In this work, varying compositions of SiO2 micro filler were added
with the Polyvinyl Chloride (PVC) and samples have been prepared
using film casting technique. The results have been analyzed and
compared for PVC samples with (1 wt%, 3 wt%, 5 wt% and 10 wt%)
SiO2 micro filler. Mechanical characteristics such as tensile strength,
elongation at break and Young`s modulus were measured for all the
samples, where the tensile strength was increased from 8.39 Mpa for
purified PVC to 16 Mpa for 3% SiO2/PVC composite. Also, thermal
conductivity measurement values illustrated that composite materials
have a good thermal insulation at 10 wt. %, thermal conductivity was
decreased from 0.1684 W/m. K for PVC to 0.1310W/m. K at 10%
SiO2/PVC composite. Absorptivity test was also carried out for these
samples, the results of this study proved that PVC and SiO2-PVC
composites have low diffusion coefficients ranging from (10-13- 10-10
m2/s). Similarly, the dielectric properties like dielectric constant, loss
factor, resistance, and volume resistivity were performed; the
dielectric constant was increased from 2.1039 for PVC to 3.658 for
3% SiO2/PVC composites, while the dielectric loss factor was
decreased from 0.0144 for PVC to 0.0137 for 5%SiO2/PVC
composite. The values of resistance were increased from
17259.99(Ω) for purified PVC to 29185.75(Ω) for 10% SiO2/PVC
composites. Volume resistivity was increased from 0.3794 x109 (Ω.
cm) for PVC to 0.5179x109 (Ω. cm) for 10% SiO2/PVC composites.
FTIR spectroscopy was employed for all PVC-composite samples
and its results were investigated, there are systematic increases in
absorbance intensity spectra with SiO2 ratios attributed to good
distribution of inorganic fillers (Symmetric increases). The
microstructure and morphology of the prepared samples were
investigated by using optical microscope. It can be observed that, the
samples with (3% SiO2/PVC) are glossy and smooth without
agglomeration of (SiO2) particles in (PVC) matrix. The results
demonstrate that PVC-composite films prepared in this study show
promising potential to achieve good materials for plastic packaging
applications.
Background: The apical seal is the single most important factor in determining the success of surgical endodontics, the aim of this study was to compare the sealing ability of Mineral Trioxide Aggregate in three different cavity designs. Materials and Methods: Thirty extracted human single-rooted teeth were divided into three groups of ten teeth per group, a retrograde cavity preparation was carried out using a low speed handpiece and round bur with parallel walls in the first group, ultrasonic retrotip and unit in the second group and a low speed handpiece with a carbide inverted cone bur with undercuts in the third group, all the cavities were filled with MTA. microleakage was measured by dye penetration technique using methylene blue. Re
... Show MoreAn investigation of the quadrupole deformation of Kr, Sr, Zr, and Mo isotopes has been conducted using the HFB method and SLy4 Skyrme parameterization. The primary role of occupancy of single particle state 2d5/2 in the existence of the weakly bound structure around N=50 is probed. Shell gaps are performed using a few other calculations for the doubly magic number 100Sn using different Skyrme parameterizations. We explore the interplays among neutron pairing strength and neutron density profile in two dimensions, along with the deformations of 100Sn.
During recent years, there has been an increasing interest in the investigation of the cytokines roles in pathogenesis of cancer, thus the study aimed at evaluating the level of tumor necrosis factor-alpha(TNF-?) in sera of Iraqi multiple myeloma (MM) patients. Beta 2-microglobulion (?2-m) was assessed to determine if there was any association between this cytokine and the level of ?2- m, as the latter is related to the stage of the disease. In addition, the age and gender were also taken into consideration. Furthermore, we investigated the relationship between IgG and TNF-? in sera of patients. 49 Iraqi patients (27 males and 22 females).The patients were also divided into two groups: the first group included (17) patients who were
... Show MoreThe duty of care is the essence of the error of negligence under the English legal system, and without it, responsibility for negligence cannot be judged, regardless of the extent of the damage incurred. contained in English law. In view of the importance of proving the existence of the duty of care on the defendant so that it is possible to judge his responsibility for negligence, the need arises to find a general principle to which the defendant is subject in order to decide whether he owes the plaintiff with the duty of care and therefore responsible for the negligence, and this is what we will explain in the research topic the study.
Acinetobacter baumannii (A. baumannii) is a major opportunistic nosocomial pathogen, mostly resistant to several groups of antibiotics. Colistin is now used as a last-line treatment for isolates that are highly resistant. The purpose of this study is to identify the importance of LptD; which is involved in the translocation of LPS from the inner membrane to the outer membrane in compartment with LptA and LptC of A. baumannii and its indispensable role as a virulence factor, and the efficiency of colistin as a monotherapy. In the current research, two isolates of A.baumannii were used, the local isolate HHR1 isolated from urine sample and the global strain ATCC 17904, and three antibiot
... Show MoreAfter 2003, Iraq witnessed new challenges represented by the predominance of sectarian discourses, hatred and extremism at the expense of moderate political discourse and the predominance of sub-affiliations and external agendas at the expense of national affiliation, which led to the creation of an unsafe or stable environment dominated by the character of violence and terrorism. Moderate discourse would work to fuse sub-affiliations into one melting pot in which it would be the first loyalty to the homeland and not to the tribe, party or sect... Etc., and this in turn will contribute to promoting peaceful coexistence between the various other sub-affiliations within the framework of one community construction
Background: Cystinosis is a rare autosomal recessive lysosomal storage disease with high morbidity and mortality. It is caused by mutations in the CTNS gene that encodes the cystine transporter, cystinosin, which leads to lysosomal cystine accumulation. It is the major cause of inherited Fanconi syndrome, and should be suspected in young children with failure to thrive and signs of renal proximal tubular damage. The diagnosis can be missed in infants, because not all signs of renal Fanconi syndrome are present during the first months of life. Elevated white blood cell cystine content is the cornerstone of the diagnosis. Since chitotriosidase (CHIT1 or chitinase-1) is mainly produced by activated macrophages both in normal and inflammator
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