Passive Design of Buildings for Extreme Weather Environment

Buildings account for nearly 40% of the end-use energy consumption and carbon emissions globally. Buildings, once built, are used at least for several decades. The building sector therefore holds a significant responsibility for implementing strategies to increase energy efficiency and reduce carbon emissions and thus contribute to global efforts directed toward mitigating the adverse effects of climate change. The work presented in this paper is a part of continuing efforts to identify, analyze and promote the design of low energy, sustainable buildings with special reference to the Kazakhstan locality. Demonstration of improved environmental conditions and impact on energy savings will be outlined through a case study incorporating a passive design approach and detailed computational fluid dynamics analysis for an existing building complex. The influence of orientation and configuration is discussed with reference to energy efficiency and associated wind comfort and safety. The effect of these aspects on energy consumption and comfortable wind environment has been assessed using CFD analysis and proved to be affective. Single building and multiple building configurations have been analyzed and compared. According to the findings, multiple building configurations have better wind conditions when compared with a single standing building. With respect to orientation the former one should be modeled with the fully surrounded side of a “box” opposite to the predominant wind direction whereas the latter one should be located with the rear side opposite to the wind direction. Thus, results indicated that there is a considerable influence of passive design and orientation on energy efficiency, wind comfort and safety. Careful consideration and application of the findings can potentially lead to considerable decrease of energy consumption and, therefore, allow saving money and the environment at the same time

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran