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Energy saving has become a key concern of metro systems to reduce operating costs and meet the requirements of sustainable development. Energy-efficient timetabling, an effective way to reduce traction energy consumption, has gotten much attention in recent decades. However, limited research about energy-efficient timetabling simultaneously considered realistic speed profiles and the influence of train loads, which change greatly in different sections and significantly affect energy consumption. Therefore, this paper proposes an energy-efficient timetabling approach to improve regenerative energy utilization based on varying train loads and realistic speed profiles for bidirectional metro lines. First, based on the operational and safety constraints, this paper constructs an integer energy-efficient timetabling model where dwell times and nonuniform headways are taken as decision variables. Besides, the turnaround process is also considered to ensure rolling stock circulation efficiency. Sectional passenger volumes are employed to determine the varying train loads. Energy consumption is calculated based on realistic speed profiles. Owing to the complexity of the model, an improved adaptive large neighborhood search (ALNS) algorithm is designed to solve this model according to its characteristics. Finally, numerical examples are conducted based on the practical data from Shanghai Metro Line 17. The results indicate that the proposed approach effectively solves the energy-efficient timetabling problem with varying train loads and realistic speed profiles for bi-directional metro lines. The approach is suitable for off peak hours and can reduce energy consumption effectively, and the reduction is up to 11.9% for the presented cases. The improved ALNS algorithm can find good solutions within reasonable times in different cases. Moreover, compared with the widely used genetic algorithm in the literature, the improved ALNS algorithm is more efficient in solving the proposed energy-efficient timetabling problem in different cases. [ABSTRACT FROM AUTHOR]

Limited research has been directed toward coastal protection infrastructure compared to other types of infrastructure, despite the increasing global population in low-elevated coastal regions and the threats posed by climate change. This paper presents a risk-based asset management framework for coastal protection structures that improves accuracy with each inspection. The framework consists of five components: the Coastal Asset Inventory (CAI), Inspection and Condition Assessment (ICA) module, Backward Markovian Deterioration Model (BMDM), Forward Markovian Deterioration Model (FMDM), and Intervention Policy Engine (IPE). The framework addresses challenges in accurately predicting coastal structure deterioration due to uncertainties in wave loading conditions and the need for frequent inspections. It is applied to rubble-mound breakwaters in Alexandria, Egypt. The BMDM and FMDM models are developed based on inspection data, and the IPE optimizes interventions considering structural condition, risk thresholds, and budget constraints. Results showed that long-term deterioration estimates occur at an accelerated rate with an increase in inspection points, triggering earlier interventions. However, the framework proves reliable even with only two inspection points, allowing asset managing agencies to implement the model based on the structural condition at the year of construction and a minimum of two inspections. The proposed risk-based asset management framework provided a comprehensive approach to managing coastal protection infrastructure, reducing risks to life and property. By accurately predicting deterioration and optimizing intervention decisions, the framework can greatly assist in the effective management and maintenance of coastal assets. This is vital in ensuring the safety of coastal populations facing global climate change and demographic growth. Coastal protection structures are crucial for safeguarding coastal populations in the face of climate change and demographic growth. This research paper introduces a risk-based asset management framework for coastal protection structures, with practical applications for coastal management agencies and practitioners. The framework addresses the challenges of predicting coastal structure deterioration and optimizing intervention decisions. The framework consists of five components: the Coastal Asset Inventory (CAI), Inspection and Condition Assessment (ICA), Backward Markovian Deterioration Model (BMDM), Forward Markovian Deterioration Model (FMDM), and Intervention Policy Engine (IPE). It has been successfully applied to rubble-mound breakwaters in Alexandria, Egypt. The practical implications are significant: The framework enables asset managers to make informed decisions on coastal infrastructure maintenance and interventions, reducing risks to life and property. It provides a comprehensive approach to managing coastal protection infrastructure and ensuring the safety of coastal populations. By accurately predicting deterioration and optimizing interventions, the framework supports effective management and maintenance of coastal assets. Its reliability and flexibility make it a valuable tool for coastal management practitioners, promoting sustainable development and safeguarding coastal areas. With its potential for broader application, this risk-based asset management framework offers practical solutions for coastal protection worldwide. [ABSTRACT FROM AUTHOR]

Residential skyscrapers (RSs) are very relevant to all aspects of sustainable development as an integral component of urban development. The need for high-rise buildings was first identified in Chicago in the later part of the nineteenth century. Today, more and more skyscrapers are being built to accommodate occupants in the small available land plots in the world's megacities. In this paper, following the review of previous studies, a series of effective indicators are prioritized so that a model for the investigation of the sustainability performance in RSs that is related to the three aspects of sustainability is presented. The RSs should be designed to respond to different requirements during their life cycle, which includes environmental, social, and economic aspects of sustainable development in the initial design that results in a higher quality of life in the RSs. The method used in this paper is a multicriteria decision-making (MCDM) method for sustainability assessment and the integrated value model for sustainable assessment (MIVES). Nine RSs as case studies have been evaluated in Dubai, United Arab Emirates (UAE). Based on the multicriteria model used in this paper, the analyzed RSs in Dubai, UAE, have a sustainability performance in the range of 0.29 < SI < 0.62, where SI is the sustainability index. The objective of this paper is to evaluate the residential skyscraper's (RSs) sustainability based on the integrated value model for sustainable assessment (MIVES), which is a decision-making approach. For the literature review, no high-rise building design and construction studies cover all the pillars of sustainability. Therefore, nine case studies were chosen in Dubai, United Arab Emirates (UAE), and these were evaluated with the MIVES approach. The MIVES integrates three sustainability requirements (environmental, economic, and social), which use the concept of value functions and indicators based on the weight assignment. The formulas for the sustainability index (SI) were defined in this model. Each of these case studies has been quantitatively assessed, and the degree of sustainability of each tower was determined. All these data and results provided a framework and reference to establish a minimum SI that future RSs that are constructed in Dubai, UAE, should achieve. In addition, the evaluation of RSs might be reviewed from other dimensions of sustainability, for example, landscapes for the design of outdoor spaces. [ABSTRACT FROM AUTHOR]

Technology innovation in prefabricated buildings (PBs) is an important way to realize transformation upgrading and green development for the construction industry. The existing literature focuses on the influence of different types of policies on PB development while ignoring the importance of technology innovation. In addition, there are still inconsistent conclusions in the evaluation of the influence of policies on technology innovation. Using the difference-in-differences method and panel data from 2011 to 2020 covering 25 provinces of China, this study investigates the mechanism and impact of five different technological and economic policies on PB technology innovation. The results show that technological support policy, land supply policy, fiscal subsidy policy, and preferential tax policy have a significantly positive impact on PB technology innovation. However, financial policy has no significant effect on PB technology innovation. This paper not only makes theoretical contributions to PB policy research, but also provides the government with a more precise and effective policy toolbox to promote technology innovation in the PB industry or other industries. [ABSTRACT FROM AUTHOR]

A vertical extension (VE) involves the construction of additional floor space on top of an existing base building. With growing urban populations and an urgency to reduce building-related carbon emissions, VEs might have the potential to be a sustainable and innovative solution to overcome the shortage of urban spaces. However, despite the growing number of projects and the emerging academic literature, limited research has documented the decisions that inform the development of VE projects or the lessons learned from stakeholders that were involved in their creation. This paper presents the early decision-making processes that are undertaken to select a VE as an appropriate development type to construct in practice, and the common challenges and solutions during its realization, through semistructured interviews with a broad range of stakeholders, including developers, contractors, architects, and structural engineers that have been involved in recently completed VE projects. The results identify that the main driver of VEs is economic profit, followed by sustainability goals and the desire to stay on the same site. The challenges are related to the complex design and coordination of VE projects, and onsite construction challenges. In addition, this paper identifies the diverse structural support and reinforcement strategies that are used in VEs and contributes to the knowledge by capturing the different aesthetic and construction approaches that are used in practice. [ABSTRACT FROM AUTHOR]

In light of the challenges posed by climate change and rural revitalization, high-quality construction in rural areas is facing significant obstacles from rainstorm flooding. This study adopts a regional disaster system analysis framework and examines the characteristics of rural rainstorm flooding disasters, including the instability of the breeding environment, the hazard characteristics, and the vulnerability of the exposure. Using this framework, we explore the various causes of rainstorm flooding in rural China, assess the effectiveness of responses to these disasters, and examine the differences between urban and rural responses. Our analysis reveals that the increase in rainstorm flooding in rural China is a complex result of multiple factors, including increased risk, instability, and vulnerability. While rural areas have made some progress in monitoring and responding to rainstorm flooding disasters, they remain weaker than cities in terms of governance and disaster management systems. To address these challenges, we recommend increased attention to rural flood control and disaster reduction, stronger preparation for disaster prevention and reduction plans, enhanced rural disaster infrastructure defense, increased financial support for water conservancy projects, and stronger professional emergency response teams, disaster relief equipment, and materials. Additionally, we recommend strengthening disaster prevention and reduction education and publicity among rural residents to promote the ability to self-rescue and mutual rescue. The disastrous impact of climate change and resulting extreme weather events on rural areas has become increasingly evident in recent years. China's vast rural areas have been particularly affected by frequent rainstorm flooding disasters. This paper identifies the increase in rainstorms, the instability of the disaster breeding environment in rural areas, and the increased vulnerability of exposures in these areas as the main reasons behind the intensification of rural rainstorm flooding. To mitigate the impact of these disasters, attention should be paid to natural disaster risk management, normalized flood control, and disaster reduction in rural areas. This requires overall coordination of rural disaster prevention and reduction planning, emphasis on improving the defense capacity of rural areas, increasing financial support for defensive water conservancy projects, promoting the construction of professional emergency rescue teams in rural areas, scientifically distributing flood prevention and disaster relief equipment and materials, strengthening publicity and education on disaster prevention and reduction, and enhancing rural disaster prevention awareness and self-rescue and mutual rescue capabilities. [ABSTRACT FROM AUTHOR]

The article presents a notification for readers to submit their research papers for another special issue on Sustainability Education in Civil and Environmental Engineering of the "Journal of Professional Issues in Engineering Education and Practice."

The article encourages readers to submit papers to the publication regarding engineering management for sustainable development.

In the Chengdu-Chongqing economic circle in China, the recommended bearing capacity of a medium-weathering mudstone foundation is less than the capacity of the rock structure to withstand loads. The aim of this paper was to perform plate loading tests (PLTs) with binocular vision measurement (BVM) to obtain the accurate deformation of the foundation under vertical loading. The results revealed that vertical load–bearing foundations have a failure mode that can be reduced to that of thrust failures for thin bedded structures of mudstone foundations. By analyzing the differences in results between the PLTs and the uniaxial compressive strength tests under the same conditions, a new formalism for calculating foundation-bearing capacity was proposed; there is only a 5% difference compared to in situ tests. The results of this research provide theoretical support and a practical benchmark for the full development of the load-bearing capability of soft red rocks. As the Chengdu-Chongqing economic circle progresses toward the international urban cluster, inevitably, soft rock is used as a foundation retaining layer in the construction of superhigh and super-rise buildings in the region. However, owing to antiquated testing methods and poor intelligibility of the testing equipment, the bearing capacity of such a mass of rock has yet to be fully developed and cannot meet the dual-carbon economic goals and sustainable development of architectural design. Based on this, the study introduces a noncontact method to measure the bearing capacity of soft rock within the traditional method of in situ testing and combines the concept of big data analysis to advance an empirical method for calculating the bearing capacity accurately. Based on the results of this study, the concept of natural foundations can be adopted and the engineering dilemma that the treatment of building foundations cannot be economical and practical can be solved. [ABSTRACT FROM AUTHOR]

Public–private partnership (PPP) has been positioned as a relevant contracting method for developing large-scale infrastructure projects that entails potentially high-magnitude negative impacts on the environment. The effectiveness of the environmental impact assessment (EIA) is crucial to achieving sustainable development of these large-scale infrastructure projects. To unravel the drivers for the EIA effectiveness and the multiple combinations built by the complexity of these drivers, this paper analyzes 28 road PPP projects from Colombia employing a fuzzy-set qualitative comparative analysis (fsQCA) approach. This paper decodes conjectural causal links between specific conditions grouped in superordinate clusters (i.e., consultants' capability, project features, and communities' participation) and EIA effectiveness dimensions (i.e., normative, procedural, substantive, and transactive). Findings revealed that no single combination of causal conditions ensures multidimensional EIA effectiveness. This study demonstrated that EIA effectiveness relies significantly on the integration of specific features of three external stakeholders: consultants, nonpreferred proponents, and communities. This study constitutes the first empirical multidimensional identification of the combination of conditions that generate EIA effectiveness in road PPPs. [ABSTRACT FROM AUTHOR]

An increasing number of disasters across the globe have prompted the creation of strategies for disaster risk reduction and resilience to save lives and property in line with the 2030 Agenda for Sustainable Development and the New Urban Agenda (NUA). The 2030 Agenda calls for all development planning to simultaneously tackle disaster risk reduction and inclusiveness. This paper aims to remold urban planning for upcoming new towns in developing countries so that planners can be able to include indigenous knowledge systems in urban planning. The study was conducted in a new town, Gokwe, Zimbabwe, with a population of 8,118 from which a sample size of 229 was drawn using Cochran's sample size determination formula and the 30% rule. A mixed-methods analytic case study was conducted to evaluate the potential of the town's planning processes in preventing natural and human-induced disasters. The study used questionnaires, semistructured interviews, desktop sources, focus group discussions, and remote sensing. It analyzed the strategies, scope, and relevance of Gokwe town disaster risk-reduction strategies and their integration into town planning and development using six wards, from 1992 to 2020. The Urban Disaster Reduction Index (UDRI) model was applied based on the Sendai Framework for Disaster Risk Reduction indicators to measure the extent to which the town council's development planning can help to reduce disaster and foster sustainable development. The UDRI was calculated for the four Sendai Framework priority areas and proved that the council's disaster management is weak. The chief cause was found to be the town's development control regulations and the national urban councils act that excludes contributions from local communities and leadership, placing new town planning in the hands of bureaucrats, technicians, and politicians only. It was concluded that for disaster management to improve requires local DRR and national urban development policies reformulation. This research exposed that the practice and scholarship of urban planning in most low-income countries such as Zimbabwe must be changed from mere physical design to a holistic process approach of community building. There is need to redefine sustainable development as a dynamic and continuous approach that brings together physical considerations, societal values, and technology in crafting solutions for urban development challenges. Environmentalists, planners, policymakers, engineers, economists, and society at large must combine forces to bring about the most sought-after urban sustainability that ensures environmental protection, spatial coordination, and economic and social development for the present and future generations. The paper calls for adoption of a dynamic multidisciplinary and cyclic rather than the current static and unidirectional planning advanced by traditional urban planning theories, such as the rational–comprehensive, incremental, and the transactive theories. Urban planning should not be viewed as a technical, empirical, and scientific activity that does not require any input from ordinary citizens. Planning processes should afford the public an active role, not only in planning but right from policy setting, planning, development, and management of the established town. Town development should be a mutual process in which leaders gather more information from the community and for the community. [ABSTRACT FROM AUTHOR]

Owing to the influence of urbanization and globalization, many villages in China are transforming from traditional agricultural villages into postproductive villages. Changes in the industrial structures of these villages have caused corresponding environmental problems, which restrict rural sustainable development. Village planning is an important public policy instrument that is used to guide and regulate the construction and governance of villages and, therefore, it is an important tool to realize sustainable development in rural areas. Based on the problems that are experienced by these villages and the goal of rural sustainable development, this paper will use the village planning compilation as the framework, the Delphi method, and the analytic hierarchy process (AHP) to construct an operable and evaluable planning indicator system and uses Xufu village, which is a typical postproductive village in the Yangtze River Delta, China as an example for the analysis. The case study has proven that the indicator system has guiding significance for the compilation of village sustainable development planning, and the relative evaluation method objectively reflected the sustainable development trend of villages before and after the compilation and implementation of planning. This paper will create a tool for the quantitative evaluation of the compilation and implementation of village planning. The results could provide a reference for planning and developing strategies for sustainable village development. [ABSTRACT FROM AUTHOR]

This paper tests China's three-dimensional intergovernmental competition in terms of land leasing. Using the land-leasing data of China's prefecture-level cities from 2003 to 2019 collected from China Land Market, and with the help of the dynamic spatial Durbin model, we show that in the land-leasing behavior of prefecture-level cities in China, three-dimensional government competition does exist and that the influence coefficient from high to low is the government competition of different periods in the same region, shown as horizontal government competition and vertical government competition, respectively. In particular, China's government competition and regional economic development show a clear correlation. We find obvious heterogeneity: in the eastern region, the government competition for land leasing started earlier and has now begun to transform. However, the three-dimensional government competition in the western region lags behind the national level. Therefore, urban development should emerge from the mindset of blindly focusing on the expansion of urban areas, paying more attention to the guiding role of urban planning in urban development and promoting cities on the path of sustainable development by improving the efficiency of land use. [ABSTRACT FROM AUTHOR]

Payments for watershed management link upstream inhabitants whose actions affect water resources with downstream water users. This paper evaluates the effect of plausible shifts in watershed land use on hydrologic services on the Kona coast of Hawai'i Island by measuring vegetation effects on hydrologic fluxes, modeling land-use change impact on the water-supply aquifer, and evaluating the local water department's associated pumping expenses. Transitions between native and plantation forest will have a 25-40% greater impact on the aquifer than the transition from pasture to either forest type. However, for all transitions, the value to the water department is just 2-5% of the opportunity cost to landowners. To provide context for these findings, the effects of these land transitions on carbon storage, provision of native bird habitat, and land stewardship are assessed. Estimates show that delivery of other services does not always increase when water services increase and suggest that the value of impacts to these other services are greater than effects on water. In Kona, as in any watershed payment project, the particular physical and social context determines which services are valuable. [ABSTRACT FROM AUTHOR]

Recycling solid construction waste is an inevitable trend to be followed for the realization of sustainable economic development. The bond behavior of reinforcement and recycled-fiber recycled concrete is discussed in this paper based on the observations of a half-beam unidirectional pullout test. With different recycled aggregates replacement ratios and recycled fibers volume content as variables, the pullout behavior, ultimate bond stress, and bond-slip under monotonic loading are evaluated. The test comprises two parts: direct pullout test and pullout test after the attachment of strain gauges inside the reinforcement. The results show that the half-beam unidirectional pullout test can suitably reflect the bond performance between recycled-fiber recycled concrete and reinforcement. The replacement rate of recycled aggregates exhibits a significant effect on the bond behavior between reinforcement and concrete, and the bond stress reduces by 36.92% when the replacement ratio is 100%. Adding recycled fibers is proposed to improve the bond behavior between recycled concrete and reinforcement; more specifically, the addition of 0.12% recycled fibers can increase the bond stress by 11.34% when the replacement ratio of the recycled aggregates is 50%. Moreover, the bond-slip curve relationship model between recycled-fiber recycled concrete and reinforcement that suitably correlates with the experimental results is established. Finally, the bond stress distribution is nonuniform. With the increase in the pullout force, bond stress causes local stress concentration. The more recycled aggregates, the speedier the bond stress transfer; furthermore, a moderate amount of recycled fiber can alleviate the stress concentration phenomenon. This research proposes a novel method of bond behavior test; furthermore, a novel recycled-fiber recycled concrete material is proposed that could be utilized in actual construction, and the recommended dosages are provided. [ABSTRACT FROM AUTHOR]

Assessing disaster resilience is one of the important research issues for disaster risk management. The process of postdisaster recovery (PDR) involves multiple stakeholders, and their expectations and engagement are considered a key factor for the success of PDR projects. This paper is oriented toward sustainable development, combined with the demands of many stakeholders, and proposes a comprehensive recovery evaluation that considers the sustainability of community resilience. Based on internet public opinion (IPO), a novel method integrating a modified analytic hierarchy process (AHP) and hesitant fuzzy linguistics (HFL) is introduced to guarantee multiple stakeholders' engagement. Specifically, literature research and field interviews are combined with IPO data using text mining techniques to establish evaluation indices. The evaluation results indicate that the overall recovery level of the Lushan earthquake is between fairly and slightly good. It reveals that balances between social (e.g., infrastructure reconstruction, public services and economic recovery, etc.) and individual aspects (e.g., housing allowance, life recovery, mental health, etc.) are needed for recovery improvements. Moreover, housing is regarded as the most urgent and critical task in PDR. Accordingly, increasing requirements for the protection of intangible heritages are anticipated. Finally, possible policies on recovery and poverty alleviation are recommended. [ABSTRACT FROM AUTHOR]

The ability to retrospectively evaluate the vulnerability of a watershed can identify potential risks influencing sustainable water development over time. More importantly, the effect of watershed management policies can be evaluated to help government assess and improve current policies. In order to identify vulnerability factors and evaluate the vulnerability state of a watershed, this paper proposes a time-series-based vulnerability analysis framework that integrates several approaches and methods, including: (1) a combined driving force-pressure-state-impact-response (DPSIR) and hydrology-environment-life (HEL) framework for the selection and classification of evaluation parameters; (2) the coefficient of variation method to determine the weights of the evaluation parameters; and (3) the space geometry model to determine the vulnerability level. In addition, the paper describes a robustness analysis that was performed to evaluate the impact of changing the evaluation parameters on the results. A case study of the Xiang Jiang watershed in China is presented; empirical analysis showed that hydrologic vulnerability experienced large interannual variations. The environmental vulnerability of the Xiang Jiang watershed is subject to a high level of risk, whereas the living vulnerability is subject to a low level of risk. Despite many challenges, Xiang Jiang watershed water development is sustainable; this was determined based on the decreasing trend of total vulnerability. The findings demonstrated the effectiveness of the local government's policies for watershed management. Moreover, the results of the robustness analysis showed that the proposed vulnerability analysis framework was adaptable to using slightly different evaluation parameters in cases in which data for the proposed parameters are not readily available. The proposed framework can be used by local governments and decision makers to effectively manage the sustainable development of watersheds. [ABSTRACT FROM AUTHOR]

Production of alkali-activated binders is a developing research field that utilizes industrial/agricultural by-products and solid waste for the development of sustainable concrete. This paper comprehensively reviews the literature relating to rice husk ash (RHA)–based alkali-activated binders incorporating fly ash (low/high calcium) and blast furnace slag. The literature demonstrates that the properties of raw material significantly influence the formation of the alkali-activated gel matrix. Every precursor (low/high calcium fly ash and slag) that is used to develop alkali-activated binders with RHA have their own reaction mechanism dependant on their specific chemical composition. Hence the incorporation of RHA influences each binder in a unique way depending upon the alkali activation process and reaction mechanisms. The incorporation of RHA, in the range 5%–15%, with blended slag alkali activated binders, yields better compressive strength, when compared with RHA blended with fly ash (low/high calcium). The review presented in this paper is very useful to understand the behavior of alkali-activated binders incorporating RHA and in advancing the research into the successful application of RHA as a binder for alkali-activated materials. [ABSTRACT FROM AUTHOR]

Sustainable rural planning is a continuous, multiparticipatory, large-scale process. Most rural areas in developing countries have sustainable characteristics. However, rural areas have been neglected due to the excessive focus on urban areas, resulting in an urban–rural gap that is difficult to overcome. Village planning is an important public policy instrument that is used to direct land-use planning and management. Therefore, it is an important tool for realizing sustainable development in rural areas. Based on the problems experienced by these villages and the goal of sustainable rural development, the study took An Nijād village, Yemen, as a case study. The study used a hybrid design approach, including qualitative and quantitative methods, such as questionnaire analysis along with GIS methods, and strengths, weaknesses, opportunities, and threats (SWOT). The research cycle was implemented in various phases, including data collection, coding, and analysis. The results of the change matrix (2010–2020) have indicated that land use/land covers (LULC) classified were arable land (47.9%), Built-up area (11.5%), barren/bare land (8.3%), water body (0.3%), slop land (6.4%), mountains (22.1%), and roads (3.5%). This paper will create a comprehensive framework for the implementation and planning of rural areas at the regional level, considering the constraints of each region in terms of its ability to achieve realistic results on the planning and development of sustainable rural development strategies. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study investigating the recyclability of ground granulated blast-furnace slag (GGBFS) base geopolymer concrete as recycled aggregates (RAs) for both geopolymer concrete (GPC) and portland cement concrete (PCC). The effects of partial (0%, 25%, 50%, and 100%) replacement of recycled geopolymer concrete aggregates (RGAs) with natural aggregates (NAs), as fine and coarse aggregate, in either type of recycled geopolymer concrete (RGPC) and recycled portland cement concrete (RPCC) under ambient-cured conditions in similar laboratory circumstances was evaluated. The results were compared with those of recycled concrete counterparts made by recycled cement concrete aggregates (RCAs). A wide range of basic and mechanical properties [i.e., density, compressive strength, ultrasonic pulse velocity (UPV), tensile strength, flexural strength, and modulus of elasticity, water absorption, and shrinkage] along with scanning electron microscopy (SEM) analysis was investigated. The results highlight the high potential of RGAs in both RGPC and RPCC in terms of compressive and tensile strength with only an average reduction of 10% to 15% in 50% substitution of RGAs with NAs. However, there seems to be an incompatibility in using the heterogeneous type of recycled concrete aggregate and binder, which led to more dispersion of test result values. The results in the modulus of elasticity showed a negligible decrease of 3% to 6% by RAs substitution with NAs compared with the control samples. The reductions in flexural strength, water absorption, and shrinkage of RGPC were found to be slight, more than RPCC, which seems to be mainly attributed to the differences in properties and characteristics of geopolymer paste than the influence of RAs content. However, further incorporation of RAs content of more than 50% was found to lead to more significant negative effects in all recycled concrete groups, but the substitution of 50% RGAs to NAs as an optimum mixed proportion due to promising results can be considered for more investigation. GPC is known as a sustainable alternative to PCC, admittedly with more compatibility with the environment. By expanding the use of GPC in the construction industry in the near future, the end-of-life strategies of this material should inevitably be considered as an upcoming concern according to sustainable development policies. Although recycling and reusing of PCC has been widely investigated in many studies for years, the applicability of using GPC itself as a recyclable material to be used for recycled concrete has been barely studied. Therefore, this study compares the properties of slag-based geopolymer recycled concrete with conventional cement-based recycled concrete. The results indicate the promising potential of GPC recyclability for partial replacement of recycled aggregate with natural aggregate and acceptable mechanical properties and durability as a sustainable material for the construction industry. The geopolymer recycled concretes recorded better compressive and tensile strengths and similar modulus of elasticity compared with cement-based recycled concrete. Additionally, the results in flexural strength, water absorption, and shrinkage of cement-based recycled concrete indicated a better behavior over time, which is more attributed to the characteristics of geopolymer binder rather than recycled aggregates. However, incorporation of RAs content of more than 50% was found to lead to more adverse effects in all recycled concrete groups. [ABSTRACT FROM AUTHOR]

In recent decades, rapid urbanization has presented many social, economic, cultural, environmental, and physical challenges and threats in big cities. Sustainable small city development (SSCD) is a sustainable utilised way for reducing the rural–urban population from rural settlements to big cities. In this regard, this research looks to analyze the role of five dimensions—economic, cultural, social, environmental, and physical indicators—in the Golbaf city development in Kerman County, Kerman province, Iran. For this purpose, this paper presents a scientific sustainable model in small cities development using the size of the sample (374 residents). These 374 cases have been selected by the Cochran formula. The SPSS software package 23 has been used to analyze data (T regression test). This research uses the analytic hierarchy process model to prioritize factors affecting the development of Golbaf city. In addition, this research has used the Friedman test to evaluate the similarity of important factors. The results of the research indicate that the environmental indicator is in the first rank and the two indicators of culture and economy are in the next rank of factors affecting the development of Golbaf city. [ABSTRACT FROM AUTHOR]

In order to solve the problem of semirigid base damage in the initial period of use, this paper focused on emulsified-asphalt cold recycled mixtures with all old mineral and analyzed its strength formation mechanism. The optimum moisture content and amount of emulsified asphalt in the regenerated base were determined through tests, whereas the performance of the mixtures was verified according to the designed optimum ratio. The gray correlation method was used to analyze the performance-influencing factors and determine the rationality of the base designs. The research results can be used for pavement base recycling with a new solution for old roads, and the efficiency of pavement construction was greatly improved. It also reduced the heat and energy loss and contributed to the sustainable environmentally development of road construction. [ABSTRACT FROM AUTHOR]

This paper reports the results of research on the application of nanomaterials to improve the quality and durability of road infrastructure. The research investigated road transportation infrastructure failures and the feasibility of preventive engineering solutions using nanotechnology. Laboratory experiments were conducted on different treated and untreated Nigerian soil samples (laterite, clay, and black soils) to study the changes in their fundamental geotechnical properties. Common engineering standards were used for the experiments and results analysis. Laboratory tests showed that treated laterite and clay soils had improved the liquid limit, plastic limit, and shrinkage index, including hydrophobic properties. The California bearing ratio (CBR) improved by as much as 87-125%. However, the black soil sample only passed the hydrophobicity test. The black soil did not exhibit any bearing strength in the CBR test, even after treatment with the nanomaterial. The paper contributes to understanding how nanomaterials can be used to engineer construction materials (laterite and clay soils), used in road pavements, and alter their normal geotechnical properties. This construction innovation results in improved performance characteristics. The paper also makes a pedagogical contribution by discussing the basic science and reaction chemistry that underpin material transformation processes and performance enhancement. This contributes to construction engineering practice and durable, economic, and sustainable highway infrastructure. The paper discusses the empirical results and gives recommendations on further work. [ABSTRACT FROM AUTHOR]

Most African countries in the world currently face significant conflict on how colonial spatial planning legislation governs contemporary spatial planning practices. Spatial development is controlled by various pieces of spatial planning legislation, which include statutes and bylaws. The spatial planning legislation that was in place before Zimbabwe and Zambia attained independence influenced development and this continues to date. This paper focuses on how colonial spatial planning legislation influenced and still influences spatial development in Zimbabwe and Zambia. The methodology of this paper includes a review and analysis of published documents on spatial planning. The spatial planning legislation for both countries will be reviewed. This paper noted that British colonial spatial planning legislation was biased toward Europeans and disadvantaged Africans. This paper reveals that colonial spatial planning legislation influenced spatial development in both colonial and postcolonial Zimbabwe and Zambia. The implanted aspects of the legislation were difficult to recover from, especially in Zimbabwe. However, Zambia reviewed its spatial planning legislation in 2015 and adopted sustainable integrated development plans. [ABSTRACT FROM AUTHOR]

Recently, computer–physical systems provide a critical service together with physical and computer elements including integrated and robust medical services, a smart electricity grid, the green cloud, and air traffic control. While sustainable energy is becoming increasingly important as globally concern issues are being recognized, and energy supply and uses are becoming critical. To provide this ubiquity, energy efficient and cheap functionality to cyber physical systems, the information available from the physical environment is required under the related law. This paper describes a sustainability cyber construction resource modeling algorithm, which, via a broad range of real-world data, almost builds a smart city model with a distribution network (DN). It consists of different energy management systems models that control consumer power systems and simulate energy, loss, and tension flux in the DN. In addition, scenarios such as photovoltaic deployment and the penetration of electric vehicles estimate indices that calculate the sustainable urban model, for instance carbon emission to address social security issues. It is possible to view the tests and the interface as extremely versatile and ideal for different types of intelligent city problems. [ABSTRACT FROM AUTHOR]

Transit-oriented development (TOD) is characterized as compact, mixed-use, and pedestrian-friendly development around transit stations, aiming to balance land use and transportation, enhance sustainability, and improve public transport accessibility. There are various TOD assessment methods; each target one of these goals. This paper proposes a comprehensive approach that addresses TOD goals in a multistage assessment. In the first stage, we identify station areas' typology using weighted node, place, and tie indices based on the correlation between land use and transportation. Then, feasible station areas for enhancing density and diversity are selected using a canonical score. In the second stage, station areas' typology is defined by sustainability criteria and a TOD index. Then, the efficiency of selected station areas for compactness is assessed using Data Envelopment Analysis. Finally, public transport accessibility is optimized for these stations in the third stage. We investigate the effects of weighting indicators of the node–place model in the first stage and aggregation methods in the second stage. We conduct a feasibility and efficiency assessment for the typology of station areas in Metro Montreal. This study attempts to advocate a holistic perspective for TOD assessment with a case study implementation. [ABSTRACT FROM AUTHOR]

The paper focuses on the analysis of biologically active areas of the city in terms applicable to the understanding of green infrastructure in their spatial and urban planning references. The paper is an expanded account of the writers' research on green infrastructure resources of the city of Lodz, concerning the spatial identification of green infrastructure and its diversity in spatial arrangement, extracting elements of its structure, as well as their functional diversity in relation to urban zones of the city. The research described in this paper also associated with an attempt to characterize elements of green infrastructure in chosen urban zones. The motivation to undertake the research reported in this paper was to look for ways to improve the analyzing and description of the green infrastructure of a city for the purpose of development planning. As a result of this paper, contributions to the analysis of urban green infrastructure were indicated. Reliable identification of morphological structure (diversity construction) of the current state of green infrastructure is crucial in the process of its modeling and determines the future direction of its development in the urban-industrial agglomerations. [ABSTRACT FROM AUTHOR]

Achieving sustainability through the market has been a research topic in the field of sustainable development. Nevertheless, the ways in which sustainability in construction is influenced by the construction market have not been explored explicitly. In the research reported in this paper, hypotheses on the effects of market competition on the sustainability performance of the construction industry were proposed. A structural equation modeling approach was adopted and data from 30 provincial construction sectors in China were collected to test the proposed hypotheses. The results show that market competition can influence industrial sustainability in three ways, namely (1) positive effects on the economic dimension, (2) negative effects on the environmental dimension, and (3) positive effects on the social dimension. The research reported in this paper contributes to the body of knowledge by addressing the role of market competition in institutional drivers of sustainable construction. It is implied that the construction industry has the importance of placing business competition on the tenets of sustainable development. Governmental authorities are thus recommended to include the triple bottom line of sustainability as a benchmark for measuring the efficiency of industrial competition policies. Clients are also suggested to stipulate sustainable construction as a contractor selection criterion in bid documents to improve sustainability in construction. [ABSTRACT FROM AUTHOR]

As public utility owners face increased budget constraints and greater expectations, alternative project delivery methods will increasingly be used to fast track projects, reduce costs, promote innovation, and ensure proper performance for water and wastewater facilities. The goals of public utility owners and U.S. federal tax regulations suggest why design-build-operate (DBO) projects have been selected over other procurement processes. The research reported in this paper contributes to the body of knowledge and benefits industry practitioners, by identifying tax regulations and best practices that when jointly considered improve the project delivery selection process, while enhancing risk-mitigation efforts on DBO water and wastewater projects. A procurement selection process using multiple-criteria decision and financial risk analyses is presented to select the most economically sustainable delivery method given each project's characteristics. A present value analysis establishes a range of values that takes into account variables that will potentially impact lifecycle costs. The selection of the procurement process and the contractor is based on best value where financial risks to the concerned government and contractor are mitigated through dynamic service fee agreements in accordance with current U.S. federal tax regulations. [ABSTRACT FROM AUTHOR]

The article presents the discussion and closure for the article "Simulating Activated Sludge System by Simple-to-Advanced Models," by H. Shahriari, C. Eskicioglu, and R. L. Droste published in January 2006 in the "Journal of Environmental Engineering." According to Derin Ohron, Ozlem Karahan and G. Insel, the conceptual understanding of complex biochemical reactions is related to substrate use by microbial systems. The authors of the article suggests that the study uses an infant formula, a complex substrate purposely chosen to simulate processes occuring in an activated sludge process treating sewage.

Green building (GB) is gaining increased acceptance in the construction industry as a viable solution for meeting the growing demand for environmentally friendly or healthy buildings. However, the uptake of GB technologies is not as apparent as it should have been. This paper aims to examine the criticality of various barriers preventing the wider adoption of GB technologies. Results from statistical analyses of 104 questionnaire survey responses from GB experts around the world are presented. The results validated the criticality of 19 of the 26 barriers used for the survey. Respondents from different countries and with diverse backgrounds displayed broad consensus on the criticality levels of the barriers. Resistance of stakeholders to change and higher cost are identified as the most critical barriers to implementing GB technologies. Generally, the various groups of respondents shared similar views on the number of barriers affecting the industry; however, respondents with more than 15 years of experience in GB perceived fewer barriers. The factor analysis showed that the barriers to GB technologies adoption could be grouped into five main interrelated components, which suggest the need for holistic and integrated strategies to overcome the barriers. The findings of this paper could help policy makers identify specific problems in GB technologies adoption and develop suitable strategies for their wider uptake. From the perspective of international experts, this study contributes to the body of knowledge about GB barriers. [ABSTRACT FROM AUTHOR]

With the adoption of the United Nations' Agenda 2030, some member states of the European Union have voluntarily assessed their state regarding the 17 Sustainable Development Goals (SDGs) by use of the United Nations' monitoring system for administrative bodies. However, this system does not consider specific challenges in achieving SDGs that are faced with respect to vulnerable geographical contexts. Among these contexts falls the emblematic case of insular regions suffering from particular natural and geographical "handicaps" that, in most cases, confine their efforts to SDG achievements. The goal of this paper is to feature a monitoring system that is capable of measuring progress of insular territorial contexts to 2030 SDGs; the study is adjusted to the islands' particularities. In doing so, the link between the structural problems of the islands and the UN 2030 SDGs is established, feeding the design of a monitoring mechanism by means of an Islands Sustainable Development Index (IISD). IISD integrates environmental, social, economic, and innovation dimensions, represented by four core indicators, namely the IEND, ISD, IED, and IID, respectively. The results of this research demonstrate: (i) the need to assess progress of the islands toward the SDGs, taking into account the "insularity" dimension, that is, incorporating in the monitoring system respective intrinsic and extrinsic peculiarities of such territorial contexts; and (ii) how intrinsic quantitative and qualitative attributes of island regions, embedded in an integrated analytical approach, can inform strategic decision making in order to achieve higher levels of sustainability performance in these specific territorial entities. [ABSTRACT FROM AUTHOR]

Changes in surface or groundwater management influence water use patterns as well as the economic value and sustainability of all water uses. In water-scarce regions, programs that establish environmental flows usually involve reallocating water from another productive use. Few peer-reviewed papers to date have investigated impacts on system-wide economic performance resulting from environmental flow regimes. This work presents an original approach to address that gap by developing and applying a basin-scale hydroeconomic optimization model of North America's Middle Rio Grande Basin to explore impacts of environmental pulse flows on the region's economy and water stocks. The model accounts for surface and groundwater storage, irrigation, urban, recreational, and environmental demands; surface water inflows under various climate scenarios; groundwater pumping and recharge; substitute water prices; crop water use; evaporation; as well as institutional constraints governing water use. Results show that climate change, in the form of highly variable inflows, has an impact on the total and marginal cost of implementing environmental pulse flows, amplified by the conjunctive nature of the system. [ABSTRACT FROM AUTHOR]

Sediment accumulation in reservoirs across the world diminishes reservoir benefits, increases maintenance costs, and damages the environment. United States regulatory policy requires State and Federal permits for discharging sediment into waterways, which has tended to discourage alternatives that pass sediment downstream of the dam. The cost of methods that remove the sediment from the fluvial system is usually prohibitive and is a major factor precluding sustainable sediment management in the United States and other countries with similar sediment reduction policies. This paper challenges the notion that US policy requires sediment removal and terrestrial storage by highlighting seven case studies in the United States where reservoir sediment management included downstream sediment discharge. Where technically feasible, these types of solutions can lead to greater economic and environmental sustainability of US reservoirs. [ABSTRACT FROM AUTHOR]

Modern society is demanding that the use of energy associated with construction and operation of structures be investigated during the planning and design phases. The engineering community has been striving to design more sustainable buildings in an attempt to reduce both raw material requirements and energy use during all phases of design. Structural engineers currently have very limited guidance on how to incorporate sustainability concepts in their designs. Innovative methods are needed to address the environmental impact, energy use, and other sustainability issues faced during planning and design of buildings. This paper investigates and discusses five sustainable structural design methodologies: Minimizing Material Use, Minimizing Material Production Energy, Minimizing Embodied Energy, Life-Cycle Analysis/Inventory/Assessment, and Maximizing Structural System Reuse. The goal of this paper is to describe and address issues associated with the proposed design methodologies to determine which, if any, can produce the most sustainable structural designs. It was determined that no single methodology can address all the issues surrounding sustainable structural design. Also, it was determined that combinations of two or more methodologies may increase the ability of design professionals to produce more sustainable designs. [ABSTRACT FROM AUTHOR]

This paper discusses a framework for incorporating sustainable design/thinking as a new civil engineering course and experiences from the pilot offering. Important areas are outlined to aid all engineers in understanding sustainability in context with traditional engineering principles. Green-building rating systems were used to introduce the concepts of sustainability in buildings and infrastructure, highlighted by presentations from green-building professionals. By providing a better understanding of sustainability through education, civil engineers can provide proactive solutions to a growing global infrastructure. [ABSTRACT FROM AUTHOR]

Considerable research has been carried out on the optimization of water distribution systems (WDSs) over the last three decades. In previous research, attention has mainly focused on the minimization of cost, due to the high expenditure associated with the construction and maintenance of such systems. However, the impacts of WDSs on the environment usually have not been considered adequately. The recent increasing awareness of sustainability and climate change, especially global warming, has led to research where greenhouse gas (GHG) emissions are considered. In the study described in this paper a multiobjective genetic algorithm for WDS optimization has been used as an explorative tool to investigate the trade-offs between the traditional economic objective of minimizing costs and an additional environmental objective of minimizing GHG emissions. The impacts of minimizing GHG emissions on the results of WDS optimization have been explored for a case study in this paper. The results indicate that the inclusion of GHG emission minimization as one of the objectives results in significant trade-offs between the economic and environmental objectives. Furthermore, a sensitivity analysis has been conducted by using different discount rates in a present value analysis for computing both ongoing costs and GHG emissions. The results obtained show that the Pareto-optimal front is very sensitive to the discount rates used. As a result, the selection of discount rates has a significant impact on final decision making. [ABSTRACT FROM AUTHOR]

It is widely recognized that sustainability should be incorporated into engineering education. To prepare students with sustainability knowledge and techniques, engineering educators need to develop appropriate class contents and effective teaching techniques. Based on experience from developing and teaching a sustainability course within the construction management program in the civil engineering department, this paper discusses the process of identifying sustainability knowledge areas, course planning, and lessons learned from the class. The paper also includes main class topics as well as students’ feedbacks, both of which may serve as a starting point for continuous improvement of sustainability education in construction. [ABSTRACT FROM AUTHOR]

This paper presents a multicriteria decision-making approach to evaluate contractor candidates in the open competition of construction project procurement by means of a knowledge-framed analytic network process (KANP), which embeds a construction knowledge framework into a formal analytic network process procedure. An applied KANP model named KANP.BID is set up and used in an experimental case study. The paper concludes that the KANP.BID model is a viable and capable tool for selecting the most appropriate tender alternative under criteria of sustainable construction. It is expected that the proposed KANP.BID model can attract interest from both practitioners and researchers in terms of further research and development. [ABSTRACT FROM AUTHOR]

The concern over sustainable development gives rise to the importance of the environmental factors in evaluating an environment-sensitive project. In this regard, the widely adopted exercise which involves the environmental impact assessment (EIA) and the traditional cost–benefit analysis (CBA) in a sequential way may be flawed with a failure to calculate the resultant economic and environmental impacts in the same setting and at the same time. It is mainly because the EIA is qualitative in nature and hence the environmental impacts are hard and difficult to translate into monetary terms. In contrast, by monetizing the environmental impacts, the study shows that it is feasible to integrate the CBA with the environmental factors on an equal basis. The empirical base of the paper draws on the case of the Pinglin Interchange in Taiwan. In particular, the empirical results show that an integrated CBA may produce an entirely different conclusion from the one resulting from the common traditional EIA and CBA exercises. This is because the EIA focuses mainly on the quantity of pollution, but the latter depends on the socioeconomic context. [ABSTRACT FROM AUTHOR]

The relocation of logistics facilities toward the periphery of urban areas—that is, logistics sprawl—is a major challenge for policymakers due to the impacts on the economic geography of suburban areas and associated changes in truck traffic pattern. The logistics sprawl considerably affects the vehicle kilometers traveled (VKT) since logistics facilities are the origin or destination nodes for urban freight transport. The effect of logistics sprawl, coupled with industry category, employment size, fleet ownership, and cohort on the VKT, is an unaddressed research area that requires significant research attention. To quantify the effects of logistics sprawl on the VKT, this paper utilizes establishment-based freight survey (EBFS) data to perform a cross-sectional analysis of urban and suburban logistics facilities. The distinct variations in the effects of logistics sprawl across multiple industry types are investigated using the EBFS data. The combined model indicated that the VKT generally increases as an establishment is located away from a city center. Compared with the establishments' VKT in Sprawl 1, the VKT for establishments in Sprawl 2, 3, and 4 increases by 6.39, 4.12, and 6.06 km, respectively. Classified industry model results demonstrated that the sprawl effect on the VKT is industry specific. Establishments dealing with food products demonstrated a positive relation between the average VKT and the distance of an establishment from a city center. However, the sprawl effect was not consistent for establishments dealing with wood products, plastic and rubber products, mineral products, and metal and metal-related products. Moreover, the developed cohort model indicated an average VKT increase by 29.42 and 46.43 km for establishments that started operations in the postindustrialization and postliberalization periods, respectively, compared with the establishments being operational from the postindependence period. This investigation's tangible outcome is to present the influencing factors of the VKT, which will be beneficial for policymakers to develop industry-specific guidelines on land use, employment restructuring, and subsidies on owning different types of commercial vehicles. [ABSTRACT FROM AUTHOR]

Geotechnical engineers can and should take a leading role in incorporating sustainable development goals into the selection of ground improvement design alternatives and construction methods through quantitative assessment of environmental impacts. Since all valid design alternatives must meet project performance requirements, overall cost and environmental impact become two key factors in the decision process. Although methods of cost estimation are well established within geotechnical engineering, simplified methods for assessing impacts to the environment have remained a largely unfulfilled need. In this paper, life cycle analysis, embodied energy, and carbon footprinting are reviewed in the context of geotechnical ground improvement. It is proposed that estimates of life cycle embodied energy and carbon dioxide emissions may be used during the design process by geotechnical engineers to quantify some of the effects of ground improvement on the environment. The life cycle is considered to extend from raw material extraction to the completion of construction. The background presented herein forms the basis for a streamlined energy and emissions assessment model (SEEAM), described in a companion paper. [ABSTRACT FROM AUTHOR]

This paper documents successful use of portland-limestone cement (PLC) with 50% replacement of cement using supplementary cementitious materials (SCMs) during expansion and renovation of a college football stadium. Concrete becomes more sustainable as clinker content is reduced, and use of PLC in place of ordinary portland cement (OPC), e.g., such as per a common U.S. national standard, has considerable appeal, especially if performance tradeoffs that are often associated with more sustainable concrete can be addressed. Higher replacement of cement in concrete with SCMs may also be possible by incorporating PLC, further adding value to projects from performance and sustainability perspectives. Concrete containing PLC was successfully used in approximately 1,900 m3 of on-grade and structural concrete flatwork. The cementitious system contained 50% PLC, 30% slag cement, and 20% Class C fly ash. This paper provides information related to properties of the PLC supplied to the stadium project as they are not necessarily typical of PLCs used worldwide over the past several years. One especially beneficial performance trend was that early-age strength gain of concrete containing 50% PLC, 30% slag cement, and 20% Class C fly ash was noticeably better than that of otherwise comparable concrete containing OPC. Additionally, use of PLC did not result in finishing problems, reduced slump by approximately 20 mm, reduced set time by approximately 1 h, and improved chloride ion resistance. [ABSTRACT FROM AUTHOR]

In sustainable international development projects, a negotiation guideline for donor and recipient countries is essential to reduce conflicts among various stakeholders in project-based organizations (PBOs) consisting of leadership, senior executioner board, change management board, and executioner. This paper presents a guide focusing on the roles and responsibilities (R&R) of stakeholders according to the hierarchy in PBOs. R&R are classified to keep sustainability at multiple levels while balancing three controversial values: economic growth, social equity, and environmental protection. The proposed guideline was constructed from a literature review as a theoretical framework of R&R and relevant sustainability factors. Moreover, the guide was validated by conducting semistructured interviews and surveys with high-level decision makers. The results show that focused values and potential risks can be identified according to individual R&R in PBOs. Furthermore, sharing responsibilities among levels is necessary. This includes balancing sustainability values between the environmental and non-environmental aspects at the upper level and deploying full-time on-site managers to avoid conflicts with locals at the execution level. [ABSTRACT FROM AUTHOR]

Connectivity is an important aspect of the landscape pattern on influencing function and services. This paper analyzes the dynamics of urban green connectivity of Shenzhen, China, from years 1986-2010 and examines the temperature regulation function, based on remote sensing and a field survey. The connectivity degree of urban green was classified as core, islet, edge, perforation, bridge, loop, and branch by using the linear spectral mixing method and morphological spatial pattern analysis (MSPA). The results demonstrated that patterns and functions of connectivity categories have changed greatly during urbanization. The increasing areas of edge, branch, and bridge resulted in cooling the environments. It showed that perforation is the best category to keep thermal environments stable by being surrounded with large green areas. By comparing the results of statistics and buffer analysis, islet, edge, bridge, and branch contributed to decreasing temperature of nongreen areas in surrounding areas. The findings can improve the understanding of relationship between urban green connectivity and its climate regulation function, and supply the evidence for urban planning and green-corridor planning. [ABSTRACT FROM AUTHOR]

In China, rapid city expansion and the consequent loss and fragmentation of green spaces presents a major challenge for urban planners wanting to maintain urban sustainability. The aim of this paper is to formulate a workable framework to plan and manage urban green infrastructure for urban sustainability through a case study of Longgang, a typical developed area in China. Urban green infrastructure is associated with various landscape types, which have different functional niches in a UGI network. By integrating morphological spatial pattern analysis (MSPA) into landscape ecological principles based on a geographic information system, the functional niches of landscapes were defined as core areas, connectors, islets, and three levels of potential connectors. Then a future urban green infrastructure scenario with hierarchical hubs, links, and sites was delineated. Finally, by contrasting the plan scenario and the basic ecological control line (BECL) of Longgang, some focus areas for management strategies were proposed. With this approach, green infrastructure elements are preserved first in a given region, and new greening element locations and adaptive measures are emphasized. It is hoped that this framework could be used to promote the spatial navigation of urban green-space system planning and urban sustainability in China. [ABSTRACT FROM AUTHOR]

The research reported in this paper determined the effect of combined microwave irradiation and NaOH pretreatment on solubilization and biodegradation in anaerobic digestion of waste-activated sludge (WAS). Solubilization increased significantly with NaOH concentration (20-60 meqNaOH=L) and microwave final temperature (100-170°C). However, the experimental trials did not adequately approximate the response surface for volatile solids reduction, cumulative biogas production, and biogas yield. Within the design boundaries, the maximum solubilization degree (72%) of WAS occurred at 60 meq=L and 170°C. The highest volatile solids removal efficiency (62.4%) was achieved at 40 meq=L and 170°C. Cumulative biogas production and yield were 2.3-5.7 L=L and 154-393 mL=g added volatile solids, respectively, and both parameters were highest at 20 meq=L and 135°C. [ABSTRACT FROM AUTHOR]

Recent decades have seen extensive use of public-private partnerships (PPP) in international infrastructure development from governments, private construction firms, and humanitarian organizations. Given the high social importance of civil infrastructure, considerable research attention has sought factors that lead to successful PPP. In a contribution to this body of work, and to the theory of the social sustainability of infrastructure, this paper presents statistical evidence showing that the choice of how to engage private investment in infrastructure is not culturally neutral. This analysis is built on a World Bank database of 1,792 railroad, seaport, airport, and toll road projects with private investment from 27 low- and middle-income nations and Hofstede's cultural dimensions. Multinomial logistic regression shows that there are statistically significant relationships between Hofstede's cultural dimensions and the various methods used to enable private investment in infrastructure projects. For all transport project types aggregated together, high power distance index scores predict the use of private funds in projects involving the construction of new infrastructure, while high individualism-collectivism and uncertainty avoidance scores predict the use of private funds in brownfield projects. Toll roads, which change a cultural norm regarding how most roads are accessed and paid for, emerged as a divergent technology type. Railroads are the technology type most strongly influenced by cultural dimensions. Engineers and policymakers may use these results to understand what forms of private investment in transportation infrastructure are more likely to be culturally acceptable in a wide variety of local contexts. [ABSTRACT FROM AUTHOR]

Green building rating systems are developed to promote sustainability. Existing rating systems use both numerical and linguistic descriptors. In addition, existing rating systems do not directly identify the priority or interrelation between different parameters. The objectives of this study are to develop a priority weights-based green building rating model with numerical descriptors and to propose a remediation plan for existing buildings to obtain green certification under the developed rating model. In this paper, the analytical hierarchy process is used to develop a green building rating system. Based on the opinions of 100 experts, the priority weights of parameters were determined. The numerical thresholds of point allocation, equations, and priority weights of the proposed rating model supports a definitive classification on green building performance. For buildings with poor green performance, a remediation plan is proposed that can be adopted to upgrade and obtain green certification for buildings under the developed rating model. [ABSTRACT FROM AUTHOR]

This paper reviews policy and research initiatives that have begun to address three major challenges to incorporate regional environmental impacts in the design and optimization of drinking water distribution systems. These challenges are to (1) develop a regulatory framework to limit the environmental impacts linked to upgrades and operation of water networks; (2) select indicators and develop models to quantify energy use, environmental impacts, and emissions for the design and operation of water distribution systems; and (3) develop decision support systems to integrate environmental sustainability objectives into the decision-making process for utilities. This paper concludes by discussing realistic steps that water utilities can take to reduce the environmental impact of their business operations. [ABSTRACT FROM AUTHOR]