In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the f...In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the former vessel via an STS （ship-to-ship） mooring system. We obtain hydrodynamic forces using the HOBEM （higher-order boundary element method）. Then, we determine their coefficients using the convolution function method in the time domain. We model the catenary mooring lines using the finite element method, and the STS mooring lines are treated as linear SPs （springs） with constraints. To optimize the STS system, we conduct parametric studies on STS mooring systems. Finally, we compare the motion and structural responses of the initial and modified configurations.展开更多
A fuzzy control scheme is presented according to the coal quantity in the main coal bunker, this method has a good dynamic response characteristic and is suited for complex nonlin-ear systems. The designation of self-...A fuzzy control scheme is presented according to the coal quantity in the main coal bunker, this method has a good dynamic response characteristic and is suited for complex nonlin-ear systems. The designation of self-adopting fuzzy controller, the working principle and functions of this system are also proposed, with the hardware and the main flow diagram of this system in-troduced in this paper.展开更多
In order to reduce waiting time in port for large LNG （liquefied natural gas） fueled ships, it is suggested that LNG STS （ship to ship） bunkering and cargo loading/unloading should be carried out simultaneously. T...In order to reduce waiting time in port for large LNG （liquefied natural gas） fueled ships, it is suggested that LNG STS （ship to ship） bunkering and cargo loading/unloading should be carried out simultaneously. This study investigated the safety zone of an LNG bunkering vessel with 10,000 cubic meters capacity transferring LNG fuel to an LNG fueled 18,000 TEU containership. Four LNG leakage scenarios were identified based on failure frequencies analysis of piping systems and severity of consequence, three-dimension CFD software FLACS was adopted to calculate flammable cloud dispersion after LNG leakage. As a result, we obtained a rectangle dangerous zone （41.3 m ~ 126 m）, outside of this dangerous zone can be def＇med as safety zone. It is concluded that safety zone of LNG STS bunkering and cargo loading/unloading SIMOPS （simultaneous operations） cannot keep the same, there are different results for different designs and operation locations. Due to high frequencies and severe consequences, two typical scenarios, the leakage of LNG hose and the natural gas releases from bunkering tank＇s safety relief valve during bunkering, cannot be ignored in similar study.展开更多
Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system’s total throughput as a obje...Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system’s total throughput as a objective, the method of determining the surge bunker’s rational size is put forward. Also, the problems of rational position of surge bunker are analysesed.展开更多
To assess the deformation of a coal bunker and propose effective preventative measures for such,a real-time monitoring system was designed.Moreover,methods were proposed for monitoring the coal-bunker inclination,sett...To assess the deformation of a coal bunker and propose effective preventative measures for such,a real-time monitoring system was designed.Moreover,methods were proposed for monitoring the coal-bunker inclination,settlement,groundwater level,temperature,and material level.By using a vector autoregression model and time-series data for the coal-bunker deformation,a long-term equilibrium relationship was derived between the coal-bunker inclination and settlement and their influencing factors.The dynamic effects of each factor on the coal-bunker inclination and settlement and how the contribution of each factor changes were revealed by using an impulse response function and variance decomposition.The results show that the coal-bunker inclination and settlement vary hysteretically.Groundwater level has constant and small negative effects on the coal-bunker inclination and settlement,and temperature has continuous and significant negative effects;however,material level has constant positive effects on the coal-bunker settlement and slightly influences the eastward inclination while significantly influencing the northward inclination of the coal bunker.Also,unbalanced loading has little influence on the coal-bunker settlement and eastward inclination but significant influence on its northward inclination.Therefore,monitoring of the coal-bunker deformation should be strengthened in summer,and sudden changes in material level and unbalanced loading should be avoided during production.Moreover,the coal-bunker inclination can be adjusted by unbalanced loading in the reverse direction.展开更多
With the long-term use of coal bunker, a certain amount of sticking objects will beformed on its wall, and coal mine clearing robot can replace man in clearing the bunker wall.Also, since it equip with an explosion-pr...With the long-term use of coal bunker, a certain amount of sticking objects will beformed on its wall, and coal mine clearing robot can replace man in clearing the bunker wall.Also, since it equip with an explosion-proof camera, the worker can determine the operationby observing the well-head monitor.Moreover, it cannot work unless it is placed in positionand supported stably, and it has three degrees of freedom: rotating, stretching, and shovelcoal.It is driven by the hydraulic and controlled by PLC.The underground coal mine clearingrobot changs the traditional clearing methods, man does not have to enter the bunker toclear it, which ensures the production safety of coal transportation.展开更多
Discussed the necessity of setting up the coal bunker in mining, introduced the development of coal bunker technology, combining the mining characteristic of the high yield and high-efficient working face in China at ...Discussed the necessity of setting up the coal bunker in mining, introduced the development of coal bunker technology, combining the mining characteristic of the high yield and high-efficient working face in China at present, and point out that the type of horizontal coal bunker, is a kind of security, high-efficient coal store and transportation technology of suiting the modern production need of the colliery, is the developing direc-tion of technology of store and transportation of coal bunker.展开更多
A great attention has been paid to slowing the degradation of coal nowadays. The spiral bunker is the main measure to lower the degradation. In this paper the application and research of spiral bunker are introduced. ...A great attention has been paid to slowing the degradation of coal nowadays. The spiral bunker is the main measure to lower the degradation. In this paper the application and research of spiral bunker are introduced. And two non-normal spiral chutes are discussed. One is in the tangential direction of the inner wall of the bunker, another is in the direction of the diameter of the bunker. Mathematical models of the non-normal spiral chutes are set up to optimize the geometrical parameters of the spiral curved surface, which would ensure that coal travels smoothly to the bottom of the bunker. The results would be useful for designing and retrofitting the spiral bunker.展开更多
Within the scope of certain social and religious movements, mesmerism had a considerable impact on the Americanway of life during the last decades of 19th century. A famous example is the Christian Science of Mary Bak...Within the scope of certain social and religious movements, mesmerism had a considerable impact on the Americanway of life during the last decades of 19th century. A famous example is the Christian Science of Mary Baker EddyBut also less known groups adopted mesmeric ideas and practices. The paper focuses on the concept of＂Karezza＂.It combined a specific sexual practice with religious ideas of divine love, birth control, social reform, women＇semancipation and health education. It was created by Alice Bunker Stockham （1833-1912）, an obstetrician andgynecologist from Chicago. Among other authorities, the writer Leo Tolstoy and medical psychologist HavelockEllis appreciated her approach. She was a pioneer of the sexual and marriage reform promoting practical advice foreveryday life. As a doctor, she stressed especially the disastrous consequences of a brutal sexual life destroyingbody and mind （not only of the women）. As an antidote, she propagated the ＂Karezza love＂ avoiding ejaculation ada punctual orgasm （climax） during intercourse. The leading idea was the imagery of a mesmeric ＂fluidum＂ unitingindividuals spiritually. Bunker＇s publications were translated into German. They corresponded to the Lebensreformmovement, but never became popular. Also the early sexology about 1900 ignored Bunker＇s concept as well as thesexual medicine later on. It is worthwhile to reconsider it within the context of the history of medicine, culture, andanthropology.展开更多
Liquified natural gas(LNG)bunkering simultaneous operations(SIMOPs)refers to the operations(such as cargo operations,port activities and ship maintenance)occurring around LNG bunkering.SIMOPs pose new risks to LNG bun...Liquified natural gas(LNG)bunkering simultaneous operations(SIMOPs)refers to the operations(such as cargo operations,port activities and ship maintenance)occurring around LNG bunkering.SIMOPs pose new risks to LNG bunkering,because the operations are dynamically interlocked in which the occurrence probabilities of potential consequences change at different times due to commencement or completion of specific SIMOP events.However,traditional static risk assessment approaches are not able to take the dynamic nature of these new risks into account.This article proposes a dynamic quantitative risk as-sessment(DQRA)methodology based on the Bayesian network(BN)to develop better understanding of dynamic risks of LNG bunkering SIMOPs.The methodology is demonstrated and evaluated through a truck-to-ship LNG bunkering case study.The results and discussion of the case study validate the utility of the proposed methodology and demonstrate that BNs are efficient in performing the probability calcu-lations and are flexible in conducting causal diagnosis.The main innovation of this work is realizing the quantification of risks at different times,which reflects the most essential time-changing characteristics of risks associated with LNG bunkering SIMOPs.展开更多
A cyclone dust collector is applied in many industries. Especially the axial flow cyclone is the mostsimple construction and it keeps high reliability for maintenance. On the other hand, the collectionefficiency of th...A cyclone dust collector is applied in many industries. Especially the axial flow cyclone is the mostsimple construction and it keeps high reliability for maintenance. On the other hand, the collectionefficiency of the cyclone depends not only on the inlet gas velocity but also on the feed particle concentration. The collection efficiency increases with increasing feed particle concentration. However untilnow the problem of how to estimate the collection efficiency depended on the feed particle concentrationis remained except the investigation by Muschelknautz & Brunner~[6]. Therefore in this paper one ofthe estimate method for the collection efficiency of the axial flow cyclones is proposed. The applicationto the geometrically similar type of cyclone of the body diameters D_1=30, 50, 69 and 99 mm showedin good agreement with the experimental results of the collection efficiencies which were described indetail in the paper by Ogawa & Sugiyama~[8].展开更多
he bunker industry has faced negative perception to their trust and credibility in recent times.This is further compounded by the need for the industry to answer new challenges to meet the requirement of the Internati...he bunker industry has faced negative perception to their trust and credibility in recent times.This is further compounded by the need for the industry to answer new challenges to meet the requirement of the International Maritime Organization 2020.The aim of this work is to illustrate how blockchain technology may be adopted for aiding in bunker dispute resolution.To demonstrate how blockchain may aid in disputes within the bunker industry,this paper first examines the existing bunker supply process,which involves the formation of contracts under English law,the Bunker Delivery Notes,the different types of disputes that may arise during a bunker transaction and the methods of dispute resolution utilised by the industry.Furthermore,the current literature in relation to blockchain technology and blockchain smart contracts is examined.Finally,interviews and surveys within the industry have been conducted to identify the benefits and challenges in adopting blockchain technology.The research found that blockchains may benefit the bunker supply chain offering the effective resolution of bunker quality disputes.Furthermore,blockchains may also serve as a verification tool for electronic bunker delivery notes,which may aid quality and quantity bunker disputes as well as compliance with the new International Maritime Organisation 2020 requirements.As a result,despite the research having shown blockchain to be situationally dependent and having an element of legal uncertainty,blockchain does offer a solution to aid in bunker disputes and for improving the trust and credibility within the bunker industry.展开更多
Due to the long operation cycle of maritime transportation and frequent fluctuations of the bunker fuel price, the refueling expenditure of a chartered ship at different time or ports of call make significant differen...Due to the long operation cycle of maritime transportation and frequent fluctuations of the bunker fuel price, the refueling expenditure of a chartered ship at different time or ports of call make significant difference. From the perspective of shipping company, an optimal set of refueling schemes for a ship fleet operating on different voyage charter routes is an important decision. To address this issue, this paper presents an approach to optimize the refueling scheme and the ship deployment simultaneously with considering the trend of fuel price fluctuations. Firstly, an ARMA model is applied to forecast a time serials of the fuel prices. Then a mixed-integer nonlinear programming model is proposed to maximize total operating profit of the shipping company. Finally, a case study on a charter company with three bulk carriers and three voyage charter routes is conducted. The results show that the optimal solution saves the cost of 437,900 USD compared with the traditional refueling scheme, and verify the rationality and validity of the model.展开更多
文摘In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the former vessel via an STS （ship-to-ship） mooring system. We obtain hydrodynamic forces using the HOBEM （higher-order boundary element method）. Then, we determine their coefficients using the convolution function method in the time domain. We model the catenary mooring lines using the finite element method, and the STS mooring lines are treated as linear SPs （springs） with constraints. To optimize the STS system, we conduct parametric studies on STS mooring systems. Finally, we compare the motion and structural responses of the initial and modified configurations.
文摘A fuzzy control scheme is presented according to the coal quantity in the main coal bunker, this method has a good dynamic response characteristic and is suited for complex nonlin-ear systems. The designation of self-adopting fuzzy controller, the working principle and functions of this system are also proposed, with the hardware and the main flow diagram of this system in-troduced in this paper.
文摘In order to reduce waiting time in port for large LNG （liquefied natural gas） fueled ships, it is suggested that LNG STS （ship to ship） bunkering and cargo loading/unloading should be carried out simultaneously. This study investigated the safety zone of an LNG bunkering vessel with 10,000 cubic meters capacity transferring LNG fuel to an LNG fueled 18,000 TEU containership. Four LNG leakage scenarios were identified based on failure frequencies analysis of piping systems and severity of consequence, three-dimension CFD software FLACS was adopted to calculate flammable cloud dispersion after LNG leakage. As a result, we obtained a rectangle dangerous zone （41.3 m ~ 126 m）, outside of this dangerous zone can be def＇med as safety zone. It is concluded that safety zone of LNG STS bunkering and cargo loading/unloading SIMOPS （simultaneous operations） cannot keep the same, there are different results for different designs and operation locations. Due to high frequencies and severe consequences, two typical scenarios, the leakage of LNG hose and the natural gas releases from bunkering tank＇s safety relief valve during bunkering, cannot be ignored in similar study.
文摘Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system’s total throughput as a objective, the method of determining the surge bunker’s rational size is put forward. Also, the problems of rational position of surge bunker are analysesed.
基金Financial support for this work was provided by the National Natural Science Foundation of China(No.52004202)the Scientific Research Program Funded by Shaanxi Provincial Education Department(No.20JK0236)+2 种基金the Humanities and Social Science Fund of the Ministry of Education of China(No.20YJC630190)the China Postdoctoral Science Foundation(No.2019M663781)the Innovation Capability Support Program of Shaanxi(No.2021KRM009).
文摘To assess the deformation of a coal bunker and propose effective preventative measures for such,a real-time monitoring system was designed.Moreover,methods were proposed for monitoring the coal-bunker inclination,settlement,groundwater level,temperature,and material level.By using a vector autoregression model and time-series data for the coal-bunker deformation,a long-term equilibrium relationship was derived between the coal-bunker inclination and settlement and their influencing factors.The dynamic effects of each factor on the coal-bunker inclination and settlement and how the contribution of each factor changes were revealed by using an impulse response function and variance decomposition.The results show that the coal-bunker inclination and settlement vary hysteretically.Groundwater level has constant and small negative effects on the coal-bunker inclination and settlement,and temperature has continuous and significant negative effects;however,material level has constant positive effects on the coal-bunker settlement and slightly influences the eastward inclination while significantly influencing the northward inclination of the coal bunker.Also,unbalanced loading has little influence on the coal-bunker settlement and eastward inclination but significant influence on its northward inclination.Therefore,monitoring of the coal-bunker deformation should be strengthened in summer,and sudden changes in material level and unbalanced loading should be avoided during production.Moreover,the coal-bunker inclination can be adjusted by unbalanced loading in the reverse direction.
文摘With the long-term use of coal bunker, a certain amount of sticking objects will beformed on its wall, and coal mine clearing robot can replace man in clearing the bunker wall.Also, since it equip with an explosion-proof camera, the worker can determine the operationby observing the well-head monitor.Moreover, it cannot work unless it is placed in positionand supported stably, and it has three degrees of freedom: rotating, stretching, and shovelcoal.It is driven by the hydraulic and controlled by PLC.The underground coal mine clearingrobot changs the traditional clearing methods, man does not have to enter the bunker toclear it, which ensures the production safety of coal transportation.
文摘Discussed the necessity of setting up the coal bunker in mining, introduced the development of coal bunker technology, combining the mining characteristic of the high yield and high-efficient working face in China at present, and point out that the type of horizontal coal bunker, is a kind of security, high-efficient coal store and transportation technology of suiting the modern production need of the colliery, is the developing direc-tion of technology of store and transportation of coal bunker.
文摘A great attention has been paid to slowing the degradation of coal nowadays. The spiral bunker is the main measure to lower the degradation. In this paper the application and research of spiral bunker are introduced. And two non-normal spiral chutes are discussed. One is in the tangential direction of the inner wall of the bunker, another is in the direction of the diameter of the bunker. Mathematical models of the non-normal spiral chutes are set up to optimize the geometrical parameters of the spiral curved surface, which would ensure that coal travels smoothly to the bottom of the bunker. The results would be useful for designing and retrofitting the spiral bunker.
文摘Within the scope of certain social and religious movements, mesmerism had a considerable impact on the Americanway of life during the last decades of 19th century. A famous example is the Christian Science of Mary Baker EddyBut also less known groups adopted mesmeric ideas and practices. The paper focuses on the concept of＂Karezza＂.It combined a specific sexual practice with religious ideas of divine love, birth control, social reform, women＇semancipation and health education. It was created by Alice Bunker Stockham （1833-1912）, an obstetrician andgynecologist from Chicago. Among other authorities, the writer Leo Tolstoy and medical psychologist HavelockEllis appreciated her approach. She was a pioneer of the sexual and marriage reform promoting practical advice foreveryday life. As a doctor, she stressed especially the disastrous consequences of a brutal sexual life destroyingbody and mind （not only of the women）. As an antidote, she propagated the ＂Karezza love＂ avoiding ejaculation ada punctual orgasm （climax） during intercourse. The leading idea was the imagery of a mesmeric ＂fluidum＂ unitingindividuals spiritually. Bunker＇s publications were translated into German. They corresponded to the Lebensreformmovement, but never became popular. Also the early sexology about 1900 ignored Bunker＇s concept as well as thesexual medicine later on. It is worthwhile to reconsider it within the context of the history of medicine, culture, andanthropology.
文摘Liquified natural gas(LNG)bunkering simultaneous operations(SIMOPs)refers to the operations(such as cargo operations,port activities and ship maintenance)occurring around LNG bunkering.SIMOPs pose new risks to LNG bunkering,because the operations are dynamically interlocked in which the occurrence probabilities of potential consequences change at different times due to commencement or completion of specific SIMOP events.However,traditional static risk assessment approaches are not able to take the dynamic nature of these new risks into account.This article proposes a dynamic quantitative risk as-sessment(DQRA)methodology based on the Bayesian network(BN)to develop better understanding of dynamic risks of LNG bunkering SIMOPs.The methodology is demonstrated and evaluated through a truck-to-ship LNG bunkering case study.The results and discussion of the case study validate the utility of the proposed methodology and demonstrate that BNs are efficient in performing the probability calcu-lations and are flexible in conducting causal diagnosis.The main innovation of this work is realizing the quantification of risks at different times,which reflects the most essential time-changing characteristics of risks associated with LNG bunkering SIMOPs.
文摘A cyclone dust collector is applied in many industries. Especially the axial flow cyclone is the mostsimple construction and it keeps high reliability for maintenance. On the other hand, the collectionefficiency of the cyclone depends not only on the inlet gas velocity but also on the feed particle concentration. The collection efficiency increases with increasing feed particle concentration. However untilnow the problem of how to estimate the collection efficiency depended on the feed particle concentrationis remained except the investigation by Muschelknautz & Brunner~[6]. Therefore in this paper one ofthe estimate method for the collection efficiency of the axial flow cyclones is proposed. The applicationto the geometrically similar type of cyclone of the body diameters D_1=30, 50, 69 and 99 mm showedin good agreement with the experimental results of the collection efficiencies which were described indetail in the paper by Ogawa & Sugiyama~[8].
文摘he bunker industry has faced negative perception to their trust and credibility in recent times.This is further compounded by the need for the industry to answer new challenges to meet the requirement of the International Maritime Organization 2020.The aim of this work is to illustrate how blockchain technology may be adopted for aiding in bunker dispute resolution.To demonstrate how blockchain may aid in disputes within the bunker industry,this paper first examines the existing bunker supply process,which involves the formation of contracts under English law,the Bunker Delivery Notes,the different types of disputes that may arise during a bunker transaction and the methods of dispute resolution utilised by the industry.Furthermore,the current literature in relation to blockchain technology and blockchain smart contracts is examined.Finally,interviews and surveys within the industry have been conducted to identify the benefits and challenges in adopting blockchain technology.The research found that blockchains may benefit the bunker supply chain offering the effective resolution of bunker quality disputes.Furthermore,blockchains may also serve as a verification tool for electronic bunker delivery notes,which may aid quality and quantity bunker disputes as well as compliance with the new International Maritime Organisation 2020 requirements.As a result,despite the research having shown blockchain to be situationally dependent and having an element of legal uncertainty,blockchain does offer a solution to aid in bunker disputes and for improving the trust and credibility within the bunker industry.
基金Supported by the National Natural Science Foundation of China(71303026)China Postdoctoral Science Foundation(2015M580128)+2 种基金Liaoning Natural Science Foundation(2015020074)Higher Education Development Fund(for Collaborative Innovation Center)of Liaoning(20110116102)Teaching Reform Fund of Dalian Maritime University(2014Y18)
文摘Due to the long operation cycle of maritime transportation and frequent fluctuations of the bunker fuel price, the refueling expenditure of a chartered ship at different time or ports of call make significant difference. From the perspective of shipping company, an optimal set of refueling schemes for a ship fleet operating on different voyage charter routes is an important decision. To address this issue, this paper presents an approach to optimize the refueling scheme and the ship deployment simultaneously with considering the trend of fuel price fluctuations. Firstly, an ARMA model is applied to forecast a time serials of the fuel prices. Then a mixed-integer nonlinear programming model is proposed to maximize total operating profit of the shipping company. Finally, a case study on a charter company with three bulk carriers and three voyage charter routes is conducted. The results show that the optimal solution saves the cost of 437,900 USD compared with the traditional refueling scheme, and verify the rationality and validity of the model.
