Recycling value of building materials in building assessment systems

The selection of green building materials and products is by far the most controversial task in sustainable construction. Determining the merits of building materials and products in terms of their recycling value, which seems to be a simple matter, is a very controversial topic in building assessment systems. This paper suggests a method to assess energy savings by recycling building materials, which can be a potential indicator of recycling worth. The method takes account of material selection, construction and deconstruction technologies, and the frequency of recycling. The result of this study can be used in assessment tools as a factor separate from the embodied energy. Since embodied energy affects the potential recycling energy, another factor is defined, based on these two factors, in order to make it possible to compare and select materials correctly, based on their embodied energy and recycling potential.     

A New Fracture Toughness Test Covering Mixed-Mode Conditions and Positive and Negative <Emphasis Type="Italic">T</Emphasis>-Stresses

It is known that sign of T-stress in cracked specimens affects fracture toughness under mixed mode conditions. We suggest a new test involving an inclined edge cracked semi circular specimen subjected to asymmetric three-point bend loading (IASCB specimen) that covers a broad range of modes I and II SIFs and T-stress values. It can provide both positive and negative T-stresses. This is illustrated by FEM computations.     

The blue garden: coastal infrastructure as ecologically enhanced wave-scapes

Hard coastal infrastructure such as breakwaters and seawalls are built according to engineering parameters of structural performance and cost efficiency. Especially in urban settings, they conflict with the diverse needs and values of other users and stakeholders, such as sustaining coastal ecosystem biodiversity and providing the public with open, accessible spaces for socialisation and recreation. The presented research explores how the discipline of landscape design can contribute to their evolution. Building on recent precedents in developing multi-functional, ecologically enhanced seawalls, it proposes the concept of the blue garden, and explores two of its key features: bio-engineering the form and materiality of seawalls to enhance their performance as ecosystem service providers; and utilising computational fluid dynamics to poetically shape sea waves as a visual, aural and tactile landscape material to enhance its social and experiential value. It concludes with a pilot study that implements these principles for a specific urban site.     

毫米波雷达导引头技术研究

毫米波雷达导引头是毫米波精确制导技术的重要组成部分.首先介绍了对导引头的基本要求,然后详细介绍了毫米波雷达导引头的工作原理、关键技术、工作模式、主要特点以及典型应用,最后分析了毫米波导引头的发展方向.     

珠宝平面广告设计的探索和研究

从平面广告的构成元素出发,对平面知识在珠宝设计中的运用进行分析,研究珠宝平面广告的设计方法。     

加氢反应器用2.25Cr-1Mo-0.25V钢锻件的持久性能

研究了高温持久对2.25Cr-1Mo-0.25V钢断口及显微组织的影响。对热处理态试样的常温、高温及相同温度、不同载荷下的高温持久强度进行分析,并通过扫描电镜(SEM)对持久试样的断口及微观组织进行观察。结果表明,随着加载应力的增加,持久时间显著降低,持久试样断裂后,断口形貌的韧窝中有富Mo析出相,且随着持久断裂时间的延长,析出相中Mo元素含量逐渐增多。     

Power Sharing Improvement in Standalone Microgrids with Decentralized Control Strategy

Abstract—This article proposes a method that enables ideal sharing of reactive power among converter-based micro-sources in a microgrid with a decentralized control strategy. Power sharing must be properly performed among micro-sources to avoid circulating currents or overloading. Using conventional droop characteristics to achieve power sharing is not satisfactory, as system asymmetry will greatly impact the quality of sharing. In the proposed method, droop characteristic parameters are modified upon a change in system operating point such that ideal sharing takes place after the modification process. Simulation results are presented to show the validity of analysis.