Biochemical changes in an intermediate moisture cecina-like meat during storage

Biochemical and microbiological changes in two cecina-like products were evaluated during storage. Two products were prepared, one by salting and the other by infusion in a salt-glycerol solution. The samples were vacuum packed and tested monthly for pH, colour, haematin complex, soluble nitrogen and microbiological spoilage. Proteolysis and increase in pH showed a high correlation for both samples. Temperature-dependent changes in colour and concentration of haematin complex during storage were also found in both samples. The activation energy for haematin transformation was found to be around 1 kcal/mol. Based on the low activation energy for haematin complex degradation (around 1 kcal/mol) for both samples, this process may be regarded as a low energy biochemical process.     

Performance enhancement in an uninhabited air vehicle task using psychophysiologically determined adaptive aiding

OBJECTIVE: We show that psychophysiologically driven real-time adaptive aiding significantly enhances performance in a complex aviation task. A further goal was to assess the importance of individual operator capabilities when providing adaptive aiding. BACKGROUND: Psychophysiological measures are useful for monitoring cognitive workload in laboratory and real-world settings. They can be recorded without intruding into task performance and can be analyzed in real time, making them candidates for providing operator functional state estimates. These estimates could be used to determine if and when system intervention should be provided to assist the operator to improve system performance. METHODS: Adaptive automation was implemented while operators performed an uninhabited aerial vehicle task. Psychophysiological data were collected and an artificial neural network was used to detect periods of high and low mental workload in real time. The high-difficulty task levels used to initiate the adaptive automation were determined separately for each operator, and a group-derived mean difficulty level was also used. RESULTS: Psychophysiologically determined aiding significantly improved performance when compared with the no-aiding conditions. Improvement was greater when adaptive aiding was provided based on individualized criteria rather than on group-derived criteria. The improvements were significantly greater than when the aiding was randomly provided. CONCLUSION: These results show that psychophysiologically determined operator functional state assessment in real time led to performance improvement when included in closed loop adaptive automation with a complex task. APPLICATION: Potential future applications of this research include enhanced workstations using adaptive aiding that would be driven by operator functional state.     

The approximation of image blur restoration filters by finite impulse responses

Image blur can often be modeled by a linear spatially invariant, symmetric point spread function. For this class of functions, several restoration filters are known in the literature. The approximation of their frequency transfer functions (ftf's) by the ftf's of small finite impulse response (FIR) filters has been studied. Accurate approximations will be possible by 9 × 9 FIR's with 8-bit elements if the approximation is done in a weighted MMSE sense, and if the truncation of the element values will be carried out such that the errors are small. A heuristic truncation algorithm MINIM will be described. An example of restoration by a 9 × 9 FIR will be shown.     

非线性热耦合和相变可动边界的BEM分析

§1．引言近20年来，耦合问题（CoupledProblems）揭示了实验难以发现的一些新现象、新机理．[1,2]将耦合问题分为两大类，即不同介质间同一物理场的耦合和同一介质间两种物理场的耦合．［3-7］属第一类，统称为力学耦合［29，30］．变形或流动与热效应之间的耦合属第二类，其中瞬变温度场和相变可动边界问题有待深入研究．这类问题具有多种非线性，有限元（FE）模式涉及可变区域[19,20]，变分原理和网格重分均较复杂．八十年代初开始用BE模式作瞬时传热模型[8]，随后推广到带相变面[9]z但迄今为止，这类数学模型提出不少，极不统一完整…     

X-47B舰载无人作战机即将进行试飞

X-47B无人作战航空系统验证机（UnmannedCombmAirSystemDemonstrator,UCAS．D）将在帕图克森特河海军航空站（简称帕站）进行试飞。有关人士称,首架x47B初始飞行试验将于2012年夏天进行,第2架飞机也将从爱德华兹基地转场过来,对其进行拦阻着舰和弹射起飞试验。     

美国航天民用产品实例连载一--电缆故障检测仪

航天技术是人类20世纪最伟大的技术进步之一,它在拉动尖端科学技术发展和国防实力提升的同时,已走进国民经济的各个领域。本刊高科技窗口栏目从即日起将连续介绍美国航天民用产品实例,通过介绍产品实物图像、应用对象、市场规模等信息,展示航天技术在工业、人民生活、医疗、环保、节能等各方面的应用。篇幅所限仅以提供产品信息为主(有关技术方面的信息,可登陆www.sti.nasa.gov网站查询),旨在启迪思想,期望对航天民品的发展起到抛砖引玉的作用。     

Effect of a novel soy fermented product enriched with isoflavones and calcium on bone tissue of rats

The objective was to evaluate the effect of soy fermented product intake on the corporal weight and bone tissue of ovariectomized mature rats. This product was fermented with Enterococcus faecium and Lactobacillus jugurti and enriched with isoflavones and calcium. The animals were divided in 5 groups: sham-ovariectomized; ovariectomized; ovariectomized treated with soy fermented product enriched with isoflavones and calcium; ovariectomized treated with soy fermented product enriched with calcium and ovariectomized treated with non-fermented product enriched only with calcium. In order to evaluate the effect of the tested product on bone tissue (femur and tibia), the following parameters were analyzed: length; mechanical assay of three points; density (Archimedes principle); mineral content; calcium content; measure of the trabecular widths. The corporal weight of group treated with soy fermented product containing isoflavones and calcium showed no statistical difference from sham-ovariectomized group and trabecular widths tended to have larger than ovariectomized group. However, there was no significant difference to the other evaluated parameters in result of the diverse treatments. Thus, soy fermented product enriched with isoflavones and calcium inhibited the increasing of corporal weight caused by ovariectomy and revealed a tendency to trabecular protection after castration.