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(Hall, Barry, Dawber, and McNamara, 1967) Prevalence of gouty arthritis was found to increase with rising serum uric acid levels. In order to explain these observations, it is necessary to understand the difference between solubility and nucleation. The solubility of a crystalline solid is defined as its concentration in a solution in equilibrium with crystals of the substance. This equilibrium concentration can be obtained only by long contact of the solution with the crystals. Solubility depends on a variety of factors including temperature, pressure, the other species present in the solution, and the perfection and size of the crystals.Nucleation, on the other hand, is the birth of a new crystal. Ifa solvent is slowly removed by evaporation from a solution originally containing no crystals, eventually the solute concentration will equal, and then slightly exceed, the solubility. Nevertheless, crystals will not form even though the concentration exceeds solubility. Such a supersaturated solution is metastable in that although crystals are not generated spontaneously, a crystal will grow if introduced into such a solution. This behaviour may be traced to the enormous surface energy associated with the small cluster of molecules required for a crystal of observable size to form (see Nielsen, 1964; StricklandConstable, 1968). As evaporation continues, the concentration eventually reaches the point required for spontaneous generation (nucleation) of a small crystal, which then grows. Homogeneous nucleation occurs if the crystal forms in the absence of foreign surfaces; heterogeneous nucleation occurs if it forms on a foreign surface. Often additional crystals are formed in the presence of an existing crystal. This is called crystal breeding or secondary nucleation (Strickland-Constable, 1968). Heterogeneous nucleation and secondary nucleation often occur at much lower supersaturations* than required for homogeneous nucleation. The ability of a surface or particle to cause heterogeneous nucleation increases as the supersaturation increases, perhaps explaining why the frequency of gout increases rapidly with the increase in hyperuricaemia (urate supersaturation).We may then regard the first gout attack in a hyperuricaemic individual as a nucleation event. But why does nucleation occur in some hyperuricaemic individuals and not in others? Although there is no ready answer the influence of various factors on nucleation can be investigated in the laboratory. In the only previous experiments known, several organic dyes were seen to inhibit the onset of precipitation (Gupta, 1970). However, uncertainty exists as to whether the results indicated merely a very low growth rate or actual inhibition of nucleation. The experiments reported here represent the first careful investigation of nucleation of monosodium urate. * Supersaturation is the amount by which the concentration exceeds the solubility.

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The research aims to determine the best combination of the controlling factors that govern geopolymer concrete’s mechanical and physical properties by utilizing industrial waste. Therefore, a review on the controlling factors was conducted. Firstly, it is to identify the controlling factors, namely chemical composition, alkali activation solution, water content, and curing condition. Secondly, understanding the relationship between these controlling factors and the properties of geopolymer concrete. These factors are analysed to the mix proportion components. Finally, a new proportion method is proposed based on combining ACI 211 standard and recommended molar ratios of oxides involved in geopolymer synthesis. The effect of aggregate has been taken into account by applying the absolute volume method in mix design. Based on the results of the study, it is expected to determine the optimal mix proportions based on multi-responses.

The aim of this study is to extract the important antioxidants components of flaxseed in different ways. The Determination of total phenol content, antioxidant activity and percentage of linoleic acid inhibition by DPPH for the components (Lignan, oil, 80 and 100% ethanolic extract and the deionized water extract). The components of flaxseed oil were identified using GC/MS. The efficiency of the mixture (80% ethanolic extract and oil)  was determined by inhibiting the process of oxidation of linoleic acid during storage periods (0, 7, 14 and 21 days) at laboratory temperature, and the following results were obtained:  The yield of lignan, oil, ethanol extract (80 and 100)% and deionized  water were (0.12,40.52,10.9,9.6 and 13 )g.100g-1 seed respectively, while the total phenolic content of the above components was (700,1165,3315,2098 and 483)mgGAE.100g-1,respectively. Flaxseed oil gave the highest antioxidant activity 79.3% with an inhibition percentage 73.19%, compared with ethanolic extract, lignan and water extract. The diagnosis of GC/MS flaxseed oil showed that  the oil was contained in compounds with antioxidant activity, including mono, di and tri-terpens such as Copaene, Monoterpene, ?- Sesquiphellandrene, Squalene, diethyl phthalate ,?-Sitosterol and Hexadecanoic acid, as well as, the presence of ascorbic acid and gamma tocopherol with good concentrations (8.68 and 2.62)% respectively. The mixture of 80% ethanol and oil extract showed an effect in decreasing of peroxide values with an increase of concentration of the added mixture (0.1, 0.4 and 0.10 mg.mg-1). The maximum reduction of the peroxide value at the concentration was 0.6 mg. mg-1, compared with the standard sample during the different durations of storage.