Test Method and Application of Broken Rock Zone of Roadway Surrounding Rock by Borehole Imaging

2012 ◽  
Vol 524-527 ◽  
pp. 1213-1216 ◽  
Author(s):  
Yong Jie Yang ◽  
Min Wang ◽  
Kai Wang
Keyword(s):  
Coal Mine ◽  
Reference Value ◽  
Test Methods ◽  
Surrounding Rock ◽  
Test Method ◽  
Imaging Method ◽  
Actual Situation ◽  
Test Results ◽  
Coal Face ◽  
Borehole Imaging

It is of great significance to select the reasonable support pattern and support parameters for accurately determining the magnitude of the broken rock zone of roadway. At present, the test methods of the broken rock zone of the roadway surrounding rock all have stated disfigurements and deficiency. The borehole imaging method has advantages: simple operation and the test results being intuitive and reliable. The test results and analysis of the broken rock zone of rail crossheading in 3down 109 coal face of Luxi Coal Mine show that the test results consistent well with the actual situation and they have practical reference value for the test and application of the broken rock zone of the roadway surrounding rock.

Experimental Research on Vibration Characteristics of Laminated Composite Cantilever Beam

2021 ◽  
Author(s):  
Rui Yang ◽  
Xiaobin Li ◽  
Hongxi Li
Keyword(s):  
Cantilever Beam ◽  
Optical Measurement ◽  
Laminated Composite ◽  
Experimental Methods ◽  
Test Methods ◽  
Vibration Characteristics ◽  
Test Method ◽  
Vibration Measurement ◽  
Vibration Test ◽  
Test Results

Abstract In this paper, the vibration characteristics of laminated composite cantilever beam is taken as the research object. Firstly, a vibration formula specific for laminated composite cantilever beam is derived, from which the low order natural frequency of laminated composite cantilever beam is calculated; Secondly, two experimental methods, electrical and optical measurement, are used to study the vibration characteristics of laminated composite cantilever beam, and the influence of different test methods, sensor types, number of measuring points and excitation methods on the test results are analyzed. Through the combination of theory and experiment, a test method that can be applied to the vibration test of composite material laminated structure cantilever beam is obtained. Based on the laser vibration measurement method in the optical method, the results show that the deviation between the experimental data and the theoretical solution is the smallest when the distance between the probe and the specimen is 0.5m and the sampling time is 5s by using the optical fiber vibrometer. The research content of this article can provide a reasonable reference for related vibration test research.

Methods to Evaluate Cleaners and Sanitizers

1982 ◽  
Vol 45 (13) ◽  
pp. 1257-1260 ◽  
Author(s):  
DALE L. SCHEUSNER
Keyword(s):  
Test Methods ◽  
Test Method ◽  
Test Results ◽  
Standard Laboratory ◽  
Test Procedures ◽  
Laboratory Methods ◽  
Product Use ◽  
Cellulose Sponge ◽  
Equivalent Test ◽  
Recovery Methods

Methods to evaluate germicides can be grouped into three categories: standard laboratory tests, in-use tests and simulated-use tests. Standard laboratory methods, such as the Available Chlorine Germicidal Equivalent test, are specifically defined for reproducibility in any laboratory by any operator, but the test results often lack relevance to actual product-use conditions. In-use test methods are relevant to product-use; however, in-use test procedures do not permit proper controls to be included in the organism recovery methods. Contact plates give an estimate of organism numbers which is only 25% of the theoretical number of organisms present. Organism recovery using a swab, cellulose sponge or tube sampler give estimates of organisms ranging from 91 to 111% of theoretical. The tube sampler is a 1-in. length of flexible tubing having a 1-in. interior diameter and a smooth end, which can make a water-tight seal on a flat surface. Simulated use testing yields data which are relevant to actual product-use. A cafeteria tray is soiled, inoculated and cleaned in a manner to simulate actual product-use. This test method permits the necessary controls to be used. Tray-test reproducibility is as good as that of the other recovery methods tested and organism recovery is quantitative. The tray test provides a means for determining biological cleaning where the effect of both cleaning and germicidal activity are measured together.

scholarly journals Support design of main retracement passage in fully mechanised coal mining face based on numerical simulation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yalong Li ◽  
Mohanad Ahmed Almalki ◽  
Cheng Li
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Control Measures ◽  
Coal Face ◽  
Support Design ◽  
Working Face ◽  
Surrounding Rock Control ◽  
Mining Face ◽  
Mining Pressure

Abstract For the comprehensive mechanised coal mining technology, the support design of the main withdrawal passage in the working face is an important link to achieve high yield and efficiency. Due to the impact of mining, the roof movement of the withdrawal passage is obvious, the displacement of the coal body will increase significantly, and it is easy to cause roof caving and serious lamination problems, and even lead to collapse accidents, which will affect the normal production of the mine. In this paper, the mining pressure development law of the main withdrawal passage support under the influence of dynamic pressure is designed, the most favourable roof failure form of the withdrawal passage is determined, and the action mechanism and applicable conditions of different mining pressure control measures are studied. The pressure appearance and stress distribution in the final mining stage of fully mechanised coal face are studied by numerical simulation. The deformation and failure characteristics and control measures of roof overburden in the last mining stage of fully mechanised coal face are analysed theoretically. Due to the fact that periodic pressure should be avoided as far as possible after the full-mechanised mining face is connected with the retracement passage, some auxiliary measures such as mining height control and forced roof blasting are put forward on this basis. The relative parameters of the main supporting forms are calculated. The main retracement of a fully mechanised working face in a coal mine channel is put forward to spread the surrounding rock grouting reinforcement, reinforcing roof, and help support and improve the bolt anchoring force, the main design retracement retracement channels in the channel near the return air along the trough for supporting reinforcing surrounding rock control optimisation measures, such as through the numerical simulation analysis, the optimisation measures for coal mine fully mechanised working face of surrounding rock is feasible. Numerical simulation results also show that the surrounding rock control of fully mechanised working face of coal mine design improvements, its main retreat channel under the roof subsidence, cribbing shrank significantly lower, and closer, to better control the deformation of surrounding rock, achieved significant effect, to ensure the safety of coal mine main retracement channel of fully mechanised working face support.

scholarly journals Performance characteristics of polymerase chain reaction and histological methods for the detection of Haplosporidium nelsoni in the eastern oyster (Crassostrea virginica)

2015 ◽  
Vol 27 (4) ◽  
pp. 476-488 ◽  
Author(s):  
Nellie Gagné ◽  
Anne Veniot ◽  
Mary Stephenson ◽  
Carol McClure
Keyword(s):  
Polymerase Chain Reaction ◽  
Test Methods ◽  
Test Method ◽  
Performance Characteristics ◽  
Analytical Sensitivity ◽  
Test Results ◽  
Fitness For Purpose ◽  
Chain Reaction ◽  
Repeatability And Reproducibility ◽  
Polymerase Chain

Fitness for purpose and validation are increasingly becoming a benchmark in the development of test methods for the diagnosis of infectious diseases in aquatic animals. The design of the evaluation and the analysis of data are critical to demonstrate test method performance characteristics and fitness for purpose, as stated in the World Organization for Animal Health pathway for test validation. Three test methods for the detection of the oyster parasite Haplosporidium nelsoni were selected for the validation study described herein: histology, end-point polymerase chain reaction (PCR), and real-time PCR (qPCR). Preliminary work evaluated the analytical sensitivity and specificity of the PCR and qPCR assay in development. The following stage used test results on 100 oysters in 3 different laboratories to assess diagnostic sensitivity (DSe), diagnostic specificity (DSp), repeatability, and reproducibility. Repeatability and reproducibility were within 68–95%. The final part of the project evaluated DSe and DSp using test results on 400 oysters and results from the first 100 oysters tested. In the absence of a 100% gold standard test, latent class modeling methods were explored to characterize the tests (i.e., Bayesian analyses). For both PCR methods, DSe was >90%, and in the 60% range for histology, whereas DSp was >90% for all methods. Based on the results of this validation, a threshold cycle value of 30 for qPCR corresponds to the limit of sensitivity for histology where unreliable detection becomes more frequent, thus providing a threshold helpful in diagnostic settings where both histology and qPCR are used.

The Research of Negative Ion Test Method for Fabric

2013 ◽  
Vol 756-759 ◽  
pp. 138-140 ◽  
Author(s):  
Yun Sen Sun ◽  
Bo Qiu ◽  
Qing Shan Li
Keyword(s):  
Influence Factors ◽  
Test Methods ◽  
Test Method ◽  
Ion Concentration ◽  
Negative Ion ◽  
Testing Device ◽  
Test Results ◽  
Influence Of Temperature ◽  
Functional Textiles ◽  
Temperature And Humidity

We developed a device for automatic closed friction and analyzed its test results in this paper, which showed the influence factors in the test methods of textile negative ion occurrence amounts. The textile negative ion occurrence amounts in different time stages were tested in this process; the analysis of its influence of temperature and humidity has certain reference significance for improving testing device for testing textile negative ion concentration, on the basis, functional textiles were also studied. Finally, we put forward the influence factors in the test methods of textile negative ion occurrence amounts.

Transient Methods of Thermal Properties Measurement on Fibrous Materials

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Zuo Lei ◽  
Sukang Zhu ◽  
Ning Pan
Keyword(s):  
Fibrous Material ◽  
Local Heat ◽  
Test Methods ◽  
Test Method ◽  
Dual Phase ◽  
Fibrous Materials ◽  
Test Results ◽  
Main Factors ◽  
Transient Methods ◽  
Transfer Properties

Fibrous material is a complex porous medium and steady test methods are the main test approaches we currently depend on to study the heat transfer properties. The application of unsteady test methods on fibrous material is still not mature. In this paper, some systematic studies are taken to investigate this problem. By analyzing the main factors impacting the test results, it is found that the local heat convection potentially excited by imposing test temperature can be avoided by limiting the internal temperature gradient and the so-called dual-phase lagging effects are negligible so that the feasibility of the unsteady test method is verified via both theoretical analysis and experimental data.

scholarly journals THE ESTIMATION PROBLEMS OF THE FIRE HAZARD FOR VERTICALLY ORIENTED BUILDING PRODUCTS/VERTIKALIAI ORIENTUOTŲ STATYBINIŲ GAMINIŲ GAISRINIO PAVOJINGUMO ĮVERTINIMO PROBLEMOS

1999 ◽  
Vol 5 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Albertas Nyderis
Keyword(s):  
Heat Transfer ◽  
Fire Protection ◽  
Fire Test ◽  
Test Methods ◽  
Test Method ◽  
Building Construction ◽  
Research Centre ◽  
Test Results ◽  
Solid Materials ◽  
Building Products

The Directive of new approach 89/106/EEC, which was prepared by Directorate General of the European Commission (DG III), defines the guidelines for development of fire protection in building construction. Six main directions for development of fire protection are defined in this Directive as well. Solid materials are most numerous among building products. Therefore a brief analysis of combustion process of these materials is presented in this article. F.Williams developed the theoretical principles of combustion. Phase transitions in the zone of combustion are analyzed in the theory. Formulas 1–4 describe this process. The process of combustion of solid materials is heterogeneous; therefore the model of pyrolysis is presented by 5 formulas. An intricate energy exchange takes place in real fires. The heat is being transferred in different ways. The most acceptable description of heat transfer is by means of radiation. Description of this process is presented in formulas 6–7. The heat transfer by means of radiation can be modelled and used for environment testing. The combustibility of building products can be examined by means of reaction of fire tests. In recent years tests for different building products were carried out according to ISO 5657 test methodology in the Fire Research Centre. Test results indicate that the time to sustained surface ignition for building products is inversely proportional to heat flux. This logarithmic dependence is presented in 8 formulas. Establishment of parameters of this logarithmic flow for different building products can prove this. This work was carried out during the process of verification of this hypothesis. Analysis of fire testing practice of vertically oriented building products in different countries shows that harmonized fire test methods for these products do not exist. Most of these test methods are based on presumption that the flame spread is possible only inside the building not considering the behaviour of facade in fire. The main idea of fire test method for element of vertically oriented building construction together with the principal scheme of test equipment are presented in the article as well. Further development of this idea leads to five questions, which should be answered to solve the problem. After the completion of this task and analysis of test results, all the information is to be submitted for further consideration.

scholarly journals Fracturing of the Soft Rock Surrounding a Roadway Subjected to Mining at Kouzidong Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Zhili Su ◽  
Wenbing Xie ◽  
Shengguo Jing ◽  
Xingkai Wang ◽  
Qingteng Tang
Keyword(s):  
Failure Mechanism ◽  
Coal Mine ◽  
Shear Failure ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Asymmetric Distribution ◽  
Rock Layer ◽  
Imaging Results ◽  
Fracture Development ◽  
Borehole Imaging

The fracture development and distribution around the deep soft rock roadway are pivotal to any underground design. In this paper, both field investigation and numerical simulation were taken to study the fracture evolution and rock deformation of a coal mine roadway at Kouzidong mine, Fuyang, Anhui Province, China. Based on the borehole imaging technique, we found an asymmetric distribution of the fracture zone in the surrounding rock of the roadway. By analyzing the C value of the fractures in the borehole images,we found that the fracture interval distribution of the surrounding rock of the tunnel, the number of fractures will fluctuate decrease with the increase of the depth. To effectively study the fracture propagation and distribution of the roadway under longwall retreatment and roadway excavation, the global-local numerical technique was applied via FLAC3D and PFC2D. In the roadway excavation process, fractures were first formed in the shallow section of the roadway and progressively propagated toward the deeper soft rock layer; the main failure mechanism was a tensile failure. During longwall retreatment, fractures continuously developed toward the deeper soft rock layer. However, the failure mechanism transformed to shear failure. From numerical results, it can be seen that the stress concentration at the ribs was released, which led to shear failure at the roof and floor. Due to the extensive tensile cracks in the shallow section, the surrounding rock experienced expansion and fracture. The deep shear failure also induced the formation of the nonadjacent crushing zone and elastic zone, which is in line with the borehole imaging results.

scholarly journals A Flight Test Method of Flammable Liquid Leakage and Discharge for Certain Aircraft

2018 ◽  
Vol 227 ◽  
pp. 01001
Author(s):  
Jiangtao Song ◽  
Yan Zhao ◽  
Yu Li
Keyword(s):  
Flight Test ◽  
Test Methods ◽  
Test Method ◽  
Test Equipment ◽  
Test Results ◽  
Successful Completion ◽  
Flammable Liquid ◽  
Flight Tests ◽  
Civil Aircraft ◽  
Certification Test

To guarantee the successful completion of airworthiness certification test for a certain type of aircraft, the leakage and discharge compliance criteria of flammable liquid were designed by studying airworthiness requirements and the design characteristic of the civil aircraft, where flammable liquid leakage zones and hazardous zones in which liquids are not allowed to enter were determined. Further the test equipments and the dyeing liquor for replacing flammable fluid were developed, and ground and flight test methods were proposed. Moreover, the above test equipment and methods were applied to flight tests of flammable liquid leakage and discharge for certain civil aircraft. The test results show that the test equipment is stable and reliable, and the flight test method can accurately demonstrate the flammable liquid leakage and discharge.

scholarly journals MATERIAL TEST AND RESULTS ESTIMATION BY SAFETY INDEXES

2021 ◽  
Vol 82 (2) ◽  
pp. 38-45
Author(s):  
Mykola Mykyjchuk ◽  
◽  
Y. Rudyk ◽  
Keyword(s):  
Construction Material ◽  
Measurement Techniques ◽  
Fire Retardant ◽  
Test Methods ◽  
Test Method ◽  
Steel Plates ◽  
Test Results ◽  
Material Test ◽  
Advantages And Disadvantages ◽  
Safety Systems

In the article, both the test method features and the test results of research of thermal behavior of steel fragment were analyzed. Two types of test conditions for steel construction material were considered. The definition and main features of measurement techniques were presented. Fire retardant material test results for steel plates with hydrogen combustion shown the limit of fire resistance of the tested samples is more than 30 min. The main advantages and disadvantages of the test were determined. The positive and negative aspects of this approach were analyzed. These techniques' effective thermal condition is in an environment of uncertainty and has no limited resources was established. Concepts and principles for establishing validity, and frameworks and methods for validating test methods and their results are important elements of safety systems. The article considers the safety of the technical component of a complex organizational and technical system with the study of the functional relationship between the safety elements parameters: temperature, time, fire retardant – by hydrogen participation.

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