Limonoid Debittering of Citrus Juice Sera By Immobilized Cells of Corynebacterium fascians

Corynebacterium fascians cells capable of metabolizing limonoids were prepared conveniently with inexpensive carbon sources such as fructose, galactose and citric acid. Cells thus obtained were immo-bilized in acrylamide gel and used in a biological debittering process previously developed. The process significantly reduced limonin and nomilin contents of citrus juice sera. It was particularly effective toward the reduction of nomilin. The debittering treatment did not have adverse effects on the composition of other citrus constituents such as citric, malic, ascorbic acids, fructose, glucose and sucrose.     

Limonoid Glucosides in Fruit, Juice and Processing by-products of Satsuma Mandarin (Chus unshiu Marcov.)

In a study on improving utilization of waste from processing of Satsuma mandarin (Citrus unshiu Marcov.) the limonoid glucosides of fruit, juice, and by-products were measured using HPLC and TLC. All materials had the 17-β-D-glucopyranoside derivatives of limonoids reported in other commercial citrus fruit. Citrus molasses was a good source for industrial scale extraction of limonoid glucosides. An extraction system using polystyrene divinylbenzene resins, was developed which could be expanded to industrial scale.     

Survival of Lactic Acid Bacteria during Spray Drying of Plain Yogurt

Survival of Streptococcus salivarius subsp. thermophilus and Lactobacillus debrueckii subsp. bulgaricus was determined under various processing conditions for spray drying. Numbers of both microorganisms decreased with increased outlet or inlet air temperature, and atomizing air pressure. Outlet air temperature was a major parameter affecting number of survivors. Suitable conditions were inlet air 160°C, outlet air 60°C, atomizing air pressure 98 kPa, hot air flow 0.28 m³/ min, and feed temperature 30°C. Spray-dried yogurt powder showed lower survival for S. thermophilus and similar survival for L. bulgaricus as compared to freeze-dried powder.     

Fabrication and properties of YBa2Cu3O7-δAg composite superconducting wires by plastic extrusion technique

YBa₂Cu₃O_7-δ (Y123)-Ag composite superconducting wires were fabricated by the plastic extrusion method which involves plastic paste making, die extrusion, binder burn-out and the firing process. The as-extruded Y123-Ag wires were so flexible that they can be easily fabricated into a desirable shape. The current-carrying properties of the wire are dependent on sample size, sintering temperature and silver content. The critical current density, J _c, of the Y123 wire with a large cross-section was lower than that of the wires with a small cross-section, probably due to the large self-induced magnetic field. J _c of the Y123-Ag wires increased with increasing sintering temperature but abruptly decreased above 910 °C, which is close to the eutectic temperature of the Y–Ba–Cu–O system. A silver addition of 10–20 wt% slightly increased J _c of the Y123 (at 77 K and 0 T, it was 140 and 250 A cm ^-2 for the undoped Y123 wire and the Y123 wire with 20 wt% Ag addition, respectively), but further silver addition had a deleterious effect on J _c (180 A cm ^-2 for 30 wt% Ag addition). The small increment in J _c in the Y123 wire with 10–20 wt% Ag addition appears to be due to the enhanced densification and the associated microstructural variation. The decreased J _c of the Y123 wire with 30 wt% Ag addition is considered to be due to the formation of non-superconducting phase, Y₂BaCuO₅ (Y211), BaCuO₂ and CuO phases via the decomposition of the Y123 phase. This revised version was published online in November 2006 with corrections to the Cover Date.     

微滤技术/紫外线辅助催化臭氧氧化组合工艺处理洗车废水中试研究

用微滤技术/紫外线(MF/UV)辅助催化臭氧氧化组合工艺进行洗车废水处理回用的中试研究,结果表明操作压力≤20 kPa时,膜通量长期稳定.膜滤对COD、TN、TP和SS的去除率分别达到69.74%、40.12%、37.81%和100.00%,但膜滤对阴离子表面活性剂(LAS)基本没有去除效果.UV辅助催化臭氧氧化对膜滤出水进一步降解,系统出水水质良好,符合生活杂用水水质标准(CJ/T48-1999).     

Simultaneous formation of machine and human cells in group technology: a multiple objective approach

Since the advent of group technology (GT) as a primary manufacturing tool for reducing setup times and improving production efficiencies, its central theme has been the grouping of similar parts into part families and machines into machine cells. Although the formation of machine-part manufacturing cells is the essence of GT, its full benefits cannot be gained without forming ‘human’ cells in such a way that machine operators with similar expertise and skills are brought together to produce similar part families. Nevertheless, much of the existing GT literature overlooks the behavioural issues associated with a group of workers in the machine cell. This paper addresses such issues by simultaneously forming both machine and compatible human cells. In so doing, we develop a multiple objective model that enables us to analyse the tradeoff between economic and behavioural benefits.     

PIEZOELECTRICALLY DRIVEN MICROTRANSDUCER MASS SENSORS

ABSTRACT

Various types of piezoelectrically driven microtransducers which have a similar physical dimension, i.e., microcantilever, microdiaphragm and microbridge, were fabricated by micro electromechanical system (MEMS) technique and are compared on the mass sensing behavior. The diol based sol-gel derived Pb(Zr_0.52,Ti_0.48)O₃ (PZT) thin film capacitors were integrated for the piezoelectric actuation. We have used the resonant frequency change of microtransducer upon mass increase as a sensing mechanism. The resonant frequency of the microtransducer was measured by analysis of electrical signals from microtransducer such as impedance, capacitance, phase and dielectric loss. The fundamental resonant frequencies of the microcantilever, microbridge and microdiaphragm with similar dimension (～300 μm) were about 26 kHz, 260 kHz and 290 kHz, respectively. The mass sensitivities of bare microtransducers were measured by metallic thin film deposition and analysis of spectral responses from microtransducers. When various microtransducers are compared, the microcantilever exhibited the highest gravimetric sensitivity factor (Δf/Δm×f₀ = 694.4 cm²/g), followed by the microbridge and microdiaphragm. However, the microbridge showed the highest mass sensitivity (Δf/Δm = 137.5 Hz/ng) among those transducers.     

CHARACTERIZATIONS OF GALLIUM AND ARSENIC CO-DOPED ZnO THIN FILMS DEPOSITED BY PULSED LASER DEPOSITION TECHNIQUE

ABSTRACT

Gallium and arsenic doped ZnO thin films (0.1 at.%) were deposited at different temperatures by using pulsed laser deposition technique. An x-ray diffractometer was used to investigate the structural properties of the thin films. It is found that the thin films have a preferred (002) orientation, and the peak intensity of the (002) orientation increases with increasing growth temperature. Atomic force microscope was used to investigate the surface morphologies of the thin films. The grain size and roughness of the thin films depend on the growth temperature. A spectrophotometer was used to measure the transmittances of the thin films. The band gap energies of the thin films were calculated by linear fitting the sharp absorption edge of high-quality thin films. It is found that, the band gap energies of gallium and arsenic co-doped ZnO thin films are larger than the pure ZnO due to Burstein-Moss effect, and the band gap energy decreases with increasing growth temperature. A spectrometer was used to investigate the luminescent properties of the thin films. All of the thin films show near band edge emission and no deep-level emissions are observed. This is believed to be the compensation of the oxygen vacancies. Hall measurements indicate that all the thin films are n-type semiconductor and the doped thin film grown at 400°C is the most conductive and has the highest mobility.