Reaction between magnesium ammine complex compound and lithium hydride

The possibility of using ammonia as a hydrogen carrier is examined for the reaction between magnesium ammine complex MgCl₂(NH₃)₆ and lithium hydride LiH. Sample was milled at low temperature of −40 °C to avoid decomposition of MgCl₂(NH₃)₆ during the milling. The effects of milling time, milling speed (revolutions per minute), and catalysts on hydrogen storage properties were investigated by thermogravimetry, thermal desorption mass spectroscopy, and X-ray diffraction experiments. Experimental results indicated that a milled composite of Mg(NH₃)₆Cl₂ and catalyzed-LiH desorbed the ∼100% H₂ gas even at 125 °C in a closed system. The reverse reaction also proceeded by separately cooling MgCl₂ at lower temperature than 100 °C and heating LiNH₂ at 300 °C in the closed system.     

Effects of annual fluctuation of environmental factors on starch properties in potato tuber development

To test the effects of the annual fluctuation of the environmental factors on the starch properties in potato tuber development, starches were isolated from potato cultivars grown for ten consecutive years (2001–2010) on the experimental farm in Memuro, Hokkaido, the northernmost island of Japan. The median granule size, phosphorus content, and rapid visco‐analyzer pasting properties, peak viscosity, breakdown, and pasting temperature of these starches were analyzed. Daily temperature and precipitation records in Memuro were obtained from the Japan Meteorological Agency. Moreover, the correlation coefficients of yearly accumulated temperature and precipitation from flowering to harvesting with all the starch quality parameters were calculated. No relationships of accumulated temperature with median granule size, peak viscosity, and breakdown were found. The low phosphorus content was slightly associated with the high accumulated temperature. The pasting temperature was significantly and positively correlated with the accumulated temperature, suggesting that the pasting temperature strongly responds to the environmental temperature during potato tuber development. In contrast, all the starch quality parameters were almost irrespective of the precipitation during potato tuber development.     

The Atmospheric Scanning Electron Microscope with open sample space observes dynamic phenomena in liquid or gas

Although conventional electron microscopy (EM) requires samples to be in vacuum, most chemical and physical reactions occur in liquid or gas. The Atmospheric Scanning Electron Microscope (ASEM) can observe dynamic phenomena in liquid or gas under atmospheric pressure in real time. An electron-permeable window made of pressure-resistant 100 nm-thick silicon nitride (SiN) film, set into the bottom of the open ASEM sample dish, allows an electron beam to be projected from underneath the sample. A detector positioned below captures backscattered electrons. Using the ASEM, we observed the radiation-induced self-organization process of particles, as well as phenomena accompanying volume change, including evaporation-induced crystallization. Using the electrochemical ASEM dish, we observed tree-like electrochemical depositions on the cathode. In silver nitrate solution, we observed silver depositions near the cathode forming incidental internal voids. The heated ASEM dish allowed observation of patterns of contrast in melting and solidifying solder. Finally, to demonstrate its applicability for monitoring and control of industrial processes, silver paste and solder paste were examined at high throughput. High resolution, imaging speed, flexibility, adaptability, and ease of use facilitate the observation of previously difficult-to-image phenomena, and make the ASEM applicable to various fields.     

Alginate‐coated chitosan membrane for guided tissue regeneration

Chitosan membranes were first prepared by a thermally induced phase separation method and then alginate was coated on one side of the membranes by a modified dialysis apparatus to prepare alginate/chitosan membranes (A/C membranes). Electron spectroscopy for chemical analysis (ESCA), scanning electron microscope, and contact angle measurements were conducted to evaluate the surface characteristics. The mechanical strength, degradation behavior, and cell adhesion test were performed to evaluate the feasibility of using A/C membrane in guided tissue regeneration applications. The results revealed that alginates could effectively be coated onto the chitosan membrane. As observed in ESCA results, the N‐atomic emission peak was decreased from originally 6.2% on the untreated chitosan surface to 2% on the alginate‐treated surface. The contact angle decreased on the alginate‐modified side substantially, compared with the untreated side (from 88.4° to 34.2°). The A/C membrane had a higher water content of 71.8% in comparison to the chitosan membrane of 61.8%. Consequently, A/C membrane became stiffer and had a higher Young's modulus and strength. After a 30‐day in vitro shaking test, the weight of membranes was degraded to about 75% from the original. The 3T3 fibroblast cells showed less adhesion to alginate‐modified side as compared to the untreated chitosan‐side in cell adhesion test. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4528–4534, 2006     

Fully automated two-dimensional electrophoresis system for high-throughput protein analysis

We developed a fully automated electrophoresis system for rapid and highly reproducible protein analysis. All the two-dimensional (2D) electrophoresis procedures including isoelectric focusing (IEF), on-part protein staining, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and in situ protein detection were automatically completed. The system comprised Peltiert devices, high-voltage generating devices, electrodes, and three disposable polymethylmethacrylate (PMMA) parts for IEF, reaction chambers, and SDS-PAGE. Because of miniaturization of the IEF part, rapid IEF was achieved in 30 min. A gel with a tapered edge gel on the SDS-PAGE part realized a connection between the parts without use of a gluing material. A biaxial conveyer was employed for the part relocation, sample introduction, and washing processes to realize a low-maintenance and cost-effective automation system. Performances of the system and a commercial minigel system were compared in terms of detected number, resolution, and reproducibility of the protein spots. The system achieved high-resolution comparable to the minigel system despite shorter focusing time and smaller part dimensions. The resulting reproducibility was better or comparable to the performance of the minigel system. Complete 2D separation was achieved within 1.5 h. The system is practical, portable, and has automation capabilities.     

High prevalence of voiding symptoms in Taiwanese women

Selenium is a trace element which plays a vital role in many metabolic functions and in particular is an integral part of the antioxidant enzyme glutathione peroxidase. It may be involved in the prevention of a number of diseases including cardiovascular diseases and cancer, which are the main causes of death in Singapore with ethnic differences. The National University of Singapore Heart Study measured cardiovascular risk factors, including serum selenium, in a random of the general population aged 30 to 69 years from 1993 to 1995. Mean serum selenium was higher in Chinese (males 126 and females 119 micrograms/L) and Malays (males 122 and females 122 micrograms/L) than Indians (males 117 and females 115 micrograms/L). These levels (with an estimated mean of 122 micrograms/L in Singapore) are lower than those in the USA but higher than those in Western Europe. The proportions with serum selenium < 80 micrograms/L (classified as low values) were low, though highest in Indians (males 1.2% and females 1.2%), then Chinese (males 0.6% and females 1.3%) and then Malays (males 0.0% and females 0.0%), but the differences were not statistically significant. The overall estimate for the prevalence of low selenium in Singapore was 0.8%. It is concluded that levels of serum selenium in Singapore are satisfactory and no action with regard to dietary supplementation is needed. Serum selenium levels are slightly lower in Indians than in Chinese and Malays (probably due to a more vegetarian diet) and this may make a small contribution to Indians' higher rates of coronary heart disease compared to Chinese and Malays.     

Plasma copolymer membranes of acrylic acid and the adsorption of lysozyme on the surface

Plasma copolymerization was carried out from the monomer mixtures of acrylic acid with hexamethylxdisilozane and hexametydisillazane, and the membranes composed of the Si-C and/or Si-O networks sustaining carboxylic acid group were fabricated. The carboxylic acid contents were dependent on the discharge power conditions as well as the monomer ratio, and carboxylic acid was introduced at the more density in the polymerization by plasmas under the moderate power conditions. The plasma polymer coatings were effective for the adsorption of lysozyme especially on the plasma copolymer films of acrylic acid.     

Evaluation of additive effects and homogeneity of the starting mixture on the nuclei-growth processes of barium titanate via a solid state route

In an attempt to obtain finest possible microparticles of BaTiO₃ (BT) with highest possible tetragonality via a solid state route, starting mixtures comprising BaCO₃ and TiO₂ were subjected to various pretreatments including addition of glycine and mechanical activation. Reaction processes were monitored by the changes in the weight, crystallinity, and morphology in detail. While mechanical activation with glycine significantly increased the rate of reaction and homogeneity of the particle size of the product, BT, simultaneous particle growth of BT was intolerably acute for micro-electronic devices. The fast particle coarsening was predominated by the coalescence of BT tiny particles formed around titania. A mixture with higher homogeneity was attained by using finer starting materials under wet mixing, avoiding significant mechanical stressing. Particle growth of BT was suppressed to ca. 100 nm to obtain fully crystallized BT particles without significant loss of tetragonality and, hence, close to meet our requirements for MLCCs.     

Preparation of one-dimensional photonic crystals by sol-gel process for magneto-optical materials

One-dimensional photonic crystal (PC) of periodically alternating low (SiO₂) and high (TiO₂) refractive index materials was prepared by sol-gel dip coating method that controls the thickness of each layer with nanometer level. The photonic band gap of high reflectivity was verified at wavelengths between 590 nm and 820 nm, which became significant with increasing the number of bilayer. The UV-vis spectra, SEM image and glow discharge optical emission spectroscopy indicate the periodic structure of SiO₂/TiO₂ multilayer. The magnetic layer of CoFe₂O₄ was also prepared by a sol-gel dip coating method. After the annealing at 700 °C, the single phase of CoFe₂O₄ film with spinel structure, without any preferred crystalline orientation, was obtained. In addition, the one-dimensional magnetophotonic crystal (MPC), in which the magnetic defect layer of CoFe₂O₄ is introduced into the periodic structure, was prepared. The light was localized at the magnetic defect due to the interference of the multilayer film, and the localized transmittance was observed around 530 nm. The Faraday rotation of MPC shows a peak at ∼ 570 nm which is close to the localized peak of transmittance. This may correspond to the enhancement of Faraday rotation due to the localization of light.     

Numerical studies on constrained venting system with reactive mufflers by GA optimization

While the space volume of mufflers in a venting system gets constrained, shape optimization to maximize the muffler's performance becomes important and essential. This paper presents a genetic algorithm (GA) for the optimal shape design of mufflers. The four‐pole matrix method which was adopted in evaluating the acoustic performance of sound transmission loss (STL) is used in conjunction with the GA techniques. Case studies of the full band noise inside a venting system are exemplified by the reactive mufflers. Before the GA operation, several examples are tested and compared with the experimental data for accuracy check of the mathematical models. Consequently, GA can provide a quick and effective way for a muffler design work. Copyright © 2005 John Wiley & Sons, Ltd.