47 research outputs found
Fear of the Unknown among Normal People, People with Psychological Disorders, and People with Organic Disorders in the Light of Some Demographic Variables
The present paper aimed to determine the fear of the unknown among normal people, people with psychological disorders, and people with organic disorders in the light of some demographic variables. The authors adopted the descriptive-comparative method and developed and applied a three-domain questionnaire to a randomly selected sample of (942) participants. The results showed that the people with psychological disorders suffer from fear of the unknown more than normal people and people with organic disorders at a significance level of (0.05). There were no statistically significant differences between the different categories of psychological disorders (including generalized anxiety disorder, depression, panic attacks, post-traumatic stress disorder, obsessive-compulsive disorder, and phobia) in contrast with the organic diseases, in which cardiac and respiratory diseases were at a greater risk of being afraid of the unknown more than those with diabetes, blood pressure, and thyroid. The paper recommends conducting further studies on the concept of fear of the unknown in the Arab countries and adopting fear of the unknown as a psychological intervention for people with psychological disorders and people with cardiac and respiratory diseases
Impact of free radicals on the electrostatic charging tendency of transformer oils
In this contribution, the influence of free radical concentration on the electrostatic charging tendency (ECT) of aged mineral oils is reported. A free radical reagent, 2,2 diphenyl-1-picrylhydrazyl, is used to assess the relative concentration of free radicals. Prior to the ECT measurement, the oil samples were subjected to various stresses (corona discharges, multiple arcs or local overheating). Different ASTM standards were considered to assess the physicochemical properties before and after stress applications. It is found that free radicals affect the ECT. The theoretical premises that, free radicals may contribute to the ECT, are experimentally confirmed under laboratory conditions. The reason why this information is important is that ECT can significantly affect partial discharge inception in in-service transformers
Actions of bisnucleophiles on (E)-3-[3-(2-Hydroxyaryl)-3-oxoprop-1-en-1-yl]chromones: versatile transformations into oxygen-and nitrogen-containing heterocycles
The transformations of (E)-3-[3-(2-hydroxyaryl)-3-oxoprop-
1-en-1-yl]chromones in the presence of methylhydrazine and aromatic
bisnucleophiles are described. The reactions generally lead to chromone
ring transformation via pyrone ring-opening and heterocyclization
to give novel diazoles and (Z)-3-aminomethylenechromanones, respectively.
Piperazine catalyzes chromanone ring closure of the starting
substrate to afford chromone–chromanone dyads
Synthesis and Ring Transformation of Oxygen and Nitrogen Spiro Bisheterocycles
A facile and rapid access to bridgehead oxygen-and nitrogen-containing spiro bisheterocycles is reported. It involves a one-pot spiro-to-spiro ring transformation of the key spiro[chromanone-hydantoin] compounds into new substituted spiro [hydantoin-diazole], spiro [hydantoin-isoxazole], spiro [hydantoin-diazepine], spiro [hydantoinoxazepine], and spiro [hydantoin-benzodiazepine] upon reaction with appropriate bisnucleophilic agents. The hydantoin cycle is preserved during these chemical reactions affording the spiro bisheterocycles in optimal yields (42-71%). This relevant spiro-to-spiro ring transformation was confirmed by NMR and single-crystal X-ray diffraction studies
A One-Pot Diastereoselective Synthesis of 2-[Aryl(hydroxy)methyl]-6-methyl-2H-furo[3,2-c]pyran-3,4-diones: Crystallographic Evidence for the Furanone Ring Closure
Novel furopyran-3,4-dione-fused heterocycles have been obtained by a one-pot reaction of -brominated dehydroacetic acid and benzaldehydes under organobase conditions. The prepared 2-[aryl(hydroxy)methyl]-6-methyl-2H-furo[3,2-c]pyran-3,4-diones were fully characterized by 2D NMR spectroscopy and supported by single-crystal X-ray analysis to unequivocally prove the furan-3-one five-membered ring-closure mechanism instead of the dihydroflavanon-3-ol six-membered cyclization which has recently been proposed in the literature
1,3-Dicyclohexylimidazolidine-2,4,5-trione
The title compound, C15H22N2O3, has been isolated as a by-product of an oxidative cleavage of the C—C bond linking two five-membered rings of 1,3-dicyclohexyl-5-(3-oxo-2,3-dihydrobenzofuran-2-yl)imidazolidine-2,4-dione. Individual molecular units are engaged in weak C=O⋯C=O interactions [O⋯C = 2.814 (10) and 2.871 (11) Å], leading to the formation of supramolecular chains which close pack, mediated by van der Waals contacts, in the bc plane
One-Pot Synthesis of Novel Highly Functionalized Furan-Based Polyphenolics
Novel, highly functionalized furan-based polyphenolics were prepared. The employed methodology involves a one-pot 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) catalyzed 1,4-conjugate addition of 1,3-dicarbonyl compounds on 3-bromochromones, furan heterocyclization, and chromanone ring opening
Solid fermentation of wheat bran for hydrolytic enzymes production and saccharification content by a local isolate Bacillus megatherium
Planification d'enchaînement de cursus dans un univers d'objets d'apprentissage.
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