phases in a manner that is fully coupled with phase partitioning. This paper gives a brief summary of the methodology used in TMVOC as well as highlighting some implementation issues. Simulation of a NAPL spill and subsequent remediation is discussed for a 2-D vertical section of a saturated-unsaturated flow problem.

  5. 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.

  6. Using chemical organization theory for model checking

    PubMed Central

    Kaleta, Christoph; Richter, Stephan; Dittrich, Peter

    2009-01-01

    Motivation: The increasing number and complexity of biomodels makes automatic procedures for checking the models' properties and quality necessary. Approaches like elementary mode analysis, flux balance analysis, deficiency analysis and chemical organization theory (OT) require only the stoichiometric structure of the reaction network for derivation of valuable information. In formalisms like Systems Biology Markup Language (SBML), however, information about the stoichiometric coefficients required for an analysis of chemical organizations can be hidden in kinetic laws. Results: First, we introduce an algorithm that uncovers stoichiometric information that might be hidden in the kinetic laws of a reaction network. This allows us to apply OT to SBML models using modifiers. Second, using the new algorithm, we performed a large-scale analysis of the 185 models contained in the manually curated BioModels Database. We found that for 41 models (22%) the set of organizations changes when modifiers are considered correctly. We discuss one of these models in detail (BIOMD149, a combined model of the ERK- and Wnt-signaling pathways), whose set of organizations drastically changes when modifiers are considered. Third, we found inconsistencies in 5 models (3%) and identified their characteristics. Compared with flux-based methods, OT is able to identify those species and reactions more accurately [in 26 cases (14%)] that can be present in a long-term simulation of the model. We conclude that our approach is a valuable tool that helps to improve the consistency of biomodels and their repositories. Availability: All data and a JAVA applet to check SBML-models is available from http://www.minet.uni-jena.de/csb/prj/ot/tools Contact: dittrich@minet.uni-jena.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19468053

  7. 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.

  8. A critical review and evaluation of bioproduction of organic chemicals

    SciTech Connect

    Leeper, S.A.; Andrews, G.F.

    1991-12-31

    Dependence on petroleum as the primary feedstock for production of chemicals cannot continue indefinitely. Bioconversion could provide an alternate route to production of organic chemicals. A wide range of commodity chemicals and potentially new chemicals can be produced via bioconversion of biomass. However, before large-scale bioproduction of organic chemicals become a reality issues related to economics, feedstock availability, environment, and energy requirements must be addressed. In this paper, these issues are discussed, and promising potential candidates for bioproduction are identified.

  9. 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

  10. Adsorption of organic chemicals in soils.

    PubMed

    Calvet, R

    1989-11-01

    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.

  11. Observations on the Organization of Social Research.

    ERIC Educational Resources Information Center

    Rossi, Peter H.

    The organization of social research is discussed. Attention is directed to the following concerns: the forces that foster organizations of research into centers and institutes and the informal organization of research into collaborative efforts; the forms taken by research organizations in the present and the advantages/disadvantages of each form…

  12. Radiation, chemicals, and occupational health research

    SciTech Connect

    Turner, J.E.

    1984-01-01

    Radiation protection and its interplay with physical research programs are described. Differences and similarities between problems in health protection for chemicals and for radiation are discussed. The importance of dosimetry in radiation work and its relevance to chemicals are cited. A collaborative program between physical and biological scientists on the toxicity of metals is briefly described. It serves as an example of new research directed toward the development of fundamental concepts and principles as a basis for understanding and controlling occupational and population exposures to chemicals. 12 references, 4 figures.

  13. The Generation of an Organic Inverted Chemical Garden.

    PubMed

    Pampalakis, Georgios

    2016-05-10

    A chemical garden based on iron salt that grows in organic solvents and ions is demonstrated for the first time. This prototype chemical garden develops in an inverted orientation, thus providing evidence that downward growth is feasible.

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. Chemical probing of glycans in cells and organisms.

    PubMed

    Rouhanifard, Sara H; Nordstrøm, Lars Ulrik; Zheng, Tianqing; Wu, Peng

    2013-05-21

    Among the four major building blocks of life, glycans play essential roles in numerous physiological and pathological processes. Due to their non-templated biosynthesis, advances towards elucidating the molecular details of glycan functions are relatively slow compared with the pace of protein and nucleic acid research. Over the past 30 years, chemical tools have emerged as powerful allies to genetics and molecular biology in the study of glycans in their native environment. This tutorial review will provide an overview of the recent technological developments in the field, as well as the progress in the application of these techniques to probe glycans in cells and organisms.

  19. Elimination kinetic model for organic chemicals in earthworms.

    PubMed

    Dimitrova, N; Dimitrov, S; Georgieva, D; Van Gestel, C A M; Hankard, P; Spurgeon, D; Li, H; Mekenyan, O

    2010-08-15

    Mechanistic understanding of bioaccumulation in different organisms and environments should take into account the influence of organism and chemical depending factors on the uptake and elimination kinetics of chemicals. Lipophilicity, metabolism, sorption (bioavailability) and biodegradation of chemicals are among the important factors that may significantly affect the bioaccumulation process in soil organisms. This study attempts to model elimination kinetics of organic chemicals in earthworms by accounting for the effects of both chemical and biological properties, including metabolism. The modeling approach that has been developed is based on the concept for simulating metabolism used in the BCF base-line model developed for predicting bioaccumulation in fish. Metabolism was explicitly accounted for by making use of the TIMES engine for simulation of metabolism and a set of principal transformations. Kinetic characteristics of transformations were estimated on the basis of observed kinetics data for the elimination of organic chemicals from earthworms. PMID:20185163

  20. 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.

  1. Chemical reactions of organic compounds on clay surfaces

    SciTech Connect

    Soma, Yuko; Soma, Mitsuyuki )

    1989-11-01

    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 Broensted or Lewis acidity of clay minerals.

  2. 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 ...

  3. 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…

  4. 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...

  5. 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...

  6. 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…

  7. 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

  8. 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)

  9. Philosophical Confusion in Chemical Education Research

    NASA Astrophysics Data System (ADS)

    Scerri, Eric R.

    2003-05-01

    The reputation of chemical education research among mainstream chemists is in need of improvement. This paper makes the claim that the present state of affairs is partly the result of the careless use of philosophical terms such as constructivism, behaviorism, and relativism. The relevance of these developments to the Science Wars debate is briefly examined, and some positive recommendations are proposed to remedy the situation.

  10. 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...

  11. 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...

  12. 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...

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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...

  18. 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.

  19. 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,

  20. 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. ...

  1. Combined chemical and microbiological removal of organic sulfur from coal

    SciTech Connect

    Raphaelian, L.A.

    1991-01-01

    The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.

  2. Advance Organizer Research: One Step Further.

    ERIC Educational Resources Information Center

    Zeitoun, Hassan Hussein

    The purpose of this paper is to: (1) explore some possible explanations for the lack of empirical support of advance organizers; (2) suggest a plan for improving the empirical research on advance organizers; and (3) recommend some further investigations needed in the area of advance organizers. Some explanations for this lack of support are…

  3. 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...

  4. 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.

  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. 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.

  7. International energy: Research organizations, 1986 - 1990

    NASA Astrophysics Data System (ADS)

    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 and 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.

  8. 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.

  9. 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.

  10. 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. PMID:26230485

  11. Ethical guidelines to publication of chemical research. American Chemical Society.

    PubMed

    1994-01-01

    The guidelines embodied in this document were revised by the editors of the Publication Division of the American Chemical Society in January 1994 and endorsed by the Society Committee on Publications.

  12. 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. PMID:26188793

  13. 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.

  14. Chemical, thermal and mechanical stabilities of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Howarth, Ashlee J.; Liu, Yangyang; Li, Peng; Li, Zhanyong; Wang, Timothy C.; Hupp, Joseph T.; Farha, Omar K.

    2016-03-01

    The construction of thousands of well-defined, porous, metal-organic framework (MOF) structures, spanning a broad range of topologies and an even broader range of pore sizes and chemical functionalities, has fuelled the exploration of many applications. Accompanying this applied focus has been a recognition of the need to engender MOFs with mechanical, thermal and/or chemical stability. Chemical stability in acidic, basic and neutral aqueous solutions is important. Advances over recent years have made it possible to design MOFs that possess different combinations of mechanical, thermal and chemical stability. Here, we review these advances and the associated design principles and synthesis strategies. We focus on how these advances may render MOFs effective as heterogeneous catalysts, both in chemically harsh condensed phases and in thermally challenging conditions relevant to gas-phase reactions. Finally, we briefly discuss future directions of study for the production of highly stable MOFs.

  15. 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.

  16. 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.

  17. The vomeronasal organ and chemical sensitivity: a hypothesis.

    PubMed

    Greene, Glenn J; Kipen, Howard M

    2002-08-01

    Environmental exposures to very low levels of airborne chemicals are associated with adverse symptoms, often affecting multiple organ systems, in the phenomenon of chemical sensitivity (CS). Recent surveys suggest a significant prevalence of chemically sensitive subjects in the United States, but the mechanism linking exposure to symptoms remains unclear, despite the advancement of a variety of theoretical models. In many of these models, exposure of the nasal respiratory system to an airborne agent is the first step in the pathway leading to symptoms. In this article, we advance the hypothesis that interactions between environmental chemicals and the vomeronasal organ (VNO) may play a role in the etiology of CS. The VNO, a bilateral, tubular organ located in the nose, serves in animals as part of a sensitive chemosensory system; however, evidence suggesting that the VNO retains a functional role in the adult human is controversial. Reported characteristics of the human VNO relevant to CS, including location, prevalence, selective sensitivity to airborne chemical exposure, and capacity to produce systemic effects, are discussed within the context of this ongoing debate. Beyond relevance to CS, the demonstration of an active, adult VNO could have significant impact on environmental toxicology.

  18. The vomeronasal organ and chemical sensitivity: a hypothesis.

    PubMed Central

    Greene, Glenn J; Kipen, Howard M

    2002-01-01

    Environmental exposures to very low levels of airborne chemicals are associated with adverse symptoms, often affecting multiple organ systems, in the phenomenon of chemical sensitivity (CS). Recent surveys suggest a significant prevalence of chemically sensitive subjects in the United States, but the mechanism linking exposure to symptoms remains unclear, despite the advancement of a variety of theoretical models. In many of these models, exposure of the nasal respiratory system to an airborne agent is the first step in the pathway leading to symptoms. In this article, we advance the hypothesis that interactions between environmental chemicals and the vomeronasal organ (VNO) may play a role in the etiology of CS. The VNO, a bilateral, tubular organ located in the nose, serves in animals as part of a sensitive chemosensory system; however, evidence suggesting that the VNO retains a functional role in the adult human is controversial. Reported characteristics of the human VNO relevant to CS, including location, prevalence, selective sensitivity to airborne chemical exposure, and capacity to produce systemic effects, are discussed within the context of this ongoing debate. Beyond relevance to CS, the demonstration of an active, adult VNO could have significant impact on environmental toxicology. PMID:12194902

  19. 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.

  20. UPTAKE OF IONIZABLE ORGANIC CHEMICALS AT FISH GILLS

    EPA Science Inventory

    Uptake of organic acids by fish, and their toxicity, generally decrease with increasing pH above the pK, presumably due to neutral forms of such chemicals being more readily adsorbed than their ionized forms. However, uptake usually exceeds that expected based just on the concent...

  1. Salt-water organisms may yield chemicals. [Dunalilla

    SciTech Connect

    Not Available

    1981-01-28

    The harvesting of suspended cyanobacteria and algae that grow in saline water is being studied by Ecoenergetics. The organisms are promising sources of lipids, glycerol, polysaccharides and carotenoids. Israel already has a pilot plant in operation which harvests the green alga, Dunalilla, by centrifuging and chemical treatments.

  2. 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.

  3. Fate of synthetic organic chemicals in soil-groundwater systems.

    PubMed

    Pancorbo, O C; Varney, T C

    1986-04-01

    Land disposal of municipal, industrial and agricultural wastes often leads to soil and groundwater contamination with synthetic organic chemicals. In this review, the fate of such organics in soils and the subsurface environment is discussed. In particular, the biodegradation of organic compounds in soils and the subsurface region, as well as the sorption of these compounds to soils is emphasized. Due to the disastrous impact of groundwater contamination on a community and the great cost of restoring a contaminated aquifer, a case is made for concentrating future efforts on isolating potential sources of groundwater contamination and instituting appropriate control measures.

  4. Organic crop production's top research priority: Pestiphytology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pestiphytology is the study of pest plants, commonly referred to as weeds. In a recent national survey, weed research was designated as the top research priority by organic producers. Manual weed control is a costly practice that can quickly decrease return on investment, while the absence of weed...

  5. 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.

  6. 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.

  7. 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…

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  13. 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

  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. 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...

  16. 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.

  17. 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.

  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. PMID:25774952

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

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

    PubMed

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

    2011-07-01

    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.

  5. Electronic Chemical Potentials of Porous Metal–Organic Frameworks

    PubMed Central

    2014-01-01

    The binding energy of an electron in a material is a fundamental characteristic, which determines a wealth of important chemical and physical properties. For metal–organic frameworks this quantity is hitherto unknown. We present a general approach for determining the vacuum level of porous metal–organic frameworks and apply it to obtain the first ionization energy for six prototype materials including zeolitic, covalent, and ionic frameworks. This approach for valence band alignment can explain observations relating to the electrochemical, optical, and electrical properties of porous frameworks. PMID:24447027

  6. 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

  7. 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.

  8. 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)

  9. A RESEARCH AGENDA FOR RISK MANAGEMENT OF ENDOCRINE DISRUPTING CHEMICALS

    EPA Science Inventory

    To date, research on suspected endocrine disrupting chemicals (EDCs) has focused on determining health effects in humans and wildlife and on occurrence of these chemicals in the environment. There is strong evidence that certain chemicals are causing endocrine-related effects in...

  10. High-Resolution Desorption Electrospray Ionization Mass Spectrometry for Chemical Characterization of Organic Aerosols

    SciTech Connect

    Laskin, Julia; Laskin, Alexander; Roach, Patrick J.; Slysz, Gordon W.; Anderson, Gordon A.; Nizkorodov, Serguei; Bones, David L.; Nguyen, Lucas

    2010-03-01

    Characterization of the chemical composition and chemical transformations of secondary organic aerosol (SOA) is both a major challenge and the area of greatest uncertainty in current aerosol research. This study presents the first application of desorption electrospray ionization combined with high-resolution mass spectrometry (DESI-MS) for detailed chemical characterization and studies of chemical aging of OA collected on Teflon substrates. DESI-MS offers unique advantages both for detailed characterization of chemically labile components in OA that cannot be detected using more traditional electrospray ionization mass spectrometry (ESI-MS) and for studying chemical aging of OA. DESI-MS enables rapid characterization of OA samples collected on substrates by eliminating the sample preparation stage. In addition, it enables detection and structural characterization of chemically labile molecules in OA samples by minimizing the residence time of analyte in the solvent. SOA produced by the ozonolysis of limonene (LSOA) was allowed to react with gaseous ammonia. Chemical aging resulted in measurable changes in the optical properties of LSOA observed using UV- visible spectroscopy. DESI-MS combined with tandem mass spectrometry experiments (MS/MS) enabled identification of species in aged LSOA responsible for absorption of the visible light. Detailed analysis of the experimental data allowed us to identify chemical changes induced by reactions of LSOA constituents with ammonia and distinguish between different mechanisms of chemical aging.

  11. MSW incinerator ash research to investigate chemical stabilization

    SciTech Connect

    Not Available

    1988-10-01

    The State University of New York (SUNY) at Stony Brook and a Texas company have teamed up to build huge tetrapods from garbage incineration ash. These concrete-like structures will be placed in Long Island Sound for a test of their stability. If proven successful, the test could lead to a new market for incinerator ash-shore protection devices for erosion control and artificial reefs. The New York State Center for Hazardous Waste Management SUNY at Buffalo approved a grant application submitted by the Waste Management Institute of the Marine Sciences Research Center for a two-year test of a chemical stabilization process currently being used for treatment of hazardous waste. The unique process, invented by HAZCON, Inc., Brookshire, Texas, chemically fixes heavy metals and produces a hardened, dense mass with extremely low permeabilities. Objectives of the research are to examine the leachate characteristic sand durability of the stabilized material. In addition, the work will evaluate the potential toxicity of the stabilized material to marine organisms.

  12. 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

  13. 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...

  14. 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...

  15. 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...

  16. 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…

  17. 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).

  18. Research proceedings on amphibian model organisms.

    PubMed

    Liu, Lu-Sha; Zhao, Lan-Ying; Wang, Shou-Hong; Jiang, Jian-Ping

    2016-07-18

    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

  19. 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

  20. 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.

  1. Undertaking Chemical Research at a Community College

    ERIC Educational Resources Information Center

    Brown, David R.

    2006-01-01

    The merits of involving undergraduates in research activities have been publicized in numerous reports and have been promoted through various programs. Moreover, the value of offering research experiences specifically to first and second year students has been lauded. Undergraduate research is generally accepted to be a vehicle through which…

  2. 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...

  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. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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....

  13. 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.

  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. Trophic Magnification of Organic Chemicals: A Global Synthesis.

    PubMed

    Walters, D M; Jardine, T D; Cade, B S; Kidd, K A; Muir, D C G; Leipzig-Scott, P

    2016-05-01

    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. PMID:27014905

  16. 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.

  17. 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.

  18. Chemically active organically doped sol-gel materials: enzymatic sensors, chemical sensors, and photoactive materials

    NASA Astrophysics Data System (ADS)

    Avnir, David; Braun, S.; Lev, Ovadia; Ottolenghi, M.

    1992-12-01

    Organically-doped porous sol-gel matrices of optical grade have evolved in recent years into a wide class of materials with diverse applications. We review recent progress made in our laboratories in three domains of applications: the trapping of enzymes with the consequent design of (e.g. glucose) sensors; the development of chemical sensors; and the design of photoactive material for (solar) light energy conversion.

  19. Predicting microbial toxicity of nonuniform multicomponent mixtures of organic chemicals

    SciTech Connect

    Peace, J.; Daniel, D.; Nirmalakhandan, N.; Egemen, E.

    1997-04-01

    Three schemes proposed in the literature for analyzing joint toxic effects of multicomponent mixtures on fish, namely the additivity index (AI), the mixture toxicity index (MTI), and the similarity parameter ({lambda}) are evaluated in this study for microbial toxicity. A new approach is proposed to establish acceptance limits for the similarity parameter, {lambda}, based on experimental errors and uncertainties. Quantitative structure activity relationship (QSAR) techniques are then used to develop a model to predict the concentrations of components in mixtures that would jointly cause 50% inhibition of microbial respiration. The application of this approach is demonstrated on the experimental toxicity data of six eight-component organic chemical mixtures on microorganisms.

  20. 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.

  1. 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

  2. Self organizing software research : LDRD final report.

    SciTech Connect

    Osbourn, Gordon Cecil

    2004-01-01

    We have made progress in developing a new statistical mechanics approach to designing self organizing systems that is unique to SNL. The primary application target for this ongoing research has been the development of new kinds of nanoscale components and hardware systems. However, this research also enables an out of the box connection to the field of software development. With appropriate modification, the collective behavior physics ideas for enabling simple hardware components to self organize may also provide design methods for a new class of software modules. Our current physics simulations suggest that populations of these special software components would be able to self assemble into a variety of much larger and more complex software systems. If successful, this would provide a radical (disruptive technology) path to developing complex, high reliability software unlike any known today. This high risk, high payoff opportunity does not fit well into existing SNL funding categories, as it is well outside of the mainstreams of both conventional software development practices and the nanoscience research area that spawned it. This LDRD effort was aimed at developing and extending the capabilities of self organizing/assembling software systems, and to demonstrate the unique capabilities and advantages of this radical new approach for software development.

  3. 40 CFR 455.20 - Applicability; description of the organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR 124.8. ... organic pesticide chemicals manufacturing subcategory. 455.20 Section 455.20 Protection of Environment... Organic Pesticide Chemicals Manufacturing Subcategory § 455.20 Applicability; description of the...

  4. 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.

  5. 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.

  6. 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.

  7. Trace organic chemicals contamination in ground water recharge.

    PubMed

    Díaz-Cruz, M Silvia; Barceló, Damià

    2008-06-01

    Population growth and unpredictable climate changes will pose high demands on water resources in the future. Even at present, surface water is certainly not enough to cope with the water requirement for agricultural, industrial, recreational and drinking purposes. In this context, the usage of ground water has become essential, therefore, their quality and quantity has to be carefully managed. Regarding quantity, artificial recharge can guarantee a sustainable level of ground water, whilst the strict quality control of the waters intended for recharge will minimize contamination of both the ground water and aquifer area. However, all water resources in the planet are threatened by multiple sources of contamination coming from the extended use of chemicals worldwide. In this respect, the environmental occurrence of organic micropollutants such as pesticides, pharmaceuticals, industrial chemicals and their metabolites has experienced fast growing interest. In this paper an overview of the priority and emerging organic micropollutants in the different source waters used for artificial aquifer recharge purposes and in the recovered water is presented. Besides, some considerations regarding fate and removal of such compounds are also addressed.

  8. 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.

  9. 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.

  10. 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.

  11. Improving Molecular Level Chemical Speciation of Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Worton, D. R.; Decker, M.; Isaacman, G. A.; Chan, A.; Wilson, K. R.; Goldstein, A. H.

    2013-12-01

    A substantial fraction of fine mode aerosols are organic with the majority formed in the atmosphere through oxidation of gas phase compounds emitted from a variety of natural and man-made sources. As a result, organic aerosols are comprised of thousands of individual organic species whose complexity increases exponentially with carbon number and degree of atmospheric oxidation. Chemical characterization of individual compounds present in this complex mixture provides information on sources and transformation processes that are critical for apportioning organic carbon from an often convoluted mixture of sources and to constrain oxidation mechanisms needed for atmospheric models. These compounds also affect the physical and optical properties of the aerosol but the vast majority remain unidentified and missing from published mass spectral libraries because of difficulties in separating and identifying them. We have developed improved methodologies for chemical identification in order to better understand complex environmental mixtures. Our approach has been to combine two-dimensional gas chromatography with high resolution time of flight mass spectrometry (GC×GC-HRTOFMS) and both traditional electron ionization (EI) and vacuum ultraviolet (VUV) photoionization. GC×GC provides improved separation of individual compounds over traditional one dimensional GC and minimizes co-elution of peaks resulting in mass spectra that are virtually free of interferences. VUV ionization is a ';soft' ionization technique that reduces fragmentation and enhances the abundance of the parent or molecular ion, which when combined with high resolution mass spectrometry can provide molecular formulas for chromatographic peaks. We demonstrate our methodology by applying it to identify more than 500 individual compounds in aerosol filter samples collected at Blodgett Forest, a rural site in the Sierra Nevada Mountains. Using the EI NIST mass spectral library and molecular formulas determined

  12. 40 CFR 455.20 - Applicability; description of the organic pesticide chemicals manufacturing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... organic pesticide chemicals manufacturing subcategory. 455.20 Section 455.20 Protection of Environment... Organic Pesticide Chemicals Manufacturing Subcategory § 455.20 Applicability; description of the organic pesticide chemicals manufacturing subcategory. (a) For the purpose of calculating and applying...

  13. 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...

  14. 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:...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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…

  20. 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 ...

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

    PubMed

    McNeill, V Faye

    2015-02-01

    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.

  2. 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.

  3. 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…

  4. Some consideration on potentials of coal organic materials for chemicals

    SciTech Connect

    Nomura, Masakatsu; Artok, Levent; Su, Yan; Murata, Satoru

    1998-12-31

    According to the recent structural studies on bituminous coals, the presence of condensed aromatic nuclei and alicyclic portion in coal is considered to be more abundant than believed so far. Based on these data consideration of the potential of coal for chemical production is made by referring to the results on sodium dichromate-oxidation of Akabira coal and detailed analysis of vacuum residue from Illinois No.6 coal derived liquid. It is also stressed that to select the appropriate coal samples for either flash pyrolysis or hydroliquefaction based on their detailed structural index is important to attain their effective conversion. Three methods occurs in the minds of coal chemists, pyrolysis, direct liquefaction and indirect liquefaction. In this paper, the authors focus on the former two methods because indirect liquefaction makes use of carbon monoxide and hydrogen obtained in coal gasification, being not fitted in the present context of potentials of coal organic materials.

  5. 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.

  6. Characterization of volatile organic chemical emissions from carpet cushions

    SciTech Connect

    Schaeffer, V.H.; Bhooshan, B.; Chen, S.B.; Sonenthal, J.S.; Hodgson, A.T.

    1996-09-01

    The U.S. Consumer Product Safety Commission is investigating chemical emissions from carpet systems in order to determine whether the emissions may be responsible for the numerous health complaints associated with carpet installation. As part of this effort, a study was conducted to identify and quantify volatile organic compounds (VOCs) released into the air by five major product types of new carpet cushions. Cushion samples were tested in small-volume dynamic chambers over a six-hour exposure period. Airborne VOCs collected on multisorbent samplers were identified using sensitive gas chromatography/mass spectrometry. A separate chamber method was developed to screen polyurethane cushions for emissions of toluene diisocyanates (TDI). Over 100 VOCs, spanning a broad range of chemical classes, were emitted from 17 carpet cushions. The pattern of emitted VOCs varied between and among product types, which reflects probable differences in manufacturing processes and ingredients. No significant quantities of TDI or formaldehyde were released by any cushions. Emission profiles were characterized for total VOCs and for the predominant individual VOCs. As a group, the synthetic fiber cushion samples emitted the lowest quantities of VOCs. Cushion samples purchased from carpet retailers released lesser amounts of VOCs than samples of the same cushion types obtained directly from the manufacturing mills. 11 refs., 2 figs., 3 tabs.

  7. QSAR for toxicity of organic chemicals to luminescent bacteria

    SciTech Connect

    Devillers, J.; Bintein, S.; Karcher, W.

    1994-12-31

    Over the last decade, there have been increasing pressures to review and reduce the use of laboratory animals for toxicity testing. For ethical and economic reasons, various techniques have been developed and proposed as potential alternatives for some of the whole animal toxicity assays. One assay proposed as an alternative to animal testing is the luminescent bacteria toxicity test, provided under the trade name of Microtox{reg_sign} test. This test has been widely used to estimate the toxicity of agricultural, pharmaceutical, and industrial chemicals producing a large amount of valuable toxicity results. Under these conditions, from a critical analysis of the literature, it has been possible to constitute a large data bank of more than 1,000 organic chemicals for deriving a general QSAR model for the Microtox test. Due to the heterogeneity of the data sets, the molecules were described by means of the modified autocorrelation method. The autocorrelation vectors were generated from atomic contributions encoding the hydrophobicity of the molecules. The validity of the model has been widely discussed and its implications in terms of hazard assessment have been also underlined.

  8. 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…

  9. 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.

  10. Modeling of the accumulation of organic lipophilic chemicals in earthworms

    SciTech Connect

    Belfroid, A.; Seinen, W.; Leeuwen, K. van; Hermens, J.; Gestel, K. van

    1994-12-31

    For aquatic and terrestrial species living in contaminated sediments and soils it is assumed that the major route of uptake of organic lipophilic compounds is by passive diffusion of the compound dissolved in the interstitial water. Dietary uptake will only be important for extremely lipophilic compounds with log K{sub ow} larger than 5--6. An accumulation study with earthworms in OECD artificial soil confirmed this hypothesis. However, the authors also observed dietary uptake in earthworms after feeding them with food contaminated with three chlorobenzenes, PCB153 and octachloronaphthalene. Still, the question remained whether dietary uptake is an important route of exposure. Therefore, a model was developed that, unlike for example the equilibrium partition theory, incorporates two routes of uptake. The model can be used to estimate the accumulation of inert organic chemicals with log Kow 2--7 in earthworms, but also to determine the relative contribution of the two routes of uptake to the total body burden. It will be shown that the relative contribution depends on the lipophilicity of the compound and also on the type of soil.

  11. Chemically engineered graphene-based 2D organic molecular magnet.

    PubMed

    Hong, Jeongmin; Bekyarova, Elena; de Heer, Walt A; Haddon, Robert C; Khizroev, Sakhrat

    2013-11-26

    Carbon-based magnetic materials and structures of mesoscopic dimensions may offer unique opportunities for future nanomagnetoelectronic/spintronic devices. To achieve their potential, carbon nanosystems must have controllable magnetic properties. We demonstrate that nitrophenyl functionalized graphene can act as a room-temperature 2D magnet. We report a comprehensive study of low-temperature magnetotransport, vibrating sample magnetometry (VSM), and superconducting quantum interference (SQUID) measurements before and after radical functionalization. Following nitrophenyl (NP) functionalization, epitaxially grown graphene systems can become organic molecular magnets with ferromagnetic and antiferromagnetic ordering that persists at temperatures above 400 K. The field-dependent, surface magnetoelectric properties were studied using scanning probe microscopy (SPM) techniques. The results indicate that the NP-functionalization orientation and degree of coverage directly affect the magnetic properties of the graphene surface. In addition, graphene-based organic magnetic nanostructures were found to demonstrate a pronounced magneto-optical Kerr effect (MOKE). The results were consistent across different characterization techniques and indicate room-temperature magnetic ordering along preferred graphene orientations in the NP-functionalized samples. Chemically isolated graphene nanoribbons (CINs) were observed along the preferred functionality directions. These results pave the way for future magnetoelectronic/spintronic applications based on promising concepts such as current-induced magnetization switching, magnetoelectricity, half-metallicity, and quantum tunneling of magnetization.

  12. Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)

    NASA Astrophysics Data System (ADS)

    Koppmann, R.; Hoffmann, T.; Kesselmeier, J.; Schatzmann, M.

    Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in Jülich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.

  13. 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.

  14. 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

  15. Research Progress on Chemical Constituents of Lonicerae japonicae flos.

    PubMed

    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.

  16. 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

  17. 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 Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of...

  18. 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 Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of...

  19. 15 CFR 740.11 - Governments, international organizations, and international inspections under the Chemical...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... organizations, and international inspections under the Chemical Weapons Convention (GOV). 740.11 Section 740.11... Governments, international organizations, and international inspections under the Chemical Weapons Convention... inspections under the Chemical Weapons Convention. (a) International safeguards—(1) Scope. You may export...

  20. Oxygenated Organic Chemicals in the Pacific Troposphere: Sources and Chemical Consequences

    NASA Astrophysics Data System (ADS)

    Chatfield, R. B.; Singh, H. B.; Fried, A.; Evans, M. J.; Jacob, D. J.; Blake, D.; Heikes, B.; Talbot, R. W.; Sachse, G. W.

    2002-12-01

    Airborne measurements of a large number of oxygenated organics were carried out in the Pacific troposphere (to 12 km) in the Spring of 2001 (Feb. 24-April 10). Gas chromatography measurements include acetaldehyde, propionaldehyde, acetone, methylethyl ketone, methanol, ethanol, PANs, and organic nitrates. Independent measurements of formaldehyde, peroxides, and tracers were simultaneously recorded. Highly polluted as well as surprisingly clean air masses were sampled. Oxygenated organics were abundant in the clean troposphere and were also greatly enhanced in the outflow regions from Asia. Carbonyls sequester NOx throughout the troposphere and are a reactive intermediate responsible for a large amount of formaldehyde. It is difficult to explain the large abundances of aldehydes in the background troposphere, and we examine the chemical repercussions of these high concentrations. In clean air, the reaction pathways from acetaldehyde to formaldehyde take more time, and this is reflected in a smaller sampled correlation of their concentrations. The atmospheric behavior of acetone, methylethyl ketone, and methanol is generally indicative of their common terrestrial sources. Including these observed high concentrations of aldehydes somewhats improve simulated HOx chemistry. These data are being analyzed statistically and with photochemical models and results will be presented, particularly as they describe source of the ubiquitous acetaldehyde.

  1. 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

  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. 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.

  4. 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

  5. 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.

  6. Clinical research in pediatric organ transplantation.

    PubMed

    Azeka, Estela; Saavedra, Laura Castillo; Fregni, Felipe

    2014-01-01

    Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments. PMID:24860862

  7. 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

  8. 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

  9. 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

  10. 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).

  11. 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. PMID:10412666

  12. 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

  13. 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

  14. 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

  15. 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...

  16. [Small compounds libraries: a research tool for chemical biology].

    PubMed

    Florent, Jean-Claude

    2013-01-01

    Obtaining and screening collections of small molecules remain a challenge for biologists. Recent advances in analytical techniques and instrumentation now make screening possible in academia. The history of the creation of such public or commercial collections and their accessibility is related. It shows that there is interest for an academic laboratory involved in medicinal chemistry, chemogenomics or "chemical biology" to organize its own collection and make it available through existing networks such as the French National chimiothèque or the European partner network "European Infrastructure of open screening platforms for Chemical Biology" EU-OpenScreen under construction.

  17. 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. ...

  18. 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.

  19. 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.

  20. Representative benthic bioindicator organisms for use in radiation effects research: Culture of Neanthes arenaceodentata (Polychaeta)

    SciTech Connect

    Harrison, F.L.; Knezovich, J.P.; Martinelli, R.E.

    1992-09-01

    The purpose of this document is to present a comprehensive synthesis of information pertaining to the selection and maintenance of bioindicator organisms for use in radiation-effects research. The focus of this report is on the benthic polychaete, Neanthes arenaceodentata, a species that has been used successfully at the Lawrence Livermore National Laboratory (LLNL) and other institutions to define the impacts of radiation and chemical toxicants on aquatic organisms. In this document, the authors provide a rationale for the selection of this organism, a description of its reproductive biology, and a description of the conditions that are required for the maintenance and rearing of the organism for use in toxicological research.

  1. 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

  2. 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.

  3. 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.

  4. Publication trends in model organism research.

    PubMed

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

    2014-11-01

    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.

  5. 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

  6. Research Planning and Organization in Sweden. Fact Sheets on Sweden.

    ERIC Educational Resources Information Center

    Swedish Inst., Stockholm.

    Swedish research policy and organization, research areas, university research institutes, and international research and development (R&D) cooperation are discussed. Swedish research policy may be characterized as sectorized, decentralized, and pluralistic. The governmental bodies responsible for research direction include the Ministry of…

  7. 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

  8. New hybrid organic-zincophosphate frameworks: single-crystal-to-single-crystal structural transformation and remarkable thermal and chemical stabilities.

    PubMed

    Chang, Tsung-Yuan; Yan, Zhao-Nan; Wang, Chun-Chi; Li, Hsing-Chun; Lin, Hsiu-Mei; Wang, Chih-Min

    2016-05-01

    This research is the first example of a hybrid metal phosphate that undergoes an SCSC structural transformation and provides a new route for the synthesis of organic-inorganic hybrid materials with high stabilities via the introduction of nitrogen-donor ligands into a metal-phosphate system. The synthesis, structural diversity, and thermal and chemical stabilities are also discussed.

  9. 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...

  10. 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 ...

  11. Adsorption mechanism of different organic chemicals on fluorinated carbon nanotubes.

    PubMed

    Li, Hao; Zheng, Nan; Liang, Ni; Zhang, Di; Wu, Min; Pan, Bo

    2016-07-01

    Multi-walled carbon nanotubes (MC) were fluorinated by a solid-phase reaction method using polytetrafluoroethylene (PTFE). The surface alteration of carbon nanotubes after fluorination (MC-F) was confirmed based on surface elemental analysis, TEM and SEM. The incorporation of F on MC surface was discussed as F incorporation on carbon defects, replacement of carboxyl groups, as well as surface coating of PTFE. The adsorption performance and mechanisms of MC-F for five kinds of representative organic compounds: sulfamethoxazole (SMX), ofloxacin (OFL), norfloxacin (NOR), bisphenol a (BPA) and phenanthrene (PHE) were investigated. Although BET-N2 surface area of the investigated CNTs decreased after fluorination, the adsorption of all five chemicals increased. Because of the glassification of MC-F surface coating during BET-N2 surface area measurement, the accessible surface area of MC-F was underestimated. Desorption hysteresis was generally observed in all the sorption systems in this study, and the desorption hysteresis of MC-F were stronger than the pristine CNTs. The enhanced adsorption of MC-F may be attributed the pores generated on the coated PTFE and the dispersed CNT aggregates due to the increased electrostatic repulsion after fluorination. The rearrangement of the bundles or diffusion of the adsorbates in MC-F inner pores were the likely reason for the strong desorption hysteresis of MC-F. The butterfly structure of BPA resulted in its high sorption and strong desorption hysteresis. The exothermic sorption character of OFL on CNTs resulted in its strong desorption hysteresis. PMID:27058918

  12. 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.

  13. [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.

  14. 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...

  15. 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.

  16. 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…

  17. 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.

  18. 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

  19. 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.

  20. 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…

  1. 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...

  2. 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...

  3. 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 ...

  4. Microfluidic chamber arrays for whole-organism behavior-based chemical screening†

    PubMed Central

    Srinivasan, Jagan; Sternberg, Paul W.; Gong, Emily; Schroeder, Frank C.; Lu, Hang

    2014-01-01

    The nematode Caenorhabditis elegans is an important model organism in genetic research and drug screening because of its relative simplicity, ease of maintenance, amenability to simple genetic manipulation, and relevance to human biology. However, their small size and mobility make nematodes difficult to physically manipulate, particularly with spatial and temporal precision. We have developed a microfluidic device to overcome these challenges and enable fast behavior-based chemical screening in C. elegans. The key components of this easy-to-use device allow rapid loading and housing of C. elegans in a chamber array for chemical screening. A simple two-step loading process enables simultaneous loading of a large number of animals within a few minutes without using any expensive/active off-chip components. In addition, chemicals can be precisely delivered to the worms and exchanged with high temporal precision. To demonstrate this feature and the ability to measure time dependent responses to chemicals, we characterize the transient response of worms exposed to different concentrations of anesthetics. We then use the device to study the effect of chemical signals from hermaphrodite worms on male behavior. The ability of the device to maintain a large number of free moving animals in one field of view over a long period of time permits us to demonstrate an increase in the incidence of a specific behavior in males subjected to worm-conditioned medium. Because our device allows monitoring of a large number of worms with single-animal resolution, we envision that this platform will greatly expedite chemical screening in C. elegans. PMID:21935539

  5. 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.

  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. PMID:24738471

  7. 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.

  8. 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. PMID:25416110

  9. Students' Understanding of Chemical Formulae: A review of empirical research

    NASA Astrophysics Data System (ADS)

    Taskin, Vahide; Bernholt, Sascha

    2014-01-01

    The fluent use of the chemical language is a major tool for successfully passing chemistry courses at school or university as well as for working as a chemist, since chemical formulae are both a descriptive and a heuristic tool. However, numerous studies have revealed remarkable difficulties of students with chemical formulae both at school and at university. Although analysed for decades, current studies and practical experiences indicate that the misinterpretation of symbolic representations by students is still an ongoing problem. This review intends not only to summarize but also to categorize students' problems and difficulties when dealing with chemical formulae as reported in empirical studies. For this purpose, two categories of descriptive character were deduced from the empirical data: the type of chemical formulae and the operational activities that were required in the tasks of the studies. All in all, 38 articles were analysed on the basis of these categories. Students' problems and difficulties are then reflected based on three main problem areas: language-based problems, problems due to conceptual understanding, and problems due to inadequate selection and interpretation of formulae. These three areas call for a broader perspective in the interpretation of students' problems and thus lead to a discussion of implications for further research and changes in teaching practice.

  10. 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.

  11. 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.

  12. Erroneous efficiency reports harm organic solar cell research

    NASA Astrophysics Data System (ADS)

    Zimmermann, Eugen; Ehrenreich, Philipp; Pfadler, Thomas; Dorman, James A.; Weickert, Jonas; Schmidt-Mende, Lukas

    2014-09-01

    Mischaracterization of solar cell power conversion efficiencies and widespread publication of inconsistent data in scientific journals threatens to undermine progress in organic and hybrid photovoltaics research.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. An Application of the Programmatic Organization Model to Applied Research.

    ERIC Educational Resources Information Center

    Haring, Norris G.; Krug, David A.

    Presented is a programatic organization model which is applied to research needs in special education. Major advantages of the model are given to be that of providing for several research activities which focus on one common problem, reducing the duplication of research effort, providing greater efficiency in use of research personnel and…

  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. 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. PMID:21956337

  2. Chemical reactions catalyzed by metalloporphyrin-based metal-organic frameworks.

    PubMed

    Nakagaki, Shirley; Ferreira, Gabriel Kaetan Baio; Ucoski, Geani Maria; Dias de Freitas Castro, Kelly Aparecida

    2013-06-21

    The synthetic versatility and the potential application of metalloporphyrins (MP) in different fields have aroused researchers' interest in studying these complexes, in an attempt to mimic biological systems such as cytochrome P-450. Over the last 40 years, synthetic MPs have been mainly used as catalysts for homogeneous or heterogeneous chemical reactions. To employ them in heterogeneous catalysis, chemists have prepared new MP-based solids by immobilizing MP onto rigid inorganic supports, a strategy that affords hybrid inorganic-organic materials. More recently, materials obtained by supramolecular assembly processes and containing MPs as building blocks have been applied in a variety of areas, like gas storage, photonic devices, separation, molecular sensing, magnets, and heterogeneous catalysis, among others. These coordination polymers, known as metal-organic frameworks (MOFs), contain organic ligands or complexes connected by metal ions or clusters, which give rise to a 1-, 2- or 3-D network. These kinds of materials presents large surface areas, Brønsted or redox sites, and high porosity, all of which are desirable features in catalysts with potential use in heterogeneous phases. Building MOFs based on MP is a good way to obtain solid catalysts that offer the advantages of bioinspired systems and zeolitic materials. In this mini review, we will adopt a historical approach to present the most relevant MP-based MOFs applicable to catalytic reactions such as oxidation, reduction, insertion of functional groups, and exchange of organic functions.

  3. 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.…

  4. 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.

  5. 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...

  6. (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...

  7. 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.

  8. 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.

  9. 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.

  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. 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.

  12. Real-time monitoring of volatile organic compounds using chemical ionization mass spectroscopy: Final report

    SciTech Connect

    Thornberg, S.M.; Mowry, C.D.; Keenan, M.R.; Bender, S.F.A.; Owen, T.

    1997-04-01

    Volatile organic compound (VOC) emission to the atmosphere is of great concern to semiconductor manufacturing industries, research laboratories, the public, and regulatory agencies. Some industries are seeking ways to reduce emissions by reducing VOCs at the point of use (or generation). This paper discusses the requirements, design, calibration, and use of a sampling inlet/quadrupole mass spectrometer system for monitoring VOCs in a semiconductor manufacturing production line. The system uses chemical ionization to monitor compounds typically found in the lithography processes used to manufacture semiconductor devices (e.g., acetone, photoresist). The system was designed to be transportable from tool to tool in the production line and to give the operator real-time feedback so the process(es) can be adjusted to minimize VOC emissions. Detection limits ranging from the high ppb range for acetone to the low ppm range fore other lithography chemicals were achieved using chemical ionization mass spectroscopy at a data acquisition rate of approximately 1 mass spectral scan (30 to 200 daltons) per second. A demonstration of exhaust VOC monitoring was performed at a working semiconductor fabrication facility during actual wafer processing.

  13. 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

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

    SciTech Connect

    Moriguchi, Ikuo; Hirono, Shuichi; Hirano, Hiroyuki

    1996-10-01

    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. 12 refs., 4 tabs.

  15. 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.

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

    PubMed

    Haggard, Brian E; Galloway, Joel M; Green, W Reed; Meyer, Michael 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). PMID:16738393

  17. 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.

  18. 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.

  19. Limited reversibility of bioconcentration of hydrophobic organic chemicals in phytoplankton.

    PubMed

    Koelmans, Albert A

    2014-07-01

    Aging, reversibility, and desorption rates for the binding of hydrophobic chemicals (HOC) to phytoplankton cells have not been directly measured. Here the effect of bioconcentration time on subsequent desorption of hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) was studied for the alga Monoraphidium minutum. Cell suspensions were exposed to HCB and PCBs spanning a range of log Kow values of 5.7 to 8.2, for 0.13 to 14 d. Subsequently, reversibility and desorption rates were assessed by extracting the chemicals from the cells using infinite sink extractions with Tenax beads or Empore disks employed in the cell suspension. Uptake was biphasic with constant relative contributions of fast surface sorption. Desorption was biphasic too and well fitted to a first order two compartment model. Increasing exposure times resulted in increasing slowly desorbing chemical fractions and decreased desorption rates from these fractions. For the most hydrophobic PCBs, slowly desorbing fractions were >80-90%, whereas desorption half-lives from these fractions ranged up to 120 days. The slow desorption rates directly prove that bioconcentration to algae can be rate limited and imply that already after a few hours of exposure, HOCs may become practically unavailable for repartitioning. PMID:24915281

  20. Activated persulfate for organic chemical degradation: A review.

    PubMed

    Matzek, Laura W; Carter, Kimberly E

    2016-05-01

    Activated persulfate reactions have widespread application for groundwater and environmental remediation, as many of these reactions involve destruction of environmental contaminants. Within the last five years, knowledge of activated persulfate degradation reactions has grown to include novel means of activating persulfate for enhanced removal of organic species. These current studies cover a long list of organic analytes, including pharmaceuticals, pesticides, halogenated compounds and dyes. An extensive review of recently published experimental parameters and results for the destruction of organic compounds via activated persulfate is presented. Focus is placed on emerging methodologies and manipulation of traditional activation techniques. Knowledge gaps are identified and discussed, as despite the number of publications on this subject, more broad-reaching guidelines are needed for optimizing applications of activated persulfate in water treatment.

  1. 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.

  2. Resolution of Redundant Semantic Type Assignments for Organic Chemicals in the UMLS

    PubMed Central

    Morrey, C. Paul; Chen, Ling; Halper, Michael; Perl, Yehoshua

    2011-01-01

    Objective The Unified Medical Language System (UMLS) integrates terms from different sources into concepts and supplements these with the assignment of one or more high-level semantic types (STs) from its Semantic Network (SN). For a composite organic chemical concept, multiple assignments of organic chemical STs often serve to enumerate the types of the composite’s underlying chemical constituents. This practice sometimes leads to the introduction of a forbidden redundant ST assignment, where both an ST and one of its descendants are assigned to the same concept. A methodology for resolving redundant ST assignments for organic chemicals, better capturing the essence of such composite chemicals than the typical omission of the more general ST, is presented. Methods and Material The typical SN resolution of a redundant ST assignment is to retain only the more specific ST assignment and omit the more general one. However, with organic chemicals, that is not always the correct strategy. A methodology for properly dealing with the redundancy based on the relative sizes of the chemical components is presented. It is more accurate to use the ST of the larger chemical component for capturing the category of the concept, even if that means using the more general ST. Results A sample of 254 chemical concepts having redundant ST assignments in older UMLS releases was audited to analyze the accuracy of current ST assignments. For 81 (32%) of them, our chemical analysis-based approach yielded a different recommendation from the UMLS (2009AA). New UMLS usage notes capturing rules of this methodology are proffered. Conclusions Redundant ST assignments have typically arisen for organic composite chemical concepts. A methodology for dealing with this kind of erroneous configuration, capturing the proper category for a composite chemical, is presented and demonstrated. PMID:21646001

  3. 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

  4. How can research organizations more effectively transfer research knowledge to decision makers?

    PubMed

    Lavis, John N; Robertson, Dave; Woodside, Jennifer M; McLeod, Christopher B; Abelson, Julia

    2003-01-01

    Five questions--What should be transferred to decision makers? To whom should it be transferred? By whom? How? With what effect?--provide an organizing framework for a knowledge transfer strategy. Opportunities for improving how research organizations transfer research knowledge can be found in the differences between the answers suggested by our understanding of the research literature and those provided by research-organization directors asked to describe what they do. In Canada, these opportunities include developing actionable messages for decision makers (only 30 percent of research organizations frequently or always do this), developing knowledge-uptake skills in target audiences and knowledge-transfer skills in research organizations (only 20 to 22 percent frequently or always do this), and evaluating the impact of knowledge-transfer activities (only 8 to 12 percent frequently or always conduct an evaluation). Research funders can help research organizations take advantage of these opportunities.

  5. NEEDED RESEARCH ON DIFFUSION WITHIN EDUCATIONAL ORGANIZATIONS.

    ERIC Educational Resources Information Center

    JAIN, NEMI C.; ROGERS, EVERETT M.

    IN SPITE OF THE VOLUME OF RESEARCH ATTENTION DEVOTED TO THE DIFFUSION OF INNOVATIONS, RELATIVELY LITTLE EMPHASIS HAS BEEN PLACED UPON DIFFUSION WITHIN ORGANIZATIONAL STRUCTURES. METHODOLOGICALLY, RELATIONAL ANALYSIS IN WHICH THE UNIT OF ANALYSIS IS A TWO-PERSON INTERACTING PAIR, A MULTIPLE PERSON COMMUNICATION CHAIN, OR CLIQUES OR SUBSYSTEMS IS…

  6. Chemical composition of dissolved organic nitrogen in the ocean

    NASA Astrophysics Data System (ADS)

    McCarthy, Matthew; Pratum, Tom; Hedges, John; Benner, Ronald

    1997-11-01

    Fixed nitrogen is one of the main limiting nutrients for primary production in the ocean, where it is biologically available in the form of dissolved inorganic and organic matter. Inorganic nitrogen concentrations are consequently very low in surface waters of temperate ocean gyres, yet fixed nitrogen persists in the form of dissolved organic matter. The small, rapidly cycling organic compounds fundamental to microbial and planktonic growth (such as free amino acids, amines and urea) account for only a minor fraction of total dissolved organic nitrogen (DON). In contrast, the vast majority of DON, especially in the deep ocean, resides in the form of nitrogenous substances that are resistant to biological degradation. These substances, which represent an enormous reservoir of fixed nitrogen, are not readily identified by conventional biochemical techniques, but have been assumed to consist largely of structurally complex macromolecules resulting from the degradation and spontaneous abiotic condensation of biochemical precursors. Here we present 15N NMR measurements that contradict this view. Our results show that most higher-molecular-weight DON in the ocean exists in amide form, rather than as a collection of nitrogen heterocycles that might be indicative of spontaneous condensation products. Because these amides are unlikely to form abiotically, the bulk of the ocean's DON reservoir appears to derive directly from degradation-resistant biomolecules.

  7. 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)

  8. Prediction of chemical biotransfer of organic chemicals from cattle diet into beef and milk using the molecular connectivity index

    SciTech Connect

    Dowdy, D.L.; Mckone, T.E.; Hsieh, D.P.H.

    1996-03-01

    Biotransfer factors (BTFs) represent the ratio of the concentration of a chemical found in animal tissues such as beef or milk to the animal`s daily intake of that chemical. Using currently available citations for BTFs in meat and milk, the use of molecular connectivity indices (MCIs) as a quantitative structure reactivity relationship (QSAR) for predicting the BTFs for organic chemicals is evaluated. Based on a statistical evaluation of correlation, residual error, and cross validation, this evaluation reveals that the MCI provides both higher reliability and a fast and cost-effective method for predicting the potential biotransfer of a chemical from environmental media into food. When compared to the use of K{sub ow} as a predictor of BTFs, the analysis here indicates that MCI can substantially increase the reliability with which BTFs can be estimated. 66 refs., 2 figs., 3 tabs.

  9. 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.

  10. 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).

  11. Chemical Sensitivity of the Sulfur K-Edge X-ray Absorption Spectra of Organic Disulfides.

    PubMed

    Pickering, Ingrid J; Barney, Monica; Cotelesage, Julien J H; Vogt, Linda; Pushie, M Jake; Nissan, Andrew; Prince, Roger C; George, Graham N

    2016-09-22

    Sulfur K-edge X-ray absorption spectroscopy increasingly is used as a tool to provide speciation information about the sulfur chemical form in complex samples, with applications ranging from fossil fuels to soil science to health research. As part of an ongoing program of systematic investigations of the factors that affect the variability of sulfur K near-edge spectra, we have examined the X-ray absorption spectra of a series of organic symmetric disulfide compounds. We have used polarized sulfur K-edge spectra of single crystals of dibenzyl disulfide to confirm the assignments of the major transitions in the spectrum as 1s → (S-S)σ* and 1s → (S-C)σ*. We also have examined the solution spectra of an extended series of disulfides and show that the spectra change in a systematic and predictable manner with the nature of the external group. PMID:27571342

  12. 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...

  13. 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 ...

  14. 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 ...

  15. 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...

  16. 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)

  17. Rapid method for isolating targeted organic chemicals from biological matrices

    SciTech Connect

    Caton, J.E.; Griest, W.H.; Watson, A.P.; Buchanan, M.V. ); Hazen, K.H. )

    1994-01-01

    The initial development is reported for a novel countercurrent filtration/dialysis and solid phase extractant system for the rapid isolation of low molecular weight target compounds from biological media. Except for piperazine (a highly water-soluble drug), recoveries of 50 - 95% were achieved for chemical warfare agent simulants and anthelmintic drugs extracted from meat, grain, or milk. The results suggest the potential for broad applications to complex samples such as environmental media and physiological specimens which traditionally require extensive fractionation prior to analysis.

  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. 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

  20. Self-organization and nanostructure formation in chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Walgraef, Daniel

    2013-10-01

    When thin films are grown on a substrate by chemical vapor deposition, the evolution of the first deposited layers may be described, on mesoscopic scales, by dynamical models of the reaction-diffusion type. For monatomic layers, such models describe the evolution of atomic coverage due to the combined effect of reaction terms representing adsorption-desorption and chemical processes and nonlinear diffusion terms that are of the Cahn-Hilliard type. This combination may lead, below a critical temperature, to the instability of uniform deposited layers. This instability triggers the formation of nanostructures corresponding to regular spatial variations of substrate coverage. Patterns wavelengths and symmetries are selected by dynamical variables and not by variational arguments. According to the balance between reaction- and diffusion-induced nonlinearities, a succession of nanostructures including hexagonal arrays of dots, stripes, and localized structures of various types may be obtained. These structures may initiate different growth mechanisms, including Volmer-Weber and Frank-Van der Merwe types of growth. The relevance of this approach to the study of deposited layers of different species is discussed.

  1. Self-organization and nanostructure formation in chemical vapor deposition.

    PubMed

    Walgraef, Daniel

    2013-10-01

    When thin films are grown on a substrate by chemical vapor deposition, the evolution of the first deposited layers may be described, on mesoscopic scales, by dynamical models of the reaction-diffusion type. For monatomic layers, such models describe the evolution of atomic coverage due to the combined effect of reaction terms representing adsorption-desorption and chemical processes and nonlinear diffusion terms that are of the Cahn-Hilliard type. This combination may lead, below a critical temperature, to the instability of uniform deposited layers. This instability triggers the formation of nanostructures corresponding to regular spatial variations of substrate coverage. Patterns wavelengths and symmetries are selected by dynamical variables and not by variational arguments. According to the balance between reaction- and diffusion-induced nonlinearities, a succession of nanostructures including hexagonal arrays of dots, stripes, and localized structures of various types may be obtained. These structures may initiate different growth mechanisms, including Volmer-Weber and Frank-Van der Merwe types of growth. The relevance of this approach to the study of deposited layers of different species is discussed. PMID:24229187

  2. 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.

  3. Microbial toxicity of mixtures of organic chemicals in soil medium-experimental protocol and modeling

    SciTech Connect

    Arulgnanendran, V.R.J.; Khandan, N.N.

    1995-12-31

    A laboratory procedure was developed to measure the microbial toxicity in soils using respirometric technique. The procedure was tested on 35 organic chemicals and several 8- and 10- component equitoxic mixtures. The chemicals assayed in this study were found to act jointly by simple addition. A modeling approach incorporating partitioning, sorption and Quantitative Structure Activity Relationship (QSAR) techniques was developed to estimate single chemical and mixture toxicity. This modeling approach was validated using an external testing set of data.

  4. A linear solvation energy relationship model of organic chemical partitioning to particulate organic carbon in soils and sediments.

    PubMed

    Kipka, Undine; Di Toro, Dominic M

    2011-09-01

    Predicting the association of contaminants with particulate organic matter in the environment is critical in determining the fate and bioavailability of chemicals. A ubiquitous measure of contaminant association with soil and sediment particulate organic matter is the organic carbon partition coefficient K(OC) . Chemical class-specific models relating the K(OC) to the octanol-water partition coefficient K(OW) have been used to predict the partitioning to organic carbon in the water column and sediment for nonpolar hydrophobic pollutants and some polar pollutants. A single linear solvation energy relationship (LSER) is proposed as a simpler and chemically based alternative for predicting K(OC) for a more diverse set of compounds. A chemically diverse set of K(OC) data is used to obtain a more robust and more universally representative model of organic carbon partitioning than previously available LSER models. The resulting model has a root mean square error (RMSE) of prediction for log K(OC) of RMSE = 0.48 for the fitted data set and RMSE = 0.55 for an independent data set. An analysis of LSER coefficients highlights the relative importance of hydrogen bonding interactions.

  5. 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 ...

  6. 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...

  7. [Application of Metabolomics to Multiple Chemical Sensitivity Research].

    PubMed

    Katoh, Takahiko; Fujiwara, Yuki; Nakashita, Chihiro; Lu, Xi; Hisada, Aya; Miyazaki, Wataru; Azuma, Kenichi; Tanigawa, Mari; Uchiyama, Iwao; Kunugita, Naoki

    2016-01-01

    Multiple chemical sensitivity (MCS) is an acquired chronic disorder characterized by nonspecific symptoms in multiple organ systems associated with exposure to low-level chemicals. Diagnosis of MCS can be difficult because of the inability to assess the causal relationship between exposure and symptoms. No standardized objective measures for the identification of MCS and no precise definition of this disorder have been established. Recent technological advances in mass spectrometry have significantly improved our capacity to obtain more data from each biological sample. Metabolomics comprises the methods and techniques that are used to determine the small-level molecules in biofluids and tissues. The metabolomic profile-the metabolome-has multiple applications in many biological sciences, including the development of new diagnostic tools for medicine. We performed metabolomics to detect the difference between 9 patients with MCS and 9 controls. We identified 183 substances whose levels were beyond the normal detection limit. The most prominent differences included significant increases in the levels of both hexanoic acid and pelargonic acid, and also a significant decrease in the level of acetylcarnitine in patients with MCS. In conclusion, using metabolomics analysis, we uncovered a hitherto unrecognized alteration in the levels of metabolites in MCS. These changes may have important biological implications and may have a significant potential for use as biomarkers.

  8. 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.

  9. 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

  10. 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. PMID:24979762

  11. 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.

  12. 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.

  13. Directory of Research Organizations in Education. Research, Development, Dissemination, Evaluation and Policy Studies.

    ERIC Educational Resources Information Center

    Lehming, Rolf, Ed.

    This directory lists the names, addresses, and telephone numbers of 2,418 organizations and organizational units in the United States that perform research activities related to education. The data were collected through the American Registry of Research and Research-Related Organizations in Education project (ARROE). If provided by an…

  14. 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…

  15. 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.

  16. 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. PMID:21637880

  17. Chemical Reactivity of alpha-Pinene-derived Products in the Aqueous Phase: Implications on the Fate of Organic Nitrates

    NASA Astrophysics Data System (ADS)

    Rindelaub, J. D.; Hostetler, M. A.; Lipton, M. A.; Shepson, P. B.

    2014-12-01

    The production of organic nitrates has significant atmospheric importance due to the impact on regional air quality by influencing NOx lifetimes and ozone formation. Additionally, these low volatility compounds readily partition into the particle phase and are important contributors to secondary organic aerosol. Once in the aerosol phase, organic nitrates undergo further chemical reactions that govern their fate in the atmosphere and, consequently, their impact on air quality. Recent research indicates that the presence of water on aerosol particles has a major impact on the reactivity of organic nitrates and that condensed phase hydrolysis leads to the destruction of organic nitrate species, depending on structure. Despite this knowledge, the chemical mechanisms, products, product reactivity and volatility are still uncertain, negatively impacting our understanding of aerosol phase processing and the contribution to air quality. To further understand the atmospheric impact of aerosol phase hydrolysis, we analyzed both condensed phase hydrolysis reactions involving alpha-pinene-derived standards and alpha-pinene photochemical chamber reaction filter samples, using a suite of spectroscopic and mass spectrometric techniques. We were able to measure the pH-dependent hydrolysis rate constants for several types of organic nitrates and identify specific reaction products. The chemistry involved exhibits a strong dependence on pH, providing important mechanistic clues. The results of this study will significantly contribute to our knowledge of aerosol phase chemistry and the impact on regional air quality with respect to the fate of organic nitrate species.

  18. A Sampler of Qualitative Research in Organized Camping.

    ERIC Educational Resources Information Center

    Chenery, Mary Faeth

    1987-01-01

    Suggests assumptions upon which qualitative research is based are appropriate for studying organized camping because of reality, causality, generalizability, and objectivity. Summarizes five studies using qualitative methods to demonstrate findings that may result from this approach. (NEC)

  19. The costs of safeguarding privacy: one research organization's experience.

    PubMed

    Slaughter, Pamela M; Leman, Kevin; McGill, Peggy; Varney, Carolynne

    2004-01-01

    While academic health research has always observed strict vigilance in the guardianship of the rich information found in health databases, new legislation faced by all organizations ups the ante even higher. Research organizations like the Institute for Clinical Evaluative Sciences are delving into even more rigorous policies to keep sensitive information secure while preserving the value that dedicated research provides. The costs of implementing privacy protections are of great concern to Canadian researchers. This report discusses basic costs associated with privacy practices undertaken at the Institute.

  20. 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.

  1. 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...

  2. 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…

  3. 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...

  4. 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.

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

    PubMed

    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.

  6. 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

  7. How useful are olfactometer experiments in chemical ecology research?

    PubMed Central

    Ballhorn, Daniel J.; Kautz, Stefanie

    2013-01-01

    Olfactometer experiments, in which arthropods are given the choice between two or more odor sources to test behavioral preferences, are commonly used in chemical ecology research. Results of such often lead to conclusions on behavior in an ecologically relevant setting. However, it is widely unknown how well these experiments reflect actual behavior in nature. Recently, we used natural insect herbivores of wild lima bean plants to evaluate their behavior in Y-tube olfactometer experiments compared with feeding experiments. We demonstrated that depending on volatile concentration, insect sex significantly determined preference, and that independent of sex, the actual feeding choice of insects depended on defensive short-distance cues, which did not correlate with volatile cues emitted by the plants. Thus, our study shows that olfactory decisions do not reflect actual feeding choice and that olfactometer experiments may only provide a limited and simplified picture of actual decision making by insects. PMID:23986812

  8. Electrical and chemical sensors for biological cell research

    NASA Astrophysics Data System (ADS)

    Edell, D. J.; McNeil, V. M.; Curley, M. G.; Wolfe, J. H.

    Electrical and chemical microsensors for biological cell research allow for the continuous study of biological systems under normal physiological conditions. Two sensor technologies which take most advantage of microfabrication technology are discussed. One is being developed for monitoring the environment of cancer cells during radiotherapy, chemotherapy, and hyperthermia treatment. Of current interest is the measurement of temperature and interstitial free oxygen concentration distributions in cancer tissues prior to and during various treatments. The second technology discussed is being developed for monitoring the extracellular ionic currents from electrogenic cells in culture. The ability to build integrated circuits over large areas of a silicon wafer which can impedance transform the signals and multiplex a large array of contacts is being used.

  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. PMID:21782749

  10. 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

  11. 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

  12. Investigation into the chemical, thermal and radiological changes of organic chemicals added to the underground storage tanks at Hanford

    SciTech Connect

    Samuels, W.D.; Camaioni, D.M.; Clauss, S.A.; Linehan, J.C.

    1996-10-01

    Uranium and plutonium production at the Hanford site produced large quantities of radioactive by-products and contaminated process chemicals that are presently stored in underground tanks awaiting treatment and disposal. Having been made strongly alkaline and then subjected to successive water evaporation campaigns to increase storage capacity, the wastes now exist in the physical forms of salt cakes, metal oxide sludges, and saturated aqueous brine solutions. Those waste storage tanks containing organic process chemicals mixed with nitrate/nitrite salt wastes are thought to be at risk for fuel-nitrate combustion accidents. To support resolution of this potential hazard, we are studying how organic chemicals added to the tanks may have {open_quotes}aged{close_quotes} or changed under storage conditions. Simulated wastes have been irradiated with gamma rays at temperatures between ambient and 90{degrees}C and subsequently analyzed quantitatively. The presentation will report findings on the rates and products of organic degradation. Reaction mechanisms and implications of the findings will be discussed.

  13. 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.

  14. Separation of chemical reaction intermediates by metal-organic frameworks.

    PubMed

    Centrone, Andrea; Santiso, Erik E; Hatton, T Alan

    2011-08-22

    HPLC columns custom-packed with metal-organic framework (MOF) materials are used for the separation of four small intermediates and byproducts found in the commercial synthesis of an important active pharmaceutical ingredient in methanol. In particular, two closely related amines can be separated in the methanol reaction medium using MOFs, but not with traditional C18 columns using an optimized aqueous mobile phase. Infrared spectroscopy, UV-vis spectroscopy, X-ray diffraction, and thermogravimetric analysis are used in combination with molecular dynamic simulations to study the separation mechanism for the best-performing MOF materials. It is found that separation with ZIF-8 is the result of an interplay between the thermodynamic driving force for solute adsorption within the framework pores and the kinetics of solute diffusion into the material pores, while the separation with Basolite F300 is achieved because of the specific interactions between the solutes and Fe(3+) sites. This work, and the exceptional ability to tailor the porous properties of MOF materials, points to prospects for using MOF materials for the continuous separation and synthesis of pharmaceutical compounds.

  15. 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.

  16. Benchmarking biology research organizations using a new, dedicated tool.

    PubMed

    van Harten, Willem H; van Bokhorst, Leonard; van Luenen, Henri G A M

    2010-02-01

    International competition forces fundamental research organizations to assess their relative performance. We present a benchmark tool for scientific research organizations where, contrary to existing models, the group leader is placed in a central position within the organization. We used it in a pilot benchmark study involving six research institutions. Our study shows that data collection and data comparison based on this new tool can be achieved. It proved possible to compare relative performance and organizational characteristics and to generate suggestions for improvement for most participants. However, strict definitions of the parameters used for the benchmark and a thorough insight into the organization of each of the benchmark partners is required to produce comparable data and draw firm conclusions.

  17. 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

    2016-01-01

    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. PMID:26619247

  18. 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

  19. 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

  20. Occurrence of organic chemicals in two rivers inhabited by Ozark hellbenders (Cryptobranchus alleganiensis bishopi).

    PubMed

    Solís, M E; Liu, C C; Nam, P; Niyogi, D K; Bandeff, J M; Huang, Y-W

    2007-10-01

    Ozark Hellbender (Cryptobranchus alleganiensis bishopi) populations are in decrease throughout their native range with rare recruitment of young. Increased estrogenic chemical levels and alterations of physicochemical properties in their habitat may play a significant role in this phenomenon. We report here the first systematic, comprehensive study of organic chemical concentrations and physical and nutrient parameters in two rivers containing Ozark hellbender populations. Water samples were collected monthly from August 2003 to November 2004. Concentrations of 21 organic chemicals were determined using gas chromatography-mass spectrometry. Nine organic chemicals were detected. Benzyl butyl phthalate, dibutyl phthalate, bisphenol A, and beta-sitosterol were all detected >85% of the time, with median concentrations of 18 to 234 ng/L and maximum concentrations of 198 to 4141 ng/L. Individually, concentrations of nutrients and organic chemicals were much lower than those shown previously in laboratory and field experiments to have reproductive effects on amphibians. Nevertheless, hellbenders are exposed to a variety of chemicals with potential estrogenic effects. Our study establishes the basis to examine the specific effects of the detected concentrations, alone and in combination, on the Ozark hellbenders. PMID:17728992

  1. 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.

  2. 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.

  3. [Research progress of phytoestrogens-like chemical constituents in natural medicines].

    PubMed

    Yuan, Ting-Ting; Zhang, Nai-Dan; He, Yong-Jing; Li, Mei; Xu, Hong-Tao; Zhang, Qiao-Yan

    2014-12-01

    Phytoestrogens, which can bind with estrogen receptor and produce estrogen-like effects, are a kind of nonsteroidal compound in plant. Phytoestrogens chemically include isoflavones, coumarins, lignans and other compounds. Phytoestrogens are selective estrogen receptor modulator, and have therapeutical effects on breast cancer, prostate cancer, cardiovascular disease, menopausal symptoms, osteoporosis and other disease, however, do not produce stimulatory hyperplasia effects on uterus, mammary glands and other tissues and organs with positive estrogen receptor. Long-term exposure or excessive use of phytoestrogens maybe affects male reproductive system and hematopoietic function of fetus. Some questions need to be further studied, such as evaluation criteria on biological activity, adverse effects, and action mechanism of phytoestrogen. This review covers plant sources, chemical structure, pharmacological activity and safety of phytoestrogens. It will provide a useful reference for intensive research and rational utilization the phytoestrogens. PMID:25911795

  4. [Research progress of phytoestrogens-like chemical constituents in natural medicines].

    PubMed

    Yuan, Ting-Ting; Zhang, Nai-Dan; He, Yong-Jing; Li, Mei; Xu, Hong-Tao; Zhang, Qiao-Yan

    2014-12-01

    Phytoestrogens, which can bind with estrogen receptor and produce estrogen-like effects, are a kind of nonsteroidal compound in plant. Phytoestrogens chemically include isoflavones, coumarins, lignans and other compounds. Phytoestrogens are selective estrogen receptor modulator, and have therapeutical effects on breast cancer, prostate cancer, cardiovascular disease, menopausal symptoms, osteoporosis and other disease, however, do not produce stimulatory hyperplasia effects on uterus, mammary glands and other tissues and organs with positive estrogen receptor. Long-term exposure or excessive use of phytoestrogens maybe affects male reproductive system and hematopoietic function of fetus. Some questions need to be further studied, such as evaluation criteria on biological activity, adverse effects, and action mechanism of phytoestrogen. This review covers plant sources, chemical structure, pharmacological activity and safety of phytoestrogens. It will provide a useful reference for intensive research and rational utilization the phytoestrogens.

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

    PubMed

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

    2013-09-01

    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.

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

    PubMed

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

    2013-09-01

    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. PMID:23924323

  7. 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…

  8. 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

  9. 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

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

    PubMed

    Raya, Rampalli Prabhakara; Panneerselvam, Sivapragasam

    2013-09-01

    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

  11. 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

  12. Characterization of the reactivities of volatile organic compounds using a master chemical mechanism.

    PubMed

    Derwent, R G; Jenkin, M E; Saunders, S M; Pilling, M J

    2001-05-01

    A comprehensive description of the ozone-forming potentials of 101 organic compounds has been constructed under North American urban "averaged conditions" using a detailed master chemical mechanism and a simple air parcel trajectory model. This chemical mechanism describes the reactions of 3603 chemical species taking part in more than 10,500 chemical reactions. An index value has been calculated for each organic compound, which describes the increment in ozone concentrations found downwind of an urban area following the emission of a fixed increment in the mass emission of each organic compound. These indices, termed photochemical ozone creation potentials (POCPs), have been expressed on a scale relative to ethylene (ethene) = 100, and, a reactivity scale has been generated for alkanes, alkenes, and oxygenated and halogenated organic compounds. A high degree of correlation (R2 = 0.9) was found between these POCP values and the most widely accepted urban reactivity scale. While the reactivities of most of the 86 organic compounds compared fell within a consistent range, significant discrepancies were found for only 5 compounds. Single-day or multiday conditions appear to be important in establishing quantitative reactivity scales for the less reactive organic compounds.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 15 CFR Supplement No. 2 to Part 715 - Examples of Unscheduled Discrete Organic Chemicals (UDOCs) and UDOC Production

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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...

  1. Polar organic chemical integrative sampler (POCIS): application for monitoring organic micropollutants in wastewater effluent and surface water.

    PubMed

    Miège, Cécile; Budzinski, Hélène; Jacquet, Romain; Soulier, Coralie; Pelte, Thomas; Coquery, Marina

    2012-02-01

    In this paper, we discuss the advantages and drawbacks of POCIS (Polar Organic Chemical Integrative Sampler) for the evaluation of river water quality downstream of wastewater treatment plants. POCIS proved well adapted to sampling alkylphenols and several pharmaceuticals. Concentration factors and the decrease in limits of quantification, compared to grab water sample analyses, were significant except for hormones, β-blockers and bronchodilators. Promising preliminary results obtained in situ on deuterated atenolol used as a performance reference compound need to be confirmed in-lab. This work confirms that POCIS is a valuable tool for monitoring hydrophilic organic molecules in river and wastewaters. PMID:22193508

  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. 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

  4. 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. PMID:26192805

  5. 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.

  6. Self-Organized Traveling Chemo-Hydrodynamic Fingers Triggered by a Chemical Oscillator.

    PubMed

    Escala, D M; Budroni, M A; Carballido-Landeira, J; De Wit, A; Muñuzuri, A P

    2014-02-01

    Pulsatile chemo-hydrodynamic patterns due to a coupling between an oscillating chemical reaction and buoyancy-driven hydrodynamic flows can develop when two solutions of separate reactants of the Belousov-Zhabotinsky reaction are put in contact in the gravity field and conditions for chemical oscillations are met in the contact zone. In regular oscillatory conditions, localized periodic changes in the concentration of intermediate species induce pulsatile density gradients, which, in turn, generate traveling convective fingers breaking the transverse symmetry. These patterns are the self-organized result of a genuine coupling between chemical and hydrodynamic modes.

  7. 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.

  8. Toxicity of organic chemicals and their mixtures to activated sludge microorganisms

    SciTech Connect

    Hall, E.; Sun, B.; Prakash, J.; Nirmalakhandan, N.

    1996-05-01

    Toxicity of eight- and 10-component mixtures of several organic chemicals to activated sludge (A/S) microorganisms was analyzed. The joint toxic effects of the tested chemicals were found to be simply additive. The quantitative structure-activity relationship (QSAR) technique using molecular connectivity indices was used to develop single variable models to fit single chemical toxicity data. A QSAR-based approach is proposed to predict the concentrations of components in equitoxic mixtures that would jointly cause 50% inhibition of the A/S microorganisms. The validity of this predictive approach was demonstrated by comparing the predicted concentrations against those found experimentally.

  9. Self-Organized Traveling Chemo-Hydrodynamic Fingers Triggered by a Chemical Oscillator.

    PubMed

    Escala, D M; Budroni, M A; Carballido-Landeira, J; De Wit, A; Muñuzuri, A P

    2014-02-01

    Pulsatile chemo-hydrodynamic patterns due to a coupling between an oscillating chemical reaction and buoyancy-driven hydrodynamic flows can develop when two solutions of separate reactants of the Belousov-Zhabotinsky reaction are put in contact in the gravity field and conditions for chemical oscillations are met in the contact zone. In regular oscillatory conditions, localized periodic changes in the concentration of intermediate species induce pulsatile density gradients, which, in turn, generate traveling convective fingers breaking the transverse symmetry. These patterns are the self-organized result of a genuine coupling between chemical and hydrodynamic modes. PMID:26276584

  10. Control of neuronal network organization by chemical surface functionalization of multi-walled carbon nanotube arrays

    PubMed Central

    Liu, Jie; Appaix, Florence; Bibari, Olivier; Marchand, Gilles; Benabid, Alim-Louis; Sauter-Starace, Fabien; Waard, Michel De

    2011-01-01

    Carbon nanotube substrates are promising candidates for biological applications and devices. Interfacing of these carbon nanotubes with neurons can be controlled by chemical modifications. In this study, we investigated how chemical surface functionalisation of multi-walled carbon nanotube arrays (MWNT-A) influences neuronal adhesion and network organization. Functionalisation of MWNT-A dramatically modifies length of neurite fascicles, cluster interconnection success rate, and percentage of neurites that escape from the clusters. We propose that chemical functionalisation represents a method of choice for developing applications in which neuronal patterning on MWNT-A substrates is a must. PMID:21436508

  11. 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.

  12. 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

  13. 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.

  14. 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...

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. AICD: Advanced Industrial Concepts Division Biological and Chemical Technologies Research Program

    NASA Astrophysics Data System (ADS)

    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, and a listing of program output including a bibliography of published work, patents, and awards arising from work supported by BCTR.

  20. 78 FR 40746 - Urban Indian Education and Research Organization Cooperative Agreement Program; Office of Urban...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ... HUMAN SERVICES Indian Health Service Urban Indian Education and Research Organization Cooperative... applications for the Urban Indian Education and Research Organization Cooperative Agreement Program project... Indian organization to act as an education and research partner for OUIHP and urban Indian...

  1. Relationships between exposure and dose in aquatic toxicity tests for organic chemicals.

    PubMed

    Mackay, Donald; McCarty, Lynn S; Arnot, Jon A

    2014-09-01

    There is continuing debate about the merits of exposure-based toxicity metrics such as median lethal concentration (LC50) versus organism-based metrics such as critical body residue (CBR) as indicators of chemical toxicity to aquatic organisms. To demonstrate relationships and differences between these 2 metrics, the authors applied a simple one-compartment toxicokinetic mass-balance model for water-exposed fish for a series of hypothetical organic chemicals exhibiting baseline narcotic toxicity. The authors also considered the influence of several toxicity-modifying factors. The results showed that the results of standard toxicity tests, such as the LC50, are strongly influenced by several modifying factors, including chemical and organism characteristics such as hydrophobicity, body size, lipid content, metabolic biotransformation, and exposure durations. Consequently, reported LC50s may not represent consistent dose surrogates and may be inappropriate for comparing the relative toxicity of chemicals. For comparisons of toxicity between chemicals, it is preferable to employ a delivered dose metric, such as the CBR. Reproducible toxicity data for a specific combination of chemical, exposure conditions, and organism can be obtained only if the extent of approach to steady state is known. Suggestions are made for revisions in test protocols, including the use of models in advance of empirical testing, to improve the efficiency and effectiveness of tests and reduce the confounding influences of toxicity-modifying factors, especially exposure duration and metabolic biotransformation. This will assist in linking empirical measurements of LC50s and CBRs, 2 different but related indicators of aquatic toxicity, and thereby improve understanding of the large existing database of aquatic toxicity test results.

  2. 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

  3. 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:…

  4. 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

  5. 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.

  6. 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.

  7. 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…

  8. University-Based Research Centers: Characteristics, Organization, and Administrative Implications

    ERIC Educational Resources Information Center

    Sa, Creso M.

    2008-01-01

    This paper examines the characteristics and organizational issues associated with university-based research centers. The first section sketches general characteristics and functions of centers. The second section examines major issues concerning the organization of centers, including funding and sustainability, center autonomy, and relations with…

  9. Attendance Factors for a Regional Research Organization's Annual Meeting.

    ERIC Educational Resources Information Center

    Boser, Judith A.; And Others

    One of the indicators of the health of an organization is the number of individuals participating in its annual meeting. Factors influencing meeting attendance and the relationships between positive attendance indicators and registration were studied for the Mid-South Educational Research Association, using participant data for 1984 through 1992.…

  10. 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.

  11. Topological insulator Bi2Te3 films synthesized by metal organic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Cao, Helin; Venkatasubramanian, Rama; Liu, Chang; Pierce, Jonathan; Yang, Haoran; Zahid Hasan, M.; Wu, Yue; Chen, Yong P.

    2012-10-01

    Topological insulator (TI) materials such as Bi2Te3 and Bi2Se3 have attracted strong recent interests. Large scale, high quality TI thin films are important for developing TI-based device applications. In this work, structural and electronic properties of Bi2Te3 thin films deposited by metal organic chemical vapor deposition (MOCVD) on GaAs (001) substrates were characterized via x-ray diffraction (XRD), Raman spectroscopy, angle-resolved photoemission spectroscopy (ARPES), and electronic transport measurements. The characteristic topological surface states with a single Dirac cone have been clearly revealed in the electronic band structure measured by ARPES, confirming the TI nature of the MOCVD Bi2Te3 films. Resistivity and Hall effect measurements have demonstrated relatively high bulk carrier mobility of ˜350 cm2/Vs at 300 K and ˜7400 cm2/Vs at 15 K. We have also measured the Seebeck coefficient of the films. Our demonstration of high quality topological insulator films grown by a simple and scalable method is of interests for both fundamental research and practical applications of thermoelectric and TI materials.

  12. 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.

  13. 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.

  14. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Organic chemicals, sampling...

  15. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Organic chemicals, sampling...

  16. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Organic chemicals, sampling...

  17. 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...

  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. 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…

  20. Increasing Minority Research Participation Through Community Organization Outreach

    PubMed Central

    Alvarez, Roger A.; Vasquez, Elias; Mayorga, Carla C.; Feaster, Daniel J.; Mitrani, Victoria B.

    2008-01-01

    Recruitment is one of the most significant challenges in conducting research with ethnic minority populations. Establishing relationships with organizations that serve ethnic minority communities can facilitate recruitment. To create a successful recruitment process, a strategic plan of action is necessary prior to implementing community outreach efforts. For this study population of women who were HIV+ and recovering from substance abuse disorder, the authors found that establishing trust with community organizations that serve these women allows for a productive referral relationship. Although the majority of women in this study are African American, the authors were particularly challenged in recruiting Hispanic women. This article presents a recruitment process model that has facilitated our recruitment efforts and has helped the authors to organize, document, and evaluate their community outreach strategies. This model can be adopted and adapted by nurses and other health researchers to enhance engagement of minority populations. PMID:16829637

  1. 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.

  2. Direct conversion of radioactive and chemical waste containing metals, ceramics, amorphous solids, and organics to glass

    SciTech Connect

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1994-05-02

    The Glass Material Oxidation and Dissolution System (CMODS) is a new process for direct conversion of radioactive, mixed, and chemical wastes to glass. The wastes can be in the chemical forms of metals, ceramics, amorphous solids, and organics. GMODS destroys organics and it incorporates heavy metals and radionuclides into a glass. Processable wastes may include miscellaneous spent fuels (SF), SF hulls and hardware, plutonium wastes in different forms, high-efficiency particulate air (HEPA) filters, ion-exchange resins, failed equipment, and laboratory wastes. Thermodynamic calculations indicate theoretical feasibility. Small-scale laboratory experiments (< 100 g per test) have demonstrated chemical laboratory feasibility for several metals. Additional work is needed to demonstrate engineering feasibility.

  3. 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. PMID:26360870

  4. A chemical adsorption system for the sampling of gaseous organic pollutants in operating theatre atmospheres.

    PubMed

    Halliday, M M; Carter, K B

    1978-10-01

    The development of an air sampler and its use in measuring organic pollutants in operating theatre atmospheres are described. Air was sampled continuously during an operating session and the results obtained represent the average pollution at the sample site during that session. The technique involved the chemical adsorption of organic vapours to polymer beads and pollutants thus trapped could be stored for several days before thermal desorption and analysis by gas chromatography. The three most abundant organic pollutants were ethanol, propan-2-ol (isopropanol) and halothane.

  5. 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.

  6. 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.

  7. The chemical evolution & physical properties of organic aerosol: A molecular structure based approach

    NASA Astrophysics Data System (ADS)

    Wei, Yiyi; Cao, Tingting; Thompson, Jonathan E.

    2012-12-01

    Global climate, atmospheric chemistry, and air quality are affected by tropospheric particulate matter. Recent measurements suggest organic compounds present in this haze comprise roughly half of total aerosol fine mass concentration globally. Unlike the well-constrained processes which result in formation of nitrate or sulfate aerosol, the oxidation of volatile organics in the atmosphere can lead to thousands of stable compounds in the aerosol phase. Development of a tractable framework to consider the chemical and physical evolution of the organic aerosol is crucial for modeling its effect on global climate. Here we show coupling a 3-dimensional coordinate system defined by the molecular descriptors of molecular weight, heteroatom mass, and double bond equivalents (D.B.E.) with high-resolution molecular mass spectrometry is a powerful approach for describing key properties of the organic aerosol. The scheme is conceptually simple, yet maintains sufficient complexity to be compatible with quantitative structure-property relationships (QSPRs) used to predict chemical and physical properties that govern aerosol behavior. From available data, both ambient organic aerosol and laboratory generated organic aerosol frequently occupy the region characterized by <10 D.B.E. <600 M.W. and <200 heteroatom mass. A QSPR analysis conducted illustrates spatial trends within the 3D space for volatility and Henry's law constants for 31,000 organic compounds considered.

  8. The solubility of hydrophobic aromatic chemicals in organic solvent/water mixtures

    SciTech Connect

    Dickhut, R.M.

    1989-01-01

    The influence of dissolved organic solvents on the aqueous phase solubility of hydrophobic aromatic chemicals was investigated. To provide a basis for a comprehensive evaluation of the importance of cosolvent properties on solubility, the effects of several different organic cosolvents on the solubility of a model hydrophobic solute, naphthalene, were determined. Naphthalene solubility was measured in binary, ternary, and quaternary alcohol/water (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol) mixtures, binary ketone/water (acetone, methylethylketone, diethylketone), and aromatic organic solvent/water (benzene, toluene) mixtures. The solubility data were statistically evaluated and used to obtain an estimate of the overall accuracy of solubility measurements of hydrophobic chemicals in organic solvent/water mixtures. An accurate data base for mixed solvent solubility was established by combining the solubility data with additional solubility data obtained experimentally and from the literature. Thermodynamic models for predicting solubility in organic solvent/water mixtures were tested against the experimental data. The effects of organic cosolvent properties and solute hydrophobicity on solubility behavior and model predictive capability were evaluated. The results were used to evaluate the accuracy of existing models for predicting solubility and to explore possible molecular interactions in organic solvent/water mixtures.

  9. 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.

  10. A mathematical model for the transport and fate of organic chemicals in unsaturated/saturated soils.

    PubMed Central

    Lindstrom, F T; Piver, W T

    1985-01-01

    A mathematical model, simulating the transport and fate of nonionizable organic compounds in unsaturated/saturated porous media (soils) in a terrestrial microcosm has been developed. Using the principles of water mass, momentum, heat energy and chemical mass balance, the three fields: moisture, temperature, and liquid phase chemical concentration are solved for simultaneously by coupling the soil slab to an environmentally realistic air-soil interface (a dynamic free boundary) conditions and a prescribed height water table. The environmental conditions at the soil surface-air chamber interface are easily changed, via geometric scaling factors, to simulate either an open agricultural field or a landfill type of situation. Illustrative simulation runs examine the effects of different soil-chemical characteristics on hydrological and chemical concentration profiles. PMID:4029096

  11. 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...

  12. 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

  13. 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.

  14. 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

  15. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests.

    PubMed

    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

  16. [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.

  17. 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.

  18. 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.

  19. 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)

  20. 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...

  1. 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

  2. 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.

  3. 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. PMID:24088153

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:26104164

  8. 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.

  9. 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. PMID:25461748

  10. 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.

  11. 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.

  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. PMID:25884713

  13. Differences in Chemical Composition of Soil Organic Carbon Resulting From Long-Term Fertilization Strategies

    PubMed Central

    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. PMID:25884713

  14. 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.

  15. Molecular corridors represent the multiphase chemical evolution of secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Shiraiwa, M.; Berkemeier, T.; Schilling-Fahnestock, K. A.; Seinfeld, J. H.; Pöschl, U.

    2014-03-01

    The dominant component of atmospheric organic aerosol is that derived from the oxidation of volatile organic compounds (VOCs), so-called secondary organic aerosol (SOA). SOA consists of a multitude of organic compounds, only a small fraction of which has historically been identified. Formation and evolution of SOA is a complex process involving coupled chemical reaction and mass transport in the gas and particle phases. Current SOA models do not embody the full spectrum of reaction and transport processes nor do they identify the dominant rate-limiting steps in SOA formation. The recent advent of soft ionization mass spectrometry methods now facilitates a more complete molecular identification of SOA than heretofore possible. Based on such novel measurements, we show here that the chemical evolution of SOA from a variety of VOC precursors adheres to characteristic "molecular corridors" with a tight inverse correlation between volatility and molar mass. Sequential and parallel reaction oxidation and dimerization pathways progress along these corridors through characteristic regimes of reaction-, diffusion-, or accommodation-limited multiphase chemical kinetics that can be classified according to reaction location, degree of saturation, and extent of heterogeneity of gas and particle phases. These molecular corridors constrain the properties of unidentified products and reaction pathways and rates of SOA evolution, thereby facilitating the further development of aerosol models for air quality and climate.

  16. 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.

  17. Aging of Secondary Organic Aerosol from β-Pinene: Changes in Chemical Composition, Density and Morphology

    NASA Astrophysics Data System (ADS)

    Sarrafzadeh, M.; Hastie, D. R.

    2013-12-01

    Biogenic volatile organic compounds (VOC) are emitted in large quantities into the atmosphere. These VOC, which includes β-pinene, can react to produce secondary organic aerosols (SOA), which contribute to a substantial fraction of ambient organic aerosols and are known to adversely affect visibility, climate and health. Despite this, the current knowledge regarding the SOA composition, their physical properties and the chemical aging processes they undergo in the atmosphere is limited. In this study, chemical aging of SOA generated from the photooxidation of β-pinene was investigated in the York University smog chamber. The formation and aging of both gas and particle phase products were analyzed using an atmospheric pressure chemical ionization triple quadrupole mass spectrometer. The density of secondary organic matter was also simultaneously measured over the course of the aging experiments, allowing us to improve our understanding in changes in particle composition that may occur. In addition, particle phase and shape was investigated for generated particles from β-pinene oxidation by scanning electron microscope (SEM). Results of this work, including particle density and morphology will be presented as well as comparisons of gas and particle phase products time profiles during aging.

  18. K-39 quadrupolar and chemical shift tensors for organic potassium complexes and diatomic molecules.

    PubMed

    Lee, Philip K; Chapman, Rebecca P; Zhang, Lei; Hu, Jiaxin; Barbour, Leonard J; Elliott, Elizabeth K; Gokel, George W; Bryce, David L

    2007-12-20

    Solid-state potassium-39 NMR spectra of two potassium complexes of crown-ether-based organic ligands (1.KI and 2) have been acquired at 11.75 and 21.1 T and interpreted to provide information on the 39K quadrupolar and chemical shift tensors. The analyses reveal a large potassium chemical shift tensor span of 75+/-20 ppm for 1.KI. This appears to be the first such measurement for potassium in an organic complex, thereby suggesting the utility of potassium chemical shift tensors for characterizing organic and biomolecular K+ binding environments. Compound 2 exhibits a cation-pi interaction between K+ and a phenyl group, and therefore, the 39K NMR tensors obtained for this compound must be partly representative of this interaction. Analyses of potassium-39 spin-rotation data for gaseous 39K19F and 39K35Cl available from molecular beam experiments performed by Cederberg and co-workers reveal the largest potassium CS tensor spans known to date, 84.39 and 141 ppm, respectively. Collectively, the results obtained highlight the potential of ultrahigh-field potassium-39 solid-state NMR spectroscopy and, in particular, the wide range of the anisotropy of the potassium CS tensor when organic and diatomic systems are considered.

  19. 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.

  20. 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…

  1. 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. PMID:27316676

  2. 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.

  3. Using conditional inference trees and random forests to predict the bioaccumulation potential of organic chemicals.

    PubMed

    Strempel, Sebastian; Nendza, Monika; Scheringer, Martin; Hungerbühler, Konrad

    2013-04-01

    The present study presents a data-oriented, tiered approach to assessing the bioaccumulation potential of chemicals according to the European chemicals regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). The authors compiled data for eight physicochemical descriptors (partition coefficients, degradation half-lives, polarity, and so forth) for a set of 713 organic chemicals for which experimental values of the bioconcentration factor (BCF) are available. The authors employed supervised machine learning methods (conditional inference trees and random forests) to derive relationships between the physicochemical descriptors and the BCF values. In a first tier, the authors established rules for classifying a chemical as bioaccumulative (B) or nonbioaccumulative (non-B). In a second tier, the authors developed a new tool for estimating numerical BCF values. For both cases the optimal set of relevant descriptors was determined; these are biotransformation half-life and octanol-water distribution coefficient (log D) for the classification rules and log D, biotransformation half-life, and topological polar surface area for the BCF estimation tool. The uncertainty of the BCF estimates obtained with the new estimation tool was quantified by comparing the estimated and experimental BCF values of the 713 chemicals. Comparison with existing BCF estimation methods indicates that the performance of this new BCF estimation tool is at least as high as that of existing methods. The authors recommend the present study's classification rules and BCF estimation tool for a consensus application in combination with existing BCF estimation methods.

  4. Flip-chip packaged CMOS chemical microsystem for detection of volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Koll, Andreas; Kawahito, Shoji; Mayer, Felix; Hagleitner, Christoph; Scheiwiller, D.; Brand, Oliver; Baltes, Henry

    1998-07-01

    We present a packaged single-chip microsystem for the detection of organic vapors. The sensor is fabricated using a 0.8 micrometers CMOS IC process provided by AMS Austria Mikro Systeme. Volatile organic compounds are detected by measuring the capacitance change of three polymer coated interdigitated capacitors due to analyte absorption. To protect the read-out circuitry from the organic vapors, the device is packaged using flip-chip technology. This technology allows for openings in the ceramic substrate for the sensing capacitors while hermetically sealing the remaining chip area. Measurements for different volatile organic compounds and chemically sensitive polymer layers are presented. The packaged microsensor array is a first step towards the realization of a small, low cost electronic nose on a single chip.

  5. 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.

  6. 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

  7. The role of organic matter in the removal of emerging trace organic chemicals during managed aquifer recharge.

    PubMed

    Rauch-Williams, T; Hoppe-Jones, C; Drewes, J E

    2010-01-01

    This study explored the effect of different bulk organic carbon matrices on the fate of trace organic chemicals (TOrC) during managed aquifer recharge (MAR). Infiltration through porous media was simulated in biologically active column experiments under aerobic and anoxic recharge conditions. Wastewater effluent derived organic carbon types, differing in hydrophobicity and biodegradability (i. e., hydrophobic acids, hydrophilic carbon, organic colloids), were used as feed substrates in the column experiments. These carbon substrates while fed at the same concentration differed in their ability to support soil biomass growth during porous media infiltration. Removal of degradable TOrC (with the exception of diclofenac and propyphenazone) was equal or better under aerobic versus anoxic porous media infiltration conditions. During the initial phase of infiltration, the presence of biodegradable organic carbon (BDOC) enhanced the decay of degradable TOrC by promoting soil biomass growth, suggesting that BDOC served as a co-substrate in a co-metabolic transformation of these contaminants. However, unexpected high removal efficiencies were observed for all degradable TOrC in the presence of low BDOC concentrations under well adopted oligotrophic conditions. It is hypothesized that removal under these conditions is caused by a specialized microbial community growing on refractory carbon substrates such as hydrophobic acids. Findings of this study reveal that the concentration and character of bulk organic carbon present in effluents affect the degradation efficiency for TOrC during recharge operation. Specifically aerobic, oligotrophic microbiological soil environments present favorable conditions for the transformation of TOrC, including rather recalcitrant compounds such as chlorinated flame retardants.

  8. Combined physical, chemical and biological treatments of wastewater containing organics from a semiconductor plant.

    PubMed

    Lin, Sheng H; Kiang, Chang D

    2003-02-28

    Wastewater containing organics from a semiconductor plant was experimentally investigated in this study. The wastewater is characterized by strong color, high chemical oxygen demand (COD), a large amount of refractory volatile organic compounds and low biodegradability. Because of these characteristics, treatment of this wastewater by traditional activated sludge method is essentially impossible. In the present work, combined physical, chemical and biological methods were synergistically utilized to tackle the wastewater. The combined treatment consisted of air stripping, modified Fenton oxidation and sequencing batch reactor (SBR) method. Air stripping was employed to remove the majority of volatile organic components (notably isopropyl alcohol) from the wastewater, while the Fenton treatment decomposed the remaining refractory organics leading to simultaneous reductions of wastewater COD and color. After proper dilution with other low-strength, organics-containing wastewater stream, the wastewater effluent was finally treated by the SBR method. Experimental tests were conducted to determine the effectiveness and the optimum operating conditions of each treatment process. Test results clearly demonstrated the advantages of the combined treatments. The treatment train was found capable of lowering the wastewater COD concentration from as high as 80,000 mg/l to below 100mg/l and completely eliminating the wastewater color. The overall water quality of the final effluent exceeded the direct discharge standard and the effluent can even be considered for reuse.

  9. Chemical sinks of organic aerosol: kinetics and products of the heterogeneous oxidation of erythritol and levoglucosan.

    PubMed

    Kessler, Sean H; Smith, Jared D; Che, Dung L; Worsnop, Douglas R; Wilson, Kevin R; Kroll, Jesse H

    2010-09-15

    The heterogeneous oxidation of pure erythritol (C(4)H(10)O(4)) and levoglucosan (C(6)H(10)O(5)) particles was studied in order to evaluate the effects of atmospheric aging on the mass and chemical composition of atmospheric organic aerosol. In contrast to what is generally observed for the heterogeneous oxidation of reduced organics, substantial volatilization is observed in both systems. However, the ratio of the decrease in particle mass to the decrease in the concentration of the parent species is about three times higher for erythritol than for levoglucosan, indicating that details of chemical structure (such as carbon number, cyclic moieties, and oxygen-containing functional groups) play a governing role in the importance of volatilization reactions. The kinetics of the reaction indicate that while both compounds react at approximately the same rate, reactions of their oxidation products appear to be slowed substantially. Estimates of volatilities of organic species based on elemental composition measurements suggest that the heterogeneous oxidation of oxygenated organics may be an important loss mechanism of organic aerosol.

  10. Behavioral and Chemical Ecology of Marine Organisms with Respect to Tetrodotoxin

    PubMed Central

    Williams, Becky L.

    2010-01-01

    The behavioral and chemical ecology of marine organisms that possess tetrodotoxin (TTX) has not been comprehensively reviewed in one work to date. The evidence for TTX as an antipredator defense, as venom, as a sex pheromone, and as an attractant for TTX-sequestering organisms is discussed. Little is known about the adaptive value of TTX in microbial producers; thus, I focus on what is known about metazoans that are purported to accumulate TTX through diet or symbioses. Much of what has been proposed is inferred based on the anatomical distribution of TTX. Direct empirical tests of these hypotheses are absent in most cases. PMID:20411104

  11. Recent progress in artificial organ research at Tohoku University.

    PubMed

    Yambe, Tomoyuki; Yoshizawa, Makoto; Tanaka, Akira; Abe, Ken-ichi; Kawano, Satoyuki; Matsuki, Hidetoshi; Maruyama, Shigenao; Amae, Shintato; Wada, Naoshi; Kamiyama, Takamichi; Takagi, Toshiyuki; Luo, Run; Hayashi, Junko; Kovalev, Yuri A; X D Sha, Dan; Nanka, Shunsuke; Saijo, Yoshifumi; Mibiki, Yoshiyuki; Shibata, Mune-ichi; Nitta, Shin-ichi

    2003-01-01

    Tohoku University has developed various artificial organs over the last 30 years. Pneumatic driven ventricular assist devices with a silicone ball valve have been designed by the flow visualization method, and clinical trials have been performed in Tohoku University Hospital. On the basis of these developments, a pneumatic driven total artificial heart has been developed and an animal experimental evaluation was conducted. The development of artificial organs in Tohoku University has now progressed to the totally implantable type using the transcutaneous energy transmission system with amorphous fibers for magnetic shielding. Examples of implantable systems include a vibrating flow pump for ventricular assist device, an artificial myocardium by the use of shape memory alloy with Peltier elements, and an artificial sphincter for patients with a stoma. An automatic control system for artificial organs had been developed for the ventricular assist devices including a rotary blood pump to avoid suction and to maintain left and right heart balance. Based upon the technology of automatic control algorithm, a new diagnostic tool for evaluating autonomic nerve function has been developed as a branch of artificial organ research and this new machine has been tested in Tohoku University Hospital. Tohoku University is following a variety of approaches aimed at innovation in artificial organs and medical engineering fields.

  12. Organic air pollutants: setting priorities for long term research needs. A workshop sponsored by the United States Department of Energy, April 19-23, 1982, Gettysburg, PA

    SciTech Connect

    Gaffney, J.S.

    1982-04-01

    The workshop attempted to outline and prioritize current and future research dealing with the environmental and biomedical concern of organic air pollutants. The meeting addressed the following four main areas of research: chemical and physical characterization of source emissions and ambient levels of organic pollutants; atmospheric chemical and physical transformations (homogeneous and heterogeneous) of organic pollutants; biochemical testing procedures to determine potential biological and human health impacts; and air quality - dispersion simulation and source/receptor modeling as tools in assessing potential biomedical and geophysical impacts of organic air pollutants. Details of each discussion group's deliberations and recommendations are summarized.

  13. 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.

  14. 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

  15. Changes in soil chemical and microbiological properties during 4 years of application of various organic residues.

    PubMed

    Odlare, M; Pell, M; Svensson, K

    2008-01-01

    A 4-year field trial was established in eastern Sweden to evaluate the effects of organic waste on soil chemical and microbiological variables. A simple crop rotation with barley and oats was treated with either compost from household waste, biogas residue from household waste, anaerobically treated sewage sludge, pig manure, cow manure or mineral fertilizer. All fertilizers were amended in rates corresponding to 100kgNha(-1)year(-1). The effects of the different types of organic waste were evaluated by subjecting soil samples, taken each autumn 4 weeks after harvest, to an extensive set of soil chemical (pH, Org-C, Tot-N, Tot-P, Tot-S, P-AL, P-Olsen, K-AL, and some metals) and microbiological (B-resp, SIR, microSIR active and dormant microorganisms, PDA, microPDA, PAO, Alk-P and N-min) analyses. Results show that compost increased pH, and that compost as well as sewage sludge increased plant available phosphorus; however, the chemical analysis showed few clear trends over the 4 years and few clear relations to plant yield or soil quality. Biogas residues increased substrate induced respiration (SIR) and, compared to the untreated control amendment of biogas residues as well as compost, led to a higher proportion of active microorganisms. In addition, biogas residues increased potential ammonia oxidation rate (PAO), nitrogen mineralization capacity (N-min) as well as the specific growth rate constant of denitrifiers (microPDA). Despite rather large concentrations of heavy metals in some of the waste products, no negative effects could be seen on either chemical or microbiological soil properties. Changes in soil microbial properties appeared to occur more rapidly than most chemical properties. This suggests that soil microbial processes can function as more sensitive indicators of short-term changes in soil properties due to amendment of organic wastes. PMID:17697770

  16. 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.

  17. 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.

  18. 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.

  19. All-organic microelectromechanical systems integrating specific molecular recognition--a new generation of chemical sensors.

    PubMed

    Ayela, Cédric; Dubourg, Georges; Pellet, Claude; Haupt, Karsten

    2014-09-01

    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.

  20. 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.

  1. 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.

  2. Accounting for natural organic matter in aqueous chemical equilibrium models: a review of the theories and applications

    NASA Astrophysics Data System (ADS)

    Dudal, Yves; Gérard, Frédéric

    2004-08-01

    Soil organic matter consists of a highly complex and diversified blend of organic molecules, ranging from low molecular weight organic acids (LMWOAs), sugars, amines, alcohols, etc., to high apparent molecular weight fulvic and humic acids. The presence of a wide range of functional groups on these molecules makes them very reactive and influential in soil chemistry, in regards to acid-base chemistry, metal complexation, precipitation and dissolution of minerals and microbial reactions. Out of these functional groups, the carboxylic and phenolic ones are the most abundant and most influential in regards to metal complexation. Therefore, chemical equilibrium models have progressively dealt with organic matter in their calculations. This paper presents a review of six chemical equilibrium models, namely N ICA-Donnan, E Q3/6, G EOCHEM, M INTEQA2, P HREEQC and W HAM, in light of the account they make of natural organic matter (NOM) with the objective of helping potential users in choosing a modelling approach. The account has taken various faces, mainly by adding specific molecules within the existing model databases (E Q3/6, G EOCHEM, and P HREEQC) or by using either a discrete (W HAM) or a continuous (N ICA-Donnan and M INTEQA2) distribution of the deprotonated carboxylic and phenolic groups. The different ways in which soil organic matter has been integrated into these models are discussed in regards to the model-experiment comparisons that were found in the literature, concerning applications to either laboratory or natural systems. Much of the attention has been focused on the two most advanced models, W HAM and N ICA-Donnan, which are able to reasonably describe most of the experimental results. Nevertheless, a better knowledge of the humic substances metal-binding properties is needed to better constrain model inputs with site-specific parameter values. This represents the main axis of research that needs to be carried out to improve the models. In addition to

  3. Significance of Xenobiotic Metabolism for Bioaccumulation Kinetics of Organic Chemicals in Gammarus pulex

    PubMed Central

    2012-01-01

    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 14C-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 14C 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. PMID:22321051

  4. Organization of early frog embryos by chemical waves emanating from centrosomes.

    PubMed

    Ishihara, Keisuke; Nguyen, Phuong A; Wühr, Martin; Groen, Aaron C; Field, Christine M; Mitchison, Timothy J

    2014-09-01

    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

  5. 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

  6. 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.

  7. Organic Nitrogen in Atmospheric Drops and Particles: Concentrations, (Limited) Speciation, and Chemical Transformations

    NASA Astrophysics Data System (ADS)

    Anastasio, C.; Zhang, Q.

    2003-12-01

    While quite a bit is known of the concentrations, speciation, and chemistry of inorganic forms of nitrogen in the atmosphere, the same cannot be said for organic forms. Despite this, there is growing evidence that organic N (ON) is ubiquitous in the atmosphere, especially in atmospheric condensed phases such as fog/cloud drops and aerosol particles. Although the major compounds that make up organic N are generally unknown, as are the sources of these compounds, it is clear that there are significant fluxes of ON between the atmosphere and ecosystems. It also appears that organic N can have significant effects in both spheres. The goal of our recent work in this area has been to better describe the atmospheric component of the biogeochemistry of organic nitrogen. Based on particle, gas, and fogwater samples from Northern California we have made three major findings: 1) Organic N represents a significant component, approximately 20%, of the total atmospheric N loading in these samples. This is broadly consistent with studies from other locations. 2) Amino compounds, primarily as combined amino acids, account for approximately 20% of the measured ON in our condensed phase samples. Given the properties of amino acids, these compounds could significantly affect the chemical and physical properties of atmospheric particles. 3) Organic nitrogen in atmospheric particles and drops is transformed to inorganic forms - primarily ammonium, nitrate, and nitrogen oxides (NOx) - during exposure to sunlight and/or ozone. These chemical reactions likely increase the bioavailability of the condensed phase nitrogen pool and enhance its biological effects after deposition to ecosystems.

  8. Effects of Chemical Aging on the Heterogeneous Freezing of Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Collier, K.; Brooks, S. D.

    2014-12-01

    Organic aerosols are emitted into the atmosphere from a variety of sources and display a wide range of effectiveness in promoting the nucleation of ice in clouds. Soot and polycyclic aromatic hydrocarbons (PAHS) arise from incomplete combustion and other pollutant sources. Hydrocarbon compounds in diesel motor oil and other fuel blends include compounds such as octacosane (a straight saturated alkane), squalane (a branched saturated alkane) and squalene (an unsaturated branched alkene). At temperatures above -36°C, the formation of ice crystals in the atmosphere is facilitated by heterogeneous freezing processes in which atmospheric aerosols act as ice nuclei (IN). The variability in ability of organic particles to facilitate heterogeneous ice nucleation causes major uncertainties in predictions of aerosol effects on climate. Further, atmospheric aerosol composition and ice nucleation ability can be altered via chemical aging and reactions with atmospheric oxidants such as ozone. In this study, we take a closer look at the role of chemical oxidation on the efficiency of specific IN during contact freezing laboratory experiments. The freezing temperatures of droplets in contact with representative organic aerosols are determined through the use of an optical microscope apparatus equipped with a cooling stage and a digital camera. Chemical changes at the surface of aerosols due to ozone exposure are characterized using Raman Microspectroscopy and Fourier Transform Infrared Spectroscopy with Horizontal Attenuated Total Reflectance. Our results indicate that oxidation of certain atmospheric organics (soot and PAHS) enhances their ice nucleation ability. In this presentation, results of heterogeneous nucleation on various types of organic aerosols will be presented, and the role of structure in promoting freezing will be discussed.

  9. 78 FR 70560 - Patient Safety Organizations: Voluntary Relinquishment From Morgridge Institute for Research PSO

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... HUMAN SERVICES Agency for Healthcare Research and Quality Patient Safety Organizations: Voluntary Relinquishment From Morgridge Institute for Research PSO AGENCY: Agency for Healthcare Research and Quality (AHRQ... Safety Organizations (PSOs), which collect, aggregate, and analyze confidential information regarding...

  10. Bioassay-directed chemical analysis in environmental research

    SciTech Connect

    Schuetzle, D.; Lewtas, J.

    1986-01-01

    The use of short-term bioassay tests in conjunction with analytical measurements, constitute a powerful tool for identifying important environmental contaminants. The authors have coined the terminology bioassay directed chemical analysis to best describe this marriage of analytical chemistry and biology. The objective of this methodology is to identify key compounds in various types of air-pollutant samples. Once that task is completed, studies on metabolism, sources, environmental exposure and atmospheric chemistry can be undertaken. The principles and methodologies for bioassay directed chemical analysis are presented and illustrated in this paper. Most of this work has been directed toward the characterization of ambient air and diesel particulates, which are used as examples in this report to illustrate the analytical logic used for identifying the bio-active components of complex mixtures.

  11. 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.

  12. 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.

  13. Evaluation of Volatilization by Organic Chemicals Residing Below the Soil Surface

    NASA Astrophysics Data System (ADS)

    Jury, William A.; Russo, David; Streile, Gary; El Abd, Hesham

    1990-01-01

    Although volatile organic compounds located in buried waste repositories or distributed through the unsaturated soil zone have the potential to migrate to the atmosphere by vapor diffusion, little attention has been paid in the past to estimating the importance of volatilization losses. In this paper a screening model is introduced which evaluates the relative volatilization losses of a number of organic compounds under standard soil conditions. The model is an analytic solution to the problem wherein the organic chemical is located at time zero at uniform concentration in a finite layer of soil covered by a layer of soil devoid of chemical. The compound is assumed to move by vapor or liquid diffusion and by mass flow under the influence of steady upward or zero water flow while undergoing first-order degradation and linear equilibrium adsorption. Loss to the atmosphere is governed by vapor diffusion through a stagnant air boundary layer. Calculations are performed on 35 organic compounds in two model soils with properties characteristic of sandy and clayey soil. The model identifies those compounds with high potential for loss during 1 year after incorporation under 100 cm of soil cover and also is used to calculate the minimum soil cover thickness required to reduce volatilization losses to insignificant levels during the lifetime of the compound in the soil. From the latter calculation it was determined that certain compounds may volatilize from deep subsurface locations or even groundwater unless the soil surface is sealed to prevent gas migration.

  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. 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.

  16. [Quantification assessment of the relationship between chemical and olfactory concentrations for malodorous volatile organic compounds].

    PubMed

    Liu, Shu-Le; Wang, Bo-Guang; He, Jie; Tang, Xiao-Dong; Zhao, De-Jun; Guo, Wei

    2011-12-01

    Using self-made cold-traps and gas bags, the odor samples were collected from 6 sewage treatment workshops of a typical municipal sewage treatment plant in Guangzhou City. The chemical composition and olfactory concentrations of these samples were respectively analyzed by thermal-desorption/GC-MS and triangle odor bag method. Finally, a mathematical equation was built for assessing the relationship between principal organic odorants and the olfactory concentrations. The result showing that: (1) More than 70 volatile organic compounds were detected in municipal sewage treatment plant, among which were 30 malodorous volatile organic compounds (MVOCs), ranging from 0.37 to 1 872.24 microg x m(-3) and appearing in sludge dewatering, thickening and aeration tank with the highest concentrations. (2) Principle component analysis was used to group the target MVOCs into 5 categories: benzenes, halohydrocarbons, aldehydes, hydrocarbons and S, N-containing organic compounds. (3) Multiple lineal regression analysis was used to build a quantified relationship between chemical and olfactory concentrations of MVOCs. The result indicated that 25% of the odor problem of sewage treatment unit was due to MVOCs. The predicted values were fitting well with measured values. The sensitivity of mathematical equation for measuring odor concentration was higher than that of human olfactory system.

  17. Ultra-Stable Organic Fluorophores for Single-Molecule Research

    PubMed Central

    Zheng, Qinsi; Juette, Manuel F.; Jockusch, Steffen; Wasserman, Michael R.; Zhou, Zhou; Altman, Roger B.; Blanchard, Scott C.

    2013-01-01

    Fluorescence provides a mechanism for achieving contrast in biological imaging that enables investigations of molecular structure, dynamics, and function at high spatial and temporal resolution. Small-molecule organic fluorophores have proven essential for such efforts and are widely used in advanced applications such as single-molecule and super-resolution microscopy. Yet, organic fluorophores, like all fluorescent species, exhibit instabilities in their emission characteristics, including blinking and photobleaching that limit their utility and performance. Here, we review the photophysics and photochemistry of organic fluorophores as they pertain to mitigating such instabilities, with a specific focus on the development of stabilized fluorophores through derivatization. Self-healing organic fluorophores, wherein the triplet state is intramolecularly quenched by a covalently attached protective agent, exhibit markedly improved photostabilities. We discuss the potential for further enhancements towards the goal of developing “ultra-stable” fluorophores spanning the visible spectrum and how such fluorophores are likely to impact the future of single-molecule research. PMID:24177677

  18. 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

  19. Compound prioritization methods increase rates of chemical probe discovery in model organisms.

    PubMed

    Wallace, Iain M; Urbanus, Malene L; Luciani, Genna M; Burns, Andrew R; Han, Mitchell K L; 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

    2011-10-28

    Preselection 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 Saccharomyces cerevisiae and identified ~7500 that inhibit cell growth. Screening these growth-inhibitory molecules across a diverse panel of model organisms resulted in an increased phenotypic hit-rate. These data were 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 ~7500 growth-inhibitory molecules have been made commercially available and the computational model and filter used are provided.

  20. Typology of exogenous organic matters based on chemical and biochemical composition to predict potential nitrogen mineralization.

    PubMed

    Lashermes, G; Nicolardot, B; Parnaudeau, V; Thuriès, L; Chaussod, R; Guillotin, M L; Linères, M; Mary, B; Metzger, L; Morvan, T; Tricaud, A; Villette, C; Houot, S

    2010-01-01

    Our aim was to develop a typology predicting potential N availability of exogenous organic matters (EOMs) in soil based on their chemical characteristics. A database of 273 EOMs was constructed including analytical data of biochemical fractionation, organic C and N, and results of N mineralization during incubation of soil-EOM mixtures in controlled conditions. Multiple factor analysis and hierarchical classification were performed to gather EOMs with similar composition and N mineralization behavior. A typology was then defined using composition criteria to predict potential N mineralization. Six classes of EOM potential N mineralization in soil were defined, from high potential N mineralization to risk of inducing N immobilization in soil after application. These classes were defined on the basis of EOM organic N content and soluble, cellulose-, and lignin-like fractions. A decision tree based on these variables was constructed in order to easily attribute any EOM to 1 of the 6 classes. PMID:19726180

  1. Chemical and carbon isotopic composition of dissolved organic carbon in a regional confined methanogenic aquifer

    USGS Publications Warehouse

    Aravena, R.; Wassenaar, L.I.; Spiker, E. C.

    2004-01-01

    This study demonstrates the advantage of a combined use of chemical and isotopic tools to understand the dissolved organic carbon (DOC) cycle in a regional confined methanogenic aquifer. DOC concentration and carbon isotopic data demonstrate that the soil zone is a primary carbon source of groundwater DOC in areas close to recharge zones. An in-situ DOC source linked to organic rich sediments present in the aquifer matrix is controlling the DOC pool in the central part of the groundwater flow system. DOC fractions, 13C-NMR on fulvic acids and 14C data on DOC and CH4 support the hypothesis that the in-situ DOC source is a terrestrial organic matter and discard the Ordovician bedrock as a source of DOC. ?? 2004 Taylor and Francis Ltd.

  2. Chemical Research and Instruction in Zürich, 1833-1872.

    PubMed

    Ramberg, Peter J

    2015-04-01

    The development of universities and technical schools in nineteenth century Switzerland is commonly assumed to be similar to the development of comparable schools in Germany. To a large extent this is correct, but there are subtle differences in the founding and organization of Swiss institutions that are reflective of the Swiss national and local cantonal contexts. In the case of Zürich, the specific local political and financial conditions underlying the formation of the University of Zürich, the Zürich Cantonal School and the Swiss Federal Polytechnic resulted in a complex set of dual appointments and shared facilities that were absent at comparable chemical laboratories at German universities. This essay outlines the origins of these complex relationships under Carl Löwig (1833-1853) and Georg Städeler (1853-1870) and follows in more detail the complex career path of Johannes Wislicenus in Zürich from his appointment as Privatdozent in 1860 to his appointment as Director of the Polytechnic in 1871. Wislicenus' career path illustrates the institutional context of chemistry in Zürich and shows how this context, including the roles of cantonal and federal support, and the physical constraints created by shared laboratory facilities, shaped chemical research and instruction in Zürich.

  3. Identification of specific organic contaminants in different units of a chemical production site.

    PubMed

    Dsikowitzky, L; Botalova, O; al Sandouk-Lincke, N A; Schwarzbauer, J

    2014-07-01

    Due to the very limited number of studies dealing with the chemical composition of industrial wastewaters, many industrial organic contaminants still escape our view and consequently also our control. We present here the chemical characterization of wastewaters from different units of a chemical complex, thereby contributing to the characterization of industrial pollution sources. The chemicals produced in the investigated complex are widely and intensively used and the synthesis processes are common and applied worldwide. The chemical composition of untreated and treated wastewaters from the chemical complex was investigated by applying a non-target screening which allowed for the identification of 39 organic contaminants. According to their application most of them belonged to four groups: (i) unspecific educts or intermediates of industrial syntheses, (ii) chemicals for the manufacturing of pharmaceuticals, (iii) educts for the synthesis of polymers and resins, and (iv) compounds known as typical constituents of municipal sewage. A number of halogenated compounds with unknown toxicity and with very high molecular diversity belonged to the second group. Although these compounds were completely removed or degraded during wastewater treatment, they could be useful as "alarm indicators" for industrial accidents in pharmaceutical manufacturing units or for malfunctions of wastewater treatment plants. Three potential branch-specific indicators for polymer manufacturing were found in the outflow of the complex. Among all compounds, bisphenol A, which was present in the leachate water of the on-site waste deposit, occurred in the highest concentrations of up to 20 000 μg L(-1). The comparison of contaminant loads in the inflow and outflow of the on-site wastewater treatment facility showed that most contaminants were completely or at least significantly removed or degraded during the treatment, except two alkylthiols, which were enriched during the treatment process

  4. European research on cell and organ transplantation: towards novel opportunities?

    PubMed

    Goldman, Michel; Wood, Kathryn

    2007-12-01

    Recent developments in basic and translational immunology open new exciting perspectives for clinical cell and organ transplantation, including the development of novel immunosuppressive agents, new diagnostic tools and validation of biomarkers for the prediction of rejection as well as the induction of tolerance. With respect to tolerance, a number of hurdles still need to be overcome before immunosuppressive drugs can be safely minimized or withdrawn in solid organ transplant recipients. Indeed, the human immune system appears more resistant to tolerance induction than expected from experimental studies in animals. Furthermore, the basic ethical principle 'primum non-nocere' prevents the implementation of clinical protocols endowed with a significant risk for graft and/or patient survival. With this background, the European Commission recently launched several initiatives to tackle unmet needs in transplantation medicine. Herein, we focus attention on the ongoing collaborative effort across the European Union aiming at identifying the current priorities requiring better integration of resources dedicated to transplantation research. PMID:17803662

  5. Researchers Find Order, Beauty in Chaotic Chemical Systems.

    ERIC Educational Resources Information Center

    Borman, Stu

    1991-01-01

    Deterministic chaos which involves orderly motion is discussed. Presented is the history of chaos and two tests for chaos. Practical applications and predictions of the long-term significance of chaos research are discussed. (KR)

  6. Molecular corridors and kinetic regimes in the multiphase chemical evolution of secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Shiraiwa, M.; Berkemeier, T.; Schilling-Fahnestock, K. A.; Seinfeld, J. H.; Pöschl, U.

    2014-08-01

    The dominant component of atmospheric, organic aerosol is that derived from the oxidation of volatile organic compounds (VOCs), so-called secondary organic aerosol (SOA). SOA consists of a multitude of organic compounds, only a small fraction of which has historically been identified. Formation and evolution of SOA is a complex process involving coupled chemical reaction and mass transport in the gas and particle phases. Current SOA models do not embody the full spectrum of reaction and transport processes, nor do they identify the dominant rate-limiting steps in SOA formation. Based on molecular identification of SOA oxidation products, we show here that the chemical evolution of SOA from a variety of VOC precursors adheres to characteristic "molecular corridors" with a tight inverse correlation between volatility and molar mass. The slope of these corridors corresponds to the increase in molar mass required to decrease volatility by one order of magnitude (-dM / dlogC0). It varies in the range of 10-30 g mol-1, depending on the molecular size of the SOA precursor and the O : C ratio of the reaction products. Sequential and parallel reaction pathways of oxidation and dimerization or oligomerization progressing along these corridors pass through characteristic regimes of reaction-, diffusion-, or accommodation-limited multiphase chemical kinetics that can be classified according to reaction location, degree of saturation, and extent of heterogeneity of gas and particle phases. The molecular corridors and kinetic regimes help to constrain and describe the properties of the products, pathways, and rates of SOA evolution, thereby facilitating the further development of aerosol models for air quality and climate.

  7. Molecular corridors and kinetic regimes in the multiphase chemical evolution of secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Shiraiwa, M.; Berkemeier, T.; Schilling-Fahnestock, K.; Seinfeld, J.; Poeschl, U.

    2014-12-01

    The dominant component of atmospheric organic aerosol is that derived from the oxidation of volatile organic compounds (VOCs), so-called secondary organic aerosol (SOA). SOA consists of a multitude of organic compounds, only a small fraction of which has historically been identified. Formation and evolution of SOA is a complex process involving coupled chemical reaction and mass transport in the gas and particle phases. Current SOA models do not embody the full spectrum of reaction and transport processes nor do they identify the dominant rate-limiting steps in SOA formation. Based on molecular identification of SOA oxidation products, we show here that the chemical evolution of SOA from a variety of VOC precursors adheres to characteristic "molecular corridors" with a tight inverse correlation between volatility and molar mass. The slope of these corridors corresponds to the increase in molar mass required to decrease volatility by one order of magnitude (-dM/dlogC0). It varies in the range of 10-30 g mol-1 depending on the molecular size of the SOA precursor and the O:C ratio of the reaction products. Sequential and parallel reaction pathways of oxidation and dimerization or oligomerization progressing along these corridors pass through characteristic regimes of reaction-, diffusion-, or accommodation-limited multiphase chemical kinetics that can be classified according to reaction location, degree of saturation, and extent of heterogeneity of gas and particle phases. The molecular corridors and kinetic regimes help to constrain and described the properties of the products, pathways and rates of SOA evolution, thereby facilitating the further development of aerosol models for air quality and climate.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  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. 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.

  14. 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. PMID:27372890

  15. 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.

  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. NCCR Chemical Biology: Interdisciplinary Research Excellence, Outreach, Education, and New Tools for Switzerland.

    PubMed

    Sturzenegger, Susi; Johnsson, Kai; Riezman, Howard

    2011-01-01

    Funded by the Swiss National Science Foundation to promote cutting edge research as well as the advancement of young researchers and women, technology transfer, outreach and education, the NCCR (Swiss National Centre of Competence in Research) Chemical Biology is co-led by Howard Riezman, University of Geneva and Kai Johnsson, École Polytechnique Fédérale de Lausanne (EPFL).

  18. 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

  19. 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. PMID:20543892

  20. 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.

  1. 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

  2. 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. PMID:26934738

  3. 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.

  4. 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.

  5. Assessment of tissue concentrations of metals and volatile organic chemicals in farm animal products

    SciTech Connect

    Stone, P.R. III; Shortelle, A.B.; Charna, R.; Maxwell, J.

    1995-12-31

    An Army site in Pennsylvania is included on the National Priorities List. Site-related chemicals such as volatile organic chemicals (VOCs) and metals have been released to the groundwater from the industrial sewer which have now been repaired. VOCs are also present in groundwater in off post residential wells. The purpose of this study was to address the possible effects of groundwater and surface water chemicals to livestock and humans via the food chain pathway in the off post areas. Sampling of off post farm animal tissues was performed to confirm or revise the conclusion (based on modeled results) that this exposure pathway does not pose significant risk to human or animal health. Objectives of this study were to: (1) determine the potential presence of study constituents in the components of the food chain, and (2) develop data for use in the future risk assessment. Samples collected from the study area and reference (background) areas include beef (4 cuts), poultry, eggs, pork (5 cuts), and cow`s milk. The analyses were performed using published EPA methodologies modified as appropriate for sample (tissue) preparation. VOCs were analyzed using the EPA GC/MS purge and trap method SW846-8240. Metals were analyzed using the EPA inductively coupled/mass spectrometer (ICP/MS) method SW846-6020. Metals were found ubiquitously in samples from both areas. VOCs were only sporadically found. Statistical analyses were performed to identify chemicals in specific tissues where concentrations differed significantly between study area and reference areas.

  6. 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. PMID:26010172

  7. [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. PMID:22720548

  8. 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.

  9. 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.

  10. 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…

  11. Comparing Linear Free Energy Relationships for Organic Chemicals in Soils: Effects of Soil and Solute Properties

    PubMed Central

    Faria, Isabel R.; Young, Thomas M.

    2010-01-01

    Sorption isotherm data were determined for a set of 8 aromatic organic compounds with varying physical chemical properties in three soils with organic matter of differing quantity and composition. The primary goals of this study were to test single and multi-parameter linear free energy relationships on their ability to predict the observed sorption behavior on different types of natural sorbents across a range of solutes and concentrations and to relate the accuracy of the predictions to sorbent and solute structural descriptors. Organic carbon normalized sorption coefficients (KOC) predicted using both single and multi-parameter LFERs were in good agreement with experimental data obtained at the highest tested aqueous concentrations (average deviation less than 0.1 log units over all solutes and sorbents) but deviations were more substantial (0.59–0.65 log units) at the lowest tested concentrations. For chlorinated benzenes there was a significant correlation between experiment-prediction discrepancies and the aromatic content of the soil organic matter measured by 13C NMR and the magnitude of the effect was similar to that observed previously for dissolved organic matter. PMID:20726509

  12. [Toxicology of chemical substances (metals and organic solvents): management as an occupational physician].

    PubMed

    Ueno, Susumu

    2013-10-01

    Even in Japan, there was a time when cases of occupational poisoning had frequently occurred, which led to the enactment of the Industrial Safety and Health Act in 1972. Currently, the use of only a part of chemical substances utilized in the workplace is regulated according to their designated hazardous level, but there are many other substances whose toxicities have not been elucidated. Risk assessment is now required of entrepreneurs in all categories of industry by the recently-revised Industrial Safety and Health Act. This article will focus on the toxicology of metals and organic solvents, and it will discuss how occupational physicians should manage chemicals, including the ones whose toxicities have not been clarified. PMID:24107340

  13. 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. PMID:25712694

  14. 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

  15. 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)

  16. 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.

  17. 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.

  18. [Soil organic carbon fractionation methods and their applications in farmland ecosystem research: a review].

    PubMed

    Zhang, Guo; Cao, Zhi-ping; Hu, Chan-juan

    2011-07-01

    Soil organic carbon is of heterogeneity in components. The active components are sensitive to agricultural management, while the inert components play an important role in carbon fixation. Soil organic carbon fractionation mainly includes physical, chemical, and biological fractionations. Physical fractionation is to separate the organic carbon into active and inert components based on the density, particle size, and its spatial distribution; chemical fractionation is to separate the organic carbon into various components based on the solubility, hydrolizability, and chemical reactivity of organic carbon in a variety of extracting agents. In chemical fractionation, the dissolved organic carbon is bio-available, including organic acids, phenols, and carbohydrates, and the acid-hydrolyzed organic carbon can be divided into active and inert organic carbons. Simulated enzymatic oxidation by using KMnO4 can separate organic carbon into active and non-active carbon. Biological fractionation can differentiate microbial biomass carbon and potential mineralizable carbon. Under different farmland management practices, the chemical composition and pool capacity of soil organic carbon fractions will have different variations, giving different effects on soil quality. To identify the qualitative or quantitative relationships between soil organic carbon components and carbon deposition, we should strengthen the standardization study of various fractionation methods, explore the integrated application of different fractionation methods, and sum up the most appropriate organic carbon fractionation method or the appropriate combined fractionation methods for different farmland management practices. PMID:22007474

  19. 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.

  20. 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