The centers of cities and historical quarter are exposed to a severe threat to the values of the physical and legal urban environment as a result of the value deterioration and the emergence, emergence and spread of new values on the intellectual and urban context, which generates the loss of the urban environment for its spatio-temporal continuity, flexibility, adaptation and continuity, and thus urban obsolescence, Hence the problem of the research in “the lack of comprehensiveness of studies on the phenomenon of urban obsolescence and its impact on the decline in the values of the quality of the built environment in historical quarters”, and accordingly the goal of the research was determined in “building a theoretical framework for the phenomenon of urban obsolescence and exploring the impact of this phenomenon on the quality of the built environment of historical quarters”, The research assumes the multiplicity and varying levels of urban obsolescence in the historical quarters, which affects the quality of the assets of these quarters. The research aims to provide this knowledge by adopting the descriptive analytical approach for a number of urban studies to reach the identification of the main vocabulary related to the phenomenon of urban obsolescence and to extract the most important definitions and causes. This is reflected in the quality levels of urban assets in them.
This work aimed to use conventional PCR to identify Salmonella spp. that were isolated from diarrheal children and healthy and diarrheic dogs based on four virulence genes, hilA, stn, spvR, and marT. Sixteen Salmonella isolates including: 9 isolated from children's diarrhea from three species (S. Typhimurium, S. Enteritidis, S. Typhi) and seven isolated from dogs including (S. Typhimurium, S. Enteritidis, S. Muenchen), were identified primarily by several methods. The PCR products of the 16S rRNA gene were sequenced and examined using BLAST analysis to find differences and similarities between these Iraqi isolates and already-known global strains in order to construct the phylogenetic tree of S.
... Show MoreBackground: This in vitro study compares a novel calcium-phosphate etchant paste to conventional 37% phosphoric acid gel for bonding metal and ceramic brackets by evaluating the shear bond strength, remnant adhesive and enamel damage following water storage, acid challenge and fatigue loading. Material and Methods: Metal and ceramic brackets were bonded to 240 extracted human premolars using two enamel conditioning protocols: conventional 37% phosphoric acid (PA) gel (control), and an acidic calcium-phosphate (CaP) paste. The CaP paste was prepared from β-tricalcium phosphate and monocalcium phosphate monohydrate powders mixed with 37% phosphoric acid solution, and the resulting phase was confirmed using FTIR. The bonded premolars were exp
... Show MoreNumerical investigation has been carried out on heat transfer and friction factor characteristics of copper-water nanofluid flow in a constant heat-fluxed tube with the existence of new configuration of vortex generator using Computational Fluid Dynamics (CFD) simulation. Two types of swirl flow generator: Classical twisted tape (CTT) and Parabolic-cut twisted tape (PCT) with a different twist ratio (= 2.93, 3.91 and 4.89) and different cut depth (= 0.5, 1.0 and 1.5 cm) with 2% and 4% volume concentration
... Show MoreIn this work, mesoporous silica SBA-15 was prepared and functionalized with amine groups (i.e., NH2) to form NH2/SBA-15. The curcumin (CUR) was encapsulated into the surface and pore of NH2/SBA-15 to create CUR@NH2/SBA-15 as an efficient carrier in drug delivery systems (DDSs). The three samples (i.e., SBA-15, NH2/SBA-15, and CUR@NH2/SBA-15) were characterized. The study investigated the effect of the carrier dose, initial CUR concentration, pH, and contact time on the CUR loading efficiency (DLE%) via adsorption. The best DLE% for the SBA-15 and NH2/SBA-15 were found to be 45% and 89.7%, respectively. The Langmuir isotherm had a greater correlation coefficient (R2) of 0.998 for SBA-15. A pseudo-secondorder kinetic model seemed to fit well
... Show MoreSynthesis of a new class of Schiff-base ligand with a tetrazole moiety to form polymeric metal complexes with CoII, NiII, ZnII, and CdII ions has been demonstrated. The ligand was synthesised by a multi-steps by treating 5-amino-2-chlorobenzonitrile and cyclohexane -1,3-dione, the 5,5'-(((1E,3E)-cyclohexane-1,3-diylidene)bis(azanylylidene))bis(2-chlorobenzonitrile) was obtained. The precursor (M) was prepared from the reaction 5,5'-(((1E,3E)-cyclohexane-1,3-diylidene)bis(azanylylidene))bis(2-chlorobenzonitrile) with NaN3 to obtained (1E,3E)-N1,N3-bis(4-chloro-3-(1H-tetrazol-5-yl)phenyl)cyclohexane-1,3-diimine (N). By reacting the precursor (M) with CS2
... Show MoreIn this research, the study effect of additive titanium dioxide powder (TiO2) as a lone composite ( Ep+TiO2) and a mixture of (TiO2) and silicon oxide (SiO2), ( Ep+ TiO2+SiO2)as a hybrid composite on the mechanical and physical properties for epoxy coating. Thescompsiteswere prepared by (Hand Lay- the molding) method. The samples were tested for compressive strength, surface hardness, modulus of elasticity, thermal conductivity and diffusion coefficient, from the results obtained showed improvement in mechanical properties after adding ceramic powders, as the alone composite (EP+ TiO2) had the highest compressive strength ( 53.738 ) ᴍPa, the hybrid composite ( EP+TiO2 +SiO2 ) had the
... Show MoreContamination of surface and groundwater with excessive concentrations of fluoride is of significant health hazard. Adsorption of fluoride onto waste materials of no economic value could be a potential approach for the treatment of fluoride-bearing water. This experimental and modeling study was devoted to investigate for the first the fluoride removal using unmodified waste granular brick (WGB) in a fixed bed running in continuous mode. Characterization of WGB was carried out by FT-IR, SEM, and EDX analysis. The batch mode experiments showed that they were affected by several parameters including contact time, initial pH, and sorbent dosage. The best values of these parameters that provided maximum removal percent (82%) with the in
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