COMPOSITION of water, POLYMERS, CATALYSTS, INORGANIC chemistry, and POWER resources
The article discusses research on how the light-induced splitting of water into oxygen and hydrogen generates storable polymers and chemical fuels that could be used to address the world's energy demands. Particular attention is also given to the use of inorganic materials as semiconductor catalysts for such splits.
The application of alternating current is advantageous in energy transfer over long distances. It is a well-known fact now, but subject of long conflict in the era of pioneering works in electric power production. There are also some processes in physical chemistry, organic and inorganic chemistry, in biochemistry and related sciences, which take place in opposite directions, with consecutive alternations in time. However, the very existence of alternate reactions, now known as the oscillatory or oscillating reactions, has long been disputed because it was thought that it is contrary to the basic principles of thermodynamics. Nevertheless, according to our knowledge, there are no oscillatory reactions without catalytic loop as the essential part of a mechanism. There could be a fundamental rule that catalysis is necessary to generate oscillations in concentrations and reaction rates. Particularly, homogeneous oscillatory reactions are often subject of research as relatively simple systems with good chance to clearly define feedbacks responsible for instability phenomena. However, oscillations can at least equally often be found in heterogeneous catalytic reactions. Recently, changes in product selectivity was proved when Pd catalyzed carbonylation of phenylacetylene was moved to the oscillatory dynamic state. With this simple result, the doors are now open for wide spectrum of research projects and applications. [ABSTRACT FROM AUTHOR]
Patterns of co-authorship provide an effective means of probing the structures of research communities. In this paper, we use the CiteSpace social network tool and co-authorship data from the Web of Science to analyse two such types of community. The first type is based on the cited publications of a group of highly productive authors in a particular discipline, and the second on the uncited publications of those highly productive authors. These pairs of communities were generated for three different countries—the People's Republic of China (PRC), the United Kingdom (UK) and the United States of America (USA)—and for four different disciplines (as denoted by Web of Science subject categories)—Chemistry Organic, Engineering Environmental, Economics, and Management. In the case of the UK and USA, the structures of the cited and uncited communities in each of the four disciplines were markedly different from each other; in the case of the PRC, conversely, the cited and uncited PRC communities had broadly similar structures that were characterised by large groups of connected authors. We suggest that this may arise from a greater degree of guest or honorary authorship in the PRC than in the UK or the USA. [ABSTRACT FROM AUTHOR]
VOLATILE organic compounds, OPTICAL properties of atmospheric aerosols, ATMOSPHERIC chemistry, ATMOSPHERIC research, HYDROCARBONS, GLOBAL temperature changes, and MOUNTAINS -- United States
Mean temperature anomalies in the Southeastern United States (SEUS) over the past century have reflected regional cooling hypothesized to be a result of an enhancement of warm season aerosol optical thickness caused by the oxidation of biogenic volatile organic compounds (VOCs). Aerosol and gas-phase VOC measurements were made at the Appalachian Atmospheric Interdisciplinary Research (AppalAIR) site in the southern Appalachian mountains of North Carolina during the summer of 2013 in an effort to characterize warm season chemistry. Organic aerosol (OA) chemistry was characterized through a positive matrix factorization analysis resolving a low-volatility, semi-volatile, and isoprene oxidation factor contributing 34 ± 15, 24 ± 12, and 42 ± 17 %, respectively to the total observed OA. Volatile organic compound characterization described chemistry that was typical of rural background levels with periods of elevated hydrocarbon and urban tracer loading that varied with synoptic flow. Chemical, meteorological, and aerosol optical property data suggested that measurements made at the AppalAIR site are representative of background atmospheric chemistry in the SEUS. Annual background secondary organic aerosol (SOA) production in the SEUS was estimated to be 0.15-0.50 GgC yr. Estimates of total and background SOA from this study provide evidence that the SEUS is a region of global significance in the context of global SOA budgets, and can be useful in understanding the extent of anthropogenic enhancement of summertime SOA compared to background levels. [ABSTRACT FROM AUTHOR]
STREAM chemistry, WATER quality, PHOSPHORUS in water, ORTHOPHOSPHATES, BIOCHEMICAL oxygen demand, WATER pollution, FACTOR analysis, and ANTHROPOGENIC effects on nature
Anthropogenic activities have led to water quality deterioration in many parts of the world, especially in Northeast China. The current work investigated the spatiotemporal variations of water quality in the Taizi River by multivariate statistical analysis of data from the 67 sampling sites in the mainstream and major tributaries of the river during dry and rainy seasons. One-way analysis of variance indicated that the 20 measured variables (except pH, 5-day biological oxygen demand, permanganate index, and chloride, orthophosphate, and total phosphorus concentrations) showed significant seasonal ( p ≤ 0.05) and spatial ( p < 0.05) variations among the mainstream and major tributaries of the river. Hierarchical cluster analysis of data from the different seasons classified the mainstream and tributaries of the river into three clusters, namely, less, moderately, and highly polluted clusters. Factor analysis extracted five factors from data in the different seasons, which accounted for the high percentage of the total variance and reflected the integrated characteristics of water chemistry, organic pollution, phosphorous pollution, denitrification effect, and nitrogen pollution. The results indicate that river pollution in Northeast China was mainly from natural and/or anthropogenic sources, e.g., rainfall, domestic wastewater, agricultural runoff, and industrial discharge. [ABSTRACT FROM AUTHOR]
ORGANIC chemistry research, CHEMICAL synthesis, METAL complexes, CATALYSIS, CHEMISTS, and SCIENTISTS
The article comments on the article "The Reasons Organic Chemistry is Needed for in a Well Developed Country," by I.P. Beletskaya and V.P. Ananikov, published in this journal. It discusses need for a strong effort to get positive results in the fields of Russian chemistry, organic synthesis, and metal complex catalysis; need for the development of new methods and reactions for the formation of desired materials; and role of young researchers in the development of organic chemistry in Russia.
SCIENCE CHINA Chemistry; May2012, Vol. 55 Issue 5, p648-676, 29p
Self-healing polymers represent a class of materials with built-in capability of rehabilitating damages. The topic has attracted increasingly more attention in the past few years. The on-going research activities clearly indicate that self-healing polymeric materials turn out to be a typical multi-disciplinary area concerning polymer chemistry, organic synthesis, polymer physics, theoretical and experimental mechanics, processing, composites manufacturing, interfacial engineering, etc. The present article briefly reviews the achievements of the groups worldwide, and particularly the work carried out in our own laboratory towards strength recovery for structural applications. To ensure sufficient coverage, thermoplastics and thermosetting polymers, extrinsic and intrinsic self-healing, autonomic and non-autonomic healing approaches are included. Innovative routes that correlate materials chemistry to full capacity restoration are discussed for further development from bioinspired toward biomimetic repair. [ABSTRACT FROM AUTHOR]
Atmospheric black carbon (BC) has a strong positive, but still controversial, effect on global warming. In particular, BC absorption enhancement (Eabs) due to internal mixing with other chemical species—so-called lensing effect—is poorly assessed. This bottleneck partly relies on the lack of long-term in situ measurements of both the optical and chemical properties of BC-containing particles. Here, we present experimental and computational results showing a significant Eabs increase with the aerosol photochemical aging. This was associated with the production of highly oxidized secondary organic aerosols (SOA), especially at summertime. The 3-year-long continuous aerosol chemical and optical measurements used for the present study was obtained in the Paris region, France, which might be representative of near-future air quality within developing countries. These findings suggest that SOA could represent one of the most critical chemical species to be considered within climate models. Atmospheric chemistry: organic aerosols amplify atmospheric warming from black carbon Tiny remnants of combustion, known as black carbon, absorb solar radiation and warm the atmosphere—an effect that can be doubled by "lensing" from secondary organic aerosols. A multi-institution team led by Olivier Favez at the Institut National de l'Environnement Industriel et des Risques conducted a three-year observational and modeling study near Paris. The researchers tested a range of atmospheric constituents and found that secondary organic aerosols—adhered to black carbon particles—are the most important determinant of the enhanced warming. The aerosols are produced by photochemical reactions with a wide variety of natural and human-produced volatile organic compounds, and act to focus solar radiation to the core of the black carbon particle, especially during the particle aging process during summer. The findings—although specific to Paris—provide insights into the specific compounds leading to enhanced warming, and reveal the most effective targets for remediating their effect. [ABSTRACT FROM AUTHOR]
Catalysis in Industry; Sep2010, Vol. 2 Issue 3, p199-205, 7p
The present and prospective use of precious metals (platinum and palladium) in catalyst production is analyzed with allowance made for the appearance of new catalytic technologies. The production of precious metal catalysts in Russia is now being curtailed. Russian companies are reconstructing plants that employ precious metal catalysts and bulding new ones in cooperation with foreign partners who will provide advanced technologies and the necessary catalysts. The proportion of imported palladium- and platinum-containing catalysts in Russia remains rather high (as much as 60%). The consumption of precious metals in organic synthesis and in the pharmaceutical industry remains at the level of the 1990s. In this overview, we analyze the possibilities for the wider use of platinum in the design of novel catalysts that could compete with imported analogues, including those for petroleum refining, petroleum chemistry, organic synthesis, and environmental applications. We also cover new areas for Russia: nanocomposites for hydrogen energy, new drugs, and membrane technologies. [ABSTRACT FROM AUTHOR]
Woodcock, Thomas S., Monaghan, Megan C., and Alexander, Karen E.
Wetlands; Jun2010, Vol. 30 Issue 3, p461-474, 14p, 1 Black and White Photograph, 2 Diagrams, 5 Charts, 1 Graph
Stormwater ponds (SWPs) are wetlands created or engineered for the purpose of collecting and controlling urban runoff, sediments, and toxins prior to discharging into other surface and/or ground waters. As wetlands face increasing pressure from development, many SWPs are also considered by planners as a valid solution to the problem of wetland habitat loss. This study compares water chemistry, organic matter dynamics, and macroinvertebrate community structure, biomass, and secondary productivity in a sample of SWPs with nearby reference wetlands of natural origin. Although total secondary productivity of invertebrates was greater in SWPs, significant differences were observed in water chemistry, invertebrate community structure, invertebrate biomass turnover, and organic matter dynamics that suggest that the SWPs were not comparable to the reference wetlands from the point of view of ecosystem function and conservation. Furthermore, improvement in the function of SWPs in pollutant control might be achieved by improving their function in conservation, most notably by considering the role of organic matter inputs from adjacent terrestrial areas in the planning. [ABSTRACT FROM AUTHOR]
RESEARCH institutes, ORGANIC chemistry, ANNIVERSARIES, SCIENTISTS, and HETEROCYCLIC chemistry
Reports that the N. D. Zelinsky Institute of Organic Chemistry (IOC), a large scientific center in Russia in the field of organic chemistry, organic catalysis, and the chemistry of natural and biologically active compounds, has turned 70 years old on February 23, 2004. Institute's concentration of highly qualified scientists on its staff; Major scientific results achieved by several institute; Studies in heterocyclic chemistry.
Published data and the results of the authors' investigations on the electrochemical conversion of carbon, sulfur, and nitrogen oxides and freons into valuable organic products are reviewed. Considerable attention is paid to the probable mechanisms of such processes, the role and position of the radical-ions and free radicals in them, and the effect of the structure of the reagents, the electrolysis conditions, and other factors on the composition and yield of the products. The problems of developing this promising process, which lies at the junction between physical chemistry, organic chemistry, and ecology, are explored. [ABSTRACT FROM AUTHOR]
RADIOCHEMISTRY, RADIOACTIVE substances, NUCLEAR engineering, NUCLEAR science, and CHEMISTRY education
Given the mismatch between supply of and demand for nuclear scientists, education in nuclear and radiochemistry has become a serious concern. The Nuclear and Radiochemistry in Chemistry Education (NRIChEd) Curriculum Project was undertaken to reintroduce the topics normally covered in a one-semester radiochemistry course into the traditional courses of a four-year chemistry major: general chemistry, organic chemistry, quantitative and instrumental analysis, and physical chemistry. NRIChEd uses a three-pronged approach that incorporates radiochemistry topics when related topics in the basic courses are covered, presents special topics of general interest as a vehicle for teaching nuclear and radiochemistry alongside traditional chemistry, and incorporates the use of non-licensed amounts of radioactive substances in demonstrations and student laboratory experiments. This approach seeks not only to reestablish nuclear science in the chemistry curriculum, but to use it as a tool for elucidating fundamental and applied aspects of chemistry as well. Moreover, because of its relevance in many academic areas, nuclear science enriches the chemistry curriculum by encouraging interdisciplinary thinking and problem solving. [ABSTRACT FROM AUTHOR]
SEDIMENTATION & deposition research, OCEAN bottom, and CARBONATE minerals
Discusses the mechanism underlying the relative deposition rates of organic carbon and calcite to the sea floor. Effect of total calcite concentration on the specific depth at which calcite dissolves; Control of atmospheric carbon dioxide by ocean carbonate chemistry; Organic carbon degradation in the sediments.