Optimization of cool roof and night ventilation in office buildings: A case study in Xiamen, China

Increasing roof albedo (using a “cool” roof) and night ventilation are passive cooling technologies that can reduce the cooling loads in buildings, but existing studies have not comprehensively explored the potential benefits of integrating these two technologies. This study combines an experiment in the summer and transition seasons with an annual simulation so as to evaluate the thermal performance, energy savings and thermal comfort improvement that could be obtained by coupling a cool roof with night ventilation. A holistic approach integrating sensitivity analysis and multi-objective optimization is developed to explore key design parameters (roof albedo, night ventilation air change rate, roof insulation level and internal thermal mass level) and optimal design options for the combined application of the cool roof and night ventilation. The proposed approach is validated and demonstrated through studies on a six-storey office building in Xiamen, a cooling-dominated city in southeast China. Simulations show that combining a cool roof with night ventilation can significantly decrease the annual cooling energy consumption by 27% compared to using a black roof without night ventilation and by 13% compared to using a cool roof without night ventilation. Roof albedo is the most influential parameter for both building energy performance and indoor thermal comfort. Optimal use of the cool roof and night ventilation can reduce the annual cooling energy use by 28% during occupied hours when air-conditioners are on and reduce the uncomfortable time slightly during occupied hours when air-conditioners are off

Contribution of infrastructure to the township's sustainable development in Southwest China

Townships in Southwest China are usually located in mountainous regions, which are abundant in natural and cultural landscape resources. There are additional requirements for the township’s sustainable development in these areas. However, insufficient infrastructures, due to limited resources, constrain the sustainable development of these townships. Sustainable contribution of infrastructure (SCOI) in this study is defined as the performance of infrastructure as a contribution to the coordinated development among economic, social, and environmental dimensions of township’s sustainable development. It is necessary to assess these infrastructures according to SCOI and provide choices for investment to maximize resource utilization. Therefore, an assessing model of SCOI with 26 general indicators was developed, which covers five most urgently needed infrastructures of these townships in Southwest China, including road transport, sewage treatment, waste disposal, water supply, and gas. In this model, quantitative and qualitative methods are combined to acquire different SCOI of each infrastructure. The result of the SCOI would be an important reference for infrastructure investment. A case study of Jiansheng Town, that is located in the Dadukou district of Chongqing, demonstrates the applicability of the model. It shows the assessing model of SCOI is efficient to identify the most valuable infrastructure that is appropriate for investment with the goal of township’s sustainable development. This study can provide insights for infrastructure investment and management in townships or areas

Efficiency of environmental legislative measures to ICT industry in China with case of Chongqing City - from geographical view

Le résumé en français n'a pas été communiqué par l'auteur.Le résumé en anglais n'a pas été communiqué par l'auteur

Efficiency of environmental legislative measures to ICT industry in China with case of Chongqing City - from geographical view

Le résumé en français n'a pas été communiqué par l'auteur.Le résumé en anglais n'a pas été communiqué par l'auteur

End-of-life vehicle (ELV) recycling management: improving performance using an ISM approach

With booming of the automobile industry, China has become the country with increasing car ownership all over the world. However, the end-of-life vehicle (ELV) recycling industry is at infancy, and there is little systematic review on ELV recycling management, as well as low adoption amongst domestic automobile industry. This study presents a literature review and an interpretive structural modeling (ISM) approach is employed to identify the drivers towards Chinese ELV recycling business from government, recycling organizations and consumer’s perspectives, so as to improve the sustainability of automobile supply chain by providing some strategic insights. The results derived from the ISM analysis manifest that regulations on auto-factory, disassembly technique, and value mining of recycling business are the essential ingredients. It is most effective and efficient to promote ELV recycling business by improving these attributes, also the driving and dependence power analysis are deemed to provide guidance on performance improvement of ELV recycling in the Chinese market

Competition rule of the multi-criteria approach: What contractors in China really want?

© 2018 The Author(s). Recent years have witnessed the diversifying means of competitive bidding, where the client plays a critical role in the determination of competition rule. It is widely recognized that the competition rule should be placed on a win-win basis to ensure that both the client and contractors are well considered with respect to their interests. Nevertheless, a vast majority of biddings fail to take account of what contractors really want. Using the methods of literature review and content analysis, 34 tender evaluation factors are proposed to compose the competition rule in China. Contractors’ opinions on these factors are collected by virtue of questionnaire survey. Based on the Pareto law, it is found that the competition rule encompasses eleven key factors, and the composition varies slightly between public and private sectors. The Hotelling’s T test is conducted on those key factors in common. The implication is that contractors can use indifferent factors (e.g., credit rating, construction plan, completeness of bid components, timely payment to workers) to improve competitiveness, while the client may utilize different factors to diversify the competition rule. This paper probably presents an earliest effort put to examine the acceptability of competition rule in the construction context

Management of rural residential housing construction in China's new village development: an empirical study

With the continuous advancement of the construction of beautiful new countryside (CBNC) in China, rural housing construction (RHC) h as ushered in an unprecedented opportunity. The investment, progress, governance, and security of rural housing construction in new villages have troubled local governments and farmers. These problems have always affected farmers satisfaction with housing . The literature and practice mostly focus on project coordination, project group management, housing security, rural assistance, rural culture, housing standards, housing policies, dilapidated house renovation. The study focused on the main line of RHC, i dentified stakeholders of RHC management, studied relevant factors affecting farmers’ satisfaction with the quality of RHC, analyzed the satisfaction degree of RHC management, and determined the degree of influence, based on which problems of land use, con struction control, and process supervision are solved, and suggestions about investment, quality and safety, and progress control were provided. Through data review, questionnaire survey, quantitative analysis and induction, RHC situation in Suining, Sichu an Province was selected as an example, and the satisfaction model was constructed through stakeholder related research. The overall housing satisfaction was relatively high, and two thirds of rural residents were satisfied with their existing housing. Thr ough SWOT strategic analysis, it was innovatively proposed to implement agency construction model (ACM) in RHC in the context of CBNC, which provides a more scientific management path for RHC in the context of CBNC.Com o avanço contínuo da construção de novas e belas paisagens (CBNC) na China, especialmente em 2017, quando o Comitê Central do Partido Comunista da China (CPC) propôs a est ratégia de revitalização rural, a CNBC foi aprimorada e o desenvolvimento de áreas rurais encontra outra perspetiva, portanto, a construção de moradias rurais (RHC) inaugurou uma oportunidade sem precedentes, e a área rural viu uma melhoria substantiva das moradias rurais. Nesse contexto, a gestão do RHC tornou se uma grande preocupação, o que preocupa governos e agricultores locais, especialmente se os agricultores estão satisfeitos, quão satisfeitos estão, quais problemas pendentes existem, como melhorar essas questões, entre outros, tornaram se o foco principal de gestão do RHC no CBNC. Esta pesquisa toma o RHC e sua gestão como a linha principal, seleciona o RHC em Suining, província de Sichuan como exemplo, usa os princípios básicos da gestão do RHC e c ombina a pesquisa e a prática de especialistas e estudiosos em gestão de CBNC e RHC na China recentemente. anos. Como resultado, no contexto do CBNC, o autor conduziu um estudo empírico através da construção de um modelo de avaliação de satisfação, usou a SWOT para propor sugestões estratégicas para o RHC no contexto do CBNC e propôs o modelo de construção da agência (ACM) para RHC. O estudo enfoca a principal linha de RHC no contexto do CBNC e expõe os princípios de gerenciamento do RHC no contexto do CBNC , das partes interessadas e outras teorias. O autor conduziu um estudo empírico sobre a satisfação da qualidade do RCH com o gerenciamento do RHC em Suining como exemplo, e analisou as deficiências do gerenciamento do RHC antes de apresentar sugestões, o q ue abre um novo modelo para o gerenciamento do RHC no contexto de CBNC para governos locais e agricultores

Therblig-embedded value stream mapping method for lean energy machining

To improve energy efficiency, extensive studies have focused on the cutting parameters optimization in the machining process. Actually, non-cutting activities (NCA) occur frequently during machining and this is a promising way to save energy through optimizing NCA without changing the cutting parameters. However, it is difficult for the existing methods to accurately determine and reduce the energy wastes (EW) in NCA. To fill this gap, a novel Therblig-embedded Value Stream Mapping (TVSM) method is proposed to improve the energy transparency and clearly show and reduce the EW in NCA. The Future-State-Map (FSM) of TVSM can be built by minimizing non-cutting activities and Therbligs. By implementing the FSM, time and energy efficiencies can be improved without decreasing the machining quality, which is consistent with the goal of lean energy machining. The method is validated by a machining case study, the results show that the total energy is reduced by 7.65%, and the time efficiency of the value-added activities is improved by 8.12% , and the energy efficiency of value-added activities and Therbligs are raised by 4.95% and 1.58%, respectively. This approach can be applied to reduce the EW of NCA, to support designers to design high energy efficiency machining processes during process planning

Prevailing construction and demolition waste management practices : a China study

The construction industry is regarded as one of the largest generators of solid waste in the world. These large amounts of construction and demolition waste generated by continuous construction activities have harmful effects on the environment. China is the largest producer of construction and demolition waste, with an annual generation of 2.4 billion tonnes. Moreover, with the continued development of their construction industry, the total volume of construction and demolition waste generated in China is forecasted to reach 3.96 billion tonnes by 2020. However, without proper management, a significant amount of construction and demolition waste has inevitably occupied land resources. In the current age of enhanced environmental awareness, transformation to sustainable management in the construction sector is needed. Despite the increasing awareness of recycling in industry, the average recovery rate of construction and demolition waste in China is only approximately 5%. Few developed countries have a sustainable society with an orderly, reasonable, and effective construction and demolition waste management system. However, as most of the waste in China is directly dumped or landfilled, it lags far behind these high-performance countries. The objectives of this study were to obtain information about the current status of construction and demolition waste management in China from comparative analyses and case studies, and to identify the obstacles to the promotion of recycling. Recovery rates of construction and demolition waste were collected from 35 countries, and the existing policies, standards, and official documents at a national level in China and seven selected countries with high performance (including Japan, South Korea, Germany, Austria, the Netherlands, Italy, and the United Kingdom) were reviewed. The comparative analysis revealed the reasons for China’s unsatisfactory performance. These reasons included the following: (1) inadequate guidance on recycling, (2) an underdeveloped recycling market, (3) incomplete knowledge of stakeholders’ responsibilities, (4) ineffective cooperation among governing bodies, (5) a lack of penalty for other stakeholders, and (6) an ineffective supervision system. Few studies have been performed to evaluate construction and demolition waste management performance of different Chinese cities, although case studies have been performed on specific cities. In the present study, site visits to 10 different Chinese cities were conducted: Shanghai (Direct-administered municipalities), Hangzhou (Zhejiang Province), Suzhou (Jiangsu Province), Chongqing (Direct-administered municipalities), Chengdu (Sichuan Province), Xi’an (Shaanxi Province), Changsha (Hunan Province), Shenzhen (Guangdong Province), Nanjing (Jiangsu Province), and Zhoukou (Henan Province). Construction and demolition waste management performance, as well as the obstacles for waste management, varies among these Chinese cities. These obstacles included the following: (1) a lack of sources of construction and demolition waste, (2) a lack of guidance on the application of building materials recycled from waste, (3) a lack of land use for fixed industries, (4) a lack of precise estimations of the waste amount and distribution, (5) a lack of guidance on the classification of construction and demolition waste, (6) unrestrictive landfilling, (7) inconsistent cooperation among different official governments, (8) inadequate research on the use of recycled products and waste separation, and (9) an incomplete waste traceability system. If these obstacles are more fully understood, recommendations can be provided to enhance construction and demolition waste management in China. Policymakers in China can consider the following suggestions: (1) ensuring the stability of construction and demolition waste sources; (2) precise estimation of waste generation and distribution; (3) an effective waste tracing system; (4) improvements in related technology; (5) expanding financial incentives; (6) prioritising the recycling of waste and promoting waste reduction; (7) completion of waste classification and relevant standards; (8) strict landfill bans; (9) consistent cooperation among governmental departments; and (10) expansion of the recycling market