Survey of 1012 moldy dwellings by culture fungal analysis: Threshold proposal for asthmatic patient management

Different countries have tried to define guidelines to quantify what levels of fungi are considered as inappropriate for housing. This retrospective study analyzes indoor fungi by cultures of airborne samples from 1012 dwellings. Altogether, 908 patients suffering from rhinitis, conjunctivitis, and asthma were compared to 104 controls free of allergies. Portuguese decree law no 118/2013 (PDL118), ANSES (a French environmental and health agency) recommendations, and health regulations of Besançon University Hospital were applied to determine the rates of non‐conforming dwellings, which were respectively 55.2%, 5.2%, and 19%. Environmental microbiological results and medical data were compared. The whole number of colonies per cubic meter of air was correlated with asthma (P < 0.001) and rhinitis (P = 0.002). Sixty‐seven genera and species were detected in bedrooms. Asthma was correlated to Aspergillus versicolor (P = 0.004) and Cladosporium spp. (P = 0.02). Thresholds of 300 cfu/m³ for A. versicolor or 495 cfu/m³ for Cladosporium spp. are able to discriminate 90% of the asthmatic dwellings. We propose a new protocol to obtain an optimal cost for indoor fungi surveys, excluding surface analyses, and a new guideline to interpret the results based on >1000 cfu/m³ of whole colonies and/or above threshold levels for A. versicolor or Cladosporium spp.     

航班运行系统仿真建模分析

为研究航班计划的运行效率及其在突发扰动下的鲁棒性,将计算机仿真技术应用于航空运输系统,结合分类与航班过站时间的Logistic分布拟合等,通过模拟飞机起飞/降落、滑入/滑出、过站保障和航段飞行等运行过程,建立了含有118个国内主要机场的航班运行仿真模型,在Flexsim平台上实现了大型航空公司航班计划运行仿真.此模型可以模拟正常和流控等不正常情况下的航班运行,并输出延误时间、正常率、飞机利用率、缓冲时隙等评估指标.案例分析结果表明:模型较准确地模拟了航空公司航班的实际运行情况.在正常情况下,对输出指标分析可以确定航班计划中导致延误的重点环节;在流控情况下,可以发现航班延误的范围呈扩散趋势,传播方向沿航班串向下,且延误时间逐渐减少,受直接影响航班过站时间大幅增加,受牵连影响航班过站时间减少.     

Home energy efficiency and radon: An observational study

Exposure to radon gas is the second leading cause of lung cancer worldwide behind smoking. Changing the energy characteristics of a dwelling can influence both its thermal and ventilative properties, which can affect indoor air quality. This study uses radon measurements made in 470 689 UK homes between 1980 and 2015, linked to dwelling information contained within the Home Energy Efficiency Database (HEED). The linked dataset, the largest of its kind, was used to analyze the association of housing and energy performance characteristics with indoor radon concentrations in the UK. The findings show that energy efficiency measures that increase the airtightness of properties are observed to have an adverse association with indoor radon levels. Homes with double glazing installed had radon measurements with a significantly higher geometric mean, 67% (95% CI: 44, 89) greater than those without a recorded fabric retrofit. Those with loft insulation (47%, 95% CI: 26, 69) and wall insulation (32%, 95% CI: 11, 53) were also found to have higher radon readings. Improving the energy performance of the UK's housing stock is vital in meeting carbon emission reduction targets. However, compromising indoor air quality must be avoided through careful assessment and implementation practices.     

Modeling occupant behavior of the manual control of windows in residential buildings

Window opening and closing is the most preferred behavior for occupants to control their indoor environment in homes. This study aims to identify driving forces for window opening and closing behavior in the home. The additional field survey was carried out for the cooling period after following the previous study. The state of windows and environmental variables for outdoor and indoor were continuously monitored in 23 sample homes over one year. The monitored data provide evidence that there is a statistically significant relationship between window opening behavior and outdoor temperature. The behavior of the occupant's manual control of windows can be described by seasonal effects, occupancy, and time of day. Indoor stimuli, such as such as temperature, humidity, and CO₂, can better account for the window opening behavior than can outdoor stimuli. There are clear differences in driving variables between window opening and closing behavior. The closing behavior is better described when the outdoor and indoor variables are combined. Finally, multivariate logistic regression models were developed to predict typical patterns of window opening and closing as a function of indoor and outdoor variables.     

掘进工作面瓦斯分级治理的技术研究

余吾煤业公司作为高瓦斯矿井,瓦斯吸附能力强,属低透气性难抽放煤层。矿井目前处于新旧采区重叠期、瓦斯含量双向变化重叠期,需要立足当前、分类施策,提升采掘效率。为进一步规范掘进工作面瓦斯治理,建立规范的瓦斯治理程序,介绍了掘进工作面瓦斯分级治理相关措施,确保掘进工作面安全生产有序进行。     

浅谈军用空调制冷系统管路抗振动、抗冲击工艺措施

本文介绍了军用空调制冷系统管路存在的常见管路断裂问题,并对系统管路出现的断裂缺陷进行了详细的原因分析,由此提出解决该问题的相应工艺措施。将该工艺措施用于实际生产,并生产出多品种、大批量的产品。     

商用空调室外机冷凝器的布局和设计分析

冷凝器是空调室外机中的重要零部件,根据其结构形式的不同可分为多种不同的类型。商用空调中常用类型为翅片管式冷凝器,它在不同类型的空调室外机中有不同的布局和结构。本文重点分析商用顶出风空调室外机中冷凝器的布局和设计。     

Asthma‐related outcomes associated with indoor air pollutants among schoolchildren from four informal settlements in two municipalities in the Western Cape Province of South Africa

The health impact of indoor air pollution in informal settlement households has not been extensively studied in South Africa. This cross‐sectional study investigated the association between asthma and common indoor exposures among schoolchildren from four informal settlements located in two municipalities in the Western Cape Province. A total of 590 children, aged 9‐11 years, were recruited. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered to caregivers. Pulmonary function assessment included spirometry and fractional exhaled nitric oxide (FeNO). Phadiatop test for atopy was done. The prevalence of doctor‐diagnosed asthma was 3.4% (n = 20) among whom only 50% were on treatment. The prevalence of current wheeze was 12.9%, and 17.6% had airway obstruction (FEV₁ < lower limit of normal), while 10.2% had airway inflammation (FeNO > 35 ppb). In adjusted logistic regression models, dampness, visible mold growth, paraffin use for cooking, and passive smoking were associated with a twofold to threefold increased risk in upper and lower airway outcomes. The strongest association was that of visible mold growth with rhinitis (adjusted odds ratio—aOR 3.37, 95% CI: 1.69‐6.71). Thus, there is a need for improved diagnosis of childhood asthma and Indoor Air Quality in informal settlement households.     

广州市老年人使用空气调节设备状况及对健康影响调查

老人的健康与建筑室内环境存在重要联系，为了给适老建筑的暖通系统优化设计提供理论依据，有必要探究室内空气调节设备与老人健康的关系。对广州市104位本地老年人进行了问卷调查，收集了老年人的基本健康信息和家庭使用空气调节设备的情况，包括制冷、除湿、采暖和空气净化4种设备及其使用时长，使用习惯。收集到的信息用SPSS20.0进行了统计分析。结果包括广州市老年人家中四种设备拥有率、设备平均使用龄、设备使用时间以及常见日均使用时长；所调查的老年人健康比例达到55.8%。患病老人中心血管疾病的比例最高，其余为风湿性疾病和关节炎等疾病。相关性分析表明，广州地区夏天家庭采取制冷措施的老人患病可能性更小；制冷设备常见日均使用时长与身处空调区域时长的比值越大，老人患病的可能性越小。