Numerical Simulation of the Tar Mist and Dust Movement Process in a Low-Temperature Dry Distillation Furnace

In the low-temperature dry distillation of low-rank coal, the important liquid product of coal tar is produced, but its quality and utilization rate are degraded by entrained dust. The movement of coal tar and dust in the furnace is a key factor in causing particles such as dust to mix with coal tar. Therefore, the Euler–Lagrangian method is used to simulate the two-phase motion process of gas, tar, and dust in a furnace. By considering the effects of tar particle size, dust particle size, gas velocity, tar density, and dust density, the motion process mechanism is revealed, enabling the dust content in coal tar to be reduced and the quality improved. The results indicate that tar particles with sizes less than 0.20 mm can be removed from the furnace by gas, and the smaller the particle size is, the shorter the time required for removal. Dust particles greater than 0.18 mm in size cannot be completely removed from the furnace. As the gas velocity increases, the time required for complete removal of the tar mist and dust gradually decreases. When the speed is 0.70 m/s, all tar mist is removed, although some particles remain. Tar mist with a density of more than 900 kg/m3 can be extensively removed, but dust with a density of more than 1400 kg/m3 is difficult to remove and remains in the furnace. Finally, particle size distribution experiments in the product were conducted to verify the accuracy of the numerical simulation

Insights into the Oil Adsorption and Cyclodextrin Extraction Process on Rough Silica Surface by Molecular Dynamics Simulation

Molecular dynamics simulation was performed to investigate the adsorption and aqueous extraction of oil contaminants on silica surface with various roughness. The oil dispersion and immersion were characterized by molecular configuration, adsorption energy, and contact angle, while the oil detachment in water and cyclodextrin solution was evaluated by the overall extractability, extractability from the individual groove, and free energy analysis. Results demonstrated that the main resistance for oil release from the relatively shallow grooves was the strong intermolecular interactions among the oil molecules orderly stacked inside the grooves. It highlighted the role of cyclodextrin in breaking through the energy barrier for pulling out one oil molecule from the tightly stacked oil structure, which resulted in the fast release of the remaining oil. Previous studies attributed the oil extraction to the sequestration of oil into the hydrophobic cavity of cyclodextrin, while our results demonstrated that such an inclusion process was critical in initially destroying the stable structure of the oil compacted inside the grooves but contributed little afterward. To the best of our knowledge, this was the first molecular-level study on the cyclodextrin-aided oil detachment from a mineral surface, which improves our understanding of the oil cleanup mechanisms during aqueous extraction

Photoelectrochemical sensor based on Bi2(Te1-xSex)3 for the sensitive detection of the tetracycline hydrochloride

Tetracycline hydrochloride (TC-HCl) as an antibiotic is widely used in our daily life, but it has posed potential threats to the ecological environment for flowing into the natural environment. To address this issue, The photoelectrochemical (PEC) sensor is first developed for the detection of TC-HCl by comparing and analyzing ternary Bi2(Te1-xSex)3 nanomaterials prepared through different ratios of hydrothermal methods. Specifically, the Bi2(Te1-xSex)3/Indium tin oxide (ITO) electrode can interact with TC-HCl rapidly and selectively which results in a significant reduction of the photocurrent signal. By regulating the ratio of x, it is found that Bi2Te2.85Se0.15/ITO have the best stability and the fastest response time in the detection of TC-HCl. The response/recovery speed of the sensor to TC-HCl is fast to 0.23 s, a low detection limit of 0.08 pmol/l (S/N = 3) and a linear detection fit of up to R2 = 0.992. Moreover, the sensor has good stability and specificity for TC-HCL detection, providing a new perspective for the development of PEC sensors

Evaluation of Preparation and Detoxification of Hemicellulose Hydrolysate for Improved Xylitol Production from Quinoa Straw

Quinoa straw is rich in hemicellulose, and it could be hydrolyzed into xylose. It is a promising energy resource alternative that acts as a potential low-cost material for producing xylitol. In this study, quinoa straw was used as a substrate subjected to the hydrolysis of dilute sulfuric acid solution. Based on the production of xylose and inhibitors during hydrolysis, the optimal conditions for the hydrolysis of hemicellulose in quinoa straw were determined. Detoxification was performed via activated carbon adsorption. The optimal detoxification conditions were determined on the basis of major inhibitor concentrations in the hydrolysate. When the addition of activated carbon was 3% at 30 °C for 40 min, the removal of formic acid, acetic acid, furfural, and 5-HMF could reach 66.52%, 64.54%, 88.31%, and 89.44%, respectively. In addition to activated carbon adsorption, vacuum evaporation was further conducted to perform two-step detoxification. Subsequently, the detoxified hydrolysate was used for xylitol fermentation. The yield of xylitol reached 0.50 g/g after 96 h of fermentation by Candida tropicalis (CICC 1779). It is 1.2-fold higher than that obtained through the sole vacuum evaporation method. This study validated the feasibility of xylitol production from quinoa straw via a biorefinery process

Fate of Copper in Saline–Alkali Soil with Long-Term Application of Biogas Residue

The retention of copper (Cu) in saline–alkali soil (SAS) during long-term application of biogas residue (BR) with a high concentration of Cu raises concerns. In this work, the fate of Cu was detected using adsorption isotherms, scanning electron microscope—energy dispersive spectrometer, Fourier transform infrared spectrometer, X-ray diffraction, isothermal titration calorimetry, X-ray photoelectron spectroscopy, and microzone X-ray fluorescence spectrometer. The results showed that the main groups for Cu adsorption by SAS and BR were carboxyl, hydroxyl, amide and amine. The adsorption of Cu by the carboxyl group was entropy–enthalpy co-driven (|ΔH| |TΔS|, ΔH > 0). The adsorption of Cu on the SAS and BR was achieved by organic matter rather than minerals. The degradation of BR in the SAS increases the content of Cu adsorption groups such as carboxyl and amine groups, and Cu was adsorbed on the surface or inside SAS through organic groups. This study provides further theoretical support for the application of BR in SAS

Finite field regime for a quantum spin liquid in α−RuCl3

An external magnetic field can induce a transition in α−RuCl3 from an ordered zigzag state to a disordered state that is possibly related to the Kitaev quantum spin liquid. Here, we present field-dependent inelastic neutron scattering and magnetocaloric effect measurements implying the existence of an additional transition out of the quantum spin-liquid phase at an upper field limit Bu. The neutron scattering shows three distinct regimes of magnetic response. In the low-field ordered state the response shows magnon peaks; the intermediate-field regime shows only continuum scattering, and above Bu the response shows sharp magnon peaks at the lower bound of a strong continuum. Measurable dispersion of magnon modes along the (0,0,L) direction implies non-negligible interplane interactions. Combining the magnetocaloric effect measurements with other data, a T−B phase diagram is constructed. The results constrain the range where one might expect to observe quantum spin-liquid behavior in α−RuCl3

AKT-mediated phosphorylation of ATG4B impairs mitochondrial activity and enhances the Warburg effect in hepatocellular carcinoma cells

<p>Phosphorylation is a major type of post-translational modification, which can influence the cellular physiological function. ATG4B, a key macroautophagy/autophagy-related protein, has a potential effect on the survival of tumor cells. However, the role of ATG4B phosphorylation in cancers is still unknown. In this study, we identified a novel phosphorylation site at Ser34 of ATG4B induced by AKT in HCC cells. The phosphorylation of ATG4B at Ser34 had little effect on autophagic flux, but promoted the Warburg effect including the increase of L-lactate production and glucose consumption, and the decrease of oxygen consumption in HCC cells. The Ser34 phosphorylation of ATG4B also contributed to the impairment of mitochondrial activity including the inhibition of F₁Fo-ATP synthase activity and the elevation of mitochondrial ROS in HCC cells. Moreover, the phosphorylation of ATG4B at Ser34 enhanced its mitochondrial location and the subsequent colocalization with F₁Fo-ATP synthase in HCC cells. Furthermore, recombinant human ATG4B protein suppressed the activity of F₁Fo-ATP synthase in MgATP submitochondrial particles from patient-derived HCC tissues in vitro. In brief, our results demonstrate for the first time that the phosphorylation of ATG4B at Ser34 participates in the metabolic reprogramming of HCC cells via repressing mitochondrial function, which possibly results from the Ser34 phosphorylation-induced mitochondrial enrichment of ATG4B and the subsequent inhibition of F₁Fo-ATP synthase activity. Our findings reveal a noncanonical working pattern of ATG4B under pathological conditions, which may provide a scientific basis for developing novel strategies for HCC treatment by targeting ATG4B and its Ser34 phosphorylation.</p