Dow Chemical (Japan)

Recent reviews by researchers from academia, industry, and government have revealed that the criteria used by the Stockholm Convention on persistent organic pollutants under the United Nations Environment Programme are not always able to identify the actual bioaccumulative capacity of some substances, by use of chemical properties such as the octanol-water partitioning coefficient. Trophic magnification factors (TMFs) were suggested as a more reliable tool for bioaccumulation assessment of chemicals that have been in commerce long enough to be quantitatively measured in environmental samples. TMFs are increasingly used to quantify biomagnification and represent the average diet-to-consumer transfer of a chemical through food webs. They differ from biomagnification factors, which apply to individual species and can be highly variable between predator-prey combinations. The TMF is calculated from the slope of a regression between the chemical concentration and trophic level of organisms in the food web. The trophic level can be determined from stable N isotope ratios (δ(15) N). In this article, we give the background for the development of TMFs, identify and discuss impacts of ecosystem and ecological variables on their values, and discuss challenges and uncertainties associated with contaminant measurements and the use of δ(15) N for trophic level estimations. Recommendations are provided for experimental design, data treatment, and statistical analyses, including advice for users on reporting and interpreting TMF data. Interspecies intrinsic ecological and organismal properties such as thermoregulation, reproductive status, migration, and age, particularly among species at higher trophic levels with high contaminant concentrations, can influence the TMF (i.e., regression slope). Following recommendations herein for study design, empirical TMFs are likely to be useful for understanding the food web biomagnification potential of chemicals, where the target is to definitively identify if chemicals biomagnify (i.e., TMF > or < 1). TMFs may be less useful in species- and site-specific risk assessments, where the goal is to predict absolute contaminant concentrations in organisms in relation to threshold levels.

Histopathology is the study of the structural manifestations of disease at the light-microscopic level. The microscopic examination of a tissue specimen is an evaluation of a 2-dimensional image of a complex 3-dimensional

BACKGROUND: The commercialization of new insecticides is important for ensuring that multiple effective product choices are available. In particular, new insecticides that exhibit high potency and lack insecticidal cross-resistance are particularly useful in insecticide resistance management (IRM) programs. Sulfoxaflor possesses these characteristics and is the first compound under development from the novel sulfoxamine class of insecticides. RESULTS: In the laboratory, sulfoxaflor demonstrated high levels of insecticidal potency against a broad range of sap-feeding insect species. The potency of sulfoxaflor was comparable with that of commercial products, including neonicotinoids, for the control of a wide range of aphids, whiteflies (Homoptera) and true bugs (Heteroptera). Sulfoxaflor performed equally well in the laboratory against both insecticide-susceptible and insecticide-resistant populations of sweetpotato whitefly, Bemisia tabaci Gennadius, and brown planthopper, Nilaparvata lugens (Stål), including populations resistant to the neonicotinoid insecticide imidacloprid. These laboratory efficacy trends were confirmed in field trials from multiple geographies and crops, and in populations of insects with histories of repeated exposure to insecticides. In particular, a sulfoxaflor use rate of 25 g ha(-1) against cotton aphid (Aphis gossypii Glover) outperformed acetamiprid (25 g ha(-1) ) and dicrotophos (560 g ha(-1) ). Sulfoxaflor (50 g ha(-1) ) provided a control of sweetpotato whitefly equivalent to that of acetamiprid (75 g ha(-1) ) and imidacloprid (50 g ha(-1) ) and better than that of thiamethoxam (50 g ha(-1) ). CONCLUSION: The novel chemistry of sulfoxaflor, its unique biological spectrum of activity and its lack of cross-resistance highlight the potential of sulfoxaflor as an important new tool for the control of sap-feeding insect pests.

A blend of phenyl-substituted, branched polysilane, (Ph(2)Si)(0.85)(PhSi)(0.15), and polystyrene (1:1 in weight) has been transformed into a composite material consisting of graphene layers, Si-O-C glasses, and micropores through a pyrolytic polymer-to-ceramic conversion. Several analytical techniques have been employed to characterize the Si-O-C composite material, demonstrating the presence of the three components in its host framework. The Si-O-C composite material performs well in electrochemical operations with a characteristic voltage plateau, offering a capacity of more than 600 mA h g(-1). When polystyrene is not blended, the resulting comparative material is even less porous and shows a shorter voltage plateau in electrochemical operations. A broad resonance in the (7)Li NMR spectrum recorded at low temperature can be deconvoluted into three components in the fully lithiated state of the Si-O-C composite material derived from the polymer blend. This result indicates that the Si-O-C composite material electrochemically stores lithium species in interstitial spaces or edges of the graphene layers, directly or indirectly the Si-O-C glass phase, and the micropores. However, both the Si-O-C glass phase and micropores are minor as electrochemically active sites for lithium storage, and interstitial spaces or edges of the graphene layers act as major electrochemically active sites in this composite material. Despite the excellent cyclability of the Si-O-C composite material, the voltage plateau disappeared over cycling. This phenomenon suggests that the microstructure is delicate for repetitive lithium insertion and extraction and that newly formed sites must generate the nearly equal capacity.

This chapter contains sections titled: Introduction Elements of Thermodynamics in DSC The Basics of Differential Scanning Calorimetry Purity Determination of Low-Molecular-Mass Compounds by DSC Calibration of Differential Scanning Calorimeters Measurement of Heat Capacity Phase Transitions in Amorphous and Crystalline Polymers Fibers Films Thermosets Differential Photocalorimetry (DPC) Fast-Scan DSC Modulated Temperature Differential Scanning Calorimetry (MTDSC) How to Perform DSC Measurements Instrumentation Appendix Abbreviations References

More than sixty siloxane polymers containing various organofunctional siloxane units were synthesized. The synthesized siloxane polymers were pyrolyzed in inert gas at 1000°C. Chemical analysis showed that the products of pyrolysis were distributed over a well‐defined region in the Si‐C‐O Gibbs phase diagram. The electrochemical and structural properties of these materials were measured using coin‐type test cells and x‐ray powder diffraction, respectively. The most interesting materials are found near the line in the Si‐C‐O Gibbs triangle connecting carbon to . Materials with the largest reversible specific capacity for lithium (about 900 mAh/g) are on this line and were at about 43% carbon, 32% oxygen, and 25% silicon (atomic percent). Materials which were almost pure carbon showed diffraction patterns characteristic of disordered carbons. Along the line from carbon to the sample structure can be described as a mixture of single or small groups of graphene sheets mixed with regions of Si‐C‐O amorphous glass. The amount and composition of the glass changed according to the overall sample composition. Moving from carbon to , the reversible capacity first rises from about 340 mAh/g for pure carbon, to a maximum of 900 mAh/g near 50% carbon, and then falls to near zero mAh/g at 0% carbon. This suggests that the amorphous glass can reversibly react with lithium, provided the carbon is present to provide a path for electrons and Li ions. However, the hysteresis in the voltage profile (difference between charge and discharge voltages) and the irreversible capacity increase almost linearly along this line. There is a clear correlation between both the irreversible capacity and hysteresis in these materials with their oxygen content. Along the line connecting carbon to silicon, the reversible capacity rises from 340 mAh/g for pure carbon to about 600 mAh/g for samples with about 15 atomic percent Si. It then decreases to near zero as the composition nears SiC. Along the C‐SiC line, the irreversible capacities remain below about 200 mAh/g. We are quite convinced that optimized silicon‐containing carbons can be good alternatives to pure carbons as anode materials in lithium‐ion batteries.

We report the effect of processing variables on the inversion layer electron mobility of (0001)-oriented 4H-SiC n-channel MOSFETs. The process variables investigated include: i) implant anneal temperature and ambient; ii) oxidation procedure; iii) postoxidation annealing in nitric oxide (NO); iv) type of gate material, and v) high-temperature ohmic contact anneal. Electron mobility is significantly increased by a postoxidation anneal in NO, but other process variations investigated have only minor effects on the channel mobility. We also report the temperature dependence of electron mobility for NO and non-NO annealed n-channel MOSFETs.

There is increasing international interest in recovery approaches in mental health—and this connects with an emerging focus within European social work around promoting capability and sustainability. Research at a population level would suggest that social factors rather than medical interventions are the main determinants of recovery from mental health difficulties—but this is not yet reflected in social work practice, which can still be dominated by biomedical perspectives and a focus on risk management. Drawing upon and extending analyses of social and other forms of capital, this paper outlines the basis for a new paradigm for mental health social work that is specifically oriented towards enabling the development of personal efficacy and social capability—an approach that is explicitly focused on achieving longer-term sustainability rather than shorter-term problem solving.

The partial coalescence of a droplet onto a planar liquid-liquid interface is investigated experimentally by tuning the viscosities of both liquids. The problem mainly depends on four dimensionless parameters: The Bond number (gravity vs surface tension), the Ohnesorge numbers (viscosity in both fluids vs surface tension), and the density relative difference. The ratio between the daughter droplet size and the mother droplet size is investigated as a function of these dimensionless numbers. Global quantities such as the available surface energy of the droplet have been measured during the coalescence. The capillary waves propagation and damping are studied in detail. The relation between these waves and the partial coalescence is discussed. Additional viscous mechanisms are proposed in order to explain the asymmetric role played by both viscosities.

The purpose of these experiments was to determine the potential estrogenic, androgenic, and progestagenic activity of two cyclic siloxanes, octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). Receptor-binding experiments and a luciferase reporter gene assay were used to determine if the materials were able to bind and activate either the estrogen receptors (ERs) or progesterone receptors (PRs)-alpha or beta. The rat uterotrophic assay (RUA) for estrogenic activity and the Hershberger assay for androgenic activity were utilized as the in vivo assays. For the ER-binding studies, D4 was shown to bind to ERalpha but not to ERbeta. D5 did not bind to either of the two receptors. D4 activated the reporter gene at 10 microM, while D5 was considered negative in the estrogen reporter gene assay. Neither material was a ligand for the PRs. Both the RUA and Hershberger assays were conducted using whole-body inhalation of the two materials for 16 h/day. D4 resulted in a small but significant increase in both wet and blotted uterine weight as well as increases in both luminal and glandular epithelial cell height in both Sprague Dawley and Fischer 344 rats. D5 was negative in both rat strains, indicating that D5 does not possess estrogenic activity. Neither material possessed any significant antiestrogenic activity. Both materials were negative in the Hershberger assay indicating that neither material possesses any significant androgenic activity. Our studies have shown that D4 exhibits a low affinity for ERalpha in vitro and a weakly estrogenic response in vivo.

Abstract Like carbenes, silylenes are assumed to occur as intermediates in many reactions. A detailed account of the reactivity of the silylenes is given and the reductive and thermolytic methods used for their preparation are discussed. Insertion and interception reactions emphasize the formal relationship between these species and the carbenes. Silacyclopropenes and silacyclopropanes have not, as yet, been isolated.

Journal Article Variation in Natural Abundance of 15N among Plant Parts and in 15N/14N Fractionation during N2 Fixation in the Legume-Rhizobia Symbiotic System Get access Tadakatsu Yoneyama, Tadakatsu Yoneyama 1Department of Applied Physiology, National Institute of Agrobiological ResourcesKannondai, Tsukuba, Ibaraki 305, Japan Search for other works by this author on: Oxford Academic Google Scholar Kounosuke Fujita, Kounosuke Fujita 2Faculty of Applied Biological Science, Hiroshima UniversityFukuyama, Hiroshima 720, Japan Search for other works by this author on: Oxford Academic Google Scholar Tomio Yoshida, Tomio Yoshida 3Institute of Applied Biochemistry, University of TsukubaSakura-mura, Niihari, Ibaraki 305, Japan Search for other works by this author on: Oxford Academic Google Scholar Tetsuo Matsumoto, Tetsuo Matsumoto 4Dow Chemical Japan Limited92-2 Ogurano, Gotemba, Shizuoka 412, Japan Search for other works by this author on: Oxford Academic Google Scholar Iwao Kambayashi, Iwao Kambayashi 5Department of Agricultural Chemistry, Nihon UniversitySetagaya-ku, Tokyo 154, Japan Search for other works by this author on: Oxford Academic Google Scholar Jinya Yazaki Jinya Yazaki 5Department of Agricultural Chemistry, Nihon UniversitySetagaya-ku, Tokyo 154, Japan Search for other works by this author on: Oxford Academic Google Scholar Plant and Cell Physiology, Volume 27, Issue 5, July 1986, Pages 791–799, https://doi.org/10.1093/oxfordjournals.pcp.a077165 Published: 01 July 1986 Article history Received: 08 October 1985 Accepted: 07 April 1986 Published: 01 July 1986

Abstract The medical grade silicones are probably the most widely used of all the synthetic polymers for permanently implanted subdermal devices. This paper reviews the chemistry of these materials from the original polymer manufacturing through the various stages necessary to obtain the types of heat vulcanizing silicone rubber, room temperature vulcanizing silicone rubber, and silicone rubber adhesive most commonly used in medical applications.

Abstract The aqueous solubility of several low mlecular weight linear, cyclic, and branched permethylsiloxanes was determined at room temperature. A method for preparing molecularly dispersed, colloid-free saturated aqueous solutions is described. Solubilities, decreasing with increased molecular weights, ranged downward from one part per million to mere parts per trillion. The cyclic oligomers were slightly more soluble than their linear analogues. While the effect of branching was mixed, polar groups such as phenyl and hydroxyl moities sharply increased aqueous solubility. Semilog plots of the solubility/molecular weight yielded linear regressions, the extrapolation of which indicate the absence of any environmentally relevant water solubility (&amp;lt; 1 ppt) for the conventional higher molecular weight polydimethylsiloxanes of commerce.

We examine the link between public opinion and policy in the UK over the past 30 years. We show that public views about immigration are responsive to changes in immigration levels and differences between migrant groups, and that policy-makers are sensitive to these changes. Policy-makers look to respond to the public mood on migration, but face growing constraints in doing so. The interaction of public opinion, policy and constraint has produced three distinct policy regimes. In the first, from 1982 to 1997, policy-makers faced few constraints, immigration was tightly controlled and the public were unconcerned about the issue. In the second, from 1997 to 2004, migration policy was selectively liberalised in response to external and interest group pressures, producing increasing inflows and growing public demands for restriction. In the third, from 2004 to the time of writing, public demand for restriction is strong but policy-makers face significant constraints in responding. In all periods, policy-makers seek to focus restriction on the migrant streams most opposed by the public, but as they have lost discretionary power over the issue they have been forced to take action against more economically valuable and socially accepted migrant streams. The growing constraints on policy-makers have therefore sharpened the trade-off between the ‘responsive’ government of meeting public demands for immigrations restriction and the ‘responsible’ government goal of providing for the needs of a flexible, globally integrated economy.

Hydrophobic polysiloxane-like thin films have been deposited onto polyethylene by introducing octamethylcyclotetrasiloxane and tetramethylcyclotetrasiloxane precursors through an ultrasonic atomizer into an atmospheric pressure glow discharge. Enrichment of the gas feed with oxygen gives rise to the formation of hydrophilic SiOx coatings which exhibit an improvement in gas barrier.

Abstract Selectivity coefficients for Pb 2+ , Cd 2+ , and Ca 2+ exchange adsorption with montmorillonite, illite, and kaolinite clays were determined over a wide range of clay surface concentration and found constant. The average selectivity coefficients describing the ion distributions for montmorillonite, illite, and kaolinite, respectively, were 0.60, 0.44, 0.34 for Pb‐Ca exchange, 1.04, 1.01, 0.89 for Cd‐Ca exchange and 0.58, 0.56, 0.31 for Pb‐Cd exchange. Whereas Cd 2+ may compete more or less on an even basis with Ca 2+ for clay adsorption sites, the adsorption of Pb 2+ would be favored by a factor of 2 or 3 over Ca 2+ .

We report on the implementation of novel flexible polymer waveguide interconnects. They are based on newly developed mechanically flexible low-loss silicone waveguides. In addition to meeting the generic requirements of rigid waveguide interconnects, several flex-material challenges were mastered: a) mechanical flexibility permitting waveguide flexing down to radii of 1.0 mm without cracking; b) minimization of waveguide curling induced by the CTE mismatch between flex substrates and polymer layers to enable assembly and connectorization; c) greatly improved cladding adhesion on standard PCB flex substrates, such as polyimide; and d) high environmental stability despite the reduced polymer cross-linking required for better mechanical flexibility. The new waveguides exhibit excellent stability in damp heat (2000 h in 85°C/85% rH) and under thermal shock (500 cycles from -40° to +120°C), and lead-free solder reflow up to 260°C. Using the newly engineered “Dow Corning WG-1017 Optical Waveguide Clad Dev Sample” and the established “Dow Corning WG-1010 Optical Waveguide Core”, we were able to develop a manufacturing process suitable for large areas and offering high process control and stability to produce waveguides having optical loss values of less than 0.05 dB/cm at 850 nm VCSEL wavelength and fulfilling requirements (a) to (d) above. We describe this manufacturing process and how we have overcome the material challenges mentioned. Furthermore, we present characterization and manufacturing results, show demonstrators, and outline the potential of flexible waveguides as versatile electro-optic assembly platform.

The phase behavior of a long hydrophobic chain A−B-type silicone surfactant, Me3SiO−(Me2SiO)m-2−Me2SiCH2CH2CH2−O−(CH2CH2O)nH (Sim C3EOn), in water was investigated by phase study and small-angle X-ray scattering (SAXS). The types of liquid crystals or self-organized structures are highly dependent on both EO-chain (n) and poly(dimethylsiloxane)-chain (m) lengths or the volume ratio of the EO chain to the total surfactant, nVEO/VS, which is related to the classical Griffin's HLB value. Reverse discontinuous cubic phase (I2) for Si14C3EO7.8 and Si25C3EO7.8,12.2,15.8, reverse hexagonal phase (H2) for Si14C3EO12, lamellar (Lα) phase for Si14C3EO15.8 and Si25C3EO51.6, and hexagonal (H1) and discontinuous cubic (I1) phases for Si5.8C3EO36.6,51.6 are formed. Hence, both hydrophobic and hydrophilic chains affect the surfactant layer curvature, but in an opposite way. On the other hand, the effective cross-sectional area per surfactant at the hydrophobic surface of self-organized structures, aS, increases with increasing m (or n) at constant n (or m). aS is related to the amphiphilicity of surfactant (surfactant size). Since the surfactant layer curvature changes from positive to negative with increasing m at constant n, the leff/lmax decreases with m, where leff is the effective hydrophobic-chain length and lmax is the length of the chain in its fully extended form. Namely, the entropy loss of a long hydrophobic chain would be largely increased when it is stretched, and thus, long hydrophobic chain tends to be in a shrunk-bulky state. This causes the expansion of aS and the change in the surfactant layer curvature from positive to negative. In a similar mechanism, aS increases with increasing the EO-chain length, n, but the surfactant layer curvature changes from negative to positive.

This study demonstrates the shielding effects of a silica-ash layer on the combustion of silicones and their possible applications on the fire retardancy of organic materials. The deposited silica-ash layer, formed on the surface of silicone materials during combustion, has shielding effects on the combustion of silicones. It insulates the burning surface from the radiant heat of flame, as well as from the radiant heat produced from the burning of adjacent materials. It also restricts the diffusion of fuels into the combustion zone and the access of oxygen to the unburned fuels. The shielding effects provide some of the fundamentals for the development of silicone-based fire retardants. © 1998 John Wiley & Sons, Ltd.