超高层建筑应急电源供电时间的研究

本文应用消防防火鉴定方法测算某项目中的超高层塔楼的疏散时间,从而对应急电源供电时间进行研究。通过对不同楼层高度疏散时间的对比,得到建筑物层数与应急电源供电时间的关系。并针对办公区楼层进行分析,得出办公区楼层的疏散时间与人员密度、建筑层数成正比关系。进而为超高层建筑应急电源供电时间的确定提供了依据,同时也为超高层建筑内人员密度的合理布局提供了参考。     

A model for predicting resuspension of Escherichia coli from streambed sediments

To improve the modeling of water quality in watersheds, a model is developed to predict resuspension of Escherichia coli from sediment beds in streams. The resuspension rate is expressed as the product of the concentration of E. coli attached to sediment particles and an erosion rate adapted from work on sediment transport. The model uses parameter values mostly taken from previous work, and it accounts for properties of the flow through the bottom shear stress and properties of the sediment through the critical shear stresses for cohesive and non-cohesive sediment. Predictions were compared to resuspension rates inferred from a steady mass balance applied to measurements at sixteen locations in a watershed. The model’s predictions matched the inferred rates well, especially when the diameter of particles to which E. coli attach was allowed to depend on the bottom shear stress. The model’s sensitivity to the parameters depends on the contributions of particle packing and binding effects of clay to the critical shear stress. For the current data set, the uncertainty in the predictions is controlled by the concentration of E. coli attached to sediment particles and the slope used to estimate the bottom shear stress.     

把握可持续发展主流——从政策到实践

0简介中国正处在发展的关键时期,是否按照西方依赖资源的高消耗道路走向繁荣?或者中国应该去寻找另一条通向繁荣的道路,而直接改为对环境影响较小的社会发展,从而避免对资源的过度开发?中国政府的目标是明确的。他们明白,如果中国继续保持繁荣增长,必须设法降低其对不断消耗自然资源的依赖和日益增加的环境影响。不幸     

Optimal placement of controllers for seismic structures

Active control devices can be implemented on seismic structures to reduce structural response from earthquakes. Certain locations of the structure are advantageous for placement of the controllers in the sense that these locations effectively reduce structural response while using the minimum control effort. A method is proposed which uses an empirical procedure to find the optimal locations by maximizing an optimal locations index. The method takes into consideration the modal responses and earthquake spectra for two different earthquake records. The proposed method is compared to two methods; in the first method a control energy performance index is minimized; the second method uses a minimum response performance index as the criterion. The proposed method is found to agree with the two alternative methods and saves computation time.     

The potential role of biofuels within the built environment

For most of man's life on earth the bulk of his energy needs have been met by the combustion of wood. The advent of the Industrial Revolution and the mining of coal in 18th century England led to dependence upon initially fossil, and later fossil and fissile, fuels within the industrialized nations and fuelwood consumption rapidly declined. Biomass (organic plant matter) has, however, continued to provide the main energy supply to the developing world.

With the present day necessity to conserve fossil fuel reserves, particularly oil, renewable biomass energy sources are' once again being examined with everincreasing interest, both in the West and in Communist bloc countries, as well as in the Third World. The potential contribution of biofuels (fuels derived from biomass) within both developed and developing nations is examined, particularly with respect to their utilization within the built environment.     

Measurement and exploration of individual beliefs about the consequences of building information modelling use

Information and communication technology (ICT) is becoming increasingly important in construction although the rate of adoption is considered slow and the industry faces specific implementation challenges. Mainstream information systems research has shown that individuals’ beliefs and expectations of the consequences of ICT use predict subsequent usage. We describe the development of scales to measure beliefs about the consequences of building information modelling (BIM) and their use in a survey of employees of a large construction contracting organization in the United Kingdom. Scales for performance expectancy, effort expectancy, social influence, facilitating conditions, compatibility, and attitude toward using technology were adapted from existing measures. In an analysis of responses from 762 construction employees the scales showed acceptable measurement properties. Expectations about the consequences of BIM use were broadly favourable although there is a need for more data for comparisons. The structure of the responses showed that expectations that BIM would enhance job performance were strongly related to expectations that BIM use was compatible with preferred and existing ways of working. Results also suggest that social influence is complex and may be multidimensional.     

A common network flow formulation for several civil engineering problems

This paper discusses a common network flow problem that arises in four areas of civil engineering. The problem is one of identifying arc flows that simultaneously satisfy the circuit and node law constraints for a given network. Applications and computational procedures in the areas of elastic structural analysis, hydraulic network analysis, traffic equilibrium and construction task scheduling are described. The interpretation of decision variables and mathematical functions will vary depending on the application, but the general priblem formulation and solution technique for each application remains essentially unchanged. Analogies between the different applications may enhance the conceptual understanding and intuition of engineers working in each area.     

马尼托瓦克移动式起重机专用KZ~(TM)100型缆绳

正在CONEXPO-CON/AGG 2014上,马尼托瓦克展示了配备KZT~(TM)100型缆绳的Grove RT770E型起重机。KZ~(TM)100型缆绳是首次专为移动式起重机设计的合成纤维卷扬缆绳,这项创新成果由马尼托瓦克携手合成纤维缆绳制造商Samson公司共同研制,由马尼托瓦克独家销售,从2014年下半年开始作为Grove系列越野起重机的选购件供应给客户。KZ~(TM)100型卷扬缆绳具有许多优点:质量比钢丝绳轻80%:采用转矩中性平衡结构,可消除负荷旋转和缆绳缠绕     

Architecture,Cigarettes AND THE Dispositif

This paper aims to explore the concept of the dispositif and develop arguments as to its value in reconceptualising the social function of architecture. The notion of the dispositif is derived from the writings of Michel Foucault and is explored in respect to the work of Gilles Deleuze and Félix Guattari. The notion of the dispositif of concern emerges from Foucault's concepts of an apparatus that manages relationships of power between different bodies and organisations. Foucault considers the dispositif to be at once object and apparatus – a dynamic tension that is well recognised by theorists of architecture as a potentially productive condition. It is upon this dynamic tension that the present paper will focus and present an exploration of Giuseppe Terragni's Casa del Fascio as an example of an architectural dispositif.