Background: This study aimed to compare the mechanical properties between four groups of newly fabricated combination wires according to their method of union, according to the gauges of wires and a comparison were made between them and their originals. Materials and method: A total of 60 stainless steel combination wires were fabricated , divided into four groups according to gauge of wires and their method of union, each of them with 15 samples, the groups were welded (0.016x0.022-0.016 and 0.016x0.022-0.018) and soldered (0.016x0.022-0.016 and 0.016x0.022-0.018), samples were made according to certain parameters which were : for the welded samples: length,weight, duration of pulsation and size of copper electrode tips used; for the soldered samples: length, weight, distaince from the heat source and duration of heat application Results: The descriptive statistics showed that the maximum value for ultimate force and ultimate tensile strength was for the soldered 0.016x0.022+0.018 inches combination wires, while the minimum was for the welded 0.016x0.022+0.016inches wires. Elastic modulus showed higher values for the soldered 0.016x0.022+0.016 and resiliency values for the welded 0.016x0.022+0.016 were the highest. Comparison between combination wires and their originals showed a decrease in the mechanical properties after soldering and welding. Conclusion: Higher gauge wires and soldering method of union showed better mechanical properties than the other groups and both soldering and welding method showed changes in the mechanical properties of the newly fabricated wires when comparing them with their originals.
The physicochemical behaviour of dodecyltrimethylammonium bromide (DTAB) in water and ethanol-water mixture in the presence and absence of ZnSO4 were studied by measuring the conductivity at 298.15 K. The pre-micellar (S1) and post-micellar slopes (S2) were obtained and calculated the degree of dissociation (α) and the critical micelle concentration (cmc). With an increase in ethanol content, the cmc and α of DTAB increased whereas, in the presence of ZnSO4, the cmc and α decreased. By using cmc and α, thermodynamic properties as the standard free energy of micellization ( ) were evaluated. With an increase in ethanol content, the negative values of are decreased indicating less spont
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What distinguishes human rights issues is their importance to the international community and their importance to democratic political regimes, because they are the axis of any political regime that seeks to achieve a successful democratic path and a stable state. So, countries that are interested in human rights try to enshrine those rights and freedoms in their constitutions and reinforce their concepts in their laws and legislations. Not to mention its involvement in international conventions and treaties concerned with human rights and freedoms, and this is what the Sultanate of Oman has worked on and confirm in the provisions of its 1996 constitution and its amendments
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The induced photodegradation of methyl cellulose (MC) films in air was investigated in the absence and presence of aromatic carbonyl compounds(photosenssitizers): 1,4-naphthaquinone (NQ) and benzophenone (BPH) by accelerated weathering tester. The addition of (0.01 wt %) of low molecular weight aromatic carbonyl compounds to cellulose derivatives films(25µm in thickness) enhanced the photodegradation of the polymer films.The photodegradation rate was measured by the increase in carbonyl absorbance. Decreases in solution viscosity and reduction of molecular weight were also observed in the irradiated samples. Changes in the number-average chain scission, the degree of deterioration and in the quantum yield of chain scission values are als
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Summary:This article discusses the topic of phraseological units with the names of wild animals in the Russian and Arabic languages in the aspect of their comparative semantic and cultural analysis, since a comparative analysis of the meanings of phraseological units of the Arabic and Russian languages, detection of coincidences and differences in the compared languages, is an important method for studying linguoculturology, since phraseological units represent a reflection of culture in the language
4-chloro and 4- nitro substituted phenol and aniline incorporated to a carboxylic group of naproxen a well-known non-steroidal anti-inflammatory drug (NSAID) to increase bulkiness were synthesized for evaluation as a potential anti-inflammatory agents with expected COX-2 selectivity. In vivo acute anti-inflammatory activity of these compounds (I-IV) was evaluated in rats using egg-white induced edema model of inflammation in a dose equivalent to (2.5 mg/Kg) of naproxen. All tested compounds produced a significant reduction in paw edema with respect to the effect of propylene glycol 50% v/v (control group). Moreover, compounds I and IV might show higher effect comparable to that of naproxen and to that of compounds II & III whic
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A new series of schiff base and aminothiadiazole derivatives of N- substituted phthalimide (I-VI) were synthesized. In this work, the intermediate 4-(1,3-dioxoisoindolin-2-yl)benzaldehyde compound (I), was formed by reaction of 4-amino benzaldehyde with phthalic anhydride in glacial acetic acid(GAA). A series of Schiff bases (IV-VI) was prepared by the reaction of benzidine with compound (I) in ethanol and presence of GAA as a catalyst to form compound (IV) which react with compound (I) and p-nitro benzyldehyde to give compound (V) and (VI) respectively. A new phthalimide thiosemi-carbazone derivative (ll) was prepared by reaction of compound (l) with thiosemi-carbazide HCl in the presence of equimolar amount of sodium acetate. Fina
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