Multi-fractal characteristics of pore structure for coal during the refined upgrading degassing temperatures

The low-temperature nitrogen adsorption measurement is commonly used to describe the pore structure of porous medium, while the role of degassing temperature in the low-temperature nitrogen adsorption measurement does not attract enough attention, various degassing temperatures may lead to the different pore structure characterization for the same coal. In this study, the low-rank coal collected from Binchang mining area, southwest of Ordos Basin was launched the low-temperature nitrogen adsorption measurement under seven various degassing temperatures (120 °C, 150 °C, 180 °C, 210 °C, 240 °C, 270 °C and 300 °C), respectively, the dynamic change of the pore structure under refined upgrading degassing temperatures are studied, and it was also quantitative evaluated with the multi-fractal theory. The results show that the pore specific surface area and pore volume decrease linearly with the increased degassing temperatures, ranges from 12.53 to 2.16 m2/g and 0.01539 to 0.00535 cm3/g, respectively. While the average pore aperture features the contrary characteristics (various from 4.9151 to 9.9159 nm), indicating the pore structure has been changed during the refined upgrading degassing temperatures. With the upgrading degassing temperatures, the sizes of hysteresis loop decrease, and the connectivity of pore structure enhanced. The multi-fractal dimension and multi-fractal spectrum could better present the partial abnormal of pore structure during the refined upgrading degassing temperatures, and the quality index, Dq spectrum, D−10–D10 and multi-fractal spectrum could describe the homogeneity and connectivity of the pores finely. The degassing temperatures of 150 °C, 180 °C and 270 °C are selected as three knee points, which can reflect the partial abnormal of the pore structure during the refined upgrading degassing temperatures. Under the lower degassing temperature (< 150 °C), the homogeneity and connectivity of the pore feature a certain increase, following that it presents stable when the degassing temperatures various from 150 to 180 °C. The homogeneity and connectivity of the pore would further enhanced until the degassing temperature reaches to 270 °C. Because of the melting of the pore when the degassing temperature exceeds 270 °C, the complexity of pore structure increased. In this study, we advise the degassing temperature for low-temperature nitrogen adsorption measurement of low-rank coal should not exceed 120 °C.

Comparison of direct total iron binding capacity by light MgCO3 and heavy MgCO3

Background: The aim of the study is focused to measure TIBC by calculated method (TIBC using the magnesium carbonate- MgCO3 adsorption), measurement of TIBC by calculatory method from automated UIBC and automated Iron measurement. Latter these two values are to be added and would give an additive result of TIBC. The experiment would be performed by using the light MgCO3 powder and the heavy MgCO3 powder and check for any differences in their respective values. Regression analysis, Bland Altman analysis or histogram analysis of TIBC results obtained by calculated methods in patient samples to find correlation between the two methods is being performed.Methods: Samples received for analysis of tests, regardless of patient identification with sample volume serum were used for the study. After complete analysis and reporting of the sample, the leftover serum was used. Serum was kept at room temperature. Then the calculated TIBC from UIBC and the IRON were compared after doing batch calibration for UIBC and lot calibration of Iron.Results: It was found that, this study had positive bias by the usage of the heavy MgCO3 powder. Positive bias in unsaturated iron binding capacity observed by both methods is studied and further investigated using data obtained during the experiment.Conclusions: There is a higher yield of serum obtained with the heavy MgCO3 powder, TIBC calculated from iron and unsaturated iron binding capacity as compared to TIBC measured directly using the light MgCO3 powder.

Fluorescence and biological stabilization of phosphorous-functionalized mesoporous silica nanospheres modified with a bis(8-hydroxyquinoline) Zn complex

Greenish-emitting phosphorous-functionalized mesoporous silica (PMPS) nanospheres were fabricated by modifying their surfaces with (8-hydroxyquinoline) zinc (Znq2). Simulated body fluid soaking test and subsequent gas-adsorption measurement revealed that Znq2-modification could dramatically...

Nearest-neighbor parameter for inosine-cytosine pairs through a combined experimental and computational approach

In RNA secondary structure prediction, nearest-neighbor parameters are used to determine the stability of a given structure. We derived the nearest-neighbor parameters for RNAs containing inosine-cytosine pairs. For parameter derivation, we developed a method that combines UV adsorption measurement experiments with free-energy calculations using molecular dynamics simulations. The method provides fast drop-in parameters for modified bases. Derived parameters were compared and found to be consistent with existing parameters for canonical RNAs. A duplex with an internal inosine-cytosine pair is 0.9 kcal/mol more unstable than the same duplex with an internal guanine-cytosine pair, and is as stable as the one with an internal adenine-uracil pair (only 0.1 kcal/mol more stable) on average.