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31.
The objective of this research is to present a novel electronic device that will be used in the investigation process for data logging and plotting the l-V and P-V curves for each PV technology used. The novelty of this device lies in the fact that it is integrated within the test bed keeping in mind the limitations in size, area available and cost. Cost reduction for such devices could be one step in tackling the worldwide engineering challenge in making solar power an economic solution.  相似文献   
32.
We present a detailed analysis of a 2R optical regenerator based on self-phase modulation in As(2)Se(3) chalcogenide glass fiber using frequency-resolved optical gating (FROG). We obtain good agreement between the FROG measurements and theory, and confirm that the output pulses are near-transform limited. We show that two-photon absorption improves the profile of the power transfer function while not degrading the temporal performance.  相似文献   
33.
Whole body leucine kinetics was compared in endurance-trained athletes and sedentary controls matched for age, gender, and body weight. Kinetic studies were performed during 3 h of rest, 1 h of exercise (50% maximal oxygen consumption), and 2 h of recovery. When leucine kinetics were expressed both per unit of body weight and per unit of fat-free mass, both groups demonstrated an increase in leucine oxidation during exercise (P < 0.01). Trained athletes had a greater leucine rate of appearance during exercise and recovery compared with their sedentary counterparts (P < 0.05) and an increased leucine oxidation at all times on the basis of body weight (P < 0.05). However, all of these between-group differences were eliminated when leucine kinetics were corrected for fat-free tissue mass. Therefore, correction of leucine kinetics for fat-free mass may be important when cross-sectional investigations on humans are performed. Furthermore, leucine oxidation, when expressed relative to whole-body oxygen consumption during exercise, was similar between groups. It is concluded that there was no difference between endurance-trained and sedentary humans in whole body leucine kinetics during rest, exercise, or recovery when expressed per unit of fat-free tissue mass.  相似文献   
34.
DNA mismatch repair ensures genomic stability by correcting biosynthetic errors and by blocking homologous recombination. MutS-like and MutL-like proteins play important roles in these processes. In Escherichia coli and yeast these two types of proteins form a repair initiation complex that binds to mismatched DNA. However, whether human MutS and MutL homologs interact to form a complex has not been elucidated. Using immunoprecipitation and Western blot analysis we show here that human MSH2, MLH1, PMS2 and proliferating cell nuclear antigen (PCNA) can be co-immunoprecipitated, suggesting formation of a repair initiation complex among these proteins. Formation of the initiation complex is dependent on ATP hydrolysis and at least functional MSH2 and MLH1 proteins, because the complex could not be detected in tumor cells that produce truncated MLH1 or MSH2 protein. We also demonstrate that PCNA is required in human mismatch repair not only at the step of repair initiation, but also at the step of repair DNA re-synthesis.  相似文献   
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Since 1950 we have known that bubbles forming at orifices interact with the gas in the chamber below the orifice. This paper (1) presents a mechanistic model of that interaction based on a simple material balance, and a consideration of the pressure-time history of a forming bubble; (2) shows the model's experimental confirmation over a wide range of variables; (3) shows a theoretical lower chamber-volume limit to the applicability of this model and confirms it experimentally; (4) shows an approximate upper chamber-volume limit to the applicability of the model, and shows that this limit is experimentally confirmed, at least approximately; and (5) shows that the observed pressure-time behavior in the chamber is in accord with the above-described model and its limits.  相似文献   
38.
Synoname1: The Getty's new approach to pattern matching for personal names  相似文献   
39.
We present a complete software control architecture for synchronizing multiple data streams generated from distributed media-storing database servers without the use of a global clock. Independent network connections are set up to remote workstations for multimedia presentations. Based on the document scenario and traffic predictions, stream delivery scheduling is performed in a centralized manner. Certain compensation mechanisms at the receiver are also necessary due to the presence of random network delays. A stream synchronization protocol (SSP) allows for synchronization recovery, ensuring a high quality multimedia display at the receiver. SSP uses synchronization quality of service parameters to guarantee the simultaneous delivery of the different types of data streams. In the proposed architecture, a priority-based synchronization control mechanism for MPEG-2 coded data streams is also provided. A performance modeling of the SSP is presented using the DSPN models. Relevant results such as the effect of the SSP, the number of synchronization errors, etc., are obtained  相似文献   
40.
BACKGROUND: Forty children who underwent the antegrade continence enema (ACE) procedure for faecal soiling were studied to determine factors predictive of outcome. METHODS: There were four patient groups: (1) ambulant with spinal dysraphism (n = 13), (2) wheelchair bound with spinal dysraphism (n = 14), (3) ambulant with miscellaneous disorders (n = 11) and (4) wheelchair bound with miscellaneous disorders (n = 2). Effectiveness of the procedure was assessed using technical evaluation and quality-of-life improvement (QOLI) scores (0-5). Objective assessment included colonic transit time (CTT) and anorectal manometry. Median follow-up was 21 (range 5-37) months. RESULTS: Some 28 of 40 children achieved continence. The procedure was reversed in four of 40 children. Of the other 36 children with a functioning ACE stoma, all reported improvement in quality of life (mean QOLI score 3.5). There were no significant differences in technical evaluation score, QOLI score, CTT, manometry findings or continence between ambulant groups and the wheelchair-bound group with miscellaneous disorders. QOLI score, anorectal squeeze pressure and continence were significantly poorer in those who were wheelchair bound with spinal dysraphism. Absent squeeze pressure was associated with poor outcome. CONCLUSION: Wheelchair-bound children with spinal neuropathy have a poorer outcome following the ACE procedure. Although ACE is an effective method of promoting faecal continence, it is essential to determine the aetiology of incontinence and sphincter function before operation.  相似文献   
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