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排序方式: 共有1210条查询结果,搜索用时 15 毫秒
1.
Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L−1), osmolality (mOsmol kg−1), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L−1 gallic acid), reducing and total sugars (%) and Na and K contents (mg L−1). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences.  相似文献   
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In this work, we investigated a procedure which exploits microwave ovens to produce SiC- based components by reactive melt infiltration of silicon into graphite preforms. The employed oven is designed to grant optical access to the sample surface, which allows to measure its temperature evolution though a noncontact pyrometer. This signal was used as a feedback to control the power provided to the preform and as an experimental output whose analysis provides insight into the reaction mechanism. Specifically, it is found that complete infiltration is achieved much before the end of the reaction. The latter is not fully self-sustained as the global reaction rate continuously decreases with time until it is no more able to keep the temperature above the silicon solidification value. At that point, the reaction stops. The analysis of the processed samples proved that this procedure allows producing fully infiltrated samples without material failure by adjusting the heat provided during the infiltration stage rather than by tuning the preform structure and composition, which is the usual approach. The proposed method is less time and energy consuming than the standard one.  相似文献   
4.
Guest Editorial: Wireless Mobile Internet   总被引:1,自引:0,他引:1  
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5.
This paper presents results of reliability investigation of 20 V N-Drift MOS transistor in 0.13 μm CMOS technology. Due to high performances required for CMOS applications, adding high voltage devices becomes a big challenge to guarantee the reliability criteria. In this context, new reliability approaches are needed. Safe Operating Area are defined for switch, Vds limited and Vgs limited applications in order to improve circuit designs. For Vds limited applications, deep doping dose effects in drift area are investigated in correlation to lifetime evaluations based on device parameter shifts under hot carrier stressing. To further determine the amount and locations of hot carriers injections, accurate 2D technological and electrical simulations are performed and permit to select the best compromise between performance and reliability for N-Drift MOS transistor.  相似文献   
6.
IEEE 802.11-saturation throughput analysis   总被引:1,自引:0,他引:1  
To satisfy the emerging need of wireless data communications, the IEEE is currently standardizing the 802.11 protocol for wireless local area networks. This standard adopts a CSMA/CA medium access control protocol with exponential backoff. We present a simple analytical model to compute the saturation throughput performance in the presence of a finite number of terminals and in the assumption of ideal channel conditions. The model applies to both basic and request-to-send/clear-to-send (RTS/CTS) access mechanisms. Comparison with simulation results shows that the model is extremely accurate in predicting the system throughput  相似文献   
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PURPOSE: To determine the association between lipids, microalbuminuria and systemic blood pressure. Urinary albumin excretion rate (AER) was determined in timed overnight urine samples by radioimmunoassay. Microalbuminuria was defined when two out of three urine samples had AER ranging 20-200 micrograms/min. Lipids were determined by colorimetric methods (total cholesterol, HDL cholesterol and triglycerides). METHODS: Fifty patients with insulin dependent diabetes mellitus (28 females, 22 males) aged 21.9 +/- 7 years and with diabetes duration of 6.8 +/- 5.8 years attending the outpatients diabetes clinic were studied cross-sectionally. RESULTS: Microalbuminuria was present in 12% of our patients. A high systolic blood pressure (SBP) was found in microalbuminuric patients (p = 0.003). No difference concerning serum lipids were found in comparison between normo and microalbuminuric patients, although 20% of all patients had increased cholesterol and LDL cholesterol and 4% had high HDL cholesterol and triglycerides levels. Stepwise multiple regression analysis showed that SBP was the only significant independent variable to influence AER (r = 0.42 r2 = 0.18 p = 0.002). CONCLUSION: Although in our study, microalbuminuria was associated only with SBP, the independent alteration of lipids in young IDDM patients must be considered as a possible additional risk factor for cardiovascular disease.  相似文献   
8.
This paper reviews the scholarship concerning the rise to economic prominence of the Italian industrial districts, and the causes of some of the difficulties in which some districts have found themselves since the mid-1980s. The paper develops the main lines of the economic advantages that districts enjoyed during a period of rapid growth, resulting from the operation of a market in common which blends competition and cooperation. The effects of globalisation are changing this somewhat ‘idyllic’ picture, as the structure of linkages between firms comes under pressure. Prospects for the Italian districts in these new circumstances are discussed.  相似文献   
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OBJECTIVE: To determine the efficacy and safety of vitamin D 50,000 units/week and calcium 1,000 mg/day in the prevention of corticosteroid induced osteoporosis. METHODS: A minimized double blind, placebo controlled trial in corticosteroid treated subjects in a tertiary care university affiliated hospital. The sample was 62 subjects with polymyalgia rheumatica, temporal arteritis, asthma, vasculitis, or systemic lupus erythematosus. The primary outcome measure was the percentage change in bone mineral density (BMD) of the lumbar spine in the 2 treatment groups from baseline to 36 mo followup. RESULTS: BMD of the lumbar spine in the vitamin D and calcium treated group decreased by a mean (SD) of 2.6% (4.1%) at 12 mo, 3.7% (4.5%) at 24 mo, and 2.2% (5.8%) at 36 mo. In the placebo group there was a decrease of 4.1% (4.1%) at 12 mo, 3.8% (5.6%) at 24 mo, and 1.5% (8.8%) at 36 mo. The observed differences between groups were not statistically significant. The difference at 36 mo was-0.693% (95% CI -5.34, 3.95). CONCLUSION: Vitamin D and calcium may help prevent the early loss of bone seen in the lumbar spine as measured by densitometry of the lumbar spine. Longterm vitamin D and calcium in those undergoing extended therapy with corticosteroids does not appear to be beneficial.  相似文献   
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