Fatigue limit prediction and analysis of nano-structured AISI 304 steel by severe shot peening via ANN

AISI 304 stainless steel is very widely used for industrial applications due to its good integrated performance and corrosion resistance. However, shot peening (SP) is known as one of the effectual surface treatments processes to provide superior properties in metallic materials. In the present study, a comprehensive study on SP of AISI 304 steel including 42 different SP treatments with a wide range of Almen intensities of 14–36 A and various coverage of 100–2000% was carried out. Varieties of experiments were accomplished for the investigation of the microstructure, grain size, surface topography, hardness and residual stresses as well as axial fatigue behavior. After experimental investigations, artificial neural networks modeling was carried out for parametric analysis and optimization. The results indicated that, treated specimens with higher severity had more desirable properties and performances.

     

低温等离子体技术在高分子材料中的应用研究进展

简要介绍了低温等离子体的定义。综述了近年来低温等离子体技术在高分子材料中应用的最新进展,重点介绍了等离子体技术在纤维织物、塑料、多孔材料、生物材料等改性中的研究进展。阐述了等离子体在材料处理中的应用效果如亲水性、拒水性、黏合性、可纺性、染色整理性能、阻燃性、抗静电性等。最后,指出低温等离子体技术目前存在的问题。     

Experimental investigation of the effect of dispersed silica and alumina nanoparticles on oil-aqueous phase interfacial tension

This work experimentally investigated silicon oxide and aluminum (III) oxide nanoparticles as enhanced oil recovery agents and their effects on wettability and interfacial tension of oil-wetted sandstone and carbonate rocks. The two nanoparticles were selected based on a screening of commercially available nanoparticles with considering the most important parameters. The required time and treatments for the rock samples to become oil-wet, and the required time for the nanofluid to treat each rock sample were also experimentally investigated. Results of this study show that the nanoparticles alter wettability of sandstone and carbonate rocks from oil-wet to water-wet state. It is also observed that sandstone samples are more effected than limestone ones and alumina nanoparticles have greater potential to alter the rock wettability.     

Experimental investigation of effect of asphaltene deposition on oil relative permeability,rock wettability alteration,and recovery in WAG process

Asphaltene deposition is considered to be one of the most problems during oil productions. This work describes the effect of asphaltene precipitation and deposition on relative permeability of reservoir rock during water alternating gas (WAG) injection process. The main objective of this work is experimental investigating of relative permeability change of reservoir fluid due to asphaltene deposition on application of WAG process by use of core flood setup. Result of this paper investigate the relative permeability change during WAG process with different asphaltene content that help to make better development decisions for a reservoir with fluid with specific asphaltene content.     

橡胶型氯化聚乙烯的并用

研究了不同橡胶型氯化聚乙烯(CM)并用时硫化体系及条件、增强体系和增塑剂对并用胶硫化行为及性能的影响.结果表明,将不同的CM并用改善了硫脲-硫黄硫化体系的硫化行为,出现了硫化平坦区.硫化温度为160℃、硫化时间为50 min时,CM并用硫化胶的拉伸强度达到14.8 MPa;将质量比为50/50的炭黑N 375与N 774用于增强CM并用胶时,其硫化胶的永久变形最小;增塑剂有助于改善CM并用硫化胶的弹性及硬度,但其用量不宜过多,以30份(质量)为好;CM并用胶的各项性能指标均可以满足制备大型橡胶制品的要求.     

Wound dressings: Current advances and future directions

Wound healing is a complicated and continuous process affected by several factors, which needs an appropriate surrounding to achieve accelerated healing. Wound healing process recruits three different phases: inflammation, proliferation, and maturation. Due to the different types of wounds, as well as the advancement in medical technology, various products have been developed to repair different skin lesions. Our objective is to investigate the advancement in wound dressings from traditional to the current methods of treatment. The article presents the characteristics of an ideal wound dressing, the requirements for the appropriate selection of different types of wounds, and a detailed classification of wound dressings. Animal origin, herbal origin, and synthetic dressings are firstly introduced and reviewed. Then, nonmedicated dressings including alginate, hydrogel, and hydrocolloid dressings, as well as medicated dressings are discussed. Finally, the developmental prospectives of the new generations of wound dressings for future researches are presented. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47738.     

Electrochemical investigation of sulfonated poly(ether ether ketone)/clay nanocomposite membranes for moderate temperature fuel cell applications

In the present study, polyelectrolyte membranes based on partially sulfonated poly(ether ether ketone) (sPEEK) with various degrees of sulfonation are prepared. The optimum degree of sulfonation is determined according to the transport properties and hydrolytic stability of the membranes. Subsequently, various amounts of the organically modified montmorillonite (MMT) are introduced into the sPEEK matrices via the solution intercalation technique. The proton conductivity and methanol permeability measurements of the fabricated composite membranes reveal a high proton to methanol selectivity, even at elevated temperatures. Membrane based on sPEEK and 1 wt% of MMT, as the optimum nanoclay composition, exhibits a high selectivity and power density at the concentrated methanol feed. Moreover, it is found that the optimum nanocomposite membrane not only provides higher performance compared to the neat sPEEK and Nafion^®117 membranes, but also exhibits a high open circuit voltage (OCV) at the elevated methanol concentration. Owing to the high proton conductivity, reduced methanol permeability, high power density, convenient processability and low cost, sPEEK/MMT nanocomposite membranes could be considered as the alternative membranes for moderate temperature direct methanol fuel cell applications.     

沥青的碳化研究

研究了沥青添加少量的联二蒽醌及预热氧化后再碳化的方法，这种沥青碳化方法可得高产、高质的碳．     

Effects of ultrasonic waves on carbon dioxide solubility in brine at different pressures and temperatures

The adverse impacts of CO₂ emission on the global warming highlight the importance of carbon capture and storage technology and geological storage of CO₂ under solubility trapping mechanisms. Enhancing the solubility of CO₂ in formation water has always been the focus of research in the area of CO₂ sequestration. Ultrasound techniques are one of the environmentally friendly methods that use high-intensity acoustic waves to improve gas solubility in liquids. Ultrasonic waves can alter the properties of different phases that lead to chemical reactions and provide a means to increase the solubility of CO₂ in connate water. In this study, we investigated the effects of ultrasound on the solubility of CO₂ in connate water under different conditions of pressure, temperature, and salinity. The results showed that the solubility of CO₂ was improved with increasing pressure under ultrasonic effects. However, the solubility of CO₂ was inversely proportional to the increase in brine salinity and temperature. Therefore, it was concluded that the solubility of CO₂ might be enhanced in the presence of ultrasound.