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Multi-criteria decision approaches are preferred for achieving multi-dimensional sustainable renewable energy goals. A more critical issue faced by the wind power industry is the selection of a location to tap prospective energy, which needs to be evaluated on multiple measures. In this paper, the aim is to assess and rank alternative wind power plant locations in Saudi Arabia. The approach presented here takes multiple criteria into consideration, such as wind speed, wind availability, site advantages, terrain details, risk and uncertainty, technology used, third party support, projected demand, types of customers, and government policies. A comparative analysis of feasible alternatives that satisfy all multi- criteria objectives is carried out. The results obtained are subjected to sensitivity analysis. Concepts such as ‘threshold values’ and ‘attribute weights’ make the approach more sensitive.

This study aims to explore the effects of various pre- and post-weld heat treatments (PWHTs) on the microstructural and mechanical properties of dissimilar aluminium alloys, namely AA7075 and AA2024, joined through rotary friction welding. The joints were rigorously evaluated through multiple characterization methods, revealing no signs of cracking or incomplete bonding. This study observed that dissimilar joints between AA7075 and AA2024 alloys showed increased flash formation on the AA7075 side due to its lower melting point relative to the AA2024 alloy. Various zones within the weld region were identified, such as the dynamic recrystallized zone (DRZ), the thermo-mechanically affected zone (TMAZ)—which includes TMAZ-1 with elongated grains and TMAZ-2 with compressed or distorted grains—the heat-affected zone (HAZ), and the base metal (BM) zone. Of all the welding conditions examined, the post-weld heat-treated (PWHT) AA2024/AA7075 joint produced by rotary friction welding showed the highest strength, with a yield strength (YS) of 305 ± 2 MPa and an ultimate tensile strength (UTS) of 477 ± 3 MPa. This improvement in strength can be attributed to the significant strengthening precipitates of MgZn2 (found on the AA7075 side), θ-Al2Cu, and S-Al2CuMg (found on the AA2204 side) formed during post-weld ageing. Notably, all dissimilar welds failed in the HAZ region on the AA2024 side due to coarse grain formation, identifying this as the weakest area. [ABSTRACT FROM AUTHOR]

Industrial pressure relief valves must function reliably and effectively to protect pressurized systems from excessive pressure conditions. These valves are essential safety devices that act as cushions to protect piping systems, equipment, and vessels from the risks of high pressure, which can cause damage or even explosions. The objectives of this study were to minimize valve failures, decrease the number of rejected valves in the production line, and enhance the overall quality of pressure relief valves. This work introduces an integrated quality improvement methodology known as the hybrid multi-criteria decision-making (MCDM)—failure mode and effects analysis (FMEA) approach. This approach is based on prioritizing crucial factors for any failure modes in the industrial setting. The presented case study demonstrates the application of a hybrid approach for identifying the fundamental causes of industrial pressure relief valve failure modes and malfunctions. This investigation highlights the applicability of FMEA as a methodology for determining causes and executing remedial actions to keep failures from happening again. FMEA helps uncover the underlying causes of industrial pressure relief valve failures, while the integration of the hybrid MCDM methodology enables the application of four integrated MCDM methods to identify crucial factors. The adopted model addresses the shortcomings of the conventional FMEA by accurately analyzing the relationships between the risk factors and by utilizing several MCDM methods to rank failure modes. Following the application of the adopted methodology, it was discovered that the high-risk failure modes for the pressure relief valve included misalignment of wire, normal wear/aging, rejection of machined parts, mismatch of mating parts, and corrosion. Therefore, risk managers should prioritize developing improvement strategies for these five failure modes. Similarly, failures comprising debris, delayed valve opening, internal leakage, premature valve opening, and burr foreign particles were determined as second essential groups for improvement. [ABSTRACT FROM AUTHOR]

This paper deals with the influence of micro-pulsed direct current on microstructure and mechanical properties of gas tungsten arc welding (GTAW) weldments of Ti-6Al-4V (Ti-64). Bead-on-plate GTA welds were made on the samples in the un-pulsed and micro-pulsed (125 Hz and 250 Hz) conditions. Post-weld heat treatment (PWHT) was performed on a few coupons at 700 °C for 3 h in an inert atmosphere, followed by furnace cooling. In the microstructure, the fusion zone (FZ), base metal (BM), and heat-affected zone (HAZ) can be easily distinguished. The top surface of the FZ has large columnar grains because of lower heat loss to the surrounding atmosphere, and the bottom region of the FZ has comparatively smaller equiaxed grains. The micro-pulsed samples' FZ grain size was lower than that of those made without pulsing. This shows that high-frequency current has substantially refined prior β grains. The microstructure of the FZ is characterized by an acicular morphology composed of α, martensitic α′, and retained β phases. The FZ's hardness was higher than the BM due to the presence of martensitic α′. Additionally, the hardness in the HAZ was elevated due to the formation of finer martensitic α′. Micro-pulsed DC welding led to improved mechanical properties, including higher hardness, ultimate tensile strength (UTS), and ductility compared to un-pulsed welding. This enhancement is attributed to the grain refinement achieved with micro-pulsed DC. After PWHT, the prior β grain size remained relatively unchanged compared to the as-welded condition. However, the hardness in the FZ decreased due to the decomposition of α′ into α and β phases. The ductility of all samples improved as a result of the widening of the diffusional α phase. [ABSTRACT FROM AUTHOR]

Acacia gum (AG), a polysaccharide biopolymer, has been adopted to improve the strength of three cohesive soils by subjecting them to diverse environmental aging conditions. Being a polysaccharide and a potentially sustainable construction material, the AG yielded flexible film-like threads after 48 h upon hydration, and its pH value of 4.9 varied marginally with the aging of the stabilized soils. The soil samples for the geotechnical evaluation were subjected to wet mixing and were tested under their Optimum Moisture Content (OMC), as determined by the light compaction method. The addition of AG modified the consistency indices of the soils due to the presence of hydroxyl groups in AG, which also led to a rise in OMC and reduction in Maximum Dry Unit weight (MDU). The Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) were determined under thermal curing at 333 K as well as on the same day of sample preparation. The least performing condition of the soil's CBR was evaluated under submerged conditions after allowing the AG-stabilized specimens to air-cure for a period of 1 week. The UCS specimens tested after 7 days were subjected to the initial 7 days of thermal curing at 333 K. A dosage of 1.5% of AG yielded the UCS of 2530 kN/m2 and CBR of 98.3%, respectively, for the low compressible clay (LCC) after subjecting the sample to 333 K temperature for 1 week. The viscosity of the AG was found to be 214.7 cP at 2% dosage. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and average particle size determination revealed the filling of pores by AG gel solution, adsorption, and hydrogen bonding, which led to improvements in macroproperties. [ABSTRACT FROM AUTHOR]

The relationships between humans and the environment have recently been incorporated into ergonomics in an effort to broaden the discipline's traditional scope. Green ergonomics is an emerging field of study that has discovered links between people's well-being and a sense of connection to nature. The study aims to build a conceptual model to identify the readiness factors for green ergonomics in healthcare organizations, which are the primary focus point of the current study. To determine the readiness factors, a review of the literature and a survey of healthcare experts' opinions were conducted. The healthcare professionals validated the identified readiness factors. Data for this study were gathered using a closed-ended questionnaire and scheduled interviews. The study employed total interpretive structural modeling (TISM) methodology and cross-impact matrix multiplication applied to classification (MICMAC) analysis to address why and how the factors interact and prioritize the identified readiness factors. Ten green ergonomics readiness factors were identified in this study. Design principles (F4), green buildings (F1), ergoecology (F2), audit working practices/risk assessments (F3), and professional practice (F6) had strong driving power and weak dependence, thus being identified as key factors or driving factors for green ergonomics in healthcare organizations. Although the study primarily focused on the readiness factors for green ergonomics in healthcare organizations, the scope could eventually be expanded to explore more areas. Academics and other stakeholders will have a better understanding of the key drivers and the readiness factors for healthcare green ergonomics. In this study, the total interpretive structural modeling (TISM) and cross-impact matrix multiplication applied to classification (MICMAC) analysis for healthcare together are proposed as an innovative approach to address the green ergonomics concept. [ABSTRACT FROM AUTHOR]

The enhancement of mechanical properties in welds is heavily reliant on grain refinement. This study aims to investigate the impact of the addition of AZ61 filler and the impact of the absence of filler on the macrostructure and microstructure, as well as the mechanical properties, of Mg-Al-Zn alloy (AZ31) gas tungsten arc (GTA) welds. The AZ61 filler was employed to introduce a higher concentration of aluminum into the molten pool of AZ31 using the alternating-current GTA welding technique. It has been shown that the welds prepared with AZ61 filler had high strength and low ductility [yield strength (YS): 121 MPa, ultimate tensile strength (UTS): 226 MPa, and percent elongation (%El): 5] when compared with other welds made without filler (YS: 105 MPa, UTS: 164 MPa, and %El: 8), and the presence of the refined equiaxed grains and a significant volume fraction of second-phase Mg17Al12- β particles in the fusion zone (FZ) may explain this phenomenon. The results revealed that the average grain size of the weld decreased from 104 to 56 μm as the Al content in the weld metal increased from 2.7 wt% (without filler) to 4.5 wt% (with AZ61 filler). This grain refinement that was observed with the AZ61 filler may be attributed to the high growth restriction factor value caused by increased constitutional supercooling ahead of the solid-liquid interface. [ABSTRACT FROM AUTHOR]

Due to the convenience of online grocery apps and home delivery, online grocery shopping has become popular in recent years. Globally, consumer behavior has significantly changed the consumption and purchase patterns of online grocery shopping. This study aimed to develop an efficient model for online grocery order fulfillment that both reduces costs and increases supply chain efficiency and sustainability. This study first aimed to develop the current picking model by adopting real-world data from a store in Riyadh, Saudi Arabia. Subsequently, four proposed models were developed to improve the efficiency and sustainability of the online grocery order fulfillment process. The results show a significant improvement in all models over the current picking model. The percentage improvements in fulfillment time per product are as follows: single order picking—8.33%; batch order picking—6.78%; zone order picking—3.08%; and hybrid order picking—13.20%, which combines zone and batch order picking. Retailers and online grocery apps could adopt these models to increase efficiency and sustainability. Also, these models have great potential for future research and improvement by optimizing product placement, in addition to picking methods and picking routes, which are the focus of this study. [ABSTRACT FROM AUTHOR]

The increasing demand for energy and the severe environmental and economic repercussions have contributed to the development of renewables options. The scarcity of fossil fuels and their negative effect on the environment have sparked an alarming situation for alternative energy sources that are cleaner and more sustainable. Waste cooking oil is a valuable feedstock for biodiesel production, but it is often disposed of improperly, causing environmental pollution and health hazards. The current waste cooking oil supply chain in Pakistan and other countries is fragmented, inefficient, and often unregulated, leading to a lack of standardization and quality control. The study aims to develop a comprehensive supply chain model that integrates waste cooking oil collection, transportation, processing, and biodiesel production to create a sustainable value chain that benefits the environment, the economy, and society as a whole. The proposed optimization approach reduces the total expenses associated with the activities of the biodiesel supply chain. Modified possibilistic chance constrained programming (MPCCP) is used as a solution technique to represent this uncertainty. The MPCCP model is solved with the assistance of Lingo 18.0, while fuzzy logic demand forecasting was done using MATLAB. Accordingly, the fuzzy logic designer (FLD) simulation was conducted to demonstrate the applicability and effectiveness of FLD simulation for the particular kind of issue being considered. The research, not only focuses on mitigating environmental and health risks associated with improper waste cooking oil disposal, resulting in reduced pollution and a cleaner environment but it also advocates for the efficient utilization of waste cooking oil as a valuable feedstock for biodiesel production, thereby promoting a more sustainable and renewable energy source. By optimizing supply chain activities and minimizing costs, the research contributes to enhancing economic growth and efficiency within the biodiesel industry. This research encourages further exploration and collaboration among researchers and stakeholders to expand the applications of the proposed model in waste management, renewable energy, and supply chain optimization. [ABSTRACT FROM AUTHOR]

The current work aims to examine the influence of various welding speeds (500, 700, and 800 mm/min) on the microstructure and mechanical characteristics of electron beam–welded Ti-6Al-4V alloy joints. The base metal microstructure was composed of a slightly elongated α phase and a transformed β phase, whereas the fusion zone (FZ) exhibited an acicular martensitic α′ microstructure. This is due to faster cooling rates in the FZ associated with electron beam welding. The welds prepared with a 800 mm/min welding speed showed higher strength and lower ductility [yield strength (YS): 959 ± 6 MPa, ultimate tensile strength (UTS): 993 ± 5 MPa, percent elongation (%El): 8] compared to those prepared with 500 mm/min (YS: 909 ± 4 MPa, UTS: 956 ± 5 MPa, %El: 11). This was due to a decrease in the width of the α-platelets in the FZ owing to faster cooling rates at higher welding speeds. For all welding speeds, samples that underwent post-weld heat treatment (PWHT) displayed a noteworthy reduction in both UTS and hardness values compared to all the as-welded samples. However, the welds at lower welding speeds showed lower strength and higher ductility (YS: 868 ± 5 MPa, UTS: 922 ± 4 MPa, %El: 13) compared to higher welding speeds (YS: 892 ± 5 MPa, UTS: 938 ± 6 MPa, %El: 9) after PWHT. This is due to the formation of the diffusional product α + β phase in the FZ, as evidenced by the transmission electron microscope results. [ABSTRACT FROM AUTHOR]

Worldwide manufacturing and service sectors are choosing to transform the existing manufacturing sector, particularly reconfigurable manufacturing systems using the technologies of the next generation Industry 4.0. In order to satisfy the demands of the fourth industrial revolution, model evaluation and assessing various candidate configurations in reconfigurable manufacturing systems was developed. The proposed model considers evolving consumer demands and evaluates manufacturing configurations using a gray relational approach. For the case at hand, it is evident that considering all possible dynamic market scenarios 1 to 6, the current manufacturing configuration, i.e., alternative 1, has 89% utilization, total 475 h of earliness and 185 h of lateness in the order demand delivery to the market, and a total of 248 throughput hours and around 1143 bottleneck hours. The main challenge is to make a perfect match between the market demands, variations in product geometry, manufacturing processes and several reconfiguration strategies/alternatives. Furthermore, it is evident that alternative 1 should be reconfigured and that alternative 3 is the best choice. Alternative 3 exhibits 86% system utilization, a total of 926 h of earliness and 521 h of lateness in the order demand delivery to the market, and a total of 127 throughput hours and around 853 bottleneck hours. A simulation framework is used to demonstrate the efficacy of each possible reconfigurable production setup. The sensitivity analysis is also carried out by adjusting the weights through principal component analysis and validating the acquired ranking order. Thus, if the decision makers want to provide a preference to all criteria, the order of the choices of configurations is found to be alternative 3, alternative 1, alternative 4, alternative 2 and alternative 5. [ABSTRACT FROM AUTHOR]