ABSTRACT
C9 fraction is the by‐products of catalytic reforming and ethylene cracker; it is considered as a kind of petroleum resin raw material. Recently, it was studied for the use as a gasoline ...additive to enhance the economic benefits. However, C9 fractions are getting higher in sulfur contents. As conventional hydrotreating technology leads to significant octane number loss and processing costs, the alkylation desulfurization process, which could reduce the sulfuric compounds to hydrogen sulfide by catalytic alkylation with olefins and distillation followed by, is a rather attractive way of reducing the sulfur of C9 fraction. In this paper, different kinds of thiophenic compounds, including 2‐ethylthiophen, 2,5‐dimethylthiophene, and 2‐n‐propylthiophene, were selected as the model compounds. Thiophenic compounds were studied first by the alkylation reaction over macroporous sulfonic resin Amberlyst 36, and the octane number of C9 fraction was measured. It was found that isoamylene and Amberlyst 36 resin had a significant effect on the alkylation desulfurization of thiophenic compounds with the conversion, reaching to above 99%. And the octane number of C9 fraction was increased by alkylation desulfurization over Amberlyst 36 resin. Moreover, the alkylation of thiophenic sulfurs could be described as a pseudo–first–order reaction as well as the reaction rate constant, and the activation energy of alkylation reactions was calculated.
A search for C P violation in charmless three-body Ξb− → pK− K− decays is performed using p p collision data recorded with the LHCb detector, corresponding to integrated luminosities of 1 fb−1 at a ...center-of-mass energy √s = 7 TeV, 2 fb−1 at √s = 8 TeV and 2 fb−1 at √s = 13 TeV . A good description of the phase-space distribution is obtained with an amplitude model containing contributions from Σ ( 1385 ) , Λ ( 1405 ) , Λ ( 1520 ) , Λ ( 1670 ) , Σ ( 1775 ) and Σ ( 1915 ) resonances. The model allows for C P -violation effects, which are found to be consistent with zero. The branching fractions of Ξ − b → Σ ( 1385 ) K − , Ξ − b → Λ ( 1405 ) K − , Ξb− → Λ ( 1520 ) K−, Ξb− → Λ ( 1670 ) K−, Ξb− b → Σ ( 1775 ) K− and Ξb− → Σ (1915) K − decays are also reported. In addition, an upper limit is placed on the product of ratios of Ωb− and Ξb− fragmentation fractions and the Ωb− → p K− K− and Ξb− → p K− K− branching fractions.
Fraction magnitude might be represented by the numerical value of the fraction as a whole or might involve separate representations of the values of the fractions' denominator and numerator. Methods ...Subjects 20 right-handed, healthy young adults (11 female, mean age: 23.3 years, SD = 2.6) participated in the fMRI study.
•Mapping the intricate correlation between the three-phase structure and hydrolysis temperature.•The hydrolysis process induces transformations in the three-phase structure.•Temperatures induce ...diverse effects on the hydrolysis rate of semicrystalline PLA.•High-crystalline PLA rapidly hydrolyzes at sub-glass transition temperatures.•Immobilized rigid amorphous phase accelerated hydrolysis near glass transition temperatures.
Hydrolysis significantly influences both the properties and degradability of poly(lactic acid), PLA. This work investigates the hydrolysis kinetics of PLA films as affected by degree of crystallinity and temperatures by considering the three-phase model structures (i.e., mobile amorphous, rigid amorphous, and crystalline). Molecular weight and three-phase fraction analyses were performed during hydrolysis to estimate the kinetic rates using phenomenological models. Results revealed that temperature significantly impacted PLA degradation, with distinct characteristics observed for each of these three phases. Above the glass transition temperature, the hydrolysis rates of PLA were comparable among samples with different crystallinity due to rapid water-induced crystallization of the amorphous phases, coupled with accelerated hydrolysis. In contrast, at below the glass transition temperature, the higher crystallinity sample exhibited a faster hydrolysis rate attributed to the presence of the rigid amorphous fraction. An increase in crystallinity introduced more defects due to limited mobility in the rigid amorphous fraction, influencing hydrolysis. The study provides valuable insights into the crucial relationship between temperature, crystallinity, and hydrolysis kinetics which are expected to be useful for predicting PLA degradation behavior during its intended applications and at its end of life.
Display omitted
Display omitted
•First study on the fate of antibiotic resistance in EKR process with heavy metals.•Heavy metals were reduced with the transformation from stable to reactive forms.•Anti-SMX bacteria ...was more resistant to EKR than anti-OTC bacteria.•Efflux-pumps tet genes were difficult to be removed than cellular-protection genes.•Cu was more closely associated with ARGs than Zn.
Electrokinetic remediation is an effective technology for soil contaminated with heavy metals. However, little is known about the fate of antibiotic resistance in the process under heavy metal stress, since antibiotic resistance genes (ARGs) are widely distributed and can be co-selected with heavy metals. This study focused on antibiotic resistant bacteria and ARGs over different remediation periods (1, 2, and 5 days), voltages (0.4 and 0.8 V cm−1), and initial concentrations (250–1,000 mg kg−1 for Cu, and 1,000–3,000 mg kg−1 for Zn). The application of polarity-reversal maintained a suitable pH, eliminating possible negative effects on soil quality. In addition to a decrease in total metals, the speciation was modified as residual forms decreased while reactive forms increased. Compared with anti-oxytetracycline bacteria, anti-sulfamethoxazole bacteria were more resistant to the electric field, which might be ascribed to greater constraints on their resistance enzymes. The presence of heavy metals accelerated the spread of ARGs, with a 2.67-fold increase for tetG, and a 3.86-fold increase for sul1. Among the ARGs studied, tetM and tetW, as well as sul genes were more easily removed than tetC and tetG genes. Finally, a significant correlation was found between ARGs and Cu, consistent with the relatively stronger toxicity of Cu and its high potential to induce the SOS response. This study advances the understanding of how electrokinetics influences antibiotic resistance in soil with heavy metals, which has important implications for the simultaneous control of these pollutants in soil.
BACKGROUND alpha2-Macroglobulin (alpha2-M) has a curative effect on radiation injury. Virus transmission through plasma derivatives is still not risk-free. Effect of dry heat on alpha2-M activity and ...virus inactivation by dry heat in a new manufacturing process of alpha2-M were studied. STUDY DESIGN AND METHODS Effects of 100°C for 30 minutes, 80°C for 72 hours, and lyophilization on alpha2-M activity were detected, and stabilizing agents were optimized. Effect of a treatment at 100°C for 30 minutes has been tested on a range of viruses and characteristics change of alpha2-M was investigated. RESULTS More than 90 and 80% alpha2-M activity recovery were reserved after treatment at 100°C for 30 minutes and 80°C for 72 hours, respectively. A concentration of 0.05 mol/L histidine presented a better protecting effect for alpha-M activity. No substantial changes were observed in the characteristics of alpha2-M compared with the untreated. By lyophilization and dry-heat treatment at 100°C for 30 minutes, murine encephalomyocarditis virus and pseudorabies virus (PRV) were inactivated below detectable level within 5 minutes (virus titers reduction≥5.75 log) and 30 minutes (virus titers reduction≥6.00 log), respectively. Bovine viral diarrhea virus and porcine parvovirus were inactivated by 4.29 and 2.46 log reduction, respectively. CONCLUSION Treatment at 100°C for 30 minutes could improve the virus safety of alpha2-M with a slight activity loss.
Continuous turnover of intracellular components by autophagy is necessary to preserve cellular homeostasis in all tissues. Alterations in macroautophagy, the main process responsible for bulk ...autophagic degradation, have been proposed to contribute to pathogenesis in Huntington's disease (HD), a genetic neurodegenerative disorder caused by an expanded polyglutamine tract in the huntingtin protein. However, the precise mechanism behind macroautophagy malfunction in HD is poorly understood. In this work, using cellular and mouse models of HD and cells from humans with HD, we have identified a primary defect in the ability of autophagic vacuoles to recognize cytosolic cargo in HD cells. Autophagic vacuoles form at normal or even enhanced rates in HD cells and are adequately eliminated by lysosomes, but they fail to efficiently trap cytosolic cargo in their lumen. We propose that inefficient engulfment of cytosolic components by autophagosomes is responsible for their slower turnover, functional decay and accumulation inside HD cells.
•Structural concrete has been manufactured using recycled brick aggregates.•Coarse and fine natural aggregates have been replaced by recycled brick aggregates.•Percentages of substitution have been ...20%, 35%, 50%, 70% and 100%.•The elastic modulus decreases noticeably when recycled aggregates are used.•Precast pre-stressed joists can be manufactured using recycled aggregates up to 35%.
The European Union has set as a target for 2020 the reuse of 70% of non-hazardous construction and demolition waste (C&DW) in order to reduce its impact on the environment and on health, as well as to improve the efficiency of available resources.
Within the framework of this initiative, this study addresses the use of ceramic aggregates from precast production facilities in order to replace natural aggregates for manufacturing structural concrete for the production of precast prestressed beams. The objective of this study is to evaluate the influence of the substitution of the fine and coarse fraction of natural aggregates for ceramic brick aggregates in the mechanical properties of concrete, with the aim of applying the results obtained to the subsequent manufacture and testing of prestressed beams commonly used in one-way slabs.
The focus of this analysis is on the replacement of the fine fraction of the natural aggregate by the recycled one. However, the coarse aggregate was also substituted. Furthermore, two hardly studied replacement percentages (35% and 70%) were included in the experimental program. The main result obtained was that prestressed beams can be manufactured with up to 35% of the proposed type of ceramic recycled aggregates in order to reach the requirements of the European standards.
Mulching enhances soil C and N fractions compared to no mulching, but its impact on soil microbial communities and their relations to C and N fractions with mulching are not clear. We studied the ...9-yr effect of no mulching (CK), straw mulching (SM), and plastic film mulching (PM) on soil bacterial and fungal community structure and their relationships to soil C and N fractions under dryland winter wheat in the Loess Plateau of China. The SM did not affect bacterial diversity and richness, but enhanced fungal diversity and richness compared to CK in subsoil layers. The PM also increased fungal diversity and richness, but reduced bacterial diversity and richness compared to SM and CK. Compared to CK, the relative abundance of Actinobacteria was lower with SM at 0–10 cm, but the abundances of Nitrospirae, Firmicutes, WS3, and Zygomycota were greater with PM at most soil depths. Bacterial diversity correlated with soil C and N fractions, and fungal richness with potential N mineralization and microbial biomass C and N. Although plastic film mulching enhanced fungal diversity and richness compared to no mulching, straw mulching was more effective in maintaining soil microbial diversity and richness and enhancing soil C and N fractions under dryland winter wheat.
•The effect of mulching on microbial community and C and N fractions was studied.•Straw mulching enhanced soil fungal community and C and N fractions.•Plastic film mulching decreased soil bacterial diversity and richness.•Straw mulching can enhance biological soil health and C and N fractions.
PDF
