Utilization of soybean vinasse for α-galactosidase production

The enzyme α-galactosidase was produced by submerged fermentation using as substrate the soybean vinasse, a residue of the alcoholic fermentation of soybean molasses. Soybean molasses is a by-product of the protein-concentrate soybean meal production. The strain Lactobacillus agilis LPB 56 was selected among nine for presenting the highest enzymatic activity. The C:N relation in the vinasse-based inoculum medium was optimized and adjusted in 6 with yeast extract. The effects of soluble solids concentration in the fermentation medium, C:N relation and size of inoculum were investigated. Results demonstrated that the medium concentration of 30% soluble solids, with a C:N relation of 9, and size of inoculum of 25% (v/v) were the best conditions for α-galactosidase production. The highest enzyme activity (11.07 U/mL) was achieved after 144 h of fermentation.     

Design of transmission line filters and matching circuits using genetic algorithms

A method for designing microwave filters and impedance matching circuits using transmission lines is presented. Transmission line filters with shunt‐connected open circuit stubs and continuously varying transmission line matching circuits are described in detail. The proposed method is based on genetic algorithms and can effectively be applied to various filter and matching circuit design problems without increasing theoretical and computational complexity. Design examples are provided, and the proposed method is demonstrated to be effective in designing transmission line filters and matching circuits. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Design of nonlinear shaft torque observer for trucks with Automated Manual Transmission

Knowledge of drive axle shaft torque improves the longitudinal dynamic performance of vehicles. An axle shaft torque observer is proposed for vehicles with stepped ratio transmissions, which is a class of switching systems. Model uncertainties, including the steady state error and the unmodeled dynamics, are considered as an additive disturbance input and the observer is designed such that the error dynamics is input-to-state stable for all gear positions. The lowest possible gain of the designed observer is achieved by solving a set of LMIs. In the designed reduced-order observer, the complex nonlinear characteristics of powertrain systems are included and appears as their usual form of MAPs. Finally, the proposed observer is tested on an AMESim powertrain simulation model of a medium-duty truck.     

Development of new analytical method based on beta-alpha coincidence method for selective measurement of 214Bi-214Po-application to dust filter used in radiation management

The radionuclide pair (214)Bi and (214)Po which belongs to the uranium series interferes with airborne radionuclide measurement needed for the radiation management of a nuclear facility. Time intervals between (214)Bi (β) and (214)Po (α) are much shorter than artificial radionuclides due to the short half-life of (214)Po (164 μs). The purpose of this study is to develop of a new analytical method (time interval analysis: TIA) based on the beta-alpha coincidence method for selective measurement of (214)Bi-(214)Po. The developed method was applied to an actual dust-filter measurement. The TIA system was highly effective in measuring of the filter with background subtraction.     

URANS simulations for a free-running container ship:Part 2.Added power

Part 2 reports the validation,local force and local flow study results for the free-running added power simulations whose conditions are the same as the self-pr...     

Aromaticity of coal extract by 1H and 13C pulsed n.m.r. methods

High-resolution gated decoupling ¹³C spectra of soluble materials such as coal extracts have been analysed to evaluate the carbon aromaticity (f_a). A correlation was found between f_a and the reciprocal of the square of the shorter component in spin—spin relaxation time (T₂), which was obtained by pulsed ¹H n.m.r. in the solid state at low temperature. Values of carbon aromaticity for several coals as received were estimated by using the above correlation and compared with those by van Krevelen's densimetric method.     

Interaction between coal and liquefaction catalysts studied by high temperature electron spin resonance

The high temperature electron spin resonance technique has been used to obtain in situ information on the behaviour of liquefaction catalysts during coal pyrolysis. The spin concentration in coal was induced in the presence of a catalyst at the pyrolysis temperature. ZnCl₂ drastically increased the spin concentration of coal. The order of activity of the catalysts with respect to the increase in spin concentration was: ZnCl₂ (impregnated) ?ZnCl₂ (dispersed) >ZnCl₂/KCl>SnCl₂ > SbCl₃≈AlCl₃ ≈CaCl₂ > coal alone.     

Inhibitory Effects of ‘Enokitake’ Mushroom Extracts on Polyphenol Oxidase and Prevention of Apple Browning

‘Enokitake’ mushroom (Flammulina velutipes) extracts were prepared by three different solvents: 70 mL/100 mL acetone, 70 mL/100 mL ethanol as well as hot water. Effects of the extracts on mushroom tyrosinase activity and browning of apple were investigated. Mushroom tyrosinase activities assayed spectrophotometrically and by oxygen uptake were found to be inhibited significantly by all three extracts. Lyophilized ‘enokitake’ fruit body powder inhibited the browning of fresh apple. Immersing sliced apple into the acetone extract was found to prevent effectively the browning development. Freshly squeezed apple juice with added hot-water extract showed the concentration-dependent inhibition of browning. No browning was observed on the apple juice when mixed with the extract containing 1.0 g wet ‘enokitake’/mL in a mixture. Under the same conditions, no significant changes in color in terms of a* and b* values of the mixture were observed for up to 6 h. These observations suggested that ‘enokitake’ mushroom contained certain compounds which inhibited mushroom tyrosinase activity and the development of browning induced by the catalytic oxidation due to polyphenol oxidase.     

A multiuser interference cancellation technique utilizingconvolutional codes and orthogonal multicarrier modulation for wirelessindoor communications

This paper suggests that multicarrier modulation reduces the complexity and the delay caused by the multiuser interference cancellation process utilizing convolutional codes. For spread spectrum multiple access, multiuser interference (interference due to signals from other users) limits the performance of the communication link. To remove this interference, a multiuser interference cancellation technique which utilizes orthogonal convolutional codes has been proposed for the uplink (mobiles to a base station) of the cellular code-division multiple-access (CDMA) systems. However, this technique requires large interleavers and huge memory, or artificial multipath diversity and a RAKE system to achieve sufficient coding gain if it is applied to wireless indoor communications and fading is slow compared to the data rate. To reduce the complexity of the canceller, multicarrier modulation is employed as it provides frequency diversity gain and coding gain without the interleavers or a RAKE system. This paper shows that multicarrier modulation reduces the complexity of the canceller and still provides sufficient coding gain in order to cancel the multiuser interference. A canceller with decoding in the initial decision and multicarrier modulation improves the capacity by a factor of 1.4 as compared with a canceller without decoding