Multi-objective optimization design of deviation-correction trajectory considering the production loss in shale gas cluster well

In shale gas mining,the inter-fracture interference effect will significantly occur if the actual well deviates from the planned trajectory.To reduce production loss,operators want to get back on the planned trajectory economically and safely.Based on this,a multi-objective optimization model of deviationcorrection trajectory is established considering the production loss evaluation.Firstly,the functional relationship between the production envelope and the fracturing depth is constructed,and the production loss is obtained by combining the calculation method of volume flow.Based on the proposed“double-arc”trajectory design method,the production loss of the fracture on the deviation-correction trajectory is obtained.Finally,combined with the well profile energy evaluation,a new optimization model of deviation-correction trajectory is established.The results demonstrate that after optimizing the fracturing depth,the production loss of the deviation-correction trajectory is reduced by 13.2%.The maximum curvature value results in a trajectory with a minimum production loss yet a maximum well profile energy.The proposed model reduces the well profile energy by 15.6%compared with the existing model.It is proved that the proposed model can reduce the probability of drilling accidents and achieve high gas production in the later mining stage.This study fully considers various factors affecting horizontal wells in the fracturing area,which can provide theoretical guidance for the design of deviationcorrection trajectory.

Investigation of Pile Construction and Productivity Loss: An Analysis of Macro Impact Factor

Pile foundations are challenging to build due to subsurface obstacles, contractor ignorance, and difficulties with site planning. Given the unpredictable environment of the construction site, productivity losses during pile work are to be thought possible. Prior to finishing a site pre-investigation, a foundation’s area is usually sampled for statistical reasons. There are studies on pile construction outside of Bangladesh that are supported by relevant empirical data in the literature. Since Bangladesh, which is regarded as a third-world country, is ignored in this regard, the literature currently available about pile building and the associated productivity loss is unable to provide adequate information or appropriate empirical data. Due to this pile-building sector in Bangladesh has been experiencing a decline in production for quite some time now. Before attempting to increase productivity in pile construction, it is essential to investigate the potential losses and the variables that might have an influence. This study aims to accomplish the following objectives: 1) identify the primary factors that have an impact on pile construction;2) develop an SVR model that accurately predicts productivity loss;and 3) figure out the projected loss by basing it on the historical scenario that is the most comparable to the current one. A Support Vector Regression (SVR) model was developed after a study of the relevant literature. This model enabled the collection of 110 pile building projects from five significant locations in Bangladesh. The model was constructed using a list of eight inputs in addition to a list of five macro elements (labor, management, environment, material, and equipment) (soil condition, pile type, pile material, project size, project location, pile depth, pile quantity, and equipment quantity). Using 10-way cross validation, the SVR achieves an accuracy of 87.2% in its predictions. On the basis of what has occurred in the past, we are able to estimate that there will be a loss of around 18.55 percent of the total output. A new perspective for engineers studying the delay factors with productivity loss is provided by the outcome of important tasks as it relates to loss in productivity and overall factors faced. In the building construction industry, effective management should place more emphasis on the correlation between productivity loss and the factors that cause it. Therefore, to represent the effect on productivity loss, real factors can be summed up as a decline in productivity loss. The findings of the study would urge specialists to concentrate on waste as a means of increasing overall production.

Relation between oxidation microstructure and the maximum energy product loss of a Sm_2Co_(17) magnet oxidized at 500℃

The oxidation microstructure and maximum energy product （BH）max loss of a 8m（Co0.76, Fe0.1, Cu0.1, Zr0.04）7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet： a continuous externM oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature （BH）max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of （BH）max loss on oxidation time. It is found that the external oxide scale has little effect on the （BH）max loss, and both the internal reaction layer and diffusion zone result in the （BH）max loss. Moreover, the diffusion zone leads to more （BH）max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91×10^-10 cm^2/s and 6.54×10^-11 cm^2/s, respectively.

Entropy Production Analysis for Hump Characteristics of a Pump Turbine Model

The hump characteristic is one of the main problems for the stable operation of pump turbines in pump mode.However,traditional methods cannot reflect directly the energy dissipation in the hump region.In this paper,3D simulations are carried out using the SST k-ω turbulence model in pump mode under different guide vane openings.The numerical results agree with the experimental data.The entropy production theory is introduced to determine the flow losses in the whole passage,based on the numerical simulation.The variation of entropy production under different guide vane openings is presented.The results show that entropy production appears to be a wave,with peaks under different guide vane openings,which correspond to wave troughs in the external characteristic curves.Entropy production mainly happens in the runner,guide vanes and stay vanes for a pump turbine in pump mode.Finally,entropy production rate distribution in the runner,guide vanes and stay vanes is analyzed for four points under the 18 mm guide vane opening in the hump region.The analysis indicates that the losses of the runner and guide vanes lead to hump characteristics.In addition,the losses mainly occur in the runner inlet near the band and on the suction surface of the blades.In the guide vanes and stay vanes,the losses come from pressure surface of the guide vanes and the wake effects of the vanes.A new insight-entropy production analysis is carried out in this paper in order to find the causes of hump characteristics in a pump turbine,and it could provide some basic theoretical guidance for the loss analysis of hydraulic machinery.

Occupational Heat Stress in the Floriculture Industry of Ethiopia: Health Risks and Productivity Losses

Background: The Ethiopian flower industry is growing fast with successful diversification of export products under greenhouse structures. Higher temperatures in the greenhouses pose a serious threat to the health of workers and add to the risk of occupational heat stress. Excessive heat in workplace settings also reduces work capacity and labour productivity. This study aims to investigate the level of heat exposure, and workers’ and managers’ perceptions and behavioural responses towards extreme heat exposure in a warming climate. Methods: We used the Wet Bulb Globe Temperature (WBGT) measured in representative greenhouses to capture the heat exposure during hotter and cooler seasons following ISO 7243 (generally risk of heat stress occurs when WBGT exceeds 26°C). A comparative cross-sectional study design with a stratified sampling method was used to assess occupational heat stress and workers’ perceptions of the impact of heat on their health and productivity in six different floriculture greenhouses in Ethiopia representing three different agro-ecologies and products. A questionnaire survey was conducted (30 managers/supervisors and 305 workers;76.1% female) to capture perceptions on heat exposures, symptoms of potential health impacts, productivity losses and coping mechanisms. Results: Heat exposure varied across different agroecologies, product types and greenhouse materials with a median WBGT Index of 25.5°C and a range from 18.1°C to 31.5°C. The impact of heat stress also varied across different employment sectors and geographical regions. Overall, workers in cut-flower greenhouses are exposed to higher than recommended WBGT Index (26°C) for 3 - 6 working hours daily. 65% of the managers reported that heat stress has a significant impact on the workers’ labour productivity, but do not have guidance about working in hot conditions. Workers reported more heat-related health issues and reduced productivity, especially in the mid-altitude greenhouses. About 50% of the workers reported that heat exposure decreased work productivity during hot hours. Sweating, exhaustion, heat-rashes, dehydration, crumps, nausea and headache were self-reported health issues. Labour productivity losses ranged from no loss to 19.5% in the mid- and low-altitudes. Conclusions and Recommendations: Excessive workplace heat in the greenhouses is both an occupational health hazard and detrimental to productivity in the floriculture industry. However, the level of understanding and actions on the ground regarding occupational heat stress are low. The code of conduct in place now does not consider the occupational heat stress issues. Multiple actions (engineering, management, training and policy-related recommendations) have to be implemented by Ethiopian Horticultural Producers and Exporters Association (EHPEA) and farm owners to mitigate heat stress and loss of productivity. Designing and implementing these heat prevention strategies and incorporating them into the code of conduct is in the interests of both employers and employees.

生产率损失测量工具的比较研究

目的 比较可用于卫生技术评估中的生产率损失测量工具,厘清可用于卫生技术评估中的生产率损失测量工具的应用条件,以期为相关研究者在选择生产率损失的测量工具时提供参考。方法 检索PubMed、Web of Science、中国知网、万方、维普等中外数据库,检索时间从数据库建库至2021年11月,由2名研究者按照纳入与排除标准独立筛选文献、识别生产率损失测量工具、提取资料。结果 共识别出5种可用于卫生技术评估领域中的生产率损失测量工具,包括工作能力和活动受损量表(work productivity activity and impairment,WPAI)、工作能力局限调查问卷(work limitations questionnaire,WLQ)、健康与工作绩效问卷(Health and Work Performance Questionnaire,HPQ)、损失产能的估值(Valuation of Lost Productivity Questionnaire,VOLP)和医疗技术评估研究院(Institute for Medical Technology Assessment,IMTA)的生产力成本问卷(IMTA Productivity Questionnaire,IPCQ)。其中WPAI和WLQ是测量属性证据最为充足的工具;VOLP是成本涵盖最全的工具;WLQ是数据敏感性最强的工具;IPCQ是货币转化方法最多的工具;WPAI是获取使用最方便的工具。结论 对于卫生技术评估中的生产率损失测量的标准工具尚未存在统一共识,研究者可根据自身研究选取生产率损失测量工具。

Economic burden of irritable bowel syndrome in China

AIM To estimate annual direct and indirect costs for patients diagnosed with irritable bowel syndrome(IBS) and subtypes.METHODS Patients completed a standardized questionnaire concerning usage of healthcare resources, travel costs, meals, and productivity loss of patients when seeking treatment for IBS. Total annual costs per patient were calculated as the sum of direct(including medical and nonmedical) and indirect costs. Total annual costs per patient among various IBS subtypes were compared. Analysis of variance and bootstrapped independent sample t-tests were performed to determine differences between groups after controlling for IBS subtypes.RESULTS A total of 105 IBS patients(64.80% female), mean age of 57.12 years ± 10.31 years), mean disease duration of 4.31 years ± 5.40 years, were included. Total annual costs per patient were estimated as CNy18262.84(USD2933.08). Inpatient and outpatient healthcare use were major cost drivers, accounting for 46.41%and 23.36% of total annual costs, respectively. Productivity loss accounted for 25.32% of total annual costs. The proportions of direct and indirect costs were similarto published studies in other countries. Nationally, the total costs of managing IBS would amount to CNy123.83 billion(USD1.99 billion). Among the IBS subtypes, total annual costs per patient of IBS-M was highest at CNy18891.18(USD3034). Furthermore, there was significant difference in productivity loss among IBS subtypes(P = 0.031).CONCLUSION IBS imposes a huge economic burden on patients and healthcare systems, which could account for 3.3% of the total healthcare budget for the entire Chinese nation. More than two-thirds of total annual costs of IBS consist of inpatient and outpatient healthcare use. Among the subtypes, IBS-M patients appear to have the greatest economic burden but require further confirmation.

MEASUREMENTS AND MODEL SIMULATIONS OF SURFACE OZONE VARIATIONS AT DIFFERENT BACKGROUND CONCENTRATIONS OF THE PRECURSORS

Ozone photochemical production and loss in very different environments at Waliguan baseline station and Lin'an background station were simulated by using the measurement data and photo- chemical box model.The results show that net ozone photochemical production rate is negative, about 0.5 ppb/d,at Waliguan baseline sation,because of very low precursor concentrations.But at Lin'an background station,the net photochemical ozone production is positive,about 2—3 ppb/ h.which is very closed with the measurement at Lin'an.That means ozone production was con- trolled by photochemical reactions at Lin'an background station,because of the higher precursor concentrations.The net destruction rate,at Waliguan Mt.,is not large,so that future increase in anthropogenic emission of reactive nitrogen will lead to larger production rates of steady-state O_3 concentration.

The monetary value of human lives lost due to neglected tropical diseases in Africa

Background:Neglected tropical diseases(NTDs)are an important cause of death and disability in Africa.This study estimates the monetary value of human lives lost due to NTDs in the continent in 2015.Methods:The lost output or human capital approach was used to evaluate the years of life lost due to premature deaths from NTDs among 10 high/upper-middle-income(Group 1),17 middle-income(Group 2)and 27 low-income(Group 3)countries in Africa.The future losses were discounted to their present values at a 3%discount rate.The model was re-analysed using 5%and 10%discount rates to assess the impact on the estimated total value of human lives lost.Results:The estimated value of 67860 human lives lost in 2015 due to NTDs was Int$5112472607.Out of that,14.6%was borne by Group 1,57.7%by Group 2 and 27.7%by Group 3 countries.The mean value of human life lost per NTD death was Int$231278,Int$109771 and Int$37489 for Group 1,Group 2 and Group 3 countries,respectively.The estimated value of human lives lost in 2015 due to NTDs was equivalent to 0.1%of the cumulative gross domestic product of the 53 continental African countries.Conclusions:Even though NTDs are not a major cause of death,they impact negatively on the productivity of those affected throughout their life-course.Thus,the case for investing in NTDs control should also be influenced by the value of NTD morbidity,availability of effective donated medicines,human rights arguments,and need to achieve the NTD-related target 3.3 of the United Nations Sustainable Development Goal 3(on health)by 2030.