Optimal configuration analysis for a campus microgrid—a case study

The foremost issues of 21st century are challenging demand of electrical energy and to control the emission of Green House Gases (GHG) emissions. Renewable energy resources based sustainable microgrid emerges as one of the best feasible solution for future energy demand while considering zero carbon emission, fossil fuel independency, and enhanced reliability. In this paper, optimization and implementation of institutional based sustainable microgrid are discussed based on cost analysis, carbon emission, and availability of energy resources. Various microgrid topologies are considered for addressing the most ideal solution. The metrological data such as irradiance is acquired from solar satellite data of NASA (National Aero Space Agency) while the data for wind speed is taken from synergy enviro engineer’s site. HOMER® simulation tool is used for modelling and optimization purpose.     

Optimal configuration analysis for a campus microgrid—a case study

The foremost issues of 21st century are challenging demand of electrical energy and to control the emission of Green House Gases (GHG) emissions. Renewable energy resources based sustainable microgrid emerges as one of the best feasible solution for future energy demand while considering zero carbon emission, fossil fuel independency, and enhanced reliability. In this paper, optimization and implementation of institutional based sustainable microgrid are discussed based on cost analysis, carbon emission, and availability of energy resources. Various microgrid topologies are considered for addressing the most ideal solution. The metrological data such as irradiance is acquired from solar satellite data of NASA (National Aero Space Agency) while the data for wind speed is taken from synergy enviro engineer’s site. HOMER® simulation tool is used for modelling and optimization purpose.     

Dynamic MR imaging of a minipig’s knee using a high-density multi-channel receive array and a movement device

Object

To construct an optimised, high-density receive array and a movement device to achieve dynamic imaging of the knee in orthopedic large animal models (e.g., minipigs) at 1.5 T.

Materials and methods

A 13-channel RF receive array was constructed, and the crucial choice of the array element size (based on considerations like region of interest, geometry of the minipig’s knee, achievable signal-to-noise ratio, applicability of parallel imaging, etc.) was determined using the Q factors of loops with different sizes. A special movement device was constructed to guide and produce a reproducible motion of the minipig’s knee during acquisition.

Results

The constructed array was electrically characterised and the reproducibility of the cyclic motion was validated. Snapshots of dynamic in vivo images taken at a temporal resolution (308 ms) are presented. Some of the fine internal structures within the minipig’s knee, like cruciate ligaments, are traced in the snapshots.

Conclusion

This study is a step towards making dynamic imaging which can give additional information about joint injuries when static MRI is not able to give sufficient information, a routine clinical application. There, the combination of a high-density receive array and a movement device will be highly helpful in the diagnosis and therapy monitoring of knee injuries in the future.     

Develop a wireless measurement system

Overview Wireless communication offers many benefits for measurement applications, including lower wiring costs, simple data transfer, and remote monitoring capabilities. There are several ways to take advantage of wireless communication with National Instruments measurement hardware and LabVIEW, as this document details     

70 a使用寿命的线缆

正随着社会经济的快速发展,房地产开发和危房改造正如火如荼地进行。这是我国建筑用线缆发展的机遇,但同时也是挑战。传统建筑用线缆常因过负荷或过电压引发漏电、火灾等安全事故。为了避免此类事故的发生,住建部于2014年发布的JG/T 441—2014《额定电压450 V/750 V及以下双层共挤绝缘辐照交联无卤低烟阻燃电线》和JG/T 442—2014《额定电压0.6 kV/1 kV双层共     

谈谈制冷剂R134a

自1993年关于保护臭氧层的《国家方案》公布以后,新型无公害制冷剂R134a作为R12的替代品得到了进一步研究和开发,并逐步应用于绿色环保冰箱中。 R134a属于氢氟化碳化合物。化学名称为四氟乙烷。它与R12相比具有较相似的热物理性质,而且消耗臭氧潜能ODP和温室效应潜能GWP均很低(见表1,R134a与R12的基本物性比较汇总表),并且基本上无毒性,特别是在汽车空调上的应用已十分成功。此外,在用户普遍关心的主要指标即安全性、来源可靠性和成本方面都具有较强的竞争力,因此,它被大多数厂商普遍看好。     

Effect of Channel Geometry and Properties of a Vapor–Gas Mixture on Volume Condensation in a Flow through a Nozzle

A method of direct numerical solution of the kinetic equation for the droplet size distribution function was used for the numerical investigation of volume condensation in a supersonic vapor–gas flow. Distributions of temperature for the gas phase and droplets, degree of supersaturation, pressure, fraction of droplets by weight, the number of droplets per unit mass, and of the nucleation rate along the channel were determined. The influence of nozzle geometry, mixture composition, and temperature dependence of the mixture properties on the investigated process was evaluated. It has been found that the nozzle divergence angle determines the vapor–gas mixture expansion rate: an increase in the divergence angle enhances the temperature decrease rate and the supersaturation degree raise rate. With an increase or decrease in the partial pressure of incondensable gas, the droplet temperature approaches the gas phase temperature or the saturation temperature at the partial gas pressure, respectively. A considerable effect of the temperature dependence of the liquid surface tension and properties on gas phase parameters and the integral characteristics of condensation aerosol was revealed. However, the difference in results obtained with or without considering the temperature dependence of evaporation heat is negligible. The predictions are compared with experimental data of other investigations for two mixtures: a mixture of heavy water vapor with nitrogen (incondensable gas) or n-nonane vapor with nitrogen. The predictions agree quite well qualitatively and quantitatively with the experiment. The comparison of the predictions with numerical results from other publications obtained using the method of moments demonstrates the usefulness of the direct numerical solution method and the method of moments in a wide range of input data.     

Is Electricity a Right?

It doesn’t have to be. It can be treated as a commodity so long as consumers face the volatility inherent in wholesale prices, the obligation to serve is no longer the sole domain of third parties, and barriers to entry are minimized. As long as electricity continues to be treated as a right, though, customers and politicians should know it involves significant (stranded) costs in both generation and transmission.     

R134a与R600a制冷剂冰箱设计及工艺技术研究

介绍了R134a与R600a两种绿色制冷剂的特性，并进行了比较。在此基础上，对冰箱设计及工艺技术研究进行了分析。     

ISA100.11a标准概述

该ISA100.11a标准着重于现场设备在过程制造中的应用。ISA100.11a已定义了自动化应用类,而不仅限于在过程安全和低延迟的应用。该标准定义了现场设备和网络的多种角色,但是没有限制这些专用设备的角色(见图)。统管理和安全功能基于OSI模型的协议栈(物理层、数据链路层、网络层、传输层和应用层)。它不指定任何骨干网或回程网络,也没有指定任何更高级别的自动化应用。它假定网关、系统管理和安全     

国内制冷企业替代应慎重选择HCFC-134a及R600a

回顾几年来关于ＣＦＣｓ的替代过程，到今天已卓有成效，各类替代工质及相关技术已成为商业技术，得到了广泛的应用。其整个过程，体现了人类对自身环境前所未有的广泛关注，对人类社会的可持续发展的影响也是巨大的。可以说，人类在替代ＣＦＣｓ的过程中其思路是这样的。首先是因为ＣＦＣｓ物质中的ＣＬ原子破坏臭氧层，于是去寻不含或含不容易分解ＣＬ原子的物质，经试验以后，发现ＨＣＦＣ－１３４ａ的热物理性与ＣＦＣ－１２比较接近，于是加强了对该物质的研究，经几年的研究，发现寻找替代物的根本原因不是表面上的保护臭氧层，而是深…     

R600a压缩机优化设计探讨

１引言压缩机是冰箱的心脏,随着人们对冰箱要求的提高,压缩机的节能、低噪、环保必然成为各冰箱厂家关注的焦点。本文介绍的是冰箱用全封闭型活塞式压缩机在降低能耗和噪声方面所进行有益的改进。加西贝拉公司自１９９６年起开始就压缩机的能耗、噪声、环保问题进行了研究。通过近年来的探索和实践,在此方面已积累了一些经验,希望与有关专家及同行共同切磋。２对制冷工质的选择随着国际上ＣＦＣ替代技术的发展,我公司从１９９６年起开始Ｒ１２的替代工作。由于Ｒ１３４ａ的ＯＤＰ值为０,ＧＷＰ值为１０００－２９００,Ｒ１３４ａ与矿…     

VSP—a quantum-electronic simulation framework

The Vienna Schrödinger-Poisson (VSP) simulation framework for quantum-electronic engineering applications is presented. It is an extensive software tool that includes models for band structure calculation, self-consistent carrier concentrations including strain, mobility, and transport in transistors and heterostructure devices. The basic physical models are described. Through flexible combination of basic models sophisticated simulation setups for particular problems are feasible. The numerical tools, methods and libraries are presented. A layered software design allows VSP’s existing components such as models and solvers to be combined in a multitude of ways, and new components to be added easily. The design principles of the software are explained. Software abstraction is divided into the data, modeling and algebraic level resulting in a flexible physical modeling tool. The simulator’s capabilities are demonstrated with real-world simulation examples of tri-gate and nanoscale planar transistors, quantum dots, resonant tunneling diodes, and quantum cascade detectors.     

国内制冷企业替化应慎重选择HCFC-134a及R600a

回顾几年来关于CFCs的替代过程,到今天已卓有成效,各类替代工质及相关技术已成为商业技术,得到了广泛的应用.其整个过程,体现了人类对自身环境前所未有的广泛关注,对人类社会的可持续发展的影响也是巨大的.     

Nuclear industrv experiences a new dawn

Nuclear industry experiences a new dawnChina's nuclear industry,after three year's continuous decline in itsrealized profits,has been seeing a new dawn recently.China's more than200 nuclear enterprises,both civilian and military,has seen an increase ofmore than 30 per cent in profits in 1989 over the previous year.In 1990,special attention will have to be paid to nuclear science andtechnology and management.The first phase of Qinshan Nuclear PowerStation in Zhejiang Province,installing one set of 300 MWe nuclear powerunit,will have to enter its overall debugging period by the end of March,1990,and generate electricity by the end of 1990.While the overall design     

正确维修HFC134a电冰箱

用HFC134a制冷剂替代CFC12(R-12)的应用技术日趋成熟。这类电冰箱从箱体结构,主要组成部件、制冷原理、制冷系统、电气系统与CFC12电冰箱基本相同,因而常见故障表现特征与维修技术方面具有很多的相同或相似之处,但是也存在一些差异,主要是制冷剂特性所引起的有关材料及维修工艺不同。下边介绍如何提高这类冰箱的检修质量及正确维修应注意的一些问题。 1.压缩机不能互换 HFC134a,又名四氟乙烷,热物理性能与CFC12十分接近,不可燃,无毒、无味、使用安全。与CFC12比较,HFC134a蒸发压力较低,冷     

Set up of a Screen-Printing Procedure for the Production of a β Alumina-Based Gas Sensor*

A gas sensor based on a -alumina thick film was recently developed on a laboratory scale. This sensor can be successfully used for selective detection of CO and NO_x, resulting from an appropriate choice of the working temperature of the sensing element. This paper deals with the approach of the industrial transfer of the sensor prototype, mainly concerning the scale-up of the screen-printing procedure from a hand-operated apparatus to an industrial production machine. Many parameters were already investigated during the laboratory development, namely the ink composition in terms of organic/inorganic component ratio, the type and amount of the liquid dispersant and rheological agent, the composition and softening temperature of the binder, the -alumina/binder weight ratio. During the industrial transfer, some other parameters must be considered, such as the particle size distribution of the ceramic components of the ink, the influence of the mesh number of the screen fabric on the surface texture of the -alumina film, the viscosity performances of the ink as a function of the applied shear rate and ageing. A common commercial metallic paste was also used as reference for optimizing the characteristics of the -alumina based ink.     

Exploring a reversible NOR from a 4 × 4 modified Fredkin gate and its optical mapping using a LiNbO3-based MZI

Journal of Computational Electronics - The extensive search for the implementation of reversible logic using emerging technologies has paved the way for the rise of optical computing. The...