期刊文献+
共找到5,369篇文章
< 1 2 250 >
每页显示 20 50 100
Hydrogeochemical Characterization of Groundwater from Fissured Aquifers in the Angovia Mine Operating Permit Area (Central-West Côte d’Ivoire)
1
作者 Kouadio Michel Yao Tanina Drissa Soro +3 位作者 Tanoh Jean Jacques Koua Akaie Jean Fabrice Tchakray Yao Emile Desmond Konan Brou Dibi 《Journal of Water Resource and Protection》 CAS 2024年第1期83-101,共19页
The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoi... The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoire. To do so, descriptive and multivariate statistical analysis methods with the SOM (Self Organizing Maps) algorithm were applied to the physicochemical parameters of 17 boreholes using the calcite (ISC) and dolomite (ISD) saturation indices. The results obtained have shown that the groundwater in the Angovia mine operating permit area has an average temperature of 27.52°C (long rainy season) and 27.87&degC (long dry season) and has an average pH of 7.09 ± 0.35 during the main rainy season and 7.32 ± 0.35 during the main dry season. They are mineralized with an average electrical conductivity of 505.98 ± 302.85 μS/cm during the long rainy season and with 450.33 ± 233.74 μS/cm as average during the long dry season. The main phenomena at the origin of groundwater mineralization are water residence time, oxidation-reduction and surface inflow. The study of the relative age of the water shows that the groundwater in the Angovia mine operating permit area is mainly undersaturated with respect to calcite and dolomite. They are therefore very old in the aquifer with a slow circulation speed during the long rainy season and the long dry season. 展开更多
关键词 HYDROGEOCHEMISTRY MINERALIZATION fissure Aquifers Operating Permits The Angovia Mine
下载PDF
Heat transfer and temperature evolution in underground mininginduced overburden fracture and ground fissures: Optimal time window of UAV infrared monitoring
2
作者 Yixin Zhao Kangning Zhang +2 位作者 Bo Sun Chunwei Ling Jihong Guo 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期31-50,共20页
Heat transfer and temperature evolution in overburden fracture and ground fissures are one of the essential topics for the identification of ground fissures via unmanned aerial vehicle(UAV) infrared imager. In this st... Heat transfer and temperature evolution in overburden fracture and ground fissures are one of the essential topics for the identification of ground fissures via unmanned aerial vehicle(UAV) infrared imager. In this study, discrete element software UDEC was employed to investigate the overburden fracture field under different mining conditions. Multiphysics software COMSOL were employed to investigate heat transfer and temperature evolution of overburden fracture and ground fissures under the influence of mining condition, fissure depth, fissure width, and month alternation. The UAV infrared field measurements also provided a calibration for numerical simulation. The results showed that for ground fissures connected to underground goaf(Fissure Ⅰ), the temperature difference increased with larger mining height and shallow buried depth. In addition, Fissure Ⅰ located in the boundary of the goaf have a greater temperature difference and is easier to be identified than fissures located above the mining goaf. For ground fissures having no connection to underground goaf(Fissure Ⅱ), the heat transfer is affected by the internal resistance of the overlying strata fracture when the depth of Fissure Ⅱ is greater than10 m, the temperature of Fissure Ⅱ gradually equals to the ground temperature as the fissures’ depth increases, and the fissures are difficult to be identified. The identification effect is most obvious for fissures larger than 16 cm under the same depth. In spring and summer, UAV infrared identification of mining fissures should be carried out during nighttime. This study provides the basis for the optimal time and season for the UAV infrared identification of different types of mining ground fissures. 展开更多
关键词 Heat transfer Overburden fracture Ground fissures Infrared thermal imaging Unmanned aerial vehicle(UAV) COMSOL simulation
下载PDF
Performances of fissured red sandstone after thermal treatment with constant-amplitude and low-cycle impacts
3
作者 Yongjun Chen Tubing Yin +3 位作者 P.G.Ranjith Xibing Li Qiang Li Dengdeng Zhuang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第2期561-587,共27页
In the engineering practices,it is increasingly common to encounter fractured rocks perturbed by temperatures and frequent dynamic loads.In this paper,the dynamic behaviors and fracture characteristics of red sandston... In the engineering practices,it is increasingly common to encounter fractured rocks perturbed by temperatures and frequent dynamic loads.In this paper,the dynamic behaviors and fracture characteristics of red sandstone considering temperatures(25℃,200℃,400℃,600℃,and 800℃)and fissure angles(0°,30°,60°,and 90°)were evaluated under constant-amplitude and low-cycle(CALC)impacts actuated by a modified split Hopkinson pressure bar(SHPB)system.Subsequently,fracture morphology and second-order statistics within the grey-level co-occurrence matrix(GLCM)were examined using scanning electron microscopy(SEM).Meanwhile,the deep analysis and discussion of the mechanical response were conducted through the synchronous thermal analyzer(STA)test,numerical simulations,one-dimensional stress wave theory,and material structure.The multiple regression models between response variables and interactive effects of independent variables were established using the response surface method(RSM).The results demonstrate the fatigue strength and life diminish as temperatures rise and increase with increasing fissure angles,while the strain rate exhibits an inverse behavior.Furthermore,the peak stress intensification and strain rate softening observed during CALC impact exhibit greater prominence at increased fissure angles.The failure is dominated by tensile damage with concise evolution paths and intergranular cracks as well as the compressor-crushed zone which may affect the failure mode after 400℃.The second-order statistics of GLCM in SEM images exhibit a considerable dependence on the temperatures.Also,thermal damage dominated by thermal properties controls the material structure and wave impedance and eventually affects the incident wave intensity.The tensile wave reflected from the fissure surface is the inherent mechanism responsible for the angle effect exhibited by the fatigue strength and life.Ultimately,the peak stress intensification and strain rate softening during impact are determined by both the material structure and compaction governed by thermal damage and tensile wave. 展开更多
关键词 Red sandstone Temperature fissure Constant-amplitude and low-cycle(CALC) impact Fatigue failure Response surface method(RSM)
下载PDF
Research on the feasibility of storage and estimation model of storage capacity of CO_(2)in fissures of coal mine old goaf 被引量:1
4
作者 Yang Ding Shugang Li +4 位作者 Bing Zhu Haifei Lin Jingfei Zhang Junhong Tan Wenbin Chen 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第6期675-686,共12页
The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and... The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and associated gas resources development.Firstly,the evolution characteristics of overburden fissures in the goaf of the case was studied using a two-dimensional physical similarity simulation test,the sealing performance of the caprocks after stabilization was analyzed,and the fissures were counted and classi-fied.Then,the process of gaseous CO_(2)injection in the connected fissure was simulated by Ansys Fluent software,and the migration law and distribution characteristics of CO_(2)under the condition of gaseous CO_(2)injection were analyzed.Finally,the estimation models of free CO_(2)storage capacity in the old goaf were constructed considering the proportion of connected fissure and the effectiveness of CO_(2)injection.The CO_(2)storage capacity in the old goaf of the case coal mine was estimated.The results showed that a caprock group of“hard-thickness low-permeability hard-thickness”was formed after the caprock-fissures system in the goaf of the case tended to be stable vertically.The connected fissure,occlude cracks,and micro-fractures in the goaf accounted for 85.5%,8.5%,and 6%of the total fissures,respectively.Gaseous CO_(2)first migrated to the bottom of the connected fissure after CO_(2)was injected into the goaf,then spread horizontally along the bottom of the connected fissure after reaching the bottom,and finally spread longitudinally after filling the bottom of the entire connected fissure.The theoretical and effective storage capacities of free CO_(2)at normal temperature and pressure in the old goaf of the case were 9757 and 7477 t,respectively.The effective storage capacity of free CO_(2)at normal temperature and pressure in the old goaf after all minefield mined was 193404 t.The research can provide some reference for the coal mining industry to help the goal of“carbon peaking and carbon neutrality”. 展开更多
关键词 Carbon cycle Old goaf fissure CO_(2)storage FEASIBILITY Storage capacity
下载PDF
Automated identification of fissure trace in mining roadway via deep learning
5
作者 Yuxin Yuan Nong Zhang +1 位作者 Changliang Han Dongxu Liang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第8期2039-2052,共14页
The fractured rocks distributed near the structural surface of coal roadway heading face can easily cause water or air conduits,ultimately resulting in accidents that threaten production safety,such as mine flooding,g... The fractured rocks distributed near the structural surface of coal roadway heading face can easily cause water or air conduits,ultimately resulting in accidents that threaten production safety,such as mine flooding,gas leakage,or supporting failure.Therefore,successful detection of fissures is crucial to mine safety.Despite the rising popularity of computer vision in accurate fissures detection,it fails to satisfy the demand of engineering practice.To address this problem,this paper first establishes a 1000-image database of fissures of coal roadway heading face based on data collection,cleaning,and annotation.Then,a framework for fissure detection and segmentation is constructed with deep convolutional neural network(DCNN)named DeepLabv3+ serving as the overall architecture,and a lightweight MobileNetV2,instead of the original Xception,as the main feature extraction network.The database is then employed to train and test the neural network model.Finally,the robustness and adaptability of the model under the common jamming environment in coal mines are evaluated.According to the results,the deep learning algorithm,which performs favorably in identifying various fissures in the coal roadway heading face,is immune to interference such as low illumination,wire mesh,multi-scale edge,cutting mark,and concentrated light beams.Notably,the performance of such method is on par with,or better than,humans in performing individual image segmentation.The approach performs higher segmentation accuracy and calculation speed than the traditional image identification algorithm,thus realizing rapid identification of fissures in coal mines in batch.This study can provide a reference for image semantic segmentation of fissure traces under similar conditions. 展开更多
关键词 Intelligent driving Computer vision fissure evaluation DeepLabv3+ MobileNetV2
下载PDF
Evaluation of the Efficacy of 99.9% Pure Silver Trilaminate Cups in the Prevention and Treatment of Nipple Pain and Fissures
6
作者 Monica Pilloni Pierina Zedda +8 位作者 Carla Orrù Elena Fassina Maria Carmela Forte Rossana Mazzulla Brunella Celestino Maria Francesca Marotto Manuela Neri Gian Benedetto Melis Anna Maria Paoletti 《Open Journal of Nursing》 2023年第10期686-698,共13页
Breastfeeding is drastically decreasing over time and nipple trauma constitutes one of the most significant reasons for its discontinuation. In this context, this study aimed at evaluating the effectiveness and tolera... Breastfeeding is drastically decreasing over time and nipple trauma constitutes one of the most significant reasons for its discontinuation. In this context, this study aimed at evaluating the effectiveness and tolerability of a topical treatment device, namely Silver Cap<sup>®</sup> (Depofarma S.P.A.), when used to prevent pain and nipple fissure formation. The medical device consists in a silver trilaminate cup to be placed on the nipple, providing physical protection and creating a moist environment. The study involved 187 women: 38 started to apply the device prior to lactation (PL group) and 149 during lactation (DL group). Aiming to collect safety and performance data, both groups were provided with questionnaires during 6 consecutive visits (120 days of follow-up). At last visit, absence of painful symptoms was reported by the 98.8% and the 100% of women in DL and PL groups, respectively. Moreover, no nipple fissures were observed and no adverse events directly correlated to use of the device were reported. According to these findings, it can be concluded that Silver Cap<sup>®</sup> is a safe and effective device for nipple pain and fissure prevention. . 展开更多
关键词 Silver Cap BREASTFEEDING Breast Pain Nipple fissures
下载PDF
Ground fissure development regularity and formation mechanism of shallow buried coal seam mining with Karst landform in Jiaozi coal mine: a case study
7
作者 ZHU Heng-zhong 《Journal of Mountain Science》 SCIE CSCD 2023年第10期3101-3120,共20页
A comprehensive study was undertaken at Jiaozi coal mine to investigate the development regularity of ground fissures in shallow buried coal seam mining with Karst landform,shedding light on the development type,geogr... A comprehensive study was undertaken at Jiaozi coal mine to investigate the development regularity of ground fissures in shallow buried coal seam mining with Karst landform,shedding light on the development type,geographical distribution,dynamic development process,and failure mechanism of these ground fissures by employing field monitoring,numerical simulation,and theoretical analysis.The findings demonstrate that ground fissure development has an obvious feature of subregion,and its geographical distribution is significantly affected by topography.Tensile type,open type,and stepped type are three different categories of ground fissure.Ground fissures emerge dynamically as the panel advances,and they typically develop with a distance of less than periodic weighting step distance in advance of panel advancing position.Ground fissures present the dynamic development feature,temporary fissure has the ability of self-healing.The dynamic development process of ground fissure with closed-distance coal seam repeated mining is expounded,and the development scale is a dynamic development stage of“closure→expansion→stabilized”on the basis of the original development scale.From the perspective of topsoil deformation,the computation model considering two points movement vectors towards two directions of the gob and the ground surface is established,the development criterion considering the critical deformation value of topsoil is obtained.The mechanical model of hinged structure of inclined body is proposed to clarify the ground fissure development,and the interaction between slope activity and ground fissure development is expounded.These research results fulfill the gap of ground fissures about development regularity and formation mechanism,and can contribute to ground fissure prevention and treatment with Karst landform. 展开更多
关键词 Karst landform Shallow buried coal seam Development regularity Formation mechanism Ground fissure Repeated mining
下载PDF
Microtremor-based analysis of the dynamic response characteristics of a site containing grouped earth fissures
8
作者 Deng Yahong Xuan You +5 位作者 Mu Huandong Chang Jiang Cao Ge He Nainan Zhao Xunchang Sun Longfei 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期689-702,共14页
In this study,the Beibu earth fissure site in the northeastern part of Weihe Basin,which contains four nearly parallel earth fissures,was studied.A long straight microtremor measuring line,containing 49 measuring poin... In this study,the Beibu earth fissure site in the northeastern part of Weihe Basin,which contains four nearly parallel earth fissures,was studied.A long straight microtremor measuring line,containing 49 measuring points across four earth fissures,was established to investigate the dynamic response of this site using Fourier spectrum,response acceleration spectrum,Arias intensity,and HVSR analyses.The main results are as follows:(1)The fundamental frequencies of 44 measuring points obtained from HVSR analysis are concentrated within 1.67 Hz-2.25 Hz,and the existence of the earth fissures has little effect on the fundamental frequency changes.(2)There is an amplification effect near a single earth fissure.The dynamic responses are large at the measuring points near the earth fissure,and the values decrease with increasing distance from the earth fissure.In areas between two adjacent earth fissures,these values decrease and are even lower than those in sites without amplification effects.(3)In this earth fissure site,the general area(or less affected area)and affected areas were delineated based on the amplification effect.In engineering applications,construction design should avoid these affected areas and existing structures should be reinforced to satisfy the seismic fortification requirements. 展开更多
关键词 earth fissure sites MICROTREMORS Fourier amplitude spectrum response spectrum arias intensity H/V spectral ratio fundamental frequency amplification effect
下载PDF
Comparative analysis of Parikartika and Anal Fissure: unraveling diagnostic, therapeutic, and surgical dimensions
9
作者 Sandeep Kumar Upadhyay Sheetal Asutkar Shreya Soni 《Clinical Research Communications》 2023年第4期1-9,共9页
Background:Agnimandya,the underlying cause of anorectal disorders,of which Parikartika is the most well-known,is brought on by lifestyles characterized by sedentary behavior,elevated stress,poor nutrition,and sleep ha... Background:Agnimandya,the underlying cause of anorectal disorders,of which Parikartika is the most well-known,is brought on by lifestyles characterized by sedentary behavior,elevated stress,poor nutrition,and sleep habits.The illness known as Parikartika,with signs and symptoms like fissure-in-ano in modern sources,is characterized by kartanvat Vedana(cutting pain)over the anal region.Acute fissure-in-ano is treated with analgesics,stool softeners,and soothing creams.Treatment options for hazy chronic fissures include anal dilatation,sphincterotomy,fissurectomy,and anal advancement flap.In addition to using laxatives and substances that promote wound healing(vranaropaka),the concepts of management of Parikartika in Ayurveda are more heavily weighted towards enhancing the nature,character,and consistency of stool and stabilizing the digestive functions Parikartika is mentioned in Ayurvedic texts as a complication of many Ayurvedic procedures,such as Vamana,Virechana,and Basti,as well as a complication of some disorders,such as Arsh,Atisar,and Grahani.Aim and objective:This article aims to comprehensively review the literature,diagnostic,and therapeutic aspects of Parikartika,with its correlation to Fissure in ano,and compare the clinical outcomes of the treatment modalities with supporting references,consolidating all pertinent information on the subject.Material&method:Collection from Samhita’s,commentaries,exploring medical websites,Ayurvedic journals related to the topic of Parikartika and fissure in ano,systematic record of the collected literature and a summary of each item.Organize the collected materials,reference and citation are the material and method followed here.Discussion&conclusion:This is an extensive literature review on Parikartika in Ayurveda,exploring its contemporary association with Fissure in Ano.The research offers insights that can inform the evaluation and treatment of this condition,considering both conservative and surgical approaches,thereby enhancing clinical management strategies. 展开更多
关键词 ANORECTAL botulinum toxin Anal fissure anal spasm sentinel tag Gudaparikartika SPHINCTEROTOMY
下载PDF
DAMAGE MODEL OF CONTROL FISSURE IN PERILOUS ROCK 被引量:7
10
作者 陈洪凯 唐红梅 叶四桥 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第7期967-974,共8页
Hitherto, perilous rock is the weakest topic in disasters studies. Specially, damage of control fissure under loads is one key technique in study of develop mechanism of perilous rock. Damage division of end area of c... Hitherto, perilous rock is the weakest topic in disasters studies. Specially, damage of control fissure under loads is one key technique in study of develop mechanism of perilous rock. Damage division of end area of control fissure was defined by authors, then calculation methods of timed-Poisson's ratio and timed-Young's modulus were established in damage mechanics theory. Further, the authors set up damage constitutive equation of control fissure, which founds important basis to numerical simulation for control fissure to develop. 展开更多
关键词 perilous rock control fissure damage area damage model APPLICATION
下载PDF
Fracture evolution characteristics of sandstone containing double fissures and a single circular hole under uniaxial compression 被引量:13
11
作者 Chen Minliang Jing Hongwen +3 位作者 Ma Xiujun Su Haijian Du Mingrui Zhu Tantan 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期499-505,共7页
The uniaxial compression experiments on the sandstone samples containing double fissures and a single circular hole were carried out by using electro-hydraulic servo universal testing machine to investigate the effect... The uniaxial compression experiments on the sandstone samples containing double fissures and a single circular hole were carried out by using electro-hydraulic servo universal testing machine to investigate the effect of rock bridge angle β and fissure angle α on mechanical properties and evolution characteristics of cracks.The results show that the peak strength,peak strain and elastic modulus of defected specimens decrease comparing with those for intact sample,and show a decreased trend firstly and then increase with β changing from 0° to 90°.The peak strength and elastic modulus achieve the minimum value as the rock bridge angle is 60°,while the peak strain reaches the minimum value with the rock bridge angle of 45°.The crack initiation of tested rock samples occurs firstly in stress concentration areas at tips of prefabricated fissures under uniaxial compression,and then propagates constantly and coalescences with the prefabricated hole.Some secondary cracks initiate and propagate as well until buckling failure happens.The rock bridge angle has a great influence on crack initiation,coalescence,final failure mode,crack initiation stress and transfixion stress.The peak strength varies significantly,while the elastic modulus and peak strain change slightly,and the failure modes are also different due to the influence of fissure angle. 展开更多
关键词 Double fissures A single circular hole Strength characteristics Crack propagation Failure mode
下载PDF
Coal and rock fissure evolution and distribution characteristics of multi-seam mining 被引量:11
12
作者 Zhang Dongming Qi Xiaohan +1 位作者 Yin Guangzhi Zheng Binbin 《International Journal of Mining Science and Technology》 SCIE EI 2013年第6期835-840,共6页
Henan Pingdingshan No.10 mine is prone to both coal and gas outbursts.The E_(9-10)coal seam is the main coal-producing seam but has poor quality ventilation,thus making it relatively difficult for gas extraction.The F... Henan Pingdingshan No.10 mine is prone to both coal and gas outbursts.The E_(9-10)coal seam is the main coal-producing seam but has poor quality ventilation,thus making it relatively difficult for gas extraction.The F_(15)coal seam,at its lower section,is not prone to coal and gas outbursts.The average seam separation distance of 150 m is greater than the upper limit for underside protective seam mining.Based on borehole imaging technology for field exploration of coal and rock fracture characteristics and discrete element numerical simulation,we have studied the evolution laws and distribution characteristics of the coal and rock fissure field between these two coal seams.By analysis of the influential effect of group F coal mining on the E_(9-10)coal seam,we have shown that a number of small fissures also develop in the area some 150 m above the overlying strata.The width and number of the fissures also increase with the extent of mining activity.Most of the fissures develop at a low angle or even parallel to the strata.The results show that the mining of the F_(15)coal seam has the effect of improving the permeability of the E_(9-10)coal seam. 展开更多
关键词 Multi-seam mining Evolution of fissure field Borehole imaging Numerical simulation
下载PDF
Discrete element modeling on the crack evolution behavior of brittle sandstone containing three fissures under uniaxial compression 被引量:11
13
作者 Sheng-Qi Yang Yan-Hua Huang +2 位作者 P.G.Ranjith Yu-Yong Jiao Jian Ji 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第6期871-889,共19页
Based on experimental restilts of brittle, intact sandstone under uniaxial compression, the micro-parameters were firstly confirmed by adopting particle flow code (PFC2D). Then, the validation of the simulated model... Based on experimental restilts of brittle, intact sandstone under uniaxial compression, the micro-parameters were firstly confirmed by adopting particle flow code (PFC2D). Then, the validation of the simulated models were cross checked with the experimental results of brittle sandstone containing three parallel fissures under uniaxial compression. The simulated results agreed very well with the experimental results, including the peak strength, peak axial strain, and ultimate failure mode. Using the same micro- parameters, the numerical models containing a new geometry of three fissures are constructed to investigate the fissure angle on the fracture mechanical behavior of brittle sandstone under uniaxial compression. The strength and deformation parameters of brittle sandstone containing new three fissures are dependent to the fissure angle. With the increase of the fis- sure angle, the elastic modulus, the crack damage threshold, and the peak strength of brittle sandstone containing three fissures firstly increase and secondly decrease. But the peak axial strain is nonlinearly related to the fissure angle. In the entire process of deformation, the crack initiation and propagation behavior of brittle sandstone containing three fissures under uniaxial compression are investigated with respect to the fissure angle. Six different crack coalescence modes are identified for brittle sandstone containing three fissures under uniaxial compression. The influence of the fissure angle on the length of crack propagation and crack coalescence stress is evaluated. These investigated conclusions are very important for ensuring the stability and safety of rock engineering with intermittent structures. 展开更多
关键词 Brittle sandstone ·PFC2D Three fissures ·Crack initiation Crack propagation Crack coalescence
下载PDF
Method to calculate fatigue fracture life of control fissure in perilous rock 被引量:5
14
作者 陈洪凯 唐红梅 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第5期643-649,共7页
Rupture and safety of perilous rock are dominated by control fissure behind perilous rock block. Based on model-Ⅰ and model-Ⅱ stress strength factors of control fissure under acting of weight of perilous rock, water... Rupture and safety of perilous rock are dominated by control fissure behind perilous rock block. Based on model-Ⅰ and model-Ⅱ stress strength factors of control fissure under acting of weight of perilous rock, water pressure in control fissure and earth- quake forces, method to calculate critical linking length of control fissure is established. Take water pressure in control fissure as a variable periodic load, and abide by P-M criterion, when control fissure is filled with water, establish the method to calculate fatigue fracture life of control fissure in critical status by contributing value of stress strength factor stemming from water pressure of control fissure in Paris's fatigue equation. Further, parameters (C and m) of sandstone with quartz and feldspar in the area of the Three Gorges Reservoir of China are obtained by fatigue fracture testing. 展开更多
关键词 perilous rock control fissure fatigue fracture LIFE
下载PDF
Resin infiltration of deproteinised natural occlusal subsurface lesions improves initial quality of fissure sealing 被引量:4
15
作者 Andrej M Kielbassa Ina Ulrich +3 位作者 Rita Schmidl Christoph Schuller Wilhelm Frank Vanessa D Werth 《International Journal of Oral Science》 SCIE CAS CSCD 2017年第2期117-124,共8页
The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin(RI/CR) when used with deproteinised and etc... The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin(RI/CR) when used with deproteinised and etched occlusal subsurface lesions(International Caries Detection and Assessment System code 2). This combined treatment procedure was compared with the exclusive use of flowable composite resin(CR) for fissure sealing. Twenty premolars and 20 molars revealing non-cavitated occlusal carious lesions were randomly divided into two groups and were meticulously cleaned and deproteinised using Na OCl(2%). After etching with HCl(15%), 10 premolar and 10 molar lesions were infiltrated(Icon/DMG; rhodamine B isothiocyanate(RITC)-labelled) followed by fissure sealing(G-?nial Flo/GC; experimental group, RI/CR). In the control group(CR), the carious fissures were only sealed. Specimens were cut perpendicular to the occlusal surface and through the area of the highest demineralisation(DIAGNOdent pen, Ka Vo). Using confocal laser-scanning microscopy, the specimens were assessed with regard to the percentage of caries infiltration, marginal adaption and internal integrity. Within the CR group, the carious lesions were not infiltrated. Both premolar(57.9% ± 23.1%) and molar lesions(35.3% ± 22.1%) of the RI/CR group were uniformly infiltrated to a substantial extent, albeit with significant differences(P = 0.034). Moreover, microleakage(n = 1) and the occurrence of voids(n = 2) were reduced in the RI/CR group compared with the CR group(5 and 17 specimens,respectively). The RI/CR approach increases the initial quality of fissure sealing and is recommended for the clinical control of occlusal caries. 展开更多
关键词 aprismatic enamel fissure sealing occlusal caries resin infiltration sodium hypochlorite
下载PDF
Identifying the best therapy for chronic anal fissure 被引量:6
16
作者 Mariusz H Madalinski 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 CAS 2011年第2期9-16,共8页
Chronic anal fissure(CAF)is a painful tear or crack which occurs in the anoderm.The optimal algorithm of therapy for CAF is still debated.Lateral internal sphincterotomy(LIS)is a surgical treatment,considered as the&#... Chronic anal fissure(CAF)is a painful tear or crack which occurs in the anoderm.The optimal algorithm of therapy for CAF is still debated.Lateral internal sphincterotomy(LIS)is a surgical treatment,considered as the'gold standard'therapy for CAF.It relieves CAF symptoms with a high rate of healing.Chemical sphincterotomy(CS)with nitrates,calcium blockers or botulinum toxin(BTX)is safe,with the rapid relief of pain,mild sideeffects and no risk of surgery or anesthesia,but is a statistically less effective therapy for CAF than LIS.This article considers if aggressive treatment should only be offered to patients who fail pharmacological sphincterotomy.Aspects of anal fissure etiology,epidemiology and pathophysiology are considered with their meaning for further management of CAF.A molecular model of chemical interdependence significant for the chemistry of CAF healing is examined.Its application may influence the development of optimal therapy for CAF.BTX is currently considered the most effective type of CS and discussion in this article scrutinizes this method specifically.Although the effectiveness of BTXvs LIS has been discussed,the essential focus of the article concerns identifying the best therapy application for anal fissure.Elements are presented which may help us to predict CAF healing.They provide rationale for the expansion of the CAF therapy algorithm.Ethical and economic factors are also considered in brief.As long as the patient is willing to accept the potential risk of fecal incontinence,we have grounds for the'gold standard'(LIS)as the first-line treatment for CAF.The author concludes that,when the diagnosis of the anal fissure is established,CS should be considered for both ethical and economic reasons.He is convinced that a greater understanding and recognition of benign anal disorders by the GP and a proactive involvement at the point of initial diagnosis would facilitate the consideration of CS at an earlier,more practical stage with improved outcomes for the patient. 展开更多
关键词 ANAL fissure BENIGN ANAL diseases Chemical SPHINCTEROTOMY BOTULINUM TOXIN Lateral internal SPHINCTEROTOMY fissurectomy Ethics Teaching
下载PDF
Innovations in chronic anal fissure treatment:A systematic review 被引量:3
17
作者 Aaron Poh Kok-Yang Tan Francis Seow-Choen 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2010年第7期231-241,共11页
A chronic anal fissure is a common perianal condition.This review aims to evaluate both existing and new therapies in the treatment of chronic fissures.Pharmacological therapies such as glyceryl trinitrate(GTN),Diltia... A chronic anal fissure is a common perianal condition.This review aims to evaluate both existing and new therapies in the treatment of chronic fissures.Pharmacological therapies such as glyceryl trinitrate(GTN),Diltiazem ointment and Botulinum toxin provide a relatively non-invasive option,but with higher recurrence rates.Lateral sphincterotomy remains the gold standard for treatment.Anal dilatation has no role in treatment.New therapies include perineal support devices,Gonyautoxin injection,fissurectomy,fissurotomy,sphincterolysis,and flap procedures.Further research is required comparing these new therapies with existing established therapies.This paper recommends initial pharmacological therapy with GTN or Diltiazem ointment with Botulinum toxin as a possible second line pharmacological therapy.Perineal support may offer a new dimension in improving healing rates.Lateral sphincterotomy should be offered if pharmacological therapy fails.New therapies are not suitable as first line treatments,though they can be considered if conventional treatment fails. 展开更多
关键词 Anal fissure Innovative therapy Glyceryl trinitrate Lateral SPHINCTEROTOMY DILTIAZEM BOTULINUM TOXIN PERINEAL support device
下载PDF
Research on ground fissure origins and mechanisms in Hebei Plain,P.R.China 被引量:4
18
作者 QI Jian-feng TIAN Meng-ke +1 位作者 CHI Xiu-cheng WANG Cheng-zhen 《Journal of Groundwater Science and Engineering》 2016年第3期188-196,共9页
Ground fissure hazards frequently emerge in Hebei Plain, which damage roads, dams, buildings and farmland. The paper reviews and analyses current state of knowledge and research into ground fissure and geological envi... Ground fissure hazards frequently emerge in Hebei Plain, which damage roads, dams, buildings and farmland. The paper reviews and analyses current state of knowledge and research into ground fissure and geological environment in Hebei Plain. It is shown that the level of research and investigation is in some aspects insufficient. Knowledge is lacking in the use of corresponding geological concept models for specific ground fissures, three-dimensional numerical simulations of ground fissures caused by pumping through soil with pre-existing fractures, numerical simulations of ground fissures caused by dislocation in intersection faults, and the failure criterion and the constitutive relationship of rock and soil. Furthermore, we put forward geological concept models for ground fissure formation following the dislocation of a buried intersection fault, over-exploitation of groundwater and its compound origin mechanisms in order to provide scientific evidence for the quantitative analysis. 展开更多
关键词 Hebei Plain Ground fissures Formation mechanisms Numerical simulation Problem analysis
下载PDF
Numerical simulation and damage analysis of fissure field evolution law in a single coal seam mining 被引量:1
19
作者 Feng Gao Xingguang Liu +1 位作者 Chaofeng Ge Hongmei Cheng 《International Journal of Mining Science and Technology》 SCIE EI 2012年第6期853-856,共4页
Based on the different deformation and failure laws of coal and rock materials under tensile or compressive loads,the damage variable was defined to divide three phases from the damage and rupture point of view in ord... Based on the different deformation and failure laws of coal and rock materials under tensile or compressive loads,the damage variable was defined to divide three phases from the damage and rupture point of view in order to reveal the fissured field evolution characteristics and spatial distribution of coal and rock in the single coal seam mining with low permeability and rich methane.According to the corresponding damage constitutive equations,the secondary development of the finite element program was completed.The fissures field evolution law of a coal mine with single coal seam mining was calculated and analyzed by this new program and the distribution areas and failure degree of the surrounding coal and rock structures with damage,fissure or rupture are given on the condition of mining.This paper provides a scientific basis for quantitative research and evaluation of the safe simultaneous production of coal and gas. 展开更多
关键词 Single COAL SEAM DAMAGE fissure RUPTURE FINITE element
下载PDF
Quality of compounded topical 2% diltiazem hydrochloride formulations for anal fissure 被引量:1
20
作者 Monil Shah Laura Sandler +2 位作者 Vishwas Rai Charu Sharma Lakshmi Raghavan 《World Journal of Gastroenterology》 SCIE CAS 2013年第34期5645-5650,共6页
AIM:To investigate the quality of topical 2%diltiazem formulations extemporaneously compounded by retail pharmacies openly offering drug-compounding services.METHODS:A participating healthcare professional wrote 12 pr... AIM:To investigate the quality of topical 2%diltiazem formulations extemporaneously compounded by retail pharmacies openly offering drug-compounding services.METHODS:A participating healthcare professional wrote 12 prescriptions for compounded 2%diltiazem cream,with 2 refills allowed per prescription.The 12sets of prescriptions were filled,at intervals of 1-2 wk between refills,at 12 different independent retail pharmacies that openly offer drug-compounding services in a major metropolitan region.The 36 resultant preparations,provided as jars or tubes,were shipped,as soon as each was filled,at ambient temperature to the study core laboratory for high-performance liquid chromatography(HPLC)analysis,within 10 d of receipt.For the HPLC analysis,8 different samples of the topical diltiazem,each approximately 1 g in weight,were taken from prespecified locations within each container.To initiate the HPLC analysis,each sample was transferredto a 100 mL volumetric flask,to which methanol was added.The HPLC analysis was conducted in accordance with the laboratory-validated method for diltiazem in cream,ointment,and gel formulations.The main outcome measures were potency(percentage of label claim)and content uniformity of the compounded topical 2%diltiazem formulations.RESULTS:Of the 36 prescriptions filled,30 were packaged in jars and 6 were packaged as tubes.The prescriptions were specifically for cream formulations,but6 of the 12 pharmacies compounded 2%diltiazem as an ointment;for another pharmacy,which had inadequate labeling,the dosage form was unknown.The United States Pharmacopoeia(USP)standard for potency is 90%-115%of label claim.Of the 36 preparations,5(13.89%)were suprapotent and 13(36.11%)were subpotent.The suprapotent prescriptions ranged in potency from 117.2%to 128.5%of label claim,and the subpotent prescriptions ranged in potency from34.8%to 89.8%of label claim.Fourteen(38.9%)preparations lacked content uniformity according to the USP standard of 90%-110%potency and<6%relative standard deviation.Of the 30 formulations packaged in jars,12(40%)lacked content uniformity,while of the6 formulations packaged in tubes,2(33.3%)lacked content uniformity.Nine of the 12 pharmacies(75%)failed USP potency or content-uniformity specifications for at least 1 of the 3 prescription fills.For 5 of the 12pharmacies(41.7%),the mean potency across all three prescription fills was<90%of label claim.CONCLUSION:Patients prescribed topical 2%diltiazem for treatment of anal fissure frequently receive compounded formulations that are misbranded with respect to potency and that lack content uniformity. 展开更多
关键词 Anal fissure PHARMACY COMPOUNDING TOPICAL DILTIAZEM Formulation POTENCY Content uniformity
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部