In this study, the production of ethylene and hydrogen is studied via the thermal cracking of ethylene in an ethylene plant based in Libya. During the process of thermal cracking, a mix of naphtha and steam is input into tubes that are directed to the naphtha main line. The utilization of steam is generally used because of the partial removal of coke which has undesirable effects on the process. The coke accumulation on the coils, or tubes, result in a decrease in pressure and also reduction in the yields produced. In this work, the naphtha thermal cracking process is both designed and solved numerically. A thorough comparison of the design results and the data extracted from the experiment reveal that the design may predict the overall process precisely. Also, the direct effects of CO2 are studied with regard to the accumulation of coke. Based on the results of two separate scenarios, the process of thermal cracking with the CO2 is beneficial to the overall process due to the higher yield of ethylene and propylene, and less accumulation of coke, and, in turn, less thickness on the coils inside the furnace. The results from the simulation show that the run time, or run length, of the furnace with the addition of CO2 becomes almost two times as the run time with adding steam. Based on these results, this study has proven to be worthy to explore, and the addition of CO2 has been observed to have noticeably positive results on the thermal cracking process.

This paper presents an application of a condition-monitoring system (CMS) based on a polynomial regression model (PRM) to study the influence of heat loss on a wind generator’s temperatures. Monitoring the wind generator temperatures is a significant for efficient operation, and plays a key role in an effective CMS. Many techniques, including prediction models can be utilized to reliably forecast a wind generator’s temperature during operation and avoid the occurrence of a failure. PRMs are widely used in situations when the relationship between the response and the independent variables are curve-linear. These techniques can be used to construct a normal behavior model of an electrical generator’s temperatures based on recorded data. Many independent variables affect a generator’s temperature; however, the degree of influence of each independent variable on the response is dissimilar. In many situations, adding a new independent variable to the model may cause unsatisfactory results ;therefore, the selection of the variables should be very accurate. A generator’s heat loss can be considered a significant independent variable that greatly influences the wind generator with respect to the other variables. A generator’s heat loss can be estimated in intervals by analyzing the exchange in the heat between the hot and cold fluid through the heat exchangers of wind generators. A case study built on data collected from actual measurements demonstrates the adequacy of the proposed model. 

Abstract

Fuel flexibility will drive the energy demand in the near future. The use of different syngas compositions from various sources will play a major role in the global fuel mix. CO2 in the blends will also be added as a mechanism to improve carbon capture and storage technologies. However, this can trigger instabilities such as thermoacoustics, flashback, autoignition and blowoff. In terms of blowoff, the phenomenon is still not entirely understood. This project presents a series of experiments to determine the behaviour and impact on the blowoff process at various swirl numbers, nozzle geometries and gas compositions. The Central Recirculation Zone was analyzed just before blowoff. The results show how the strength and size of the recirculation zones are highly influenced by these parameters. However, it seems that the CRZ dimensions/strength does not play an important role in the blowoff, whilst the composition of the mixture shows high correlation. Nevertheless, the CRZ intensity using these compositions can increase residence time, important for combustion improvement of other blends.

The objectives of this study (baseline study, n = 20) were to implement Matlab procedures for quantifying selected static balance variables, establish baseline data of selected variables which characterize static balance activities in a population of healthy young adult males, and to examine any trial effects on these variables. The results indicated that the implementation of Matlab procedures for quantifying selected static balance variables was practical and enabled baseline data to be established for selected variables. There was no significant trial effect. Recommendations were made for suitable tests to be used in later studies. Specifically it was found that one foot-tiptoes tests either in static balance is too challenging for most participants in normal circumstances. A one foot-flat eyes open test was considered to be representative and challenging for static balance.

This study is aimed at investigating the interactive effect of reaction variables on the composition and octane number of reformat in catalytic naphtha reforming gasoline fuel. The relationship between aromatization activity and RON, with three reaction variables, namely temperature (480–510 °C), total pressure (10–30 bar) and space velocity LHSV (1.2–1.8 h⁻¹) were presented as empirical mathematical models. Experiments were performed based on the central composite rotatable design and analyzed using response surface methodology (RSM) and canonical analysis. First, the equation models are used to predict RON and aromatization activity as responses. Second, the regression analysis of RON and aromatization activity equations is obtained from the output of these developed models. Finally, the RSM is used to optimize these regression empirical models. R ² = 88.5 % for RON and 80.5 for the aromatization activity showed that RSM models fitted well with the observed data and considered to be accurate and available for predicting responses. The temperature and total pressure are the most effective variables as a linear (X 1 , X 2) terms and have a significant role in the responses. Numerical results also revealed that the maximum predicted RON of 105 was attained at optimum reaction temperature of 515 °C, operating pressure of 17 bar and LHSV of 2.0 h⁻¹.

The construction industry has become more complex due to changes in technology and the greater emphasis placed on satisfying green requirements. The design phase is the most important phase in determining the green performance of building projects. The performance of the design team is crucial. The selection of a design team should be based on a set of criteria. Therefore, a competent design teams is required to have a good understanding of environmental issues. Design teams require a range of competences such as skills of environmental assessments, initiatives and environmental background as the basis for design decisions. In addition, success of building projects greatly depends on the client’s performance. The performance of clients is crucial since decisions made will influence the overall project performance. The quality of clients’ representatives has potential influence on design team performance. In designing green buildings client’s attributes are critical factors to high performance of building projects. The propose of this study to identify the significant associations between variables of design team attributes and client qualities. To achieve mentioned aim a questionnaire survey was conducted to collect data required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used for Rasch modeling to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. The results indicate that the influence of Clients’ Qualities on Design Team 

The main purpose of this research is to construct a generic model for successful implementation of Total Quality Management (TQM) in Oil sector, and to find out the effects of this model on the organizational sustainability development (OSD) performance of Libyan oil and gas companies using the structured equation modeling (SEM) approach. The research approach covers both quantitative and qualitative methods. A questionnaire was developed in order to identify the quality factors that are seen by Libyan oil and gas companies to be critical to the success of TQM implementation. Hypotheses were developed to evaluate the impact of TQM implementation on O SD. Data analysis reveals that there is a significant positive effect of the TQM implementation on OSD. 24 quality factors are found to be critical and absolutely essential for successful TQM implementation. The results generated a structure of the TQMSD implementation framework based on the four major road map constructs (Top management commitment, employee involvement and participation, customer-driven processes, and continuous improvement culture).

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Aspects related to robustness of steel frameworks with semi-rigid steel and steel-concrete composite joints are dealt with. Experimental investigations were carried out for sub-frames fabricated in technical scale. Pushdown tests for steel subframes simulated the joint ability to transfer the bending moment and axial force under a column loss scenario. Tests on composite sub-frames were arranged in two stages. The first one was related to a service stage when the slab was under a gravity load and the column to be removed supported. The gravity load was sustained in the second stage when a column loss scenario was simulated. Experiments have shown that composite flush end-plate joints may not be robust enough since their low strength under sagging bending, despite of good ductility, does not allow for the redistribution of internal forces in order to achieve the equilibrium in the residual state after static column removal. Contrary, symmetrical steel and composite joints with extended end-plates on both sides of beam flanges seem to be more robust, despite of their lesser ductility. Robust bending behaviour is possible because extended end-plate joints exhibit a better balance between the strength and rotation capacity that allows to achieve the equilibrium state in case of a static column loss event.

Cleavage fracture of the medium carbon V-microalloyed steel with structure consisting of acicular ferrite, pearlite and grain

boundary ferrite has been investigated by means of four-point bending of the notched samples at -196°C. It was found that

cleavage fracture initiation has not been related to the coarse second phase particles cracking. Calculated values of the effective

surface energy of 49 J/m2 and critical cleavage fracture stress normalized by yield stress of 1.84 are in agreement with the results

for the steels with ferrite-pearlite and bainite structures.

The purpose of this paper is to investigate the quality management dimensions, based on Deming Management Model, in Oil industry in Libya. Questionnaire, semi structured interview and open interview were used to collect data from random sample of 42 qualityrelated managers from the Libyan Oil industry. Forty-five questionnaires were provided by hand to quality-related managers from the Libyan Oil companies. A total of 42 were returned sufficiently completed, that gave us a response rate of approximately 93.33%. The regression analysis indicated that these organizations implement total quality management practices. The findings suggest that an integrated approach is required to implement the total quality management practices in order to realize strategic quality objectives. This research is subject to the normal limitations of survey research. The data is based on individual opinion of quality related managers, which may bring in some bias. Further research needs to be done to advance our knowledge and to further support the findings. For instance, a larger sample size and more items per Deming principle may be used in future studies to duplicate these results and to increase the internal consistency of the scales. Deming Management Model is applied to one industry in this study. Therefore, to establish the generalization of the Model within the context of Libya, it needs to be tested in other industries setting, both in public and private sectors. The study extends the applicability of the Deming Management Model to a new industry and country. Collectively, the results of the research provide more understanding of issues relating to quality management in developing countries and a framework for enhancing organizational effectiveness. Therefore, the research can make a useful contribution.