Increasing sensitivity of coal analysis by gamma-albedo method.

The article deals with the methodological features of the gamma-albedo method and ways to increase sensitivity of measuring the coal ash content. On the basis of the developed mathematical model the inverse nature of sensitivity of the method is studied depending on the energy of primary gamma radiation. The need for a differentiated account of the nature of scattering that allows using a selective filter as a means of increasing sensitivity is revealed. It is shown that the qualitatively different nature of changing the mass coefficients of coherent and incoherent scattering of gamma radiation from its energy and effective atomic number allows increasing sensitivity of ash measurement according to the value of the ratio of coherently and incoherently scattered gamma radiation intensities. There is given the comparison of the sensitivity data for various modifications of the gamma-albedo method.

Express measurement of solid fuel ash content by nuclear gamma-method.

The methodological features of determining the ash content in coal using scattered gamma radiation are considered in the present study. Theoretical and experimental studies have shown that the integral intensity of secondary (scattered and fluorescent) radiation can serve as an instrumental signal depending on the quality of coal. To achieve a more unambiguous relationship between the integral radiation intensity and the ash content in coal of variable material composition, a compensation technique has been proposed consisting in artificial attenuating secondary radiation. The laws governing the integral intensity of radiation depending on the inverse thickness of the filter are studied, and the results are found to be invariant with variations in the ash composition. A model has been developed to optimize the filtering parameters of secondary radiation by considering the regularity of changes in the filter inversion thickness depending on the ash content.

Influence factor research on deacidification process for high carbon content gas field by numerical simulation-a case study of the Oudeh gas field.

INTRODUCTION: High concentrations of CO2 in natural gas affect its calorific value and corrode the equipment and pipelines related to its transportation and usage. Therefore, strict control over the H2S and CO2 contents in natural gas is essential. CO2 is an important industrial gas that can bring a great deal of economic profit when it is fully utilized. CASE DESCRIPTION: The natural gas produced at the Oudeh gas field in Syria contains high carbon content natural gas, in which the CO2 content is in the range of 17.5-18.8 %, while the H2S content is in the range of 2.8-3.2 %. However, there have been few studies conducted on treatment solutions for natural gas with high carbon contents. In this paper, several commonly used methods for deacidification of natural gas were introduced. Among these methods, the most suitable one was chosen for desulfurization and decarbonization of the natural gas produced at the Oudeh gas field based on its gas quality. CONCLUSIONS: Optimization and analysis of the primary operating parameters for the desulfurization and decarbonization processes were conducted to obtain the optimized values for the input temperature of the lean solution (42 °C), reflux ratio (0.8), number of trays in the absorber unit (17) , and circulation rate of the lean solution (330 m(3)/h), etc. Additionally, the influence of the operating pressure of the regenerator unit on the regeneration system was also investigated. The energy consumption of the apparatus and the corrosion level of sour gas to the apparatus were reduced after optimization. Based on the investigation of the natural gas treatment for this gas field, it can serve as a reference for the purification of high carbon contents natural gas.

Production of peptide antibiotics by Bacillus sp: GU 057 indigenously isolated from saline soil

A total of 112 soil samples were taken from differents areas of district D.I.Khan and Kohat (KPK) Pakistan and screened for production of antibiotics against the Micrococcus luteus and Staphylococcus aureus. Widest zone of inhibition (18mm) was produced by microorganism isolated from saline soil. The strain was later identified as Bacillus GU057 by standard biochemical assays. Maximum activity (18mm inhibition zone) was observed against Staphylococcus aureus after 48 hours of incubation at pH 8 and 4% concentration of glucose. The antibiotic was identified by autobiography as bacitracin. The Bacillus strain GU057 was confirmed as good peptide antibiotic producer and can effectively be indulged as biocontrol agent.

Production of peptide antibiotics by Bacillus sp. GU 057 indigenously isolated from saline soil.

A total of 112 soil samples were taken from differents areas of district D.I.Khan and Kohat (KPK) Pakistan and screened for production of antibiotics against the Micrococcus luteus and Staphylococcus aureus. Widest zone of inhibition (18mm) was produced by microorganism isolated from saline soil. The strain was later identified as Bacillus GU057 by standard biochemical assays. Maximum activity (18mm inhibition zone) was observed against Staphylococcus aureus after 48 hours of incubation at pH 8 and 4% concentration of glucose. The antibiotic was identified by autobiography as bacitracin. The Bacillus strain GU057 was confirmed as good peptide antibiotic producer and can effectively be indulged as biocontrol agent.

Correlation between image quality and radiation dose on screening mammography / 中华放射医学与防护杂志

Objective To obtain the matched parameters between image quality and radiation dose by exploring the influence of the exposure parameters of screening mammography on both the image quality and radiation dose.Methods The correlation between the exposure parameters and average glandular doses to 507 patients undergoing screening mammography were retrospectively analyzed.The influence of breast compression thickness on radiation dose by exposing different thickness of PMMA was obtained.The correlation with image quality was analyzed by combined testing of contrast detail test mode ( CDMAM3.4 )and different thickness of PMMAs.Results The groups aged 30 to 49 years were the main groups in 507examined patients,up to 67.06％ of the total.The mean value of average gland doses ( AGD ) in contrastprior mode was the highest in three kinds of exposure modes,accounting for 137.5％ of standard mode.In standard mode,target material/filtration board combination was Mo/Mo,Mo/Rh and Rh/Rh,accounting for 1/3 respectively.Mo/Rh and Rh/Rh were selected in dose-prior mode,accounting for 50％ respectively.Mo/Mo was mainly selected in contrast-prior,accounting for 52％.Breast compression thickness was positively correlated with average gland doses.Image quality figure inverse (IQFinv) under three kinds of modes (STD,DOSE,CNT) was 98.32,95.41 and 107.02,respectively,and IQFinv of contrast-prior mode was the highest among them.IQFinv was in general agreement in the three kinds of exposure modes when the thickness of PMMA plates plates was greater than or equal to 5 cm.Conclusions In clinical practice,when the breast is of density type and pressed thickness is less than 4 em,the dose-prior mode should be selected.When the pressed thickness is between 4 and 6 cm,the standard exposure mode should be selected.When the pressed thickness is larger than 6 cm,the manual mode should be selected.