Influencing factors and prevention measures of casing deformation in deep shale gas wells in Luzhou block,southern Sichuan Basin,SW China

Based on structural distribution and fault characteristics of the Luzhou block,southern Sichuan Basin,as well as microseismic,well logging and in-situ stress data,the casing deformation behaviors of deep shale gas wells are summarized,and the casing deformation mechanism and influencing factors are identified.Then,the risk assessment chart of casing deformation is plotted,and the measures for preventing and controlling casing deformation are proposed.Fracturing-activated fault slip is a main factor causing the casing deformation in deep shale gas wells in the Luzhou block.In the working area,the approximate fracture angle is primarily 10°-50°,accounting for 65.34%,and the critical pore pressure increment for fault-activation is 6.05-9.71 MPa.The casing deformation caused by geological factors can be prevented/controlled by avoiding the faults at risk and deploying wells in areas with low value of stress factor.The casing deformation caused by engineering factors can be prevented/controlled by:(1)keeping wells avoid faults with risks of activation and slippage,or deploying wells in areas far from the faulting center if such avoidance is impossible;(2)optimizing the wellbore parameters,for example,adjusting the wellbore orientation to reduce the shear force on casing to a certain extent and thus mitigate the casing deformation;(3)optimizing the casing program to ensure that the curvature radius of the curved section of horizontal well is greater than 200 m while the drilling rate of high-quality reservoirs is not impaired;(4)optimizing the fracturing parameters,for example,increasing the evasive distance,lowering the single-operation pressure,and increasing the stage length,which can help effectively reduce the risk of casing deformation.

Occurrence Characteristics and Prevention and Control Measures of Spodoptera frugiperda in Maize

Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and control,agricultural prevention and control,physical prevention and control,chemical prevention and control,and biological prevention and control can effectively control the damage of S.frugiperda and guarantee the safety of food production.The results will provide some reference for the prevention and control of S.frugiperda.

Characteristics of coal resources in China and statistical analysis and preventive measures for coal mine accidents

In the process of green and smart mine construction under the context of carbon neutrality,China's coal safety situation has been continuously improved in recent years.In order to recognize the development of coal production in China and prepare for future monitoring and prevention of safety incidents,this study mainly elaborated on the basic situation of coal resources and national mining accidents over the past five years(2017-2021),from four dimensions(accident level,type,region,and time),and then proposed the preventive measures based on accident statistical laws.The results show that the storage of coal resources has obvious geographic characteristics,mainly concentrated in the Midwest,with coal resources in Shanxi and Shaanxi accounting for about 49.4%.The proportion of coal consumption has dropped from 70.2%to 56%between 2011 and 2021,but still accounts for more than half of the all.Meanwhile,the accident-prone areas are positively correlated with the amount of coal production.Among different levels of coal mine accidents,general accidents had the highest number of accidents and deaths,with 692 accidents and 783 deaths,accounting for 87.6%and 54.64%respectively.The frequency of roof,gas,and transportation accidents is relatively high,and the number of single fatalities caused by gas accidents is the largest,about 4.18.In terms of geographical distribution of accidents,the safety situation in Shanxi Province is the most severe.From the time distribution of coal mine accidents,the accidents mainly occurred in July and August,and rarely occurred in February and December.Finally,the"4+4"safety management model is proposed,combining the statistical results with coal production in China.Based on the existing health and safety management systems,the manage-ments are divided into four sub-categories,and more specific measures are suggested.

Study on the Safety and Prevention Technology of Coal Mining under the River in Xingyuan Coal Mine

Coal mining-induced surface subsidence poses significant ecological and infrastructural challenges, necessitating a comprehensive study to ensure safe mining practices, particularly in underwater conditions. This project aims to address the extensive impact of coal mining on the environment, infrastructure, and overall safety, focusing on the Shigong River area above the working face. The study employs qualitative and quantitative analyses, along with on-site engineering measurements, to gather data on crucial parameters such as coal seam characteristics, roof rock lithology, thickness, water resistance, and structural damage degree. The research encompasses a multidisciplinary approach, involving mining, geology, hydrogeology, geophysical exploration, rock mechanics, mine surveying, and computational mathematics. The importance of effective safety measures and prevention techniques is emphasized, laying the foundation for research focused on the Xingyun coal mine. The brief concludes by highlighting the potential economic and social benefits of this project and its contribution to valuable experience for future subsea coal mining.

Adherence to Preventive Measures during the COVID-19 Pandemic among University Students in Sudan

Background: Coronavirus disease 2019, otherwise known as COVID-19, emerged in December of 2019. COVID-19 spreads through an airborne transmission route. Preventive measures were described to help decrease the spread of COVID-19 worldwide. There were a number of preventive measures that were globally adopted: social distance of at least 1 meter, mask wearing, washing hands for 20 seconds, and covering the mouth and nose if the person sneezes or coughs. Methods: A descriptive cross-sectional study among 362 students from the International University of Africa, Sudan, was carried out between August 2021 and September 2022. Statistical Package for Social Sciences version 26 was used for data analysis;frequency and percentage were used to describe the qualitative variables. A chi-square test was used for association analysis;a P-value ≤ 0.05 was considered statistically significant. Results: Among study participants, the females were 70.9%;most were 20 - 23 years old (73.6%). 54.2% were vaccinated against COVID-19;83.6% had good knowledge regarding the mode of transmission, and 76.1% stayed in during quarantine. 80.6% of participants understood social distancing correctly. 76.1% of males and 45.1% of females started or completed vaccination (P ≤ 0.05). 51.4% of males and 81.3% of females adhered to preventive measures (P ≤ 0.05). Conclusions: It is important to target health education campaigns and interventions to improve adherence to preventive measures among university students. Although the pandemic is coming to an end, a lesson should be learned from it, and future preparation should be employed.

Mechanisms of support failure and prevention measures under double-layer room mining gobs——A case study: Shigetai coal mine

In the practice of mining shallow buried ultra-close seams,support failure tends to occur during the process of longwall undermining beneath two layers of room mining goaf(TLRMG).In this paper,the factors causing support failure are summarized into geology and mining technology.Combining column lithology and composite beam theory,the key stratum of the rock strata is determined.A finite element numerical simulation is used to analyze the overlying load distribution rule of the main roof for different plane positions of the upper and lower room mining pillars.The tributary area theory(TAT)is adopted to analyze the vertical load distribution of each pillar,and dynamic models of coal pillar instability and main roof fracture are established.Through key block instability analysis,two critical moments are established,of which critical moment A has the greater dynamic load strength.Great economic losses and safety hazards are created by the dynamic load of the fracturing of the main roof.To reduce these negative effects,a method of pulling out supports is developed and two alternative measures for support failure prevention are proposed:reinforcing stope supports in conjunction with reducing mining height,or drilling ground holes to pre-split the main roof.Based on a comprehensive consideration of economic factors and the two categories of support failure causes,the method of reinforcing stope supports while reducing mining height was selected for use on the mining site.

Assessment on the Effects of Hepatitis B Prevention and Control Measures in Western China:A Comparison of Three Population-based Serosurveys

Objective Despite the remarkable progress in efforts to control disease spread,the nationwide elimination of hepatitis B in China is still hindered by the persistently high rate of hepatitis B virus(HBV)infection in Western China.This study aimed to evaluate the strategy of hepatitis B prevention and control in Western China and identify potential areas and strategies for improvement.Methods Susceptible population vaccination,health education,professional training of doctors,and other prevention and control measures have been implemented in Wuwei city since 2010.Data were obtained from three representative cross-sectional serosurveys conducted in 2010,2013,and 2015.The serum samples were subjected to enzyme-linked immunosorbent assays to detect the following seromarkers:HBV surface antigen(HBsAg),antibody against hepatitis B surface antigen(anti-HBs),and antibody against hepatitis B core antigen(anti-HBc).Estimates of variance were determined using Taylor series linearization methods.Results The three serosurveys revealed decreases in the prevalence of HBsAg(7.19% in 2010 vs.6.51% in 2013 vs.5.87% in 2015)and anti-HBc positivity(43.89%vs.32.87%vs.28.46%)and an increase in the prevalence of anti-HBs positivity(49.07%vs.53.66%vs.53.72%)over time.From 2010 to 2015,the legally reported incidence of hepatitis B in Wuwei city decreased from 686.53/100,000 to 53.72/100,000.Notably,persistently high HBsAg-positive rates(above 5.40%)were observed among subjects aged 20–69 years old in the three serosurveys;the prevalence of HBsAg was above 1% among children younger than 10 years old.Furthermore,rural subjects had higher rates of HBsAg and anti-HBc positivity than their urban counterparts(6.04%vs.4.83% and 30.26%vs.20.35%,respectively)in 2015 but had a lower rate of anti-HBs positivity(49.68 vs.55.18%).Multivariate regression analysis showed that age,urban and rural areas,and education level were the main factors affecting HBV infection.Conclusion Although vaccine-based prevention and control measures reduced the rate of HBV infection in Wuwei City over time,the hepatitis B infection rate in children younger than 10 years was still higher than the national average level.Therefore,the prevention and control of mother-to-child transmission and the management of the infected should be the focus of future prevention and control work.

Causes of Recurrence of Rice Chilo suppressalis( Walker) in Longyou County and Prevention and Control Measures

In recent years,the occurrence of rice Chilo suppressalis( Walker) in Longyou County of Zhejiang Province has increased year by year and has become aggravated. This poses a great threat to the safety of rice production. In order to curb the recurrence momentum of rice C. suppressalis,according to the dynamic monitoring and field system survey of rice C. suppressalis in Longyou County since 2015,the causes of the annual increase of rice C. suppressalis in recent years were analyzed,and the recurrence area of C. suppressalis was introduced,and finally some prevention and control measures were put forward.

Prevention and Control Measures of Environmental Pollution Problem Caused by Dairy Farming in Inner Mongolia

Environmental pollution problem generated in dairy farming process is the bottleneck restricting development of animal husbandry. By using the investigation data from dairy farmers of Inner Mongolia,environmental pollution problem generated by dairy farming in Inner Mongolia and its cause were analyzed,and prevention and control measures were put forward. The research result showed that weak technology support of environmental treatment and environmental-protection awareness of dairy farmer and bad application effect of pollution control technology caused by lower education degree of dairy farmer were main reasons for environmental pollution problem. We should develop dairy circular economy,advocate a moderate scale,scientifically breed,and enhance training of pollution control technology and propaganda to protect environment.

Optimization Study of Outburst Prevention Measures for Tuzhu Coal Mine Based on Fixed Weight Clustering Analysis

Affected by many involved factors, different dimensions, data with large difference, incomplete information and so on, the most optimal selection of regional outburst prevention measures for outburst mine has become a complicated system project. The traditional way of outburst prevention measure selection belongs to qualitative method, which may cause high-cost of gas control, huge quantities of drilling work, long construction time and even secondary disaster. To solve the above-mentioned problems, in light of occurrence status of coal seam gas in No. 21 mining area of Jinzhushan Tuzhu Mine, through grey fixed weight clustering theory and a combination method of qualitative and quantitative analysis, the judging model with multi-objective classification for optimization of outburst prevention measures was established. The three weight coefficients of outburst prevention technology scheme are sorted, in order to determine the advantages and disadvantages of each outburst prevention technology scheme under the comprehensive evaluation of multi-target. Finally, the problem of quantitative selection for regional outburst prevention technology scheme is solved under the situation of multi-factor mode and incomplete information, which provides reasonable and effective technical measures for prevention of coal and gas outburst disaster.

Research Progress and Prospect on Prevention and Control Measures of Sweet Potato Virus Disease

Sweet potato virus disease is a serious biological threat to sweet potato,which seriously affects the development of sweet potato industry in China.This paper gives a brief introduction to the main defensive measures of sweet potato virus disease,such as cutting of virus infection source,killing of viral transmission media,cultivation and application of virus-free sweet potato,use of antiviral agents,breeding of varieties with virus resistance,and mild strain cross protection,so as to provide some reference for this field.

Scenario of Infection Prevention and Control Measures for Tuberculosis in Tuberculosis Inpatient and Outpatient Department in Tertiary Care Hospital

Tuberculosis is one of the most important infectious diseases in our country. Also nosocomial infection by tuberculosis can occur, which can be prevented by implementing simple, effective and affordable tuberculosis infection control measures in health care facilities. To evaluate the effectiveness of infection control measures, such study was planned. Questionnaires were administered to all doctors, healthcare workers and servants working in outdoor and indoor department of tuberculosis at tertiary care hospital to assess the knowledge, attitudes and practices on prevention and control of Tuberculosis infection. A scoring system was devised to grade them. One-time audit was also done in outpatient and inpatient department. The analysis showed scoring of poor for doctors, good for nurses and poor forward aids. There is a need to develop strategies for training of health care workers on regular basis in order to reduce the incidence of nosocomial infections. Audit result shows a good level of environmental control measures. Better knowledge, attitude and practices are helpful for the prevention and control of tuberculosis. Also environmental control measures are helpful to prevent infection.

Prevention and Control Measures of Bovine Viral Diarrhea Virus in Developed Country and Its Inspiration to China

Bovine viral diarrhea disease is an important disease in the world, which causes great economic loss and leads to serious clinical symptoms such as drop in milk and meat production, reproductive failure, growth retardation, and secondary infection increasing the mortality rate. The developed countries have made a series of measures in preventing the disease and made a great purpose. This paper summarizes those methods in order to make a reference for the control of the disease in China.

The Prevention and Control Measures of COVID-19 in the People’s Hospital of Pingchang County

COVID-19 (COVID-19) or COVID-19 is pneumonia caused by the novel coronavirus infection in patients in 2019. COVID-19 pneumonia epidemic is widespread, wide, and deep. To effectively combat the further spread of COVID-19: the overall protocol of the hospital: “three lines of defense” of community prevention and control, fever clinic and face-to-face treatment;grasp the good three-time limits: “2 hours, 12 hours and 24 hours”;do a good job of three key points: key areas and places and groups;carry out four early prevention and control measures: early detection, early reporting, early isolation and early treatment;management of confirmed, suspected, fever, close contact “four types of personnel”;implement l responsibility system;doing all receivable, should be treated, should be checked, should be separated by “four should be”;do investigation, control, supervision, education, and care “five in place”. Through the above methods, the People’s Hospital of Pingchang County has effectively controlled COVID-19.

Major hazard sources analysis and prevention measures of packaging emulsion explosive production line

Emulsion explosive with favorable water-resistance performance,storage performance and detonation stability has been widely used in all over the world.The development actuality and production technique characteristics of emulsion explosive in China were introduced firstly.Taken the technique characteristics of packaging emulsion explosive into account,major hazard sources of emulsion explosive production line were analyzed.Finally,prevention measures based on inherent safety of emulsion explosive production were put forward.

Prevention and Control Measures of the Occurrence of Ceracris kiangsu Tsai in Sugarcane Areas of Yunnan Province

Ceracris kiangsu Tsai is one of the most widely distributed forest pest.C.kiangsu has migrated from Laos to China this year,with many migration peaks and large population numbers.The main sources of C.kiangsu were from abroad and a small number of native insect sources exist.Most of the immigration sources were from Laos,and a small part originated from Vietnam.The frontier region of Yunnan Province is suitable for the growth of C.kiangsu.It is speculated that the migration frequency of the C.kiangsu from abroad may increase in recent years.In this paper,the typical morphological characteristics,life history,biological characteristics and prevention and control measures of C.kiangsu were summarized.Based on the characteristics of C.kiangsu,and combining actual sugarcane production condition in Yunnan sugarcane areas,we put forward prevention and control strategies and measures.It is suggested that Yunnan Sugarcane areas should pay close attention to the occurrence of C.kiangsu in neighboring countries,monitor the C.kiangsu population dynamics and update pest forecast information in time,and detect and control C.kiangsu in the early period,in order to effectively prevent C.kiangsu and ensure the safety of sugarcane production.

Cause and Prevention Measures of Concrete Cracks during the Construction of Road and Bridge Engineering

Road and bridge engineering is an indispensable part of socialist economic construction in China, whose construction quality significantly affects the infrastructure construction level in the whole society. To meet the rapid economic development of various regions, construction scale and quantity of road and bridge engineering have been continuously expanded and increased, therefore, higher requirements for construction quality and construction standard are also presented. During the construction of road and bridge engineering, concrete crack is a key problem which affects the construction quality. In this regard, this paper analyzes cause and prevention measures of concrete cracks during the construction of road and bridge engineering, and hopes to provide construction personnel with valuable references.

The Principle of Proportionality Toward Risk Prevention——Based on the Judgment Logic of European COVID-19 Derogation Measures

The COVID-19 pandemic has brought legal challenges to the containment measures adopted by European countries.During the outbreak and containment phase of the pandemic,most European countries adopted measures such as lockdowns and mandatory home quarantines based on the principle of risk prevention.However,Article 15 of the European Convention on Human Rights and judgments by the European Court of Human Rights require such measures to comply with the principle of proportionality.In view of this,this article examines the European Court of Justice’s loose judgments on the derogation measures during the pandemic,and the European Court of Human Rights’situational judgments in this regard.Based on the analysis of the legitimacy of the principle of risk prevention and the principle of proportionality in responding to public health emergencies,this article prudently examines and predicts the trend of applying the principle of proportionality of risk prevention for the European COVID-19 derogation measures from three perspectives of legitimacy,necessity,and feasibility.

Study on the Status Quo and Prevention-control Measures of Seawater Intrusion in Qingdao City

Firstly, the general situation, influencing factors and damage of seawater intrusion in Qingdao City, Shandong Province were analyzed, and then some appropriate remedial measures were put forward, such as improving groundwater monitoring system in costal areas, exploiting groundwater reasonably, building underground cut-off walls and strengthening river management, which would provide a new approach for the prevention and control of seawater intrusion in Qingdao City.

Risk assessment and landslide prevention design using numerical modelling——A case study in Qingliu,China

Numerous Quaternary deposits are existed in the mountainous areas of Southwest China,especially in the transition zone between the QinghaiTibet Plateau and the Sichuan Basin,where strong tectonic movements and frequent climatic changes increase the potential landslides.The possible deformation and failure process of potential landslides and their impacts on the surrounding environment are important research topics.Field investigation and monitoring indicate that the Qingliu landslide in Xiameng town,Li County,Sichuan Province,China has been continuously deforming since August 2020.The deformation zone has a maximum deformation depth of approximately 18.9m,a total area of 54,628 m2,and a volume of 34.0×104 m3,which seriously threatens infrastructure projects and dwellings.As a result,understanding the Qingliu landslide evolution process,assessing the hazard risk,and planning disaster prevention measures are of great significance for reducing disaster loss.In this study,the mass movement process and hazard risk of the Qingliu landslide are evaluated,and the effects of different prevention measures are compared and discussed.By using the depth-integrated method,the mass movement of the Qingliu landslide is analyzed.The numerical simulation results indicate that the maximum velocity of the Qingliu landslide is approximately 37.5 m/s,and the duration of the landslide is approximately 90s.The simulated landslide can eventually form a deposited mass with a maximum deposit thickness of 19.4 m and an area of approximately 60,168.3 m2,thereby blocking the river and burying dwellings.Furthermore,a risk assessment of the Qingliu landslide under different forms of protection measures is also produced and discussed by considering the hazard level and economic vulnerability level of the affected area.Setting three layers of anti-slide piles on the deformation zone to reduce the hazard risk of the Qingliu landslide is a better choice.Our results may be useful for planning prevention measures and improving disaster emergency response systems.