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101.
102.
Arash Rabbani Todor G. Baychev Shahab Ayatollahi Andrey P. Jivkov 《Transport in Porous Media》2017,116(1):143-161
This article describes experimental results and the numerical validation for multiphase, multicomponent evaporation in porous media 1d flow. We apply the model of Lindner et al. (Transp. Porous Media 112(2):313–332, 2016. doi: 10.1007/s11242-016-0646-6). The permeability of the porous medium is measured in an additional setup with a constant head permeameter to verify the validity of Darcy flow. The heat losses are considered in an analytical approach of correlating measured temperatures and heat inputs with enthalpies. A method of interpreting the experimental results is discussed to determine the phase state. We can show good qualitative agreement of the shift and position of the evaporation region when varying boundary conditions such as mass flux, concentration and heat input. 相似文献
103.
Karimi Zarchi Mohammad Ali Darbandizadeh Mohammad Abadi Seyed Shahab Addin 《Research on Chemical Intermediates》2019,45(5):2605-2639
Research on Chemical Intermediates - Facile and efficient protocols for some multicomponent coupling reactions such as the Suzuki reaction and synthesis of polyhydroquinoline and... 相似文献
104.
Sarkar D Sullivan S Joudaki S Amblard A Holz DE Cooray A 《Physical review letters》2008,100(24):241302
Our ignorance of dark energy is generally described by a two-parameter equation of state. In these approaches, a particular ad hoc functional form is assumed, and only two independent parameters are incorporated. We propose a model-independent, multiparameter approach to fitting dark energy and show that next-generation surveys will constrain the equation of state in three or more independent redshift bins to better than 10%. Future knowledge of dark energy will surpass two numbers (e.g., [w{0},w{1}] or [w{0},w{a}]), and we propose a more flexible approach to the analysis of present and future data. 相似文献
105.
Derakhshan S Kleinke KM Dashjav E Kleinke H 《Chemical communications (Cambridge, England)》2004,(21):2428-2429
HfMoSb4, isostructural with the isoelectronic NbSb2, exhibits nonmetallic properties, as predicted via electronic structure calculations made before the actual discovery of HfMoSb4. 相似文献
106.
Maryam Ganjikhah Shahab Shariati Elahe Bozorgzadeh 《Journal of the Iranian Chemical Society》2017,14(4):763-769
Formaldehyde is known as a highly toxic compound to humans and identified as a carcinogenic substance. In this study, Hantzsch reaction was utilized for the derivatization of trace amounts of formaldehyde in aqueous samples with acetylacetone in the presence of ammonia to form an extractable colored product named 3,5-diacetyl 1,4-dihydrolutidine (DDL) and its further extraction using two-phase hollow fiber liquid-phase microextraction. The main experimental variables affecting the extraction performance were investigated and optimized. Under the optimum conditions (sample volume 12 mL; reaction temperature 70 °C; ammonium acetate buffer solution 4 mL 0.1 mol L?1; acetylacetone 5 mL 0.15 mol L?1; solvent octanol, salt concentration 20% (w/v) NaCl; pH of donor phase 7.0; stirring speed 400 rpm and extraction time 30 min), the linear dynamic range, limit of detection (LOD as 3S b/m) and relative standard deviation (RSD %) of the proposed method were obtained as 5–250 μg L?1 (r 2 = 0.9979), 3.6 μg L?1 and 2.5%, respectively. Finally, the applicability of the proposed method was examined, and very good results were obtained. The results confirmed the applicability of the proposed method as a versatile, low-cost and sensitive preconcentration method for determination of low concentrations of formaldehyde in aqueous solutions. 相似文献
107.
Sulfonic acid groups were grafted onto three different types of synthesized magnetic nanoparticles, namely Fe3O4, Fe3O4@SiO2, and Fe3O4@MCM‐48. The sulfonic acid‐functionalized nanoparticles were evaluated as catalysts for the synthesis of 5‐aryl‐1H‐benzo[f]chromeno[2,3‐d]pyrimidine‐2,4(3H,5H)‐dione derivatives in terms of activity and recyclability. Their catalytic activities were compared with that of the homogeneous acid catalyst 1‐methylimidazolium hydrogen sulfate ([HMIm][HSO4]). The activity of Fe3O4@MCM‐48–SO3H was comparable to those of the other heter‐ogeneous and homogeneous catalysts. 相似文献
108.
Leila Farzin Mojtaba Shamsipur Maryam Shanehsaz Shahab Sheibani 《International journal of environmental analytical chemistry》2017,97(9):854-867
In the present study, a nanocomposite consisting of magnetic reduced graphene oxide decorated with thioglycolic-acid-capped CdTe quantum dots (TGA/CdTe QDs/Fe3O4/rGO) was synthesised using simple ‘hydrothermal method’ and applied as a nanosorbent for extraction and preconcentration of cerium (Ce)(III) from aqueous solutions prior to inductively coupled plasma-optical emission spectroscopy detection. Under the optimised extraction conditions, the calibration graph for Ce(III) was linear in a concentration range of 0.1–511.0 μg L?1 with a correlation coefficient of 0.9986. A detection limit of 0.1 μg L?1 Ce(III) with an enrichment factor of 125 was obtained. Precisions, expressed as relative standard deviation for single-sorbent repeatability and sorbent-to-sorbent reproducibility, were 3.6% and 9.1% (n = 5), respectively. Finally, spiked sea, mineral and tap waters were analysed to evaluate the performance of the proposed method. The high recoveries indicated that the suggested protocol was acceptable for determination of Ce(III) ions in the water samples. The use of QDs and study of their ability for preconcentration of metal ions is an important achievement towards designing novel adsorbents with high efficiency. 相似文献
109.
Spectral,morphological, and antibacterial studies of conducting copolymers,Ppy‐MA,and their nanocomposites,Ag@Ppy‐MA 下载免费PDF全文
Shahab A. A. Nami Mohd. Shoeb Khan Mohammad Arshad Mo Aqib Raza Khan Imran Khan 《先进技术聚合物》2017,28(1):10-19
Pyrrole and methyl anthranilate were copolymerized in different molar ratios in the presence of, H2O2, and FeSO4 at ambient temperature and pressure to obtain efficient conducting copolymers, Ppy‐MA. These conducting copolymers, Ppy‐MA, were in situ reacted with silver nanoparticles to generate nanocomposites, Ag@Ppy‐MA, which exhibit enhanced electrical conductivity. The spectra and morphology of different copolymers, Ppy‐MA, and their nanocomposites, Ag@Ppy‐MA, were analyzed using Fourier transform infrared, SEM, tunneling electron microscopy, X‐ray diffraction, thermogravimetric analysis, and differential thermal analysis. These studies have shown that the nanocomposites, Ag@Ppy‐MA, are thermally more stable and good electrical conductors as compared with their copolymers, Ppy‐MA. The antibacterial activity of the copolymers, Ppy‐MA, prepared from different monomer ratios and their nanocomposites, Ag@Ppy‐MA, has been carried out using disk diffusion method. The copolymers, Ppy‐MA, and its nanocomposites, Ag@Ppy‐MA, were screened against the standard drug Ciprofloxacin. The results clearly suggest that the nanocomposites, Ag@Ppy‐MA, are better antibacterial agent as compared with their copolymers, Ppy‐MA. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
110.
Pourhojat Faegheh Sohrabi Mahmoodreza Shariati Shahab Mahdavi Hamid Asadpour Leila 《Research on Chemical Intermediates》2017,43(1):297-320
Research on Chemical Intermediates - In this study, for the first time, a biocompatible and non-toxic herbal wound dressing was made by encapsulation of Hypericum perforatum alcoholic extract at... 相似文献