Experimental enhancement for electric properties of polyethylene nanocomposites under thermal conditions

Polymer properties can be experimentally tailored by adding small amounts of different nanoparticles for enhancing their mechanical, thermal and electrical properties. The work in this paper investigates enhancing the electric and dielectric properties of Low Density Polyethylene (LDPE), and High Density Polyethylene (HDPE) polymer materials with cheap nanoparticles. Certain percentages of clay and fumed silica nanoparticles are used to enhance electric and dielectric properties of polyethylene nanocomposites films. By using the Dielectric Spectroscopy; the electric and dielectric properties of each polyethylene nanocomposites have been measured with and without nanoparticles at various frequencies up to 1kHz under different thermal conditions (20°C and 60°C). And so, we were successful in specifying the optimal nanoparticles types and their concentrations for the control of electric and dielectric characterization

Experimental Dielectric Measurements for Cost-fewer Polyvinyl Chloride Nanocomposites

Polymer nanocomposites possess promising high performances as engineering materials, if they are prepared and fabricated properly. In this research, it has been processed samples of nanocomposite polymers as electrical insulating materials for application on the electric power cables by using the latest techniques of nanotechnology. This paper has been investigated enhanced dielectric and electrical properties of Polyvinyl chloride PVC as matrix have shown that trapping properties are highly modified by the presence of costless nanofillers clay and fumed silica. An experimental work for dielectric loss and capacitance of the new nanocomposite materials have been investigated and compared with unfilled industrial materials. It is found that a good correlation exists in respect of capacitance and dielectric loss values measured with percentage of nanofillers. Thus, it has been investigated the influence of costless nanofillers material and its concentration on dielectric properties of industrial polymers-based composite systems. A comparative study is performed between the unfilled base polymers, the systems containing one type of nanoparticles clay or fumed silica inside the host polymer with various concentrations

Thermal experimental analysis for dielectric characterization of high density polyethylene nanocomposites

The importance of nanoparticles in controlling physical properties of polymeric nanocomposite materials leads us to study effects of these nanoparticles on electric and dielectric properties of polymers in industry In this research, the dielectric behaviour of High-Density Polyethylene (HDPE) nanocomposites materials that filled with nanoparticles of clay or fumed silica has been investigated at various frequencies (10 Hz-1 kHz) and temperatures (20-60°C). Dielectric spectroscopy has been used to characterize ionic conduction, then, the effects of nanoparticles concentration on the dielectric losses and capacitive charge of the new nanocomposites can be stated. Capacitive charge and loss tangent in high density polyethylene nanocomposites are measured by dielectric spectroscopy. Different dielectric behaviour has been observed depending on type and concentration of nanoparticles under variant thermal conditions

Innovative earthing systems for electric power substations using conductive nanoparticles

The earthing system is very important to safe human’s lives and protect power system from normal and abnormal faults. High soil resistivity regions is the main problem of installation the earthing systems in electric power substations to pass the current through the earth's surface. This paper has been overcome on high soil resistivity regions by penetrating conductive nanoparticles to have extremely low grounding resistance. Moreover, it has been succeeded to examine the methodology of the proposed Nano-Tech earthing systems in case of single rods, multiple rods and grids. Also, it has been defined optimal types and concentrations of nanoparticles for Nano-Tech grounding system to provide excellence protection for electrical substations with respect to built beneath of soil where substation is located. A comparative study has been discussed and analyzed the results of traditional and nanotechnology grounding systems

Predictable Models and Experimental Measurements for Electric Properties of Polypropylene Nanocomposite Films

This paper processed and characterized cost-fewer polypropylene (PP) nanocomposite films; an experimental work has been investigated for studying the electric properties of the new nanocomposite materials and compared with unfilled industrial materials in a frequency range up to 1 kHz. A small addition of nanoparticles (clay, and fumed silica) to polypropylene showed appreciable improvement in the electric reactance and conductance at different frequency up to 1kHz, in addition, an  electric spectroscopy has been measured the electric properties of polypropylene with and without nanoparticles under variant temperatures (20°C, and 60°C). Cambridge Engineering Selector (CES) program were carried out the electrical/mechanical predictable models for the suggested materials. Finally, this paper leads to synthesize electrical insulating polypropylene nanocomposite films where the electrical properties are properly maintained in order to achieve more cost-effective, energy-effective and hence environmentally better materials for the electrical insulation technology

Design modern structure for heterojunction quantum dot solar cells

This paper proposal new structure for improving the optical, electrical characteristics and efficiency of 3rd generation heterojunction quantum dot solar cell (HJQDSC) (ITO/CdS/QDPbS/Au) model by using the quantum dot window layer instead of bulk structure layers cell. Also, this paper presents theoretically analysis for the performance of the proposal HJQDSC (ITO/QDCdS/QDPbS/Au) structure. The new design structure was applied on traditional (SnO2/CdS/CdTe/Cu) and (ZnO/CdS/CIGS/Mo) thin film solar cells which based on sub-micro absorber layer thickness models by replacing the bulk CdTe, CIGS absorber layers and CdS window layer with quantum dot size materials to achieve higher efficiency with lesser usage layer material. Also, it has been studied the effect of using semiconductors layers in quantum dots size on electric and optical properties of thin film solar cells and the effect of window and absorber layers quantum dots radii on the performance of solar cells. Finally, a thermal efficiency analysis has been investigated for explaining the importance of new structure HJQD solar cells

Materials Selection, Synthesis, and Dielectrical Properties of PVC Nanocomposites

Materials selection process for electrical insulation application was carried out using Cambridge Engineering Selector (CES) program. Melt mixing technique was applied to prepare polyvinyl-chloride- (PVC-) nanofumed silica and nanomontmorillonite clay composites. Surface analysis and particles dispersibility were examined using scanning electron microscope. Dielectrical properties were assessed using Hipot tester. An experimental work for dielectric loss of the nanocomposite materials has been investigated in a frequency range of 10 Hz–50 kHz. The initial results using CES program showed that microparticles of silica and clay can improve electrical insulation properties and modulus of elasticity of PVC. Nano-montmorillonite clay composites were synthesized and characterized. Experimental analyses displayed that trapping properties of matrix are highly modified by the presence of nanofillers. The nanofumed silica and nanoclay particles were dispersed homogenously in PVC up to 10% wt/wt. Dielectric loss tangent constant of PVC-nanoclay composites was decreased successfully from 0.57 to 0.5 at 100 Hz using fillers loading from 1% to 10% wt/wt, respectively. Nano-fumed silica showed a significant influence on the electrical resistivity of PVC by enhancing it up to 1 × 1011 Ohm·m

Ultra-optical characterization of thin film solar cells materials using core/shell absorber layer

This paper investigates on new design of heterojunction quantum dot (HJQD) photovoltaics solar cells CdS/PbS that is based on quantum dot metallics PbS core/shell absorber layer and quantum dot window layer. It has been enhanced the performance of traditional HJQD thin film solar cells model based on quantum dot absorber layer and bulk window layer. The new design has been used sub-micro absorber layer thickness to achieve high efficiency with material reduction, low cost, and time. Metallics-semiconductor core/shell absorber layer has been succeeded for improving the optical characteristics such energy band gap and the absorption of absorber layer materials, also enhancing the performance of HJQD ITO/CdS/QDPbS/Au, sub micro thin film solar cells. Finally, it has been formulating the quantum dot (QD) metallic cores concentration effect on the absorption, energy band gap and electron-hole generation rate in absorber layers, external quantum efficiency, energy conversion efficiency, fill factor of the innovative design of HJQD cells

Performance comparison of selection nanoparticles for insulation of three core belted power cables

This paper presents an investigation on the enhancement of electrical insulations of power cables materials using a new multi-nanoparticles technique. It has been studied the effect of adding specified types and concentrations of nanoparticles to polymeric materials such as PVC for controlling on electric and dielectric performance. Prediction of effective dielectric constant has been done for the new nanocomposites based on Interphase Power Law (IPL) model. The multi-nanoparticles technique has been succeeded for enhancing electric and dielectric performance of power cables insulation compared with adding individual nanoparticles. Finally, it has been investigated on electric field distribution in the new proposed modern insulations for three-phase core belted power cables. This research has focused on studying development of PVC nanocomposite materials performance with electric field distribution superior to the unfilled matrix, and has stressed particularly the effect of filler volume fraction on the electric field distribution

Impact of Tactile Stimulation on Neurobehavioral Development of Premature Infants in Assiut City

Objective: To assess impact of tactile stimulation on neurobehavioral development of premature infants in Assiut City. Design: Quasi-experimental research design. Setting: The study was conducted in the Neonatal Intensive Care Unit at Assiut University Children Hospital, Assiut General Hospital, Health Insurance Hospital (El-Mabarah Hospital) and El-Eyman for Gynecology and Obstetric Hospital. Subjects: The study subjects included a convenient sample of 50 premature infants divided into study or control groups and they were matched with gestational age and birth weight. Tool: Brazelton Neonatal Behavioral Assessment Scale is used to assess neurobehavioral development of infants from birth to two months of age. Method: Premature infants divided into two groups; (a) study group who receiving tactile stimulation (b) control group who receiving routine hospital care only. Neurobehavioral development using Brazelton’s Neonatal Behavior Assessment Scale (NBAS) was assessed at initial contact and after 5 days of intervention and on discharge. Results: showed that the premature infants of the study had better neurobehavioral development than those in the control group with statistical significant differences were found between the study and the control groups Conclusion: It was concluded from the findings of the current study that premature infants who received tactile stimulation had better neurobehavioral development than those who didn’t receive it and had only the hospital routine care. Keywords: Tactile stimulation, neurobehavioral development, premature infant