This work describes the weathering effects (UV-Irradiation, and Rain) on the thermal conductivity of PS, PMMA, PS/PMMA blend for packaging application. The samples were prepared by cast method at different ratios (10, 30, 50, 70, and 90 %wt). It was seen that the thermal conductivity of PMMA (0.145 W/m.K), and for PS(0.095 W/m.K), which increases by PS ratio increase up to 50% PS/PMMA blend then decreased that was attributed to increase in miscibility of the blend involved. By UV-weathering, it was seen that thermal conductivity for PMMA increased with UV-weathering up to (30hr) then decreased, that was attributed to rigidity and defect formation, respectively. For 30%PS/PMMA, there results showed unsystematic decrease in thermal conductivity, which was attributed to unsystematic degradation. By Rain-weathering, thermal conductivity PS, PMMA, and 30 %PS, PMMA, it was seen systematic decreased in PS and 30 % PS/PMMA thermal conductivity; and systematic decrease in PMMA thermal conductivity. That due to the water diffusion in the samples that created some voids, bubbles, and results in decrease in thermal conductivity. This result was attributed to the decrease in adhesive between the components of polymer systems. The results suggested that the samples involved could be used for packaging application.
The interlaminar fracture toughness of polymer blends reinforced by glass fiber has
been investigated. Epoxy (EP), unsaturated polyester(UPE), polystyrene (PS),
polyurethane (PU) and their blends with different ratios (10%PS/90%EP),
(20%PS/80%EP), (20%PU/80%EP) and (20%PU/80%UPE) were chosen as a matrices A
sheet of composites were prepared using hand lay -up method, these sheet were cut as the
double cantilever beam (DCB) specimen to determine interlaminar fracture toughness of
these composites .Its found that, blending of EP,UPE with 20% of PU will improve the
interlaminar fracture toughness ,but the adding of 10% PS, 20%PS to EP will decrease
the interlaminar toughness of these composites.
The products of composites material are very sesetive to many variables, such as manufacturing process, additive materials, …. etc. Filler or additive plays a major role to determine the formation of the properties and behavior of the composites. In this study, polyethylene terephthalate-based compounds were produced and characterized. The work is concerned to prepare samples of Polyethylene terephthalate (PET) - zinc-ferrite (ZnFe2O4) with different addition ratio as zinc-ferrite (1, 2, 5, 10, 15 and 20) wt% obtained from mixing the solution with a hot pressing method applied under optimum conditions. The densities of the composites for all samples were calculated. Through the work the diffusion of zinc-ferrite i
... Show More The Dopping effect by methyl orange ( )on optical constants [Refractive index (n), extinction coefficient(K0),real and imaginary parts of dielectric constant(εr &εi)] of poly methyl methacrylat (PMMA) that additive to this polymer with both percentages 2% and 4% at thickness(145)µm have been studied. This study has been done by recording the absorption and transmission spectra in the wavelength range (200-900)nm . The results showed that all optical parameters are increased by increasing dopping rate except the transmission was decreased.
In this research we study a variance component model, Which is the one of the most important models widely used in the analysis of the data, this model is one type of a multilevel models, and it is considered as linear models , there are three types of linear variance component models ,Fixed effect of linear variance component model, Random effect of linear variance component model and Mixed effect of linear variance component model . In this paper we will examine the model of mixed effect of linear variance component model with one –way random effect ,and the mixed model is a mixture of fixed effect and random effect in the same model, where it contains the parameter (μ) and treatment effect (τi ) which has
... Show More- The problem of infertility considers one of the chronic problem a which faced the
individual & families equally . This problem causes a negative effects in psychological ,
social and development fields. The infertility contributes in weakening the human
development, when the human development has become as a centre point which centered
about individual preparing , rehabilitation, training and knowledge toreach to the required
excellence.
We think that , the infertility destroys the socially development; therefore the socially and
scientific institutions are working hard to find successful solution to resolve the problem
infertility through sophisticated and scientific methods. This problem
Grass trimming operation is widely done in Malaysia for the purpose of maintaining highways. Large number of operators engaged in this work encounters high level of noise generated by back pack type grass trimmer used for this purpose. High level of noise exposure gives different kinds of ill effect on human operators. Exact nature of deteriorated work performance is not known. For predicting the work efficiency deterioration, fuzzy tool has been used in present research. It has been established that a fuzzy computing system will help in identification and analysis of fuzzy models fuzzy system offers a convenient way of representing the relationships between the inputs and outputs of a system in the form of IF-THEN rules. The paper presents
... Show MoreThe study of Stress- Strain relation for novolac reinforced by qujurate plant was carried out before and after the immersing in boiled water at 100C0 . It was found that the compression strength and surface hardness decreased when the composites immersed in boiled water for long times.
In this work, a convex lens concentrating solar collector is designed and manufactured locally by using 10 convex lenses (concentrator) of a diameter 10cm and one Copper absorber tube of a diameter 12.5mm and 1mm in thickness 1m length. Two axes manual Tracking system also constructed to track the sun continuously in two directions. The experiments are made on 17th of May 2015 in climatic conditions of Baghdad. The experimental data are fed to a computer program to solve the thermal performing equation, to find efficiency and actual useful energy. Then this data is used in numerical CFD software for three different absorber diameters (12.5 mm, 18.75 mm and 25 mm). From the results that obtained the maximum the
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