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991.
Polycrystalline indium phosphide films were successfully deposited on glass and Si substrates by co-evaporating indium and phosphorus from appropriate crucibles. Microstructural studies indicated the average crystallite size to be ∼78 nm. X-ray diffraction pattern indicated reflections from (111), (220) and (311) planes only. The surface roughness of the films was estimated to be 30 nm and the band gap as determined from the transmittance versus wavelength traces was found to be ∼1.42 eV. The PL spectrum measured at 300 K was dominated by a strong peak located ∼1.41 eV. The intensity of this peak increased significantly when recorded at lower (10 K) temperatures and shifted towards higher energy (∼1.54 eV). XPS studies indicated two peaks ∼444.5 eV and ∼451.9 eV, corresponding to peaks of 3d5/2 and 3d3/2 of In 3d core while the P 2p peak at ∼128.8 eV was assigned to only P in InP. Characteristics Raman peaks for InP at ∼303 cm−1 (TO) and ∼342 cm−1 (LO) were observed. 相似文献
992.
Raja Rizwan Hussain 《NDT & E International》2011,44(2):158-162
The most prominent durability concern for reinforced concrete (RC) structures is the corrosion of steel reinforcement in concrete. RC buildings exposed to chloride and high temperature environments like sea and deserts suffer from accelerated corrosion of rebars. The chloride attack and increase in the electro-chemical reaction rate of corrosion due to high temperature is a thermodynamic phenomenon influenced by several parameters and some of them are being neglected in the past research works. The purpose of this present paper is therefore, to model and verify by NDT the coupled effects of chloride and temperature on corrosion of reinforcement throughout the life of concrete buildings by incorporating realistic thermodynamic model evaluations and actual field condition NDT. The model evaluation has been accomplished by the use of concrete durability model as a computational platform on which the corrosion based reinforced concrete building performance and quality at early age and throughout the life of concrete structure is examined in both space and time domains under environmental actions of chloride and temperature. On this line, the thermodynamic modeling evaluation of concrete forms the fundamental core of the theoretical approach to achieve both the scientific knowledge and engineering simulations of altering materials. The NDT results for the effect of chloride and temperature on corrosion have been compared with the DuCOM electro-chemical thermodynamic corrosion model evaluation and are found to be in close agreement with each other. 相似文献
993.
Sana Ullah Sajjad Hussain Waqas Ahmad Hammad Khan Khurram Imran Khan Saad Ullah Khan Sabir Khan 《化学工程与技术》2020,43(3):564-573
Adsorption of dibenzothiophene (DBT) from model oil was investigated using composites of pure activated charcoal and pure bentonite clay. DBT adsorption was carried out in batch mode experiments at laboratory scale, where the developed composite materials showed a synergistic effect in removal of DBT from the model oil in terms of improved surface acidity of the pure activated charcoal and mesoporous structure of the pure bentonite clay. Thermodynamics, kinetics, and optimization of various adsorption parameters were investigated. Kinetic analyses proved that DBT adsorption followed pseudo-second-order kinetics. To study the thermodynamics of the adsorption, different isotherm adsorption models were applied. The Langmuir isotherm best fitted to the adsorption data. Various thermodynamic parameters were evaluated, including Gibbs free energy, entropy, and enthalpy. 相似文献
994.
995.
T. S. M. Al-Saud M. A. A. Bin Hussain E. I. Batyanovskii S. A. Zhdanok A. V. Krauklis P. P. Samtsou 《Journal of Engineering Physics and Thermophysics》2011,84(3):546-553
Results of investigations of the influence of an addition of carbon nanomaterials to a cement paste on its properties, the
morphological characteristics of the cement-hydration products, and the structure and strength of the concrete obtained on
the basis of this paste are presented. 相似文献
996.
997.
Puspamitra Panigrahi Dilip Acharya Sheeba Rathina Selvi Rajeev Ahuja Tanveer Hussain 《International Journal of Hydrogen Energy》2021,46(38):19988-19997
There is a great interest in the design of innovative concepts and strategies of nitrogen rich carboneous materials for exploring their hydrogen (H2) storage properties. Methane (CH4) storage can be an alternative to H2 because the combustion energy of the former is around three times higher than the latter. However, strong inter-molecular repulsion between the CH4 molecules is a major bottleneck to achieve a high gravimetric density. In this study, we use first principles density functional calculations to investigate the coadoption of H2 and CH4 on Li decorated carbon nitride (Li–C7N6) monolayer. The repulsion between CH4 molecules has been avoided by keeping them in asymmetric configuration whereas the repulsion between CH4–H2 is in moderation due to the exploitation of open Li doped sites on C7N6 surface. Though Li–C7N6 has a lower H2 or CH4 storage capacity due to weak van der Waals interactions, the capacity could be doubled with a novel strategy of co-mixing of H2 with CH4 which results into a significantly high gravimetric density of 8.1 wt%. This clearly shows that the CH4–H2 co-mixing strategies have the potential to further propel the prospects of C7N6 monolayers for reversible clean energy storage applications. 相似文献
998.
999.
1000.
Abid Hussain 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2019,36(6):851-862
In the current work, surface-enhanced Raman scattering (SERS) based on gold nanoparticles (AuNPs) and silver-coated gold nanoparticles (Au@AgNPs) with coffee ring effect was employed to simultaneously ascertain urea and ammonium sulfate (AmS) in milk. A small drop (2 µL) of milk with adulterants was dried on a gold-coated slide to examine concentrations ranging from 5, 10, 20, 40 and 80 mg/dL based on spectra ranging from 400 to 1500 cm.?1 A uniform distribution of analytes, with enhanced Raman signals was detected in a small region (maximum 1.9 mm) of coffee ring across the centre of coffee ring pattern. Nanoparticles with core (Au) diameter of 26 nm and shell thickness (Ag) of 6.5 nm were confirmed using transmission electron microscopy (TEM) images. A strong Raman peak at 980 cm?1 was assigned to AmS, while that at 1001 cm?1 was ascribed to urea. With AuNPs, coefficients of determination (R2) of 0.9873 and 0.9859 were achieved for urea and AmS, respectively, while for Au@AgNPs values of 0.9827 and 0.9855 were obtained for urea and AmS, respectively. This study revealed that SERS based on coffee ring effect has the potential to be further exploited for detecting other banned and hazardous adulterants in milk and milk products. 相似文献