Khalaf Ali Fayez Abuamra

استاذ - أستاذ متفرغ

كلية العلوم

العنوان: قسم النبات والميكروبيولوجى -كلية العلوم -جامعة سوهاج



المنشورات و المؤلفات التي تحتوي علي الكلمة المفتاحية: Kinetics

2019-12-04 10:11:48 الكلمات المفتاحية Kinetics, humic acid, smectite, Adsorption, background electrolyte,
Kinetic study of humic acid adsorption onto smectite: The role of individual and blend background electrolyte
Many factors can affect the natural organic matter adsorption on clay, such as pH and ionic strength. Blended background electrolyte could be causing better simulation to natural effects. Therefore, kinetic study of humic acid (HA) adsorption onto smectite has been studied under various conditions. Impact of pH and individual and blend background electrolyte with different ionic strength concentration on the ... إقراء المزيد

A comparative study for the effect of nano-sized Moringa oleifera and Delonix regia for removal heavy ions from water
The ability of natural biosorbents for removing heavy metal ionswere investigated by studying the effect of nano sized _Delonixregia _and _Moringa__ oleifera_on adsorption of Cd2+and Pb2+ions from aqueous solution. The investigated biosorbents (_Delonixregia_and _Moringa__oleifera)_ were characterized by FT-IR, SEM, TEM, XRD and EDS techniques.The influence of pH, temperature, adsorbent dosage, contact time and initial metal ion concentration on adsorption process ... إقراء المزيد

2018-11-28 16:53:16 الكلمات المفتاحية chromen-2-one, laser dyes, hydroxide ion attack, Kinetics,
Kinetic study and reactivity trends of hydroxide ion attack on some chromen-2-one laser dyes in binary water–methanol and water–acetone mixtures
We have investigated the kinetics of hydroxide ion attack at iron(II) chelates with 5-bromosalicylidene derivatives of amino acids (alanine, phenylalanine, aspartic acid, histidine, and arginine) in binary aqueous mixed solvents at 298 K. The observed reactivity trends are discussed in connection with the complexes hydrophobicity/hydrophilicity, transfer chemical potentials of hydroxide ion and the complex, and the solvent effects. إقراء المزيد

2018-11-28 16:21:43 الكلمات المفتاحية hydroxide ion attack, ONO donors, Kinetics,
Kinetic study of the hydroxide ion attack on and DNA interaction with high spin iron(II) Schiff base amino acid chelates baering ONO donors
Kinetic study of some novel high spin Fe(II) complexes of Schiff base ligands derived from 5- bromsalicyaldehyde and amino acids with the OH– ion and DNA has been carried out. Based on the kinetic data, the rate law and a plausible mechanism were proposed. Kinetic data of the base catalyzed hydrolysis imply pseudo first-order double stage process due to the ... إقراء المزيد

2018-11-18 11:22:30 الكلمات المفتاحية solvent effect, Kinetics, methanol, acetone, base hydrolysis,
Kinetics, Reactivity, Initial–Transition State Analysis and Thermodynamic Parameters of Base-Catalyzed Hydrolysis of Coumalic Acid in Solvents of Different Polarities
Base-catalyzed hydrolysis of coumalic acid (COU) in aqueous-methanol and aqueous-acetone mixtures has been studied kinetically at temperature range from 283 to 313 K. Moreover, the change in the activation energy barrier of COU from water to water–methanol and water–acetone mixtures is estimated from the kinetic data. Solvent effects on reactivity trends have been analyzed into initial and transition state components. ... إقراء المزيد

2018-11-27 23:52:20 الكلمات المفتاحية 6-amino coumarin, base hydrolysis, Kinetics,
Synthesis of novel coumarin derivatives based on 6-aminocoumarin, kinetics inspection of base hydrolysis, and spectrophotometric tracer of intermediate progress
The kinetics of the base hydrolysis of 6-aminocoumarin and some of its derivatives was studied spectrophotometrically in aqueous medium at 298 K under pseudo-firstorder conditions ([OH-][[[Compound]). The suggested general rate equation can be given as: rate = {k1 ? k2 [OH-]} [complex]. The reasonable mechanism suggested that the investigated reaction proceeded via the formation of an intermediate and the ring ... إقراء المزيد

Solvent Effects on The reactivity Trends of some Coumarin Derivatives
Kinetic results, rate laws and reaction mechanisms were established for the base hydrolysis of 7-hydroxycoumarin (HC), 7-hydroxycoumarin-4-acetic acid (HCA), 6-nitrocoumarin (NC), 6-nitrocoumarin-3-carboxylic acid (NCC), 7-dimethylamino-4-methylcoumarin (DMAC), 7-diethylamino-4-methylcoumarin (DEAC) and coumalic acid (COU) in aqueous solution, water-methanol and water-acetone mixtures. The kinetics of the base hydrolysis followed a rate law with kobs= k2[OH-] for all coumarin derivatives under study except 6-nitrocoumarin-3-carboxylic ... إقراء المزيد

2018-10-01 14:10:56 الكلمات المفتاحية Iron Complexes, DNA interaction, Hydrolysis, Kinetics,
Kinetics of Alkaline Hydrolysis and DNA Interaction of Iron Complexes
Air and moisture stable coordination compounds of some first transition metals such as Cr (III), VO (II), Ni(II) and Mn(II) with newly designed tri- and tetra-dentate imine ligands (HNAP, HNPN and ESPN) were synthesized. Tridentate imine ligands (HNAP, ESAP) were synthesized by reacting 2-hydroxynapthaldehyde (HN) with 2-aminophenol (AP), whereas tetra-dentate imine ligands (HNPN and ESPN) were prepared by reacting 2-hydroxy-1-napthaldehyde ... إقراء المزيد

2018-09-16 15:07:32 الكلمات المفتاحية Kinetics, Activation energy barrier, solvent effect, base hydrolysis mechanism, Hydroxy-chromen-2-ones,
Kinetics of Base Hydrolysis of Some Chromen-2-one Indicator Dyes in Different Solvents at Different Temperatures
Base hydrolysis of 7-hydroxy-2H-chromen-2-one (HC) and 7-hydroxy-2H-chromen-2-one-4-acetic acid (HCA) in aqueous-methanol and aqueous-acetone mixtures were studied kinetically at temperature range from 283 to 313 K. The activation parameters of the reactions were evaluated and discussed. Moreover, the change in the activation energy barrier of the investigated compounds from water to water-methanol and water-acetone mixtures was estimated from the kinetic data. ... إقراء المزيد

2018-09-13 09:56:15 الكلمات المفتاحية Acid-base hydrolysis, Azomethine, Kinetics, Iron(II) amino acid complexe,
Salts and Structural Effects on the base Catalyzed Hydrolysis of some Novel and Pharmacologically Active Iron (II) Azomethine Amino Acid Complexes.
The effect of salts on the reactivity of base hydrolysis of Fe (II) chelates bis (naphthylidene alanate)(nali), bis (naphthylidene phenylalanate)(nphali), bis (naphthylidene aspartate)(nasi),(naphthylidene histidinate)(nhi), bis (naphthylidene arginate)(nari) has been investigated in aqueous media containing alkali metal halides viz. LiBr, NaCl, KBr, Tetramethylammonium bromide (TMAB), Tetraethylammonium bromide (TEAB) and Tetrabutylammonium bromide (TBAB). The suggested mechanism of the base hydrolysis reaction involves ... إقراء المزيد