Gastric cancer is a global public health burden, nearly one million new cases are diagnosed per year worldwide, of which 44% of cases occur in China. The prognosis of gastric cancer varies remarkably by the stage of c...Gastric cancer is a global public health burden, nearly one million new cases are diagnosed per year worldwide, of which 44% of cases occur in China. The prognosis of gastric cancer varies remarkably by the stage of cancer, and most of the patients in China are diagnosed at advanced stages, resulting in poor prognoses. Effective strategies to reduce the burden of gastric cancer include primary prevention through testing and treatment of Helicobacter pylori(H. pylori) and secondary prevention by screening and early detection. Although many countries have issued management guidelines and consensus reports concerning these strategies, the limited availability of healthcare resources often precludes their widespread implementation. Therefore, assessing the costs, benefits, and harms of population-based intervention measures through health economic evaluation is necessary for informed health policy decisions. Accordingly, we synthesize management approaches from different countries on H. pylori eradication and endoscopic screening, and also summarize recent advancements in health economic evaluations on population-based preventive strategies. The goal of the review is to provide empirical evidence supporting optimal resource allocation, maximizing benefits for the population, and ultimately reducing the burden of gastric cancer.展开更多
Because forecasting a development program during the target selection phase of exploration for coalbed methane (CBM) is impossible, the conventional method that relies on a conceptual (or detailed) development pro...Because forecasting a development program during the target selection phase of exploration for coalbed methane (CBM) is impossible, the conventional method that relies on a conceptual (or detailed) development pro- gram cannot be used during the economic evaluation of CBM resources. Hence, this study focuses on establishing an economic evaluation model based on the characteristics of the target selection phase. The discounted cashflow method is applied to the construction of the model with the assumption that there is a uniform distribution of produc- tion wells. The computational error generated by the assumption is corrected by introducing a correction factor based on the production profile of single CBM wells. The case study demonstrates that the blocks lacking economic value can be screened out, and the most advantageous targets can be found by computing the resource values in the best- and worst-case scenarios. This technique can help to reduce wasted investments and improve the quality of decision-making in selecting targets for exploration.展开更多
Objective:This study evaluated the feasibility of different cervical cancer screening strategies in urban China.Methods:A Markov model was constructed to simulate a hypothetical cohort of 100,000 females aged 30-59 ye...Objective:This study evaluated the feasibility of different cervical cancer screening strategies in urban China.Methods:A Markov model was constructed to simulate a hypothetical cohort of 100,000 females aged 30-59 years in a 20-year period.Screening strategies included liquid-based cytology(LBC)every three years,human papillomavirus(HPV)DNA testing every three and five years,respectively,and a combination of HPV DNA testing and LBC(HPV+LBC)every three and five years,respectively.Model outcomes included cumulative incidence over 20 years,cumulative risk of cervical cancer,costs,life year saved(LYS),quality-adjusted life years(QALYs)and benefits.The cost-effectiveness ratios(CERs),incremental cost-effectiveness ratios(ICERs),costutility ratios(CURs),and benefit-cost ratios(BCRs)were used as outcomes in the health economic evaluation analysis.Univariate sensitivity analyses were performed to examine the stability of the results.Results:The cumulative incidence of the five screening strategies ranged from 833.02 to 1,158.07 cases per100,000 females.HPV DNA testing was most effective in reducing the cumulative risk of cervical cancer,saving life years and QALYs and gaining benefits.The CERs of HPV DNA testing every three and five years,and LBC every three years were considered to be very cost-effective if they were below China's GDP per capita.The CERs of HPV+LBC were considered to be cost-effective if they were below three times GDP per capita.The incremental cost-effectiveness analysis showed that HPV DNA testing every three and five years,LBC every three years and HPV+LBC every five years were dominant strategies.Conclusions:The findings of this study indicated that HPV DNA testing every five years or LBC every three years should be recommended in urban China.展开更多
The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This stu...The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.展开更多
Hydraulic fracturing is among the approaches used to optimize production from a gas condensate reservoir. A detailed economic analysis is required to evaluate the profitability and feasibility of hydraulic fracturing ...Hydraulic fracturing is among the approaches used to optimize production from a gas condensate reservoir. A detailed economic analysis is required to evaluate the profitability and feasibility of hydraulic fracturing as an optimization option in a gas condensate reservoir operating below dewpoint. The objective of this research is to evaluate the economic benefits derivable from the use of hydraulic fracturing to improve gas and liquid recovery from a gas condensate reservoir operating below dewpoint. This research considers the use of four profit indicators to ascertain the profitability of hydraulic fracturing in a gas condensate reservoir operating below dewpoint by increasing the fracture halflength, fracture width and fracture permeability. The production data of the reservoir was obtained and the economic calculations done on excel spreadsheet and plots generated. The four profit indicators considered in the research are Net Present Value, Payout, Discounted Cash Flow Rate of Return and Profit per Dollar Invested. The economic justification was done by carrying out a comparative economic analysis from the result obtained when the reservoir of study was unfractured with that obtained when the reservoir was fractured at various fracture parameters. The economic analysis was done considering a royalty and tax rate of 18.5% and 30% respectively and a gas price of $2/MSCF and condensate price of $30/bbl. This is done so as to find out if the additional cost of hydraulic fracturing can be offset by the recovery from the reservoir when its pressure declined below dewpoint. The result obtained showed that the additional recovery due to hydraulic fracturing by increasing the fracture halflength, fracture width and fracture permeability was not enough to justify the application of hydraulic fracturing when the reservoir pressure declined below dewpoint.展开更多
Objective To evaluate the economy of detecting gastric cancer by electronic gastroscope in Chinese natural population of different ages and genders.Methods A Markov model was constructed for the population,including b...Objective To evaluate the economy of detecting gastric cancer by electronic gastroscope in Chinese natural population of different ages and genders.Methods A Markov model was constructed for the population,including both men and women of different ages.The model cycle was one year and the simulation time was 60 years.The cost-effectiveness of electronic gastroscopy in detecting gastric cancer of general population in China was analyzed from the perspective of the whole society,and the stability of the results was verified by sensitivity analysis.Results and Conclusion For the general population,the incremental cost-effectiveness ratio(ICER)of gastric cancer screening from the age of 50 is 50143 yuan/QALY(quality-adjusted life-year),which is less than two times of per capita gross domestic product(GDP)compared with the screening from the age of 55.For men who start gastric cancer screening at the age of 50,the ICER is 38525 yuan/QALY,which is less than two times of per capita GDP,and it is economical.For women who start the screening from the age of 55,the ICER is 47814 yuan/QALY,which is less than two times of per capita GDP,so it is economical.The results of sensitivity analysis are consistent with the conclusions of basic analysis,and the results of basic analysis are stable.For the general population,it is more economical to start gastric cancer screening from the age of 50,while for men and women,it is more economical to start gastric cancer screening from the age of 50 and 55,respectively.展开更多
The rapid development of communication services in the power distribution network poses challenges for existing wireless communications,and the deployment of a fiber optic network is costly and difficult.The emerging ...The rapid development of communication services in the power distribution network poses challenges for existing wireless communications,and the deployment of a fiber optic network is costly and difficult.The emerging 5G technology has been piloted in power distribution networks,though the cost-effectiveness of its large-scale deployment remains unclear.This paper proposes an economic evaluation method for 5G planning in power distribution networks,considering the coupling relationship between power distribution and communication networks and the identification of important network nodes.First,the objective function to solve the planned number of 5G base stations is established.This is solved using the adaptive particle swarm algorithm and K-means algorithm.Second,the coupling relationship between the distribution and communication networks is discussed and quantified.The node importance of the coupling network is analyzed to identify the important nodes,and micro base stations or optical fibers are added to improve the reliability of the distribution network at the communication level.Finally,an economic evaluation index of 5G planning of the distribution network is established.The paper compares the economic solutions of 5G and 4G communications in city and town scenarios using the IEEE 123-node network as an example,and concludes that the economics of 5G are better than those of 4G.展开更多
The rice-duck ecological system is one of the major practices of the traditional Chinese agriculture. A study on the effect of reducing methane emission using this practice provided theoretical and practical basis for...The rice-duck ecological system is one of the major practices of the traditional Chinese agriculture. A study on the effect of reducing methane emission using this practice provided theoretical and practical basis for further development and utilization of this classical agricultural technique. The effect of reducing methane emission and the economic benefits of rice-duck ecological system were studied by carrying out a field experiment and by using economic methodology. The daily variation of CH4 emission in late rice paddy field was basically consistent with the daily variation of atmospheric temperature. The highest emission occurred at the full tillering stage of late rice with a rate of 24.1 or 32.2 or 40.5 mg m^-2 h^-1 in no-tillage area with duck and no-tillage area without duck and conventional-tillage area without duck, respectively. The inhibition of methane emission was apparently effective in the rice-duck ecological system during the initial tillering stage and the full tillering stage. Compared to the no-tillage area without duck, methane emission decreased by 2.333 g m^-2. Compared to the conventional-tillage area without duck, methane emission decreased by 4.723 g m^-2. During the production period of late rice, the amount of methane emission in no-tillage area with duck was 3.373 g m^-2 lesser than that of no-tillage area without duck, and 5.59 g m^-2 less than that of conventional-tillage without duck area. The economic significance was analyzed. Farmers adopting the rice-duck ecological system obtained 2 166 and 4 207 RMB yuan ha^-1 more income than those who adopted a no-tillage without duck technique or conventional-tillage without duck technique, respectively. In addition to the reduction of the environmental pollution by methane emission, the farmers who adopted the rice-duck ecological system achieved economic benefits of 5 000 RMB yuan ha^-1, which was 2 206 and 4 274 RMB yuan ha^-1 more than those who adopted a no-tillage without duck technique and a conventional-tillage without duck technique, respectively. The rice-duck ecological system not only increased the economic benefits for farmers, but also reduced methane emission in rice paddy field. A sustainable agricultural production mode was formed.展开更多
An increasing number of U.S.apple growers are now interested in using harvest platforms to increase harvest productivity,expand labor pool,and alleviate tough working conditions.To maximize benefits,functions of thinn...An increasing number of U.S.apple growers are now interested in using harvest platforms to increase harvest productivity,expand labor pool,and alleviate tough working conditions.To maximize benefits,functions of thinning,pruning&training,and infield sorting have been or are to be incorporated into harvest platforms.Though growers are most concerned with economic benefits,few cost-benefit studies had been conducted on different platforms.In the meantime,economic analysis procedure is complex and each analysis is for one specific machine(not for general purposes).No software has been developed as a general and ready-to-use tool for growers and researchers for the platform economic analysis.In this study,platforms,both available on the marketplace and developed in lab as pilot trials,were reviewed.Costs and benefits models were then established,based on which multi-purpose apple harvest platform economic evaluation software(iMPAHP)was developed(capable of evaluating a wide variety of apple harvest platforms).A case study(machine cost of$100000,accommodating 6 workers,processing apple incidence of 10%with 90%sort-out rate,and harvest,thinning,and pruning&training productivity increase by 40%,50%,and 60%,respectively)based on iMPAHP demonstrated that infield sorting,harvest,thinning,and pruning and training accounted for 48.4%,23.9%,14.3%,and 13.4%of the total benefits,respectively.In the case that the platform was in all-four-purpose-application,the net present value(NPV)analysis of a 10-year investment showed a positive return of$60547.However,without infield sorting function,the NPV resulted in a negative value,indicating a loss for the machine investment.Though incorporating the modular infield sorting system certainly increased the overall machine investment by$30000,the benefits outweighed the costs.展开更多
A reverse osmosis (RO) desalination system coupled with tidal energy is proposed. The mechanical energy produced by the tidal energy through hydraulic turbine is directly used to drive the RO unit. The system perfor...A reverse osmosis (RO) desalination system coupled with tidal energy is proposed. The mechanical energy produced by the tidal energy through hydraulic turbine is directly used to drive the RO unit. The system performances and the water cost of the conventional and tidal energy RO systems are compared. It is found that the proposed tidal energy RO system can save water cost in the range of 31.0%-41.7% in comparison with the conventional RO system. There is an optimum feed pressure that leads to the lowest water cost. The tidal RO system can save more costs at a high feed pressure or a high water recovery rate. The optimum feed pressure of the tidal energy RO system is higher than that of the conventional RO system. The longer lifetime of the tidal energy RO system can save even more water cost. When the site development cost rate is lower than 40%, the water cost of the tidal energy RO system will be lower than that of the conventional RO system. The proposed technology will be an effective alternative desalination method in the future.展开更多
Scoring the technologies in competition for the NRG Canada’s Oil Sands Innovation Alliance Carbon XPRIZE required an economic evaluation to estimate the value created through the conversion of CO_(2) emissions into p...Scoring the technologies in competition for the NRG Canada’s Oil Sands Innovation Alliance Carbon XPRIZE required an economic evaluation to estimate the value created through the conversion of CO_(2) emissions into products.Across all of the Teams participating in the competition,58 different materials were consumed and produced.Standardized prices and market sizes needed to be established for each of these materials to ensure a consistent evaluation across all Teams.The Standards Data Set(SDS)was created as a standardized database of economic data used in the competition.The rationale for the SDS project and the methodology for researching each material is described.Ultimately,credible material definitions using the SDS methodology were created for all materials,and some research and methodological customization were required for materials that did not have credible,publicly available market data.The methodologies for establishing credible values and market sizes for concrete,concrete admixtures and syngas are highlighted as examples of materials whose value and markets are not easily defined.展开更多
This paper describes a new method which is different with the shadow price method to evaluate the economic benefits of the water source project. The approach is to take the water source as a constraint on the regiona...This paper describes a new method which is different with the shadow price method to evaluate the economic benefits of the water source project. The approach is to take the water source as a constraint on the regional economic development, calculate the difference between the generaded when the water source project is in operation and the gross product generated when the project is nonexistent, and then review the economic benefits on the project. For this purpose, we have constructed an input-output linear programming model and compiled a compatible using the routines for solving the input-output linear programming model. The above models and the routines have been used in paractical calculation of economic benefits of a water source project for a region. The computation result are satisfactory.展开更多
Energy storage system is an important means to improve the flexibility and safety of traditional power system,but it has the problem of high cost and unclear value recovery path.In this paper,the typical application s...Energy storage system is an important means to improve the flexibility and safety of traditional power system,but it has the problem of high cost and unclear value recovery path.In this paper,the typical application scenarios of energy storage system are summarized and analyzed from the perspectives of user side,power grid side and power generation side.Based on the typical application scenarios,the economic benefit assessment framework of energy storage system including value,time and efficiency indicators is proposed.Typical battery energy storage projects are selected for economic benefit calculation according to different scenarios,and key factors are selected for sensitivity analysis.Finally,the key factors affecting economic benefit of the energy storage system are analyzed.展开更多
The invasive fall armyworm Spodoptera frugiperda(J.E.Smith)invaded Asia in 2018,colonizing the tropical and southern subtropical regions as well as migrating with the monsoons into Northeast Asia during spring and sum...The invasive fall armyworm Spodoptera frugiperda(J.E.Smith)invaded Asia in 2018,colonizing the tropical and southern subtropical regions as well as migrating with the monsoons into Northeast Asia during spring and summer.This has resulted in widespread infestations,with significant impacts on maize production in various Asian countries.Previous studies have shown that the invasion of this pest can alter the species relationships of maize pests,but the actual impact on maize pest management is still unclear.This study investigated the changes in maize pest occurrence and pesticide use in the annual breeding areas of S.frugiperda in Yunnan Province and the Guangxi Zhuang Autonomous Region of China during 2017-2021,based on surveys and interviews with small farmers in maize production.The results showed that S.frugiperda has emerged as the dominant species among maize pests after invasion and colonization,replacing traditional pests such as Ostrinia furnacalis,Spodoptera litura,Agrotis ypsilon,and Rhopalosiphum maidis.The variety of pesticides used for maize pest control has changed from chlorpyrifos,lambda-cyhalothrin,and acetamiprid to emamectin benzoate-based pesticides with high effectiveness against S.frugiperda.Furthermore,the frequency of maize pest chemical applications has increased from an average of 5.88 to 7.21 times per season,with the amounts of pesticides used in summer and autumn maize being significantly higher than in winter and spring maize,thereby increasing application costs by more than 35%.The results of this study clarified the impact of S.frugiperda invasion on maize pest community succession and chemical pesticide use in tropical and south subtropical China,thereby providing a baseline for modifying the regional control strategies for maize pests after the invasion of this relatively new pest.展开更多
This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristic...This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption (PSA), chemical absorption (CA), and membrane absorption (MA). Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.展开更多
In this work,a model of hydrogen production by double chemical looping is introduced.The efficiency benefit obtained was investigated.The chemical looping hydrogen generation unit is connected in series to the downstr...In this work,a model of hydrogen production by double chemical looping is introduced.The efficiency benefit obtained was investigated.The chemical looping hydrogen generation unit is connected in series to the downstream of a chemical looping gasification unit as an additional system for 100 MWh coal gasification,with the function of supplementary combustion to produce hydrogen.Using Aspen Plus software for process simulation,the production of H_(2) and N_(2) in the series system is higher than that in the independent Chemical looping gasification and Chemical looping hydrogen generation systems,and the production of hydrogen is approximately 25.63%and 12.90%higher,respectively;The study found that when the gasification temperature is 900C,steam-carbon ratio is 0.84 and oxygen-carbon ratio is 1.5,the hydrogen production rate of the system was the maximum.At the same time,through heat exchange between logistics,high-pressure steam at 8.010×10^(4) kg·h^(-1) and medium-pressure steam at 1.101×10^(4) kg·h^(-1) are generated,and utility consumption is reduced by 61.58%,with utility costs decreasing by 48.69%.An economic estimation study found that the production cost of ammonia is 108.66 USD(t NH_(3))^(-1).Finally,cost of equipment is the main factors influencing ammonia production cost were proposed by sensitivity analysis.展开更多
LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incre...LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incremental and sensitivity analysis to determine whether it is feasible to incorporate current battery technology into these machines. When revenue was taken into account, decreasing the amount of haulage in battery operated equipment by 5% or 200 kg per h amounts to a $4.0 × 10~4 loss of profit per year. On average it was found that using battery operated equipment generated $9.5 × 10~4 more in income annually, reducing the payback period from seven to two years to pay back the additional $1.0 × 10~5 investment of buying battery powered equipment over cheaper diesel equipment. Due to the estimated 5% increase in capital, it was observed that electric vehicles must possess a lifetime that is a minimum of one year longer than that of diesel equipment.展开更多
The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements.The traditional measures substantially increased the related costs for enterprises to reach...The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements.The traditional measures substantially increased the related costs for enterprises to reach standards.This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems.Typical three coking wastewater treatment processes in China were evaluated.Results showed that eutrophication dominantly contributed to the overall environmental effect.Improving effluent quality could significantly reduce the total environmental impact.In terms of an economic perspective,the price of raw materials was the main factor that affected the operating cost of comprehensive treatment.Based on subsystem analysis,the pretreatment stage accounted for the majority of environmental and cost burdens,respectively reaching 64%-78%and 64%-86%.Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8%and 57%,respectively,which was an effective way to improve the potential performance of coking wastewater treatment plants(WWTPs).展开更多
Objective To systematically review the published clinical and economic research on liposomal irinotecan in combination with 5-FU/LV for metastatic pancreatic ductal adenocarcinoma(mPDAC)at home and abroad.Methods PubM...Objective To systematically review the published clinical and economic research on liposomal irinotecan in combination with 5-FU/LV for metastatic pancreatic ductal adenocarcinoma(mPDAC)at home and abroad.Methods PubMed,Cochrane Library,Embase,CBM,CNKI,Wan Fang data,CRD database and health technology assessment official websites were searched to collect clinical and economic studies on liposomal irinotecan for mPDAC.Results and Conclusion Nine clinical studies and four economic studies were included.The result of clinical studies showed that liposomal irinotecan in combination with 5-FU/LV could extend survival with good drug compliance in patients with mPDAC who progressed on prior gemcitabine-based therapy.This agent represented a new treatment option for second-line chemotherapy in these patients.The results of the economic evaluations failed to reach a consistent conclusion due to different economic levels in various countries.展开更多
目的对经外周置入中心静脉导管(peripherally inserted central catheter,PICC)置管、维护及拔管的单项操作成本进行核算,为制定合理的操作收费价格提供依据。方法通过横断面调查,采用项目成本阶梯分摊法,于2019年1—5月在复旦大学附属...目的对经外周置入中心静脉导管(peripherally inserted central catheter,PICC)置管、维护及拔管的单项操作成本进行核算,为制定合理的操作收费价格提供依据。方法通过横断面调查,采用项目成本阶梯分摊法,于2019年1—5月在复旦大学附属肿瘤医院血管通路门诊测算PICC各单项操作人力成本、设备折旧费及未单独计价材料费,测算直接成本,并通过分摊测算间接成本,最后测算PICC置管、维护及拔管的单项操作成本。结果PICC置管、维护及拔管的各单项操作实际成本分别为(157.03±4.73)元、(33.66±3.04)元、(32.38±3.11)元,与上海市医疗机构对PICC各项操作的收费标准(分别为150元、30元、30元)基本相符。结论建议将PICC维护及拔管的操作收费纳入收费标准中,促进PICC输液技术的可持续发展并确保护理服务的持续供给。展开更多
基金supported in part by the Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support (No. ZLRK202325)a grant from National Key R&D Program of China (No. 2018YFC 1313105)。
文摘Gastric cancer is a global public health burden, nearly one million new cases are diagnosed per year worldwide, of which 44% of cases occur in China. The prognosis of gastric cancer varies remarkably by the stage of cancer, and most of the patients in China are diagnosed at advanced stages, resulting in poor prognoses. Effective strategies to reduce the burden of gastric cancer include primary prevention through testing and treatment of Helicobacter pylori(H. pylori) and secondary prevention by screening and early detection. Although many countries have issued management guidelines and consensus reports concerning these strategies, the limited availability of healthcare resources often precludes their widespread implementation. Therefore, assessing the costs, benefits, and harms of population-based intervention measures through health economic evaluation is necessary for informed health policy decisions. Accordingly, we synthesize management approaches from different countries on H. pylori eradication and endoscopic screening, and also summarize recent advancements in health economic evaluations on population-based preventive strategies. The goal of the review is to provide empirical evidence supporting optimal resource allocation, maximizing benefits for the population, and ultimately reducing the burden of gastric cancer.
基金funded by the Beijing Natural Science Foundation (9144033)the National Social Science Fund for Major Projects (11&ZD164)
文摘Because forecasting a development program during the target selection phase of exploration for coalbed methane (CBM) is impossible, the conventional method that relies on a conceptual (or detailed) development pro- gram cannot be used during the economic evaluation of CBM resources. Hence, this study focuses on establishing an economic evaluation model based on the characteristics of the target selection phase. The discounted cashflow method is applied to the construction of the model with the assumption that there is a uniform distribution of produc- tion wells. The computational error generated by the assumption is corrected by introducing a correction factor based on the production profile of single CBM wells. The case study demonstrates that the blocks lacking economic value can be screened out, and the most advantageous targets can be found by computing the resource values in the best- and worst-case scenarios. This technique can help to reduce wasted investments and improve the quality of decision-making in selecting targets for exploration.
基金supported by the National Health Commission of the People’s Republic of China (formerly the Health and Family Planning Commission) of China (No. 201502004)
文摘Objective:This study evaluated the feasibility of different cervical cancer screening strategies in urban China.Methods:A Markov model was constructed to simulate a hypothetical cohort of 100,000 females aged 30-59 years in a 20-year period.Screening strategies included liquid-based cytology(LBC)every three years,human papillomavirus(HPV)DNA testing every three and five years,respectively,and a combination of HPV DNA testing and LBC(HPV+LBC)every three and five years,respectively.Model outcomes included cumulative incidence over 20 years,cumulative risk of cervical cancer,costs,life year saved(LYS),quality-adjusted life years(QALYs)and benefits.The cost-effectiveness ratios(CERs),incremental cost-effectiveness ratios(ICERs),costutility ratios(CURs),and benefit-cost ratios(BCRs)were used as outcomes in the health economic evaluation analysis.Univariate sensitivity analyses were performed to examine the stability of the results.Results:The cumulative incidence of the five screening strategies ranged from 833.02 to 1,158.07 cases per100,000 females.HPV DNA testing was most effective in reducing the cumulative risk of cervical cancer,saving life years and QALYs and gaining benefits.The CERs of HPV DNA testing every three and five years,and LBC every three years were considered to be very cost-effective if they were below China's GDP per capita.The CERs of HPV+LBC were considered to be cost-effective if they were below three times GDP per capita.The incremental cost-effectiveness analysis showed that HPV DNA testing every three and five years,LBC every three years and HPV+LBC every five years were dominant strategies.Conclusions:The findings of this study indicated that HPV DNA testing every five years or LBC every three years should be recommended in urban China.
文摘The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.
文摘Hydraulic fracturing is among the approaches used to optimize production from a gas condensate reservoir. A detailed economic analysis is required to evaluate the profitability and feasibility of hydraulic fracturing as an optimization option in a gas condensate reservoir operating below dewpoint. The objective of this research is to evaluate the economic benefits derivable from the use of hydraulic fracturing to improve gas and liquid recovery from a gas condensate reservoir operating below dewpoint. This research considers the use of four profit indicators to ascertain the profitability of hydraulic fracturing in a gas condensate reservoir operating below dewpoint by increasing the fracture halflength, fracture width and fracture permeability. The production data of the reservoir was obtained and the economic calculations done on excel spreadsheet and plots generated. The four profit indicators considered in the research are Net Present Value, Payout, Discounted Cash Flow Rate of Return and Profit per Dollar Invested. The economic justification was done by carrying out a comparative economic analysis from the result obtained when the reservoir of study was unfractured with that obtained when the reservoir was fractured at various fracture parameters. The economic analysis was done considering a royalty and tax rate of 18.5% and 30% respectively and a gas price of $2/MSCF and condensate price of $30/bbl. This is done so as to find out if the additional cost of hydraulic fracturing can be offset by the recovery from the reservoir when its pressure declined below dewpoint. The result obtained showed that the additional recovery due to hydraulic fracturing by increasing the fracture halflength, fracture width and fracture permeability was not enough to justify the application of hydraulic fracturing when the reservoir pressure declined below dewpoint.
文摘Objective To evaluate the economy of detecting gastric cancer by electronic gastroscope in Chinese natural population of different ages and genders.Methods A Markov model was constructed for the population,including both men and women of different ages.The model cycle was one year and the simulation time was 60 years.The cost-effectiveness of electronic gastroscopy in detecting gastric cancer of general population in China was analyzed from the perspective of the whole society,and the stability of the results was verified by sensitivity analysis.Results and Conclusion For the general population,the incremental cost-effectiveness ratio(ICER)of gastric cancer screening from the age of 50 is 50143 yuan/QALY(quality-adjusted life-year),which is less than two times of per capita gross domestic product(GDP)compared with the screening from the age of 55.For men who start gastric cancer screening at the age of 50,the ICER is 38525 yuan/QALY,which is less than two times of per capita GDP,and it is economical.For women who start the screening from the age of 55,the ICER is 47814 yuan/QALY,which is less than two times of per capita GDP,so it is economical.The results of sensitivity analysis are consistent with the conclusions of basic analysis,and the results of basic analysis are stable.For the general population,it is more economical to start gastric cancer screening from the age of 50,while for men and women,it is more economical to start gastric cancer screening from the age of 50 and 55,respectively.
基金supported by the National Natural Sci-ence Foundation of China(No.52177114,61403127)Jiangxi Electric Power Co.,Ltd of State Grid(No.521820210005,521820220016).
文摘The rapid development of communication services in the power distribution network poses challenges for existing wireless communications,and the deployment of a fiber optic network is costly and difficult.The emerging 5G technology has been piloted in power distribution networks,though the cost-effectiveness of its large-scale deployment remains unclear.This paper proposes an economic evaluation method for 5G planning in power distribution networks,considering the coupling relationship between power distribution and communication networks and the identification of important network nodes.First,the objective function to solve the planned number of 5G base stations is established.This is solved using the adaptive particle swarm algorithm and K-means algorithm.Second,the coupling relationship between the distribution and communication networks is discussed and quantified.The node importance of the coupling network is analyzed to identify the important nodes,and micro base stations or optical fibers are added to improve the reliability of the distribution network at the communication level.Finally,an economic evaluation index of 5G planning of the distribution network is established.The paper compares the economic solutions of 5G and 4G communications in city and town scenarios using the IEEE 123-node network as an example,and concludes that the economics of 5G are better than those of 4G.
文摘The rice-duck ecological system is one of the major practices of the traditional Chinese agriculture. A study on the effect of reducing methane emission using this practice provided theoretical and practical basis for further development and utilization of this classical agricultural technique. The effect of reducing methane emission and the economic benefits of rice-duck ecological system were studied by carrying out a field experiment and by using economic methodology. The daily variation of CH4 emission in late rice paddy field was basically consistent with the daily variation of atmospheric temperature. The highest emission occurred at the full tillering stage of late rice with a rate of 24.1 or 32.2 or 40.5 mg m^-2 h^-1 in no-tillage area with duck and no-tillage area without duck and conventional-tillage area without duck, respectively. The inhibition of methane emission was apparently effective in the rice-duck ecological system during the initial tillering stage and the full tillering stage. Compared to the no-tillage area without duck, methane emission decreased by 2.333 g m^-2. Compared to the conventional-tillage area without duck, methane emission decreased by 4.723 g m^-2. During the production period of late rice, the amount of methane emission in no-tillage area with duck was 3.373 g m^-2 lesser than that of no-tillage area without duck, and 5.59 g m^-2 less than that of conventional-tillage without duck area. The economic significance was analyzed. Farmers adopting the rice-duck ecological system obtained 2 166 and 4 207 RMB yuan ha^-1 more income than those who adopted a no-tillage without duck technique or conventional-tillage without duck technique, respectively. In addition to the reduction of the environmental pollution by methane emission, the farmers who adopted the rice-duck ecological system achieved economic benefits of 5 000 RMB yuan ha^-1, which was 2 206 and 4 274 RMB yuan ha^-1 more than those who adopted a no-tillage without duck technique and a conventional-tillage without duck technique, respectively. The rice-duck ecological system not only increased the economic benefits for farmers, but also reduced methane emission in rice paddy field. A sustainable agricultural production mode was formed.
基金This research was funded by the Youth Innovation Promotion Association of Chinese Academy of Sciences(1110000002)the Key Project of Chinese Academy of Sciences(QYZDJ-SSWDQC040).
文摘An increasing number of U.S.apple growers are now interested in using harvest platforms to increase harvest productivity,expand labor pool,and alleviate tough working conditions.To maximize benefits,functions of thinning,pruning&training,and infield sorting have been or are to be incorporated into harvest platforms.Though growers are most concerned with economic benefits,few cost-benefit studies had been conducted on different platforms.In the meantime,economic analysis procedure is complex and each analysis is for one specific machine(not for general purposes).No software has been developed as a general and ready-to-use tool for growers and researchers for the platform economic analysis.In this study,platforms,both available on the marketplace and developed in lab as pilot trials,were reviewed.Costs and benefits models were then established,based on which multi-purpose apple harvest platform economic evaluation software(iMPAHP)was developed(capable of evaluating a wide variety of apple harvest platforms).A case study(machine cost of$100000,accommodating 6 workers,processing apple incidence of 10%with 90%sort-out rate,and harvest,thinning,and pruning&training productivity increase by 40%,50%,and 60%,respectively)based on iMPAHP demonstrated that infield sorting,harvest,thinning,and pruning and training accounted for 48.4%,23.9%,14.3%,and 13.4%of the total benefits,respectively.In the case that the platform was in all-four-purpose-application,the net present value(NPV)analysis of a 10-year investment showed a positive return of$60547.However,without infield sorting function,the NPV resulted in a negative value,indicating a loss for the machine investment.Though incorporating the modular infield sorting system certainly increased the overall machine investment by$30000,the benefits outweighed the costs.
文摘A reverse osmosis (RO) desalination system coupled with tidal energy is proposed. The mechanical energy produced by the tidal energy through hydraulic turbine is directly used to drive the RO unit. The system performances and the water cost of the conventional and tidal energy RO systems are compared. It is found that the proposed tidal energy RO system can save water cost in the range of 31.0%-41.7% in comparison with the conventional RO system. There is an optimum feed pressure that leads to the lowest water cost. The tidal RO system can save more costs at a high feed pressure or a high water recovery rate. The optimum feed pressure of the tidal energy RO system is higher than that of the conventional RO system. The longer lifetime of the tidal energy RO system can save even more water cost. When the site development cost rate is lower than 40%, the water cost of the tidal energy RO system will be lower than that of the conventional RO system. The proposed technology will be an effective alternative desalination method in the future.
基金Funding for this project was provided by NRG and COSIA(Canada’s Oil Sands Innovation Alliance)through their sponsorship of the NRG COSIA Carbon XPRIZE.
文摘Scoring the technologies in competition for the NRG Canada’s Oil Sands Innovation Alliance Carbon XPRIZE required an economic evaluation to estimate the value created through the conversion of CO_(2) emissions into products.Across all of the Teams participating in the competition,58 different materials were consumed and produced.Standardized prices and market sizes needed to be established for each of these materials to ensure a consistent evaluation across all Teams.The Standards Data Set(SDS)was created as a standardized database of economic data used in the competition.The rationale for the SDS project and the methodology for researching each material is described.Ultimately,credible material definitions using the SDS methodology were created for all materials,and some research and methodological customization were required for materials that did not have credible,publicly available market data.The methodologies for establishing credible values and market sizes for concrete,concrete admixtures and syngas are highlighted as examples of materials whose value and markets are not easily defined.
文摘This paper describes a new method which is different with the shadow price method to evaluate the economic benefits of the water source project. The approach is to take the water source as a constraint on the regional economic development, calculate the difference between the generaded when the water source project is in operation and the gross product generated when the project is nonexistent, and then review the economic benefits on the project. For this purpose, we have constructed an input-output linear programming model and compiled a compatible using the routines for solving the input-output linear programming model. The above models and the routines have been used in paractical calculation of economic benefits of a water source project for a region. The computation result are satisfactory.
基金supported by State Grid Zhejiang Electric Power Co.,Ltd.(Project of Research on interactive operation control technology and business model of 5G base station energy storage and power grid(B311JX210006)).
文摘Energy storage system is an important means to improve the flexibility and safety of traditional power system,but it has the problem of high cost and unclear value recovery path.In this paper,the typical application scenarios of energy storage system are summarized and analyzed from the perspectives of user side,power grid side and power generation side.Based on the typical application scenarios,the economic benefit assessment framework of energy storage system including value,time and efficiency indicators is proposed.Typical battery energy storage projects are selected for economic benefit calculation according to different scenarios,and key factors are selected for sensitivity analysis.Finally,the key factors affecting economic benefit of the energy storage system are analyzed.
基金supported by the Lingnan Modern Agriculture Project China(NT2021003)the earmarked fund for China Agricultural Research System(CARS-02)。
文摘The invasive fall armyworm Spodoptera frugiperda(J.E.Smith)invaded Asia in 2018,colonizing the tropical and southern subtropical regions as well as migrating with the monsoons into Northeast Asia during spring and summer.This has resulted in widespread infestations,with significant impacts on maize production in various Asian countries.Previous studies have shown that the invasion of this pest can alter the species relationships of maize pests,but the actual impact on maize pest management is still unclear.This study investigated the changes in maize pest occurrence and pesticide use in the annual breeding areas of S.frugiperda in Yunnan Province and the Guangxi Zhuang Autonomous Region of China during 2017-2021,based on surveys and interviews with small farmers in maize production.The results showed that S.frugiperda has emerged as the dominant species among maize pests after invasion and colonization,replacing traditional pests such as Ostrinia furnacalis,Spodoptera litura,Agrotis ypsilon,and Rhopalosiphum maidis.The variety of pesticides used for maize pest control has changed from chlorpyrifos,lambda-cyhalothrin,and acetamiprid to emamectin benzoate-based pesticides with high effectiveness against S.frugiperda.Furthermore,the frequency of maize pest chemical applications has increased from an average of 5.88 to 7.21 times per season,with the amounts of pesticides used in summer and autumn maize being significantly higher than in winter and spring maize,thereby increasing application costs by more than 35%.The results of this study clarified the impact of S.frugiperda invasion on maize pest community succession and chemical pesticide use in tropical and south subtropical China,thereby providing a baseline for modifying the regional control strategies for maize pests after the invasion of this relatively new pest.
基金the China University of Petroleum Foundationthe Research Institute of Safety and Environment TechnologyChina National Petroleum Corporation
文摘This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption (PSA), chemical absorption (CA), and membrane absorption (MA). Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.
基金supported by the National Key Research and Development Program of China(2018YFB0605401)the National Key Research and Development Program Project of Ningxia(2018BEE03009)+1 种基金the National Natural Science Foundation of China(21868025)Major Program of Key Research and Development Program of Ningxia Province of China(2018BCE01002).
文摘In this work,a model of hydrogen production by double chemical looping is introduced.The efficiency benefit obtained was investigated.The chemical looping hydrogen generation unit is connected in series to the downstream of a chemical looping gasification unit as an additional system for 100 MWh coal gasification,with the function of supplementary combustion to produce hydrogen.Using Aspen Plus software for process simulation,the production of H_(2) and N_(2) in the series system is higher than that in the independent Chemical looping gasification and Chemical looping hydrogen generation systems,and the production of hydrogen is approximately 25.63%and 12.90%higher,respectively;The study found that when the gasification temperature is 900C,steam-carbon ratio is 0.84 and oxygen-carbon ratio is 1.5,the hydrogen production rate of the system was the maximum.At the same time,through heat exchange between logistics,high-pressure steam at 8.010×10^(4) kg·h^(-1) and medium-pressure steam at 1.101×10^(4) kg·h^(-1) are generated,and utility consumption is reduced by 61.58%,with utility costs decreasing by 48.69%.An economic estimation study found that the production cost of ammonia is 108.66 USD(t NH_(3))^(-1).Finally,cost of equipment is the main factors influencing ammonia production cost were proposed by sensitivity analysis.
文摘LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incremental and sensitivity analysis to determine whether it is feasible to incorporate current battery technology into these machines. When revenue was taken into account, decreasing the amount of haulage in battery operated equipment by 5% or 200 kg per h amounts to a $4.0 × 10~4 loss of profit per year. On average it was found that using battery operated equipment generated $9.5 × 10~4 more in income annually, reducing the payback period from seven to two years to pay back the additional $1.0 × 10~5 investment of buying battery powered equipment over cheaper diesel equipment. Due to the estimated 5% increase in capital, it was observed that electric vehicles must possess a lifetime that is a minimum of one year longer than that of diesel equipment.
基金funding by the National Natural Science Foundation of China(No.51978643)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21021102)+2 种基金14th Five-year Informatization Plan of Chinese Academy of Sciences,Construction of Scientific Data Center System(WX145XQ07-12)Youth Innovation Promotion Association,CAS(Y201814)the National Youth Talent Support Program of China
文摘The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements.The traditional measures substantially increased the related costs for enterprises to reach standards.This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems.Typical three coking wastewater treatment processes in China were evaluated.Results showed that eutrophication dominantly contributed to the overall environmental effect.Improving effluent quality could significantly reduce the total environmental impact.In terms of an economic perspective,the price of raw materials was the main factor that affected the operating cost of comprehensive treatment.Based on subsystem analysis,the pretreatment stage accounted for the majority of environmental and cost burdens,respectively reaching 64%-78%and 64%-86%.Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8%and 57%,respectively,which was an effective way to improve the potential performance of coking wastewater treatment plants(WWTPs).
文摘Objective To systematically review the published clinical and economic research on liposomal irinotecan in combination with 5-FU/LV for metastatic pancreatic ductal adenocarcinoma(mPDAC)at home and abroad.Methods PubMed,Cochrane Library,Embase,CBM,CNKI,Wan Fang data,CRD database and health technology assessment official websites were searched to collect clinical and economic studies on liposomal irinotecan for mPDAC.Results and Conclusion Nine clinical studies and four economic studies were included.The result of clinical studies showed that liposomal irinotecan in combination with 5-FU/LV could extend survival with good drug compliance in patients with mPDAC who progressed on prior gemcitabine-based therapy.This agent represented a new treatment option for second-line chemotherapy in these patients.The results of the economic evaluations failed to reach a consistent conclusion due to different economic levels in various countries.
文摘目的对经外周置入中心静脉导管(peripherally inserted central catheter,PICC)置管、维护及拔管的单项操作成本进行核算,为制定合理的操作收费价格提供依据。方法通过横断面调查,采用项目成本阶梯分摊法,于2019年1—5月在复旦大学附属肿瘤医院血管通路门诊测算PICC各单项操作人力成本、设备折旧费及未单独计价材料费,测算直接成本,并通过分摊测算间接成本,最后测算PICC置管、维护及拔管的单项操作成本。结果PICC置管、维护及拔管的各单项操作实际成本分别为(157.03±4.73)元、(33.66±3.04)元、(32.38±3.11)元,与上海市医疗机构对PICC各项操作的收费标准(分别为150元、30元、30元)基本相符。结论建议将PICC维护及拔管的操作收费纳入收费标准中,促进PICC输液技术的可持续发展并确保护理服务的持续供给。