A multicomponent wetting model of coal-water-methane-hot flue gas was hereby constructed to investigate the influence of complex components of hot flue gas on coal wettability. Besides, whether it is feasible to use the NIST method to capture the system pressure was verified from a microscopic perspective. Moreover, how the interaction energy and hydrogen bonds between water and coal, the spreading length of water nanodroplets in the
High-voltage thermal breakdown has great potential application in permeability enhancement of coal seam. The characteristics of the breakdown channel, coal element, porosity and microscopic coal petrography of coal under high-voltage electric load were experimentally studied. The coal interior left apparent tracks due to electric current burning with high temperature. The percentage of C, O, Al, Fe, and Si had slightly decreased, while the content of element N increased obviously. Low-pressure nitrogen gas adsorption (LP-N2GA) and mercury intrusion analysis showed that coal porosity increased. The increases of micropores and mesopores are beneficial to promotion of the ability of gas storage, and the increase of macropores could enhance the gas seepage and migration. The results of scanning electron microscope (SEM) show that there are many exogenous fractures in coal, which is also beneficial to gas seepage and migration. The results lay a theoretical foundation for application of high-voltage thermal breakdown in coal mines.
To observe the synergistic effects of hyperthermia in oxaliplatin-induced cytotoxicity in human colon adenocarcinoma Lovo cells.The human colon adenocarcinoma cell line Lovo was obtained from Sun Yat-Sen University. Cells were sealed with parafilm and placed in a circulating water bath, and was maintained within 0.01 °C of the desired temperature (37 °C, 39 °C, 41 °C, 43 °C and 45 °C). Thermal therapy was given alone to the negative control group while oxaliplatin was administered to the treatment group at doses of 12.5 μg/mL and 50 μg/mL. Identification of morphological changes, 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry and Western blotting were used to investigate the effect of thermochemotherapy on human colon adenocarcinoma Lovo cells, including changes in the signal pathway related to apoptosis.A temperature-dependent inhibition of cell growth was observed after oxaliplatin exposure, while a synergistic interaction was detected preferentially with sequential combination. Thermochemotherapy changed the morphology of Lovo cells, increased the inhibition rate of the Lovo cells (P < 0.05) and enhanced cellular population in the G₀/G₁ phase (16.7% ± 4.8 % in phase S plus 3.7% ± 2.4 % in phase G₂/M, P < 0.05). Thermochemotherapy increased apoptosis through upregulating p53, Bax and downregulating Bcl-2. Protein levels were elevated in p53, Bax/Bcl-2 in thermochemotherapy group as compared with the control group (P < 0.05).Thermochemotherapy may play an important role in apoptosis via the activation of p53, Bax and the repression of Bcl-2 in Lovo cells.
High-voltage electrical pulse (HVEP) technology is a useful method to improve the pore structure of coal. However, the breakdown voltage of coal is very high; therefore, it is necessary to improve the conductivity of coal first to decrease its breakdown voltage before subjecting it to HVEP. In this work, a solution of NaCl was used for ameliorating the conductivity of Linhua anthracite coal and Hongliu bituminous coal. Both breakdown voltage and energy consumed by the coal sample saturated with the solution of NaCl decreased. The breakdown voltage of Linhua and Hongliu raw coal sample (RCS) was 3.44 and 2.88 times that of coal saturated with NaCl, respectively. The energy consumed by Linhua and Hongliu RCS was 11.82 and 8.21 times that of coal saturated with NaCl solution, respectively. Scanning electron microscopy images showed that the surface cracks on crushed coal samples after saturating with NaCl solution were more than those on RCS. Nuclear magnetic resonance results indicate that meso- and macropores were chiefly enhanced by the electrical breakdown. Chlorine and sodium elements were found on the surface of both Linhua and Hongliu coal through energy-dispersive spectroscopy point scanning, which indicates that these elements play a positive role in electrical breakdown. A Fourier transform infrared spectroscopy test showed that the discharge channel left a trail of burning on the surface of the coal sample and the changes in the functional groups after crushing.
Physical discharge-based plasma is characterized by high energy density, high temperature, and severe destructiveness. It carries massive Joule heat, and inevitably affects the structures of functional groups. However, previous researches rarely probed into this aspect. This study explores changes of functional groups on coal surface under different breakdown voltages (BVs), which serves as the key to determining the amount of energy injected into plasma channels. This study also explains the influence of BV on functional groups from the perspective of electrical parameters such as voltage, current waveform and deposited energy. The results reveal the following: (1) Under a higher BV, the coal is more likely to be polarized and the pre-breakdown period is shorter; accordingly, the coal can be broken down more easily. (2) The peak current increases linearly with the rise of BV, and the energy conversion efficiency jumps first and then tends to stabilize; (3) The plasma-induced oxidation reaction degree of the coal surface gradually strengthens as the BV rises, because more energy is used for reactions on the coal surface. Specifically, the higher the BV is, the faster the contents of hydroxyl and oxygen-containing functional groups decline, and the faster the aliphatic hydrocarbons in the coal decompose.
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