Silicon - A total of six glass batches (WB100-WB50) based primarily on weathered basalt with successive addition of bypass cement dust (with the weight content 0–50%) were melted at... 相似文献
Cerium oxide nanopowders have been prepared via microwave assisted hydrothermal technique in the presence of different amounts of poly vinyl pyrrolidone (PVP). The prepared nanopowders were characterized using XRD, TEM and SAED. The results showed that the particle size of the ceria nanopowders was decreased with the increase of PVP amount. The prepared ceria has nanocrystalline cubic fluorite structure with high purity. The influence of PVP content on the densification behavior of CeO2 was investigated by means of dilatometer and scanning electron microscopy (SEM). It was found that the increase of PVP amount reduced sintering temperature. The cold-pressed powders can be sintered to full density at temperatures starting from 1070 °C in just 10 min. 相似文献
Four cationic surfactants of quaternary hexammonium silane chloride based on hexamethylenetetramine and alkyl chloride were synthesized. The chemical structures of the prepared cationic surfactants were elucidated using Fourier transform infrared (FT‐IR) spectroscopy and mass spectrometry analysis. The surface and thermodynamic properties of the prepared surfactants were also studied. The performance of these cationic surfactants as microfouling agents against two strains of Gram‐negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli, and two strains of Gram‐positive bacteria, namely, Staphylococcus aureus and Bacillus subtilis, were evaluated as antimicrobial agents. The results showed that the maximum antimicrobial activity was detected for N‐hexamethylenetetramine‐N‐ethyl silane ammonium trichloride (Ah). The maximum and minimum antimicrobial activities were 73 and 60 % against S. aureus and E. coli, respectively, at a concentration of 5 mg/l, pH 7, and 37 °C. 相似文献
Four eco‐friendly nonionic surfactants based on vanillin were investigated as corrosion inhibitors against carbon steel dissolution during the drilling process in the oil field. The corrosion inhibition efficiencies of the tested compounds were determined using weight loss, electrochemical polarization, and electrochemical impedance techniques. The data obtained show that the nonionic surfactants prevent the corrosion of drilling tools and their inhibition efficiency increased with an increase in their concentration. Tafel curves revealed that the surfactants under study act as mixed inhibitors. The adsorption of the inhibitors on carbon steel surface decreases the double‐layer capacitance. The inhibition efficiencies of the surfactants were influenced by their chemical structure and surface activity. 相似文献
In this article, the catalytic conversion of methanol to gasoline range hydrocarbons has been studied over CuO/ NH4‐ZSM‐5(3,5,7,9%) catalysts prepared via sono‐chemistry methods. In order to improve, copper oxide can be used as a booster on NH4‐ZSM‐5 this catalyst property. Accordingly, the conversion process of Methanol to Gasoline (MTG) was conducted under a pressure of 1 atm and temperature of 400°C by a fixed‐bed reactor on copper oxide catalysts which were prepared based on synthetic NH4‐ZSM‐5. The synthetic catalyst was investigated by such analyses as BET, XRD, FT‐IR, and SEM. Formation of copper oxide phase and proper distribution of copper oxide were proven on the basic level of using XRD analysis. BET analysis showed the reduction in catalyst level and SEM images depicted the proper distribution of particles. The present investigation is to study the effect of CuO loading on NH4‐ZSM‐5 support for conversion of methanol to gasoline range hydrocarbons. A series of CuO/ NH4‐ZSM‐5 catalysts were prepared, characterized, and experimented for their performance on methanol conversion and hydrocarbon yield. 相似文献
Viscoelastic surfactants (VES) are used in various oilfield applications such as matrix stimulation and enhanced oil recovery. The loss of surfactants during the propagation of VES could result in a significant reduction in the permeability of the rock (formation damage). The objective of the current work was to identify the effect of rheological behavior of the VES on the formation damage using core‐flooding experiments, nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) analysis. A combination of core‐flooding, NMR, and SEM techniques was used to quantify and identify the location of formation damage in carbonate core samples. The viscosity and storage modulus strongly depend on the nature and concentration of salts. The viscosity increased by increasing the salt concentration up to a specific point (15 wt% CaCl2) and then starts decreasing. The VES formulations that displayed the maximum and minimum viscosities were used to identify the impact of rheological behavior on formation damage. Core‐flooding experiments were performed to assess the formation damage due to high‐viscosity and low‐viscosity VES formulations. The reduction in the permeability of carbonate rocks reaches more than 90% of the initial permeability. It was found that low‐viscosity VES caused more damage compared with high‐viscosity VES when they were used at constant concentrations. NMR and core‐flooding results revealed that the damage took place both in pore body and pore throat. However, most of the surfactant was retained at the pore throat. 相似文献
A series of composites of polycarbonate (PC) with 23 different contents of multiwalled carbon nanotubes (MWNT) was produced by melt mixing using the masterbatch dilution method. In dielectric measurements, AC conductivity and complex permittivity data obtained in the frequency range between 10−3 and 107 Hz at room temperature indicated the electrical percolation threshold at about 1.0 wt%.
The dynamic mode melt rheological measurements for the same samples at eight temperatures between 170 and 280 °C showed a visible change in the frequency dependence of dynamic moduli and the absolute value of the complex viscosity |η*| particularly at low frequencies. In literature these changes are sometimes related to so called ‘percolation threshold concentration’. Applying this picture to our experimental data we have to assume that the percolation threshold is strongly dependent on the measurement temperature. It changes from about 5 to 0.5 wt% MWNT by increasing the measurement temperature from 170 to 280 °C, respectively. This temperature dependence cannot be explained by a classical liquid-solid transition but may be related to the existence of a combined nanotube-polymer network. 相似文献