Search Results (38)

In order to balance carbon emissions and cost reduction in China’s steel firms, this study proposes a multi-objective optimization model for carbon emission reduction based on life-cycle assessment. The baseline scenario technique was used to forecast carbon emissions at every stage of the life cycle by 2025, and the costs of reduction for four major initiatives—clean electricity procurement, recycling of scrap steel, fossil fuel consumption reduction, and clean transportation share increase—were systematically accounted. Kernel PCA and NSGA-II algorithms were used to create a multi-objective optimization model with the goal of maximizing emission reductions and reducing reduction costs. The greatest potential and economic gain, according to the results, come from using more scrap steel and using fewer fossil fuels. At 823 million CNY, the cost–benefit balanced solution reduces CO₂ by 3.0358 Mt. This approach achieved virtually maximum emissions reductions at only 10.9% of the cost of the maximum reduction scenario. This study makes two key contributions. First, it provides a systematic life-cycle cost accounting framework for major CO₂ reduction measures in the steel industry. Second, it develops a Kernel PCA-NSGA-II multi-objective optimization model that explicitly resolves the trade-off between abatement cost and emission reduction volume, offering decision support for steel enterprises under different policy and economic scenarios. Full article

The government has established food reserves to support national food security; however, their volume varies widely across regions, and many districts still lack such reserves. The objectives of this study were to analyze the determination of volume and the problems in determining it, management performance, and propose strategies to strengthen food reserves in local governments. This study was conducted in West Java Province in 2022, using primary and secondary data from the study area. Primary data were collected through FGDs with farmer groups and stakeholders from central and regional agencies, and secondary data consisted of food reserve statistics and secondary literature. Quantitative analysis using mathematical equations in accordance with food reserve calculation regulations was used to calculate the potential food reserve production and ideal reserve volume, while qualitative descriptive analysis obtained from the field was used to clarify the results of the analysis. The main findings of this study are as follows. (1) The determination of local government food reserves is regulated by regional policy, with the volume increasing from 23% in 2018 to 187% in 2022 of the ideal volume in West Java; (2) the potential for rice-based food reserves can be expanded in line with regional production capacity, although there are still obstacles, including limited budgets and a lack of commitment from local governments in determining optimal reserve volumes; (3) strengthening regional food reserves must be complemented by the development of community-based reserves; and (4) improving management performance requires supporting regional government policies to ensure sustainable food reserves, adequate warehousing infrastructure, efficient distribution facilities, and effective distribution mechanisms through collaboration with logistics institutions. This study suggests policy recommendations to implement a multi-year cooperation contract with the Logistics Affairs Agency covering procurement, storage, and distribution to expand reserve volumes and improve management effectiveness. Full article

Background: Laparoscopic living donor nephrectomy is a standard approach for kidney procurement, yet optimal technique and learning curve trajectories remain incompletely characterized. We present a high-volume single-center experience with standardized transperitoneal laparoscopic donor nephrectomy and CUSUM-based learning curve analysis. Methods: Retrospective analysis of 1446 consecutive laparoscopic living donor nephrectomies performed by six surgeons between January 2015 and December 2024. Learning curve analysis used the cumulative sum (CUSUM) methodology to identify proficiency phases. The most recent 200 consecutive cases, representing mature institutional performance, were analyzed for detailed outcomes. The surgical technique employed a transperitoneal approach with the GelPOINT^® Advanced Access Platform for kidney extraction via an offset Pfannenstiel incision. Results: CUSUM analysis identified case 669 as the inflection point, defining four phases: Phase I (initial learning, cases 1–250, n = 250, 154.6 ± 35.9 min), Phase II (rapid improvement, cases 251–669, n = 419, 136.7 ± 32.6 min), Phase III (consolidation, cases 670–1000, n = 331, 118.0 ± 30.1 min), and Phase IV (mastery, cases 1001–1446, n = 446, 101.5 ± 26.2 min). Overall operative time decreased from 154.6 to 96.8 min (37.4% reduction, p < 0.001). In the 200-case mastery-phase cohort, mean operative time was 96.8 ± 25.5 min with warm ischemia time of 3.8 ± 1.2 min. There were no conversions to open surgery (0%), no intraoperative complications, and one major postoperative complication (0.5%, Clavien–Dindo ≥ IIIa). Left kidney procurement was performed in 99.5% of cases. Among male donors (n = 86), systematic orchalgia surveillance demonstrated 46.5% prevalence at 1 month, declining to 36.0% at 1 year, and 7.0% at a 5-year follow-up. Conclusions: This high-volume single-center experience demonstrates favorable outcomes in laparoscopic living donor nephrectomy with CUSUM-defined proficiency phases extending beyond 1000 cases. The outcomes observed likely reflect the combined effects of institutional volume, team experience, and standardized technique. Multi-center validation is required before generalizing these results. Full article

Liner shipping companies commonly pursue strategies such as forming strategic alliances and attracting new customers to strengthen competitiveness and improve operational performance. However, in the shipping of perishable goods, inadequate ship scheduling and bunker management can result in substantial customer loss and increased operational costs. This paper examines a scenario in which a large volume of perishable goods is shipped by liner ships. The specific demand characteristics of perishable goods—requiring rapid port handling and expedited shipping—are analyzed. To address these challenges, we propose a mixed-integer nonlinear programming (MINLP) model to optimize ship scheduling and refueling decisions for liner cold chain services under cooperative agreements. The model minimizes total liner shipping service costs while explicitly accounting for the decay of perishable goods. Nonlinear elements are linearized using a piecewise linear secant approximation, enabling efficient solution of the model with commercial solvers. Numerical experiments based on the AEU6 route operated by China COSCO Shipping Group validate the model and provide practical managerial insights. The results indicate that: (1) incorporating collaborative agreements can reduce total route service costs by 4.5% and total port handling costs by 7.5%, while also lowering late arrival penalties and losses from perishable goods decay; (2) joint consideration of refueling strategies and collaborative agreements improves both decision flexibility and solution accuracy; (3) the shipping of perishable goods has differentiated effects across voyage legs, highlighting the need for liner shipping companies to enhance cooperation with ports and refine bunker fuel procurement planning; and (4) it is essential to improve ship performance and appropriately design bunker fuel tank capacity to respond to dynamic changes in the shipping market. Full article

On large-scale product assembly lines, such as those used in aircraft manufacturing, multiple assembly positions and devices often coexist within a single workstation, leading to complex task interactions. As a result, the problem of parallel task execution within workstations must be effectively addressed. This study focuses on positional and equipment conflicts within workstations. To manage positional and equipment conflicts, a multi-objective optimization model is developed that integrates assembly sequence planning with the first type of assembly line balancing problem. This model aims to minimize the number of workstations, balance task loads, and reduce equipment procurement costs. An improved NSGA-II algorithm is proposed by incorporating artificial immune algorithm concepts and neighborhood search. A selection strategy based on dominance rate and concentration is introduced, and crossover and mutation operators are refined to enhance search efficiency under restrictive parallel constraints. Case studies reveal that a chromosome concentration weight of about 0.6 yields superior search performance. Compared with the traditional NSGA-II algorithm, the improved version achieves the same optimal number of workstations but provides a 5% better workload balance, 2% lower cost, a 76% larger hyper-volume, and a 133% increase in Pareto front solutions. The results demonstrate that the proposed algorithm effectively handles assembly line balancing with complex parallel constraints, improving Pareto front quality and maintaining diversity. It offers an efficient, practical optimization strategy for scheduling and resource allocation in large-scale assembly systems. Full article

Early and timely screening for congenital heart disease (CHD) is one of the key challenges for healthcare professionals (HPs). This study aimed to identify barriers to the screening of CHD among healthcare professionals in Khyber Pakhtunkhwa, Pakistan. A qualitative cross-sectional study was conducted among HPs working in public and private hospitals, and data were analyzed thematically using NVivo 10.0 software until saturation following Braun and Clarke’s framework. Data were reported according to the Standards for Reporting Qualitative Research (SRQR). Participants reported critical gaps in CHD screening, including scarce resources such as a lack of pulse oximeters and echocardiography machines, inadequate training, and overburdened staff struggling with high patient volumes. Emotional distress was common when diagnosing severe CHDs, compounded by parental reluctance due to low awareness and socioeconomic barriers, including costs and travel distances. Operational inefficiencies, such as inconsistent protocols, weak referral systems, and paper-based record-keeping, further delayed diagnoses. Despite these challenges, HPs emphasized the potential of standardized screening tools, interdisciplinary coordination, and community education to improve detection rates. CHD screening in Pakistan is impeded by resource limitations, systemic fragmentation, and sociocultural factors. Prioritizing equipment procurement, HP training, public awareness campaigns, and policy-mandated screening protocols could enhance early detection. Full article

The transition toward sustainable infrastructure in the construction sector necessitates the practical integration of Circular Economy (CE) principles, particularly through the valorization of recycled materials in concrete applications. This review critically synthesizes recent advancements in the use of recycled polyethylene terephthalate (PET), glass powder, and crumb rubber as partial replacements for conventional aggregates in Ordinary Portland Cement (OPC)-based concrete. The incorporation of these secondary materials has demonstrated the ability to reduce the environmental footprint of concrete production—achieving up to 25% reductions in greenhouse gas emissions and diverting significant volumes of waste from landfills—while maintaining structural viability with compressive strength retention levels exceeding 90% in several optimized mix designs. Enhanced ductility, thermal resistance, and reduced density further support their application in specialized construction scenarios. Beyond material characterization, the review systematically examines implementation enablers, including regulatory alignment, life-cycle-based procurement, and design-for-deconstruction strategies. It also highlights critical gaps such as the absence of harmonized standards, variability in recycled material quality, and systemic barriers to market uptake. Addressing these challenges is essential for scaling CE integration and achieving measurable sustainability gains across the built environment. This study aims to inform policy, practice, and research trajectories by linking material innovation with operational frameworks that support regenerative construction systems. Full article

China’s healthcare expenditure tripled during 2010–2019, prompting the nationwide implementation of centralized volume-based procurement (CVBP). While effective in reducing drug prices, CVBP introduces sustainability challenges including supply chain vulnerabilities and welfare trade-offs. This study develops a pharmaceutical sector-embedded computable general equilibrium (CGE) model to quantify CVBP’s multidimensional sustainability impacts. Using China’s 2020 Social Accounting Matrix (SAM) with simulated 10–50% price reductions, key findings reveal that (1) >40% price reductions trigger sectoral output reversal; (2) GDP exhibits an inverted U-shape; (3) household income declines despite corporate/government gains; and (4) industrial contraction impairs innovation capacity and employment stability. Our analysis identifies potential sustainability risks, emphasizing the need for rigorous empirical validation prior to implementing aggressive price reduction policies, and underscores the importance of integrating supply chain considerations into procurement policy design. This approach maximizes resource allocation efficiency while advancing socioeconomic resilience in healthcare systems. Full article

The construction industry continues to generate vast volumes of waste, which harm the environment and negatively impact socio-economic sustainability, especially in a developing country like Saudi Arabia. Prior to investigating effective approaches for managing waste, we must identify the main drivers of construction waste. This paper develops metrics and criteria for identifying and ranking the waste cause factors (WCFs) in the construction of mega-projects in Saudi Arabia. The methodology adopted includes a thorough literature review and a survey ranking waste factors based on a five-point Likert-scale. Data collected from 239 participants across three distinct construction mega-projects were analysed using one-way analysis of variance (ANOVA) with its corresponding post hoc tests, and the identified waste factors were ranked according to their relative importance index (RII). The findings of this study indicate that the main sources of waste in Saudi Arabia involve design changes and complexity, poor project coordination, inefficient waste management systems, lack of supervision, drawing errors, low skill levels among workers and designers, and procurement mistakes. The results and discussions derived from the investigation aim to deepen the understanding of the causes of waste in large-scale construction, which could inform researchers, policymakers, and professionals, whose joint contributions should enable effective waste management strategies in large construction projects. Full article

Background: Volume-based drug procurement is regarded as a pharmaceutical cost-containment measure in healthcare provision globally. The Centralized Volume-Based Drug Procurement (CVBDP) launched in March 2019 in China, also known as the ‘4+7’ policy. 11 cities, including Xi’an city in Shaanxi Province, were set up as pilots. This study aims to examine the intended and unintended impacts of the ‘4+7’ policy on the use of original and generic drugs in city-level and county-level hospitals in Shaanxi, China. Methods: The data used in this study came from the Shaanxi Drug and Apparatus Centralized Procurement Platform (SDACPP). In total, 111,999 drug procurement order records of 118 policy-related drugs (including 25 ‘4+7’ policy-list drugs and 93 alternative drugs by generic name) from April 2017 to November 2019 were included in analyses. Policy-list drugs were divided into bid-winning and non-winning drug products. The volume and the expenditure of the drugs served as the outcome variables, measured by Defined Daily Doses (DDDs) and Chinese yuan (CNY), respectively. A difference-in-differences (DID) approach was used to estimate the policy’s net effect. Results: After the ‘4+7’ policy, the volume of bid-winning, policy-list, and policy-related drugs increased. An unexpected increase in volume was observed among alternative drugs, especially original drugs in city-level hospitals. The expenditure of policy-list and non-winning drugs declined, whereas that of alternative drugs unanticipatedly increased. Changes in volume and expenditure were both greater in generic drugs and in city-level hospitals, compared to their original and county-level hospital counterparts. Conclusions: Our findings highlight the positive effects of the ‘4+7’ policy on generic drug substitution and pharmaceutical expenditure containment, which are greater in city-level hospitals. The unanticipatedly incremental volume of original drugs in city-level hospitals suggests the potential risk of the poor quality of bid-winning drugs, lower compliance with bid-winning drugs among patients, or physicians’ profit-seeking behaviors in urban areas. More regulations and supervisions for the prescription and financial incentives of physicians are needed to address these concerns. Full article

(1) Background: Healthcare is a major contributor to global greenhouse gas (GHG) emissions, especially within the surgical suite. Ophthalmologists play a role, since they frequently perform high-volume procedures, such as cataract surgery. This review aims to summarize the current literature on surgical waste and GHG emissions in ophthalmology and proposes a framework to standardize future studies. (2) Methods: Protocol and reporting methods were based on PRISMA guidelines for scoping reviews. Articles that reported any quantitative measurement of waste or GHGs produced from ophthalmic surgeries were eligible for inclusion. Commentaries, opinion papers, reviews and articles in a non-English language were excluded. (3) Results: A total of 713 articles were reviewed, with 10 articles found to meet inclusion criteria. Six studies produced level 3 evidence, two level 4 evidence, and one level 5 evidence. According to studies, most of the GHGs came from procurement of surgical materials, followed by travel emissions and building energy. (4) Conclusions: Research on waste and GHGs produced in ophthalmic surgery is limited, and existing studies utilize varied approaches to quantify this waste. We propose a standardized waste-lifecycle framework for researchers to organize future research. Such standardization will help in comparing studies and may uncover more opportunities to implement impactful waste reduction strategies in ophthalmology. Full article

Material planning is important in construction, for it affects procurement, cost, and schedule. Proper planning of material supply and logistics helps streamline the performance of all tasks through the avoidance of excessive or insufficient material supply. Material planning relies on quantity takeoff (QTO) and project schedules. Conventionally, quantity takeoff was a manual process based on 2D drawings and human interpretation and was error-prone. Presently, with the popularity of Building Information Modelling (BIM), in BIM-based projects, using inbuilt quantity takeoff functions, quantities of work can be generated automatically from BIM models to aid the quantity takeoff. However, if those inbuilt QTO solutions are object-based, then the quantities of works extracted may not meet the requirements of the users in selected cases, e.g., in zone-based construction projects. Also, for estimating daily material requirements, the accuracy of the quantities of work becomes more important, not only for the purpose of efficient planning but also for reducing construction waste. Since works using the same type of material can go overlapping, in addition to estimating the amount of material for each work, the total amount of material for a day must also be calculated. Thus, this research aims to develop a framework for automatic extraction of zone-based concrete volumes and formwork positions for cast-in-place concrete structures using the data in BIM models, followed by linking them with project schedules for estimating daily concrete and formwork requirements. This framework extends the body of knowledge by introducing an innovative algorithm for automatically calculating overlapped areas between concrete members and a rule for naming tasks in the schedule, followed by evaluating the formwork requirements without drawing formwork in a 3D model. A software tool will be developed to achieve the aim, and a case study will be used to validate the proposed framework. Full article

Background: In northern countries, spring requires the removal of large volumes of abrasive materials used in winter road maintenance. This sweeping process, crucial for safety and environmental protection, has traditionally relied on conventional mechanical brooms. Recent technological innovations, however, have introduced more efficient and environmentally friendly sweeping solutions; Methods: This study provides a comprehensive comparative analysis of the environmental and operational performance of these innovative sweeping systems versus conventional methods. Using simulation models based on real-world data and integrating fuel consumption models, the analysis replicates sweeping behaviors to assess both operational and environmental performance. A sensitivity analysis was conducted using these models, focusing on key parameters such as the collection rate, the number of trucks, the payload capacity, and the truck unloading duration; Results: The results show that the innovative sweeping system achieves an average 45% reduction in GHG emissions per kilometer compared to the conventional system, consistently demonstrating superior environmental efficiency across all resources configurations; Conclusions: These insights offer valuable guidance for service providers by identifying effective resource configurations that align with both environmental and operational objectives. The approach adopted in this study demonstrates the potential to develop decision-making support tools that balance operational and environmental pillars of sustainability, encouraging policy decision-makers to adopt greener procurement policies. Future research should explore the integration of advanced technologies such as IoT, AI-driven analytics, and digital twin systems, along with life cycle assessments, to further support sustainable logistics in road maintenance. Full article

This study evaluates the effects of Christmas melon (Laganaria breviflorus)-based diets on the growth and hematology of African catfish (Clarias gariepinus) after a 6 (six)-month feeding trial. A total of 240 C. gariepinus juveniles with an average weight of 10.68 g were procured from the Fisheries and Aquaculture Department Hatchery Unit for the feeding trial. After acclimating for a week (7 days) using 2.00 mm Coppens feed (45% CP) twice per day, the fish samples were randomly distributed into 12 tarpaulin tanks of 4 ft × 4 ft × 4 ft with a 200 L water holding capacity (four (4) different treatments presented in triplicate). Twenty (20) fish per tank were fed twice daily with the compounded feed with varying dietary inclusion levels of Christmas melon (0% (control), 5%, 10% and 15%). The weights and lengths of the sampled fish were measured biweekly to determine the growth performance, while hematological parameters, such as the packed cell volume, erythrocytes, hemoglobin, and leucocytes were determined midway through and at end of the feeding trial. The data collected were analyzed using ANOVA, and the results revealed the optimum growth and nutrient utilization and hematological and serum biochemical parameters of C. gariepinus in T3. The length–weight relationship results revealed that the fish exhibited an isometric growth pattern with B-values above 3 across the treatments. In conclusion, the results obtained in this study revealed that Christmas melon (L. breviflorus) could replace wheat offal by up to 10% in the diet of C. gariepinus without negative effects on the obtained optimal growth performance, hematological parameters, or serum biochemistry. Full article

Coconut plantations throughout the Asia–Pacific region are generally characterised by the presence of low-productivity senile palms over the age of 60, which have negative impacts on farming communities, coconut processors, and the wider economy. In Fiji, despite numerous senile coconut replacement programs, 60% of coconut palms are considered senile. The purpose of this study is to provide preliminary estimates of the financial viability of a market-based approach to senile coconut palm replacement in Fiji by utilising the palms as a feedstock, for the manufacture of rotary peeled veneer, along with plantation pine and mahogany. A mathematical model capable of supporting deterministic and stochastic dynamic optimisation was developed with an objective function to maximise the gross margin of marketable veneer manufacture per hour ($G{M}_{pz}$) by procuring the optimal allocation of logs throughout the landscape. The majority of facility location and log processing scale scenarios evaluated found that utilising large volumes of senile coconut palms for the manufacture of veneer was optimal, whilst veneering mills situated near the coconut plantations in Vanua Levu were found to maximise $G{M}_{pz}$. Overall, the results indicate that a coconut veneer and engineered wood product (EWP) value chain could present a financially viable opportunity to support large-scale senile coconut palm replacement in Fiji. Full article