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81.
Color selection has always been a classic problem in exterior color design for the simple reason that façade color is commonly chosen at the architect's office, regardless of different external conditions affecting color perception. This issue often leads to an apparent discrepancy between the selected color and the perceived color of façade. So far, extensive research has been carried out to identify, classify, and study the influence of these conditions on perceived color. However, little attention has been paid to the importance of color attributes. Hence, this article attempts to grasp better the significance of chromaticness, as briefly discussed in earlier studies, in the variation pattern of perceived color while daylight condition differs. In order to determine perceived color, each test subject was asked to compare the color seen on the façade to the standard color samples of natural color system index and choose the matching one, using a designed color‐measuring device. The results obtained from 93 participants demonstrate 3 things: First, they further support the belief that perceived color is influenced in both hue and nuance under varied daylight circumstances. Second, they confirm previous findings that indicated chromaticness would affect the extent of color shifts. And above all, a comparison of the results reveals that façade colors of higher chromaticness values have had less shifts in hue, yet greater shifts in whiteness. Finally, the findings suggest that chromaticness together with the external conditions, under which the color is to be seen, should be carefully considered when selecting the façade color.  相似文献   
82.
Optimal conditions for microwave‐assisted extraction (MAE) of total phenols (TP), epicatechin gallate and antioxidant activity from prune (Prunus domestica), rejected in transformation process of plum to prune, were determined by response surface methodology. The central composite design was used to study the effects of three independent variables: microwave power, irradiation time and solvent polarity on the TP, epicatechin gallate and antioxidant activity. Epicatechin gallate was identified as a major phenolic compound in prune extract by RP‐HPLC. Microwave power and irradiation time significantly affected all responses (P < 0.01). The highest TP (598.89 mg GAE/100 g prune) was obtained using water as an extraction solvent at 500 W, during 115 s. However, the optimal conditions for epicatechin gallate extraction were ethanol 80%, 435 W and 120 s. MAE is more efficient than conventional extraction method to obtain TP from prune. The experimental values were reasonably close to the predicted values confirming the validity of the predicted models.  相似文献   
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84.
Skin ageing is an irreversible process that is caused by both intrinsic and extrinsic factors. The possibility of arresting or delaying skin ageing represents a large research area and has a big potential in the cosmetics sector. Recently, the polypeptide lysine-threonine-threonine-lysine-serine (KTTKS) has attracted a lot of attention and it features in numerous up-market cosmetic products where it has become erroneously associated with the term 'pentapeptide'. In this study, we review in detail KTTKS and its major derivatives, in terms of the limited information in the literature and an appraisal of its physicochemical and theoretical skin permeation properties. There appears to be a sound in vitro basis for its action on fibroblasts due to its stimulatory effect on extracellular matrix synthesis, where the stimulatory effect of KTTKS is specific to collagen types I and III and fibronectin expression. However, there is a surprising absence of in vitro skin penetration data in the literature, and there are relatively few clinical studies using these materials.  相似文献   
85.
The use of raw clay in housing construction dates back from ancient times and is still living on. Traditional habitat comprising various buildings all over different places of our planet, give evidence. Among any other pathologies affecting naked earthen walls, the rain water wash remains a major concern and deserves careful consideration. Which justifies the interest of this research focused on the protection means of such types of walls. This article relates the experiment conducted on low walls made out of raw clay mixed with composite protecting products (traditional and modern ones as well), being tested to intensive water floods. The result of the tests assessed through efficiency of the protecting materials, shows that the locust bean tree (local tree) fruit husk extract added to raw clay mortar and carefully blended seems to provide better ability to protect walls against water assault. Moreover, consistency check and plasticity reveal better performance in clay material properties.  相似文献   
86.
Out-of-context analysis of water resources systems can result in unsustainable management strategies. To address this problem, systems thinking seeks to understand interactions among the subsystems driving a system??s overall behavior. System dynamics, a method for operationalizing systems thinking, facilitates holistic understanding of water resources systems, and strategic decision making. The approach also facilitates participatory modeling, and analysis of the system??s behavioral trends, essential to sustainable management. The field of water resources has not utilized the full capacity of system dynamics in the thinking phase of integrated water resources studies. We advocate that the thinking phase of modeling applications is critically important, and that system dynamics offers unique qualitative tools that improve understanding of complex problems. Thus, this paper describes the utility of system dynamics for holistic water resources planning and management by illustrating the fundamentals of the approach. Using tangible examples, we provide an overview of Causal Loop and Stock and Flow Diagrams, reference modes of dynamic behavior, and system archetypes to demonstrate the use of these qualitative tools for holistic conceptualization of water resources problems. Finally, we present a summary of the potential benefits as well as caveats of qualitative system dynamics for water resources decision making.  相似文献   
87.
88.
Kurosh Madani 《电信纪事》1993,48(11-12):537-545
The increase in integration density and in complexity of moderns integrated circuits and systems revealed the necessity to consider the testability problem at the design level of circuits. One of the most active research areas in circuits design, over the past decade, has been the implementation of neural networks as electronic VLSI chips. Especially, the implementation of artificial neural networks (ANN) as CMOS integrated circuits shows several attractive features. Recent studies point out that classification is their most successful application field, and thus large networks will be required. Unfortunately, very few papers analyse the testability of electronic implementation of artificial neural networks. A large number of artificial neural networks models deal with binary output neurones. This paper presents and discuss a global current measurement based pseudo-analogue technique for digital-output electronic neural networks testing. Two approaches have been presented and their limitations have been discussed. Simulation results and a method validation test circuit have been presented.  相似文献   
89.
In this work, calcium carbonate nanoparticles-polyethylene oxide nanofibers as organic-inorganic hybrid were prepared via in-situ electrospinning. Thus, electrospinning of polyethylene oxide solution saturated with calcium hydroxide was carried out in gaseous carbon dioxide atmosphere. Transmission electron microscopy (TEM) showed that calcium carbonate (CaCO3) nanoparticles were formed on the produced nanofibers of 200-300 nm in diameter. The existence of the formed CaCO3 was also proved by thermogravimetric analysis (TGA) via loss of gaseous CO2 related to the decomposition of CaCO3 at about 500-840 degrees C. X-ray diffraction (XRD) analysis of the nanofibers showed that the formed CaCO3 nanoparticles have vaterite morphology. DSC analysis was used to determine melting point and to calculate the crystallinity of the produced hybrid nanofibers. The TEM, TGA, XRD and DSC analyses results of the obtained nanofibers were compared with those of the nanofibers produced in electrospinning of pure polyethylene oxide solution and polyethylene oxide solution having calcium hydroxide, both in air.  相似文献   
90.
The thermolysin catalysed hydrolysates of α-lactalbumin and β-casein were fractionated by size-exclusion chromatography (SEC) and reversed-phase high performance liquid chromatography (RP-HPLC) in order to identify the peptides responsible for the high ACE-inhibitory activity of these hydrolysates. The SEC fractionation separated many co-eluting peptides into different fractions allowing individual peptides to be isolated in one or two subsequent semi-preparative RP-HPLC fractionation steps. Five potent ACE-inhibitory peptides from α-lactalbumin were isolated. They all contained the C-terminal sequence -PEW, corresponding to amino acid residues 24–26 in α-lactalbumin, and had IC50 values of 1–5 μm. From one SEC fraction of the β-casein hydrolysate two potent ACE-inhibitory peptides were isolated and identified as f58-76 and f59-76 of β-casein A2. They both contained IPP as the C-terminal sequence and had IC50 values of 4 and 5 μm. From another SEC fraction a new but less ACE-inhibitory peptide from β-casein was identified (f192–196; LYQQP).  相似文献   
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