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101.
Mohammed M. Rahman Sher Bahadar Khan Abdullah M. Asiri Khalid A. Alamry Aftab Aslam Parwaz Khan Anish Khan Malik Abdul Rub Naved Azum 《Mikrochimica acta》2013,180(7-8):675-685
This paper describes a reliable and sensitive method for sensing dissolved acetone using doped nanomaterials. Large-scale synthesis of ZnO nanorods (NRs) doped with Co3O4 was accomplished by a solvothermal method at low temperature. The doped NRs were characterized in terms of their morphological, structural, and optical properties by using field-emission scanning electron microscopy coupled with energy-dispersive system, UV-Vis., Fourier transform IR, X-ray diffraction, and Xray photoelectron spectroscopy. The calcinated (at 400 °C) doped NRs are shown to be an attractive semiconductor nanomaterial for detecting acetone in aqueous solution using silver electrodes. The sensor exhibits excellent sensitivity, stability and reproducibility. The calibration plot is linear over a large concentration range (66.8 μM to 0.133 mM), displays high sensitivity (~3.58 μA cm?2 mM?1) and a low detection limit (~14.7?±?0.2 μM; at SNR of 3). Figure
The present study describes a simple, reliable, accurate, sensitive, and cost effective method for the detection of acetone using solvothermally prepared semiconductor co-doped nanomaterials. 相似文献
102.
Naved Azum Malik Abdul Rub Abdullah M. Asiri Aftab Aslam Parwaz Khan Anish Khan Sher Bahadar Khan Mohammad M. Rahman Abdulrahman O. Al-Youbi 《Journal of solution chemistry》2013,42(7):1532-1544
Pyrene fluorescence measurements were carried out on various binary mixtures of the antidepressant amphiphilic drug amitriptyline hydrochloride (AMT) with conventional (TTAB and CTAB) and gemini surfactants (14-4-14 and 16-4-16). In all cases mixed micellar aggregates were formed and the mixed critical micelle concentration (cmc) of various mixtures was computed from the I 1/I 3 versus total surfactant concentration plots. In the region where mixed micelles are formed, the interaction of the amphiphlic drug and four surfactants showed synergistic behavior. The results were analyzed using an interaction parameter, β, which characterize the interaction in the mixed micelle and is introduced by a regular solution theory. The β values are negative in all binary mixtures, and their magnitudes increase with increasing hydrophobicity of the amphiphile. The micellar mole fraction of AMT in the mixed micelle (x 1) and in the ideal sate (x ideal) were evaluated and their values (x 1 > x ideal) suggest that the contribution of the AMT component is greater in binary mixtures as compared to that in the ideal state. Activity coefficients (f 1 and f 2) and excess Gibbs energy (G ex) were also calculated. The values of micelle aggregation numbers (N agg) and various other parameters like the Stern–Volmer constant (K sv), micropolarity and dielectric constant of mixed systems have also been evaluated from the ratios of respective peak intensities (I 1/I 3 or I 0/I 1). 相似文献
103.
Malik Abdul Rub Abdullah M. Asiri Anish Khan Aftab Aslam Parwaz Khan Naved Azum Sher Bahadar Khan Kabir-ud-Din 《Journal of solution chemistry》2013,42(2):390-411
Micellization and phase separation of the amphiphilic drug amitriptyline hydrochloride (AMT) in the absence and presence of cationic hydrotropes (aniline hydrochloride, para-toluidine hydrochloride, and ortho-toluidine hydrochloride) have been investigated in the present study. The experimental critical micelle concentration (cmc) values are lower than cmc id values (cmc id is the cmc value at ideal mixing state), indicating attractive interactions between the two components (drug and hydrotrope) in mixed micelles. The bulk behaviors were investigated using the different theoretical models of Clint, Rubingh, Motomura, and Rodenas for comparison of the results of different binary combinations of the drug and hydrotropes. Synergistic interactions were confirmed in all binary combinations at all temperatures, which increase with increasing concentration of hydrotropes. Activity coefficients (f 1 and f 2) were found to be consistently less than unity indicating nonideality in the systems. At a fixed drug concentration (50 mmol·dm?3) and pH (6.7), the hydrotropes showed a continuous increase in the cloud point. Thermodynamic parameters were also evaluated and discussed in detail. 相似文献
104.
Saiyid Aftab Ahmad Zaidi Shahjahan Khwaja Salahuddin Siddiqui 《Transition Metal Chemistry》1993,18(1):51-54
Summary The bidentate nitrogen donor ligands 2-(1-indazolyl) pyridine and 2-(1-indazolyl) pyrimidine have been synthesised. Their complexes with MnII, CoII, NiII, CuII and ZnII have been prepared and characterised by elemental analysis, i.r., u.v. spectra and magnetic susceptibility measurements. The complexes are nonelectrolytes and have magnetic moments consistent with an octahedral environment. 相似文献
105.
A new series of six chromone‐derived compounds and their Cu(II) complexes was synthesized and characterized by their physical, spectral and analytical data The elemental analysis data of the complexes agree well with the proposed composition of the compounds, which were found to be dimeric in nature with two hydrazine molecules bridging the two copper atoms through coordination. The ligands and their Cu(II) complexes were screened for their in‐vitro antibacterial activity against four Gram‐negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri) and two Gram‐positive (Bacillus subtilis, Staphylococcus aureus) bacterial strains by the agar‐well diffusion method. The ligands were found to exhibit either no or low to moderate activities against one or more of the bacterial species, whereas all the metal complexes exhibited moderate to high activities against different bacterial species. The ligands which were inactive before complexation turned active and less active ones became more active upon coordination with copper ions. Overall, the complexes 7–12 showed comparatively much higher activities than the ligands. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
106.
Tariq Aftab M. Masroor A. Khan M. Idrees M. Naeem Nadeem Hashmi Lalit Varshney 《Radiation Physics and Chemistry》2011,80(7):833-836
Degrading the natural bioactive agents by ionizing radiation and then using them as growth promoting substances is a novel emerging technology to exploit the genetic potential of crops in terms of growth, yield and quality. Polysaccharides, such as sodium alginate, have proven to be wonderful growth promoting substances in their depolymerized form for various plants. The effect of depolymerized form of sodium alginate, produced by irradiating the latter by 60Co gamma rays, was studied on Artemisia annua L. with regard to growth attributes, physiological and biochemical parameters and artemisinin content. The study revealed that the irradiated sodium alginate (ISA), applied as leaf-sprays at a concentration of 20–120 mg L?1, improved the growth attributes, photosynthetic capability, enzyme activities and artemisinin content of the plant significantly. Application of ISA at 80 mg L?1 increased the values of the attributes studied to the maximum extent. The enhancement of leaf-artemisinin content was ascribed to the ISA-enhanced H2O2 content in the leaves. 相似文献
107.
Aftab Aslam Parwaz Khan Abdullah M. Asiri Anish Khan Naved Azum Malik Abdul Rub Mohammed M. Rahman Sher Bahadar Khan 《Research on Chemical Intermediates》2013,39(6):2379-2389
The effect of anionic surfactant sodium dodecyl sulfate (SDS) on the rate of oxidation of levothyroxine (LVT) by hexacyanoferrate(III) in alkaline medium has been investigated spectrophotometrically at different temperatures. The reaction follows a complex kinetics showing first order dependence of rate with respect to both alkali and LVT. The effect of SDS on the rate of reaction has been observed at the critical miceller concentration of the surfactant. indicating binding of the substrate with the surfactant micelle. The binding parameters have also been evaluated using the Menger and Portnoy model. 相似文献
108.
Aftab Hussain Hamed Al Sulami Nawab Hussain Hamza Farooq 《Journal of Applied Analysis & Computation》2020,10(6):2313-2322
In this article, we present some fixed disc results for improving contractions in the frame work of F-metric space and to support the new results with examples. There are motivations for volterra Integral equation and findings of the existence of a solution to an initial value problem of second order differential equation. 相似文献
109.
We show that any right semicommutative semigroup satisfying the minimum condition on principal right ideals is saturated. Further we show that if a supersaturated semigroup S has a globally idempotent ideal U which satisfies a nontrivial permutation identity $x_{1}x_{2}\ldots x_{n}=x_{i_{1}}x_{i_{2}}\ldots x_{i_{n}}We show that any right semicommutative semigroup satisfying the minimum condition on principal right ideals is saturated.
Further we show that if a supersaturated semigroup S has a globally idempotent ideal U which satisfies a nontrivial permutation identity
x1x2?xn=xi1xi2?xinx_{1}x_{2}\ldots x_{n}=x_{i_{1}}x_{i_{2}}\ldots x_{i_{n}}
such that i
1=1 and i
n
≠n, then U is also supersaturated. 相似文献
110.
We find some sufficient conditions on semigroup identities in which both sides contain repeated variables to be preserved under epis in conjunction with any seminormal permutation identity. 相似文献