scholarly journals Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 564
Author(s):  
Vladimir Čebašek ◽  
Veljko Rupar ◽  
Stevan Đenadić ◽  
Filip Miletić
Keyword(s):  
Coal Mining ◽  
Laboratory Testing ◽  
Water Pressure ◽  
Laboratory Data ◽  
Working Environment ◽  
Laboratory Research ◽  
Surrounding Water ◽  
Cutting Resistance ◽  
Testing Methodology

The bucket-wheel dredge “Kovin I” for underwater coal mining with bucket-wheel type UCW-450 has been in operation for over 20 years. Based on analyzing the bucket-wheel dredger performance, productivity, maintenance costs, and reliability, a rational decision was made: to rehabilitate the most essential parts of the dredge, including the bucket wheel and the gearbox. However, the selection and construction of the excavator parts were performed on the ground of available laboratory data for digging resistance. The data itself was determined by the testing methodology that did not include the influence of surrounding water pressure at a certain depth of mining. According to the previous findings, it was necessary to develop a specific research and testing program that would involve appropriate laboratory testing of the geomechanical parameters. These were to represent the influence of hydrostatic water pressure on the working environment—coal. Nevertheless, geomechanical laboratory research tests were initially modified to provide reliable data of cutting resistance, especially in the water under different hydrostatic pressures, fully simulating the “in situ” working conditions of mining, i.e., cutting.

Mathematical Model Investigation of Far-Field Transport of Ocean-Dumped Sewage Sludge Related to Remote Sensing

1982 ◽  
Vol 14 (3) ◽  
pp. 33-39
Author(s):  
C Y Kuo
Keyword(s):  
New York ◽  
Sewage Sludge ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Approximate Model ◽  
Transport Processes ◽  
Far Field ◽  
New York Bight ◽  
Mean Current

An existing, three-dimensional, Eulerian-Lagrangian finite-difference model was modified and used to examine the far-field transport processes of dumped sewage sludge in the New York Bight. Both in situ and laboratory data were utilized in an attempt to approximate model inputs such as mean current speed, vertical and horizontal diffusion coefficients, particle size distributions, and specific gravities. Concentrations of the sludge near the sea surface predicted from the computer model were compared qualitatively with those remotely sensed.

Laboratory Testing for HER2/neu in Breast Carcinoma: An Evolving Strategy to Predict Response to Targeted Therapy

2001 ◽  
Vol 8 (5) ◽  
pp. 415-418 ◽  
Author(s):  
Nils M. Diaz
Keyword(s):  
Targeted Therapy ◽  
Breast Carcinoma ◽  
Gene Amplification ◽  
Laboratory Testing ◽  
False Positives ◽  
Response To Therapy ◽  
Fish Analysis ◽  
Breast Carcinomas ◽  
Testing Strategies

Background Laboratory testing of HER2/neu in breast carcinoma has become vital to patient care following the approval of trastuzumab as the first therapy to target the HER2/neu oncoprotein. Initial clinical trials used immunohistochemistry (IHC) to test for HER2/neu overexpression in order to select patients for therapy. Fluorescence in situ hybridization (FISH), which tests for gene amplification, is more specific and sensitive than IHC when either assay is compared with HER2/neu overexpression as determined by Northern or Western blot analysis. Many weak overexpressors on IHC testing are not gene amplified on FISH analysis. Such weak overexpressors may be considered false-positives and raise the question of how best to test for HER2/neu. Methods The literature was surveyed regarding testing for HER2/neu overexpression in breast carcinomas and alternative testing strategies. Results False-positive results are a significant problem when IHC is exclusively used to test for HER2/neu overexpression. The false-positives are overwhelmingly confined to the group of 2+ positives and do not respond to targeted therapy. In contrast, concordance between IHC and FISH is high when immunostaining is interpreted as either negative or strongly positive (3+). Whereas some recent studies have suggested that FISH may better predict response to anti-HER2/neu therapy than IHC, others have indicated that IHC is as effective a predictor as FISH. IHC is less technically demanding and costly than FISH. Conclusions IHC analysis of HER2/neu in breast carcinoma is a useful predictor of response to therapy with trastuzumab when strongly positive. Negative immunostaining is highly concordant with a lack of gene amplification by FISH. Most weakly positive overexpressors are false-positives on testing with FISH. Thus, screening of breast carcinomas with IHC and confirmation of weakly positive IHC results by FISH is an effective evolving strategy for testing HER2/neu as a predictor of response to targeted therapy.

Research on Intelligent Control of the Dust in Coal Mining

2012 ◽  
Vol 482-484 ◽  
pp. 1805-1808
Author(s):  
Zhao Ran Zhang ◽  
Guo Qing Liu ◽  
Xiao Sheng Bai ◽  
Guo Liang Yang
Keyword(s):  
Coal Mining ◽  
Intelligent Control ◽  
Coal Dust ◽  
Working Environment ◽  
Coal Face ◽  
Good Working ◽  
Mining Coal ◽  
Good Working Environment

The harm of coal dust under mining coal is really serious, so how to effectively control it has always been a tough problem. This paper analyzes the cause of creating dust over the coal face, and introduces the application of dust intelligent control in detail based on the reality situation of coal mining. Though the application of intelligent dustproof system, the concentration of the coal dust has been reduced by 333.9mg/m3 to 21.7mg/m3, the result is creating a good working environment for workers, this system has the higher valuable application.

The Test Study to the Changes of Excess Pore Water Pressure during Precast Pile Construction

2012 ◽  
Vol 193-194 ◽  
pp. 1010-1013
Author(s):  
Shu Qing Zhao
Keyword(s):  
Pore Water ◽  
Clayey Soil ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Excess Pore Pressure ◽  
Soil Pressure ◽  
Excess Pore Water Pressure ◽  
Test Study ◽  
Excess Pore

The construct to precast pile in thick clayey soil can cause the accumulation of excess pore water pressure. The high excess pore pressure can make soil, buildings and pipes surrounded have large deflection, even make them injured. Combining with actual projects, this paper presents an in-situ model test on the changes of excess pore water pressure caused by precast pile construct. It is found that the radius of influence range for single pile driven is about 15m，the excess pore water pressure can reach or even exceed the above effective soil pressure, and there are two relatively stable stages.

Principle of Well-Net Design for Coalbed Methane Exploitation in Coal Mine Area

2014 ◽  
Vol 543-547 ◽  
pp. 3967-3973
Author(s):  
Bao Shan Han
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
Coalbed Methane ◽  
Design Theory ◽  
Surface Condition ◽  
Coal Pillar ◽  
Negative Influence ◽  
In Situ Stress ◽  
Well Location

There are abundant CBM (Coalbed Methane) in China. These CBM has caused a remarkable problem to the coal-mining in China. In order to improve the structure of Chinese energy and eliminate the risk of coal mine gas, the relevant industries and sections have implemented many explorations in CBM enriched areas. With great achievements, there are many important problems in the actions of CBM exploitation. The disadvantageous interaction of the surface CBM well and the later coal mining has been ignored at all. There are many disadvantages and defects. To solve these problems and eliminate or weaken the disadvantageous, the scientific and reasonable design of surface CBM well location is an important step. With the thinking of surface condition, coal mining plan, the arrangement of coal mine laneway, the direction and scale of the in-situ stress, and thinking more about the negative influence to and of surface CBM well, according to the theories of mining dynamics, mining engineering, mining geomechanics, and the CBM engineering, the design theory of the surface CBM well net can be studied. Finally, the arrangement principle of CBM product well in coal field is presented. The existing or future coal pillar will be a critical location for the surface CBM well location.

Assessment of Moisture Content in Sandy Beach Environments from Multispectral Satellite Imagery

2021 ◽  
Author(s):  
Julie Paprocki ◽  
Nina Stark ◽  
Hans C Graber ◽  
Heidi Wadman ◽  
Jesse E McNinch
Keyword(s):  
Moisture Content ◽  
Laboratory Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sandy Beaches ◽  
Percent Error ◽  
Moisture Contents ◽  
Multispectral Satellite Imagery ◽  
Factor C

A framework for estimating moisture content from satellite-based multispectral imagery of sandy beaches was tested under various site conditions and sensors. It utilizes the reflectance of dry soil and an empirical factor c relating reflectance and moisture content for specific sediment. Here, c was derived two ways: first, from in-situ measurements of moisture content and average NIR image reflectance; and second, from laboratory-based measurements of moisture content and spectrometer reflectance. The proposed method was tested at four sandy beaches: Duck, North Carolina, and Cannon Beach, Ocean Cape, and Point Carrew, Yakutat, Alaska. Both measured and estimated moisture content profiles were impacted by site geomorphology. For profiles with uniform slopes, moisture contents ranged from 3.0%-8.0% (Zone 1) and from 8.0%-23.0% (Zone 2). Compared to field measurements, the moisture contents estimated using c calibrated from in-situ and laboratory data resulted in percent error of 3.6%-44.7% and 2.7%-58.6%, respectively. The highest percent error occurred at the transition from Zone 1 to Zone 2. Generally, moisture contents were overestimated in Zone 1 and underestimated in Zone 2, but followed the expected trends based on field measurements. When estimated moisture contents in Zone 1 exceeded 10%, surface roughness, debris, geomorphology, and weather conditions were considered.

Developing an in situ, hydromechanical coupling, true triaxial rock compression tester and investigating the deformation patterns of reservoir bank slopes

2021 ◽  
pp. qjegh2021-043
Author(s):  
Lei Fan ◽  
Meiwan Yu ◽  
Aiqing Wu ◽  
Yihu Zhang
Keyword(s):  
Coupling Effect ◽  
Water Pressure ◽  
Pressure Coefficient ◽  
Hydromechanical Coupling ◽  
Rock Interaction ◽  
True Triaxial ◽  
Rock Structure ◽  
Deformation Patterns

Interactions between water and rocks are the main factors affecting the deformation of rock masses on sloped banks by reservoir impoundment. The technology used in laboratory tests of water-rock interaction mechanisms cannot simulate the coupling of water, the rock structure and the initial stress environment. In this work, we develop an in situ hydromechanical true triaxial rock compression tester and apply it to investigate the coupling response of reservoir bank rocks to changing groundwater levels. The tester is composed of a sealed chamber, loader, reactor, and device for measuring deformation, which are all capable of withstanding high water pressures, and a high-precision servo controller. The maximum axial load, lateral load and water pressure are 12 000 kN, 3 000 kN and 3 MPa, respectively. The dimensions of the test specimens are 310 mm×310 mm×620 mm. The test specimens are grey-black basalts with well-developed cracks from the Xiluodu reservoir area. The results show that increasing water pressure promotes axial compression and lateral expansion, while decreasing water pressure causes axial expansion and lateral compression. A water pressure coefficient, K, is introduced as a measure of the hydromechanical coupling effect (expansion or compression) with changing groundwater level. A mechanical tester can be used to perform accurate field tests of the response of wet rocks to hydromechanical coupling. The test results provide new information about the deformation patterns of rock slopes in areas surrounding high dams and reservoirs.Thematic collection: This article is part of the Role of water in destabilizing slopes collection available at: https://www.lyellcollection.org/cc/Role-of-water-in-destabilizing-slopes

scholarly journals Bioconcentration of glyphosate in wetland biofilms

2020 ◽  
Author(s):  
Laura Beecraft ◽  
Rebecca Rooney
Keyword(s):  
Trophic Levels ◽  
Breakdown Product ◽  
Exposure Risk ◽  
Surrounding Water ◽  
Wetland Water ◽  
Pesticides Exposure ◽  
Wetland Water Quality ◽  
Herbicide Glyphosate

AbstractWetland biofilms were exposed to the herbicide glyphosate via in situ field exposures and controlled microcosm experiments to measure bioconcentration and metabolism of glyphosate by biofilm organisms. Glyphosate concentrations in biofilms were orders of magnitude higher than the surrounding water, bioconcentration factors averaged 835 and 199 in field- and lab-exposed biofilms, respectively. Glyphosate in water where it had been detected in biofilms at field-exposed sites ranged from below detection (<0.001 ppm) up to 0.13 ppm. Glyphosate bioconcentration in biofilms was inversely proportional to levels in the surrounding water, and the retention kinetics were similar to both adsorption and enzymatic models. Microorganisms present in both the water and biofilms metabolized glyphosate to its primary breakdown product aminomethyl phosphonic acid (AMPA), with increased rates of breakdown in and around the biofilms. Photosynthetic efficiency of the algae within the biofilms was not affected by 24 h glyphosate controlled exposures. Our results demonstrate the role of biofilms in improving wetland water quality by removing contaminants like glyphosate, but also as a potential exposure route to higher trophic levels via consumption. Due to bioconcentration of pesticides, exposure risk to organisms consuming or living in biofilms may be much higher than indicated by concentrations in ambient water samples.

scholarly journals Analisis Numerik Pengaruh Infiltrasi Hujan Terhadap Stabilitas Lereng Di Pangkalan, Sumatera Barat

2020 ◽  
Vol 11 (1) ◽  
pp. 25-36
Author(s):  
Rokhmat Hidayat
Keyword(s):  
Slope Stability ◽  
Hydrological Modeling ◽  
Water Pressure ◽  
Laboratory Data ◽  
Soil Layer ◽  
Infiltration Process ◽  
The Road ◽  
Horizontal Drain ◽  
Landslide Event ◽  
Rain Infiltration

The landslides event was triggered by rain infiltration is an annual occurrence in Indonesia, majority of landslide occur in rainy season. In this research, the case of landslide taken in Pangkalan Area, District of Limapuluh Kota, West Sumatera. The location of the case study is the main access of West Sumatra-Riau, so the landslide in the location is certainly causing close the road. Research phase is geology mapping, geotechnical analysis, and hydrological modeling. Hydrological modeling is done by numerical simulation using laboratory data. The modeling results show that the rain infiltration process resulted in the formation of positive water pressure zone at the foot of the slope, then spread towards the top of the slope.  One day after the rainfall, the soil layer had been saturated. The soil layer will saturate the water, so that the slope stability will decrease and the landslide event will occur. To improve the slope stability, it can be done by preventing water from entering the permeable layer with the installation of the shotcrete layer, and draining the water from the slopes by the installation of horizontal drain.

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