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421.
Lauric acid (m.p.: 42.6°C) and myristic acid (m.p.: 52.2°C) are phase change materials (PCM) having quite high melting points which can limit their use in low‐temperature solar applications such as solar space heating and greenhouse heating. However, their melting temperatures can be tailored to appropriate value by preparing a eutectic mixture of lauric acid (LA) and myristic acid (MA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 66.0 wt% LA forms a eutectic mixture having melting temperature of 34.2°C and the latent heat of fusion of 166.8 J g?1. This study also considers the experimental establishment of thermal characteristics of the eutectic PCM in a vertical concentric pipe‐in‐pipe heat storage system. Thermal performance of the PCM was evaluated with respect to the effect of inlet temperature and mass flow rate of the heat transfer fluid on those characteristics during the heat charging and discharging processes. The DSC thermal analysis and the experimental results indicate that the LA–MA eutectic PCM can be potential material for low‐temperature solar energy storage applications in terms of its thermo‐physical and thermal characteristics. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
422.
BACKGROUND: One of the problems in marketing fruit is to increase the share of fruits produced in sustainable agriculture to meet the expectation of ecology‐oriented consumers. Acceptability of such fruits by the consumers is of paramount importance. The objective of this study was to explore the acceptability of three scab‐resistant apple cultivars as compared with three popular conventional cultivars by Polish consumers of various age groups (adults, youngsters and children). Acceptability was tested on apples harvested in two consecutive years (2004 and 2005) after 2 months cold storage. Apple samples were chosen among 22 conventional and scab‐resistant cultivars for their distinctive differences in sensory profiles. Consumers evaluated separately the degree of external (appearance) and internal (flavour and texture) liking of an apple using a 9‐point hedonic scale (children used a 5‐point scale) and completed a questionnaire detailing socio‐demographic and apple‐concerning behavioural questions. RESULTS: The results based on internal liking data have shown that in all age groups, consumers were similarly segmented into three clusters: cluster 1, which liked all cultivars a great deal and equally; cluster 2, which preferred firm, juicy and rather acidic fruits; and cluster 3, which liked sweeter apples with intensive ripe apple flavour and moderate firmness. CONCLUSION: It is concluded that scab‐resistant cultivars with the above sensory characteristics might be accepted by quite a large segment of consumers, in each of the age groups tested. Copyright © 2009 Society of Chemical Industry  相似文献   
423.
Avinash  Mehmet  Kamil  Ravi   《Ad hoc Networks》2008,6(5):675-695
Network wide broadcast is a frequently used operation in ad hoc networks. Developing energy efficient protocols to reduce the overall energy expenditure in network wide broadcast can contribute toward increasing the longevity of ad hoc networks. Most of the existing work in energy efficient broadcast protocols use either a fixed transmission power model or assume global knowledge of the entire network at each node. Variable power broadcast with local knowledge has recently been proposed as a promising alternative approach for network wide broadcast in ad hoc networks.

In this paper, we present a novel approach, called INOP, for network wide broadcast. INOP is a variable power broadcast approach that uses local (two-hop neighborhood) information. INOP utilizes a novel technique for determining the transmission power level at each transmitting node. We also propose two alternative methods to cover the nodes that are not covered by the transmission of the source or a retransmitting node.

Our simulation based evaluations show that, compared to other approaches, INOP achieves better results in terms of energy efficiency, and competes with and exceeds other approaches in terms of a number of other performance metrics including traffic overhead, coverage, and convergence time. Based on these results, we can conclude that INOP improves the current state-of-the-art approaches for energy efficient broadcast in ad hoc networks.  相似文献   

424.
425.
针对维吾尔文手写体文本中行分割问题,基于连通域大小将图像中文字分为三类,提出了自适应涂抹细化算法,对主体文本行进行定位;并对第三类连通域中相邻两文本行间粘连的字符进行切割;此外,利用重心范围内的邻域搜索算法,解决了剩余笔画的文本行归附问题。实验结果表明,该方法与常见的水平投影法,分段投影法,及涂抹方法相比具有更好的分割效果。  相似文献   
426.
在笔迹图像中格线和噪音的去除、细化等预处理基础上,结合维吾尔文笔迹结构和书写风格,提出了一种基于四维笔划方向特征的笔迹鉴别技术。为了进一步提高其鉴别率,还将方向特征与较成熟的基于倾斜度的另一种方向特征进行了融合,取得了较好的实验结果。具体实施过程中,还对比分析了不同的特征距离度量方法对鉴别率的影响,确定加权欧式距离为最佳度量方法。  相似文献   
427.
The paper presents the results of the research on the impact of enzymatic liquefaction, freezing and thawing on the efficiency of juice pressure extraction from apple pulp and quality of the obtained juices. The research was conducted using three types of pretreatment prior the pressing: crushing and enzymatic liquefaction in temperature of 25 °C, crushing and enzymatic liquefaction in temperature of 45 °C and crushing followed by freezing and thawing of the pulp. The study included three varieties of apples. The juice was obtained using a laboratory basket press. It was determined that the pretreatment of the pulp as well as the varietal characteristics of the fruits have a significant impact on the efficiency of the pressure extraction process. The enzymatic treatment of the pulp, irrespective of the temperature at which it was conducted, significantly increased the efficiency of the process. No effect of the temperature (25 or 45 °C) of enzymatic treatment on the efficiency of the pressure extraction process was found. Pretreatment of the pulp based on freezing and thawing contributes to the increase of efficiency of pressing in the case of two apple cultivars, that is, Idared and Red Delicious. It was showed that total phenolic content, antioxidant activity, the soluble solids content and juice acidity (pH) depend on the pretreatment of the pulp and the varietal characteristics of apples. Following the application of pretreatment of the pulp, an increase was observed in the content of polyphenols and in the antioxidant activity of the juices obtained.  相似文献   
428.
Conducted a series of experiments with object-discrimination learning-set (ODLS) experienced blue jays. Exp. I demonstrated long-term retention of the ability to solve new ODLS problems, short-term retention loss of intraproblem information concerning specific problems after 2 acquisition trials, and a higher percentage correct following a reinforced Trial 1 response than following a nonreinforced Trial 1 response. Exp. II demonstrated that this Trial 1 outcome effect could be reversed with single-object Trial 1 procedures. Exp. III showed that when intraproblem retention testing was carried out later in each problem, after 5 acquisition trials, with a single-object Trial 1 procedure, the differential effect of Trial 1 outcome was eliminated. Exp. IV demonstrated that replacement of the stimulus chosen on Trial 1 disrupted Trial 2 performance, while replacement of the nonchosen object had no effect. Results are interpreted as consistent with a response-strategy view of the ODLS behavior of the blue jay similar to that based on research with macaque monkeys. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
429.
The increasing use of computers in statistics has spawned a new generation of multivariate statistical techniques. Chief among these is a tree-structured approach to classification and regression analysis. The CART, or Classification and Regression Trees, program implements a recursive partitioning procedure based on an iterative search for best binary "splits" of data. Resultant classifiers consist of binary trees whose leaves determine class labeling. Extensive use of data resampling techniques replaces biased classifier performance measures.  相似文献   
430.
The GPR18 receptor, often referred to as the N-arachidonylglycine receptor, although assigned (along with GPR55 and GPR119) to the new class A GPCR subfamily-lipid receptors, officially still has the status of a class A GPCR orphan. While its signaling pathways and biological significance have not yet been fully elucidated, increasing evidence points to the therapeutic potential of GPR18 in relation to immune, neurodegenerative, and cancer processes to name a few. Therefore, it is necessary to understand the interactions of potential ligands with the receptor and the influence of particular structural elements on their activity. Thus, given the lack of an experimentally solved structure, the goal of the present study was to obtain a homology model of the GPR18 receptor in the inactive state, meeting all requirements in terms of protein structure quality and recognition of active ligands. To increase the reliability and precision of the predictions, different contemporary protein structure prediction methods and software were used and compared herein. To test the usability of the resulting models, we optimized and compared the selected structures followed by the assessment of the ability to recognize known, active ligands. The stability of the predicted poses was then evaluated by means of molecular dynamics simulations. On the other hand, most of the best-ranking contemporary CADD software/platforms for its full usability require rather expensive licenses. To overcome this down-to-earth obstacle, the overarching goal of these studies was to test whether it is possible to perform the thorough CADD experiments with high scientific confidence while using only license-free/academic software and online platforms. The obtained results indicate that a wide range of freely available software and/or academic licenses allow us to carry out meaningful molecular modelling/docking studies.  相似文献   
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