Identification of bottom-fermenting yeast genes expressed during lager beer fermentation

It has been proposed that bottom-fermenting yeast strains of Saccharomyces pastorianus possess at least two types of genomes. Sequences of genes of one genome [S. cerevisiae (Sc)-type] have been found to be highly homologous (more than 90% identity) to S. cerevisiae S288C sequences, while those of the other [Lager (Lg)-type] are less so. To identify and discriminate Lg-type from Sc-type genes expressed during lager beer fermentation, normalized cDNA libraries were constructed and analysed. From approximately 22 000 ESTs, 3892 Sc-type and 2695 Lg-type ORFs were identified. Expression patterns of Sc- and Lg-type genes did not correlate with particular cell functions in KEGG classification system. Moreover, 405 independent clones were isolated that have no significant homology with sequences in the S288C database, suggesting that they include the bottom-fermenting yeast-specific (BFY) genes. Most of BFY genes have significant homology with the S. bayanus genome.     

Preparation and characterization of high‐quality rice bran proteins

Rice bran contains 120–200 g kg^?1 protein in addition to a large amount of fat, carbohydrate, and phytic acid. Rice bran protein (RBP) fractions were refined by a two‐step preparation to eliminate residual carbohydrate. The first step involved the sequential extraction of defatted rice bran into RBP fractions using their distinct solubility to give 37 g kg^?1 of albumin, 31 g kg^?1 of globulin, 27 g kg^?1 of glutelin, and 2 g kg^?1 of prolamin. In the second step, carried out by dissolving in respective solvent and isoelectric precipitation, the protein content of each fraction increased from 69% to 97% for albumin, from 71% to 90% for globulin, from 74% to 83% for glutelin, and from 18% to 20% for prolamin. The low protein content in the prolamin fraction might be due to its low solubility in the protein assay. Emulsifying stability index and surface hydrophobicity increased in the second‐step preparation of albumin and globulin, but not of glutelin. Emulsifying properties of RBPs were lower than that of a soybean protein isolate. Denaturation temperatures and enthalpy values of denaturation for albumin, globulin, glutelin, and prolamin were 50.1 °C/1.2 J g^?1, 79.0 °C/1.8 J g^?1, 74.5 °C/3.0 J g^?1, and 78.5 °C/8.1 J g^?1, respectively. No significant differences in the denaturation temperatures and enthalpy values of denaturation of RBP fractions were obtained with these two‐step preparations (P < 0.05). Copyright © 2007 Society of Chemical Industry     

Introduction of compressive residual stress into stainless steel by employing a cavitating jet in air

In order to eliminate stress corrosion cracking, a method of introduction of compressive residual stress using cavitation impacts was proposed, without use of shots. The cavitation impacts were successfully produced by a cavitating jet in air, without the requirement of a water-filled chamber. The injection condition of the jet was optimized and the introduction of compressive residual stress into stainless steel was demonstrated using the jet. The maximum compressive residual stress introduced by the optimized jet was 500 MPa on the surface, while the thickness of the modified layer was up to 400 μm. A method for estimation of the introduced compressive residual stress by the jet as a function of processing time was proposed, considering the stochastic phenomena of the cavitation impacts. Both the intense impact at 0.2 Hz and relatively weak impact at 4.5 Hz affect the introduction of compressive residual stress. The value of the residual stress and the thickness of the modified layer can be estimated by the proposed experimental equation.     

Multi-probe scanning system comprising three laser interferometers and one autocollimator for measuring flat bar mirror profile with nanometer accuracy

This paper describes a multi-probe scanning system comprising three laser interferometers and one autocollimator to measure a flat bar mirror profile with nanometer accuracy. The laser interferometers probe the surface of the flat bar mirror that is fixed on top of a scanning stage, while the autocollimator simultaneously measures the yaw error of the scanning stage. The flat bar mirror profile and horizontal straightness motion error are reconstructed by an application of simultaneous linear equations and least-squares method. Measurement uncertainties of the flat bar mirror profile were numerically evaluated for different installation distances between the laser interferometers. The average measurement uncertainty was found to be only 10 nm with installation distances of 10 and 21 mm between the first and second, and first and third interferometers, respectively. To validate the simulation results, a prototype system was built using an X–Y linear stage driven by a stepper motor with steps of 1 mm along the X direction. Experiments were conducted with fixed interferometers distances of 10 and 21 mm, as in the simulation, on a flat bar mirror with a profile known to an accuracy of λ = 632.8 nm. The average value of two standard deviations (95%) of the profile calculated over ten experiments was approximately 10 nm. Other results from the experiment showed that the system can also measure the yaw and horizontal straightness motion errors successfully at a high horizontal resolution. Comparing with the results measured by ZYGO's interferometer, our measured data excluding some edge points showed agreement to within approximately 10 nm. Therefore, we concluded that our measurement profile has an accuracy in the nanometer range.     

Control of Collection Efficiency for Axial Flow Cyclone Dust Collectors with Fixed Guide Vanes and with Funnel Shaped Exit Pipes

The experimental result of the collection efficiency of the axial flow cyclone with the fixed guide vanes is lowerthan that with the tangential inlet pipe to the cyclone body due to the weak angular momentum transfer given byflowing through the guide vanes.However,one of the interesting points is the control of the collection efficiencydepended on the funnel shaped exit pipes.The collection efficiencies for these funnel shaped exit pipes aredepended on the Froude number.Then,in this paper,the experimental results of the pressure drop and also thecollection efficiency using the fly-ash particles and also the comparison of the calculated results of the collectionefficiency with the experimental results are described in detail.     

Improvement of color reproduction in color digital holography by using spectral estimation technique

We propose a color digital holography by using spectral estimation technique to improve the color reproduction of objects. In conventional color digital holography, there is insufficient spectral information in holograms, and the color of the reconstructed images depend on only reflectances at three discrete wavelengths used in the recording of holograms. Therefore the color-composite image of the three reconstructed images is not accurate in color reproduction. However, in our proposed method, the spectral estimation technique was applied, which has been reported in multispectral imaging. According to the spectral estimation technique, the continuous spectrum of object can be estimated and the color reproduction is improved. The effectiveness of the proposed method was confirmed by a numerical simulation and an experiment, and, in the results, the average color differences are decreased from 35.81 to 7.88 and from 43.60 to 25.28, respectively.     

Nature of hydrogen bonding of water molecules in aqueous solutions of glycerol by attenuated total reflection (ATR) infrared spectroscopy

Attenuated total reflection infrared (ATR-IR) spectroscopy was performed on glycerol/water solutions in order to gain a better understanding of the strong hydrogen bonding of glycerol as a humectant. The OH stretching band after eliminating the contribution of glycerol OH in the glycerol/water solutions was decomposed using three Gaussian components. With increasing glycerol concentrations up to 50 volume %, the decrease of the 3428 cm(-1) component (middle H-bond component) and the increase of the 3562 cm(-1) component (longer H-bond component) suggested the breaking of H bonds among water molecules. On the other hand, the 3242 cm(-1) component (shorter H-bond component) remained unchanged. It was expected that water molecules surrounding glycerol molecules are retained by strong H bonding between H atoms of water and O atoms in C-O of glycerol when aqueous solutions containing glycerol are introduced in human skin.     

Inhibition of hydrogen fermentation of organic wastes by lactic acid bacteria

The effects of lactic acid bacteria (LAB) on hydrogen fermentation of organic waste were investigated. For this three hydrogen producing strains of Clostridium were cultured with two lactic acid bacteria, i.e. Lactobacillus paracasei and Enterococcus durans, which were isolated from the wastes generated in the bean curd manufacturing. The decrease or cessation of hydrogen production by Clostridium was caused by the addition of LAB. The supernatants of L. paracasei and E. durans suspensions also inhibited hydrogen production by Clostridium. This inhibition was partially destroyed in the presence of trypsin, which is a protease inactivating a bacteriocin. These results suggest that the inhibitory effect of lactic acid bacteria on hydrogen production was caused by bacteriocins excreted from LAB which have a deleterious effect on other bacteria. To suppress any effect by LAB, heat treatment of this waste was investigated as a possible pretreatment step. The inhibition of hydrogen production was reduced by heat treatment for 30 min at temperatures ranging from 50°C to 90°C. This means that a temperature of 50°C is already adequate to prevent growth of LAB.     

Solar to chemical conversion using metal nanoparticle modified microcrystalline silicon thin film photoelectrode

Microcrystalline silicon (μc-Si:H) thin films, which are prospective low-cost semiconductor materials, are used as photoelectrodes for the direct conversion of solar energy to chemical energy. An n-type microcrystalline cubic silicon carbide layer and an intrinsic μc-Si:H layer are deposited on glassy carbon substrates using the hot-wire cat-CVD method. The μc-Si:H electrodes are modified with platinum nanoparticles through electroless displacement deposition. The electrodes produce hydrogen gas and iodine via photoelectrochemical decomposition of hydrogen iodide with no external bias under solar illumination. Surface modification with platinum nanoparticles and surface termination with iodine improve the conversion efficiency.     

Measurements of induced activity in concrete by secondary particles at forward direction produced by intermediate energy heavy ions on an Fe target

Spallation and neutron capture reaction rate distributions were measured using activation detectors inside a 90-cm thick ordinary concrete pile exposed to a field of secondary particles escaping a thick (stopping length) iron target bombarded with various intermediate energy ions, 230 MeV/u He, 400 MeV/u C, and 800 MeV/u Si. Activation detectors of aluminum, bismuth, gold, and gold covered with cadmium were inserted at various depths in the concrete pile. In addition, the distributions of activation reaction rate were simulated by FLUKA and PHITS Monte-Carlo codes. Generally, comparison of measured and calculated reaction rates show agreement within a factor of two. The experimental data will be useful for benchmarking Monte-Carlo radiation transport simulation code capabilities in estimating radioactivity induced in accelerator radiation shielding.