Papers by Ahmad Al-ajlouni
International journal of technology in education, Jan 15, 2022
Following the 2019 coronavirus (COVID-19) pandemic, the role of distance learning is to substitut... more Following the 2019 coronavirus (COVID-19) pandemic, the role of distance learning is to substitute conventional teaching methods worldwide and to keep the education process tenacious. The purpose of this study was to explore the impact of distance learning in science education at Jordan University of Science and Technology (JUST) during the COVID-19 pandemic. This was a mixedmethods study that utilized quantitative descriptive-analytical approaches. Twenty-eight science faculty members at JUST were eligible to participate. A survey questionnaire adapted from an Irish national survey to explore the impact of the COVID-19 crisis school closures on teaching and learning science was used. Findings from this study show a significant impact of distance teaching on science education. The participants reported many obstacles and challenges, including internet connection issues and lack of experience with the new technology and teaching strategies. Moreover, 75% of the participants reported that technical problems were the most significant among other obstacles. The advantages of distance learning were also explored in this study; the participants reported gaining new techniques and teaching skills. However, the majority of the participants reported a preference for the traditional methods over distance learning and advocated for taking advantage of blended learning to improve science teaching.
Epoxidation of olefins by hydrogen peroxide as catalyzed by methylrhenivim trioxide 1 Oxidation o... more Epoxidation of olefins by hydrogen peroxide as catalyzed by methylrhenivim trioxide 1 Oxidation of 1,2-diols, phenols and hydrogen peroxide by pentaaquaoxochromium(IV) ion 3 Dissertation organization 5 CHAPTER I. THE EPOXIDATION OF STYRENES BY H2O2 AS CATAYLZED BY METHYLRHENIUM TRIOXIDE
ABSTRACT The effect of β-cyclodextrin on the catalytic stability and reactivity of methylrhenium ... more ABSTRACT The effect of β-cyclodextrin on the catalytic stability and reactivity of methylrhenium trioxide (MTO), CH3ReO3, which has been used for activation of hydrogen peroxide toward oxidation and epoxidation reactions, was studied using UV–Vis spectrophotometery. The stability and reactivity of the new catalytic system (MTO/β-CD) to activate H2O2 toward oxidation of indigo blue dye were investigated in basic media. Furthermore, effects of inclusion stoichiometry, temperature and concentrations of hydrogen peroxide on the stability and reactivity of the MTO/β-CD system were investigated. The formation of the inclusion complex between MTO and β-CD was confirmed experimentally using the changes in the UV–Vis absorption spectra. The results of this study demonstrate that the complexation process was better guaranteed when the amount of β-CD is higher than that of MTO, using a 1:2molar ratio of MTO:β-CD enhances both the activity and stability of the catalyst. The results showed that the stability of the catalytic system was enhanced in presence of β-CD with maintaining good reactivity of the MTO even in the presence of high concentration of NaOH. The changes of thermodynamic activation parameters (ΔH≠ and ΔS≠) for the oxidation reaction of indigo with H2O2 catalyzed by MTO/β-CD system were determined on the basis of the experimental data. KeywordsCatalysis–Rhenium complexes–Inclusion complex–Oxidation of indigo dye–Activation of hydrogen peroxide
Environmental …, 2007
Water with high nitrate concentration (NO 3 − − , indicating the influence of human activities. T... more Water with high nitrate concentration (NO 3 − − , indicating the influence of human activities. This study has shown that there is a strong correlation between the nitrate concentration and the wastewater effluents as a source of pollution.
Groundwater for Sustainable Development
ChemInform
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Water Quality Monitoring and Assessment, 2012
Journal of the Chemical Society, Dalton Transactions, 2000
Hyponitrites, salts of the weak acid HON NOH, hyponitrous acid, react, in aqueous solution (pH ... more Hyponitrites, salts of the weak acid HON NOH, hyponitrous acid, react, in aqueous solution (pH 48), with an array of inorganic oxidants. With the high potential reagents Br 2 and [Fe(bipy) 3 ] 3+ in excess, conversion is mainly to nitrate, whereas with I 2 and [IrCl 6 ] 2− , ...
Research on Chemical Intermediates, 1998
Aqueous solutions of indium(III) undergo le-reductions by Sm(II) (E ~-1.55 V) and by Yb(ll) (-1.0... more Aqueous solutions of indium(III) undergo le-reductions by Sm(II) (E ~-1.55 V) and by Yb(ll) (-1.05 V), but not by U(III) (-0.52 V). The facile and irreversible reduction, by In+,q, of Ru(NH3)63 § (E ~ +0.067 V) at reagent concentrations near 10-3 M implies a potential more negative than-0.23 V for In(II,l) and, in conjunction with the known value of-0.44 V for In(III,I), a complementary potential less negative than-0.65 V for In(Ill,II). These observations, taken together, support leindium potentials E~ V and E~ V.
Organometallics, 2009
The oxidation of η 5-cyclopentadienyl(methyl)(tricarbonyl)molybdenum(II) (1) with excess tertbuty... more The oxidation of η 5-cyclopentadienyl(methyl)(tricarbonyl)molybdenum(II) (1) with excess tertbutylhydroperoxide (TBHP) initially yields η 5-cyclopentadienyl(methyl)(dioxo)molybdenum(VI) (2), which further reacts with TBHP, forming η 5-cyclopentadienyl(methyl)(oxo)(peroxo)molybdenum(VI) (3). The solid-state structure of 3 has been determined by single-crystal X-ray crystallography. Detailed kinetic studies have been carried out on the oxidation of 1 with TBHP as an oxidizing agent and on the catalytic activities of the resulting oxidation products, 2 and 3, in olefin epoxidation. In the absence of oxidant, neither of the molybdenum species is able to transfer an O-atom to an olefin. However, both Mo(VI) species act as catalysts for the epoxidation of olefins with TBHP through the formation of active intermediates. It has been found that compound 3 reacts with excess TBHP to give an active intermediate, which exists in equilibrium with the catalyst precursor 3 with a K eq close to 1. This intermediate is slowly formed in a reversible initial step. It reacts rapidly with an olefin, while it decomposes in the absence of olefin. Furthermore, the kinetic results indicate the formation of another active intermediate, originating from 2, that is 3-5 times more active in epoxidation catalysis than the active intermediate formed from 3. A mechanistic scheme is proposed, based on the kinetic results.
Journal of the American Chemical Society, 1995
ABSTRACT Methylrhenium trioxide, CHâReOâ, catalyzes the oxidation of styrenes by hydrogen peroxid... more ABSTRACT Methylrhenium trioxide, CHâReOâ, catalyzes the oxidation of styrenes by hydrogen peroxide. Kinetic studies by three methods were carried out in acidic CHâCN/HâO (1:1 v/v) solutions. The catalytically-active species are the mono-peroxide, CHâRc(O)â(Oâ), A, and the bis-peroxide, CHâRe(O)(Oâ)â, B, which epoxidize a given styrene at a similar rate. The rate constants are relatively insensitive to steric hindrance, but increase with the nucleophilicity of the styrene, electron-donating groups on the olefinic carbons or on the aromatic ring enhancing the rate. The rate constants for meta- and para-substituted styrenes follow a linear Hammett relationship; correlation with Ï{sup +} gave Ï = -0.93 {+-} 0.05. In CDâCN, epoxides were observed by ¹H NMR spectroscopy. cis-β-Methylstyrene and trans-β-methylstyrene led to the cis epoxide and the trans epoxide, respectively. In acidic CHâCN/HâO, the major products were 1,2-diols. In some cases C-C bond cleavage products were also observed, the extreme case being β-methoxystyrene where the C-C bond was completely cleaved to yield benzaldehyde, formaldehyde, and methanol. 32 refs., 7 figs., 2 tabs.
Journal of Organometallic Chemistry, 1987
ABSTRACT The reaction of organoiron sulfanes, (μ-Sx)[FeCp(CO)2]2 (x = 3, 4) with LiBEt3H at −97°C... more ABSTRACT The reaction of organoiron sulfanes, (μ-Sx)[FeCp(CO)2]2 (x = 3, 4) with LiBEt3H at −97°C gives the anionic species [Cp(CO)2FeSx]− (x = 1, 2 or 3). The solution containing the anionic species reacts with acid chlorides RCOCl to give [FeCp(CO)2(SCOR)], which contain the S-bonded monothiocarboxylate ligand. The same products and [FeCp(CO)2Cl] were obtained from the reaction of (μ-Sx)-[FeCp(CO)2]2 (x = 3,4) and RCOCl at room temperature.
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Papers by Ahmad Al-ajlouni