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
To achieve the goals of emission peak and carbon neutrality,significant effort is invested to accelerate the energy transition,with a focus on the development and utilization of renewable energy,as well as the upgradi...To achieve the goals of emission peak and carbon neutrality,significant effort is invested to accelerate the energy transition,with a focus on the development and utilization of renewable energy,as well as the upgrading of conventional units.Within this context,this paper proposes an innovative concept,known as the integrated energy production unit(IEPU),providing a variety of energy products and flexible adjustment functions for power systems with high penetration of non-hydro renewable energy.In the IEPU framework,a photovoltaic(PV)power plant is installed to produce electricity;CO_(2) capture technology is applied to the existing coal-fired power plant with biomass co-combustion.The generated CO_(2) is used to synthesize methane or methanol with hydrogen through electrolysis.First,the operational principle and advantages of this concept are illustrated.Then,a simplified model is built to provide an optimal configuration scheme of equipment capacity.Finally,the potential contribution of IEPU to the operational flexibility of the power system is also analyzed.展开更多
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
为解决半潜式平台浮体结构建造过程中产生的累积偏差问题,以陵水17-2浮式生产装置(Floating Production Unit,FPU)为研究对象,根据建造过程中产品精度控制要素的偏差传递关系建立浮体结构建造精度数据链模型。根据精度数据链中各关联要...为解决半潜式平台浮体结构建造过程中产生的累积偏差问题,以陵水17-2浮式生产装置(Floating Production Unit,FPU)为研究对象,根据建造过程中产品精度控制要素的偏差传递关系建立浮体结构建造精度数据链模型。根据精度数据链中各关联要素之间的逻辑关系,研究开发面向FPU浮体结构建造精度过程控制的数据管理系统,可实现数据采集、数据分析、问题处理等功能之间的数据流向、数据加工、数据存储、数据重用的关联和解耦,以及实际生产过程的精度控制映射流程。研究成果对于其他类型海洋平台结构物的建造也具有一定的扩展适应性。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
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
The experiment was conducted to investigate the heat transfer performance of supercritical CO_2 in a casing heat exchanger by comparing their heat transfer,entropy production unit number,non-dimensional entropy produc...The experiment was conducted to investigate the heat transfer performance of supercritical CO_2 in a casing heat exchanger by comparing their heat transfer,entropy production unit number,non-dimensional entropy production rate and field synergy factor.The results show that both heat transfer and entropy production unit number in four tubes decrease with water temperature increasing.Heat transfer and entropy production unit number in multiple tubes( i. e.,triple straight tube and double helix tube) is higher than their single counterparts; the non-dimensional entropy production rate increases with water temperature. Non-dimensional entropy production rate of triple straight tube and double helix tube is far below the single tube. Field synergy factor of double helix tube is much higher than that of the triple straight tube under the same condition. Further experiment was carried out in double helix tube,under various CO_2 pressure and inlet water temperature,the results are analyzed and reported in this paper.展开更多
The authors performed economic assessment of producing biodiesel at pilot scale using used cooking oil as feed-oil in a Bio-Pro 380 EX biodiesel reactor. The overall results suggest that the biodiesel production using...The authors performed economic assessment of producing biodiesel at pilot scale using used cooking oil as feed-oil in a Bio-Pro 380 EX biodiesel reactor. The overall results suggest that the biodiesel production using used cooking oil is a viable project even at large or medium scale. The payback period for producing biodiesel at a pilot scale of 31,320 liters per year was 1.5 years, which was 1 month longer than the payback period for a large plant capacity of 66,000 liters per year. The study demonstrated that the unit selling price and unit production cost are sensitive to the economic feasibility of biodiesel production, since price variations of BWP 1 result in at least a 13% increase and 12% decrease in profit, respectively. The study further revealed that feed-oil (used cooking oil) was the most expensive among all the inputs accounting for 61%, followed by methanol and direct labour with 19% and 13% respectively. The overall energy recorded to produce approximately 360 liters of biodiesel contributed to 2% only, suggesting that Bio-Pro 380 EX biodiesel reactor is relatively a low energy intensity processor. The situation is suitable for the promotion of biodiesel particularly in countries where initiatives to stimulate the development of biofuels are at its infant stage Botswana included.展开更多
Chinese textile companies might see Thursday--the first day of 2009--as the beginning of an unfettered era of free trade,but the outlook is clouded by weakening demand and rising protectionism amid the financial crisi...Chinese textile companies might see Thursday--the first day of 2009--as the beginning of an unfettered era of free trade,but the outlook is clouded by weakening demand and rising protectionism amid the financial crisis. Many textile companies cut exports to the lowest level in recent years.Some even failed to use up the quotas acquired before the third quarter.Shrinking orders in the fourth quarter and dim prospects for the year 2009 would mean a"tight"year for textile makers.This report contains information on the export status of original US quota-展开更多
Methanol to aromatics produces multiple products,resulting in a limited selectivity of xylene.Aromatics upgrading is an effective way to produce more valuable xylene product,and different feed ratios generate discrepa...Methanol to aromatics produces multiple products,resulting in a limited selectivity of xylene.Aromatics upgrading is an effective way to produce more valuable xylene product,and different feed ratios generate discrepant product distributions.This work integrates the aromatics separation with toluene disproportionation,transalkylation of toluene and trimethylbenzene,and isomerization of xylene and trimethylbenzene.Exergy and exergoeconomic analyses are conducted to give insights in the splitting ratios of benzene,toluene and heavy aromatics for aromatics upgrading.First,a detailed simulation model is developed in Aspen HYSYS.Then,300 splitting ratio sets of benzene and toluene for conversion are studied to investigate the process performances.The results indicate that there are different preferences for the splitting ratios of benzene and toluene in terms of exergy and exergoeconomic performances.The process generates lower total exergy destruction when the splitting ratio of toluene varies between 0.07 and 0.18,and that of benzene fluctuates between 0.55 and 0.6.Nevertheless,the process presents lower total product unit cost with the splitting ratio of toluene less than 0.18 and that of benzene fluctuating between 0.44 and 0.89.Besides,it is found that distillation is the biggest contributor to the total exergy destruction,accounting for 94.97%.展开更多
Floating liquefied natural gas （LNG） plants are gaining increasing attention in offshc,re energy exploitation. The effects of the periodically osciUatory motion on the fluid flow in all processes on the oil＂shore p...Floating liquefied natural gas （LNG） plants are gaining increasing attention in offshc,re energy exploitation. The effects of the periodically osciUatory motion on the fluid flow in all processes on the oil＂shore plant are very complicated and require detailed thermodynamic and hydrodynamic analyses. In this paper, numerical simula- tions are conducted by computational fluid dynamics （CFD） code combined with user defined function （UDF） in order to understand the periodically oscillating pressure characteristics of inviscid flow in the rolling pipe. The computational model of the circular pipe flow is established with the excitated rolling motion, at the excitated frequencies of 1-4rad/s, and the excitated amplitudes of 3^-15~, respectively. The influences of flow velocities and excitated conditions on pressure characteristics, including mean pressure, frequency and amplitude are systematically investigalted. It is found that the pressure fluctuation of the inviscid flow remains almost constant at different flow velocities. The amplitude of the pressure fluctuation increases with the increasing of the excitated amplitude, and decreases with the increasing of the excitated frequency. It is also found that the period of the pressure fluctuation varies with the excitated frequency. Furthermore, theoretical analyses of the flow in the rolling circular pipe are conducted and the results are found in qualitative agreement with the numerical simulations.展开更多
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.
基金supported by the Science and Technology Project of State Grid Corporation of China:Feasibility study on integrated energy production unit facing the goal of carbon neutrality(SGJSJY00FKJS2100121).
文摘To achieve the goals of emission peak and carbon neutrality,significant effort is invested to accelerate the energy transition,with a focus on the development and utilization of renewable energy,as well as the upgrading of conventional units.Within this context,this paper proposes an innovative concept,known as the integrated energy production unit(IEPU),providing a variety of energy products and flexible adjustment functions for power systems with high penetration of non-hydro renewable energy.In the IEPU framework,a photovoltaic(PV)power plant is installed to produce electricity;CO_(2) capture technology is applied to the existing coal-fired power plant with biomass co-combustion.The generated CO_(2) is used to synthesize methane or methanol with hydrogen through electrolysis.First,the operational principle and advantages of this concept are illustrated.Then,a simplified model is built to provide an optimal configuration scheme of equipment capacity.Finally,the potential contribution of IEPU to the operational flexibility of the power system is also analyzed.
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.
文摘为解决半潜式平台浮体结构建造过程中产生的累积偏差问题,以陵水17-2浮式生产装置(Floating Production Unit,FPU)为研究对象,根据建造过程中产品精度控制要素的偏差传递关系建立浮体结构建造精度数据链模型。根据精度数据链中各关联要素之间的逻辑关系,研究开发面向FPU浮体结构建造精度过程控制的数据管理系统,可实现数据采集、数据分析、问题处理等功能之间的数据流向、数据加工、数据存储、数据重用的关联和解耦,以及实际生产过程的精度控制映射流程。研究成果对于其他类型海洋平台结构物的建造也具有一定的扩展适应性。
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
基金Hujiang Foundation of China(No.D14003)Yangtze River Delta Technology Joint Research,China(No.10195811000)
文摘The experiment was conducted to investigate the heat transfer performance of supercritical CO_2 in a casing heat exchanger by comparing their heat transfer,entropy production unit number,non-dimensional entropy production rate and field synergy factor.The results show that both heat transfer and entropy production unit number in four tubes decrease with water temperature increasing.Heat transfer and entropy production unit number in multiple tubes( i. e.,triple straight tube and double helix tube) is higher than their single counterparts; the non-dimensional entropy production rate increases with water temperature. Non-dimensional entropy production rate of triple straight tube and double helix tube is far below the single tube. Field synergy factor of double helix tube is much higher than that of the triple straight tube under the same condition. Further experiment was carried out in double helix tube,under various CO_2 pressure and inlet water temperature,the results are analyzed and reported in this paper.
文摘The authors performed economic assessment of producing biodiesel at pilot scale using used cooking oil as feed-oil in a Bio-Pro 380 EX biodiesel reactor. The overall results suggest that the biodiesel production using used cooking oil is a viable project even at large or medium scale. The payback period for producing biodiesel at a pilot scale of 31,320 liters per year was 1.5 years, which was 1 month longer than the payback period for a large plant capacity of 66,000 liters per year. The study demonstrated that the unit selling price and unit production cost are sensitive to the economic feasibility of biodiesel production, since price variations of BWP 1 result in at least a 13% increase and 12% decrease in profit, respectively. The study further revealed that feed-oil (used cooking oil) was the most expensive among all the inputs accounting for 61%, followed by methanol and direct labour with 19% and 13% respectively. The overall energy recorded to produce approximately 360 liters of biodiesel contributed to 2% only, suggesting that Bio-Pro 380 EX biodiesel reactor is relatively a low energy intensity processor. The situation is suitable for the promotion of biodiesel particularly in countries where initiatives to stimulate the development of biofuels are at its infant stage Botswana included.
文摘Chinese textile companies might see Thursday--the first day of 2009--as the beginning of an unfettered era of free trade,but the outlook is clouded by weakening demand and rising protectionism amid the financial crisis. Many textile companies cut exports to the lowest level in recent years.Some even failed to use up the quotas acquired before the third quarter.Shrinking orders in the fourth quarter and dim prospects for the year 2009 would mean a"tight"year for textile makers.This report contains information on the export status of original US quota-
基金the National Natural Science Foundation of China(Grant No.21736008)the National Key Research and Development Program of China(Grant No.2018YFB0604803).
文摘Methanol to aromatics produces multiple products,resulting in a limited selectivity of xylene.Aromatics upgrading is an effective way to produce more valuable xylene product,and different feed ratios generate discrepant product distributions.This work integrates the aromatics separation with toluene disproportionation,transalkylation of toluene and trimethylbenzene,and isomerization of xylene and trimethylbenzene.Exergy and exergoeconomic analyses are conducted to give insights in the splitting ratios of benzene,toluene and heavy aromatics for aromatics upgrading.First,a detailed simulation model is developed in Aspen HYSYS.Then,300 splitting ratio sets of benzene and toluene for conversion are studied to investigate the process performances.The results indicate that there are different preferences for the splitting ratios of benzene and toluene in terms of exergy and exergoeconomic performances.The process generates lower total exergy destruction when the splitting ratio of toluene varies between 0.07 and 0.18,and that of benzene fluctuates between 0.55 and 0.6.Nevertheless,the process presents lower total product unit cost with the splitting ratio of toluene less than 0.18 and that of benzene fluctuating between 0.44 and 0.89.Besides,it is found that distillation is the biggest contributor to the total exergy destruction,accounting for 94.97%.
文摘Floating liquefied natural gas （LNG） plants are gaining increasing attention in offshc,re energy exploitation. The effects of the periodically osciUatory motion on the fluid flow in all processes on the oil＂shore plant are very complicated and require detailed thermodynamic and hydrodynamic analyses. In this paper, numerical simula- tions are conducted by computational fluid dynamics （CFD） code combined with user defined function （UDF） in order to understand the periodically oscillating pressure characteristics of inviscid flow in the rolling pipe. The computational model of the circular pipe flow is established with the excitated rolling motion, at the excitated frequencies of 1-4rad/s, and the excitated amplitudes of 3^-15~, respectively. The influences of flow velocities and excitated conditions on pressure characteristics, including mean pressure, frequency and amplitude are systematically investigalted. It is found that the pressure fluctuation of the inviscid flow remains almost constant at different flow velocities. The amplitude of the pressure fluctuation increases with the increasing of the excitated amplitude, and decreases with the increasing of the excitated frequency. It is also found that the period of the pressure fluctuation varies with the excitated frequency. Furthermore, theoretical analyses of the flow in the rolling circular pipe are conducted and the results are found in qualitative agreement with the numerical simulations.
