Risk assessment of airborne infectious diseases in aircraft cabins

Abstract Passengers in an aircraft cabin can have different risks of infection from airborne infectious diseases such as influenza, severe acute respiratory syndrome (SARS), and tuberculosis (TB) because of the non-uniform airflow in an aircraft cabin. The current investigation presents a comprehensive approach to assessing the spatial and temporal distributions of airborne infection risk in an aircraft cabin. A case of influenza outbreak was evaluated in a 4-h flight in a twin-aisle, fully occupied aircraft cabin with the index passenger seated at the center of the cabin. The approach considered the characteristics of the exhalation of the droplets carrying infectious agents from the index passenger, the dispersion of these droplets, and the inhalation of the droplets by susceptible passengers. Deterministic and probabilistic approaches were used to quantify the risks based on the amount of inhaled influenza virus RNA particles and quanta, respectively. The probabilistic approach indicated that the number of secondary infection cases can be reduced from 3 to 0 and 20 to 11, for influenza cases if N95 respirator masks are used by the passengers. The approach and methods developed can easily be implemented in other enclosed spaces such as buildings, trains, and buses to assess the infection risk. PRACTICAL IMPLICATIONS: Airborne infectious disease transmission could take place in enclosed environments such as buildings and transport vehicles. The infection risk is difficult to estimate, and very few mitigation methods are available. This study used a 4-h flight as an example in analyzing the infection risk from influenza and in mitigating the risk with an N95 mask. The results will be useful to the airline industry in providing necessary protection to passengers and crew, and the results can also be used for other enclosed spaces.     

蒙特利尔地下城的行人动态、布局和经济影响

尽管地下系统被广泛认为是蒙特利尔中央商务区的一个重要经济推动力，但是地下系统开发并没有一个总体规划或如何评估扩建提案的共识。为了给地下空间开发找到更系统的方法，本文调查了地下系统中行人流量水平所带来的经济影响，对以前的数据（Zacharias．2000）作了更新。文章结合了三套数据：综合行人流量调查数据与1996年和2003年更新后的房地产使用调查数据。这项调查显示出．在这种封闭的步行系统中，系统设计和由此产生的行人流量是如何与经济行为相关的．     

封闭阳台的折叠金属孔板遮阳设计

在夏热冬冷地区,活动外遮阳是使住宅封闭阳台成为气候缓冲空间的重要因素,应遵循四个基本原则:遮阳的可调节性;遮阳的通透性;遮阳的经济性;遮阳的美观性.通过比较当前活动外遮阳的不同形式,认为由金属孔板构成的推拉折叠遮阳形式能较好地满足住宅封闭阳台的遮阳要求,提出了封闭阳台折叠金属孔板遮阳设计的基本方法,并对该系统的遮阳散热、视线遮挡及美学特点进行了论述.     

福建传统土楼围合形态适应环境的不规则衍变

文章认为，福建传统土楼围合形态在适应环境的过程中，存在着二元矛盾的模糊行为。一方面存在着土楼围合的完形理想，另一方面，由于环境因素的微变化，围合的完形理想在现实当中常常被各种现实力量所解构。由此，也在历史上衍变出各种丰富多样的福建传统土楼围合形态。这些丰富多样的福建传统土楼围合形态，由于其记录着复杂的土楼对环境的生态适应信息，也具有较高的生态文化保护和旅游教育价值。     

An evaluation of energy response and cumulative plastic rotation demand in steel moment‐resisting frames through dynamic/static pushover analyses

In the energy‐based design approach, the seismic design is performed through the balancing of the energy input and the energy dissipation of the structure. The energy dissipation is represented by the hysteretic energy dissipation capacity defined as the total area enclosed in the force–deformation curves under cyclic loading. Thus, the energy‐based design approach considers the cumulative effect of the seismic loading of the structure. The cumulative damage in the structural members can be expressed in terms of cumulative plastic rotation (CPR). The CPR capacity plays an important role in determining the hysteretic energy dissipation capacity of a steel moment connection. This study investigated the energy response and the CPR capacity and demand through dynamic pushover analyses on steel moment‐resisting frames. The results were compared with the ones obtained from the pushover analysis. Copyright © 2008 John Wiley & Sons, Ltd.     

封闭住区的负效应及解决方法

当前我国建设的大量住区都是封闭住区,这在城市人居环境、城市交通、城市空间形态和土地利用效率等方面带来诸多负面影响。依据城市规划和建筑设计的相关理论,结合工程实例提出采用开放式住区,围合式组团的思路来满足城市和住区对空间形态的不同要求;由此得出解决封闭住区负效应的有效方案。     

沉积层序对谷地场地地震反应的影响-SH波入射

采用一种多域间接边界元方法,求解了层状半空间中多层沉积谷地对平面SH波的放大效应问题。该方法将含有多层沉积的层状半空间分解为开口层状半无限空间域和多个沉积层闭合域,进而通过求解层状半空间中斜线均布荷载动力格林函数来模拟开口域内的散射波场,通过求解全空间中均布荷载动力格林函数来模拟各闭合域的散射波场。方法充分发挥半空间格林函数和全空间格林函数在构造开口半无限空间域和闭合域内散射波场方面的优势,具有灵活性强和精度高的优点。文中验证了方法的正确性,并以正常沉积、软夹层沉积和逆序沉积为例进行了数值计算分析,研究了沉积层序对谷地附近地面运动的影响。数值结果表明,沉积层逆序排列时,低波速层对中高频地震动均有很好的“隔震”效果;沉积层序对地面运动的固有频率和卓越频率均有着显著的影响;沉积序列的改变会导致沉积动力特性的改变,进而会影响到沉积谷地与层状场地的动力相互作用机制。     

受限空间油池火燃烧特性的实验研究

通过理论分析和实验研究的方法来研究油池火在受限空间的燃烧特性。初步总结了受限空间油池火燃烧的特性及其规律，给出了在实验条件下油池火在受限空间和开放空间燃烧速率以及燃料吸收热量的差异。讨论了通风条件和油池燃烧面积以及通风口高度对于燃料的燃烧速率的影响，初步确定了受限空间中油池火燃烧速率与油池面积、通风因子的关系。     

The influence of solubility effects on the pressure increase during deformation of closed thin-walled structures

In structures with an internal volume, the enclosed gas can significantly contribute to the strength and stiffness. If this enclosed volume also contains a fluid then an exchange of components between the gas and fluid can take place. The present paper describes these solubility effects and presents a method to account for the solubility effect in structural analyses. The method described has been studied on a typical packaging problem, namely a closed filled bottle under vertical compression. The numerical studies were validated by experiments.     

Identification of contaminant sources in enclosed spaces by a single sensor

To protect occupants from infectious diseases or possible chemical/biological agents released by a terrorist in an enclosed space, such as an airliner cabin, it is critical to identify gaseous contaminant source locations and strengths. This paper identified the source locations and strengths by solving inverse contaminant transport with the quasi-reversibility (QR) and pseudo-reversibility (PR) methods. The QR method replaces the second-order diffusion term in the contaminant transport equation with a fourth-order stabilization term. By using the airflow pattern calculated by computational fluid dynamics (CFD) and the time when the peak contaminant concentration was measured by a sensor in downstream, the QR method solves the backward probability density function (PDF) of contaminant source location. The PR method reverses the airflow calculated by CFD and solves the PDF in the same manner as the QR method. The position with the highest PDF is the location of the contaminant source. The source strength can be further determined by scaling the nominal contaminant concentration computed by CFD with the concentration measured by the sensor. By using a two-dimensional and a three-dimensional aircraft cabin as examples of enclosed spaces, the two methods can identify contaminant source locations and strengths in the cabins if the sensors are placed in the downstream location of the sources. The QR method performed slightly better than the PR method but with a longer computing time. PRACTICAL IMPLICATIONS: The paper presents a method that can be used to find a gaseous contaminant source location and determine its strength in enclosed spaces with the data of contaminant concentration measured by one sensor. The method can be a very useful tool to find where, what, and how the contamination has happened. The method is also useful for optimally placing sensors in enclosed spaces. The results can be applied to develop appropriate measures to protect occupants in enclosed environments from infectious diseases or chemical/biological warfare agents released by a terrorist.     

客属围屋 唯我侨乡

在粤东梅州客家地区分布着大量的围屋式民居,明朝成化年间开基的南口镇的侨乡村,在1.5km2的范围内就分布着31座清末民初兴建的百年客家围屋,是围屋聚落最密集的乡村之一。同时这里建筑类型丰富,有民居、祠堂、学塾、庙宇等,民居建筑中又有围龙屋、杠横屋、华侨大屋、别墅洋楼等多种形式。其建筑布局和营造在节约土地、灾害防御、建筑功能和空间营造等方面均体现处独到的科学和艺术性,值得我们深入研究、借鉴和保护利用。     

严寒地区电站锅炉房的通风与供暖防冻设计

严寒地区一般在电站锅炉周围采用复合型保温压型钢板进行封闭,形成封闭围护结构,称为紧身封闭锅炉房;认为紧身封闭锅炉房冬季运行底层温度偏低、管道冻裂的主要原因是热压作用下的大量冷风入侵,指出在设计过程中要综合考虑锅炉房的夏季全面通风与底层冬季供暖防冻,锅炉房运转层平台的钢格栅、开口、楼梯间等造成运转层上下部空气流通部位的尺寸需要合理控制,并简要描述了冬季循环通风系统的设计与应用。     

Water quality and accelerated winter growth of European catfish using an enclosed recirculating system

Aquaculture of the European catfish Silurus glanis is impeded by the slow rate of growth at ambient water temperatures below 10°C, which are encountered during the winter months in many regions of Europe (such as central France). In an effort to increase water temperatures over this period, fish were held in an enclosed housing where the water quality was maintained using a low‐cost treatment plant. For comparison, some fish were held in a separate system that was not enclosed and where water treatment took place in an adjacent earth‐lined pond. Both systems were able to maintain good water quality during the winter months but the recirculating system achieved significantly higher water temperatures and rates of fish growth.     

从中国传统聚落空间看门禁社区的形态渊源 *

门禁社区在全球蔓延的现象已 经引起了学术界的广泛关注。对于门禁社 区在中国的大量兴起,国内外学者从城市 规划学、城市社会学、政治经济学、心理 学等不同角度进行了研究与诠释。文章对 不同时期、级别和区域聚落的封闭现象 进行了研究,并试图通过对传统聚落与 门禁社区在物质形态、组织管理模式及 与外界关系等方面进行比较,研究门禁 社区与中国传统聚落的关系。通过分析, 文章认为中国门禁社区是中国传统封闭 居住模型在新时代的延续与演变。     

Office layout affecting privacy,interaction, and acoustic quality in LEED-certified buildings

The study investigated differences in worker satisfaction and perceived job performance regarding privacy, interaction, and acoustic quality issues in personal workspaces between five office types in LEED-certified buildings. It finds that people in high cubicles showed significantly lower satisfaction and job performance in relation to visual privacy and interaction with co-workers than both enclosed private and enclosed shared office types. They also showed significantly lower satisfaction with noise level and sound privacy and lower job performance perceived by acoustic quality than enclosed private, enclosed shared, and bullpen types. The bullpen type, open-plan office without partitions, presented significantly higher satisfaction with noise level and higher performance perceived by acoustic quality than both high and low cubicles. Considering the bullpen type also showed higher satisfaction with sound privacy than the high cubicle type, high partitions don't seem to contribute to creating workspaces where people can have a secure conversation. The bullpen type didn't show any difference from the enclosed shared type in all privacy, interaction, and acoustic quality questions, indicating it may be a good option for a small office space instead of the enclosed shared type.     

封闭阳台的折叠金属孔板遮阳设计

在夏热冬冷地区,活动外遮阳是使住宅封闭阳台成为气候缓冲空间的重要因素,应遵循四个基本原则：遮阳的可调节性;遮阳的通透性;遮阳的经济性;遮阳的美观性。通过比较当前活动外遮阳的不同形式,认为由金属孔板构成的推拉折叠遮阳形式能较好地满足住宅封闭阳台的遮阳要求,提出了封闭阳台折叠金属孔板遮阳设计的基本方法,并对该系统的遮阳散热、视线遮挡及美学特点进行了论述。     

用外包钢筋混凝土法加固RC柱性能的试验研究

通过模型试验研究,重点讨论了初始应力水平指标对加固柱性能的影响;提出了考虑应力水平指标和外包混凝土对核心混凝土约束作用的承载力计算方法,计算结果与试验结果吻合较好。     

钢筋混凝土围套加固轴心受压砖柱若干问题

讨论了钢筋混凝土围套外包加固砖柱在轴心受压时的受力特点、极限状态及截面承载力计算等几个问题,供加固改造时参考。     

封闭式冷轧机间通风问题的探讨

介绍了宝钢封闭式冷轧车间通风系统的设计概况及日本不锈钢厂封闭车间通风系统的运行效果,提出了此类系统的设计方法和应注意的问题。     

上海市临港围合式住宅规划实践探索与对策建议

上海临港限价商品房项目为上海市2011年推进的围合式住宅规划试点项目,采用“总体控制先行、规划制定导则、多家设计参与”的组织模式,从规划设计到项目实施整个过程中对围合式住宅开展了深入研究和实践探索。依托该项目实践,总结围合式住宅的设计构思和具体做法,并针对后期项目实施中围合式住宅遇到的朝向、日照、物业管理、安全技术防范以及市场接受度等问题展开具体分析和方向性的对策建议,为围合式住宅的规划设计与实施提供借鉴。