The Influence of Gas Environment on Coal Properties - Experimental Studies on Outburst Control

The volumetric changes in the coal matrix (Coal Shrinkage) and permeability properties under various gas environment conditions were studied in the laboratory. The shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. The shrinkage tests were carried out in high -pressure bombs while the permeability study was conducted in a specially constructed high pressure chamber. Methane (CH4), carbon dioxide(CO2), nitrogen (N2) and a 50% mixture of CO2/CH4 gas were used in the study. The tests showed that under different pressure levels gas type affected permeability and shrinkage characteristics of coal

Sensitive high-resolution melting analysis for screening of kras and braf mutations in Iranian human metastatic colorectal cancers

Background: Investigations of methods for detection of mutations have uncovered major weaknesses of direct sequencing and pyrosequencing, with their high costs and low sensitivity in screening for both known and unknown mutations. High resolution melting (HRM) analysis is an alternative tool for the rapid detection of mutations. Here we describe the accuracy of HRM in screening for KRAS and BRAF mutations in metastatic colorectal cancer (mCRCs) samples. Materials and Methods: A total of 1000 mCRC patients in Mehr Hospital, Tehran, Iran, from Feb 2008 to May 2012 were examined for KRAS mutations and 242 of them were selected for further assessment of BRAF mutations by HRM analysis. In order to calculate the sensitivity and specificity, HRM results were checked by pyrosequencing as the golden standard and Dxs Therascreen as a further method. Results: In the total of 1,000 participants, there were 664 (66.4) with wild type and 336 (33.6) with mutant codons 12 and/or 13 of the KRAS gene. Among 242 samples randomly checked for the BRAF gene, all were wild type by HRM. Pyrosequencing and Dxs Therascreen results were in line with those of the HRM. In this regard, the sensitivity and specificity of HRM were evaluated as 100. Conclusion: The findings suggest that the HRM, in comparison with DNA sequencing, is a more appropriate method for precise scanning of KRAS and BRAF mutations. It is also possible to state that HRM may be an attractive technique for the detection of known or unknown somatic mutations in other genes

Correction to: Destructive Roles of Fibroblast-Like Synoviocytes in Chronic Inflammation and Joint Damage in Rheumatoid Arthritis (Inflammation, (2021), 44, 2, (466-479), 10.1007/s10753-020-01371-1)

Following the publication of the original article, the corresponding author noticed that the second corresponding author has not been mentioned. The below statement must be added to the correspondence section: Jafar Karami; Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. E-mail: [email protected]; [email protected] The original article has been corrected. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Application of financial risk analysis for project evaluation at a large coal mine

Today risk analysis is largely employed in studying the uncertainty of financial decisions in new mining ventures. The methodology for examination and quantification of financial risks is investigated in this paper. A coal mining project is generally a long term process. Also, any increase in the project time, raises the probability of variation in effective financial parameters. Therefore, the forecasting and risk analysis for this kind of projects will be more important. For this reason, this work has been prepared for the purpose of presenting the methodology and uses of techniques applied in the evaluation of the long term projects to analyse and assess risk. The flexibility of spreadsheets and their statistical capabilities make them a common framework for simulation modelling. In this paper, the discussion is illustrated with an example of stochastic discounted cash flow for a real large coal mine. Then, Excel spreadsheet tools for the simulation, and also a powerful risk analysis software have been used. Finally, the paper examines output data from analysis of mentioned project

Status of Outburst Research at the University of Wollongong

There has been an ongoing research on coal and gas outburst for the past two decades at the School of Civil, Mining and Environmental Engineering, University of Wollongong. Research study began with a humble beginning, initially conducting basic laboratory studies on the coal and gas properties, progressing into the determination of gas content of coal by sorption technique and the effect of gas pressures on coal strength. The present laboratory facilities and research interests are extended to include the study of coal permeability and shrinkage properties and their effect of gas drainage characteristics with respect to gas type, and pressures. All the changes are examined with respect to changing in-site geological conditions of the coal deposit investigated. The aim is to provide a long-term support to industry in establishing a data bank for Australian coal deposit characteristics and properties

Study of Gas Environment Impacts on Volumetric Coal Matrix Changes

The Outburst can be defined as a sudden release of coal and rock accompanied by large quantities of gas into the underground coal mine workings which represents a major hazard in underground coal mines. Gas drainage has been proven to be successful in reducing outburst hazards by decreasing the in-situ gas pressure. One of aspect of gas drainage from coal seams is coal matrix volume changes. Current study is primarily concerned with experimental studies related to coal volume change (coal shrinkage) under various gas types and pressures. Two types of tests were conducted on each sample, the adsorption test for coal swelling and the desorption test for coal shrinkage. The gases used in the study were CH4, CO2, CH4/CO2 (50-50% volume), and N2. In this research, tests were conducted with respect to volumetric change behavior in different gases and their corresponding comparative results were presented

Prognozowanie wydajności pracy strunowej piły diamentowej w odniesieniu do charakterystyki tekstury skał

In this study, prediction of production rate in diamond wire saw has been investigated. Performance measurements of diamond wire saw carried out in 7 different quarries of carbonate rocks in Iran. For determination textural properties, rock samples were collected from these quarries. At first, a thin section was prepared for each rock and then 5 digital photographs were taken from each section. After this, all images were digitized using AutoCAD software. Then, area, perimeter, longest diameter and shortest diameter were assigned. According to these parameters, all of the other textural characteristics and texture coefficient were determined too. The correlation between sawing rate and textural characteristics were evaluated using multiple and simple regression analyses. Then developed model was validated by P-value test. It was concluded that area, perimeter, diameter equivalent and index of grain size homogeneity are very effective on production rate. Production rate using diamond wire saw can reliably be predicted using developed model.W pracy prognozowano wydajność pracy strunowej piły diamentowej. Badania wydajności prowadzono w 7 kamieniołomach na terenie Iranu, w których wydobywane są skały węglanowe. W celu określenia tekstury skał zebrano próbki wszystkich skał wydobywanych w kamieniołomach. Przygotowano zgłady i wykonano 5 fotografii cyfrowych każdej analizowanej próbki. Uzyskane obrazy poddano następnie obróbce cyfrowej przy użyciu oprogramowania AutoCAD. Określono następujące parametry: powierzchnia, obwód, najdłuższa i najkrótsza średnica. W oparciu o powyższe parametry przeprowadzono analizę tekstury i wyznaczono odpowiednie współczynniki. Korelację pomiędzy wydajnością pracy piły a właściwościami powierzchni (teksturą) określono przy użyciu prostej regresji liniowej oraz regresji wielokrotnej. Otrzymany model poddano następnie walidacji przy pomocy odpowiednich testów statystycznych. Stwierdzono, że pole powierzchni, obwód, równoważne średnice oraz wskaźnik jednorodności uziarnienia mają wpływ na wydajność pracy piły. Opracowany model może być skutecznie wykorzystywany dla wiarygodnego prognozowania postępu prac prowadzonych z wykorzystaniem piły diamentowej