STORAGE OF RETORT POUCH BEEFSTEAK AND BEEF STEW PACKED UNDER FOUR HEADSPACE LEVELS

Changes in specific physico-chemical and sensory attributes as well as acceptability of beefsteak and beef stew Meal-Ready-to-Eat (MRE) components packed under different headspace levels (10, 20, 30 and 40 cm³) and stored at selected temperatures of 4, 27 and 38C (40, 80 and 100F) were evaluated over a six month period. No significant changes in microbial counts, pH, residual oxygen, color, hardness and oxidation occurred in retort-packed beefsteak or beef stew. Unlike beefsteak, beef stew received acceptable scores by consumers during all six months of analysis. Consumers' lack of familiarity with beefsteak may have negatively influenced product acceptability. Beefsteak and beef stew acceptability and specific attributes, particularly moistness and firmness, were detrimentally affected by high storage temperatures. Headspace may be increased to 40 cm³ without significant detrimental effects on product quality and acceptability of beefsteak or beef stew.     

Contamination of the Chalk Aquifer by Chlorinated Solvents: A Case Study of the Luton and Dunstable Area

A detailed investigation of contamination by chlorinated solvents of the Chalk Aquifer underlying the towns of Luton and Dunstable was undertaken to assess the extent, causes and mechanisms of pollution. The research programme incorporated land-use surveys, regional groundwater surveys, monitoring of groundwater abstraction points and aquifer profiling by means of the drilling of observation boreholes, the analysis of the recovered core material and the depth sampling of these and other boreholes.
Low-level solvent contamination of the Chalk Aquifer was found to be widespread with 'hotspots'of higher concentrations. At the drilling sites, both the saturated and unsaturated zones were contaminated with solvents, although free product was not observed. The presence of an additional contaminant, oil, at some sites was noted to influence the distribution of solvents within the aquifer.
Clean-up of the aquifer is not a practical option, and treatment of the groundwater at the abstraction points has been adopted.     

What do web users do? An empirical analysis of web use

This paper provides an empirical characterization of user actions at the web browser. The study is based on an analysis of 4 months of logged client-side data that describes user actions with recent versions of Netscape Navigator. In particular, the logged data allow us to determine the title, URL and time of each page visit, how often they visited each page, how long they spent at each page, the growth and content of bookmark collections, as well as a variety of other aspects of user interaction with the web. The results update and extend prior empirical characterizations of web use. Among the results we show that web page revisitation is a much more prevalent activity than previously reported (approximately 81% of pages have been previously visited by the user), that most pages are visited for a surprisingly short period of time, that users maintain large (and possibly overwhelming) bookmark collections, and that there is a marked lack of commonality in the pages visited by different users. These results have implications for a wide range of web-based tools including the interface features provided by web browsers, the design of caching proxy servers, and the design of efficient web sites.     

从用户角度看芯片贴装头技术

现代制造商一直特别看重在变动过程中迅速重新配置平台型贴装机的灵活性,以便能够对变动后的产品实现最优的贴装能力.现在,平台型贴装设备上提供的新一代贴装头技术扩展了这些系统的能力,可以提供高速芯片贴装功能,实现能够在不需重新配置,不会影响精度、良品率或产能的情况下,贴装常用的各种元件.它能使未来几代装配商将从更加灵活、自适应和精确的贴装头中受益,他们将提高利用率,大大降低变动时间,明显减少支持高速度、低成本、快速交货周期制造环境所需的反应时间.     

ACCR导线的现场试验

ACCR导线是种新型导线,它看上去与传统的ACSR基本相同,但它是由合成材料和耐热铝合金组成.它的主要特点是高强度、重量轻(钢芯的1/3),良好的传导性能(钢芯的3倍)以及热膨胀系数低(钢芯的1/2),因此可以在低弛度重量大线段替代钢导线.美国在2个不同地点对这种新型导线进行现场试验,以验证其各种性能.     

An agile manufacturing workcell design

This paper introduces a design for agile manufacturing worked Is intended for light mechanical assembly of products made from similar components (i.e., parts families). We define agile manufacturing as the ability to accomplish rapid changeover from the assembly of one product to the assembly of a different product. Rapid hardware changeover is made possible through the use of robots, flexible part feeders, modular grippers, and modular assembly hardware. The division of assembly, feeding, and unloading tasks between multiple robots is examined with prioritization based upon assembly time. Rapid software changeover will be facilitated by the use of a real-time, object-oriented software environment utilizing graphical simulations for off-line software development. An innovative dual VMEbus controller architecture permits an open software environment while accommodating the closed nature of most commercial robot controllers. These agile features permit new products to be introduced with minimal downtime and system reconfiguration.     

COMPUTER-AIDED ANALYSIS AND DESIGN OF AN ATP REGENERATION REACTOR

The two coupled reactions catalyzed by the enzymes adenylate kinase and acetate kinase for the regeneration of ATP from AMP in a CSTR were analyzed to obtain information required for the design of such a reactor. Unconventional but efficient computational methods were developed to handle the difficulty associated with the extremely complex rate expressions involved.     

Thermal Aggregation Properties of Duck Salt-Soluble Proteins at Selected pH Values

Thermal aggregation properties of duck breast and leg salt-soluble proteins (SSP) were studied at pH 5.50, 5.75 and 6.00. At pH 5.50, a major transition for breast was observed at 60.3°C and for leg at 41.8°C. At pH 5.75, major transitions at 44.6 and 43.2°C were obtained, respectively, for the breast and leg SSP. Three transitions at 46.0, 53.0 and 59.0°C were exhibited by breast SSP at pH 6.00, whereas only two major transitions at 47.4 and 54.0°C were identified in leg SSP. Changes in transition peak heights and shifts in transition temperatures as a result of pH changes indicated that, depending on fiber type, pH may enhance or suppress the aggregation behavior of specific constituents of the myosin/actomyosin complex, thereby altering the overall aggregation pattern of the protein preparation.