Abstract—This work reports on the steady-state analysis and control strategies of switched reluctance motors (SRMs). For this purpose, a theoretical background is introduced and a mathematical model is derived. A Matlab code has been written to determine the motor magnetic characteristics. The inductance profile has also been determined and from which the induced voltage constant, which is used to find the electromagnetic torque, is obtained. A low-performance voltage control strategy is applied to the motor. Simulation results are given to evaluate the overall system performance

Abstract

There is much discussion in the scientific literature and concern in the wider community about climate

change, recent climate analyses indicate that the magnitude of 21st Century warming is likely to have been the

largest of any century for the last 1000 years over the northern hemisphere. All the IPCC's four reports between

1990 and 2007 concluded that we cannot expect stable climate in the future and we should prepare scenarios

and strategies for the survival of humankind under the conditions of forthcoming global change. In this study,

the applicability of the statistical downscaling model (SDSM) in downscaling temperature in Misurata area -

Libya, was investigated. The investigation includes the calibration of the SDSM model by using large-scale

atmospheric variables encompassing NCEP reanalysis data, the validation of the model were measured daily

temperature data (1961-1990) using independent period of the NCEP reanalysis data and the general circulation

model (GCM) outputs of scenarios A2 and B2 of the HadCM3 model. The model is calibrated and applied at a

daily time series, even though the output is monthly and the prediction of the future regional maximum and

minimum temperature scenarios for three time windows: 2011-2040, 2041-2070 and 2071-2099. The results showed

that: The statistical downscaling model (SDSM) was able to describe the basic statistical properties of daily

minimum and maximum temperature in the period of record, suggesting that it could be used to predict future

trends. Trend analysis in the study area showed an increase in average annual and monthly temperature,

compared to the baseline period for both HadCM3A2a and HadCM3B2a scenarios in both the dry and wet

seasons. However, this increase is higher in dry months than wet months for all future time horizons and for

both HadCM3A2a and HadCM3B2a scenarios. Thus there is likely to be a significant warming in local surface

temperature, which is enough for a significant change on the energy balance and is likely to impact water

availability.

Key words: Statistical downscaling model SDSM Intergovernmental Panel on Climate Change

IPCC General circulation model GCM Special Report on the Emission Scenarios SERS

Maximum and minimum temperature Misurata area Libya

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).

• English
• Polish

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.

Abstract –Wings are the main lift generating sources for any aerospace vehicle. The performance of an airborne vehicle largely depends on its wing design. That is why it is important to understand and be able to calculate wing characteristics in every design process. The analysis of the 3 dimensional transonic flow over ONERA M6 wing at two Mach numbers and angles of attack from 0 to 6 degrees and operating Reynolds number of 11x106 is presented. Computational Fluid Dynamics CFD as a widely used analysis and design tool still need to be validated by comparison with experiment. Ansys/Fluent is used to solve the governing equations with k-SST turbulence model. The validation is done through comparing pressure coefficient distributions over wing surfaces at seven span locations, with experimental measurement . Wing geometry is successfully modeled inside Ansys geometry modeler and unstructured mesh is generated with Ansys mesh modler. Results show good agreement with experimental data at Mach number of 0.84 and 3 degrees angle of attack. On the other hand, as Mach number and angle of attack are increased, numerical results show poor accuracy in capturing shock wave position. 

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.