The bolt support quality of coal roadways is one of the important factors for the efficiency and security of coal production. By means of a self-developed technique and equipment of random non-destructive testing, non...The bolt support quality of coal roadways is one of the important factors for the efficiency and security of coal production. By means of a self-developed technique and equipment of random non-destructive testing, non-destructive detection and pre-warning analysis on the quality of bolt support in deep roadways of mining districts were performed in a number of mining areas. The measured data were obtained in the detection instances of abnormal in-situ stress and support invalidation etc. The corresponding relation between axial bolt load variation and roadway surrounding rock deformation and stability was summarized in different mining service stages. Pre-warning technology of roadway surrounding rock stability is proposed based on the detection of axial bolt load. Meanwhile, pre-warning indicators of axial bolt load in different mining service stages are offered and some successful pre-warning cases are also illustrated.The research results show that the change rules of axial bolt load in different mining service stages are quite similar in different mining areas. The change of axial bolt load is in accord with the adjustment of surrounding rock stress, which can consequently reflect the deformation and stability state of roadway surrounding rock. Through the detection of axial bolt load in different sections of roadways, the status of real-time bolt support quality can be reflected; meanwhile, the rationality of bolt support design can be evaluated which provides reference for bolting parameters optimization.展开更多
Objective:To elucidate the awareness and approach to pre-operative human immunodeficiency virus(HIV) testing and emphasis on the attendant components of HIV testing.Methods: The study was conducted at the theatres of ...Objective:To elucidate the awareness and approach to pre-operative human immunodeficiency virus(HIV) testing and emphasis on the attendant components of HIV testing.Methods: The study was conducted at the theatres of the University of Port Harcourt Teaching Hospital among 123 nursing,anaesthetic,and operating staff.A descriptive cross sectional design was adopted with stratified sampling.The study instrument was a structured,self administered pro forma.Results:All respondents were all aware of HIV infection and all had transmission through infected blood and tissues(100.0%).88.6%had infection through needle stick injuries, 62.6%through vertical transmission,and 98.4%through blood transfusion.Sixty three percent of respondents correctly knew what preoperative testing was,while 58.5%were aware of the preoperative testing policy of the hospital.All respondents favoured the policy of preoperative testing.Attitudinal values to seropositive patients were not very different as 72.4%of respondents claimed they treated every patient as high risk,and all respondents used personal protective equipment.Conclusions:Routine HIV testing now represents a conventional means providing patients with knowledge of their HIV status.Such testing should be accompanied by informed consent,counselling,confidentiality,protection,and access to treatment.展开更多
基金the State Key Research Development Program of China(No.2016YFC0600705)the Fundamental Research Funds for the Central Universities(No.2015XKZD06)+1 种基金the National Natural Science Foundation of China(Nos.51227003,51404250,51504243,51474215,51404262 and 51323004)the Natural Science Foundation of Jiangsu Province,China(Nos.BK20150191 and BK20140213)
文摘The bolt support quality of coal roadways is one of the important factors for the efficiency and security of coal production. By means of a self-developed technique and equipment of random non-destructive testing, non-destructive detection and pre-warning analysis on the quality of bolt support in deep roadways of mining districts were performed in a number of mining areas. The measured data were obtained in the detection instances of abnormal in-situ stress and support invalidation etc. The corresponding relation between axial bolt load variation and roadway surrounding rock deformation and stability was summarized in different mining service stages. Pre-warning technology of roadway surrounding rock stability is proposed based on the detection of axial bolt load. Meanwhile, pre-warning indicators of axial bolt load in different mining service stages are offered and some successful pre-warning cases are also illustrated.The research results show that the change rules of axial bolt load in different mining service stages are quite similar in different mining areas. The change of axial bolt load is in accord with the adjustment of surrounding rock stress, which can consequently reflect the deformation and stability state of roadway surrounding rock. Through the detection of axial bolt load in different sections of roadways, the status of real-time bolt support quality can be reflected; meanwhile, the rationality of bolt support design can be evaluated which provides reference for bolting parameters optimization.
文摘Objective:To elucidate the awareness and approach to pre-operative human immunodeficiency virus(HIV) testing and emphasis on the attendant components of HIV testing.Methods: The study was conducted at the theatres of the University of Port Harcourt Teaching Hospital among 123 nursing,anaesthetic,and operating staff.A descriptive cross sectional design was adopted with stratified sampling.The study instrument was a structured,self administered pro forma.Results:All respondents were all aware of HIV infection and all had transmission through infected blood and tissues(100.0%).88.6%had infection through needle stick injuries, 62.6%through vertical transmission,and 98.4%through blood transfusion.Sixty three percent of respondents correctly knew what preoperative testing was,while 58.5%were aware of the preoperative testing policy of the hospital.All respondents favoured the policy of preoperative testing.Attitudinal values to seropositive patients were not very different as 72.4%of respondents claimed they treated every patient as high risk,and all respondents used personal protective equipment.Conclusions:Routine HIV testing now represents a conventional means providing patients with knowledge of their HIV status.Such testing should be accompanied by informed consent,counselling,confidentiality,protection,and access to treatment.
