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41.
Nourbakhsh Mahsa Darroudi Majid Gholizadeh Mostafa 《Research on Chemical Intermediates》2020,46(1):243-252
Research on Chemical Intermediates - Zinc oxide nanoparticles (ZnO-NPs) are known as a material in the treatment of environmental pollutions. In this study, ZnO-NPs were synthesized using... 相似文献
42.
Basma H. Amin Mohamed I. Abou-Dobara Mostafa A. Diab Essam A. Gomaa Mohammed A. El-Mogazy Adel Z. El-Sonbati Mohamed S. EL-Ghareib Mostafa A. Hussien Hanaa M. Salama 《应用有机金属化学》2020,34(8):e5689
A novel series of mixed-ligand complexes of 5,5′-{(1E,1E′)-1,4-phenelynebis(diazene-2,1-diyl)}bis(quinolin-8-ol) (H2L1) as a primary ligand and 4-aminoantipyrine(L2) as a secondary ligand with Mn(II) ion were prepared using two general formulae: [Mn2(H2L1)2(L2)2X4].4Cl (X = OH2( 1 ), ONO2−( 2 ), Cl=nil; OAc( 3 ), Cl = nil) and [Mn2(H2L1)(L2)2(O2SO2)2]( 4 ). Free ligands and their complexes were characterized. Electronic absorption spectra of the mixed-ligand complexes indicate a distorted octahedral geometry around the central metal ion, and the anions X− are in the axial positions for all compounds. The ligands behave in a neutral bidentate manner, through nitrogen atoms and oxygen atoms of the carbonyl group (L2), whereas H2L1 coordinated through nitrogen and OH groups as a neutral bidentate ligand. All complexes do not contain coordinated water molecules, but complex ( 1 ) contains four water molecules. The water molecules are removed in a single step. The complexes exhibited magnetic susceptibility corresponding to five unpaired electrons. The antimicrobial activity of the Mn(II) mixed-ligand complexes ( 1–4 ) against two gram-positive bacteria, three local gram-negative bacteria, and three fungi species was tested. Mn(II) mixed-ligand complex ( 2 ) exhibited significant antibacterial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas sp. Mixed-ligand complex ( 2 ) exhibited a high potential cytotoxicity against the growth of human lung cancer cells. 相似文献
43.
El-Sayed M. E. Mostafa 《Journal of Applied Mathematics and Computing》2005,17(1-2):1-23
The shortest-paths problem is a fundamental problem in graph theory and finds diverse applications in various fields. This is why shortest path algorithms have been designed more thoroughly than any other algorithm in graph theory. A large number of optimization problems are mathematically equivalent to the problem of finding shortest paths in a graph. The shortest-path between a pair of vertices is defined as the path with shortest length between the pair of vertices. The shortest path from one vertex to another often gives the best way to route a message between the vertices. This paper presents anO(n 2) time sequential algorithm and anO(n 2/p+logn) time parallel algorithm on EREW PRAM model for solving all pairs shortest paths problem on circular-arc graphs, wherep andn represent respectively the number of processors and the number of vertices of the circular-arc graph. 相似文献
44.
The problem of free convection fluid flow and heat transfer of Cu–water nanofluid inside a square cavity having adiabatic square bodies at its center has been investigated numerically. The governing equations have been discretized using the finite volume method. The SIMPLER algorithm was employed to couple velocity and pressure fields. Using the developed code, a parametric study was conducted and the effects of pertinent parameters such as Rayleigh number, size of the adiabatic square body, and volume fraction of the Cu nanoparticles on the fluid flow and thermal fields and heat transfer inside the cavity were investigated. The obtained results show that for all Rayleigh numbers with the exception of Ra = 104 the average Nusselt number increases with increase in the volume fraction of the nanoparticles. At Ra = 104 the average Nusselt number is a decreasing function of the nanoparticles volume fraction. Moreover at low Rayleigh numbers (103 and 104) the rate of heat transfer decreases when the size of the adiabatic square body increases while at high Rayleigh numbers (105 and 106) it increases. 相似文献
45.
Mohammed K. Almoaeet Mostafa Shamsi Hassan Khosravian‐Arab Delfim F. M. Torres 《Mathematical Methods in the Applied Sciences》2019,42(10):3465-3480
We present the method of lines (MOL), which is based on the spectral collocation method, to solve space‐fractional advection‐diffusion equations (SFADEs) on a finite domain with variable coefficients. We focus on the cases in which the SFADEs consist of both left‐ and right‐sided fractional derivatives. To do so, we begin by introducing a new set of basis functions with some interesting features. The MOL, together with the spectral collocation method based on the new basis functions, are successfully applied to the SFADEs. Finally, four numerical examples, including benchmark problems and a problem with discontinuous advection and diffusion coefficients, are provided to illustrate the efficiency and exponentially accuracy of the proposed method. 相似文献
46.
Mostafa M. Amini Amirreza Azadmher Hamid Reza Bijanzadeh Nasser Hadipour 《Journal of inclusion phenomena and macrocyclic chemistry》2006,54(1-2):77-80
Behavior of {[(CH3)2SnCl2·H2O]2·18-crown-6}n in solution have been investigated by HMBC NMR. The results show that coordination of water to tin containing species and
its hydrogen bonding to crown ether remains intact in non-coordinating solvent in contrast to coordinating solvent. H-NMR
reveals that the chemical shift of water in complex varies by solvent of crystallization. 相似文献
47.
Mostafa Malek-mohammadi Akram Heydari-turkmani Saeed Zakavi Nasser Nikfarjam 《应用有机金属化学》2023,37(1):e6927
In this study, the manganese complexes of N-methylated meso-tetra(2-, 3-, or 4 pyridyl)porphyrins, immobilized into the pores of the sodium salt of mesoporous amberlyst 15 nanoparticles (nanoAmbSO3Na), nanoAmbSO3@MnT(2-MePy)P (OAc), nanoAmbSO3@MnT(3-MePy)P (OAc), and nanoAmbSO3@MnT(4-MePy)P (OAc), were synthesized and characterized by field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), nitrogen adsorption/desorption porosimetry analysis, and diffuse reflectance UV–vis spectroscopy. FESEM images revealed a particle size less than ~40 nm for the nanocomposites. The results of BET are in accord with the occupation of the larger pores of the polymer matrix in the case of MnT(2-MePy)P (OAc) as the most sterically demanding metalloporphyrin of the series, and the smaller pores in the case of the other ones. The immobilized manganese porphyrins were used as catalysts for the oxidation of olefins with sodium periodate in the presence of imidazole (ImH) as the co-catalyst. The negligible oxidative destructions of the immobilized manganese porphyrins under the oxidative conditions allowed the comparison of the inherent catalytic activity of the metalloporphyrins, decreased as nanoAmbSO3@MnT(4-MePy)P (OAc) > nanoAmbSO3@MnT(3-MePy)P (OAc) ≫ nanoAmbSO3@MnT(2-MePy)P (OAc). Contrary to the general belief that electron-deficient metalloporphyrins are more efficient catalysts than the electron-rich ones, the most electron-deficient metalloporphyrin of the series, that is, nanoAmbSO3@MnT(2-MePy)P (OAc), showed the lowest catalytic activity. Due to the high oxidative stability of the immobilized manganese porphyrins, ring opening of epoxide competes with the epoxidation reaction to decrease the yield of epoxide at longer reaction times than the optimized one. 相似文献
48.
Ayman H. Kamel Nashwa H. Ashmawy Teraze A. Youssef Mostafa Elnakib Heba Abd El-Naby Hisham S. M. Abd-Rabboh 《Electroanalysis》2023,35(7):e202200436
Herein, two electrochemical methods based on potentiometric and impedimetric transductions were presented for albumin targeting, employing screen-printed platforms (SPEs) to make easy and cost-effective sensors with good detection merits. The SPEs incorporated ion-to-electron multi-walled carbon nanotubes (MWCNTs) transducer. Sensors were constructed using either tridodecyl methyl-ammonium chloride (TDMACl) (sensor I) or aliquate 336S (sensor II) in plasticized polymeric matrices of carboxylated poly (vinyl chloride) (PVC-COOH). Analytical performances of the sensors were evaluated using the above-mentioned electrochemical techniques. For potentiometric assay, constructed sensors responded to albumin with −81.7 ± 1.7 (r2 = 0.9986) and −146.2 ± 2.3 mV/decade (r2 = 0.9991) slopes over the linearity range 1.5 μM–1.5 mM with 0.8 and 1.0 μM detection limits for respective TDMAC- and aliquate-based sensors. Interference study showed apparent selectivity for both sensors. Impedimetric assays were performed at pH = 7.5 in 10 mM PBS buffer solution with a 0.02 M [Fe(CN)6]−3/−4 redox-active electrolyte. Sensors achieved detection limits of 4.3 × 10−8 and 1.8 × 10−7 M over the linear ranges of 5.2×10−8–1.0×10−4 M and 1.4×10−6–1.4×10−3 M, with 0.09 ± 0.004 and 0.168 ± 0.009 log Ω/decade slopes for sensors based on TDMAC and aliquate, respectively. These sensors are characterized with simple construction, high sensitivity and selectivity, fast response time, single-use, and cost-effectiveness. The methods were successfully applied to albumin assessment in different biological fluids. 相似文献
49.
Hanafy AI Maki AK El-Mankhaly K Mostafa MM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(1):133-139
The synthesis of 2,2'-dihydroxy-3,3'-di(carboxymethyl)-1,1'-binaphthyl (H2L) and its novel metal complexes with Co(II), Ni(II), Fe(III) and Th(IV) salts are reported. The ligand and its metal complexes have been characterized on the basis of analytical, conductance, spectral (IR, UV-vis, 1H NMR, mass) and magnetic susceptibility measurements. The M?ssbauer spectrum of the Fe(III) complex indicates a low-spin octahedral geometry around the Fe(III) ion. The IR and 1H NMR spectral data show that the ligand behaves in a dibasic bidentate fashion coordinating to two metal atoms through the two deprotonated naphthyl OH groups and acts in a dibasic tetradentate manner using both carbonyl oxygen's and the deprotonated naphthyl OH groups coordinating to two metal ions. Thermal studies (TGA, DTA) confirm the presence of solvents either inside or outside the coordination sphere and support the mechanism of the decomposition process. The value of [alpha]D20 for the ligand has been determined in DMSO. 相似文献
50.
In bicelle bacteriorhodopsin (bcbR) crystals, the protein has a different structure from both native bacteriorhodopsin (bR) and in-cubo bR (cbR) crystals. Recently, we studied the ability of bcbR crystals to undergo the photocycle upon laser excitation, characterized by the appearance of the M intermediate by single crystal resonance Raman spectroscopy. Calculation of the M lifetime by flash photolysis experiments demonstrated that in our bcbR crystals, the M rise time is much faster than in the native or cbR crystals, with a decay time that is much slower than these other two forms. Although it is now known that the bcbR crystals are capable of photochemical deprotonation, it is not known whether photochemical deprotonation is the only way to create the deprotonated Schiff base in the bcbR crystals. We measured both the visible and Raman spectra of crystals dried under ambient lighting and dried in the dark in order to determine whether the retinal Schiff base is able to thermally deprotonate in the dark. In addition, changes in the visible spectrum of single bcbR crystals under varying degrees of hydration and light exposure were examined to better understand the retinal binding environment. 相似文献