Zero temperature phase diagram of the square-shoulder system

Particles that interact via a square-shoulder potential, consisting of an impenetrable hard core with an adjacent, repulsive, step-like corona, are able to self-organize in a surprisingly rich variety of rather unconventional ordered structures. Using optimization strategies that are based on ideas of genetic algorithms we encounter, as we systematically increase the pressure, the following archetypes of aggregates: low-symmetry cluster and columnar phases, followed by lamellar particle arrangements, until at high pressure values compact, high-symmetry lattices emerge. These structures are characterized in the NPT ensemble as configurations of minimum Gibbs free energy. Based on simple considerations, i.e., basically minimizing the number of overlapping coronae while maximizing at the same time the density, the sequence of emerging structures can easily be understood.Comment: Submitted to J. Chem. Phy

Effects of soil variation between peat soil and mineral soil on fruit quality of pineapple (Ananas Comosus) cultivars: N36 and josapine

Consumption of pineapple is predicted to increase in the near future in which the demand for continuous supply of the fruit becomes of major interest. This research is focused on finding the influence of growth medium between peat soil and mineral soil to the weight and production of vitamin C and sugar contents of the pineapple fruits. Two cultivars were investigated: N36 and Josapine. The vitamin C is quantified by Iodate Titration and sugar content is analyzed by Digital Refractometer. The chemical soil properties were analyzed by using atomic absorption spectrophotometer at the Soil Analysis Section laboratory from Department Of Agriculture, Malaysia. All data were analyzed statistically through ANOVA by using SPSS. Results indicated that pineapple planted on peat soil produced heavier fruits than those in mineral soil. N36 pineapple reports no significant difference (p < 0.05) of the vitamin C content and the sweetness between different cultivation soil types. However, Josapine pineapples cultivated on mineral soil (FIMA Plantation) produce significantly 115% higher vitamin C content (19.243 ± 7.191 mg∙100g-1), and significantly 30% lower sugar content (5.403 ± 1.721% °Bx) than cultivated on peat soil (Peninsula Plantations). The finding of the soil type’s influence on the fruit quality production is beneficial for pineapple producers and researchers to broaden up the development of pineapple-based products in the long run. The promotion of pineapple nutritional contents is beneficial to increase consumers’ knowledge and awareness on the importance of pineapple consumption especially in Asian regions

Focal Spot, Spring 1998

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