Bioproduction of Perillyl Alcohol and Related Monoterpenes by Isolates of Bacillus stearothermophilus

Bacillus stearothermophilus BR388 was isolated from orange peel by an enrichment culture using (+)-limonene. The thermophilic isolate exhibited growth between 45 and 68°C., with optimum growth near 55°C. BR388 could grow on limonene as a sole carbon source, but grew and degraded limonene more effectively when supplemented with small amounts of yeast extract. Perillyl alcohol was the major conversion product, with α-terpineol and perillyl aldehyde as minor products. Strains of B. stearothermophilus previously isolated from aromatic enrichments also grew on limonene, but had higher sensitivity to limonene toxicity than did BR388.     

TEXTURE STABILITY OF HYDROGEL COMPLEX CONTAINING CURDLAN GUM OVER MULTIPLE FREEZE–THAW CYCLES

The texture stability of hydrogel complexes containing curdlan gum over multiple freeze–thaw cycles (FTCs) was investigated. The hydrogels formed by curdlan and xanthan gum, locust bean gum, carrageenan or guar gum at various combinations were stored at 4C for 24 h before subjected to five FTCs alternating between − 16 (18 h) and 25C (6 h). Xanthan/curdlan hydrogels showed the highest freeze–thaw stability in terms of syneresis, heat stability and adhesiveness. The viscosity of xanthan/curdlan combination was the lowest among all samples studied yet the most stable over the five FTCs, whereas significant changes were observed with locust bean/curdlan hydrogels. The guar/curdlan combination before freeze–thaw treatments exhibited predominant elasticity; however, as the cycles progressed the elasticity decreased. The most stable gel strength was achieved when curdlan was combined with guar or xanthan at 2% (w/v) total concentration, while carrageenan/curdlan gels were the least stable.

PRACTICAL APPLICATIONS

Texture instability remains the most significant challenge for frozen food products, especially with inevitable post-production temperature fluctuations. Loss of moisture and changes in textural attributes often results in significant reduction of product quality. Precise control of hydrogel complexes that provide texture stabilization over multiple freeze–thaw cycles will enhance the quality of existing products while enabling the development of new ones.     

顶壳

在旧金山的约瑟夫·L·阿利奥托演艺广场,面对着旧金山市政厅,最南端的美国梧桐的顶部4500镑新伐的柳枝交织,一系列的圆锥体构成了这个“顶壳”,使其看起来就像自然生长的树木一样——春华秋实。     

逆向供应链

逆向供应链是指企业为了从客户手中回收使用过的产品所必需的一系列活动。其目的是对回收品进行处置,或者再利用。研究表明,有效的逆向供应链能够提升顾客满意度,同时增加企业利润。其中对退换货物的处理,也就是逆向物流一环更成为很多企业提升竞争力的利器。公司只要仔细分析自身的逆向物流链,就可能发现其中还有许多可以改进之处。     

Human reasoning about artificial intelligence

Abstract

Recently, several authors (Searle, Penrose, Rychlak) have suggested that AI is a doomed undertaking. In his recent book, Artificial Intelligence and Human Reasoning, Joseph Rychlak repeats many of the arguments of the other critics, as well as offering several of his own. In this paper, taking Rychlak as symptomatic of this new anti-computational intellectual movement, we respond to these arguments and defend AI and personal construct theory against some of the misunderstandings and confusions which we find there.     

ROTOR MODELING AND DEVELOPMENT FOR BRUSHLESS DOUBLY-FED MACHINES

ABSTRACT

The basic principles of brushless doubly-fed machine (BDFM) synchronous operation are used to establish the essential components of the rotor configuration and alternative types of construction are examined. Certain forms, which appear to be physically realizable only with wound or fabricated rotors, are dismissed in favor of others which may be fabricated or die-cast in a manner similar to the cage rotors of conventional induction machines.

A detailed simulation model is used to predict the performance of a proof-of-concept laboratory machine in a motoring mode which has been correlated with test data. Various developments and options of the rotor configuration are then examined for relative performance at two different speeds using the modeling techniques. The design features considered include (i) alternative interpretations of the nested-loop configuration requirement, (ii) number of rotor loops per nest, (iii) location (span) of rotor loops, and (iv) conductor section of specific rotor bars and end rings.