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.
Aim: To determine the expression of tissue inhibitors of metalloproteinases (TIMP-2) in oral squamous cell carcinoma (OSCC) and the difference in its expression level between positive and negative HPV-16 (human papilloma virus- 16) OSCC patients. Methods: This study was conducted on 33 biopsies obtained from patients with OSCC and 10 normal oral mucosa as controls. In situ hybridization (ISH) was used to investigate the presence of HPV-16, while immunohistochemistry (IHC) was used to estimate the expression level of TIMP-2. Results: The TIMP-2 was expressed in 27 (81.8%) of OSCC sections with no significant difference between its expression level in HPV-16 positive and HPV-16 negative OSCC cases (p=0.058). TIMP-2 was found to be hig
... Show MorePetroleum is one of the most important substances consumed by man at present times, a major energy source in this century, petroleum oils can cause environmental pollution during various stages of production, transportation, refining and use, petroleum hydrocarbons pollutions ranging from soil, ground water to marine environment, become an inevitable problem in the modern life, current study focused on bioremediation process of hydrocarbons contaminants that remaining in the bottom of gas cylinders and discharged to the soil. Twenty-four bacterial isolates were isolated from contaminated soils all of them gram negative bacteria, bacterial isolates screening to investigate the ability of biodegradation of hydrocarbons, these isolates inocula
... Show Moreprotein oxidation through oxidative stress, which represents the overall status of the protein in the cell/tissue. Due to their increased levels of AOPPs were reported during T2DM. The aim of this study was to assess AOPP level in T2DM subjects with foot ulcer (DFU) and explore its correlation with infection. Type 2 diabetic patients (n=108) and healthy subjects (n=25) were enrolled in this study. The T2DM group was subdivided to diabetic patients without complications (n=25) and eighty-three (83) of them have diabetic foot. They were sub- grouped into two groups according to presence Osteomyelitis and abscess, and in reliance on medical analysis of WBC count and CRP. Group of diabetic without superficial or deep ulcer and no osteomyelitis
... Show MoreA spectrophotometric method has been proposed for the determination of two drugs containing phenol group [phenylephrine hydrochloride (PHP) and salbutamol sulphate (SLB)] in pharmaceutical dosage forms. The method is based on the diazotization reaction of metoclopramide hydrochloride (MCP) and coupling of the diazotized reagent with drugs in alkaline medium to give intense orange colored product (?max at 470 nm for each of PHP and SLB). Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. Under the proposed optimum condition, Beer’s law was obeyed in the concentration range of 1-32 and 1-14 ?g mL-1 for PHP and SLB, respectively. The limit of detection (LOD) and l
... Show MoreFree vibration behavior was developed under the ratio of critical buckling temperature of laminated composite thin plates with the general elastic boundary condition. The equations of motion were found based on classical laminated plate theory (CLPT) while the solution functions consists of trigonometric function and a continuous function that is added to guarantee the sufficient smoother of the so-named remaining displacement function at the boundaries, in this research, a modified Fourier series were used, a generalized procedure solution was developed using Ritz method combined with the imaginary spring technique. The influences of many design parameters such as angles of layers, aspect ratio, thickness ratio, and ratio of initial in-
... Show MoreAn efficient networks’ energy consumption and Quality of Services (QoS) are considered the most important issues, to evaluate the route quality of the designed routing protocol in Wireless Sensor Networks (WSNs). This study is presented an evaluation performance technique to evaluate two routing protocols: Secure for Mobile Sink Node location using Dynamic Routing Protocol (SMSNDRP) and routing protocol that used K-means algorithm to form Data Gathered Path (KM-DGP), on small and large network with Group of Mobile Sinks (GMSs). The propose technique is based on QoS and sensor nodes’ energy consumption parameters to assess route quality and networks’ energy usage. The evaluation technique is conducted on two routing protocols i
... Show MoreThe study aimed to evaluate the level of MMP‑2 in acute myeloid leukemia (AML) patients in comparison with that in remission status, and healthy subjects, and to find its correlation with hematologic parameters. This study included sixty newly diagnosed AML patients. Remission status was assessed after induction chemotherapy. The overall survival (OS) was determined after 6 months. The plasma MMP‑2 level was measured at diagnosis by enzyme immunoassay. Twenty‑eight healthy individuals were recruited as a control group. Plasma MMP‑2 was higher in AML patients than in healthy individuals (P = 0.005). The level of MMP‑2 was much higher in the M5 subtype than in the other subtypes (P = 0.0001). There was no statistically significant d
... Show MoreBackground: Color stability of glass ionomers (GIs) could be affected by many factors such as pH and consumption of liquid medications like antibiotics. Most common antibiotics used during childhood are amoxicillin suspension (AM.S) and azithromycin suspension (AZ.S) which have acidic and basic pH respectively. Aim: to evaluate and compare the effect of AM.S and AZ.S on color stability of nano resin-modified GI. Methods: Thirty disc of nano resin-modified glass ionomer (2mm height x 4mm diameter) were divided into three groups (n=10 for each) and independently exposed to AM.S, AZ.S, and artificial saliva (A.S.). Color stability was evaluated in triplicate by VITA Easyshade® before and after three immersion protocols, repeated over
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