The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit (FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced lo...The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit (FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced loading, the refined finite element model for hot spot stress calculation, the combination of stress components, and fatigue damage assessment based on S-N curve.展开更多
In view of the existing situation of gas field development, one kind of method to evaluate the production performance of gas production units (GPUs) was presented in this paper. Among the commonly used indicators of g...In view of the existing situation of gas field development, one kind of method to evaluate the production performance of gas production units (GPUs) was presented in this paper. Among the commonly used indicators of gas field development, we select 11 indicators from the three aspects of production task, gas reservoir management, and production technology. According to the principle of analytic network process (ANP), this paper introduced one kind of new method to get the weights of indicators. By means of the method of TOPSIS, it is easy to obtain the rankings for all the GPUs through calculating the weighted Euclidean distance between each GPU and the positive or negative ideal point. This evaluation method could constantly improve the management level of gas production units and deepen the delicacy management of gas field development.展开更多
After many years of exploitation,onshore oil and gas resources are about to enter a recession period.Oil and gas will mainly come from oceans in the future.Generally speaking,the exploration and production(E&P)cos...After many years of exploitation,onshore oil and gas resources are about to enter a recession period.Oil and gas will mainly come from oceans in the future.Generally speaking,the exploration and production(E&P)cost of oil from offshore is much higher than that of oil from onshore,so it is more sensitive to oil price.However,in recent years,oil price has been hovering at a low level for a long time,almost close to or even lower than the E&P cost of oil,which directly affects the development of oilfields.Besides the influence of oil price,some oilfields present the characteristics of marginal reserve scale,short peak production period and output rapidly declining.There leads to short economic life period and makes the economic benefit close to or lower than oilfield’s hurdle rate,which increases the difficulty of offshore oilfield development.As an important part of oilfield development,Floating Production Storage and Offloading unit,its investment mode and rent mode directly affect overall oilfield’s rate of return and the economic life.This paper chooses lease mode as the research object based on the analysis of investment mode,and further puts forward rent mode related with oil price through the analysis of traditional rent mode,and illustrates the advantages and disadvantages of various rent modes and their applicability so that the lessor chooses the right mode to achieve Win-Win with Oil Company and promotes the development of oilfields under low oil price.展开更多
The aims of this study were to investigate the food safety knowledge and practices of food handlers and to assess the sanitary conditions of attieke production units in the South of C?te d’Ivoire. A cross-sectional s...The aims of this study were to investigate the food safety knowledge and practices of food handlers and to assess the sanitary conditions of attieke production units in the South of C?te d’Ivoire. A cross-sectional study was conducted during 4 months in 2012 in 7 localities and data were collected using questionnaire and observation checklist and microbiological analysis of hands. A total of 775 attieke production units were involved in this survey. Seventy-one percent (71%) were located on public domains and only 70 production units (9%) used septic tank as a mean of final deposal for liquid waste. Hygiene conditions and practices of food handlers in attieke production units were inadequate. The presence of specific microorganisms such as Staphylococcus aureus, Klebsiella pneumoniae, Enterobacter agglomerans, Citrobacter youngae, Klebsiella oxytoca and Citrobacter freundi was indicative of a degree of ignorance on the part of food handlers towards proper hygienic practices.展开更多
Most measurements for beef improvement in South Africa are per individual (weaning weight, calving interval, growth rate, etc.). A measurement that expresses performance per constant unit, e.g. kilogram calf weaned pe...Most measurements for beef improvement in South Africa are per individual (weaning weight, calving interval, growth rate, etc.). A measurement that expresses performance per constant unit, e.g. kilogram calf weaned per Large Stock Unit (LSU) can eventually be translated to kilogram calf produced per kg CO2 equivalent. A LSU is defined as a bovine requiring 75 MJ Metabolisable Energy (ME) per day. If more kilogram weaner calf can be produced per LSU (KgC/LSU), the carbon footprint of beef can be reduced. This study used breed average values to investigate the KgC/LSU for the 30 beef and dual purpose breeds in South Africa. The breeds were categorized in the following breed types: Sanga (indigenous to South Africa) Sanga derived, Zebu, Zebu derived, British and European. No relationship was found between cow weights and KgC/LSU, indicating that it is independent of cow weight between breeds. However, when the data is summarized into breed types, the Sanga and European breed types produce the least KgC/ LSU and Sanga derived breed types the most. This high value of the Sanga derived breeds is probably due to retained heterosis. Composite breeds are mostly intermediate to parental breeds for individual traits but superior for composite traits and KgC/LSU is a composite trait. These calculations were only done on breed averages. A genetic analysis on a breed level to estimate genetic parameters for this trait, and its genetic correlations with other traits now needs to be done before a decision can be taken whether selection for KgC/LSU will be feasible. The ultimate aim with a trait like this is to reduce the carbon footprint of weaner calf production since more kilogram calf will be produced per LSU (constant feed unit).展开更多
Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook,this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting f...Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook,this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting factors.The results show that:1) During 1980 to 2007,total grain production increased from 3.20 × 108 t to 5.02 × 108 t in China,with annual increasing rate of 1.68%.From the regional disparities,most of the regions present increasing trend of total grain production except for several regions with higher level of economic development;2) Grain sown area decreased from 1.17 × 108 ha in 1980 to 1.06 × 108 ha in 2007,which has negative effect on total grain production;3) The increase of grain yield per unit area caused by land use intensity changes contributed to the increase of total grain yield greatly.However,as the land use intensity showed that farmers pay more attention to labor-saving input but not yield-increasing input,the less enthusiasm of farmers in grain production may become an important constraint on fu-ture grain production increase in China;4) Based on the results,this paper proposed different land management poli-cies in different regions,for example,the government should protect cultivated land,promote large scale production.As to the less developed regions,the government should pay more attention to agricultural subsidies to promote farm-ers' enthusiasm in grain production.展开更多
The internal turret mooring system for oil production storage vessels is a developing type ofoffshore floating production system suitable for deep water and harsh environmental application. In this paper, some achieve...The internal turret mooring system for oil production storage vessels is a developing type ofoffshore floating production system suitable for deep water and harsh environmental application. In this paper, some achievements in our research work are presented. The description includes: dynamic analysis of mooring system, research on performance of turret assembly, influence of vessel dimensions and hull forms on mooring performance, model tests under combined action of environmental forces in basin, and hull structural strength analysis.展开更多
It is expected that by 2025 China will add a total ethylene production capacity of 12 Mt/a,and in the next decade the total ethylene capacity will reach 35―40 Mt/a.The grassroots 11 new steam cracking units slated fo...It is expected that by 2025 China will add a total ethylene production capacity of 12 Mt/a,and in the next decade the total ethylene capacity will reach 35―40 Mt/a.The grassroots 11 new steam cracking units slated for production by the end of 2022 are listed in the following Table.展开更多
A novel rule-based model for multi-stage multi-product scheduling problem(MMSP)in batch plants with parallel units is proposed.The scheduling problem is decomposed into two sub-problems of order assignment and order s...A novel rule-based model for multi-stage multi-product scheduling problem(MMSP)in batch plants with parallel units is proposed.The scheduling problem is decomposed into two sub-problems of order assignment and order sequencing.Firstly,hierarchical scheduling strategy is presented for solving the former sub-problem,where the multi-stage multi-product batch process is divided into multiple sequentially connected single process stages,and then the production of orders are arranged in each single stage by using forward order assignment strategy and backward order assignment strategy respectively according to the feature of scheduling objective.Line-up competition algorithm(LCA)is presented to find out optimal order sequence and order assignment rule,which can minimize total flow time or maximize total weighted process time.Computational results show that the proposed approach can obtain better solutions than those of the literature for all scheduling problems with more than 10 orders.Moreover,with the problem size increasing,the solutions obtained by the proposed approach are improved remarkably.The proposed approach has the potential to solve large size MMSP.展开更多
The article describes funding models in Germany,France,UK and in Poland.The second part of the article concentrates on entrepreneurial implications and the context.At the end of the article of financing path is descri...The article describes funding models in Germany,France,UK and in Poland.The second part of the article concentrates on entrepreneurial implications and the context.At the end of the article of financing path is described including public funding opportunities in Europe from a game developers’perspective.展开更多
Ruby—the country’s first seriescosmetics The Ruby Beauty Parlor andCosmetics School is the first of its kind inChina. The skin-care and make-upmethods it has applied are still popular.Among the gifts presented to qu...Ruby—the country’s first seriescosmetics The Ruby Beauty Parlor andCosmetics School is the first of its kind inChina. The skin-care and make-upmethods it has applied are still popular.Among the gifts presented to queenElizabeth Ⅱ of Britain, British PrimeMinister Mrs. Thatcher and RussianPresident Gorbachev by the Chinesegovernment, there was Ruby. According to market surveys andthe conclusions of beauty culture, workingwomen in modern society with their fastrhythm of life and exquisite tastes arefastidious in selecting cosmetics. To meettheir special needs, Ruby’s white展开更多
Capella油田是哥伦比亚南部重要的稠油油田,目前处于开发生产阶段,为了油田的稳产增产,需频繁对油井进行干预。Flush by Unit具有操作简单、移动高效、作业时间缩短、安全事故少等优点,作为试点引入了Flush by Unit为该油田的浅井提供...Capella油田是哥伦比亚南部重要的稠油油田,目前处于开发生产阶段,为了油田的稳产增产,需频繁对油井进行干预。Flush by Unit具有操作简单、移动高效、作业时间缩短、安全事故少等优点,作为试点引入了Flush by Unit为该油田的浅井提供修井服务,以降低桶油成本。本文介绍了Flush by Unit的结构组成、使用范围、现场使用效果,与传统修井机相比,可以大幅降低作业时间和成本,为后续规模使用Flush by Unit进行常规修井提供了依据,也为油田的增产稳产带来了机遇。展开更多
The integrated circuit (IC) manufacturing process is capital intensive and complex. The production process of unit product (or die, as it is commonly referred to) takes several weeks. Semiconductor factories (fabs) co...The integrated circuit (IC) manufacturing process is capital intensive and complex. The production process of unit product (or die, as it is commonly referred to) takes several weeks. Semiconductor factories (fabs) continuously attempt to improve their productivity, as measured in output and cycle time (or mean flow time). The conflicting objective of producing maximum units at minimal production cycle time and at the highest quality, as measured by die yield, is discussed in this paper. The inter-related effects are characterized, and a model is proposed to address this multi-objective function. We then show that, with this model, die cost can be optimized for any given operating conditions of a fab. A numerical example is provided to illustrate the practicality of the model and the proposed optimization method.展开更多
We present a systematic summary of the geological characteristics,exploration and development history and current state of shale oil and gas in the United States.The hydrocarbon-rich shales in the major shale basins o...We present a systematic summary of the geological characteristics,exploration and development history and current state of shale oil and gas in the United States.The hydrocarbon-rich shales in the major shale basins of the United States are mainly developed in six geological periods:Middle Ordovician,Middle-Late Devonian,Early Carboniferous(Middle-Late Mississippi),Early Permian,Late Jurassic,and Late Cretaceous(Cenomanian-Turonian).Depositional environments for these shales include intra-cratonic basins,foreland basins,and passive continental margins.Paleozoic hydrocarbon-rich shales are mainly developed in six basins,including the Appalachian Basin(Utica and Marcellus shales),Anadarko Basin(Woodford Shale),Williston Basin(Bakken Shale),Arkoma Basin(Fayetteville Shale),Fort Worth Basin(Barnett Shale),and the Wolfcamp and Leonardian Spraberry/Bone Springs shale plays of the Permian Basin.The Mesozoic hydrocarbon-rich shales are mainly developed on the margins of the Gulf of Mexico Basin(Haynesville and Eagle Ford)or in various Rocky Mountain basins(Niobrara Formation,mainly in the Denver and Powder River basins).The detailed analysis of shale plays reveals that the shales are different in facies and mineral components,and"shale reservoirs"are often not shale at all.The United States is abundant in shale oil and gas,with the in-place resources exceeding 0.246×10^(12)t and 290×10^(12)m^(3),respectively.Before the emergence of horizontal well hydraulic fracturing technology to kick off the"shale revolution",the United States had experienced two decades of exploration and production practices,as well as theory and technology development.In 2007-2023,shale oil and gas production in the United States increased from approximately 11.2×10^(4)tons of oil equivalent per day(toe/d)to over 300.0×10^(4)toe/d.In 2017,the shale oil and gas production exceeded the conventional oil and gas production in the country.In 2023,the contribution from shale plays to the total U.S.oil and gas production remained above 60%.The development of shale oil and gas has largely been driven by improvements in drilling and completion technologies,with much of the recent effort focused on“cube development”or“co-development”.Other efforts to improve productivity and efficiency include refracturing,enhanced oil recovery,and drilling of“U-shaped”wells.Given the significant resources base and continued technological improvements,shale oil and gas production will continue to contribute significant volumes to total U.S.hydrocarbon production.展开更多
文摘The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit (FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced loading, the refined finite element model for hot spot stress calculation, the combination of stress components, and fatigue damage assessment based on S-N curve.
文摘In view of the existing situation of gas field development, one kind of method to evaluate the production performance of gas production units (GPUs) was presented in this paper. Among the commonly used indicators of gas field development, we select 11 indicators from the three aspects of production task, gas reservoir management, and production technology. According to the principle of analytic network process (ANP), this paper introduced one kind of new method to get the weights of indicators. By means of the method of TOPSIS, it is easy to obtain the rankings for all the GPUs through calculating the weighted Euclidean distance between each GPU and the positive or negative ideal point. This evaluation method could constantly improve the management level of gas production units and deepen the delicacy management of gas field development.
文摘After many years of exploitation,onshore oil and gas resources are about to enter a recession period.Oil and gas will mainly come from oceans in the future.Generally speaking,the exploration and production(E&P)cost of oil from offshore is much higher than that of oil from onshore,so it is more sensitive to oil price.However,in recent years,oil price has been hovering at a low level for a long time,almost close to or even lower than the E&P cost of oil,which directly affects the development of oilfields.Besides the influence of oil price,some oilfields present the characteristics of marginal reserve scale,short peak production period and output rapidly declining.There leads to short economic life period and makes the economic benefit close to or lower than oilfield’s hurdle rate,which increases the difficulty of offshore oilfield development.As an important part of oilfield development,Floating Production Storage and Offloading unit,its investment mode and rent mode directly affect overall oilfield’s rate of return and the economic life.This paper chooses lease mode as the research object based on the analysis of investment mode,and further puts forward rent mode related with oil price through the analysis of traditional rent mode,and illustrates the advantages and disadvantages of various rent modes and their applicability so that the lessor chooses the right mode to achieve Win-Win with Oil Company and promotes the development of oilfields under low oil price.
基金supported by the International Foundation for Science(IFS)under Grant E/4955-1.
文摘The aims of this study were to investigate the food safety knowledge and practices of food handlers and to assess the sanitary conditions of attieke production units in the South of C?te d’Ivoire. A cross-sectional study was conducted during 4 months in 2012 in 7 localities and data were collected using questionnaire and observation checklist and microbiological analysis of hands. A total of 775 attieke production units were involved in this survey. Seventy-one percent (71%) were located on public domains and only 70 production units (9%) used septic tank as a mean of final deposal for liquid waste. Hygiene conditions and practices of food handlers in attieke production units were inadequate. The presence of specific microorganisms such as Staphylococcus aureus, Klebsiella pneumoniae, Enterobacter agglomerans, Citrobacter youngae, Klebsiella oxytoca and Citrobacter freundi was indicative of a degree of ignorance on the part of food handlers towards proper hygienic practices.
文摘Most measurements for beef improvement in South Africa are per individual (weaning weight, calving interval, growth rate, etc.). A measurement that expresses performance per constant unit, e.g. kilogram calf weaned per Large Stock Unit (LSU) can eventually be translated to kilogram calf produced per kg CO2 equivalent. A LSU is defined as a bovine requiring 75 MJ Metabolisable Energy (ME) per day. If more kilogram weaner calf can be produced per LSU (KgC/LSU), the carbon footprint of beef can be reduced. This study used breed average values to investigate the KgC/LSU for the 30 beef and dual purpose breeds in South Africa. The breeds were categorized in the following breed types: Sanga (indigenous to South Africa) Sanga derived, Zebu, Zebu derived, British and European. No relationship was found between cow weights and KgC/LSU, indicating that it is independent of cow weight between breeds. However, when the data is summarized into breed types, the Sanga and European breed types produce the least KgC/ LSU and Sanga derived breed types the most. This high value of the Sanga derived breeds is probably due to retained heterosis. Composite breeds are mostly intermediate to parental breeds for individual traits but superior for composite traits and KgC/LSU is a composite trait. These calculations were only done on breed averages. A genetic analysis on a breed level to estimate genetic parameters for this trait, and its genetic correlations with other traits now needs to be done before a decision can be taken whether selection for KgC/LSU will be feasible. The ultimate aim with a trait like this is to reduce the carbon footprint of weaner calf production since more kilogram calf will be produced per LSU (constant feed unit).
基金Under the auspices of National Natural Science Foundation of China (No. 40971062)China Postdoctoral ScienceFundation (No. 20100480441)
文摘Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook,this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting factors.The results show that:1) During 1980 to 2007,total grain production increased from 3.20 × 108 t to 5.02 × 108 t in China,with annual increasing rate of 1.68%.From the regional disparities,most of the regions present increasing trend of total grain production except for several regions with higher level of economic development;2) Grain sown area decreased from 1.17 × 108 ha in 1980 to 1.06 × 108 ha in 2007,which has negative effect on total grain production;3) The increase of grain yield per unit area caused by land use intensity changes contributed to the increase of total grain yield greatly.However,as the land use intensity showed that farmers pay more attention to labor-saving input but not yield-increasing input,the less enthusiasm of farmers in grain production may become an important constraint on fu-ture grain production increase in China;4) Based on the results,this paper proposed different land management poli-cies in different regions,for example,the government should protect cultivated land,promote large scale production.As to the less developed regions,the government should pay more attention to agricultural subsidies to promote farm-ers' enthusiasm in grain production.
基金Project supported by special scientific research foundation for doctoral subjects
文摘The internal turret mooring system for oil production storage vessels is a developing type ofoffshore floating production system suitable for deep water and harsh environmental application. In this paper, some achievements in our research work are presented. The description includes: dynamic analysis of mooring system, research on performance of turret assembly, influence of vessel dimensions and hull forms on mooring performance, model tests under combined action of environmental forces in basin, and hull structural strength analysis.
文摘It is expected that by 2025 China will add a total ethylene production capacity of 12 Mt/a,and in the next decade the total ethylene capacity will reach 35―40 Mt/a.The grassroots 11 new steam cracking units slated for production by the end of 2022 are listed in the following Table.
基金Supported by the National Natural Science Foundation of China(21376185)
文摘A novel rule-based model for multi-stage multi-product scheduling problem(MMSP)in batch plants with parallel units is proposed.The scheduling problem is decomposed into two sub-problems of order assignment and order sequencing.Firstly,hierarchical scheduling strategy is presented for solving the former sub-problem,where the multi-stage multi-product batch process is divided into multiple sequentially connected single process stages,and then the production of orders are arranged in each single stage by using forward order assignment strategy and backward order assignment strategy respectively according to the feature of scheduling objective.Line-up competition algorithm(LCA)is presented to find out optimal order sequence and order assignment rule,which can minimize total flow time or maximize total weighted process time.Computational results show that the proposed approach can obtain better solutions than those of the literature for all scheduling problems with more than 10 orders.Moreover,with the problem size increasing,the solutions obtained by the proposed approach are improved remarkably.The proposed approach has the potential to solve large size MMSP.
文摘The article describes funding models in Germany,France,UK and in Poland.The second part of the article concentrates on entrepreneurial implications and the context.At the end of the article of financing path is described including public funding opportunities in Europe from a game developers’perspective.
文摘Ruby—the country’s first seriescosmetics The Ruby Beauty Parlor andCosmetics School is the first of its kind inChina. The skin-care and make-upmethods it has applied are still popular.Among the gifts presented to queenElizabeth Ⅱ of Britain, British PrimeMinister Mrs. Thatcher and RussianPresident Gorbachev by the Chinesegovernment, there was Ruby. According to market surveys andthe conclusions of beauty culture, workingwomen in modern society with their fastrhythm of life and exquisite tastes arefastidious in selecting cosmetics. To meettheir special needs, Ruby’s white
文摘Capella油田是哥伦比亚南部重要的稠油油田,目前处于开发生产阶段,为了油田的稳产增产,需频繁对油井进行干预。Flush by Unit具有操作简单、移动高效、作业时间缩短、安全事故少等优点,作为试点引入了Flush by Unit为该油田的浅井提供修井服务,以降低桶油成本。本文介绍了Flush by Unit的结构组成、使用范围、现场使用效果,与传统修井机相比,可以大幅降低作业时间和成本,为后续规模使用Flush by Unit进行常规修井提供了依据,也为油田的增产稳产带来了机遇。
文摘The integrated circuit (IC) manufacturing process is capital intensive and complex. The production process of unit product (or die, as it is commonly referred to) takes several weeks. Semiconductor factories (fabs) continuously attempt to improve their productivity, as measured in output and cycle time (or mean flow time). The conflicting objective of producing maximum units at minimal production cycle time and at the highest quality, as measured by die yield, is discussed in this paper. The inter-related effects are characterized, and a model is proposed to address this multi-objective function. We then show that, with this model, die cost can be optimized for any given operating conditions of a fab. A numerical example is provided to illustrate the practicality of the model and the proposed optimization method.
基金supported by the State of Texas Advanced Resource Recovery(STARR)programthe Bureau of Economic Geology's Tight Oil Resource Assessment(TORA)Mudrock Systems Research Laboratory(MSRL)consortia。
文摘We present a systematic summary of the geological characteristics,exploration and development history and current state of shale oil and gas in the United States.The hydrocarbon-rich shales in the major shale basins of the United States are mainly developed in six geological periods:Middle Ordovician,Middle-Late Devonian,Early Carboniferous(Middle-Late Mississippi),Early Permian,Late Jurassic,and Late Cretaceous(Cenomanian-Turonian).Depositional environments for these shales include intra-cratonic basins,foreland basins,and passive continental margins.Paleozoic hydrocarbon-rich shales are mainly developed in six basins,including the Appalachian Basin(Utica and Marcellus shales),Anadarko Basin(Woodford Shale),Williston Basin(Bakken Shale),Arkoma Basin(Fayetteville Shale),Fort Worth Basin(Barnett Shale),and the Wolfcamp and Leonardian Spraberry/Bone Springs shale plays of the Permian Basin.The Mesozoic hydrocarbon-rich shales are mainly developed on the margins of the Gulf of Mexico Basin(Haynesville and Eagle Ford)or in various Rocky Mountain basins(Niobrara Formation,mainly in the Denver and Powder River basins).The detailed analysis of shale plays reveals that the shales are different in facies and mineral components,and"shale reservoirs"are often not shale at all.The United States is abundant in shale oil and gas,with the in-place resources exceeding 0.246×10^(12)t and 290×10^(12)m^(3),respectively.Before the emergence of horizontal well hydraulic fracturing technology to kick off the"shale revolution",the United States had experienced two decades of exploration and production practices,as well as theory and technology development.In 2007-2023,shale oil and gas production in the United States increased from approximately 11.2×10^(4)tons of oil equivalent per day(toe/d)to over 300.0×10^(4)toe/d.In 2017,the shale oil and gas production exceeded the conventional oil and gas production in the country.In 2023,the contribution from shale plays to the total U.S.oil and gas production remained above 60%.The development of shale oil and gas has largely been driven by improvements in drilling and completion technologies,with much of the recent effort focused on“cube development”or“co-development”.Other efforts to improve productivity and efficiency include refracturing,enhanced oil recovery,and drilling of“U-shaped”wells.Given the significant resources base and continued technological improvements,shale oil and gas production will continue to contribute significant volumes to total U.S.hydrocarbon production.