This study aims to predict the organic pollution produced from the presence of some polycyclic aromatic hydrocarbons (PAHs) and determination it's concentrations (µg/L , ppb) in Tigris river water by a collection twenty-seven water samples from a selected three stations with nine sampling sites and three depths of water (5 cm , 2 m and 4 m) each site for 4.6 km distance of a geographic studied area which is located between the ( Al-Senak and AL-Sarrafiah bridges ) at Baghdad city – Iraq on May, 2012. The geographic location was determined with a Global Positioning System (GPS) and Geographic Information System (GIS) software program. The concentrations of fourteen components (PAHs) were performed using the reverse phase of high performance liquid chromatography (RP-HPLC) technique. Samples were chemically treated using liquid-liquid extraction method , filtered , extracted , dried , evaporated and pre-concentrated in order to be ready for analysis . The determined concentrations of (PAHs) for the studied area did exceed the criteria values proposed by the International Environmental Organizations like American Environment Protection Agency (U.S-EPA) and British Health Agency (BHA) . The results were showed that the maximum values of the total concentrations (PAHs) were found to be 228 µg/L (5 cm depth , site F, Medicine city station , Al-Resafa bank) , 192.1 µg/L (2 m depth , site D , Medicine city station , Al-Karkh bank) and 80.1 µg/L (4 m depth , site D , Medicine city station , Al-Karkh bank) , while the minimum values were found to be be 51.2 µg/L (5 cm depth , site I, Al-Sarrafia bridge station , Al-Resafa bank) , 33.4 µg/L (2 m depth , site G , Al-Sarrafia bridge station , Al-Karkh bank) and 4.8 µg/L (4 m depth , site G , Al-Sarrafia bridge station , Al-Karkh bank) .
The cost-effective removal of heavy metal ions represents a significant challenge in environmental science. In this study, we developed a straightforward and efficient reusable adsorbent by amalgamating chitosan and vermiculite (forming the CSVT composite), and comprehensively investigated its selective adsorption mechanism. Different techniques, such as Fourier-transform infrared spectroscopy (FTIR), zeta potential analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer, Emmett, Teller (BET) analysis were employed for this purpose. The prepared CSVT composite exhibited a larger surface area and higher mesoporosity increasing from 1.9 to 17.24 m2/g compared to pristine chitosan. The adsorption capabilities of the
... Show MoreThis study aims to fabricate and assess the β-tricalcium phosphate (β-TCP) bioactive ceramic coat layer on bioinert ceramic zirconia implants through the direct laser melting technique by applying a long-pulsed Nd:YAG laser of 1064 nm. Surface morphologies, adherence, and structural change in the coatings were evaluated by optical microscopy, field emission scanning electron microscope, hardness, and x-ray diffractometer. The elastic modulus (EM) of the coating was also determined using the nanoindentation test. The quality of the coating was improved when the laser power was 90 W with a decrease in the scan speed to 4 mm s−1. The chemical composition of the coat was maintained after laser processing; also, the Energy Dispersive
... Show MoreA Schiff base ligand (L) was synthesized via condensation of
A Schiff base ligand (L) was synthesized via condensation of
New polymer blend with enhanced properties was prepared from (80 %) epoxy resin (Ep), (20%) unsaturated polyester resin (UPE) as a matrix material. The as-obtained polymer blend was further reinforced by adding Sand particles of particle size (53 μm) with various weight fraction (5, 10, 15, 20 %). Thermal conductivity and sorption measurements are performed in order to determine diffusion coefficient in different chemical solutions (NaOH, HCl) with concentration (0.3N) after immersion for specific period of time (30 days). The obtained results demonstrate that the addition of sand powder to (80%EP/20%UPE) blend leads to an increase of thermal conductivity, with an optimum/minimum diffusion coefficient in (HCl)/(NaOH), respectively.
Skeletal Class II malocclusion is commonly treated with functional appliances, but bulkiness and discomfort usually affect the compliance. Modifications of these appliances using clear thermoplastic materials could improve comfort and esthetics; though clinical evidence remains limited.
To assess the clinical effectiveness of a Modified Twin Block (MTB) appliance, fabricated from 2 mm biocompatible polyethylene terephthalate modified with Glycol