In this research, the mechanical properties of natural rubber blends in different proportions (70:30, 85:15, 100: 0 55:45 and phr) was studied through the use of two types of fillers (carbon black and titanium dioxide Nano) which show through tests conducted on the prepared models that increase fillers content which leads to improve the tensile properties (tensile strength, elastic modulus, elongation, hardness and compressibility). As shown by the results that the presence of polypropylene (PP) in the mix combination works to reduce the degree of intumescent and increase its content in the composition of mixtures which leads to get a great resistance to chemicals (acids, bases and oils).
This study included preparation for the unsaturated polyester samples before and after reinforced by the Alumina oxide powder of different volume fraction amounting (2%,4%,6%). And this research included the study of some of mechanical properties such as (Hardness,compressive,wear). The results showed that the increase of the hardness and compressive strength after the reinforced and the increase with the volume fraction increase. As the wear test shows that the wear rate increases with applied load increase(5,10,15) from (10.6-18.6) gm/cm befor reninforced and from(5.4-15.2)gm/cm,(4.7-12.9)gm/cm,(48.1)gm/cm,after reinforced from the different volume fraction, and t
... Show MoreBackground: Dental erosion is a common oral condition which results due to consumption of high caloric and low pH acidic food such as carbonated drinks and fruit juices. It is expected that these food types can cause irreversible damage to dental hard tissues and early deterioration of the dental restorations. So, this study aimed to evaluate and compare the erosive potential effects of orange fruit juice and Miranda orange drink on the microhardness of an orthodontic composite material. Materials and methods: Thirty discs with a thickness of 2 mm and a diameter of 10 mm were prepared from orthodontic bonding composite. The prepared discs were equally divided into three groups (n=10). Microhardness analysis was carried out both prior to
... Show MoreAbstract
In this research, the morphology and mechanical properties of (Epoxy/PVC) blend were investigated. (EP/PVC) blend was prepared by manual mixing of epoxy resin with different weight ratios of (Poly vinyl chloride (PVC) after dissolving it in cyclohexanon). Five sheets of polymer blends in wt% included (0%, 5%, 10%, 15% and 20%) of PVC were prepared at room temperature. Tests were carried out to study some mechanical properties for these blends and compared with the properties of pure epoxy. The morphology of the prepared materials was examined to study the compatibility nature between the two polymers under work. It was found that the best ratio of addition is (20%) of PVC.
... Show MoreIncreased diseases and obesity currently due to increased production and excessive consumption of foods manufactured from non-food sweeteners without attention to the risk of consuming those additional high calories due to consuming these refreshing products such as juices and other various drinks, especially in the summer season by most segments of Iraqi society, especially workers, children and school students the aim of this study. Therefore, the study designed to replace sucrose with 0.03, 0.04 and 0.05% of each of the white stevia crystals and milled dry stevia leaves in the laboratory manufacture of juices and its effect on the general and sensory characteristics and the extent of their acceptability among the specialized r
... Show MoreIn 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
Interest has largely centered on the use of plant fibers to reinforce plastics, because these fibers are abundant and cheap. Carrot fibers (Curran) have been extracted from carrot, left over from carrot juice manufacture. The fibers of two sizes fine (50<µm) and coarse (100-150 µm) have been mixed with epoxy in four levels of loading (10, 20, 30, 40 wt %) respectively. Impact test, shore d hardness test and three point bending test of epoxy and carrot fiber-epoxy composites samples have been determined. The impact strength values of samples prepared with fine and coarse fibers increased as compared with pure epoxy sample. Hardness values increased, and the Young’s modulus values decreased with fiber content of both sizes.
In this study, polymeric composites were prepared from unsaturated polyester as a base material with glass powder (fluorescent) in different weight ratios (4, 6, 8, 10,and 11%) as a support material and after comparison before and after reinforcement of the prepared composites, an increase was found. In the values of mechanical properties (hardness, compressive strength), the shock resistance values decreased, but an increase in temperature leads to an increase in the values of shock resistance, as well as the values of compressive strength And it reduces the hardness value.
ABSTRACTObjective: The objective of this study is to develop a controlled release matrix tablet of candesartan cilexetil to reduce the frequency of administration,enhance bioavailability and improve patient compliance; a once daily sustained release formulation of candesartan cilexetil is desirable.Methods: The prepared tablets from F1 to F24 were evaluated with different evaluation parameters like weight variation, drug content, friability,hardness, thickness and swelling ability. In vitro release for all formulas were studied depends on the type and amount of each polymer, i.e. (16 mg,32 mg and 48 mg) respectively beside to the combination effect of polymers on the release of the drug from the tablet.Results: In vitro release show
... Show MoreIn this paper, we used two monomers, 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) and m,m'-diaminobenzophenone (m, m’-DABP), to produce polyamide acid and then converted it to polyimide (PI). The effects of phosphoric acid (H3PO4) molarity (1, 2, and 3 M) on the structural, thermal, mechanical, and electrical characteristics of the polyimides/polyaniline (PI/PANI) nanocomposites were studied. Two sharp reflection peaks were developed by the addition of PANI to PI. When 3 M H3PO4 is added, the crystalline sharp peak loses some of its intensity. The complex formation of PI/PANI-H3PO4 was confi
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