Abstract

The main purpose of catalytic reforming unit is to upgrade low-octane naphtha to high-octane gasoline. In this work, the estimation capacities of the response surface methodology (RSM) and artificial neural network (ANN), to determine the research octane number (RON) of reformates produced from the catalytic naphtha reforming unit were investigated. The article presents a comparative study and combined application between response surface methodology (RSM) and artificial neural networks (ANN) based on design of experiment (DOE) strategy in the modeling and prediction of the research octane number (RON). In this study, DOE⿿CCRD full factorial design was incorporated into the ANN methodology, so the need of a large quantity of training data was avoided. ANN methodology showed a very obvious advantage over RSM for both data fitting and estimation capabilities. Based on the results of analysis of variance (ANOVA), a multiple determination coefficient of 0.8 and 0.99 were obtained for both RSM and ANN respectively. It has been found that by employing RSM approach coupled with ANN model based on DOE strategy, the visualization of the experimental points in three dimensional spaces can disclose qualitatively and quantitatively the activity relationships. This approach of combination of RSM⿿ANN⿿DOE has revealed its ability to solve a quadratic polynomial model involving solving, optimization, complexity and difficult relationships especially nonlinear ones may be investigated without complicated equations involved. The study revealed that, the maximum RON of 88 was obtained at the optimum conditions offered by RSM. Furthermore, at the optimal conditions of (T = 521 °C, P = 37.6 bar, LHSV = 2.02 h⿿1), the maximum RON of 98 was obtained for the ANN model. However, the models were implemented for the construction of 3D response surface plots from the ANN and RSM models in order to show the most effective variables as well as the effects of their interaction on the research octane number.

Abstract. Economic development in line with improvement life style is the ultimate purpose in a modern society. Most low-income and developing Asian countries are facing a number of challenges with respect to sustainable waste managing from their industrial activities. On the other hand, these countries aim to be industrialized and consequently, generate huge industrial solid wastes with an increasing trend. Land fill disposal is the most practiced method for handling industrial solid wastes among Asian countries. It was pointed out that illegal industrial waste disposal has increased sharply due to the land scarcity. Meanwhile, there is less attention to practicing waste minimization as a sustainable and effective strategy for controlling industrial solid wastes in developing Asian countries. The lack of significant factor such as strict regulation and strong enforcement, awareness and knowledge, enough funding, technology and skilled manpower are found as the main hindrances to sustainable industrial waste management among Asian countries. This paper is a mini review paper that aimed to compare the current practicing of different waste management options by industries in Asian countries by highlighting challenges and approaches in sustainable solid waste management.

Keywords: asian countries, waste minimization, industrial wastes, landfill disposal, sustainable waste management, hindrances 

Abstract:

A new trend in catalytic naphtha reforming requires the decrease of aromatics hydrocarbons particularly benzene in reformate, while maintaining high octane rating. At present, production of reformulated gasoline with low content of benzene is one of the main challenges in the transportation fuel industry. In the catalytic reforming of realistic naphtha over bi-functional Pt-Re-S/Al2O3-Cl catalysts the: (i) liquid yield (C5 +), (ii) yield of aromatics, (iii) iso paraffin/aromatics ratio, (iv) side reactions (hydrocracking, hydrogenolysis, coking) as responses can be altered by controlling the independent reaction parameters (Temperature, Pressure, Liquid Hourly space velocity (LHSV), Hydrogen to hydrocarbon ratio (H2/HC ratio), chlorine and the addition of different promoters to the catalyst (Re, Sn, Ir, etc). In the present report, a quadratic polynomial equation for the responses Research Octane Number (RON), Neglect this statement as these models has been removed were obtained by multiple regression analysis and tested using analysis of variance (ANOVA) with 95% degree of confidence. The validation of experimental data was confirmed with the predicted model. The results showed that the reaction temperature and the total operating pressure are the key variables that have the main influence on naphtha reforming reactions by the synergistic effect of linear term (X1, X2), which is in a good agreement with the experimental data reported previously in the literature.

Keywords: Catalytic naphtha reforming, Pt-Re bifunctional catalyst, Research octane number, Response surface methodology (RSM), Central composite design, Optimization. 

To reveal the prior-austenite grain boundaries in micro-alloyed steels there is different techniques. This study has been carried out over a wide range of temperature (950-1150 οC) and it has been found that the tested procedure based on the combination of heat treatment and thermal etching (TE) method give excellent results for the Titanium and Titanium free medium carbon micro-alloyed steels at all the austenitization conditions tested.

The critical key success factors, which have to be targeted with appropriate change management, are the user acceptance and support of a new Enterprise Resource Planning (ERP) system at the early implementation stages. This becomes even more important in Arab context where national and organisational culture with a different value and belief system, resulting in different management styles, might not complement with Western business culture embedded in the predefined standard business processes of existing ERP packages. This study explains and critically evaluates research into national and organizational culture and the influence of different national cultures on the implementation and reengineering process of ERP packages in an Arab context. Using a case study, realized through a quantitative survey testing five of Martinsons’s and Davison’s propositions in a Libyan sample company, confirmed the expected results from the literature review that culture has an impact on the implementation process and that employee empowerment is an unavoidable consequence of an ERP implementation.

The purpose of this paper is to find out the impact of Quality Management System (QMS) ISO/IEC 17025: 2005 certification audit on company’s Performance. Libyan petroleum Institute has been certified ISO/IEC 17025: 2005 for 8 years. Therefore, it is necessary to study and analyze the impact of that certification on its performance. Survey study has been done by distributing a questionnaire by handing it personally to qualified staff in the 15 accredited laboratories in the institute. The response rate was 66.6%. The statistical operations with the results of analytical study have been done to achieve the goal and objectives of the research. Finally, ISO/IEC 17025: 2005 certification audit is found to have a positive effect on the institute’s performance.

One of the challenges in data mining practices is that the datasets vary in complexity and often have different characteristics such as number of attributes, dependent variables characteristics etc. In terms of regression problems, the features that describe the dataset will vary in their complexity, sparseness verses coverage in relation to the decision space, and the number of outcome classes. Fuzzy Decision trees are well-established classifiers in terms of building robust, representative models of the domain. In order to represent different perspectives of the same domain, fuzzy trees can be used to construct fuzzy decision forests to enhance the predictive ability of singular trees. This paper describes an empirical study which examines the applicability of fuzzy tree regression forests to seven different datasets which have complex properties. The relationship between dataset characteristics and the performance of fuzzy regression tree forests is debated.

Digital libraries support the transition of academic

institutions towards digital universities, and introducing ETD digital

repositories is believed to be a step in this process. This paper

describes an ETD Digital Library project at the Libyan Academy of

Graduate Studies. The project aims to build digital library for theses

and dissertations (ETD). This work is a project for the first

institutional ETD digital library in the Libyan country. The

researchers developed a system based on Greenstone open source

system for building ETD digital library. A metadata for theses and

dissertations was developed in this research. The paper addresses

issues related to project design, development and user satisfaction.

Conclusions highlighted some important lessons learned to date.

Learning is an understanding of how the human brain is wired to learning rather than to an approach or a system. It is one of the best and most frequent approaches for the 21^st century learners. Micro learning is more interesting due to its way of teaching and learning the content in a small, very specific burst. Here the learners decide what and when to learn. Content, time, curriculum, form, process, mediality, and learning type are the dimensions of micro learning. Our paper will discuss about micro learning and about the micro-content management system. The study will reflect the views of different users, and will analyze the collected data. Finally, it will be concluded with its pros and cons.

Abstract

Swirl stabilized flows are the most widely deployed technology used to stabilize gas turbine combustion systems. However, there are some coherent structures that appear in these flows close to the nozzle whose occurrence and stability are still poorly understood during transition. The external recirculation zone and the Precessing Vortex Core to/from the Coanda effect are some of them. Thus, in this paper the transition of an Open Jet FlowMedium Swirl flow pattern to/from a Coanda jet flow is studied using various geometries at a fixed Swirl number. Phase Locked Stereo Particle Image Velocimetry and High Speed Photography experiments were conducted to determine fundamental characteristics of the phenomenon. It was observed that the coherent structures in the field experience a complete annihilation during transition, with no dependency between the structures formed in each of the flow states. Moreover, transition occurs at a particular normalized step size whilst some acoustic shifts in the frequencies of the system were noticed, a phenomenon related to the strength of the vortical structures and vortices convection. It is concluded that a transient, precessing, Coanda Vortex Breakdown is formed, changing flow dynamics. The structure progresses to a less coherent Trapped Vortex between the two states. During the phenomenon there are different interactions between structures such as the Central Recirculation Zone, the High Momentum Flow Region and the Precessing Vortex Core that were also documented.