In this study, polyester composites reinforced with pistachio shells powder (P.) with an average
diameter (150 – 200 μm) with different weight ratios (0.5%, 1%, 1.5%, 2%, and 2.5%) were
prepared to the resin. The Shore D hardness, thermal conductivity (K), and the glass transition
temperature (Tg) of the samples were examined. The results showed that the Shore D hardness
increases with the increase of the reinforcement ratio and its maximum value is (87.55) at (2.5%
P.) While the value of hardness at (0%) is (86.5). The thermal conductivity increases slightly with
the increase in the percentage of reinforcement and its maximum value is (0.213253 W/ m. K) at
(2.5% P.), while the value of K at (0% P.) is (0.170264W/ m. K), but with this slight increase in
thermal conductivity, polyester composites remain from the insulating materials. The minimum
(Tg) of (UPE/ P.) composites was the value (113.898°C) at (2.5% P.). Polyester composites are
used in wood paints, either in primitive finishes or final finishes.
In this research the effect of cooling rate and mold type on mechanical properties of the eutectic
and hypoeutectic (Al-Si) alloys has been studied. The alloys used in this research work were (Al- 12.6%Si
alloy) and (Al- 7%Si alloy).The two alloys have been melted and poured in two types of molds with
different cooling rates. One of them was a sand mold and the other was metal mold. Mechanical tests
(hardness, tensile test and impact test) were carried out on the specimens. Also the metallographic
examination was performed.
It has been found that the values of hardness for the alloys(Al-12.6%Si and Al-7%Si) which poured in
metal mold is greater than the values of hardness for the same alloy when it poured in a heated
Background: The aim of this study was to evaluate the effect of three types of light curing devices QTH, LED and Flashmax on the surface microhardness of three types of bulkfill composite resins; Filtek Bulkfill posterior composite ( 3M), Tetric Evo Ceram ( Ivoclar Vivadent) and Sonicfill composite ( Kerr) Materials and methods: Total number of 90 samples was prepared, 30 samples for each type of bulkfill composite, were divided into three main groups, group A: Filtek posterior bulkfil (3M), group B: Tetric Evo Ceram (Ivoclar Vivadent) and group C: contain Sonicfill composite (kerr). Which then divided into three subgroups (n= 10) (1) Samples cured by QTH system (2) Samples cured by LED system and (3) samples cured by Flashmax system the
... Show MoreThe conductance of solu ti ons of cysteine in water at different concentrations and temperatures has been measured. These solutions obey Onsagcr equation and give linear relations especially at low concentrations. In more concentrated solutions a deviation from the equation is observed.
The molar conductivity of these solutions decreases with t he increase in concen trations at constant temperature.
The values of the ionization constants and the conductivity at infin ite
dilution for each temperature have been calcu lated.
In this study, the number of times of heating of olive oil was studied. For the different refineries, the study was conducted using a temperature of 300K and for several times to determine the validity of the olive oil which is used for frying purposes after it was used for more than once times. It was found that there were significant changes in the behavior of the photophysical behavior like absorption and emission; there are changes in the nature and composition of the olive oil molecule, which makes it not useful for human use. The number of heating times was ten. The heating times also showed significant changes in the nature of the oil, such as color, taste, density, and smell.
The experimental study showed the use of closed cavity wall (the thickness of the cavity 5cm) made a percentage reduction in the cooling load caused by heat gain from the wall by (21.5 %) compared with the conventional wall. also the thermal resistance of the closed cavity was an average (0.2 m2.oC/W).
The experimental results of the study showed that the use of closed cavity wall reduced the average temperature of the inner surface of the wall during the day, and that the reduction was an average (0.45 oC) when compared with the conventional wall , as well as the use of closed cavity wall reduced the temperature difference range of the inner surface of the wall during the day, and that the
... Show MoreLeishmaniasis is an endemic disease in Iraq, where both forms of the disease, cutaneous and visceral, are found. The effect of Zinc oxide nanoparticles (ZnO NPs) with mean particle size less than 100 nanometer (nm) on viability and growth rate of Leishmania donovani promastigotes was evaluated. The anti-leishmanial activity of different concentrations (0.1, 0.2, 0.4, 0.6, 0.8, and 1 μg/ml) of ZnO NPs was investigated on promastigotes growth rates and viability in comparison to promastigotes exposed to the same concentrations of sodium stibogluconate (Sb) (pentostam).The inhibitory concentrations (IC50s) of ZnO NPs were calculated after 24 , 48 and 72 hr which were (0.871, 0.156 and 0.120 μg/ml) respectively with significant (p< 0.05
... Show MoreIn this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hal
... Show MoreThis study was carried out to estimate the effect of shaliness on water saturation from TN field of Niger Delta. The conventional Archie and the Shaly-sand water saturation models was used in the evaluation of wells. Two sand bodies (Sand 01 and 02) were mapped with thicknesses range from 76.8ft to 119.3ft across the three wells for Sand 01 and 187.5 to 339.9ft across wells TN_1 and TN_4 for Sand 02. The cross plot of the effective porosity (φe) versus volume of shale (Vsh) show a decrease in the effective porosity with an increase in shale volume. This reveals a laminated shale pattern across the reservoir sands. The estimations from the conventional method and the Shaly-sand models of Simandoux and Indonesia show a clear disparity due
... Show MoreTo investigate the effect of chemical mutagens: sodium azide (SA), hydrazine hydrate (HZ) and maleic hydrazine (MH) on morphological variations of faba bean traits. Seeds were soaked in distilled water for six hours, then in different concentrations of the above mentioned mutagens (0.01, 0.03, 0.05%) represented by (C1,C2 and C3 respectively) for six hours and planted in the field in winter 2013-2014. Factorial Experiment was arranged in Randomized Complete Block Design (RCBD) with three replications to each treatment. The results of statistical analysis showed significant differences among studied treatments. All mutagens showed significant reduction in plan height and number of branches per plant compared with control plants which gave
... Show MoreThe toxicity of insecticide dichlorvos (90%) was tested in ovaries of mosquito fish using three sublethal concentrations (0.3, 0.6, 0.8 µg/L) and studied their effects on the means of body and ovary weights, gonadosomatic index, ovum size and ova number. Results showed that there was a significant (P<0.05) decrease in body and ovary weights, ovum size and ova count. However, there was no significant (P<0.05) difference in gonadosomatic index in treated groups with the three concentrations of dichlorvos compared with the control group. This study was added evidence on the ovular toxicity of dichlorvos concerning its effect on fish production as well as reduction in the means of productive offspring and their survival.