Hasil untuk "Production capacity. Manufacturing capacity"

Y. Zhang, M. Dubé, D. McLean et al.

H. Kristinsson, B. Rasco

M. Mehrabi, A. Galip Ulsoy, Y. Koren

Yishi Li, Chunlong Yu

The flexible job shop scheduling problem with job precedence constraints (FJSP-JPC) is highly relevant in industrial production scenarios involving assembly operations. Traditional methods, such as mathematical programming and meta-heuristics, often struggle with scalability and efficiency when solving large instances. We propose a deep reinforcement learning (DRL) approach to minimize makespan in FJSP-JPC. The proposed method employs a heterogeneous disjunctive graph to represent the system state and a multi-head graph attention network for feature extraction. An actor–critic framework, trained using proximal policy optimization (PPO), is adopted to make operation sequencing and machine assignment decisions. The effectiveness of the proposed method is validated through comparisons with several classic dispatching rules and a state-of-the-art DRL approach. Additionally, the contributions of key mechanisms, such as information diffusion, node features, and action space, are analyzed through a full factorial design of experiments.

Ling Zhou, Hongxi Liu, Qinghua Zhang et al.

To improve high-temperature oxidation resistance for Ti6Al4V alloy, Al_xCoCrCu_yFeNi (x = 0, 0.3, 0.5, 0.7, 1.0; y = 1.0, 0.7, 0.5, 0.3, 0, x + y = 1.0) high-entropy alloy (HEA) coatings were prepared on the Ti6Al4V alloy substrate by a laser cladding technique. The results show that the coatings were mainly composed of FCC, BCC, and Ti-rich phases. Severe segregation of the Cu element occurred in the CoCrCuFeNi HEA coatings as a Cu-rich phase (FCC2). The Cu-rich phases decreased with a decreasing Cu content and completely disappeared until the Al content reached 1.0. The microhardnesses of the Cu_1.0, Cu_0.7Al_0.3, Cu_0.5Al_0.5, Cu_0.3Al_0.7, and Al_1.0 HEA coatings were 2.01, 2.06, 2.08, 2.09, and 2.11 times that of the substrate, and compared with those of a Ti6Al4V alloy substrate, the oxidation rates of the HEA coatings decreased by 55%, 51%, 47%, 42%, and 35%, respectively. The surface oxides of the five coatings were mainly composed of CuO, TiO₂, Fe₃O₄, Cr₂O₃, and Al₂O₃. The increase in the Al content promoted the generation of Al₂O₃ film and Cr₂O₃ on the surfaces of the coatings, which significantly improved the high-temperature antioxidant performance of the high-entropy alloy coatings for 50 h at 800 °C. When x = 1.0, the coating showed the best high-temperature antioxidant performance.

Chunling Li, Jun Han

Industrial parks serve as the core spatial units of global manufacturing and energy consumption, and their low-carbon transformation plays a critical role in achieving the “dual-carbon” goals. This study employs a non-oriented Super Slack-Based Measure model under the assumption of non-increasing returns to scale to measure the carbon emission efficiency of 178 national high-tech zones in China from 2008 to 2023. Within the framework of eight integrated economic regions, regional comparison, efficiency rating, and industrial-combination analyses are conducted. The Moran Index is applied to test spatial autocorrelation, while the Geographical Detector and the Multiscale Geographically and Temporally Weighted Regression model are used to analyze the explanatory power and spatiotemporal heterogeneity of driving factors across four dimensions: economic development and industrial structure, technological innovation and research and development, environmental policy and green finance, and human and social development. The results reveal that carbon emission efficiency shows a spatial pattern characterized by higher values in the south and coastal areas and lower values in the west and inland regions. High-efficiency industrial combinations exhibit synergistic enhancement effects, whereas low-efficiency combinations experience efficiency losses. Overall efficiency displays a spatially negative correlation, indicating insufficient diffusion of low-carbon technologies and a noticeable “siphon effect” among neighboring zones. Among endogenous factors, park area and carbon emissions per unit of industrial output are the dominant driving forces, while exogenous factors play a relatively limited role. Variables at the local scale demonstrate high heterogeneity and short response times, suggesting that expanding production capacity should be accompanied by technological progress and the efficient allocation of land and capital to reduce carbon emissions per unit of output. On this basis, differentiated emission-reduction pathways can be designed to promote the coordinated advancement of economic growth and low-carbon transformation.

Chongyang Luo, Yanyan Shao, Zhongwei Jiang et al.

Abstract Fiber‐shaped batteries, distinguished by their unique one‐dimensional architecture, offer ultra‐high flexibility, remarkable stretchability, and excellent knittability, rendering them highly appealing as energy storage solutions for smart wearable fabrics. Among various fiber‐shaped battery systems, aqueous zinc batteries stand out as one of the most promising candidates owing to their high specific capacity, inherent safety, and cost‐effectiveness. However, the practical applicability of fiber‐shaped zinc batteries (FZBs) is significantly hindered by challenges in scalable production, long‐term operational stability, and seamless integration. Despite the growing interest in FZBs, a comprehensive and systematic review that critically examines the essential components, assembly configurations, manufacturing techniques, and performance‐enhancing strategies is still lacking. This review aims to fill this gap by first summarizing the fundamental components of FZBs, including cathodes, anodes, electrolytes, current collectors, and encapsulation materials. It then compares the impact of various assembly configurations, including parallel, winding, coaxial, and weaving structures, on battery performance. Furthermore, it provides an in‐depth analysis of diverse manufacturing techniques for fiber electrodes, including dip‐coating, hydrothermal synthesis, and electrodeposition, as well as the assembly procedures ranging from manual to equipment‐assisted and one‐step assembly methods. In addition, this review highlights strategies for improving both electrochemical and wearable performance through material modification and structural design. It also underscores the multifunctional applications of FZBs, such as thermosensitive, fluorescent, and sweat‐driven variants, along with their potential in physiological sensing and environmental monitoring. Finally, it identifies the existing barriers to FZBs commercialization, including limited energy density, complex integration processes, and unclear internal mechanisms. Based on these insights, it proposes future research directions and development initiatives to advance the field of FZBs, thereby promoting their transition from laboratory prototypes to commercial products.

Fei Li, Wei Xie, Yuanguang Zhong et al.

Capacity configuration and allocation problems in production networks under demand uncertainty have been extensively studied in the literature. In addition to demand uncertainty, capacity risk is also prevalent in practice. This article considers a bipartite production system consisting of multiple plants and a set of customers located in different areas. In particular, these plants will use their configured capacities, facing capacity risk, to serve those customers who have differentiated fill-rate requirements with uncertain demands. Our objective is to optimize capacity configuration and allocation decisions by formulating the problem as a two-stage stochastic program that explicitly incorporates capacity risks and budget constraints. First, we develop a novel “randomized edge-weighted max-flow” priority rule that integrates capacity risk, penalty costs of unmet demands, and allocation costs to allocate the realized capacities to satisfy fill-rate targets, with a tunable parameter introduced to balance service levels and costs. In particular, we derive necessary and sufficient conditions for identifying plants with zero capacities and obtain some practical insights, which can help reduce the potential redundancy of the network system. When partial information and correlation of distributions are known, we implement robust optimization techniques to obtain the ranges of robust capacities under various scenarios. Some practical managerial implications are derived by theoretically discussing the impacts of capacity risk and demand correlations on these ranges. From numerical experiments, we found that the long-chain configuration no longer has the “almost-as-good-as-the-fully-flexible-network” advantage when the capacities are random. In addition, we also investigate the impacts of correlations among realized capacities or demands on the associated flexibility. Finally, some interesting and useful insights for practitioners can be obtained by analyzing the impacts of costs, fill rates, and uncertainty on the total optimal capacity and total configuration cost.

Mohammad Taghi Ghashghaei, Ayoub Ahmadi Mousa Abad, Mohammad Taleghani

Abstract The aim of the current research is to provide a model to explain the effect of internal and external organizational decision components on the cost price of industrial products with a factor-based approach. The research method is applicable in terms of its purpose, and, a kind of qualitative and quantitative research of an exploratory type in terms of the process. The statistical population of the research is all experts and informants of the cost price of industrial products, and 35 people were determined as the sample size by the snowball sampling method. Companies' databases such as data related to industrial production and product pricing were used to collect data. Three methods of theme analysis, Delphi technique and factor-based model were used to analyze the data. The software used for the Delphi technique was SPSS version 25, and Netlogo software was used for the implementation and simulation of the factor-based model and its validation. The findings show that the changes in each factor during the period under review have an effect on other factors in the final price, and at the end, the validity of the model was confirmed by the experts. Therefore, the integration of the theory of constraints with factor-based modeling can be used as an effective tool in the cost price of manufactured products, and by means of it, the appropriate selling price of products can be determined and predicted in the short and long term periods. Extended Abstract Introduction From a long time ago, information has been very important in the process of conscious and enlightened human decision-making. With the development of societies, the importance of information in decision-making has increased. Today, information is considered as one of the important indicators of the strength of societies and their sustainable development. Accounting is a process that creates financial information, and in all economic units, an important part of decisions is made based on this information. Currently, accounting knowledge has become a comprehensive knowledge that many feel themselves obliged to know (Wu & et al, 2023). The need for accounting information has grown significantly in recent years. This growth has been due to the decrease in the cost of using computers as well as the increase in the use of scientific and complex methods for planning and decision making. Therefore, managers need more than ever the detailed accounting information, especially information related to the cost price. This growing need for accounting information is to meet internal organizational needs and also prepare financial reports for interest groups outside the business unit (Bloze, 2022).  In order to achieve this goal, managers must have accurate and timely information about the limitations in the system, the cost price of each product, and the available solutions for the optimal use of these limitations. Management accounting as a system must provide this information for managers (Hook, 2022). The traditional management accounting system and the developments in it, such as activity-based costing as well as the theory of constraints solutions, have been able to provide the aforementioned information well (Seyedy & et al, 2021). One of the most flexible modeling methods is factor-based or factor-oriented modeling. The basis of naming this method is because the agents play an essential role in the model. In this type of modeling, each of the real world agents play a role as decision-making and fully automatic entities called model agents. In this regard, the aim of the current research is to answer this main question: what is the presentation of the simulation model of internal and external organizational decision components in improving the cost price of industrial products based on the factor-based approach? Theoretical Framework Internal decisions  Internal decisions in every organization are prepared by the senior managers of the organization periodically, often monthly. These reports are prepared on the way the organization works, including the cost price of products, material consumption, purchase reports and other important reports on industry and production trends. Intra-organizational decisions can be considered as types of management reports; because these reports are presented to the managers for detailed analysis and financial performance of the organization. (Junner, 2010) External decisions  Extra-organizational decisions mean a type of report that is exposed to the observation of others after the approval and review of the organization's managers. These reports examine the financial conditions of the organization in general. Reports such as financial statements, profit and loss, balance sheet, etc. are such reports that generally examine financial accounts. These reports are not entered with the details of the smaller parts of the organization such as production and materials, etc. (Liang, 2019). The cost price of industrial production Manufacturing/industrial/commercial companies usually have many side costs that have a significant impact on the process of determining the price of a product. In other words, organizations have direct and indirect costs that can affect the cost price of products. Cost price accounting (cost accounting) is the process of collecting information about the costs incurred by a company's activities. Cost price accounting is a type of management accounting whose purpose is to calculate the total production costs of a company by evaluating the variable costs of each stage of production as well as fixed costs (such as rental costs) and is necessary to maintain a stable level of profit in the short and long term. North, 2019) Factor-based simulation model  One of the most flexible modeling methods is factor-based modeling. The basis of naming this method is because the agents play an essential role in the model. In this type of modeling, each of the agents of the real world is called a model agent as a fully automatic decision-making entity. Each of these agents has various parts to understand the environment, analyze it, and finally take action. In fact, in factor-based modeling, the decision-making process in the real world is tried to be simulated by similar factors. (Hader, 2018) Research methodology According to the goals it pursues, the present research is a type of applicable research, and in terms of the process of conducting research places in the field of qualitative and field research, of an exploratory type. The statistical population of the research is all experts and informants of the cost price of industrial products, selected by the snowball sample. The experts' criteria included having a management experience in cost accounting for more than 5 years, and having a master's degree or higher. In this research, 10 people were determined as the sample size. In order to collect data from the companies' databases, data related to industrial products and their pricing were extracted to check the research objectives. Three methods of theme analysis, Delphi technique, and factor-based model were used to analyze the data. Netlogo software was used to implement and simulate the agent-based model and validate it. Research findings The findings show that during different years from 2022 to 2024, any changes in endogenous and exogenous variables have a direct relationship with each other; and the cost price also decreases and increases with the decrease and increase of these costs. The behavior of agents during different changes in the final price of products shows fluctuations. Based on the findings, it can be stated that the endogenous variables are: marketing, advertising, distribution and sales, transportation, manpower, construction overhead, investment, profit, volume and number of sales, pricing, depreciation cost, production capacity, consumed energy, and quantitative discounts; and also exogenous variables include: technology level, inflation, taxes and tolls, market competition, exchange rate, bank interest rate, possible license fees, union rules and regulations, import and export amount, market demand, price of energy carriers, price of raw materials, nature of the market, price of competitors, boom or bust of the market, price elasticity, and substitute goods. Cost accounting information is designed for managers. These findings are in agreement with the research results of Omran (2020) and Over & et al (2021) in the components of construction overhead, investment, profit; of Jamz & Kolz (2021) and Rota & Soza (2021) in the price components and depreciation costs, of Seyedy & et al (2021) in the price components of energy carriers, and the price of raw materials, and of Kadim & et al (2020) and Paro & et al (2019) in the price components of competitors, the boom or bust of the market. Conclusion According to the findings of the research, the following suggestions can be made: 1- It is suggested to gather information about competitors and inter-task coordination by monitoring as much as possible, and by analyzing the strengths and weaknesses of competitors, they will become more profitable and, as a result, perform better. 2- Cost reduction will not be possible except by redesigning the product. In this technique, before the production stage, attention is paid to cost management to produce a product with a predetermined cost price and at the same time provide the desired profit of the management. 3- In costing, first the price is determined based on market analysis, and then the cost price of the product is determined according to the expected profit of the company. 4- Determining the selling price of products should be variable according to the amount of customers' orders to help increase the profitability of the company while being competitive 5- Establishing a strategic supply chain with raw material suppliers will reduce the initial production costs and ultimately reduce the cost price. 6- Creating an integrated software enable to connect all the separate softwares together and prevent the entry of new and parallel information has a significant effect on increasing the precision and accuracy of cost price calculations in the industry. Researchers can also use other methods to model and compare the results, such as fuzzy dynamic systems, structural and interpretive modeling, simulation algorithms, dynamic non-cooperative game theory, etc.

Mingxin Sang, Nan Pan, Jingna Wu et al.

Omega-3 fatty acids are in high demand due to their efficacy in treating hypertriglyceridemia and preventing cardiovascular diseases. However, the growth of the industry is hampered by low purity and insufficient productivity. This study aims to develop an efficient RP-MPLC purification method for omega-3 fatty acid ethyl esters with high purity and capacity. The results indicate that the AQ-C18 featuring polar end-capped silanol groups outperformed C18 and others in retention time and impurity separation. By injecting pure fish oil esters with a volume equivalent to a 1.25% bed volume on an AQ-C18 MPLC column using a binary isocratic methanol–water (90:10, <i>v</i>:<i>v</i>) mobile phase at 30 mL/min, optimal omega-3 fatty acid ethyl esters were obtained, with the notable purity of 90.34% and a recovery rate of 74.30%. The total content of EPA and DHA produced increased from 67.91% to 85.27%, meeting the acceptance criteria of no less than 84% set by the 2020 edition of the Pharmacopoeia of the People’s Republic of China. In contrast, RP-MPLC significantly enhanced the production efficiency per unit output compared to RP-HPLC. This study demonstrates a pioneering approach to producing omega-3 fatty acid ethyl esters with high purity and of greater quantity using AQ-C18 RP-MPLC, showing this method’s significant potential for use in industrial-scale manufacturing.

S. Silva Sajin Jose, Santosh Kr. Mishra, Ram Krishna Upadhyay

Additive manufacturing has witnessed significant growth in recent years, revolutionizing the automotive and aerospace industries amongst others. Despite the use of additive manufacturing for creating complex geometries and reducing material consumption, there is a critical need to enhance the mechanical properties of manufactured parts to broaden their industrial applications. In this work, AISI 316L stainless steel is used to fabricate parts using three different strategies of the additively manufactured Laser Powder Bed Fusion (LPBF) technique, i.e., continuous, alternate, and island. This study aims to identify methods to optimize grain orientation and compaction support provided to the material under load, which influence the frictional and wear properties of the manufactured parts. The load-bearing capacity is evaluated by measuring the frictional and wear properties. The wear patch track is also examined to establish the physical mechanisms at the surface interface that lead to the smooth transition in response to the load. Grain orientation is compared across different strategies using Electron Backscatter Diffraction (EBSD) maps, and the influence of surface roughness on sliding behavior is also evaluated. The results demonstrate that the island scanning strategy yields the best performance for load-bearing applications, exhibiting superior grain orientation and hardness in the additively manufactured parts.

Shabibi Sara Abdullah Said Al, Balus Shima Mohammed Abdul Sattar Al, Kuckian Sachin et al.

Concrete is a major concern for engineers because of its extensive use in the building sector. The production of concrete also uses a lot of materials all around the world. However, the price of energy, the expansion of manufacturing capacity, and environmental concerns are three of the most crucial factors to consider in the concrete industry, considering the fast urbanisation and modern market. Because of issues with pollution and the high price and low availability of sand and cement, the current research focuses on employing marble powder as a cement substitute and iron ore as a sand substitute. The commercial by-products of producing and polishing granite powder, waste iron powder (WIP) and waste marble powder (WMP), are mainly wasted and pose a threat to human health. Substituted with marble powder (5% and 10%) for the cement and iron powder (30%, 40%, and 50%) for the fine aggregate. The results were based on the material's compressive strength, flexural strength, and workability. The highest compressive and flexural strengths were achieved when 10% of the cement was replaced with marble powder and 50% of the iron ore was replaced with sand. According to the results, the strength qualities of concrete might be enhanced by using less marble and more iron ore. From both a financial and ecological perspective, recycling these components and incorporating them into concrete as a partial replacement makes sense.

Yuri Laio Teixeira Veras Silva, Nathállya Etyenne Figueira Silva

The Cardinality-Constrained Portfolio Selection Problem (CCPSP) consists of allocating resources to a limited number of assets. In its classical form, it is represented as a multi-objective problem, which considers the expected return and the assumed risk in the portfolio. This problem is one of the most relevant subjects in finance and economics nowadays. In recent years, the consideration of cardinality constraints, which limit the number of assets in the portfolio, has received increased attention from researchers, mainly due to its importance in real-world decisions. In this context, this paper proposes a new hybrid heuristic approach, based on a Non-dominated Sorting Genetic Algorithm with Local Search structures, to solve PSP with cardinality constraints, aiming to overcome the challenge of achieving efficient solutions to the problem. The results demonstrated that the proposed algorithm achieved good quality results, outperforming other methods in the literature in several classic instances.

Manish V. Mehta, Mrunalkumar D. Chaudhari, Rakesh Chaudhari et al.

This article presents a comprehensive study on the application of Hastelloy C-22 powder weld overlay on SA 240 Type 316L austenitic stainless steel using the laser beam welding process. This novel combination of materials and processes was investigated for the first time, focusing on its potential utility for various industrial applications. Various testing techniques, including visual testing, hardness testing, bend testing, chemical composition analysis using optical spectroscopy, corrosion resistance assessment through the potentiodynamic polarization technique, and macro- and microstructural observation, were employed to evaluate the performance of the weld overlay. The research findings had several significant outcomes. Notably, precise control and minimal alloy mixing were achieved, as evidenced by the dilution at a remarkable height of 0.5 mm from the base metal. The laser welding process resulted in a minimal heat-affected zone and a fine columnar interdendritic microstructure, with average primary and secondary arm spacing values of 3.981 µm and 2.289 µm, respectively. Rigorous visual and bend testing confirmed the integrity of the sound welds in the overlay. Moreover, the high-quality finish of the weld overlay eliminated the need for extensive machining and finishing processes, resulting in cost reductions. This study also demonstrated primary and secondary inter-laminar spacing, leading to improved overall structural integrity. Additionally, the weld overlay exhibited excellent hardness characteristics. The current work contributes to the advancement of welding processes and provides practical solutions to enhance efficiency, cost-effectiveness, and structural performance in relevant industrial applications.

Nikita Gandhi, Rob Rose, Anthony J. Croxford et al.

Non-destructive testing (NDT) is a quality control measure designed to ensure the safety of products according to established variability thresholds. With the development of advanced technologies and a lack of formalised knowledge of the state-of-the-art, the National Composites Centre, Bristol, has identified that the increasing complexity of composite products will lead to some severe inspection challenges. To address the apparent knowledge gap and understand system complexity, a formulaic approach to introduce intelligence and improve the robustness of NDT operations is presented. The systemic development of a high-fidelity knowledge base (KB) involves the establishment of a capability matrix that maps material, component, and defect configuration to the capabilities and limitations of selected detection methods. Population and validation are demonstrated through the experimental testing of reference standards and evaluated against an assessment criteria. System complexity in ultrasonic testing operations focusses on capturing the inherent risks in inspection and the designation of evidence-based path plans for automation platforms. Anticipated deployment of the validated applicability data within the KB will allow for road-mapping of the inspection technique development and will provide opportunities for knowledge-based decision making. Moreover, the KB highlights the need for Design for Inspection, providing measurable data that the methodology should not be ignored.

Andreas Borowski, Benjamin Gröger, René Füßel et al.

Deformation of continuous fibre reinforced plastics during thermally-assisted forming or joining processes leads to a change of the initial material structure. The load behaviour of composite parts strongly depends on the resultant material structure. The prediction of this material structure is a challenging task and requires a deep knowledge of the material behaviour above melting temperature and the occurring complex forming phenomena. Through this knowledge, the optimisation of manufacturing parameters for a more efficient and reproducible process can be enabled and are in the focus of many investigations. In the present paper, a simplified pultrusion test rig is developed and presented to investigate the deformation behaviour of a thermoplastic semi-finished fiber product in a forming element. Therefore, different process parameters, like forming element temperature, pulling velocity as well as the forming element geometry, are varied. The deformation behaviour in the forming zone of the thermoplastic preimpregnated continuous glass fibre-reinforced material is investigated by computed tomography and the resultant pulling forces are measured. The results clearly show the correlation between the forming element temperature and the resulting forces due to a change in the viscosity of the thermoplastic matrix and the resulting fiber matrix interaction. In addition, the evaluation of the measurement data shows which forming forces are required to change the shape of the thermoplastic unidirectional material with a rectangular cross-section to a round one.

Ali Motevali, Ali Mobini Dehkordi, Hossein Sadeghi

The need to transition to an economic system that does not exceed environmental constraints requires a great deal of effort to address sustainability issues. In this regard, the circular economy model is expanding at political, commercial, and academic levels. The present study aimed to identify and analyze the factors influencing the entrepreneurial ecotourism based on circular economy. Having retrieved a total of 152 articles from the Google Scholar database, the study applied various filters and identified the most relevant articles (i.e., 14 items) regarding title, abstract, methodology, and article text. A meta-synthesis approach was used to analyze the articles, which led to the identification of 62 open codes and, at a higher level, seven core codes. The extracted categories were finally categorized under three stages: pre-circulation (empowerment and value creation), circulation (technology and biocentrism), and post-circulation (recycling and continuity).IntroductionDespite being classified as a service sector that produces intangible services, tourism relies on vast amounts and flows of inexhaustible natural resources. However, it largely reflects a linear production model (Manniche et al., 2021), which is based on a linear model of production and consumption, namely extraction/production and consumption/disposal, which depletes natural resources and produces waste. The current linear economy neither optimizes the use of materials nor promotes recycling and reuse of waste. Therefore, policymakers and stakeholders worldwide have increasingly focused on the concept of circular economy (CE). However, much of the CE literature has been developed mainly for the manufacturing sector, with only a limited number of sources devoted to the tourism sector, where massive consumption of energy and water, food waste, congestion problems, and CO2 emissions are prevailing (Rodríguez et al., 2020). Nonetheless, there is a growing focus on CE in order to address sustainability challenges. CE is emerging as a transformational model with economic, environmental, and social benefits (Clube & Tennant, 2020). It is gaining popularity in academia, industry, and policymaking as an alternative model that reduces resource consumption and minimizes greenhouse gas emissions. Business models are essential for implementing this concept at the organizational level (Geissdoerfera et al., 2020). However, there are very few documented initiatives on CE in the tourism industry, and this area has yet to be fully explored. CE is considered a relatively new paradigm that can contribute to a more sustainable tourism industry. In this respect, the tourism industry is worthy of further attention since it plays an essential role in economic transformation due to its multiplier effect on the whole economy and its capacity to encourage cyclical flows among suppliers and customers.Materials and MethodsThe current study is a qualitative research based on the meta-synthesis approach which involves examination of the data and findings extracted from other qualitative studies related to a research topic. It is worth noting that meta-synthesis is not the same as a comprehensive review of the qualitative literature. In meta-synthesis, the secondary and primary data analysis is applied not to the studies themselves but to their findings, so it involves combining interpretations of the primary data from the selected studies. This approach focuses on qualitative studies that do not necessarily cover a broad theoretical basis and, instead of providing a comprehensive summary of the findings, creates an interpretive synthesis of the findings (Zimmer, 2006). The sample of the present study consisted of a number of qualitative studies selected according to their relevance to the research question (Walsh & Down, 2005). Having retrieved a total of 152 articles from the Google Scholar database, the study applied various filters and identified the most relevant articles (i.e., 14 items) regarding title, abstract, methodology, and article text. They were then analyzed through a meta-synthesis approach, leading to the identification of several themes and categories.Results and DiscussionThe extracted categories were categorized under three stages: pre-circulation (empowerment and value creation), circulation (technology and biocentrism), and post-circulation (recycling and continuity).ConclusionThe primary purpose of this study was to identify and analyze previous research in the field of CE and its relationship with the tourism industry. Based on the analysis of the relevant articles, the extraction categories were categorized under three stages: pre-circulation (empowerment and value creation), circulation (technology and biocentrism), and post-circulation (recycling and continuity). The research findings suggest that developing the tourism industry based on CE approach is considered essential for sustainable growth and development of regions. The industry’s evolution towards CE to minimize its environmental footprint is of great importance. Circular tourism emphasizes the reuse of goods and waste recycling, and considers the use of second-hand rental goods and facilities as a valuable measure. In circular tourism, unlike linear tourism, the tour process does not end with the completion of the tour but enters the post-tour stage, which is as important as the tour stage. Compared to previous research, the present study is innovative in both practical and theoretical aspects. It is innovative in terms of research because it is one of the first studies in Iran to address the issue of the entrepreneurial ecosystem in the tourism industry with an emphasis on CE. Secondly, it looked at the conditions and advantages of tourism from an ecosystem perspective. The research findings can be useful for policymakers concerned with improving competitiveness and creating a conducive environment for entrepreneurial businesses. The novelty of this study lies in the contribution it makes by providing the relevant policymakers with a refined and new insight into the topic.

Li Li, Yong Wang, Kuo-Yi Lin

Simon Davidsson Kurland

Estimates of energy use for lithium-ion (Li-ion) battery cell manufacturing show substantial variation, contributing to disagreements regarding the environmental benefits of large-scale deployment of electric mobility and other battery applications. Here, energy usage is estimated for two large-scale battery cell factories using publicly available data. It is concluded that these facilities use around 50–65 kWh (180–230 MJ) of electricity per kWh of battery capacity, not including other steps of the supply chain, such as mining and processing of materials. These estimates are lower than previous studies using data on pilot-scale or under-utilized facilities but are similar to recent estimates based on fully utilized, large-scale factories. The environmental impact of battery manufacturing varies with the amounts and form of energy used; especially as renewable sources replace electricity from fossil fuels. As additional large-scale battery factories are taken into use, more data should become available, and the reliance on outdated, unrepresentative, and often incomparable, estimates of energy usage in the emerging Li-ion battery industry should be avoided.

Yun-Sik Jin, C. Cho, Daejong Kim et al.

We report on the mass production of plasma activated water (PAW) by a non-thermal atmospheric pressure plasma. As a non-thermal plasma source, we used planar dielectric barrier discharge (DBD) and two types cylindrical DBDs. The manufacturing characteristics of PAW were investigated for each DBD type. The results show that the radical transfer characteristics from plasma to water have a dominant effect on the PAW properties. Of the two cylindrical DBD reactors, the “direct” type in which the mesh electrode was replaced with the conductor (Al) showed superior characteristics over “indirect” type. DBD reactor with an Al electrode with the length of 1 m long achieved a PAW production capacity of 520 liters per hour and production efficiency of 65 l kWh−1. Such a large-capacity PAW manufacturing device can be applied to various industries including agriculture, sterilization, and water treatment.