scholarly journals Analysis on the Difference of Energy Evolution in the Process of Energy Storage Failure of Strong Coal Rush Rock Samples under Different Adaptive Modification Regulation Measures

2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Fangfang Zhang
Keyword(s):  
Prevention And Control ◽  
Strain Energy ◽  
Water Injection ◽  
Control Measures ◽  
Energy Regulation ◽  
Energy Evolution ◽  
Pressure Relief ◽  
Rock Samples ◽  
Ground Pressure ◽  
And Control

Current energy to “release” after accumulating + first for the mechanism of rock bursts occurred in analysis of the strategy is accepted by many scholars, based on the existing means of prevention and control of percussive ground pressure, from the angle of the prevention and control of design of the mechanism of impact ground pressure energy regulation, namely, “weakened after the first release +” softened water injection measures and “lead after the first release +” drilling pressure relief measures, for the study of mining under the action of a strong shock tendentiousness rock energy regulatory mechanism; based on rock mechanics experiment, the analysis under different modification measures should be variant energy storage mechanisms of induced damage evolution of rock energy. The mechanism of energy evolution in the modification of strong bursting liability roof rock is revealed. The results show that different modification regulation measures can effectively change the physical and mechanical parameters of target rock samples and realize “hard rock softening or soft rock hardening.” Samples under different modification measures are classified as initial consolidation stage, elastic stage, stage of plastic deformation, yield failure stage, and late stage, the energy evolution is roughly the same as the sample complete natural condition, but the yield failure stage and the destruction of late stage have an obvious difference, which provides favorable conditions for impact ground pressure to prevent. With the help of three characteristic energy indexes of total strain, elastic strain energy, and dissipative strain energy of rock samples, the evolution law of energy indexes under different modification control measures is analyzed. The index of elastic energy consumption ratio is introduced as a precursor feature of rock instability and failure, which indicates the rock impact tendency to a certain extent. The energy regulation mechanisms of “first release+then weakening” water injection softening measures and “first release+then guidance” drilling pressure relief measures are explained theoretically, respectively. However, we should focus on the defects of the corresponding control measures and finally try to make a reasonable combination of different modification measures. Finally, the gradient pressure relief scheme should be considered in order to avoid large stress drop caused by large-scale pressure relief in the region and aggravate the instability of rock mass. The instability of rock mass is further aggravated.

scholarly journals Influence of Mine Earthquake Disturbance on the Principal Stress of the Main Roadway near the Goaf and Its Prevention and Control Measures

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiazhuo Li ◽  
Penghui Guo ◽  
Heng Cui ◽  
Xiqing Hao ◽  
Lihua Tian ◽  
...  
Keyword(s):  
Principal Stress ◽  
Coal Mine ◽  
Prevention And Control ◽  
Mining Area ◽  
Surrounding Rock ◽  
Control Measures ◽  
Pressure Relief ◽  
Mining Depth ◽  
Prevention And Control Measures ◽  
And Control

With the reduction and depletion of shallow energy, the mining depth of coal around the world is increasing year by year, and the mining depth of some coal mines in China has reached kilometers. The main roadway near the goaf with the deep high static stress is very easy to be damaged after being disturbed by the mine earthquake. Taking the main roadway in the no. 1 mining area of Gaojiapu coal mine in Binchang mining area, Shaanxi Province, China, as the engineering background, the high-energy mine earthquake monitored by the on-site microseism is equivalently simulated through the dynamic module of FLAC3D, and the spatial-temporal rotation characteristics of the principal stress of roadway surrounding rock under the disturbance of mine earthquake are studied and analyzed and put forward corresponding prevention and control measures. Research shows early stage of mine earthquake disturbance, roadway roof is first affected, and the principal stress of the roof has the trend of deflection to the side of the goaf. In the middle stage of mine earthquake disturbance, the main body of roof principal stress deflects to the side of goaf, and the deflection range is large. In the later stage of mine earthquake disturbance, the principal stress directions in the surrounding rock reverse rotation, and the reverse rotation angle of the principal stress direction in the roof is the largest. Finally, the asymmetric distribution characteristics of principal stress rotation are verified by using the asymmetric deformation phenomenon on both sides of roadway surrounding rock. Based on the rotation characteristics of principal stress under the dual influence of mine earthquake disturbance and goaf, optimize the layout scheme and blasting parameters of blasting pressure relief holes. The transmission direction of principal stress can be changed by blasting pressure relief method; meanwhile, the transmission of principal stress can be blocked; through the comparison of microseismic activity law before and after pressure relief, pressure relief effect is good. The research results can provide a certain reference basis for coal mine roadway pressure relief and reducing disaster conditions.

Knowledge and Awareness of Dengue Fever

2018 ◽  
pp. 219-222
Author(s):  
Y. Arockia Suganthi ◽  
Chitra K. ◽  
J. Magelin Mary
Keyword(s):  
Dengue Fever ◽  
Prevention And Control ◽  
Control Measures ◽  
Infection Transmission ◽  
Standard Guideline ◽  
The World ◽  
Different Types ◽  
Prevention And Control Measures ◽  
Dengue Prevention ◽  
And Control

Dengue fever is a painful mosquito-borne infection caused by different types of virus in various localities of the world. There is no particular medicine or vaccine to treat person suffering from dengue fever. Dengue viruses are transmitted by the bite of female Aedes (Ae) mosquitoes. Dengue fever viruses are mainly transmitted by Aedes which can be active in tropical or subtropical climates. Aedes Aegypti is the key step to avoid infection transmission to save millions of people in all over the world. This paper provides a standard guideline in the planning of dengue prevention and control measures. At the same time gives the priorities including clinical management and hospitalized dengue patients have to address essentially.

An evaluation model of 2019-nCoV prevention effectiveness based on immigration data in China (Preprint)

2020 ◽  
Author(s):  
Qiangsheng Huang
Keyword(s):  
Prevention And Control ◽  
Time Window ◽  
Evaluation Model ◽  
Control Measures ◽  
Related Data ◽  
The Face ◽  
Prevention And Control Measures ◽  
And Control ◽  
Best Fit

BACKGROUND As of the end of February 2020, 2019-nCoV is currently well controlled in China. However, the virus is now spreading globally. OBJECTIVE This study aimed to evaluate the effectiveness of outbreak prevention and control measures in a region. METHODS A model is built for find the best fit for two sets of data (the number of daily new diagnosed, and the risk value of incoming immigration population). The parameters (offset and time window) in the model can be used as the evaluation of effectiveness of outbreak prevention and control. RESULTS Through study, it is found that the parameter offset and time window in the model can accurately reflect the prevention effectiveness. Some related data and public news confirm this result. And this method has advantages over the method using R0 in two aspects. CONCLUSIONS If the epidemic situation is well controlled, the virus is not terrible. Now the daily new diagnosed patients in most regions of China is quickly reduced to zero or close to zero. Chinese can do a good job in the face of huge epidemic pressure. Therefore, if other countries can do well in prevention and control, the epidemic in those places can also pass quickly.

Investigation on emotion and behavior of children aged 1-11 during the pandemic of COVID-19: A Cross-sectional study in Guizhou, China (Preprint)

2020 ◽  
Author(s):  
Yushi Mo ◽  
Yan Luo ◽  
Hong Li ◽  
Dewei Xiao ◽  
Shuqing Liu ◽  
...  
Keyword(s):  
Behavioral Problems ◽  
Prevention And Control ◽  
Online Survey ◽  
Sleep Problems ◽  
Emotional Problems ◽  
Control Measures ◽  
Emotional And Behavioral Problems ◽  
Guizhou Province ◽  
Cross Sectional ◽  
And Control

BACKGROUND In face of the sudden epidemic of COVID-19, strict prevention and control measures had been urgently carried out all over China. Because of the long-term home quarantine, all kinds of people were affected by it. OBJECTIVE In order to understand the mental health of children during the pandemic of COVID-19, this study investigated the prevalence and characteristics of emotional and behavioral problems of children aged 1-11 in Guizhou. METHODS Based on the online survey platform, the survey link was pushed through Wechat in April 2020. Electronic questionnaires were used to investigate children's demographic characteristics, emotional or behavioral problems. RESULTS A total of 3505 valid questionnaires were received from 9 prefectures and cities in Guizhou Province. 39.67% of the children in the 1-2-year-old group had emotional problems. 17.63% of the children agd 3-5 years had behavioral or emotional problems. And 23.57% of the children agd 6-11 years havd behavioral problems. CONCLUSIONS During the home quarantine period of prevention and control of COVID-19, even young children were adversely affected. The prevalence of emotional and behavioral problems in children was high, which was mainly manifested as anxiety, difficulty in concentration and sleep problems.

scholarly journals Spatio-temporal evolution and influencing mechanism of the COVID-19 epidemic in Shandong province, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinlong Shi ◽  
Xing Gao ◽  
Shuyan Xue ◽  
Fengqing Li ◽  
Qifan Nie ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Temporal Evolution ◽  
Geographical Location ◽  
Shandong Province ◽  
Control Measures ◽  
Middle Aged ◽  
Health Crisis ◽  
Aged People ◽  
Spatio Temporal ◽  
And Control

AbstractThe novel coronavirus pneumonia (COVID-19) outbreak that emerged in late 2019 has posed a severe threat to human health and social and economic development, and thus has become a major public health crisis affecting the world. The spread of COVID-19 in population and regions is a typical geographical process, which is worth discussing from the geographical perspective. This paper focuses on Shandong province, which has a high incidence, though the first Chinese confirmed case was reported from Hubei province. Based on the data of reported confirmed cases and the detailed information of cases collected manually, we used text analysis, mathematical statistics and spatial analysis to reveal the demographic characteristics of confirmed cases and the spatio-temporal evolution process of the epidemic, and to explore the comprehensive mechanism of epidemic evolution and prevention and control. The results show that: (1) the incidence rate of COVID-19 in Shandong is 0.76/100,000. The majority of confirmed cases are old and middle-aged people who are infected by the intra-province diffusion, followed by young and middle-aged people who are infected outside the province. (2) Up to February 5, the number of daily confirmed cases shows a trend of “rapid increase before slowing down”, among which, the changes of age and gender are closely related to population migration, epidemic characteristics and intervention measures. (3) Affected by the regional economy and population, the spatial distribution of the confirmed cases is obviously unbalanced, with the cluster pattern of “high–low” and “low–high”. (4) The evolution of the migration pattern, affected by the geographical location of Wuhan and Chinese traditional culture, is dominated by “cross-provincial” and “intra-provincial” direct flow, and generally shows the trend of “southwest → northeast”. Finally, combined with the targeted countermeasures of “source-flow-sink”, the comprehensive mechanism of COVID-19 epidemic evolution and prevention and control in Shandong is revealed. External and internal prevention and control measures are also figured out.

scholarly journals Evaluating the effectiveness of measures to control the novel coronavirus disease 2019 in Jilin Province, China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qinglong Zhao ◽  
Yao Wang ◽  
Meng Yang ◽  
Meina Li ◽  
Zeyu Zhao ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Good Control ◽  
Asymptomatic Infection ◽  
Jilin Province ◽  
Control Measures ◽  
First Case ◽  
Before And After ◽  
Novel Coronavirus ◽  
Reported Data ◽  
And Control

Abstract Background Based on differences in populations and prevention and control measures, the spread of new coronary pneumonia in different countries and regions also differs. This study aimed to calculate the transmissibility of coronavirus disease 2019 (COVID-19), and to evaluate the effectiveness of measures to control the disease in Jilin Province, China. Methods The data of reported COVID-19 cases were collected, including imported and local cases from Jilin Province as of March 14, 2019. A Susceptible–Exposed–Infectious–Asymptomatic–Recovered/Removed (SEIAR) model was developed to fit the data, and the effective reproduction number (Reff) was calculated at different stages in the province. Finally, the effectiveness of the measures was assessed. Results A total of 97 COVID-19 infections were reported in Jilin Province, among which 45 were imported infections (including one asymptomatic infection) and 52 were local infections (including three asymptomatic infections). The model fit the reported data well (R2 = 0.593, P < 0.001). The Reff of COVID-19 before and after February 1, 2020 was 1.64 and 0.05, respectively. Without the intervention taken on February 1, 2020, the predicted cases would have reached a peak of 177,011 on October 22, 2020 (284 days from the first case). The projected number of cases until the end of the outbreak (on October 9, 2021) would have been 17,129,367, with a total attack rate of 63.66%. Based on the comparison between the predicted incidence of the model and the actual incidence, the comprehensive intervention measures implemented in Jilin Province on February 1 reduced the incidence of cases by 99.99%. Therefore, according to the current measures and implementation efforts, Jilin Province can achieve good control of the virus’s spread. Conclusions COVID-19 has a moderate transmissibility in Jilin Province, China. The interventions implemented in the province had proven effective; increasing social distancing and a rapid response by the prevention and control system will help control the spread of the disease.

scholarly journals Heterogeneity and effectiveness analysis of COVID-19 prevention and control in major cities in China through time-varying reproduction number estimation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qing Cheng ◽  
Zeyi Liu ◽  
Guangquan Cheng ◽  
Jincai Huang
Keyword(s):  
Prevention And Control ◽  
Large Scale ◽  
Reproduction Number ◽  
Correlation Method ◽  
Control Measures ◽  
Time Varying ◽  
Short Period ◽  
Significant Difference ◽  
Prevention And Control Measures ◽  
And Control

AbstractBeginning on December 31, 2019, the large-scale novel coronavirus disease 2019 (COVID-19) emerged in China. Tracking and analysing the heterogeneity and effectiveness of cities’ prevention and control of the COVID-19 epidemic is essential to design and adjust epidemic prevention and control measures. The number of newly confirmed cases in 25 of China’s most-affected cities for the COVID-19 epidemic from January 11 to February 10 was collected. The heterogeneity and effectiveness of these 25 cities’ prevention and control measures for COVID-19 were analysed by using an estimated time-varying reproduction number method and a serial correlation method. The results showed that the effective reproduction number (R) in 25 cities showed a downward trend overall, but there was a significant difference in the R change trends among cities, indicating that there was heterogeneity in the spread and control of COVID-19 in cities. Moreover, the COVID-19 control in 21 of 25 cities was effective, and the risk of infection decreased because their R had dropped below 1 by February 10, 2020. In contrast, the cities of Wuhan, Tianmen, Ezhou and Enshi still had difficulty effectively controlling the COVID-19 epidemic in a short period of time because their R was greater than 1.

scholarly journals Improving knowledge, attitudes and practice to prevent COVID-19 transmission in healthcare workers and the public in Thailand

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rapeephan R. Maude ◽  
Monnaphat Jongdeepaisal ◽  
Sumawadee Skuntaniyom ◽  
Thanomvong Muntajit ◽  
Stuart D. Blacksell ◽  
...  
Keyword(s):  
General Public ◽  
Prevention And Control ◽  
Healthcare Workers ◽  
Infection Prevention ◽  
Control Measures ◽  
Infection Prevention And Control ◽  
The Public ◽  
Educational Videos ◽  
Prevention And Control Measures ◽  
And Control

Abstract Background Key infection prevention and control measures to limit transmission of COVID-19 include social distancing, hand hygiene, use of facemasks and personal protective equipment. However, these have limited or no impact if not applied correctly through lack of knowledge, inappropriate attitude or incorrect practice. In order to maximise the impact of infection prevention and control measures on COVID-19 spread, we undertook a study to assess and improve knowledge, attitudes and practice among 119 healthcare workers and 100 general public in Thailand. The study setting was two inpatient hospitals providing COVID-19 testing and treatment. Detailed information on knowledge, attitudes and practice among the general public and healthcare workers regarding COVID-19 transmission and its prevention were obtained from a combination of questionnaires and observations. Results Knowledge of the main transmission routes, commonest symptoms and recommended prevention methods was mostly very high (> 80%) in both groups. There was lower awareness of aerosols, food and drink and pets as sources of transmission; of the correct duration for handwashing; recommended distance for social/physical distancing; and about recommended types of face coverings. Information sources most used and most trusted were the workplace, work colleagues, health workers and television. The results were used to produce a set of targeted educational videos which addressed many of these gaps with subsequent improvements on retesting in a number of areas. This included improvements in handwashing practice with an increase in the number of areas correctly washed in 65.5% of the public, and 57.9% of healthcare workers. The videos were then further optimized with feedback from participants followed by another round of retesting. Conclusions Detailed information on gaps in knowledge, attitudes and practice among the general public and healthcare workers regarding COVID-19 transmission and its prevention were obtained from a combination of questionnaires and observations. This was used to produce targeted educational videos which addressed these gaps with subsequent improvements on retesting. The resulting videos were then disseminated as a resource to aid in efforts to fight COVID-19 in Thailand and worldwide.

scholarly journals COVID-19 in South Korea: Proper timing for Easing Mask mandates after COVID-19 Vaccination

2021 ◽  
pp. 1-9
Author(s):  
Yun-Jung Kang
Keyword(s):  
South Korea ◽  
Disease Control ◽  
Prevention And Control ◽  
Control Measures ◽  
Social Distancing ◽  
Proper Timing ◽  
Control And Prevention ◽  
Prevention And Control Measures ◽  
And Control

Abstract As of 25 July 2021, the Korea Disease Control and Prevention Agency reported 1,422 new COVID-19 cases, 188,848 total cases, and 2.073 total deaths (1.10% fatality rates). Since the first SARS-CoV-2 case was reported, efforts to find a treatment and vaccine against COVID-19 have been widespread. Four vaccines are on the WHO’s emergency use listing and are approved of their usage; BNT162b2, mRNA-1273, AZD1222, and Ad26.COV2.S. Vaccines against SARS-CoV-2 need at least 14 days to achieve effectiveness. Thus, people should abide by prevention and control measures, including wearing masks, washing hands, and social distancing. However, a lot of new cases were reported after vaccinations, as many people did not follow the prevention control measures before the end of the 14 days period. There is no doubt we need to break free from mask mandates. But let us not decide the timing in haste. Even if the mask mandates are eased, they should be changed depending on the number of reported cases, vaccinations, as well as prevention and control measures on how circumstances are changing under the influence of mutant coronavirus.

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