Synchrony effects in inhibitory control over thought and action.

Two experiments explore whether synchrony between peak circadian arousal periods and time of testing influences inhibitory efficiency for younger and older adults. Experiment 1 assesses inhibitory control over no-longer-relevant thoughts, and Experiment 2 assesses control over unwanted but strong responses, as well as performance on neuropsychological tasks that index frontal function. Inhibitory control is greatest at optimal times for both age groups and is generally greater for younger than for older adults. Performance on 2 neuropsychological measures (Stroop and Trails) also changes over the day, at least for older adults, and is correlated with inhibitory indexes, suggesting that for older adults changes in inhibition may be mediated by circadian variations in frontal functioning. By contrast, access to well-learned responses is not vulnerable to synchrony or age effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of immunosuppression and splenectomy in transplantation sarcomas in mice

After spontaneous regression of transplanted tumours, marked reduction in number of tumours was found when challenged with isogenic tumour cells. The ALS abrogates this effect. Tumour removal by surgical excision of limb and subsequent time scheduled challenge by tumour cells maximally suppress on the 10th day and continues up to the 42nd day the tumorogenic effect. Splenectomy has no effect if done before a day or 3 days after challenge but marked decrease in tumour development was seen when challenged on the 8th day after splenectomy. Amputation and splenectomy together potentiates tumour formation. Only in tumour extrication, does resistance develop up to the 42nd day from surgery. Challenging at a different site in mice with tumours, resulted in prolongation of the intervals of tumour formation. Challenge after surgical removal of tumour after a time lapse, results in marked reduction in number and size of tumours. Surgical tumour extrication after splenectomy and subsequent challenge on 11th day inhibited tumour formation. Whereas splenectomized tumour bearing mice when challenged at a heterosite did not develop resistance.     

Hydrogen-assisted cracking

This article reviews a number of case studies involving hydrogen-assisted cracking in steels. Before the case studies are presented, the current state of understanding of hydrogen-assisted cracking is briefly reviewed. At present there are two leading approaches to the development of a mechanism of hydrogen-assisted cracking, one based upon bond weakening, and the other upon strain localization. As the case studies illustrate, hydrogen-assisted cracking can lead to failures in perhaps unexpected circumstances. The need for the wider dissemination of information about hydrogen cracking to design engineers is indicated.     

Economic Comparison of NdFeB and Hard Ferrites in Automotive Applications

With the increasing use of electric motors in automobiles—in some cases as many as 100 electric motors per vehicle—alternatives to ferrite magnetic materials are under consideration. If more powerful magnetic materials could be implemented, size reductions in these motors could result in curb weight reductions that lead to improved fuel economy. NdFeB magnets are attractive as potential replacement materials, due to their higher flux density and thus smaller required size; however, high material costs have limited their implementation. To investigate the economic competitiveness of alternative magnetic materials, technical cost models (TCMs) were developed and used to examine the manufacturing economics related to the production of both NdFeB and ferrite magnets. Results from the TCMs are used to identify the cost drivers and opportunities for cost reductions. Subsequent investigations will include effects on vehicle fuel efficiency, and the environmental impact of magnet manufacture and disposal.     

智能型激光控制器提高灵活性并节省空间

激光二极管是宽带调幅光纤发射系统的核心器件。光纤系统依赖于激光的稳定性,但未受调节控制的激光二极管特性却常因制造误差、温度和使用日久所造成的参数改变而变得不稳定。因此,光纤通信系统需要专用电路来控制重要的激光二极管参数,以确保它们稳定操作。虽然激光控制电路都