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41.
An experimental study of thermal energy storage with phase change materials by design of experiments
Accurate theoretical modelling and simulation of thermal energy storage (TES) by means of phase change materials (PCM) is very complex and its results are not close enough to experimental values. This paper presents the empirical study of a thermal storage unit operating with a commercial PCM called RT25. The study is carried out by means of the statistical procedure, Design of Experiments. This methodology has rarely been used in the analysis of heat transfer problems. The present study has allowed us to investigate the phenomena involved and to design an actual system. We show the whole procedure followed in order to design the set-up, to run the experiments with a 23 factorial design, to compare its results with a numerical simulation and to get the empirical model by regression. Its results have been used to design actual installations aimed at free-cooling or maintaining the temperature constant in rooms where thermal security is necessary. 相似文献
42.
介绍了用激光光热反射方法测量表面下物体热物性的实验原理.分析了实验中噪声的主要来源,运用带通滤光片结合差分探测的方式降低激光器产生的噪声.锁相放大技术对被测信号进行窄带放大,锁相放大器结合示波器输出了被测信号的周期变化部分,实现了光热法测量中微弱信号的测量. 相似文献
43.
热模拟是毫米波中高功率放大器设计中的关键环节之一,可靠的散热结构可确保系统中有源器件工作在额定温度下,而基于有限元方法的数值模拟技术是毫米波功率放大器热分析的重要工具。针对由四块毫米波功率单片合成的Ka频段6W固态集成功放,采用有限元软件ANSYS建立了其三维热模型,对模型在空气自然对流情况下的温度分布状况进行了模拟和分析,模拟结果与实测值基本吻合,验证了模型的有效性。研究结果对毫米波功率放大器的热设计提供了重要的理论依据。 相似文献
44.
Stephanos Ioannou Paul Morris Hala Hassanain Marc Baker Faisal Alkattan Abdul Hakim Almakadma Lama Raddaoui 《Infancy》2021,26(3):352-368
Physiological adaptations to external stressors can reveal socio-cognitive health in infancy. With the use of thermal imaging and behavioural analyses, the current study examined the arousal markers accompanying infants’ interactions with a familiar and an unfamiliar person. To address the current research question, the mother and a complete stranger interacted with 2 to 3 month-old infants (N= 10, 2 boys)in three different conditions: Neutral, Play, and Compliment. Behavioral analyses showed that overall gaze was longer to the Stranger compared to the Mother independent of condition. Physiological findings showed that skin temperature was significantly higher with the stranger independent of condition. The regions of the face that passed the significance threshold included the maxillary area, the nose, and the forehead. Both behavioral and physiological findings emphasize the ability of the infant to distinguish between a familiar and an unfamiliar person. Most importantly, however thermal imaging has proven to be a promising tool in physiologically differentiating between variable social conditions in very young infants opening up a new experimental portal for identifying healthy physiological development. 相似文献
45.
喷涂工艺薄膜厚度模型的构建与应用 总被引:1,自引:0,他引:1
为研究12寸晶圆切割过程中喷涂工艺设备参数对保护性薄膜厚度的影响,提高设备调整效率和工艺质量,采用均匀设计的实验方法,以薄膜在测试量块上的厚度为目标,对影响厚度的主要因素:涂料压力、微调阀和雾化压力进行研究。对实验数据采用SPSS进行非线性逐步回归得到了薄膜厚度的数学模型,揭示了各因素的交互关系,为测机调整提供数据依据,节省大量反复测机时间,在保证工艺质量的同时提高了喷涂设备的生产效率。该模型已成功运用于某芯片封装测试厂的喷涂设备,并取得了显著效果。 相似文献
46.
47.
采用聚甲基丙烯酸甲酯(PMMA)芯片,以甲基纤维素(MC)作为动态改性剂,在系统优化分离条件的基础上,利用芯片电泳技术,在90s内实现了4种脂肪胺类化合物的快速分析。 相似文献
48.
电子枪在工作过程中产生的高温易导致各个组件变形,影响电子枪的各项性能指标和工作寿命,热分析在提高电子枪设计的可靠性和加快研制周期方面起着重要的作用。该文使用ANSYS软件对行波管电子枪进行了热分析和结构分析,比较了电子枪复杂模型和简化模型的温度和热形变计算结果。热分析结果对电子枪的优化设计有参考价值。 相似文献
49.
重庆温泉旅游资源开发研究 总被引:3,自引:0,他引:3
刘焱 《重庆邮电学院学报(社会科学版)》2006,18(2):194-197
温泉旅游在重庆旅游整体发展战略中具有重要的地位,然而目前对其整体开发利用的学术研究还较鲜见。重庆温泉旅游资源独具特色,开发条件良好,市场潜力大。但是目前在开发上却存在多头管理、定位泛化、产品设计缺乏创新、市场促销不力等问题。因此在综合研究的基础上提出了改革它的经营体制、引进先进管理模式、提升规划档次、设计多样化产品及树立品牌、整体促销等策略。 相似文献
50.
Certain respiratory tract infections can be transmitted by hand-to-mucous-membrane contact, inhalation, and/or direct respiratory droplet spray. In a room occupied by a patient with such a transmissible infection, pathogens present on textile and nontextile surfaces, and pathogens present in the air, provide sources of exposure for an attending health-care worker (HCW); in addition, close contact with the patient when the latter coughs allows for droplet spray exposure. We present an integrated model of pertinent source-environment-receptor pathways, and represent physical elements in these pathways as "states" in a discrete-time Markov chain model. We estimate the rates of transfer at various steps in the pathways, and their relationship to the probability that a pathogen in one state has moved to another state by the end of a specified time interval. Given initial pathogen loads on textile and nontextile surfaces and in room air, we use the model to estimate the expected pathogen dose to a HCW's mucous membranes and respiratory tract. In turn, using a nonthreshold infectious dose model, we relate the expected dose to infection risk. The system is illustrated with a hypothetical but plausible scenario involving a viral pathogen emitted via coughing. We also use the model to show that a biocidal finish on textile surfaces has the potential to substantially reduce infection risk via the hand-to-mucous-membrane exposure pathway. 相似文献