A general mathematical model for a fixed bed immobilized enzyme reactor was developed to simulate the process of diffusion and reaction inside the biocatalyst particle. The modeling and simulation of starch hydrolysis using immobilized α-amylase were used as a model for this study. Corn starch hydrolysis was carried out at a constant pH of 5.5 and temperature of . The substrate flow rate was ranging from 0.2 to 5.0 mL/min, substrate initial concentrations 1 to 100 g/L. α-amylase was immobilized on to calcium alginate hydrogel beads of 2 mm average diameter. In this work Michaelis-Menten kinetics have been considered. The effect of substrate flow rate (i.e., residence time

Undoubtedly, rutting in asphalt concrete pavement is considered a major dilemma in terms of pavement performance and safety faced by road users as well as the road authorities. Rutting is a bowl-shaped depression in the wheel paths that develop gradually with the increasing number of load applications. Heavy axle loadings besides the high pavement summer temperature enhance the problem of rutting. According to the AASHTO design equation for flexible pavements, a 1.1 in rut depth will reduce the present serviceability index of relatively new pavement, having no other distress, from 4.2 to 2.5. With this amount of drop in serviceability, the entire life of the pavement in effect has been lost. Therefore, it is crucial to look at the mechani

This article discusses the most beloved and creative dialect of the Arabs - the Iraqi dialect, despite its complexity, but it has a lot of beautiful foreign vocabulary. We followed a descriptive and historical approach, also tracked phonetic changes in this dialect, and then gave phonological explanations for these phenomena, trying to connect most of the phenomena with their historical roots in the standard Arabic "al-Fussha" and in ancient Arabic dialects. Most modern linguists have realized the need to study these dialects, since many of the modern dialect characteristics are only extensions of some ancient Arabic dialects, and do not refer them to the classical language. The study of modern Arabic dialects may be faced with a nu

Gas Lasers are important tools that are used in variety purposes, for their low and (cw) output power. The aim of this study was to prepare a way to calculate an optimum stimulated emission cross-section in a gas laser containing a mixture of Xenon and Neon by (30%-70%). The process was a theoretical study of each gas in separate in terms of their physical properties as an active medium. The results of these calculations are logic and more convenient than other mixtures used before

The study begins with the idea that advertising is a form of culture. Therefore, it is not possible to be surrounded by an actual briefing from one-sided premises such as those that are based solely on the artistic, aesthetic or technical aspects, without linking it to the culture in which it is produced. The researcher attempts to shed light on the relation between the advertising letter and the concept of gender. And here lies the importance of the research as the content of the ads and their form and implicit values in the text and image reflect the cultural values that must be identified as well as the most important roles that are stereotyped in advertisements and their relationship to the culture of society. Advertising is an importan

Mechanism of Arbitration in the Stock Exchange Disputes

.

   Fracture pressure gradient prediction is complementary in well design and it is must be considered in selecting the safe mud weight, cement design, and determine the optimal casing seat to minimize the common drilling problems. The exact fracture pressure gradient value obtained from tests on the well while drilling such as leak-off test, formation integrity test, cement squeeze ... etc.; however, to minimize the total cost of drilling, there are several methods could be used to calculate fracture pressure gradient classified into two groups: the first one depend on Poisson’s ratio of the rocks and the second is fully empirical methods. In this research, the methods selected are Huubert and willis, Cesaroni I, Cesaroni II,