Microstructural characterization of rapidly solidified Al-Li-Co powders

A study of the combined effect of alloying elements and melt superheat has been carried out on the as-solidified structure of rapidly solidified Al-Li-Co powders. Three alloys,viz., Al-3 pct Li, Al-3 pct Li-0.4 pct Co, and Al-3 pct Li-0.8 pct Co were chosen, and the liquid melt in each alloy atomized from the temperatures 1173 and 1073 K, using the centrifugal atomization technique. The microstructural characterization was done using light, scanning, and transmission electron microscopy. Four types of microstructures,viz., dendritic, cellular, equiaxed-type, and featureless structures, were observed by light microscopy. The cooling rate, as determined from the same, lay in the range 10⁴ to 10⁶ Ks⁻¹, but was seen to go beyond 10⁷ Ks⁻¹ when estimated from TEM micrographs. On the micro-level, the Al-Li powders were found to exhibit dendritic structures with differing morphologies, whereas low-angle cell walls with perturbed interfaces were the main structural features observed in the Al-Li-Co alloys. Increasing both cobalt content and powder particle diameter favored transition from dendritic into cellular structure. The featureless zone was comprised mainly of elongated columnar grains (0.2 μm width and 1.5 μm length). A mechanism describing the cellular structure formation has been proposed. Aging of the melt-quenched powders at 473 K for times up to 100 hours results in the dissolution of the cellular structure. A mechanism for the same has been postulated. The difference in the superheats chosen in the present work is found not sufficient to cause drastic microstructural changes. Central Metallurgical Research and Development Institute, National Research Centre, Dokki, Cairo, Egypt     

A simulation optimisation tool for planning of low-income housing projects

Construction of low-income housing projects is a recurring process and is associated with uncertainties that arise from the unavailability of resources. This paper presents a case study that discusses how computer simulation and optimisation are used to aid government agencies and/or contractors in planning of such projects. It illustrates the optimisation of project objectives, taking into consideration the interaction amongst involved resources. As such, total duration and the associated total costs, including direct and indirect costs, can be estimated and optimised. One Youth Habitation project that is executed in 6th of October City in Egypt is analysed in a step-by-step procedure to demonstrate the capability of proposed computer simulation and optimisation prototype (named LIHouse{_}Sim) in the modelling construction of low-income housing projects using bearing block walls with hollow core technique. The presented tool proves its practicality to contractors in estimating the time and costs of the recurring process of low-income housing construction, considering complex interdependencies between construction resources and the uncertainties associated with construction activities. The LIHouse{_}Sim prototype is used to perform a wide analysis for the alternative of the effective optimisation criteria in the bearing block walls/hollow core technique and for the genetic algorithm optimisation approach elements.     

Bioactive phytochemicals, nutritional value, and functional properties of cape gooseberry (Physalis peruviana): An overview

Exotic fruits play an important role in nutrition as an excellent base for low calorie and dietetic products. Highly valued for its unique flavor, texture and color, recent research has shown cape gooseberry (Physalis peruviana) to be high in many beneficial compounds. The diversity of functional applications to which P. peruviana can be put gives this fruit great importance. The food industry has used cape gooseberry in different products including beverages, yogurts and jams. With the rapidly growing popularity of this unique fruit it is important to have a comprehensive reference for its nutritional benefits. This review provides a valuable source for current knowledge on bioactive phytochemicals and further development of P. peruviana for functional foods as well as nutraceutical and pharmaceutical industries.     

Preparation and structural characterization of Zn1?xMnxSe thin films

Undoped and Mn doped ZnSe nanoparticles thin films of thickness ranging from 20 to 120 nm have been successfully synthesized via inert gas condensation (IGC) technique with constant Argon gas flow rate and deposition temperature 300 K. The energy dispersive X-ray analysis (EDX) for freshly deposited Zn_1−xMn_xSe thin films were carried out and revealed that Mn contents (x) were 0, 0.05, 0.16 and 0.25. The as-prepared deposited thin films of different thickness were examined using transmission electron microscope (TEM) and showed that all films were nanocrystalline with particle size ranging from 4.1 to 6.6 nm. The grazing incident in-plane X-ray diffraction (GIIXD) patterns verified nanocrystalline single phase zinc blende structure for 80 nm film thickness for all examined Zn_1−xMn_xSe compound films. A broadening of main characteristic lines (111), (220) and (311) of cubic phase was observed and was attributed to the lower particle size in nanocrystalline examined Zn_1−xMn_xSe compound films.     

Clinical correlation of neuropsychological tests with 1H magnetic resonance spectroscopy in hepatic encephalopathy

The mortality from coronary and cerebrovascular diseases is higher in Finnmark County than in other Norwegian counties. In a population-based cohort study, we compared the incidence of myocardial infarction, stroke, and diabetes mellitus in different ethnic groups in Finnmark. A total of 10,622 subjects of Norse, Sami, and Finnish origin were followed for 14 years. During approximately 150,000 person-years, we identified 509 and 84 cases of myocardial infarction, 107 and 75 cases of stroke, and 96 and 73 cases of clinical diabetes mellitus among men and women, respectively. A total of 533 men and 199 women died. Norse subjects born outside of Finnmark had the most favorable risk factor levels and, in general, the lowest incidence of disease. Men of Finnish origin had a higher incidence rate of all endpoints than other men, and Finnish women had a higher incidence rate of myocardial infarction than other women. Sami women were more obese but did not have a higher diabetes mellitus incidence than other women. After adjustment for major cardiovascular risk factors and height, most ethnic differences were attenuated.     

Artificial neural networks: a novel tool for detecting GMO

Introduction of artificial neural network (ANN) into the field of GMO detection is the aim of this investigation. The usefulness of ANN to predict transgenic maize (Bt-176) based on chemical composition of the extracted crude oil was evaluated. The training set, comprised of a composition of major and minor lipid components as inputs and outputs. Crude oil extracted from the genetically modified maize (Bt-176) and non-transgenic maize was characterized in terms of its fatty acids, phytosterols and tocopherols distribution as well as of its lipid classes and unsaponifiables amounts. The results obtained from lipid distribution analysis showed that the grains of Bt-176 maize were comparable in their composition to that of the control maize. The analytical data have been elaborated by supervised pattern recognition technique ANN in order to classify genetically modified maize (Bt-176) and conventional maize as well as to authenticate the origin of the samples.