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51.
Sunlight is an important factor in regulating the central circadian rhythm, including the modulation of our sleep/wake cycles. Sunlight had also been discovered to have a prominent influence on our skin’s circadian rhythm. Overexposure or prolonged exposure to the sun can cause skin photodamage, such as the formation of irregular pigmentation, collagen degradation, DNA damage, and even skin cancer. Hence, this review will be looking into the detrimental effects of sunlight on our skin, not only at the aspect of photoaging but also at its impact on the skin’s circadian rhythm. The growing market trend of natural-product-based cosmeceuticals as also caused us to question their potential to modulate the skin’s circadian rhythm. Questions about how the skin’s circadian rhythm could counteract photodamage and how best to maximize its biopotential will be discussed in this article. These discoveries regarding the skin’s circadian rhythm have opened up a completely new level of understanding of our skin’s molecular mechanism and may very well aid cosmeceutical companies, in the near future, to develop better products that not only suppress photoaging but remain effective and relevant throughout the day.  相似文献   
52.
The sound speeds and densities of the 1-propanol + diethyl ether + 1-octanol ternary mixture and constituent binary mixtures, 1-propanol + diethyl ether, 1-propanol + 1-octanol, and diethyl ether + 1-octanol, have been measured at 298.15 K as a function of composition. Isentropic compressibilities, molar isentropic compressibilities, excess molar isentropic compressibilities, excess molar volumes, and excess sound speeds have been calculated from the experimental density and sound speed data. Excess molar volumes, excess molar isentropic compressibilities, and excess sound speeds of the binary mixtures were fitted to the Redlich–Kister equation. By using the free length theory (FLT), Schaaff’s collision factor theory (CFT), Nomoto’s relation (NR), Van Deal’s ideal mixing relation (IMR), and Junjie’s relation (JR), sound-speed values of the investigated mixtures were calculated. These values were compared with the experimental sound-speed results.  相似文献   
53.
Drying properties of textiles in summer and/or after any kind of physical activity resulted in sweating is of great importance for garments with high clothing comfort. This study analyzes the drying behavior of knitted fabrics produced from various fibers at different ambient air conditions. Drying kinetics and modeling of fabrics dried in standard environmental conditions were investigated in the first part. Polyester and lyocell fabrics were found to be the fastest drying samples. A two-stage modeling that is a combination of linear approach and thin-layer equations was used, and the best fitted equation was found to be the logarithmic one. The two-stage model was also proved to predict the drying rate. The second part included the effects of ambient humidity on drying times and rates. Drying time of polyester and polyester blended fabrics was affected by the increase in the humidity to a great extent. Furthermore, a quadratic function was found to be highly correlated with the computed data, so it was proposed to define the drying behavior by ambient air humidity and drying time.  相似文献   
54.
The coverage optimization problem has been examined thoroughly for omni-directional sensor networks in the past decades. However, the coverage problem in directional sensor networks (DSN) has newly taken attraction, especially with the increasing number of wireless multimedia sensor network (WMSN) applications. Directional sensor nodes equipped with ultrasound, infrared, and video sensors differ from traditional omni-directional sensor nodes with their unique characteristics, such as angle of view, working direction, and line of sight (LoS) properties. Therefore, DSN applications require specific solutions and techniques for coverage enhancement. In this survey article, we mainly aim at categorizing available coverage optimization solutions and survey their problem definitions, assumptions, contributions, complexities and performance results. We categorize available studies about coverage enhancement into four categories. Target-based coverage enhancement, area-based coverage enhancement, coverage enhancement with guaranteed connectivity, and network lifetime prolonging. We define sensing models, design issues and challenges for directional sensor networks and describe their (dis)similarities to omni-directional sensor networks. We also give some information on the physical capabilities of directional sensors available on the market. Moreover, we specify the (dis)advantages of motility and mobility in terms of the coverage and network lifetime of DSNs.  相似文献   
55.
Journal of Materials Science: Materials in Electronics - In this study, synthesis and determination of physical, optical, and radiation shielding properties of glasses based on TeO2 and GeO2 were...  相似文献   
56.
Infrared heating was recently used to develop a more efficient roasting technology than traditional hot air roasting. Therefore, in this study, we evaluated the shelf-life of almonds roasted with three different approaches, namely infrared (IR), sequential infrared and hot air (SIRHA) and regular hot air (HA). Nine medium roasted almond samples produced by the aforementioned heating methods were processed at three different temperatures (130, 140 and 150 °C), packed in paper bags and then stored at 37 °C for three, six or eight months. Shelf-life of the roasted almonds was determined by measuring the changes in colour, peroxide value, moisture content, water activity, volatile components and sensory quality. No significant difference was observed in moisture content and water activity among the almond samples processed with different roasting methods and stored under the same conditions. GC/MS analysis showed that aldehydes, alcohols, and pyrazines were the main volatile components of almonds. Aliphatic aldehydes such as hexanal, (E)-2-octenal, and nonanal were produced as off-odours during storage. Although the overall quality of roasted almonds produced with SIRHA and HA heating was similar during the first three months of storage, their peroxide value and concentration of aliphatic aldehydes differed significantly for different roasting methods and increased significantly in all roasted samples during storage. We postulate that hexanal and nonanal might be better indicators of the shelf life of roasted almonds than the current standard, peroxide value.  相似文献   
57.
Iranian Polymer Journal - This study presents the tribological behavior of epoxy matrix composites containing two different fillers. The composites contain fillers with different particle sizes...  相似文献   
58.
59.
Infrared heating for dry-roasting and pasteurization of almonds   总被引:1,自引:0,他引:1  
The use of infrared (IR) heating for improving the microbial safety and processing efficiency of dry-roasted almonds was investigated. Almonds were roasted at 130, 140 and 150 °C with three different methods: IR roasting, sequential infrared and hot air (SIRHA) roasting, and traditional hot air (HA) roasting. The heating rate and pasteurization efficacy of almonds under different roasting methods and temperatures were evaluated. Pediococcus sp. NRRL B-2354 was used as a surrogate for Salmonella enterica Enteriditis PT 30 for evaluating the pasteurization efficacy of different processing methods and conditions. When SIRHA roasting at 130, 140 and 150 °C roasting temperatures was used to produce medium roasted almonds, 4.10-, 5.82- and 6.96-log, bacterial reductions were achieved with 38%, 39% and 62% time saving compared to HA roasting at each temperatures, respectively. The decimal reduction time of the bacteria at all roasting temperatures were calculated for SIRHA roasting as 8.68, 3.72 and 1.42 min, respectively, with a correlation coefficient greater than 0.92 and the thermal resistance constant was found as 25.4 °C. The total color change followed zero-order reaction kinetics and the activation energies were 73.58, 52.15 and 67.60 kJ/mol for HA, IR and SIRHA roasting, respectively. No significant difference (p > 0.05) was observed in sensory quality of medium roasted almonds processed with different roasting methods. We conclude that the SIRHA roasting is a promising new method for the production of dry-roasted pasteurized almonds.  相似文献   
60.
A procedure for the determination of trace amounts of chromium(III), iron(III), lead(II) and manganese(II) is described, that combines atomic absorption spectrometry-europium hydroxide coprecipitation. The influences of analytical parameters including amount of europium(III), amount of ammonia, sample volume, etc. were investigated on the recoveries of analyte ions. The effects of concomitant ions were also examined. The recoveries of the analyte ions were in the range of 95-104%. The detection limits (3 s) were in the range of 1.7-17.1 microg/L. The validation of the presented coprecipitation procedure was performed by the analysis of Bovine Liver 1577-b and BCR-144R Sewage Sludge (domestic origin) standard reference materials. The method was applied to the determination of analytes in real samples including natural waters and some food, soil and fertilizer samples, etc. and good results were obtained (relative standard deviations < 10%, recoveries > 95%).  相似文献   
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