Properties of vitrinite in bituminous coal and their influence on the structural characteristics of activated carbon

The vitrinite-rich concentrates were extracted respectively from the Datong bituminous coal and the Xinjiang bituminous coal by the density gradient centrifugation method. The activated carbons were prepared by physical activation with carbon dioxide using the above raw coals and vitrinite. The structural properties of vitrinite and the corresponding raw coals were compared, and the characteristics of crystallite and pore structure were analyzed after the carbonization and CO2 activation process. The differences of aromatic and aliphatic hydrocarbon structures of coal and its vitrinite samples were analyzed by Fourier transform infrared spectroscopy. Microcrystalline structure parameters and aromaticity index of coals, chars and activated carbons were analyzed by X-ray diffractometer. The pore structure parameters of chars and activated carbons were studied by the low-temperature nitrogen adsorption method. Compared with raw coals, the crystallite unit sizes of vitrinite were smaller, the length of aliphatic hydrocarbon chain was shorter, and the number of branch chains was larger than those of the corresponding coals, which was beneficial to enhance the fluidity in the carbonization process. Moreover, the weight loss rates of vitrinite were higher, and the weight loss peaks were wider than that of the coals during the carbonization process by thermogravimetric analyzer. The above differences of structural properties and carbonization reactivity of coal and its vitrinite samples could affect the structure characteristics of chars. The results showed that the crystallite lamella size and stacking thickness of vitrinite chars were both increased after carbonization at 850 ℃, while the stacking thickness of crystallite in coal chars was decreased, which indicated that the differences of maceral mainly affected the vertical stacking of crystallite lamella during carbonization. Meanwhile, it led to higher aromaticity and larger BET specific surface area of both vitrinite chars. After the CO2 activation process, the stacking thickness and lamella size of crystallite in activated carbons were lower than that of the corresponding chars, indicating that the crystallite unit got burnt by CO2 activation. The dominant micropore structures were obtained after activation process. The BET specific surface areas of activated carbons from vitrinite reached 744.1 and 797.4 m2/g, respectively, which were significantly higher than that of activated carbons from coals. The micropore and mesopore volumes of vitrinite-based activated carbons were both higher than that of coal-based activated carbons, and the micropore volumes were 1.7−2.2 times more than that of coal-based activated carbons. The above results indicated that the chars with higher aromaticity and more porosity were beneficial to generate micropore structure during activation process

Transcriptome Analysis to Identify Responsive Genes under Sublethal Concentration of Bifenazate in the Diamondback Moth, <i>Plutella xylostella</i> (Linnaeus, 1758) (Lepidoptera: Plutellidae)

Bifenazate is a novel acaricide that has been widely used to control spider mites. Interestingly, we found bifenazate had a biological activity against the diamondback moth (Plutella xylostella), one of the most economically important pests on crucifer crops around the world. However, the molecular mechanisms underlying the response of P. xylostella to bifenazate treatment are not clear. In this study, we first estimated the LC30 dose of bifenazate for third-instar P. xylostella larvae. Then, in order to identify genes that respond to the treatment of this insecticide, the comparative transcriptome profiles were used to analyze the gene expression changes in P. xylostella larvae after exposure to LC30 of bifenazate. In total, 757 differentially expressed genes (DEGs) between bifenazate-treated and control P. xylostella larvae were identified, in which 526 and 231 genes were up-regulated and down-regulated, respectively. The further Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the xenobiotics metabolisms pathway was significantly enriched, with ten detoxifying enzyme genes (four P450s, five glutathione S-transferases (GSTs), and one UDP-Glucuronosyltransferase (UGT)) were up-regulated, and their expression patterns were validated by qRT-PCR as well. Interestingly, the present results showed that 17 cuticular protein (CP) genes were also remarkably up-regulated, including 15 CPR family genes. Additionally, the oxidative phosphorylation pathway was found to be activated with eight mitochondrial genes up-regulated in bifenazate-treated larvae. In contrast, we found some genes that were involved in tyrosine metabolism and purine pathways were down-regulated, indicating these two pathways of bifenazate-exposed larvae were significantly inhibited. In conclusion, the present study would help us to better understand the molecular mechanisms of sublethal doses of bifenazate detoxification and action in P. xylostella

Experimental Investigation of the Decarburization Behavior of Medical Waste Incinerator Fly Ash (MWIFA)

The objective of the research was to compare the flotation performance of medical waste incinerator fly ash (MWIFA) by considering two methods: the cyclonic-static micro-bubble flotation column (FCSMC) method and conventional flotation cell (CFC) method. The results indicated that for FSCMC, the optimum parameters were kerosene = 3.5 g/kg&middot;ash, methyl isobutyl carbinol (MIBC) = 0.2 g/kg&middot;ash, Tween 80 = 7.5% of kerosene concentration, slurry concentration = 100 g/L, and pump speed = 380 r/min. The optimized conditions resulted in a higher dioxin removal efficiency (90.98%), carbon removal efficiency (91.88%) and lower loss on ignition (LOI) (4.96%). The data obtained from the CFC under different optimum operating conditions were 88.65%, 90.63% and 5.68%, respectively. FSCMC was proven to be more efficient for the flotation of MWIFA than CFC

Pore-Scale Imaging of the Oil Cluster Dynamic during Drainage and Imbibition Using In Situ X-Ray Microtomography

We imaged water-wet and oil-wet sandstones under two-phase flow conditions for different flooding states by means of X-ray computed microtomography (μCT) with a spatial resolution of 2.1 μm/pixel. We systematically study pore-scale trapping of the nonwetting phase as well as size and distribution of its connected clusters and disconnected globules. We found a lower Sor, 19.8%, for the oil-wet plug than for water-wet plug (25.2%). Approximate power-law distributions of the water and oil cluster sizes were observed in the pore space. Besides, the τ value of the wetting phase gradually decreased and the nonwetting phase gradually increased during the core-flood experiment. The remaining oil has been divided into five categories; we explored the pore fluid occupancies and studied size and distribution of the five types of trapped oil clusters during different drainage stage. The result shows that only the relative volume of the clustered oil is reduced, and the other four types of remaining oil all increased. Pore structure, wettability, and its connectivity have a significant effect on the trapped oil distribution. In the water sandstone, the trapped oil tends to occupy the center of the larger pores during the water imbibition process, leading to a stable specific surface area and a gradually decreasing oil capillary pressure. Meanwhile, in oil-wet sandstone, the trapped oil blobs that tend to occupy the pores corner and attach to the walls of the pores have a large specific surface area, and the change of the oil capillary pressure was not obvious. These results have revealed the well-known complexity of multiphase flow in rocks and preliminarily show the pore-level displacement physics of the process

Water-out performance and pattern of horizontal wells for marine sandstone reservoirs in Tarim Basin, NW China

Based on geological analysis, reservoir numerical simulation and production performance analysis, water-out performance and pattern of horizontal wells in Tarim marine sandstone reservoir were studied. Compared with continental sandstone reservoirs, the marine sandstone reservoirs in Tarim Basin were characterized by low oil viscosity, good reservoir continuity, and development of interbeds, which together with the large amount of horizontal wells, resulted in fast production rate and high recovery degree of the reservoirs. The main controlling factors of uneven water-out in horizontal wells were reservoir seepage barrier, injection-production well pattern, and dominant seepage channel. Thus 9 types in 4 categories of typical water-out pattern of horizontal wells in Tarim marine sandstone reservoirs were identified, and water-out management measures were proposed for them respectively according to their water-out mechanism and remaining oil distribution characteristics. Finally, the water-out pattern can be identified based on the inflection characteristics of derivative curve of water-oil ratio. This study of the water-out pattern can provide guidance for the adjustment policy of water injection in horizontal wells in marine sandstone reservoirs of Tarim Oilfield. Key words: marine sandstone, water-out performance, water-out pattern, horizontal wells, Tarim Basi

NMR-Based Analysis of Fluid Occurrence Space and Imbibition Oil Recovery in Gulong Shale

The Gulong shale oil reservoir is situated in freshwater to slightly saline lacustrine basins mainly consisting of a pure shale geological structure, which is quite different from other shale reservoirs around the world. Currently, the development of Gulong shale oil mainly relies on hydraulic fracturing, while the subsequent shut-in period for imbibition has been proven to be an effective method for enhancing shale oil recovery. To clarify the characteristics of the fluid occurrence space and the variation in the fluid occurrence during saltwater imbibition in Gulong shale, this paper carried out porosity and permeability tests on Gulong shale cores and analyzed the fluid occurrence space characteristics and imbibition oil recovery based on nuclear magnetic resonance (NMR). In the porosity and permeability tests, T2 distributions were used to correct the porosity measured by the saturation method to obtain the NMR porosity. Combined with the identification of fractures in shale cores using micro-CT and the analysis of porosity and permeability parameters, it was found that the permeability of the shale cores was related to the development of fractures in the shale cores. Through the testing and analysis of T1-T2 maps of the shale cores before and after saturation with oil, it was found that the shale mainly contained heavy oil, light oil, and clay-bound water, and they were distributed in different regions in the T1-T2 maps. Finally, the T1-T2 maps of the shale cores at different imbibition stages were analyzed, and it was found that saltwater mainly entered the minuscule inorganic pores of clay minerals during the imbibition process and squeezed the larger-sized inorganic pores containing light oil through the hydration expansion effect, thus expelling the light oil from the shale core and achieving the purpose of enhanced oil recovery

A therapeutic dose of doxorubicin activates ubiquitin-proteasome system-mediated proteolysis by acting on both the ubiquitination apparatus and proteasome

The ubiquitin proteasome system (UPS) degrades abnormal proteins and most unneeded normal proteins, thereby playing a critical role in protein homeostasis in the cell. Proteasome inhibition is effective in treating certain forms of cancer, while UPS dysfunction is increasingly implicated in the pathogenesis of many severe and yet common diseases. It has been previously shown that doxorubicin (Dox) enhances the degradation of a UPS surrogate substrate in mouse hearts. To address the underlying mechanism, in the present study, we report that 1) Dox not only enhances the degradation of an exogenous UPS reporter (GFPu) but also antagonizes the proteasome inhibitor-induced accumulation of endogenous substrates (e.g., β-catenin and c-Jun) of the UPS in cultured NIH 3T3 cells and cardiomyocytes; 2) Dox facilitates the in vitro degradation of GFPu and c-Jun by the reconstituted UPS via the enhancement of proteasomal function; 3) Dox at a therapeutically relevant dose directly stimulates the peptidase activities of purified 20S proteasomes; and 4) Dox increases, whereas proteasome inhibition decreases, E3 ligase COOH-terminus of heat shock protein cognate 70 in 3T3 cells via a posttranscriptional mechanism. These new findings suggest that Dox activates the UPS by acting directly on both the ubiquitination apparatus and proteasome