Showing papers by "Minia University published in 1989"
TL;DR: Pyridine adsorption on ceria surfaces, prepared by thermal decomposition of diammonium hexanitratocerate at 400 °C, was studied by infrared spectroscopy and gravimetric techniques as mentioned in this paper.
64 citations
TL;DR: In this paper, the authors focused on the critical analysis of all available drill hole data and seismic reflection records in the Abu Gharadig Basin area, which lies principally to the east of the Qattara Depression in the central portion of the Northern Western Desert of Egypt, and indicated that the basin is an elliptical, multicyclic, E-W trending structurally-controlled basin developed originally as a result of the deep crustal extensional tectonics that affected Northern Egypt during the Mesozoic Era.
54 citations
TL;DR: This article identified 13 flavonoid aglycones from aerial parts of Jasonia montana, including quercetagetin 3,5,6,7,3′-pentamethyl ether.
26 citations
TL;DR: In this paper, seven flavonoids are reported from an aqueous methanol extract of the flowers of Silybum marianum: apigenin 7-O -β-(2″- O -α-rhamnosyl)galacturonide, kaempferol 3-O-α-ρhamnoside-7- O-β-galacturide, apigenIN 7- O −β-glucuronide 6″-ethyl ester, a.k.a.
21 citations
TL;DR: In this paper, the reaction of 3-hydrazino[1, 2, 4]triazino[5, 6-b]indole I with nitrous acid affords the azide III which could be cyclized with acetic anhydride to 10-acetyl-10H-tetrazolo[5′, 1′:3, 4], 1, 4][1,2, 4]-triazin[1.6]-indole IIb.
19 citations
TL;DR: In this paper, a mixture of two-component distributions, one of which is the two-parameter Inverse Gaussian (IG) and the other the twoparameter Weibull (W), is proposed as a failure model.
Abstract: Motivated by the idea that different causes of failure of a given system could lead to different failure distributions, a mixture of two-component distributions, one of which is the two-parameter Inverse Gaussian (IG) and the other the two-parameter Weibull (W), is proposed as a failure model. The IG-W mixture model convers several types of failure rates (FR's). It is shown that depending on the parameter values, the IG-W mixture model is capable of covering six different combinations of FR's, as one of the components has an upsidedown bathtub failure rate (UBTFR) or increasing failure rate (IFR) and the other component has a decreasing failure rate (DFR), constant failure rate (CFR), or IFR. A study is made for the mixed FR based on these six combinations.
19 citations
TL;DR: 2-Amino-4-(3-coumarinyl) thiazole or 3-(w-aminoacetyl) coumarin derivatives, respectively are obtained when 3-acetyl cou marin derivatives are treated with bromine.
Abstract: When 3-acetyl coumarin derivatives are treated with bromine, 3-(w-bromoacetyl) coumarin derivatives are obtained. The reaction of 3-(w-bromoacetyl) coumarin derivatives with thiourea or with amines for two hours leads to the formation of 2-Amino-4-(3-coumarinyl) thiazole or 3-(w-aminoacetyl) coumarin derivatives, respectively. While 3-(w-bromoacetyl) coumarin derivatives react with amines for 5–8 hours to yield imino derivatives of 3-(w-aminoacetyl) coumarin. The antimicrobial activity ofIa-b, IIa-c, IVc-f, IVh andVc, f, h, k, m, andq was studied.
18 citations
TL;DR: The feasibility of a roof-type multistage solar still for agricultural use was studied by estimating the protection effect of plants from strong radiation and the capability of self-supply of required water as discussed by the authors.
17 citations
TL;DR: In this article, the base-adducts of nickel(II) complexes of S-methyl hydrazine carbodithioate Schiff bases with 2,2′-bipyridyl and 1,10-phenanthroline were prepared and isolated in benzene and acetonitrile, and suggested on the basis of IR and electronic spectra.
15 citations
TL;DR: In this paper, non-isothermal kinetic and thermodynamic parameters of ammonium paratungstate decomposition to the onset of formation of WO 3, were determined by analysing thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry(DSC) curves recorded at various heating rates (1 −30°C min −1 ).
14 citations
TL;DR: In this paper, the thermal decomposition of ammonium titanyl oxalate monohydrate (ATO) was investigated in view of its potential as a promising titania precursor in supported titania catalysts prepared by impregnation and subsequent calcination.
TL;DR: Several new azabiaryls and diazabiaryl were synthesized utilizing readily obtainable α, β-unsaturated nitriles as discussed by the authors, and β-Ungesattigte Nitrile fur die Heterocyclen-Synthese: Synthese einiger arlpyridine and Arylpyridazine.
Abstract: Several new azabiaryls and diazabiaryls were synthesized utilizing readily obtainable α, β-unsaturated nitriles.
α, β-Ungesattigte Nitrile fur die Heterocyclen-Synthese: Synthese einiger Arylpyridine und Arylpyridazine
Einige neue Azabiaryle und Diazabiaryle wurden aus leicht zuganglichen α, β-ungesattigten Nitrilen hergestellt.
TL;DR: The following complexes have been prepared and characterized by elemental analysis, IR and visible-UV spectroscopy and by determination of magnetic moments: [ML2(H2O)2] M = Fe(II, Ni(II), Fe(III) and Ni(III), and square planar for M = Cu(II).
Abstract: The following complexes have been prepared and characterized by elemental analysis, IR and visible-UV spectroscopy and by determination of magnetic moments : [ML2(H2O)2] M = Fe(II), Ni(II), [FeClL2(H2O)], [CuL2] (HL = isatin-glycine or isatin-β-alanine); [CoL2] (HL = isatin-β-alanine). The coordination is octahedral for M = Fe(II), Fe(III) and Ni(II), tetrahedral for M = Co(II), and square planar for M = Cu(II).
01 Jan 1989-International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry
TL;DR: The structural changes due to Li2O-doping (2.5 mol%) and γ-irradiation (10-80 Mrad) of NiO were investigated by XRD analyses as mentioned in this paper.
TL;DR: In this paper, the question of conserving the Painleve property of partial differential equations by coordinate transformations is studied, and the effects of some types of transformations of interest, like ordinary Backlund as well as auto-Backlund transformations, are shown as well.
Abstract: In this paper, the question of conserving the Painleve property of partial differential equations by coordinate transformations is studied. Also, the effects of some types of transformations of interest, like ordinary Backlund as well as auto-Backlund transformations of partial differential equations, are shown as well. Some features and comments are given.
TL;DR: Etude de l'effet de L'epaisseur de la couche and de la temperature de recuit sur la resistivite electrique and le coefficient en temperature of the resistivité.
Abstract: Etude de l'effet de l'epaisseur de la couche et de la temperature de recuit sur la resistivite electrique et le coefficient en temperature de la resistivite
TL;DR: Histologic study revealed a moderate to severe degree of vestibular neuroepithelial damage in all of the infused ears, however, significant damage also occurred in the basal turn of the cochlea in a majority of cases.
TL;DR: 50 water samples from 2 public swimming pools were tested for the presence of fungi using the hair baiting technique and plate count methods and Sabouraud's-dextrose agar and Littman-oxgall agar media were used for isolation of the fungi.
TL;DR: In this article, a new method leading to pyrazolo[3,4-e]-1,2,4triazines 5, 8, and 9 by reaction of acyl cyanides with the 3-substituted 4-phenylhydrazono-5-pyrazolamines 1a-d is reported.
TL;DR: Ketoconazole oral therapy had generally slightly higher results than local nystatin therapy in the treatment of vaginal candidosis, yet the difference was statistically insignificant.
TL;DR: In this paper, the synthesis of new 5-(o-substituted arylazo)barbituric acid iron(III), cobalt(II), nickel (II) and copper(II) complexes is reported.
Abstract: The synthesis of new 5-(o-substituted arylazo)barbituric acid iron(III), cobalt(II), nickel(II) and copper(II) complexes is reported. Electronic spectral data, magnetic moment and e.s.r. measurements were recorded in order to elucidate their geometry and mode of bonding (i.r. evidence). The complexes are non-electrolytes.
TL;DR: The effect of 8 growth regulators at concentrations of 1,000, 5,000 and 10,000 ppm on the activity of fungal (Aspergillus flavus var. columnaris) alpha-amylase was studied as mentioned in this paper.
TL;DR: In this paper, the problem of plasma equilibrium in a uniform gravitational field was investigated analytically, where the system of ideal magnetohydrodynamic (MHD) equations were reduced to a single nonlinear elliptic equation of the magnetic potential A, "Grad-Shavranov type equation".
Abstract: The problem of plasma equilibrium in a gravitational field is investigated analytically. For the two-dimensional problem, the system of ideal magnetohydrodynamic (MHD) equations are reduced to a single nonlinear elliptic equation of the magnetic potential A, “Grad-Shavranov type equation”. Using Painleve analysis method, a set of analytical solutions is presented, which are adequate for describing force-free models for solar flares and plane-parallel filaments of diffuse magnetized plasma suspended horizontally in equilibrium in a uniform gravitational field as well.
01 Oct 1989
TL;DR: An analysis of the transient performance of a three-phase induction motor operated from a single-phase supply using the d-q-axis model of the motor is presented to illustrate the accuracy and usefulness of the proposed technique.
Abstract: The authors present an analysis of the transient performance of a three-phase induction motor operated from a single-phase supply. The analysis is performed using the d-q-axis model of the motor. The d-q-axis analysis is simple and can be used to predict steady-state and transient behaviors of the motor. Equivalent d-q circuits for three different connections are used in computer simulations, and the results are presented to illustrate the accuracy and usefulness of the proposed technique. Computed dynamic performances of the three schemes compare reasonably well with the experimental results. >
TL;DR: The cytological effects of two benzoylphenylurea namely XRD 473 and IKI 7899 on mitotic cells of V. faba and H. vulgare caused a depression in mitotic index and the frequency of abberant cells tend to increase by increasing the concentration of the used agents.
Abstract: The cytological effects of two benzoylphenylurea namely XRD 473 and IKI 7899 on mitotic cells of V. faba afd H. vulgare were studied. Both agents caused a depression in mitotic index of V. faba after seed soak and root treatments. Cytological irregularities like chromosome stickiness, laggards, bridges, multipolar cells, unequal chromosomes separation, chromosomal breaks, gaps, ring chromosome, and multinucleated cells were observed in V. faba and H. vulgare. XRD 473 induced a higher frequencies of breakage and reunion type abberations than IKI 7899. A maximum of 7.62% aberrant cells were noticed after root treatment with IKI 7899 in V. faba against 8.0% after root treatment with XRD 473 in H. vulgare. The frequency of abberant cells tend to increase by increasing the concentration of the used agents.
TL;DR: In this article, the synthesis of spiro 1,4-dihydropyridines by a novel and facile one-step method is reported, with a support by another synthetic routes.
Abstract: Synthesis of spiro 1,4-dihydropyridines by a novel and facile one-step method is reported. Structures and reaction mechanisms are also reported with a support by another synthetic routes.
TL;DR: The best temperature for the preservation of A. columnaris alpha-amylase was -5 degrees C followed by 5 degrees C and CaCl2 at 0.005 M had no effect on the activity in both temperatures, while addition of 0.01 M CaCl 2 at pH 5, 6 and 7 resulted in increase of enzyme activity at the temperatures above 50, 40 and 25 degrees C, respectively.
TL;DR: The number size distribution of atmospheric aerosols measured at EL-Minia can be fitted by the power law Δ N/Δ D = 6.5 D −4 in in the size range 0.11 − 6 μm as mentioned in this paper.
TL;DR: Three strains of Bacillus sphaericus H-5a5b designated G. 2 & 20 retained their virulence through 25 successive transfers on nutrient agar and Acetone powder preparations showed high larvicidal activity against C. pipiens, although second instar larvae were more susceptible than fourth instars to all three strains.