Sustainable procurement is an emerging theme in the construction industry across the globe. However, organizations in the construction industry often encounter impediments in improving environmental performance in construction projects, especially in procurement. Besides its other facets, procurement of construction equipment is inherited to be capital-intensive and vital for managing environmental concerns associated with built environment projects. In this regard, selection criteria in such procurement processes are generally supportive of considering cost and engineering specifications as key parameters. However, sustainability apprehensions in today’s Malaysian construction industry have mounted pressure on industry professionals to rethink their equipment acquisition strategies. The notion of green or sustainable procurement is still infancy for the Malaysian construction industry and facing challenges for embedding it in the current procurement practices. This research aims to address these apprehensions by considering six main criteria, namely, life cycle cost (LCC), performance (P), system capability (SC), operational convenience (OC), environmental impact (EI), and social benefits (SBs), and their 38 subcriteria towards procurement of sustainable construction equipment. A multicriteria-based equipment selection framework on the triple bottom line of sustainability in the context of the Malaysian construction industry has been developed and tested. The application of analytical hierarchy process (AHP) established the sustainable procurement index with a consistent sensitivity analysis results. As such, the proposed procurement index shall help decision-makers in the process of the acquisition of sustainable construction equipment in Malaysia.

Electricity demand in Pakistan has consistently increased in the past two decades. However, this demand is so far partially met due to insufficient supply, inefficient power plants, high transmission and distribution system losses, lack of effective planning efforts and due coordination. The existing electricity generation also largely depends on the imported fossil fuels, which is a huge burden on the national economy alongside causing colossal loss to the environment. It is also evident from existing government plans that electricity generation from low-cost coal fuels in the near future will further increase the emissions. As such, in this study, following the government’s electricity demand forecast, four supply side scenarios for the study period (2013–2035) have been developed using Long-range Energy Alternatives Planning System (LEAP) software tool. These scenarios are Reference scenario (REF) based on the government’s power expansion plans, and three alternative scenarios, which include, More Renewable (MRR), More Hydro (MRH), and More Hydro Nuclear (MRHN). Furthermore, the associated gaseous emissions (CO2, SO2, NOX, CH4, N2O) are projected under each of these scenarios. The results of this study reveal that the alternative scenarios are more environmentally friendly than the REF scenario where penetration of planned coal-based power generation plants would be the major sources of emissions. It is, therefore, recommended that the government, apart from implementing the existing plans, should consider harnessing the renewable energy sources as indispensable energy sources in the future energy mix for electricity generation to reduce the fossil-fuel import bill and to contain the emissions.

In Pakistan, the utilization of renewable energy sources is increasing in order to reduce the electricity supply and demand gap. However, concentrated solar power (CSP) generation has not been considered in the country even though it has gained considerable attention worldwide. This study, as such, investigates the potential, performance, and economic analyses of four CSP technologies for different locations in Pakistan. Initially, an assessment of CSP sites, including solar resource, land, and water availability, was undertaken. Then, performance simulations of CSP technologies for four different locations of Pakistan, namely Quetta, Hyderabad, Multan, and Peshawar, were examined. For all cases, highest energy production was achieved in summers and lowest in winters, and CSP plants with evaporative cooling were found to be efficient compared to air cooling. The results also revealed that the Quetta and Hyderabad regions were promising for CSP development while parabolic tough (PT) and solar power tower (SPT) were the suitable CSP technologies for these regions. Specifically, the SPT plant with air cooling could be a favorable option for energy production in Quetta. Lastly, economic analyses revealed the financial feasibility of CSP plants in Pakistan since the levelized cost of energy is found to be significantly low.Processes 2019, 7, 575 2 of 26 negligible. Specifically, an abundant potential of solar energy is available in the country because of its location in the sunbelt. Solar energy can be utilized in two ways: solar photovoltaics (SPV) and concentrated solar power (CSP) [4]. SPV systems are used to convert sunlight directly into electricity whereas CSP systems (also known as solar thermal systems) are used for concentrating and heating a heat transfer fluid (HTF) for a power cycle. In Pakistan, the installation and development of the SPV system is growing [4]. Quaid-e-Azam solar park (QASP), which is the first ever power station in the country consisting of SPV with a capacity of 1000 MW, is under construction [4]. Out of 1000 MW of QASP, 300 MW has been already added to the national grid. Also, several small to large scale projects consisting of solar photovoltaics are under operation and construction [4]. However, CSP systems have not been utilized in Pakistan.CSP is a promising technology for large scale power production. There are four families of CSP technology including (i) parabolic trough collectors (PTC), (ii) solar power tower (SPT), (iii) linear Fresnel reflects (LFR), and (iv) parabolic dish systems (PDs). There are numerous advantages of CSP, such as renewable, clean, low operating cost, etc. However, one of the issues with CSP is soiling of mirrors, where dirt is accumulated on the mirrors/reflectors. It causes a reduction in the electricity production. The soiling effect can be reduced by proper cleaning/washing of the mirrors [5][6][7]. The commercialization of CSP is increasing. For instance, the CSP global capacity was 400 MW in 2006, which increased to 4800 MW in 2017 [8]. The global l...

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The current investigation presents a numerical simulation of boundary layer flow with heat transfer. The study primarily emphasizes heat generation due to the influence of nonlinear thermal radiation. Moreover, the simultaneous effects of Joule heating and viscous dissipation have been incorporated for the thermal enhancement of the magnetohydrodynamics (MHD) on the convective boundary layer flow over a flat plate. Dimensional analysis is brought into use to determine the hydro and thermal boundary layer thickness for the two-dimensional flow.Subsequently, the application of the suitable similarity transformation yields a nonlinear coupled flow problem with is solved numerically with the help of the Runge-Kutta Fehlberg (RKF) method incorporated with the Shooting technique. Moreover, this theoretical study highlights the immense mechanical and aeronautical applications of thermal radiation. In view of computational findings and simulating results, linear and nonlinear thermal radiation effects can also be investigated on fluids passing through a cylinder and channels. Finally, computational data tabulated against some pertinent parameters and parametric study reveal that non-linear thermal radiation is more effective for highly viscous fluids.