Polyvinyl alcohol, (PVA) was prepared using polyvinyl acetate emulsion (manufactured by Al-Jihad factory,
That-Al-Sawary Company) as a local raw material. In this investigation, polyvinyl acetate emulsion was converted to
solid form by coagulation the polymer from its emulsion using sodium sulphate salt as coagulant aid, then alcoholyzed
the solid polyvinyl acetate in methanol using sodium hydroxide as catalyst, polyvinyl alcohol produced by this method is
a dry, white to yellow powder.
Three affecting variables on the degree of hydrolysis of PVA were studied, these variable are Catalyst to
polymer weight ratio in the range of 0.01 – 0.06, reaction time in the range of 20 – 90 min, and reaction temperature in
the range of 25 – 50 oC. The effect of degree of hydrolysis of PVA produced on its properties such as water solubility
and degree of polymerization were studied also.
Finally the alcoholysis reaction kinetics were studied to determine the reaction constants such as initial rate
constant and degree of autocatalytic effect of the alcoholysis reaction. It was found that the degree of hydrolysis of
formed polyvinyl alcohol increase with increasing of variables catalyst concentration, reaction time and reaction
temperature, furthermore, the water solubility of PVA increase with increasing degree of hydrolysis up to about 87 %
after this value the solubility is decrease, also the degree of polymerization of PVA decrease with increasing of degree of
hydrolysis up to about 89 %.
This present work adopts the analytic and descriptive methodology to recognize and analyze the major challenges faced by the Iraqi government. The study focuses on the press and national partiers’ cabipility of changing and unifying the opinions of the public in a way that serves the Iraqi interest, taking into account the fact that the press is the fourth authority after the three major authorities, (Executive, Legislation and Judicial). The researcher has concluded that the Iraqi press and parties initiated a national front with the Iraqi people against the government’s signature of the treaty of (1930). The national front illustrated that signing the treaty strengthens the authority of the British occupation u
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The lesser grain boner Rhizopertha dominica is an important insect on grain in Iraq . in this study phenol and coumarin were isolated from Albizzia lebbek . the addition of there compounds to artificial diet at concentration of 3.4,5% couse high effects on the development of the studed insect larva.the larva were unable to complete its development to adult stage. More over, using 5% coumarin larva were died.Seed germination was not affected when seed were sprayed with concentration of 3,4,5% of coumarin and phenol.
The efficient removal of dissolved organic compounds (DOC) from wastewater has become a major environmental concern because of its high toxicity even at low concentrations. Therefore, a technique was needed to reduce these pollutants. Ion exchange technology (IE) was used with AmberliteTM IR120 Na, AmberliteTM IR96RF, and AmberliteTM IR402, firstly by using anion and mixed bed system, where the following variables are investigated for the process of adsorption: The height of the bed in column (8,10 and 14 cm), different concentrations of (DOC) content at constant flow rate. The use of an ion exchanger unit (continuous system) with three columns (cation, anion, and mixed bed) was studied.
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Education specialists have differed about determining the best ways to detect the
talented. Since the appearance of the mental and psychological measurement movement, some
scholars adopted intelligence ratios as a criterion to identify the talented and others went to
rely on the degree of academic achievement. Each of these two methods has its own flaws and
mistakes and a large number of talented children were victims of these two methods.
Therefore the need to use other scales for the purpose of detection of talented children
appeared because they provide valuable information which may not be obtained easily
through objective tests and these scales are derived from consecutive studies of gifted andtalented children
The purified frog skin peptides were tested on leukemic patients lymphocytes, which revealed effects of cytotoxicity. Four frogs (Rana ridibunda) were stimulated by single intra-peritoneal injection of norepinephrine-HCl . Five different peptides;1(18) A, 2(19) L, 3(20) I,4(21) E and 5(22) Y were isolated and quantified. The peptide 3(20)I had 5.87% of hemolysis, while healthy human lymphocytes cytotoxic activity was for 2(19)L with inhibition( -10.4%).All peptides were subjected to polyacrylamide gel electrophoresis. The results revealed peptides 1(18)A, 2(19)L, 3(20)I which appeared as low as 10 KDa marker. Theoretically, the whole polypeptide had a molecular weight 7488.61 Dalt
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The present study introduces description of a new species of genus Arboridia Zakhvaticin 1946, based on a large collection of Cicadellids. External morphological characters particularly male genitalia were discussed and illustrated. The genus Arboridia Zalchvatkiia (Typhlocybinae: Erythroneurini) contains small slender, fragil and attractively coloured and patterned leafhoppers. It was erected by Zakhvatkin in 1946 (Zalchvatkin, 1946). The overall length of adults ranges from 2.5 to 3.4 mm. Members of this genus can be recognized by inner apical cell of forewing which is long with oblique base; Cu confluent with this base at a point near the middle of the length of inner apical cell; two prominent circular deep brown spots on vertex (Zal
... Show MoreThe present study was conducted to determine the optimum conditions required for lipase enzyme activity extracted from germinated sunflower seeds, including temperature, pH, agitation, time of incubation, enzyme concentration, substrate type, and concentrations of mineral salts and EDTA. Optimum pH, temperature and time of incubation required for lipase stability were also determined. The results showede optimum lipase activity (3.251U/ml) wasund at 30 ÌŠC and pH 7 after 20 minutes of incubation when using 1 ml lipase enzyme with 0.02 ml of CaCl2 (10 mM) at 100 rpm of agitation and in the presence of olive oil as the substrate for enzyme reaction. EDTA appeared to have inhibitory effects, while Ca+2 and Mg+2 have stimulatory effec
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