Enhancement of hydrogen production by a photosynthetic bacterium mutant with reduced pigment

A novel mutant MTP4 was created from the wild-type strain Rhodobacter sphaeroides RV by UV irradiation for the enhancement of hydrogen production. The amount of light absorbed by MTP4 was lower than that by the wild-type strain at any wavelengths ranging from 350 to 1000 nm. This nature enables the illumination of cells in the deeper parts of a reactor. The contents of bacteriochlorophylls and carotenoids of the chromatophores prepared from MTP4 under the conditions for hydrogen production were reduced to 41 and 49% of those from the wild-type strain RV, respectively. Analysis of the light-harvesting (LH) complexes by SDS-PAGE showed that the amounts of LH1s and reaction centers (RCs) in MTP4 were retained, whereas that of LH2s was much less than that in RV. Although MTP4 had less pigments, its growth rate was equivalent to that of RV over a wide range of light intensities. MTP4 produces hydrogen with a stable manner. Using a plate-type reactor, it produced 50% more hydrogen than RV. A novel method of pigment reduction was found to be effective for the enhancement of hydrogen production per unit reactor.     

Competitive interaction of polyanions and anionic dye with bovine serum albumin

The binding of anionic dye, p-(2-amino-6-sulfonyl-8-naphthylazo)benzene sulfonic acid disodium salt (ASANA) to bovine serum albumin (BSA) at pH 7.5 has been studied by spectrophotometric techniques. The values of the dissociation constants were obtained with the use of the Benesi-Hildebrand equation for ASANA. Competitive binding of polyanions, sodium poly(styrene sulfonate) (PSSNa), potassium poly(vinyl sulfonate) (PVSK), poly(acrylic acid) (PAA), and poly(methacrylic acid) (PMAA) and anionic dye to BSA was evaluated through the variations in the different spectra of BSA-dye-polymer systems.     

A new preparative method for cyclohexenyl alkenyl ketones

New cyclohexenyl alkenyl ketones are prepared by the reaction of various methyl cyclohexenyl carboxylates and vinylmagnesium chloride; for example, 1-(4′-methyl-3′-cyclohexene-1′-yl)-1-oxo-4-pentene is obtained from methyl 4-methyl-3-cyclohexene-1-carboxylate and vinylmagnesium chloride.     

Transformations of the wavelength of the light incident upon solar cells

A method for the improvement of the spectral response of solar cells was proposed. The attachment of the fluorescent plate on the CdS/CdTe cells made the cell sensitive to the light at wavelength below 510 nm, transforming the wavelength of the incident light from non-photoresponsive region (below 510 nm) to photoresponsive region (above 510 nm). A simple analytical model for the maximum power of the cell showed that the increase in the maximum power for the irradiation of sunlight (Air Mass 1.5, direct) was 33%. Furthermore, a possible increase amounted to 40%, if the fluorescent quantum efficiency took the value of 1.0 and that the wavelength of the absorbed light was completely shifted above 510 nm where internal quantum efficiency of the solar cell is equal to 1.0.     

A new apparatus for measuring total hemispherical emittance of surfaces at room temperature

Radiation heat transfer is an important mode of heat transfer even in our life space at room temperature. Such radiation heat transfer is evaluated mostly by calculating the radiation energy exchange among surfaces in an enclosure. For this evaluation, knowledge of the hemispherical emittances of the constituent life surfaces is needed. However, there has not been a suitable technique for measuring the emittance of each surface in the life space at room temperature. In the present work we develop a new apparatus for measuring total hemispherical emittances of real surfaces at room temperature. The apparatus consists of a total radiation flux meter and a Peltier element cooler to cool the flux meter surface from the back, and measure the net total radiation flux from the specimen surface to the surrounding surfaces to determine the total hemispherical emittance of the specimen surface. This apparatus is effective to measure total hemispherical emittances of surfaces at room temperature on site. We apply the developed apparatus to measure the total hemispherical emittances of various surfaces in the life space, such as metals, human skin, cloth, floor mat, wood, glass, brick tile, stone, cement, plant leaves, etc., and demonstrate the feasibility of the apparatus. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20349     

Preparation of self-bursting microcapsules by interfacial polymerization

Here, we describe a new technique for microencapsulating pyriproxyfen, a widely used insect growth regulator. Using interfacial polymerization, we successfully prepared self-bursting microcapsules that retained their shape when suspended in water but break open quickly after the water evaporates. In order to investigate the self-bursting phenomenon, we studied the relationship between formulation factors such as volume median diameter (D) or wall thickness (T) and the physical strength of the obtained polyurethane films. As a result, it was found that T and the structure of isocyanate affected the self-bursting phenomenon.     

Transformations of the wavelength of the light incident upon CdS/CdTe solar cells

A method for the improvement of the spectral response of the CdS/CdTe solar cell was proposed. The coatings of fluorescent coloring agent (FCA) on the cell made the cell sensitive to light at wavelengths below 510 nm, transforming the wavelength of the incident light from non-incentive region (below 510 nm) to incentive region (above 510 nm). The FCA coatings showed about 8% and 14% increases in the maximum power of the solar cell under the radiations of a white and day-light fluorescent lamp, respectively. Possible maximum output powers were predicted by using a simple model for the external quantum efficiency of the cell.     

Permeation of solutes in water-swollen poly(vinyl alcohol-co-itaconic acid) membranes

Partition and permeability coefficients of urea, NaCl, and saccharose in water-swollen poly(vinyl alcohol-co-itaconic acid) membranes with various water contents (0.25 ? H ? 0.86) were measured. Partition coefficients and permeability ratios in freezing and nonfreezing water were estimated based on a parallel permeation model. It was suggested that at 25°C the permeation of saccharose in the nonfreezing water was nearly zero due to its negligible partition coefficient, while NaCl and urea were found to be able to permeate even the nonfreezing water. The activation energies of diffusion for three solutes were found to increase with the decrease of water content of the membranes. Since the fraction of nonfreezing water increased with the decrease of water content of the membranes, it is assumed that the increased activation energy of diffusion is due to the fact that the diffusion in nonfreezing water needs higher activation energy than in the pure bulk water.     

Dual excitation electrostatic stepping motor

Electrostatic motors have been believed to be weaker than electromagnetic motors which are typically used for mechatronic devices. However, electrostatic motors are preferable to electromagnetic ones for micromechanical applications since their force per volume ratios increase as their dimensions are reduced. It follows that a large output should be obtained if a large number of such small motors with high force per volume ratios are linked and their outputs are aggregated. This paper proposes an electrostatic drive technology which is applicable to such a large-output motor. The element motor, called the dual excitation electrostatic stepping motor, consists of a pair of plastic films, slider and stator. Both films have parallelly located electrodes embedded in them, and the slider moves along the surface of the stator when defined rectangular pulse voltages are applied to the electrodes both in the slider and the stator. The force generation characteristic of the electrostatic motor is calculated by the surface charge method. A prototype fabricated using flexible print board technology weighs 7 g and generates a thrust force of 1.9 N at an excitation of ± 1000 V. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(3): 94–103 1997     

In Situ Monitoring of Lipid Phase State Make Target Lipid Mixtures Similar to Intercellular Lipid in the Stratum Corneum

In this study, lipid structural change is monitored using Raman spectroscopy during heat treatment, along with the impact of lipid states on the structural and physical properties during the preparation process of the dried and hydrated lipid mixture (LM) similar to intercellular lipid in stratum corneum. The microstructures and thermal behavior of these LMs change depending on the melting of lipid ingredients in the preparation process. It is recognized that variable temperature Raman spectroscopy (VT‐Raman) is a useful and attractive tool for the sensitive in situ monitoring of lipid state changes and lipid melting. The LMs can incorporate D₂O into their structures regardless of preparation temperature due to increasing lattice distance by hydration. These results suggest that monitoring lipid structural changes during the heating step is important to precisely prepare target LMs. Practical Applications: This study reveals that VT‐Raman is a useful and attractive tool in in situ monitoring of lipid state change and lipid melting. The monitoring of the preparation process by VT‐Raman is necessary to precisely prepare the target LM similar to intercellular lipid of stratum corneum because the microstructures and thermal properties of these LMs change depending on the melting of lipid ingredients during the preparation process.