Three new polyphosphates were synthesized in good yields by reacting diethylenetriamine with the appropriate phosphate ester in ethanol under acidic conditions. The polyphosphate structures were determined using FT-IR and 1H-NMR spectroscopies, and their elemental compositions were confirmed by EDX spectroscopy. Polyphosphates were added to poly(vinyl chloride) (PVC) at low concentrations to fabricate thin films. The PVC films were irradiated with ultraviolet light for long periods, and the effect of polyphosphates as the photostabilizer was investigated by determining changes in the infrared spectra (intensity of specific functional group peaks), reduction in molecular weight, weight loss, and surface morphology. Minimal changes were seen for PVC films containing polyphosphate compared to that for the blank film. In addition, optical, scanning electron, and atomic force microscopies were used to inspect the surface morphology of films. Undesirable changes due to photodegradation were negligible in PVC films containing additives compared to films containing no additives. In addition, the surfaces were smoother and more homogeneous. Polyphosphates, and in particular ones that contain an ortho-geometry, act as efficient photostabilizers to reduce the rate of photodegradation. Polyphosphates absorb ultraviolet light, chelate with polymeric chains, scavenge radical moieties, and decompose peroxide residues.
Iron-Epoxy composite samples were prepared by added
different weight percentages (0, 5, 10, 15, and 20 wt %) from Iron
particles in the range of (30-40μm) as a particle size. The contents
were mixed carefully, and placed a circular dies with a diameter of
2.5 cm. Different mechanical tests (Shore D Hardness, Tensile
strength, and Impact strength ) were carried out for all samples. The
samples were immersed in water for ten weeks, and after two weeks
the samples were take-out and drying to conducting all mechanical
tests were repeated for all samples. The hardness values increased
when the Iron particle concentration increased while the Impact
strength is not affected by the increasing of Iron particles
c
This study aimed to manufacture an innovative device that enables the player to walk after the operation and improves the functional efficiency through the improvement in the range of motion as well as the improvement in the size of the muscles working on the knee joint. The research, the study population consisted of players with severing the anterior cruciate ligament of the advanced soccer players, and the number of the research sample was (5) injured for the control sample and (5) for the experimental sample in Abu Ghraib Hospital and some rehabilitation centers for a period of six months, and the pre-tests were conducted after two weeks of The cruciate ligament surgery was performed, and the innovative device was used for the e
... Show MoreZinc oxide (ZnO) nanostructures were synthesized through the hydrothermal method at various conditions growth times (6,7 and 8 hrs.) and a growth temperature (70, 90, and 100 ºC). The prepared ZnO nanostructure samples were described using scanning electron microscopy (SEM) and X-ray diffractometer to distinguish their surface morphologies and crystal structures. The ZnO samples were confirmed to have the same crystal type, with different densities and dimensions (diameter and length). The obtained ZnO nanostructures were used to manufacture gas sensors for NO2 gas detection. Sensing characteristics for the fabricated sensor to NO2 gas were examined at different operating temperatures (180, 200, 220, and 240) ºC with a low gas concentrati
... Show MoreBackground: Soft Laser has been advantageous in medical applications and is widely used in clinical practice. It is applied because it doesn’t cause the significant thermal effects or tissue hurt when irradiated. The blood response to low power laser radiation provides information about processes of laser radiation interaction with live creatures. Objective: The aim of the current work was to evaluate the laser-induced changes of in vitro erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC) in patients with breast cancer by irradiating a human blood sample using a green laser and comparing its effects before and after irradiation with the same power density (100mW/c
... Show MoreThe current research aims to determine the requirements of Trends of International Mathematics and Science Study (TIMSS 2019) and to find out the extent to which the content of science textbooks for grades (1-4) in the Sultanate of Oman includes the requirements of (TIMSS 2019). Only the Cognitive Process dimension has been considered when conducting the analysis. The study population includes all science books from the first to the fourth grade for the academic year 2021-2022. The study identified and organized the requirements in the study tool, which is a list of requirements of (TIMSS 2019). After confirming its validity and reliability, the analysis was performed, and data were collected and analyzed statistically using frequencies
... Show MoreIn this paper, three tool paths strategies; iso-planar, helical and adaptive have been implemented to investigates their effect on the mechanical properties of Brass 65-35 formed by single point incremental sheet metal forming process. To response this task, a fully digital integrated system from CAD modeling to finished part (CAD/CAM) for SPIF process has been developed in this paper.
The photo-micrographs shows an identical grain formation due to the plastic deformation of the incremental forming process, change in the grain shape and size was observed. It's found that the adaptive tool path play a significant role to increase the hardness of the formed specimen from (48 to 90 HV) and the grain texture of the formed specimen found a
We studied the changing of structural and optical properties of pure and Aluminum-doped ZnO thin films prepared by thermal evaporation technique on glass substrates at thickness (800±50)nm with changing of annealing temperatures ( 200,250,300 )℃ for one hour. The investigation of (XRD) indicates that the pure and doped ZnO thin films were polycrystalline of a hexagonal wurtzite structure with preferred orientation along (002) plane. The grain size was decreased with doping before annealing, but after annealing the grain size is increasing with the increase of annealing temperature for pure film whereas for the doped films with ratios 1 %, 2 % we found that the grain size is larger than that before annealing. The grain size
... Show More