Recovery of fluorocarbons in Japan as a measure for abating global warming

The objective of this study is to evaluate the potential for recovering fluorocarbons as measures for the abatement of global warming. In this study, we focused on the three different kinds of fluorocarbons: CFCs, HCFCs and HFCs, and targeted refrigerant use because of the availability of relevant data. We first estimated future fluorocarbon emissions from the targeted appliances; we next compared those emissions in the units of CO₂ equivalent to the level of CO₂ emissions in 1990 from a quantitative point of view. As the result of this study, it was found that fluorocarbon emissions in 1999 and 2010 would be equal to approximately 7 and 3% of the level of CO₂ emissions in 1990 respectively. Moreover, if we implement a 100% recovery rate in every recovery route, we can reduce a large amount of emissions which correspond to approximately 2–5% of the level of CO₂ emissions in 1990, even if we take into account the energy-related CO₂ emissions by the transportation and decomposition of fluorocarbons.     

10 Gbit/s optical BPSK homodyne detection experiment with solitaryDFB laser diodes

Solitary DFB laser diodes with 174 kHz beat linewidth are applied to a 10 Gbit/s optical BPSK homodyne detection system for the first time: a sensitivity of -38.9 dBm was achieved. A three-electrode laser forms the local oscillator and is modulated with a partial push-pull scheme to improve its frequency response     

Isothermal crystallization behavior of hybrid biocomposite consisting of regenerated cellulose fiber,clay, and poly(lactic acid)

Quantitative analysis of isothermal crystallization kinetics of PLA/clay nanocomposite and PLA/clay/regenerated cellulose fiber (RCF) hybrid composite has been conducted. The crystallization rate constant (k) according to Avrami equation was higher in PLA/clay nanocomposite than in PLA/clay/RCF hybrid composite at the same crystallization temperature. The equilibrium melting temperature obtained by Hoffman–Weeks equation was almost same in both composites, whereas stability parameter was greater in hybrid composite than in nanocomposite. Activation energy of hybrid composite for crystallization was larger than that of nanocomposite. The value of nucleation parameter (K_g) and surface free energy (s_e) of hybrid composite were larger than nanocomposite, indicating that hybrid composite has a less folding regularity than nanocomposite. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of buried structure on polarization sensitivity instrained bulk semiconductor optical amplifiers

In order to achieve an accurate design of polarization-insensitive semiconductor optical amplifiers based on tensile strained bulk InGaAsP, the reduction of strain in the active layer of the buried heterostructure and its influence on polarization sensitivity are analyzed numerically for the first time. The gain calculation, including the strain distribution in the active layer, is examined based on the k · p method for the different active layers. It is found that the strain introduced during the epitaxial growth is strongly reduced after regrowth of the burying layer. In an active layer having the aspect ratio of 1 : 4, the strain reduction causes more than a 0.5-dB deviation in the polarization sensitivity of the gain. From a comparison with the experimental results, it is shown that including the effect of the burying layer in the calculation gives an accurate determination of the amount of strain for the polarization independence     

Polymerization of methyl methacrylate by tri-n-butylborane in the presence of amino acid esters

The polymerization of methyl methacrylate by tri-n-butylborane in the presence of amino acid esters was investigated. The binary systems of tri-n-butylborane and amino esters were found to be more effective for initiating the polymerization than tri-n-butylborane alone. Co-catalytic effects of amino acid esters were in the order: tyrosinate > glutamate > aspartate ? phenyl alaninate > serinate > glycinate. The rate of polymerization in a mixture of dimethylsulphoxide and toluene was proportional to the square root of the concentration of the initiator system, to the monomer concentration, and to the concentration of dimethylsulphoxide in the solvent. The overall energy of activation was estimated to be 4.6 kcal/mol for the tri-n-butylborane/methyl tyrosinate system. Copolymerization curves gave a typical free-radical character.     

计算机视觉在球类机器人和行为理解研究中的应用与发展

智能机器人是当今机器人研究的热点，并逐渐由制造领域向非制造领域发展。本文以几种国内外近年研制的新型球类运动机器人为例，介绍了计算机视觉在智能机器人研究中的应用情况。另外，有关人与机器人之间的视觉行为理解研究是计算机视觉研究与智能机器人研究领域的新发展，本文对此也进行了介绍。     

High performance films of cellulose butyral derivative having a necklace-like annular structure in the side chains

We fabricated high performance films using cellulose butyral (CB) synthesized from native cellulose. Two-step reactions were adopted to produce the derivative CB, including etherification of cellulose with glycidol in NaOH/urea aqueous solution to yield O-(2,3-dihydroxypropyl) cellulose (DHPC), and butyralization of DHPC. Both DHPC and CB products were easily processed into a thin film by hot-press molding. The butyral modifier significantly improved the tenacity of highly ductile DHPC, by virtue of the possible chain-entangling action of the ring structures in the stretching process. Thereby the film toughness was markedly enhanced. The CB films exhibited excellent optical transparency and a good adhesive property to glass plates. Thus the films may be comparable to commercial poly(vinyl butyral) (PVB) films in optical and mechanical performances and therefore possess a potential applicability as interlayer for laminated glasses.     

Fabrication of elastic composite hydrogels using surface‐modified cellulose nanofiber as a multifunctional crosslinker

We fabricate composite hydrogels using surface‐modified cellulose nanofiber (CNF) and N‐isopropylacrylamide (NIPAm) as a multifunctional crosslinker and monomer, respectively. We expect to produce unique network structures that lead to elastomeric properties rarely reported for CNF‐based materials. The modification of CNF is performed to introduce polymerizable vinyl groups onto the surface of CNF via condensation between the surface hydroxyl groups and 3‐(trimethoxysilyl)propylmethacrylate. The modification and morphology of the surface‐modified CNF (mCNF) are confirmed by FTIR, solid‐state NMR, and FE‐SEM, respectively. We conduct in situ radical polymerization under various conditions using mixtures of the mCNF aqueous suspension, NIPAm monomer, radical initiator, and catalyst. The mechanical properties of the obtained hydrogels (water content = 90 wt %) are evaluated. The gels can be elastically stretched to more than 700 times their original lengths and exhibit an apparent shape recovery with a small permanent deformation (～1/5 of the applied deformation under the gravity field). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42906.     

Kinetic parameters of the electrode reaction of chloropenta-amminecobalt(III) ions at a gold electrode

The cathodic reduction of chloropenta-amminecobalt(III) ions at active gold electrodes has been studied in 0.1 M HClO₄ + 0.1 M NaClO₄ by means of the potentiostatic method. Chloropentaamminecobalt(III) ions gave one irreversible reduction wave in the double layer potential region of gold electrodes. The kinetic parameters of the electrode reaction were measured at 5, 15, 25, 35 and 45°C, and the activation energy was calculated to be 19 kcal mol^?1 for the electron transfer process and 4.5 kcal mol^?1 for the diffusion process.     

Effects of low-dose cadmium exposure on biological examinations

We conducted an epidemiological study to investigate the effects of low-dose cadmium (Cd) exposure on human health in a specific area of a town in Japan where low Cd concentration was detected in rice. We compared clinical findings, urinary and whole blood Cd concentrations, and indicators of renal dysfunction between the polluted area and the control area. The study employed 44 men and 54 women from the polluted area and 21 men and 29 women from the control area. In urine analysis, as indicators of Cd exposure and possible related renal dysfunction, Cd, beta(2)-microglobulin (beta(2)-MG), alpha(1)-microglobulin (alpha(1)-MG), N-acetyl-beta-D-glucosaminidase (NAG), total protein, inorganic phosphorus, lysozyme and creatinine were quantitatively measured. In blood analysis, serum IP and creatinine and whole blood Cd were measured. No case of renal dysfunction due to Cd exposure was confirmed. However, both the urinary and whole blood Cd of the polluted area were significantly higher than those of the control area for both sexes. Urinary beta(2)-MG did not differ between the two areas. For women, urinary alpha(1)-MG was significantly higher in the polluted area than in the control area. In correlation analysis, beta(2)-MG, alpha(1)-MG and NAG, were positively correlated with both of urinary and whole blood Cd for men and women in the polluted area except for between urinary beta(2)-MG and urinary Cd for men. In the control area, the sole positive correlation observed was between urinary beta(2)-MG and whole blood Cd for men. We then examined the determinants of variations of parameters in urinary and blood tests. Potential determinants were age, sex, body mass index, an indicator of smoking habits (cigarette index) and the index of estimated Cd intake from rice (Cd-rice-index). Cd-rice-index was expressed as the product of Cd concentrations in homegrown rice multiplied by daily frequency multiplied by duration (years) of residence in the polluted area. In multiple regression analysis, whole blood Cd was independently associated with Cd-rice-index, age and gender. Variations in whole blood Cd accounted for a substantial portion of the variations in urinary Cd, although they were less influential in older individuals. Whole blood Cd was the sole independent variable related to variations in urinary beta(2)-MG. Cd-rice-index accounted for a portion of the variance in urinary NAG, while age was a more powerful determinant. It was thus revealed that the consumption of homegrown rice polluted with Cd in low concentration resulted in an elevation of whole blood Cd level and consequent increase in urinary Cd level. However, it was not clearly elucidated that the excretion of urinary low-molecular microglobulins could increase significantly in response to slight elevation of Cd body load.