With the progress of new trends of society, gymnasium, the most important part in Chinese sports facility, can not only meet the needs of physical exercise of students, but also provide a favorable place for social we...With the progress of new trends of society, gymnasium, the most important part in Chinese sports facility, can not only meet the needs of physical exercise of students, but also provide a favorable place for social welfare development. But due to the influence of traditional management methods, some problems are still seen in the process of operation of university gymnasiums in china, which restricts the overall development of our country's sports enterprise. Therefore, this paper probes into the study on disadvantageous existed conditions and analyzes the operation strategies and management strategies of university gymnasiums on the basis of their characteristics and advantages.展开更多
Plant maintenance has been a discipline that has gradually evolved with the industrial revolution. For quite some time, it has been a "necessary evil" in production, manufacturing, and process settings. The changing...Plant maintenance has been a discipline that has gradually evolved with the industrial revolution. For quite some time, it has been a "necessary evil" in production, manufacturing, and process settings. The changing business needs and industrial conditions have had various impacts on the maintenance process, particularly over the last few years. While some industries have inherent difficulties seeing what maintenance is all about, others have begun to add more flavor to the organizational maintenance practices. This article brings an overview of developments within the offshore oil and gas production sector.展开更多
Aircraft on ground or down-time for its maintenance is a clear loss in revenue for an airline operation. With never ending competition and growing operating costs of aircraft, airlines continuously need to explore opp...Aircraft on ground or down-time for its maintenance is a clear loss in revenue for an airline operation. With never ending competition and growing operating costs of aircraft, airlines continuously need to explore opportunities to reduce the aircraft down-time in order to remain sustainable. Due to round the clock operation feature of scheduled airlines, aircraft maintenance operations are generally carried out using traditional management methodologies instead of considering it as a project. Though aircraft heavy maintenance checks consist of several major tasks that can last from few weeks to a year, the maintenance organisations do not adopt modern project management methodologies. Therefore, this paper models a heavy maintenance check of an Airbus aircraft as a typical project and adopts contemporary project management methodology to explore the possibility of reducing the downtime. To this end, a case study has been done at an aircraft maintenance company to analyse the potential of this project management method in aircraft maintenance industry.展开更多
An operation strategy of the electric vehicle (EV) battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and ...An operation strategy of the electric vehicle (EV) battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and the possible mutual actions between battery charging and swapping. Three energy management strategies can be used in the station: charging period shifting, energy exchange between EVs, and energy supporting from surplus swapping batteries. Then an optimization model which minimizes the total energy management costs of the station is built. The Monte Carlo simulation is applied to analyze the characteristics of the EV battery charging load, and a heuristic algorithm is used to solve the strategy providing the relevant information of EVs and the battery charging and swapping station. The operation strategy can efficiently reduce battery charging during the high electricity price periods and make more reasonable use of the resources. Simulations prove the feasibility and rationality of the strategy.展开更多
Currently,the investment of oil and gas industry is still facing an unfavorable environment,in which,instable factors,such as financial crisis,terrorist,religious conflicts and rigorous environmental regulations,keep ...Currently,the investment of oil and gas industry is still facing an unfavorable environment,in which,instable factors,such as financial crisis,terrorist,religious conflicts and rigorous environmental regulations,keep mucking up the business all around the world.Meanwhile,China’s rapid energy consumption growth boosted by a booming economy has put the country to rely heavily on exported oil.It is therefore extremely urgent to expand and diversify petroleum supply channel in consideration of the country’s energy security.As the world’s economy has been slowly recovering from the slump and展开更多
Generically, SCM may be said to include all activities carried out to ensure proper functioning of the supply chain. The activities included in proper management of a supply chain broadly include logistics activities,...Generically, SCM may be said to include all activities carried out to ensure proper functioning of the supply chain. The activities included in proper management of a supply chain broadly include logistics activities, planning and control of the flow of information and materials in a firm, management of relationships with other organizations and government intervention, However, crude oil theft and pipeline vandalism are established products supply chain disruptors in Nigeria which are rendering the task of running an efficient petroleum supply chain onerous. This paper aims to establish the importance of effective supply chain strategies for companies in the oil and gas industry with special focus on the Nigerian oil and gas sector and the strategies by which the state oil and gas corporation in this sector may mitigate disruptions to its supply chain. This study investigates the enhancement of supply chain strategies towards meeting the challenge of crude oil theft and pipeline vandalism, using the Nigerian National Corporation (NNPC) as a case study. Based on this study, data were collected from two sources: A summary of incident reports obtained from NNPC and an interview with personnel in the PPMC Department. Incident report refers to a report produced when accidents such as equipment failure, injury, loss of life, or fire occur at the work site. Content analysis is utilized to evaluate data obtained from interview responses, CBN financial stability reports, NDIC annual reports, circulars, banking supervision reports and implementation guidelines. The study found out that NNPC should endeavor to sustain its value chain and ward of pipeline vandals and crude oil thieves by engaging in community partnership, detailing security outfits to ensure its pipelines’ right of way and bridging. Concluded that the oil supply chain of the Nigerian National Petroleum Corporation has been plagued by disruptions in the form of crude oil theft and pipeline vandalism which has had debilitating effects on its value.展开更多
This paper is aiming to connect previous research in global competitiveness analysis, taking the impact of the global financial crisis into account, to evaluate how manufacturing companies are able to manage crisis by...This paper is aiming to connect previous research in global competitiveness analysis, taking the impact of the global financial crisis into account, to evaluate how manufacturing companies are able to manage crisis by adjusting their manufacturing strategy and transformational leadership together with technology level to improve their global operational competitiveness performances. Based on the previous research, we developed a theoretical approach of modeling the core factors which influence the operational competitiveness performance (i.e., manufacturing strategy and transformational leadership with technology level), into conceptual analytical models to evaluate overall competitiveness. The empirical studies are focused on manufacturing companies in China, Finland, Slovakia, Iceland, and Spain. The case companies are evaluated with the proposed analytical models and their performances are compared in global context to conclude the experience of crisis management.展开更多
In the current socialist market economy,if an enterprise wants to grow and develop,it must do all kinds of management for its enterprise,and the most important thing for strengthening management of enterprises is to s...In the current socialist market economy,if an enterprise wants to grow and develop,it must do all kinds of management for its enterprise,and the most important thing for strengthening management of enterprises is to strengthen their own operation and management abilities.Whether it is financial management,management of personnel efficiency,or management of talents,it is necessary to protect from the infrastructure,so as to fundamentally improve the economic benefits of the enterprise,and vice versa if社is not properly managed,it will affect the development of the enterprise.Therefore,improving the operation and management abilities of enterprises at present is an important factor to promote the economic development of enterprises.This paper analyzes the management problems of enterprises and the definition of enterprise operation and management abilities,and analyzes how enterprises can reform and innovate,thus strengthening the operation and management abilities and economic benefits of enterprises.展开更多
Today, in the modern era, and under the pressure of rapid development around the kingdom regions, electric utilities are confronted with a myriad of challenges that include aging infrastructure, enhanced expectation o...Today, in the modern era, and under the pressure of rapid development around the kingdom regions, electric utilities are confronted with a myriad of challenges that include aging infrastructure, enhanced expectation of reliability, reduced cost, and coping effectively with uncertainties and changing regulation requirements. Indeed, for distribution systems, HV/MV substations represent a complex and critical physical asset that requires a careful evaluation of their maintenance practices aiming at more cost-effective tasks. The first concern of the electric power distribution company in Morocco is the optimization of the distribution network maintenance scheduling, to minimize system operating costs and ensure that the system is running most economically. There is significant pressure on power providers for greater system reliability and improvement of customer satisfaction, while similar emphasis is placed on cost reduction. These cost reductions focus on reducing operating and maintenance expenses, and minimizing investments in new plants and equipment. However, the present of the electricity distribution, influenced by a number of technical restrictions and strict regulatory requirements to meet, leads distribution utilities to search new ways of optimizing the maintenance management, make an effort to maximize profit by reducing their electricity supply and operation costs while maintaining their reliability, developing more effective activities, with lower costs. Furthermore, maximal HV/MV substation asset value and minimal maintenance cost are typical economic objectives of the electric utilities. The optimization of maintenance is one possible technique to reduce maintenance costs while improving reliability and utilities need to implement new strategies for more effective maintenance techniques and Asset Management (AM) methods programs to manage inspections and maintenance activities in order to control HV/MV substation equipment conditions. However, development of strategies to make sound decisions in order to effectively improve equipment and system reliability while meeting constraints such as a maintenance budget is a challenge. Finally, this paper describes the application of a new approach based Reliability Centered Maintenance (RCM) methodology to optimize maintenance resources and to the development of maintenance plan for HV/MV distribution substations. For this purpose, a case study was performed on the equipment of power distribution systems for the benefit of a holding company (ONEE Electricity Distribution) in Morocco. The present study was conducted in Oujda Exploitation Maintenance Service (OEXMS), in charge of operation and maintenance of distribution networks.展开更多
This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable ene...This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable energy and reduce the cost of investment and operation. Next, the problems in the optimal planning for a stand-alone microgrid system are summarized, including the unique operational control targets, the flexible combination approaches and the operation strategies of distributed generation energy supply system, and the special requirements of the reliability of power supply quality factor from the different users. And then, centering on the operational control and the advanced energy management strategy, the optimal mathematical models and the solving methods, the reliability assessment approaches and the improvement measures of a stand-alone microgrid system, an overview of the general situation of the recent research at home and abroad and the limitations of the study are summarized. Finally, several problems, existing in the optimal planning of stand-alone microgrid system, to be urgently solved, are put forward.展开更多
Kabul New City is a new capital development and a modern city development of Afghanistan covering total area of 740 km<sup>2</sup>. In 2009 Afghan cabinet approved developing New Capital to fulfill the req...Kabul New City is a new capital development and a modern city development of Afghanistan covering total area of 740 km<sup>2</sup>. In 2009 Afghan cabinet approved developing New Capital to fulfill the requirement of growing population. For sustainable development, it has been planned to have a green belt and central park about 1298 hectares within the city. It is having positive impact on human health along with the economic, social and environmental benefits. Hence, for sustaining the urban parks, their proper maintenance is a foremost problem. The solid waste management is duly considered in planning stage of development, otherwise, it would encounter major challenges during operation and maintenance of Park. The projected waste generation in KNC park area is required to be assessed, therefore, surveys of Bagh-e-Babur in existing Kabul are carried out for the visitors’ projection and solid waste generation. The highest visitors and waste were estimated in declining order of summer, spring, fall, and winter. Kabul New City Central Park results speculate that the total visitors’ projection is going to be 6,745,313 per year generating about 337 metric tons wastes/year (0.05 kg/visitor/day). 10 Vehicles of capacity 8 m<sup>3</sup> are required to collect waste from central park towards the Transfer Station while 4 vehicles of 23 m<sup>3</sup> are required for collection of waste from TS to Landfill. Moreover, 700 containers of 240 liters are required in the park. Furthermore, different sites were indicated in map for composting area where after the development it would be considered.展开更多
The effective cathode flow field design can realize the internal water balance and higher current density output of proton exchange membrane fuel cells(PEMFC).Therefore,a segmented water management flow field is propo...The effective cathode flow field design can realize the internal water balance and higher current density output of proton exchange membrane fuel cells(PEMFC).Therefore,a segmented water management flow field is proposed in this study,i.e.a half separated-half coupled cathode(HSHC)flow field which has two inlets but just one outlet.A 3D numerical PEMFC model is applied to study the effect of the HSHC flow field on PEMFC performance and its operating strategy in terms of operating conditions.The study results are shown as follows:Compared with the two conventional cathode flow fields,the HSHC flow field improves the water balance along the channel and increases the current density by 17.1%at a cathode stoichiometry of 3.25.It is because the HSHC flow field can overcome the water loss at channels upstream and the water accumulation at channels downstream.The draw water phenomenon(DWP)in the HSHC flow field is observed,which is mainly affected by the water vapor pressure of channel.Based on the DWP,cooling channel inlet flow rates can be used to adjust water balance,but severe water loss should be avoided.In addition,the inlet temperature control in HSHC flow field should be that cell temperature>cathode channel inlet temperature>cooling channel inlet temperature>ambient temperatures for better water balance.展开更多
This paper explores the operational strategies of cross-border micro, small, and medium enterprises (MSMEs). Against the backdrop of globalization and digitalization, cross-border trade has become one of the important...This paper explores the operational strategies of cross-border micro, small, and medium enterprises (MSMEs). Against the backdrop of globalization and digitalization, cross-border trade has become one of the important pathways for many MSMEs to achieve growth and competitive advantage. Firstly, the paper outlines the concept and characteristics of cross-border MSMEs, as well as the analysis of their operational environment in the context of globalization, including political, economic, social, technological, environmental, and legal factors. Secondly, the paper proposes operational strategies for cross-border MSMEs, including international market selection and positioning, cross-border marketing strategies, supply chain management, cross-border financial management, and cross-border risk management. Finally, the paper summarizes the importance of effectively implementing these strategies for cross-border MSMEs to seize international market opportunities, reduce operational risks, and enhance competitiveness and profitability.展开更多
The topic investigated competition in marketing as a survival yardstick for small and medium enterprises (SMEs) in Nigeria. The objectives addressed by this study were: (1) identifying different types and intensi...The topic investigated competition in marketing as a survival yardstick for small and medium enterprises (SMEs) in Nigeria. The objectives addressed by this study were: (1) identifying different types and intensity of competition that SMEs are exposed to along the life-cycle portfolio in Nigeria; (2) quantifying the strength of SMEs vis-a-vis some foreign enterprises in terms of market competition; and (3) proffering solutions on how best they could match competitively these foreign enterprises. Relevant models and theories were employed in literature to evolve detailed analysis of issues relating to the variables used in terms of competition in marketing and survival of juice-producing SMEs. Two hypotheses were investigated through the survey of 20 prominent Ikeja based SMEs using Cluster sampling, 5-points Likert summated rating scale was adopted, while Yard's formula with 95% confidence level and 5% error tolerance was used. Alternative form validity of the instrument was measured at 0.63 while its reliability was measured at Cronbach's alpha of 0.70. Pearson's product-moment correlation was used in testing hypothesis 1 while standard multiple regressions were used to test hypothesis 2. Findings revealed that there was strong relationship between survival of juice-producing SMEs with forms of competition on a firm's life-cycle; while competition had positive effects on survival components for the enterprises. It was concluded that since competition subsists in any firm's life-cycle, strategies to support operations for survival must be adopted. It was recommended that operators of SMEs have to monitor and manage competition as it affects their businesses positively and/or negatively.展开更多
文摘With the progress of new trends of society, gymnasium, the most important part in Chinese sports facility, can not only meet the needs of physical exercise of students, but also provide a favorable place for social welfare development. But due to the influence of traditional management methods, some problems are still seen in the process of operation of university gymnasiums in china, which restricts the overall development of our country's sports enterprise. Therefore, this paper probes into the study on disadvantageous existed conditions and analyzes the operation strategies and management strategies of university gymnasiums on the basis of their characteristics and advantages.
文摘Plant maintenance has been a discipline that has gradually evolved with the industrial revolution. For quite some time, it has been a "necessary evil" in production, manufacturing, and process settings. The changing business needs and industrial conditions have had various impacts on the maintenance process, particularly over the last few years. While some industries have inherent difficulties seeing what maintenance is all about, others have begun to add more flavor to the organizational maintenance practices. This article brings an overview of developments within the offshore oil and gas production sector.
文摘Aircraft on ground or down-time for its maintenance is a clear loss in revenue for an airline operation. With never ending competition and growing operating costs of aircraft, airlines continuously need to explore opportunities to reduce the aircraft down-time in order to remain sustainable. Due to round the clock operation feature of scheduled airlines, aircraft maintenance operations are generally carried out using traditional management methodologies instead of considering it as a project. Though aircraft heavy maintenance checks consist of several major tasks that can last from few weeks to a year, the maintenance organisations do not adopt modern project management methodologies. Therefore, this paper models a heavy maintenance check of an Airbus aircraft as a typical project and adopts contemporary project management methodology to explore the possibility of reducing the downtime. To this end, a case study has been done at an aircraft maintenance company to analyse the potential of this project management method in aircraft maintenance industry.
基金supported by Major International(Regional)Joint Research Project of the National Natural Science Foundation of China(61320106011)National High Technology Research and Development Program of China(863 Program)(2014AA052802)National Natural Science Foundation of China(61573224)
基金supported by the National Natural Science Foundation of China under Grant No.51007047
文摘An operation strategy of the electric vehicle (EV) battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and the possible mutual actions between battery charging and swapping. Three energy management strategies can be used in the station: charging period shifting, energy exchange between EVs, and energy supporting from surplus swapping batteries. Then an optimization model which minimizes the total energy management costs of the station is built. The Monte Carlo simulation is applied to analyze the characteristics of the EV battery charging load, and a heuristic algorithm is used to solve the strategy providing the relevant information of EVs and the battery charging and swapping station. The operation strategy can efficiently reduce battery charging during the high electricity price periods and make more reasonable use of the resources. Simulations prove the feasibility and rationality of the strategy.
文摘Currently,the investment of oil and gas industry is still facing an unfavorable environment,in which,instable factors,such as financial crisis,terrorist,religious conflicts and rigorous environmental regulations,keep mucking up the business all around the world.Meanwhile,China’s rapid energy consumption growth boosted by a booming economy has put the country to rely heavily on exported oil.It is therefore extremely urgent to expand and diversify petroleum supply channel in consideration of the country’s energy security.As the world’s economy has been slowly recovering from the slump and
文摘Generically, SCM may be said to include all activities carried out to ensure proper functioning of the supply chain. The activities included in proper management of a supply chain broadly include logistics activities, planning and control of the flow of information and materials in a firm, management of relationships with other organizations and government intervention, However, crude oil theft and pipeline vandalism are established products supply chain disruptors in Nigeria which are rendering the task of running an efficient petroleum supply chain onerous. This paper aims to establish the importance of effective supply chain strategies for companies in the oil and gas industry with special focus on the Nigerian oil and gas sector and the strategies by which the state oil and gas corporation in this sector may mitigate disruptions to its supply chain. This study investigates the enhancement of supply chain strategies towards meeting the challenge of crude oil theft and pipeline vandalism, using the Nigerian National Corporation (NNPC) as a case study. Based on this study, data were collected from two sources: A summary of incident reports obtained from NNPC and an interview with personnel in the PPMC Department. Incident report refers to a report produced when accidents such as equipment failure, injury, loss of life, or fire occur at the work site. Content analysis is utilized to evaluate data obtained from interview responses, CBN financial stability reports, NDIC annual reports, circulars, banking supervision reports and implementation guidelines. The study found out that NNPC should endeavor to sustain its value chain and ward of pipeline vandals and crude oil thieves by engaging in community partnership, detailing security outfits to ensure its pipelines’ right of way and bridging. Concluded that the oil supply chain of the Nigerian National Petroleum Corporation has been plagued by disruptions in the form of crude oil theft and pipeline vandalism which has had debilitating effects on its value.
文摘This paper is aiming to connect previous research in global competitiveness analysis, taking the impact of the global financial crisis into account, to evaluate how manufacturing companies are able to manage crisis by adjusting their manufacturing strategy and transformational leadership together with technology level to improve their global operational competitiveness performances. Based on the previous research, we developed a theoretical approach of modeling the core factors which influence the operational competitiveness performance (i.e., manufacturing strategy and transformational leadership with technology level), into conceptual analytical models to evaluate overall competitiveness. The empirical studies are focused on manufacturing companies in China, Finland, Slovakia, Iceland, and Spain. The case companies are evaluated with the proposed analytical models and their performances are compared in global context to conclude the experience of crisis management.
文摘In the current socialist market economy,if an enterprise wants to grow and develop,it must do all kinds of management for its enterprise,and the most important thing for strengthening management of enterprises is to strengthen their own operation and management abilities.Whether it is financial management,management of personnel efficiency,or management of talents,it is necessary to protect from the infrastructure,so as to fundamentally improve the economic benefits of the enterprise,and vice versa if社is not properly managed,it will affect the development of the enterprise.Therefore,improving the operation and management abilities of enterprises at present is an important factor to promote the economic development of enterprises.This paper analyzes the management problems of enterprises and the definition of enterprise operation and management abilities,and analyzes how enterprises can reform and innovate,thus strengthening the operation and management abilities and economic benefits of enterprises.
文摘Today, in the modern era, and under the pressure of rapid development around the kingdom regions, electric utilities are confronted with a myriad of challenges that include aging infrastructure, enhanced expectation of reliability, reduced cost, and coping effectively with uncertainties and changing regulation requirements. Indeed, for distribution systems, HV/MV substations represent a complex and critical physical asset that requires a careful evaluation of their maintenance practices aiming at more cost-effective tasks. The first concern of the electric power distribution company in Morocco is the optimization of the distribution network maintenance scheduling, to minimize system operating costs and ensure that the system is running most economically. There is significant pressure on power providers for greater system reliability and improvement of customer satisfaction, while similar emphasis is placed on cost reduction. These cost reductions focus on reducing operating and maintenance expenses, and minimizing investments in new plants and equipment. However, the present of the electricity distribution, influenced by a number of technical restrictions and strict regulatory requirements to meet, leads distribution utilities to search new ways of optimizing the maintenance management, make an effort to maximize profit by reducing their electricity supply and operation costs while maintaining their reliability, developing more effective activities, with lower costs. Furthermore, maximal HV/MV substation asset value and minimal maintenance cost are typical economic objectives of the electric utilities. The optimization of maintenance is one possible technique to reduce maintenance costs while improving reliability and utilities need to implement new strategies for more effective maintenance techniques and Asset Management (AM) methods programs to manage inspections and maintenance activities in order to control HV/MV substation equipment conditions. However, development of strategies to make sound decisions in order to effectively improve equipment and system reliability while meeting constraints such as a maintenance budget is a challenge. Finally, this paper describes the application of a new approach based Reliability Centered Maintenance (RCM) methodology to optimize maintenance resources and to the development of maintenance plan for HV/MV distribution substations. For this purpose, a case study was performed on the equipment of power distribution systems for the benefit of a holding company (ONEE Electricity Distribution) in Morocco. The present study was conducted in Oujda Exploitation Maintenance Service (OEXMS), in charge of operation and maintenance of distribution networks.
文摘This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable energy and reduce the cost of investment and operation. Next, the problems in the optimal planning for a stand-alone microgrid system are summarized, including the unique operational control targets, the flexible combination approaches and the operation strategies of distributed generation energy supply system, and the special requirements of the reliability of power supply quality factor from the different users. And then, centering on the operational control and the advanced energy management strategy, the optimal mathematical models and the solving methods, the reliability assessment approaches and the improvement measures of a stand-alone microgrid system, an overview of the general situation of the recent research at home and abroad and the limitations of the study are summarized. Finally, several problems, existing in the optimal planning of stand-alone microgrid system, to be urgently solved, are put forward.
文摘Kabul New City is a new capital development and a modern city development of Afghanistan covering total area of 740 km<sup>2</sup>. In 2009 Afghan cabinet approved developing New Capital to fulfill the requirement of growing population. For sustainable development, it has been planned to have a green belt and central park about 1298 hectares within the city. It is having positive impact on human health along with the economic, social and environmental benefits. Hence, for sustaining the urban parks, their proper maintenance is a foremost problem. The solid waste management is duly considered in planning stage of development, otherwise, it would encounter major challenges during operation and maintenance of Park. The projected waste generation in KNC park area is required to be assessed, therefore, surveys of Bagh-e-Babur in existing Kabul are carried out for the visitors’ projection and solid waste generation. The highest visitors and waste were estimated in declining order of summer, spring, fall, and winter. Kabul New City Central Park results speculate that the total visitors’ projection is going to be 6,745,313 per year generating about 337 metric tons wastes/year (0.05 kg/visitor/day). 10 Vehicles of capacity 8 m<sup>3</sup> are required to collect waste from central park towards the Transfer Station while 4 vehicles of 23 m<sup>3</sup> are required for collection of waste from TS to Landfill. Moreover, 700 containers of 240 liters are required in the park. Furthermore, different sites were indicated in map for composting area where after the development it would be considered.
基金the financial support for this research from the National Natural Science Foundation of China(52176063)the International Science and Technology projects of Huangpu District of Guangzhou City(2020GH08)the Guangzhou Science and Technology Plan Project(201907010036)。
文摘The effective cathode flow field design can realize the internal water balance and higher current density output of proton exchange membrane fuel cells(PEMFC).Therefore,a segmented water management flow field is proposed in this study,i.e.a half separated-half coupled cathode(HSHC)flow field which has two inlets but just one outlet.A 3D numerical PEMFC model is applied to study the effect of the HSHC flow field on PEMFC performance and its operating strategy in terms of operating conditions.The study results are shown as follows:Compared with the two conventional cathode flow fields,the HSHC flow field improves the water balance along the channel and increases the current density by 17.1%at a cathode stoichiometry of 3.25.It is because the HSHC flow field can overcome the water loss at channels upstream and the water accumulation at channels downstream.The draw water phenomenon(DWP)in the HSHC flow field is observed,which is mainly affected by the water vapor pressure of channel.Based on the DWP,cooling channel inlet flow rates can be used to adjust water balance,but severe water loss should be avoided.In addition,the inlet temperature control in HSHC flow field should be that cell temperature>cathode channel inlet temperature>cooling channel inlet temperature>ambient temperatures for better water balance.
文摘This paper explores the operational strategies of cross-border micro, small, and medium enterprises (MSMEs). Against the backdrop of globalization and digitalization, cross-border trade has become one of the important pathways for many MSMEs to achieve growth and competitive advantage. Firstly, the paper outlines the concept and characteristics of cross-border MSMEs, as well as the analysis of their operational environment in the context of globalization, including political, economic, social, technological, environmental, and legal factors. Secondly, the paper proposes operational strategies for cross-border MSMEs, including international market selection and positioning, cross-border marketing strategies, supply chain management, cross-border financial management, and cross-border risk management. Finally, the paper summarizes the importance of effectively implementing these strategies for cross-border MSMEs to seize international market opportunities, reduce operational risks, and enhance competitiveness and profitability.
文摘The topic investigated competition in marketing as a survival yardstick for small and medium enterprises (SMEs) in Nigeria. The objectives addressed by this study were: (1) identifying different types and intensity of competition that SMEs are exposed to along the life-cycle portfolio in Nigeria; (2) quantifying the strength of SMEs vis-a-vis some foreign enterprises in terms of market competition; and (3) proffering solutions on how best they could match competitively these foreign enterprises. Relevant models and theories were employed in literature to evolve detailed analysis of issues relating to the variables used in terms of competition in marketing and survival of juice-producing SMEs. Two hypotheses were investigated through the survey of 20 prominent Ikeja based SMEs using Cluster sampling, 5-points Likert summated rating scale was adopted, while Yard's formula with 95% confidence level and 5% error tolerance was used. Alternative form validity of the instrument was measured at 0.63 while its reliability was measured at Cronbach's alpha of 0.70. Pearson's product-moment correlation was used in testing hypothesis 1 while standard multiple regressions were used to test hypothesis 2. Findings revealed that there was strong relationship between survival of juice-producing SMEs with forms of competition on a firm's life-cycle; while competition had positive effects on survival components for the enterprises. It was concluded that since competition subsists in any firm's life-cycle, strategies to support operations for survival must be adopted. It was recommended that operators of SMEs have to monitor and manage competition as it affects their businesses positively and/or negatively.