Applications of lumping kinetics methodology to complex reactive mixtures

The thesis concerns a comprehensive study to develop and assess the predictive capabilities of a lumping model for the kinetics of complex reaction mixtures containing a large number of reacting components. Two types of lumping models were developed to reduce the number of reaction kinetics, namely a discrete and a continuum lumping model. These models were applied on three different problems. In the first case study, a continuum model was developed for a mixture of n-paraffins (waxes) produced from the Fischer-Tropsch process; the paraffins range from C5 to C70 and undergoing catalytic hydrocracking. The model was run with two types of the reactant-type distribution functions to describe the yield of products from the isomerisation and cracking reactions. The model was used to study the effect of the operating conditions on the model parameters and the yield composition. Experimental data were used to optimise the model parameters. The optimal parameters were used to predict the product distribution of n-paraffins hydrocracking and their conversion. The new in this case study was used the carbon number as label in the continuum lumping model and to study how the effect of D(k) on the yield distribution. Good agreements have been obtained when running the model with D(k) employed a gamma function but it needs more time to solve the model than when employing a power law relation for D(k). In the second case study, both primary and secondary reaction kinetics of the pyrolysis of lignin were investigated by using the discrete lumping methodology. Two mathematical models were developed which consider the product as three lumps whilst the lignin was assumed to be an additional lump. The model’s results were validated against experimental data. In addition, a continuum lumping model was developed for the cracking of the tar to obtain lighter components. The novelty in this case study is to develop a kinetic model including primary and secondary reaction kinetics for the pyrolysis of lignin in a fluid bed pyrolyser and to study how the continuum lumping model for tar can be linked to the discrete lumping model. In the third case study, a model based on the continuum lumping approach was proposed to predict the molecular weight distribution of polymers during batch polymerisation. The result obtained from a continuum model was assessed, at this stage, only qualitatively; nevertheless, by analysing the weight distribution and the average of such distribution, conclusions were reached to assess the predictive capability of the lumping methodology. It is the first time that the continuum model with a yield distribution function is used to predict the molecular weight distribution of the polymerisation at various times

“Electronic Banking Problems and Opportunities: The Sudanese Context”

The term electronic banking means an electronic handling of all types of banking business, primarily over the internet. E-Banking is one of the most successful on-line businesses, which save the individuals and companies time and money. This paper investigates the problems and opportunities of the electronic banking in Sudan, whereas, the provision and use of financial services and products that conform to interest-free banking principles which pose many challenges. Banking sector plays a crucial role in economic growth, it allows an efficient transfer of resources from those who save to those who invest under certain rules and regulations, and this study highlights the fact that changes have always been the hallmark of this sector. Here, this study replicates, extends and adds a longitudinal dimension to a recently introduced information technology in banking and financial institutions. The study reviews the experience of the Sudan as a developing country, and it concludes that regardless of the progresses achieved in recent years namely, enacting of electronic transactions Act 2007, the study finds out many deficiencies, poor infrastructure, and lack of skilled and well-trained human resource force in banking sector and security, which remain the key factors that constrain the applicability of e-banking. Keywords: Electronic Banking, Problems, and Opportunities

Seasonal biodiversity and ecological studies on the epiphytic microalgae communities in polluted and unpolluted aquatic ecosystem at Assiut, Egypt

A qualitative and quantitative study on epiphytic microalgae was carried out seasonally from November 2015 to August 2016 to follow up their community structures on aquatic macrophytes related to some physico-chemical properties of two polluted and unpolluted water bodies at Assiut, Egypt. A total of 169 species related to 64 genera of epiphytic microalgae were recorded. The most dominant algal group was Bacillariophyceae (43.2%), followed by Chlorophyceae (34.91%), Cyanophyceae (20.71%) and Euglenophyceae (1.18%). The total number of epiphytic algae fluctuated between 11.1 × 104 ind.g-1 plant dry wt. on Phragmites australis in summer at Nazlet Abdellah (polluted site) and 10.02 × 107 ind.g-1 plant dry wt. on Myriophyllum spicatum in winter at El-Wasta (unpolluted site). Some epiphytic microalgae were dominant as Pseudanabaena limnetica, Calothrix braunii, Scenedesmus acutus, and Ulnaria ulna. Others were specific on certain macrophytes as Aphanocapsa thermalis and Ulothrix sp., which grow on Phragmites australis, while Synechocystis minuscula attached itself on Myriophyllum spicatum. Analysis of PERMANOVA showed that the most important factors that induced the variation in epiphytic microalgae were the temporal variation and host plant. Water temperature, pH, nitrate, chloride, phosphate and total dissolved salts were the highest abiotic factors correlated with the variation in composition of epiphytic microalgae

Culture, Income, and CO2 Emission

Given the devastating effects of global warming, the problem of human-induced climate change, and in particular carbon dioxide emissions, has been high on the global policy agenda. In this study, we examine the relationship between national culture, carbon dioxide emissions, and economic growth in the framework of the Environmental Kuznets Curve (EKC). Applying system GMM panel estimator across 69 developed and developing countries, we confirm the existence of EKC and show that culture significantly affects the income-emission relationship. Moreover, the effects of the six cultural dimensions on EKC can be collapsed into two: (i) masculinity, power distance and indulgence move the EKC upward and shift the income turning point to the left; and (ii) individualism, uncertainty, and long-term orientation move the EKC downward while shifting the income turning point to the right. The impact of culture on EKC remains also robust for alternative specifications. Future policy and global initiatives in sustainable development should incorporate the multidimensional impact of culture on national behavior towards environment and economic growth, a relationship that has been largely ignored in economic decision-making models

Enhancing Water Productivity of Alfalfa (Medicago Sativa) Under Centre Pivot Irrigation System

Abstract: The objective of this study was to evaluate water productivity of alfalfa (Medicago sativa) under centre pivot irrigation system. The experimental works were conducted at three centre pivot irrigation projects (Indian, Arab Authority for Agricultural Investment and Development (AAAID) and Sedonix projects) located at Khartoum State during the period from April 2011 to April 2013. In each project, three irrigation systems were randomly selected for the study treatments. Crop water requirement was obtained using CROPWAT 8 computer model. The parameters tested were Christiansen coefficient of uniformity (Cu%), distribution uniformity (Du%), Scheduling uniformity (Su) and Water productivity (kg/m3). SAS (statistical package) was used to analyze the data. The variations among means were checked by the least significant difference (LSD). The results showed that Cu%, Du%, Su and water productivity significantly affected by the management practices in different irrigated projects. Sedonix project gave the highest values of hydraulic characteristic (Cu 85%, Du 81% and Su 1.23) while AAAID project recorded the lowest values (Cu 74%, Du 70%, Su 1.43). Water productivity significantly increased in Sedonix project (0.45 kg/m3/cut) followed by Indian projects (0.38 kg/m3/cut) and AAAID which ranked the least (0.27 kg/m3/cut). It is concluded that for improvement water productivity; proper technical guidelines for system management, operation and scheduling should be followed

ANEMIA IN PREGNANT WOMEN OF EASTERN SUDAN

 It has been estimated that over half of all women in the world experience anemia during pregnancy with 95% occurring among women in the developing counteries1. Many risk factors for anemia were identified in pregnancy 2. In a community-based study we have recently reported that around 26% of the women of Eastern Sudan were anaemic, as well as we have shown that anaemia is one of the risk factors for deep venous thrombosis in the Sudanese pregnant women 3,4. However no proper published data exist for anaemia, its epidemiology and the risk factors during pregnancy in Sudan.   We performed a prospective study to estimate the incidence, timing and the risk factors for anemia during pregnancy in a population of Sudanese women in Eastern Sudan. Pregnant women attended antenatal care clinic at New Halfa Teaching Hospital were approached for participation in the study during September- November 2003. After a verbal consent a fixed questionnaire containing sociodemographic characters, obstetrical history as well as the known risk factors for anemia was filled (history of abortion, lack of iron supplementation, oral contraceptive pills (OCP) use and pica). All patients were examined clinically to detect signs of anemia–if present. Spleen was palpated and the gestational age was confirmed by Ultrasound in cases of discrepancy. Hemoglobin was estimated by colorimeter (WPA, U.K) and blood films for malaria were prepared using Geimsa stain. A well-trained technician who was blinded about the women’s data did the laboratory investigations. Data was entered in microcomputer using SPSS for windows the students, t-test, compared the mean ± SD of the age, gestational age, and hemoglobin. Relative risk was calculated for the possible factors. P < 0.05 was considered significant. &nbsp

EMPIRICAL EVIDENCE ON SYSTEM IMPLEMENTATION FAILURES IN THE ENTERPRISE RESOURCE PLANNING DEVELOPMENT PROCESS

Enterprise resource planning (ERP) relates primarily to software for business management, which consists of many modules that are essential for the growth and survival of various types of companies and organisations. By allowing faster supply chain management, the incorporation of similar business applications in an organisation will bring considerable advantages to the organisation. In order to increase business efficiency, ERP implementation helps businesses to adapt and customise information flows and automate business processes. The implementation of the system was reviewed with sufficient literature to substantially support the significance of arithmetic and logical principles and basic programming errors, including programme typographical errors, syntax error detection, and programme output process errors. Furthermore, the declaration of variables, the significance of modularisation and the need to support accessories, the accessibility of library files and the importance of frameworks have been discussed. In order to recognise framework implementation deficiencies in the ERP development process, improvement of coding formatting and significance of coding syntax were also critically checked with appropriate literature. JEL: L53; O10; L22 Article visualizations