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1.
Molecules ; 29(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38893563

RESUMO

This study introduces a novel organosilicon-modified polysaccharide (Si-AP) synthesized via grafting and comprehensively evaluates its performance in water-based drilling fluids (WBDFs). The molecular structure of Si-AP was characterized using Fourier-transform infrared spectroscopy (FTIR) and 1H-NMR experiments. Thermalgravimetric analysis (TGA) confirmed the good thermal stability of Si-AP up to 235 °C. Si-AP significantly improves the rheological properties and fluid loss performance of WBDFs. With increasing Si-AP concentration, system viscosity increases, API filtration rate decreases, clay expansion is inhibited, and drilling cuttings hydration dispersion is suppressed, especially under high-temperature conditions. Additionally, mechanistic analysis indicates that the introduction of siloxane groups can effectively inhibit the thermal degradation of AP chains and enhance their high-temperature resistance. Si-AP can form a lubricating film by adsorbing on the surface of clay particles, improving mud cake quality, reducing the friction coefficient, and significantly enhancing the lubricating performance of WBDFs. Overall, Si-AP exhibits a higher temperature-resistance limit compared to AP and more effectively optimizes the lubrication, inhibition, and control of the filtration rate of WBDFs under high-temperature conditions. While meeting the requirements of drilling fluid systems under high temperatures, Si-AP also addresses environmental concerns and holds promise as an efficient solution for the exploitation of deep-seated oil and gas resources.

2.
Molecules ; 28(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36985623

RESUMO

To study the synergistic catalysis of an ex situ catalyst and in situ clay in the aquathermolysis of heavy oil, in this paper, a series of bentonite-supported catechol-metal complexes were prepared, and the catalytic viscosity reduction performance in the aquathermolysis of heavy oil was investigated. Under the optimized conditions, the viscosity can be reduced by 73%, and the pour point can be lowered by 15.0 °C at most, showing the synergistic catalysis of the ex situ catalyst and in situ clay in this aquathermolytic reaction. Thermogravimetry, physical adsorption-desorption, and scanning electron microscopy were conducted to characterize the thermal stability and microstructure of the ex situ catalyst. The components of the heavy oil before and after the reaction were fully characterized. Six model compounds were used to simulate the aquathermolysis reaction process. In order to study the mechanism of viscosity reduction after the catalytic aquathermolysis reaction, the compounds were analyzed by GC-MS. It is believed that these results will be beneficial in the future for related research in this field.

3.
Biomed Res Int ; 2022: 4171561, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36254140

RESUMO

Objective: This study is aimed at comparing the treatment efficacy between catheter balloon dilation combined with cold fluid compensatory swallowing training and catheter balloon dilation alone on poststroke cricopharyngeal achalasia (CPA). Methods: We conducted a single-blind, randomized controlled trial (RCT). Poststroke patients with CPA were divided into two groups: the control group (treated with catheter balloon dilation) and the trial group (catheter balloon dilation combined with cold fluid compensatory swallowing). Videofluoroscopic swallowing study (VFSS) was performed, and functional oral intake scale (FOIS) was used to evaluate and compare the swallowing function of patients in the 2 groups before and after intervention. Posttreatment VAS pain scores and recovery time were also measured. Results: VFSS and FOIS scores in the two groups were improved after treatment (P < 0.05). In the trial group, VFSS scores in the pharyngeal phase and aspiration degree were significantly higher compared with the control group (P < 0.05) but not in the oral phase (P > 0.05). The difference in FOIS scores and patients' recovery time from intervention to eating mushy food between the trial and control groups was significant (P < 0.05), but not the VAS scores (P > 0.05). Conclusion: The catheter balloon dilation combined with cold fluid compensatory swallowing was superior to catheter balloon dilation alone in terms of relieving dysphagia and reducing aspiration in patients with CPA following stroke. Long-term efficacy should be followed up with more objective and quantitative indicators in future studies.


Assuntos
Transtornos de Deglutição , Acalasia Esofágica , Deglutição , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/terapia , Dilatação , Humanos , Projetos Piloto , Resultado do Tratamento
4.
Polymers (Basel) ; 13(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34372108

RESUMO

Polystyrene is used in a wide range of applications in our lives, from machine housings to plastic cups and miniature electronic devices. When polystyrene is used, a large amount of waste is produced, which can cause pollution to the environment and even harm biological and human health. Due to its low bulk density (especially the foamed type) and low residual value, polystyrene cannot be easily recycled. Often waste polystyrene is difficult to recycle. In this paper, waste polystyrene has been modified by using acetic anhydride which caused a crude oil flow improver. The results showed that modified polystyrene improves the flow properties of the crude oil, reducing the viscosity and the pour point of the crude oil by up to 84.6% and 8.8 °C, respectively. Based on the study of the paraffin crystal morphology, the mechanism of improving the flow capacity of crude oil by modified polystyrene was proposed and analyzed.

5.
PeerJ ; 5: e4024, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29158972

RESUMO

The technology of carbon dioxide (CO2) capture and storage (CCS) has provided a new option for mitigating global anthropogenic emissions with unique advantages. However, the potential risk of gas leakage from CO2 sequestration and utilization processes has attracted considerable attention. Moreover, leakage might threaten soil ecosystems and thus cannot be ignored. In this study, a simulation experiment of leakage from CO2 geological storage was designed to investigate the short-term effects of different CO2 leakage concentration (from 400 g m-2 day-1 to 2,000 g m-2 day-1) on soil bacterial communities. A shunt device and adjustable flow meter were used to control the amount of CO2 injected into the soil. Comparisons were made between soil physicochemical properties, soil enzyme activities, and microbial community diversity before and after injecting different CO2 concentrations. Increasing CO2 concentration decreased the soil pH, and the largest variation ranged from 8.15 to 7.29 (p < 0.05). Nitrate nitrogen content varied from 1.01 to 4.03 mg/Kg, while Olsen-phosphorus and total phosphorus demonstrated less regular downtrends. The fluorescein diacetate (FDA) hydrolytic enzyme activity was inhibited by the increasing CO2 flux, with the average content varying from 22.69 to 11.25 mg/(Kg h) (p < 0.05). However, the increasing activity amplitude of the polyphenol oxidase enzyme approached 230%, while the urease activity presented a similar rising trend. Alpha diversity results showed that the Shannon index decreased from 7.66 ± 0.13 to 5.23 ± 0.35 as the soil CO2 concentration increased. The dominant phylum in the soil samples was Proteobacteria, whose proportion rose rapidly from 28.85% to 67.93%. In addition, the proportion of Acidobacteria decreased from 19.64% to 9.29% (p < 0.01). Moreover, the abundances of genera Methylophilus, Methylobacillus, and Methylovorus increased, while GP4, GP6 and GP7 decreased. Canonical correlation analysis results suggested that there was a correlation between the abundance variation of Proteobacteria, Acidobacteria, and the increasing nitrate nitrogen, urease and polyphenol oxidase enzyme activities, as well as the decreasing FDA hydrolytic enzyme activity, Olsen-phosphorus and total phosphorus contents. These results might be useful for evaluating the risk of potential CO2 leakages on soil ecosystems.

6.
Waste Manag ; 60: 660-665, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27679969

RESUMO

Electric bicycles (e-bicycles) are a primary means of commuting in China because of their light weight, speed, and low maintenance costs. Owing to short service life and environmental pollution hazards, recycling and reuse of e-bicycle batteries has always been a focus of industry and academia. As a typical case of both production and use of large electric bicycles, 113 major sellers, 378 corporate and individual buyers, 147 large e-bicycle repair centers, and 1317 e-bicycle owners in Xuzhou City were investigated in order to understand the sales, use, recycling, and disposal of spent e-bicycle batteries. The findings show that the existing distempered recycling system is the main limitation of spent battery recovery, and the actual recovery rate of spent batteries is lower than the estimated output (QW) for the years 2011-2014. Electric bicycle sellers play a fundamental role in the collection of spent batteries in Xuzhou, accounting for 42.3±8.3% of all batteries recovered. The widespread use of lithium batteries in recent years has resulted in a reduction in spent battery recycling because of lower battery prices. Furthermore, consumer preferences are another important factor affecting the actual recovery rate according to survey results evaluated using canonical correspondence analysis. In this paper, we suggest that a reverse logistics network system for spent battery recycling should be established in the future; in addition, enhancing producer responsibility, increasing publicity, raising of public awareness, developing green public transport, and reducing dependence on e-bicycles also should be pursued. This study seeks to provide guidance for planning construction and management policies for an effective spent battery recycling system in China and other developing countries.


Assuntos
Ciclismo , Fontes de Energia Elétrica , Reciclagem/métodos , Adulto , China , Fontes de Energia Elétrica/estatística & dados numéricos , Política Ambiental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reciclagem/economia , Reciclagem/estatística & dados numéricos , Fatores Socioeconômicos , Inquéritos e Questionários
7.
Artigo em Inglês | MEDLINE | ID: mdl-27598188

RESUMO

This work investigated the spatial profile and source analysis of polycyclic aromatic hydrocarbons (PAHs) in soil that surrounds coal-fired power plants in Xuzhou, China. High-throughput sequencing was employed to investigate the composition and structure of soil bacterial communities. The total concentration of 15 PAHs in the surface soils ranged from 164.87 to 3494.81 µg/kg dry weight. The spatial profile of PAHs was site-specific with a concentration of 1400.09-3494.81 µg/kg in Yaozhuang. Based on the qualitative and principal component analysis results, coal burning and vehicle emission were found to be the main sources of PAHs in the surface soils. The phylogenetic analysis revealed differences in bacterial community compositions among different sampling sites. Proteobacteria was the most abundant phylum, while Acidobacteria was the second most abundant. The orders of Campylobacterales, Desulfobacterales and Hydrogenophilales had the most significant differences in relative abundance among the sampling sites. The redundancy analysis revealed that the differences in bacterial communities could be explained by the organic matter content. They could also be explicated by the acenaphthene concentration with longer arrows. Furthermore, OTUs of Proteobacteria phylum plotted around particular samples were confirmed to have a different composition of Proteobacteria phylum among the sample sites. Evaluating the relationship between soil PAHs concentration and bacterial community composition may provide useful information for the remediation of PAH contaminated sites.


Assuntos
Carvão Mineral , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/química , Centrais Elétricas , Microbiologia do Solo , Bactérias/classificação , Bactérias/efeitos dos fármacos , China , Solo/química , Poluentes do Solo/análise , Emissões de Veículos/análise
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