Thermal Performance Analysis of Highly Reflective Coating on Residences in Hot and Arid Climates

A 1-D transient model (RESHEAT), developed by the writers, was used to study the thermal performance of a highly reflective paint applied sequentially to the outer walls and roof of a simulated residence in a hot and arid region of the southwestern United States. The model uses climatological inputs from a file that includes hourly data on ambient temperatures, insolation, cloud cover, and so on, at the particular location. The model focuses particularly on the potential cooling load reduction due to the reduced heat pickup from the inside attic surfaces to the outer surfaces of the supply duct. This simulation showed that a reduction of 33.6% (cooling load) on the average is achieved over the base case where no reflective paint is used when the outer surface of the roof and walls are painted. Alternatively, only a 11% reduction would be achieved if the reflective paint is applied only to the roof. Savings of $42 per month are conservatively estimated from calculations made when applying this technology to a typical residence (roof and walls) equipped with a 4 ton refrigeration unit in the Southwest.     

Network and device-level impacts: performance and reliability of active I/O storage systems

Distributed active storage architectures are designed to offload user-level processing to the peripheral from the host servers. In this paper, we report preliminary investigation on performance and fault recovery designs, as impacted by emerging storage interconnect protocols and state-of-the-art storage devices. Empirical results obtained using validated device-level and interconnect data demonstrate the significance of the said parameters on the overall system performance and reliability.     

共沉淀法制备锰锌软磁铁氧体前躯体共沉过程中钙、镁深度脱除的热力学分析

通过对Fe(Ⅱ)-Mn(Ⅱ)-Zn(Ⅱ)-Ca(Ⅱ)-Mg(Ⅱ)-NH3-NH4HCO3-H2O体系的热力学分析，得到各金属离子浓度与pH的关系，从而确定共沉法制备锰锌软磁铁氧体前躯体共沉过程中钙、镁深度脱除的共沉区域。热力学分析结果表明，溶液中钙、镁的含量随着体系pH的增大而降低，在相同条件下镁的溶解度大于钙的溶解度。为减少进入共沉粉中的钙、镁含量，需要保证在铁、锰、锌共沉完全的基础上降低体系的pH。当溶液中[C]T=0．1mol／L，[N]T=1．0mol／L时，pH控制在6．23～6．50之间可以大大降低进入共沉粉中的钙、镁含量。确定共沉过程钙，镁深度脱除的共沉区域，对于生产高纯锰锌软磁铁氧体前躯体具有重要的指导意义。     

综合线损分析系统研究

描述了综合线损分析系统应该具有的主要功能和分析内容，介绍了系统实现中应该注意的几个问题、系统内容和实现方法。     

土石围堰三维有限元渗流分析及防渗措施研究

为了解决上游围堰防渗及绕坝渗漏问题,确定最优防渗方案,对炳灵水电站右岸松动体防渗帷幕的防渗方案进行了三维有限元渗流计算,并对右岸松动体帷幕的防渗范围和灌浆排数进行了敏感性分析。通过多种防渗方案的计算,对右岸松动体的防渗方案做了相应优化,建议了满足设计要求的防渗方案。     

Renewable energy systems: A societal and technological platform

Today, the analysis of renewable energy places the emphasis on the technological and economic attributes with social and environmental impact assessment providing for a rather static, narrow frame of analysis. The participation and response of social actors and other stakeholders is usually of a traditional type, with consultation documents and public meetings, collection of complaints and suggestion schemes. This often encourages parochialism and an over-concentration on relatively trivial issues. It is, therefore, imperative to establish a new participatory planning platform to incorporate the wider socio-economic aspects of renewable energy systems and to provide for an operational analytical decomposition of them. In this work the issue of decomposition analysis is clarified, and a new agenda for the societal and technological decomposition analysis of renewable energy systems is developed. A case study is disclosed to present the relevance of the established platform for integrated (renewable) energy systems planning. Innovative aspects comprise of the simultaneous inclusion of decision analysis and social acceptance methods and tools in concert with the related public participation techniques.     

Characterisation of inter-particle forces within agglomerated metallurgical powders

The strength of agglomerates of nickel flash furnace concentrate and dust was determined from experimental observations of agglomerates forming under controlled conditions, combined with mathematical equations from the literature. It was found that the agglomerates had a tensile strength ranging from 0.01 Pa to 38.7 Pa, while inter-particle forces ranged from 2.2 × 10^− 12 N to 1.5 × 10^− 10 N. These values were compared to the expected magnitude of van der Waals, electrostatic, magnetic and capillary forces within the agglomerates, and it was found that both electrostatic and van der Waals forces are likely to contribute to the cohesion of agglomerates, although sub-micron particles and the presence of sufficiently large asperities on the surface of particles limit the magnitude of van der Waals forces. Magnetic forces are large enough to contribute to the cohesion of dust agglomerates, which is in keeping with the high magnetite content of the recycle dust. It is postulated that electrostatic forces, acting over a longer range than van der Waals forces, may be responsible for initially bringing particles together. The methodology for determining inter-particle forces can be applied to the computer modelling of flash smelting systems, as well as other gas/particle systems such as fluidized beds.     

Studies of substrate specificities of lipases from different sources

Although lipases are widely applied in a wide variety of reactions, available information on the factors that are responsible for the substrate specificities of lipases from different sources is scarce. In this paper, nine lipase‐producing microorganism strains were isolated from oil‐containing samples. The properties of these enzymes, including pH optima, temperature optima, thermal stability, and pH stability, vary significantly with the different sources from which these lipases were isolated. The substrate specificities of the nine lipases, including fatty acid and positional specificities, were also studied. The fatty acid specificities of the nine lipases were observably different toward 15 substrates with different carbon chain lengths, different saturation degrees and different side chains. The lipases from S₃ Penicillium citrinum (PCL), MJ₁ Aspergillus niger (ANL), MJ₂ Aspergillus oryzae (AOL), YM Bacillus coughing (BCL), S₉ Geotrichum candidum (GCL), and S₁₁ Candida lypolytica (CLL) showed the strongest specificities to short‐chain esters, and the other lipases showed strong selectivity for medium‐ or long‐chain and branched esters. The positional specificities were examined by analyzing the hydrolytic products of triolein catalyzed by the nine lipases, using TLC. The lipases can be mainly classified into two groups by their specificities for the ester bond at position 2 of triglycerides; one group can selectively hydrolyze the ester bond at position 2 of the triglycerides, the other group cannot. All these nine lipases were divided into four groups by hierarchical clustering analysis on the basis of the results of fatty acid and positional specificities.     

Flammability ranking of foliage species by factor analysis of physical and chemical pyric properties

In this paper, factor analysis is introduced to evaluate the flammability of 55 foliage species that may be used in China for construction of the fuel break network of forest strips with lower flammability. Six pyric parameters, i.e. air dry moisture content, absolute dry moisture content, ignition point, ash content, caloric value and extractive content, are measured and used as variables for factor analysis. The covariance analysis shows that four principal factors can be extracted to reflect the flammability in different physical and chemical senses. In terms of the contributions of the four factors to the variances and the physical significance of the relevant parameters, the four factors are, respectively, termed as ‘flaming factor,’ ‘air dry factor,’ ‘ash factor’ and ‘absolute dry factor.’ The stability of the factor analysis method is examined by a different number of samples considered, and the variation degrees of the orderings indicate that the method has high reliability to measure the total flammability of foliage species. The results of the flammability evaluation are verified by comparison with the recommended tree species in the Chinese technology standard. Copyright © 2008 John Wiley & Sons, Ltd.