Applied Science Private University

About: Applied Science Private University is a education organization based out in Amman, Jordan. It is known for research contribution in the topics: Population & Catalysis. The organization has 4124 authors who have published 5299 publications receiving 116167 citations.

Effect of homogenization treatment and silicon content on the microstructure and hot workability of dilute Al–Fe–Si alloys

Abstract: The effect of the homogenization treatment on the microstructure and hot workability of two dilute Al–Fe–Si alloys was investigated using optical microscopy, SEM, EBSD, electrical conductivity measurements and hot compression testing. Homogenization promoted the phase transformation from the metastable AlmFe or α-AlFeSi phase to the Al3Fe equilibrium phase and induced a significant change in solute levels in the solid solution. The AlmFe dissolved and transformed completely at 550 °C in both alloys. The α-AlFeSi was transformed at 590 °C in the low Si alloy (Al–0.3Fe–0.1Si), whereas it began to decompose and transform to Al3Fe at 630 °C in the high Si alloy (Al–0.3Fe–0.25Si). The flow stress behavior of dilute Al-Fe-Si alloys was primarily controlled by the amount of Fe and Si in the solid solution. Homogenization at 550 °C significantly reduced the solid solution levels due to the elimination of the supersaturation originating from the cast ingot and produced the lowest flow stress under all of the deformation conditions studied. An increase in the homogenization temperature from 550 to 630 °C increased the flow stress by 10–23% and 15–45% for the low Si alloy and the high Si alloy, respectively, over the range of deformation conditions examined. An increase in the silicon level from 0.10% to 0.25% raised the overall flow stresses by 4–11% due to increased solute levels for given homogenization conditions.

The use of docking-based comparative intermolecular contacts analysis to identify optimal docking conditions within glucokinase and to discover of new GK activators

Abstract: Glucokinase (GK) is involved in normal glu- cose homeostasis and therefore it is a valid target for drug design and discovery efforts. GK activators (GKAs) have excellent potential as treatments of hyperglycemia and diabetes. The combined recent interest in GKAs, together with docking limitations and shortages of docking valida- tion methods prompted us to use our new 3D-QSAR ana- lysis, namely, docking-based comparative intermolecular contacts analysis (dbCICA), to validate docking configu- rations performed on a group of GKAs within GK binding site. dbCICA assesses the consistency of docking by assessing the correlation between ligands' affinities and their contacts with binding site spots. Optimal dbCICA models were validated by receiver operating characteristic curve analysis and comparative molecular field analysis. dbCICA models were also converted into valid pharma- cophores that were used as search queries to mine 3D structural databases for new GKAs. The search yielded several potent bioactivators that experimentally increased GK bioactivity up to 7.5-folds at 10 lM.

Inexact Piecewise Quadratic Programming for Waste Flow Allocation under Uncertainty and Nonlinearity

Abstract: In practical waste management systems, most relationships among different system components are nonlinear in nature. Effects of economies-of-scale can often bring about such nonlinearity in objective functions within an inexact optimization framework. To handle both nonlinearity and uncertainty, an inex act piecewise quadratic programming (IPQP) model was developed through coupling piecewise linear regression with interval linear programming. In IPQP, uncertainties expressed as intervals for transportation/operation costs, treatment capacities, waste generation rates, waste flows/amounts were reflected; a more accurate approximation for nonlinearities reflecting effects of economies-o f-scale between unit transportation costs and waste flows as well as between unit operation costs and waste treatment amounts were provided. An interactive algorithm was designed for solving IPQP. IPQP was applied to a hypothesis case of waste allocation planning and compared with a conventional inexact quadratic programming model (IQP). The results indicated that, in the investigated waste allocation system, the optimized waste flows from the districts to the waste treatment facilities (WTFs) and the optimized waste treatment amounts in WTFs had no significant differences between both models. However, most of unit transportation costs or unit operation costs in IPQP were less than those in IQP, which finally contributed to a lower net system costs in IPQP than IQP. Th is implied that the often ignored effects of economies-of-scale should be considered accurately in the real-world waste management system to obtain lower costs. Strategies to balance the tradeoff between approximation accuracy and computational complexity for IPQP were also discussed.

On Detecting Total or Partial Symmetry of Switching Functions

Abstract: This note presents a method for identifying total or partial symmetry of switching functions based on the application of the principle of residue test by numerical methods. The invariance of a switching function under a single interchange of two variables can be readily detected from the equality of some of the residues of expansion about these two variables. This procedure of detecting invariance is directly applied for the identification of total or partial symmetry of a switching function whose variables of symmetry may be either all unprimed (or all primed), mixed, or of multiform nature.