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Low noise cryogenic system for the measurement of Casimir energy in rigid cavities  [PDF]
Giuseppe Bimonte,Detlef Born,Enrico Calloni,Giampiero Esposito,Uwe Huebner,Evgeni Il'ichev,Luigi Rosa,Francesco Tafuri,Ruggero Vaglio
Physics , 2007, DOI: 10.1088/1751-8113/41/16/164023
Abstract: We report on preliminary results on the measurement of variations of the Casimir energy in rigid cavities through its influence on the superconducting transition of in-cavity aluminium (Al) thin films. After a description of the experimental apparatus we report on a measurement made with thermal photons, discussing its implications for the zero-point photons case. Finally we show the preliminary results for the zero-point case.
大型高速低温风洞冷量回收的方法研究
Cold Energy Recycle from Cryogenic Wind Tunnel Exhaust System
 [PDF]

赖欢,陈振华,高荣,陈万华,刘秀芳,侯予
- , 2016, DOI: 10.7652/xjtuxb201606021
Abstract: 为提高低温风洞排气冷量的综合利用和节能减排,实现大型低温风洞科学建设,分析了目前大型低温设备冷量回收利用的现状和方法;针对低温风洞高雷诺数试验运行中排气系统的工作流程和特点,对大型高速低温风洞排气冷量进行了初步计算,结合当前低温工质气化冷量回收技术方案的流程分析和国内外低温系统冷量回收利用的技术特点,对低温风洞液氮喷雾制冷后冷量回收与高效利用的方法和可行性进行了初步研究。综合考虑技术难度和投资经济性,提出了通过蓄冷设备、空分装置、固态氮制取进行冷量回收的3种主要技术途径。分析结果表明:采用蓄冷设备需要周边用冷设备支持,回收效率低;利用空分装置无需额外投资,经济性较好;固态氮制取回收效率高,硬件投资大,经济性较差。通过合理调整风洞试验流程,选取合适的技术方案,可以实现大型低温风洞的冷量回收。
To promote the usage of potential cold energy from exhaust system of cryogenic wind tunnel, realize scientific construction and energy saving, the status and methods of cold energy recycle are discussed. The operating processes and features of exhaust system in high Reynolds number testing are introduced and the cold energy from cryogenic wind tunnel exhaust system is calculated preliminarily. Based on the process analysis of oversea cold energy recycle schemes from cryogenic fluids gasification and the technical features of domestic cold energy recycle schemes, the recovery and efficient utilization of cold energy from liquid nitrogen spray cooling in cryogenic wind tunnel are studied. Considering the technology feasibility and economical efficiency, three expected cryogenic energy recycle schemes are provided, including a storage of the exhaust energy for civil air??conditioning, re??liquefying the gaseous nitrogen through an air separation process and using solid nitrogen as the cooling source. The advantages and disadvantages of the above??mentioned three approaches are analyzed. The first scheme has a low recycling rate because of the necessary additional cold??consuming equipment; the second scheme has an acceptable recycling rate and a good economical efficiency without additional investment; the third scheme has a good recycling rate but the further higher investment. Thus an appropriate recycle scheme and a reasonable wind tunnel testing process are important for cryogenic wind tunnel exhaust energy recycling
On the energy conservation by weak solutions of the relativistic Vlasov-Maxwell system  [PDF]
Reinel Sospedra-Alfonso
Mathematics , 2009,
Abstract: We show that weak solutions of the relativistic Vlasov-Maxwell system preserve the total energy provided that the electromagnetic field is locally of bounded variation and, for any $\lambda$> 0, the one-particle distribution function has a square integrable $\lambda$-moment in the momentum variable.
Electrical Energy Conservation in Automatic Power Factor Correction by Embedded System
Energy and Power , 2012, DOI: 10.5923/j.ep.20120204.02
Abstract: This paper presents a new method for power factor correction with low cost drives. Power factor control is a major role in the improvement of power system stability. Many of the existing systems are expensive and difficult to manufacturer. Nowadays many of the converters have no input power factor correction circuits. The effect of power factor correction circuit is used to eliminate the harmonics present in the system. This type of power factor correction circuit is mostly used in the Switched Reluctance Motor controller drive. Fixed capacitor systems are always leading power factor under at any load conditions. This is unhealthy for installations of power system. The proposed embedded system drive is used to reduce the cost of the equipment and increase the efficiency of the system. Experimental results of the proposed systems are included. It is better choice for effective cost process and energy savings.
Further Study on the Conservation Laws of Energy-momentum Tensor Density for a Gravitational System  [PDF]
Chen Fang-Pei
Physics , 2008,
Abstract: The various methods to derive Einstein conservation laws and the relevant definitions of energy-momentum tensor density for gravitational fields are studied in greater detail. It is shown that these methods are all equivalent. The study on the identical and different characteristics between Lorentz and Levi-Civita conservation laws and Einstein conservation laws is thoroughly explored. Whether gravitational waves carry the energy-momentum is discussed and some new interpretations for the energy exchanges in the gravitational systems are given. The viewpoint that PSR1913 does not verify the gravitational radiation is confirmed.
The SNS Cryogenic Control System: Experiences in Collaboration  [PDF]
W. H. Strong,P. A. Gurd,J. D. Creel,B. S. Bevins
Physics , 2001,
Abstract: The cryogenic system for the Spallation Neutron Source (SNS) is designed by Jefferson Laboratory (JLab) personnel and is based on the existing JLab facility. Our task is to use the JLab control system design [2] as much as practical while remaining consistent with SNS control system standards. Some aspects of the systems are very similar, including equipment to be controlled, the need for PID loops and automatic sequences, and the use of EPICS. There are differences in device naming, system hardware, and software tools. The cryogenic system is the first SNS system to be developed using SNS standards. This paper reports on our experiences in integrating the new and the old.
Dissipative Particle Dynamics with Energy Conservation  [PDF]
J. Bonet Avalos,A. D. Mackie
Physics , 1997, DOI: 10.1209/epl/i1997-00436-6
Abstract: The stochastic differential equations for a model of dissipative particle dynamics with both total energy and total momentum conservation in the particle-particle interactions are presented. The corresponding Fokker-Planck equation for the evolution of the probability distribution for the system is deduced together with the corresponding fluctuation-dissipation theorems ensuring that the ab initio chosen equilibrium probability distribution for the relevant variables is a stationary solution. When energy conservation is included, the system can sustain temperature gradients and heat flow can be modeled.
钢铁企业节能减排考核评价体系及应用
Energy Conservation and Emission Reduction of Iron and Steel Industry Evaluation Index System and Its Application
 [PDF]

刘影, 段蒙, 赵云杰
Sustainable Development (SD) , 2016, DOI: 10.12677/SD.2016.61002
Abstract:
依据当前我国钢铁企业节能减排工作的要求和研究现状,从原料及工序能耗、能源消费结构、技术工艺、资源效率和能源管理5个维度建立了钢铁企业节能减排考核评价指标体系。在此基础上,运用层次分析法确定各评价指标的权重,并依据模糊综合评价法计算钢铁企业节能减排工作得分,从而综合评价节能减排工作的优劣,最后以某钢铁企业为例进行实例研究,综合评价其节能减排工作,验证了模糊综合层次法在钢铁企业节能减排评价中的可行性。评价结果有助于钢铁企业及其他行业认清节能减排中存在的薄弱环节,为钢铁企业及相关企业提升节能减排工作效率提供科学的决策依据。
On the basis of China iron and steel enterprises’ current requirements and research status in energy conservation and emissions reduction, the evaluation index system of energy conservation and emissions reduction for iron and steel enterprises based on five dimensions of energy consumption of raw materials and process, energy consumption structure, technical process, resource efficiency and energy management is established. Based on the information stated above, the method of AHP is applied to determine the weight of each index, and AHP-fuzzy comprehensive evaluation method is used to get scores of iron and steel enterprises’ energy conservation and emissions reduction in order to judge the advantages and disadvantages of the energy conservation and emissions reduction. Finally, a case is used to confirm the availability of AHP-fuzzy comprehensive evaluation method in the evaluation of energy conservation and emissions reduction for iron and steel industry through the evaluation of its energy conservation and emissions reduction work. The results may help to identify weaknesses existing in energy conservation and emissions reduction and provide a scientific basis for improvement of energy conservation efficiency in iron and steel industry and other industries.
Application of an Optimum Design of Cooling Water System by Regeneration Concept and Pinch Technology for Water and Energy Conservation  [PDF]
A. Ataei,M.H. Panjeshahi,R. Parand,N. Tahouni
Journal of Applied Sciences , 2009,
Abstract: In this study, using a combination of Pinch Technology and Mathematical Programming, a new technique is presented in order to grass-root design for a cooling water system to achieve minimum total annual cost. The presented technique is further improved by using patterns from the concept of regeneration recycling in water systems; in a sense that cooling water is regenerated locally by an air cooler. Moreover, in the proposed method, optimum design of cooling tower has been achieved through a mathematical model. Related coding in MATLAB version 7.3 was used for the illustrative example to get optimal values in the proposed cooling water design method computations. The result of the recently introduced design methodology was compared with the conventional and Kim and Smith design methods. The outcomes indicate that by using this new design method, more water and energy can be saved and a lower level of total annual cost can be reached.
Cryogenic System for PKU-FEL  [PDF]
Lianyou Xiong, Nan Peng, Wenhai Lu, Liqiang Liu, Xiaojun Liu, Jing Li, Liya Ma, Bing Dong, Yongcheng Jiang, Jiancheng Tang, Liang Zhang
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.46A001
Abstract:

PKU-FEL based on superconducting (SC) accelerator facility is under construction at PekingUniversity. It will run in IR (5 - 10 μm) and THz (100 - 3000 μm) region as an ideal experimental FEL platform for universities. The SC accelerator facility is composed of a DC-SC injector and a 1.3-GHz 2 × 9-cell SC accelerator. In order to better the performance, the injector and the accelerator are bath-cooled by 2 K super fluid helium in cryostats. A 2 K cryogenic system has been designed, constructed and assembled.

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