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11.
A new, simple and low‐cost method for patterning hydrophobic barriers in porous support such as paper by Parafilm® has been introduced. This method is then used for electrochemical paper‐based ammonia sensor construction. Ammonia sensor is based on electrochemical concentration cell which ammonia reaction with electrolyte in halves cell caused in concentration gradient and therefore potential difference dependent on ammonia concentration. The effect of concentrations of the involved chemicals, time periods of the required processes, the presence of Faraday cage as well as the effects of different salts used in the salt bridge on the response of the sensor, were investigated in order to find the optimized conditions. 相似文献
12.
Bahram Mokhtari 《Supramolecular chemistry》2013,25(10):696-702
The competitive solvent extraction of alkaline earth metals using different nano-baskets was investigated. The novelty of this work is to study the correlations between the isomer structure of calixarenes and their extraction properties. The objective was to quantify the effects of aryl groups in the ionisable pendant moieties, calixarene conformation, steric orientations (cis- and trans-) and relative positions (ortho- and para-) of pendant moieties upon the extraction efficiency, pH1/2 and the selectivity of calix[4]arene complexes. Alkaline earth metals were extracted from aqueous solutions into chloroform by di-ionisable calix[4]arenes and were measured using ion chromatography. The results revealed that alternation of aryl group in the pendant moieties, changing their orientation from cis- to trans-analogues as well as from ortho- to para- analogues, showed no changes in the selectivity, the extraction efficiency and the pH1/2 of calix[4]arene complexes. Changing the scaffold of calixarene's ring to the cone, 1,2-alternate and partial-cone conformers altered their complexation ability towards alkaline earth metals and their extraction efficiency. 相似文献
13.
This article describes the preconcentration of methyl methacrylate in produced water by the dispersive liquid–liquid microextraction using extraction solvents lighter than water followed by gas chromatography. In the present experiments, 0.4 mL dispersive solvent (ethanol) containing 15.0 μL extraction solvent (toluene) was rapidly injected into the samples and followed by centrifuging and direct injection into the gas chromatograph equipped with flame ionization detector. The parameters affecting the extraction efficiency were evaluated and optimized including toluene (as extraction solvent), ethanol (as dispersive solvent), 15 μL and 0.4 mL (as the volume of extraction and dispersive solvents, respectively), pH 7, 20% ionic strength, and extraction's temperature and time of 20°C and 10 min, respectively. Under the optimum conditions, the figures of merits were determined to be LOD = 10 μg/L, dynamic range = 20–180 μg/L, RSD = 11% (n = 6). The maximum recovery under the optimized condition was determined to be 79.4%. 相似文献
14.
Hamid Hadi-Alijanvand Ali A. Moosavi-Movahedi Bahram Goliaei 《Journal of the Iranian Chemical Society》2013,10(5):907-914
Prolyl hydroxylase domain 2 containing protein (PHD2) is a central protein in regulation of cellular response to hypoxia. This protein controls the responses of cell to oxygen level via the regulation of hypoxia inducible factor (HIF) stability. HIF induces the expression of many genes, especially ones orchestrate angiogenesis. There are some reports that mentioned in some tumor types the level of HIF is high in spite of the presence of wild-type PHD2 and normoxic environment. Therefore, the possibility of PHD2 misfolding in some cancer cells arises. Studying such important protein unfolding pathway is insightful for possible therapeutic approaches. In this study, the unfolding pathway of PHD2 illustrates utilizing molecular dynamics simulation of protein thermal denaturation. Based on current study results, we represent the possible mechanisms of PHD2 unfolding in detail. The possible intermediates of PHD2 thermal unfolding are characterized, and the most venomous state of its unfolding pathway is introduced. 相似文献
15.
Journal of Thermal Analysis and Calorimetry - The increasing growth of helium consumption in industries and the limited resources of this element are the challenges that industries will face in the... 相似文献
16.
Ghorbani Bahram Mehrpooya Mehdi Aasadnia Majid 《Journal of Thermal Analysis and Calorimetry》2021,146(3):1255-1281
Journal of Thermal Analysis and Calorimetry - This work presents numerical simulation of two-dimensional thermogravitational energy transport in a chamber filled with copper–water ( $${\hbox... 相似文献
17.
Pattern recognition by use of polarimetric phase-shifting digital holography is presented. Using holography, the amplitude distribution and phase difference distribution between two orthogonal polarizations of three-dimensional (3D) or two-dimensional phase objects are obtained. This information contains both complex amplitude and polarimetric characteristics of the object, and it can be used for improving the discrimination capability of object recognition. Experimental results are presented to demonstrate the idea. To the best of our knowledge, this is the first report on 3D polarimetric recognition of objects using digital holography. 相似文献
18.
19.
Yaghoubi-berijani Marzieh Bahramian Bahram Zargari Solmaz 《Research on Chemical Intermediates》2020,46(1):197-213
Research on Chemical Intermediates - The bismuth oxybromide (BiOBr) photocatalyst was first synthesized via a simple co-precipitation method. To improve the visible light photocatalytic activity of... 相似文献
20.
Faezeh Toutounian Davod Khojasteh Salkuyeh Bahram Asadi 《Journal of Applied Mathematics and Computing》2005,17(1-2):457-473
In each step of the quasi-minimal residual (QMR) method which uses a look-ahead variant of the nonsymmetric Lanczos process to generate basis vectors for the Krylov subspaces induced byA, it is necessary to decide whether to construct the Lanczos vectorsv n +1 andw n +1 as regular or inner vectors. For a regular step it is necessary thatD k =W k T V k is nonsingular. Therefore, in the floating-point arithmetic, the smallest singular value of matrix Dk,σ min (D k ), is computed and an inner step is performed ifσ min (D k )<∈, where ∈ is a suitably chosen tolerance. In practice it is absolutely impossible to choose correctly the value of the tolerance ∈. The subject of this paper is to show how discrete stochastic arithmetic remedies the problem of this tolerance, as well as the problem of the other tolerances which are needed in the other checks of the QMR method with the estimation of the accuracy of some intermediate results. Numerical examples are used to show the good numerical properties. 相似文献