A new radio navigation system for aircraft blind landing is proposed. This system is based on measuring the phase shifts of signals received from four ground transmitters (antennas), placed on corners of the runway strip. The received signals phase shifts provide distance measurements accuracy in millimetres. The reception of these signals is made on the onboard antenna located on the aircraft. Three ground antennas out of the four will be sufficient for determining the location of the aircraft. As a result of the analysis, the coordinates of the onboard antenna, the coordinates of the centre of mass of the aircraft, and axis coordinate of the aircraft determined with respect to the runway coordinate system.

This work describes the architecture and design of an onboard digital receiver of the phase radio-navigation system for aircraft blind landing proposed in [1]. The proposed onboard digital receiver is a special case of a multi-channel narrowband digital receiver concept. The purpose of this receiver is to receive eight different RF frequencies (in four pairs) range from 960 MHz to 963.003749941 MHz, carry on them the required analogue and digital signal processing techniques to evaluate their phase shifts and then the difference phase shifts between each pair of them. The phase measurements lead to determination of the location of the aircraft with respect to the touch point on the runway with accuracy in millimetres.

In this work, the estimation capacity of the response surface methodology (RSM), in the catalytic naphtha reforming to enhance the octane number of reformats via isomerization reaction pathway and minimize the aromatization activity over tri-metallic modified Pt-Re/Al2O3 catalyst were investigated by applying Design of experiment (DOE). The parent bimetallic catalysts were modified using a relatively inactive metal (Sn) by means of employing non-conventional method of anchoring technique called controlled surface reaction (CSR) method in order to favor the intimate contact of Sn with the active phase to suppress the metallic character of Pt metal. The correlations between RON, aromatization and isomerization activities with three reaction variables namely temperature (480-510oC), pressure (10-30 bar) and space velocity LHSV (1.2-1.8 h-1) were presented as empirical mathematical models via reforming of a complex mixture (80oC -185oC). Numerical results indicated that the minimum aromatization activity was 20% when reaction temperature was 460oC and pressure of 35 bar. Results also show that maximum isomerization activity of 58% was achieved when pressure is 30 bar and space velocity is 1.8 h. it has been found that optimum value of RON = 89 was attained at 449.9oC, 32 bar and 1.7 h-1. However, high operating pressure and low reaction temperature significantly decrease the aromatization activity coupled with substantial decrease in RON which can be enhanced by producing high yield of isomers.  

Using information and communication technology to engage Libyan University students in the English Culture, Rewaq Almarefe –scientific journal, third and fourth issues 2015

This paper presents the findings of the investigation of ERP implementation. It highlights the challenges and experiences of Libyan Companies in ERP implementation. The success factors, failures are analyzed and have proposed recommendations to improve ERP implementation. The adopted research approach covers both quantitative and qualitative methods. The data collection methods used were questionnaires, 75 out of 100 questionnaires were returned sufficiently completed. The paper contributes to discussion based on literature review and ERP implementation in developing economics. The results of the study revealed that the majority of the respondents are aware of what ERP is all about, and they are also aware about critical issues in the implementation of ERP. The findings revealed that: failure to select committees needed for the successful implementation of ERP, an inadequate financial budget and resources, and failure to make knowledgeable input at the planning stage can be problems to successful implementation of ERP. The conclusions suggest for addressing challenges and problems in the ERP implementation. Enough time should be provided to project team, show leadership in change management and sufficient resources should be allocated for the proper implementation of ERP.

It has become firmly established the productivity is the real source of and important for economic growth of any country; it has an essential role in the economies of developed and developing countries alike. It allows the nation to raise its standard of living, to support such social goals as education and health care, and to contribute to other aspects of the general welfare; it is an essential underpinning of the nation's security (Stupak and Leitner, 2001). Increased productivity is the key to economic progress, where the standard of living of communities and income levels depend on the progress of the level of productivity; higher levels of productivity in economies lead to increased rates of growth and prosperity (Seid, 1996).

Abstract: Monitoring the concentrations of heavy metals in natural and waste water at and below the level of their maximum permissible concentrations is an urgent environmental problem. Hence, new procedures for the preconcentration of heavy metals with their subsequent determination by different methods are required. Along with other sorbents, significant attention is attracted to polymer chelating sorbents, which provide individual or group extraction of trace elements, eliminate matrix effects, and provide high concentration factors. The effect of the various parameters such as electrochemically and chemically synthesis methods, physical oxidation state of the polymer, polymer thickness, solution pH and metal ion concentration on the adsorption, kinetics and efficiency were investigated. The results showed a vary broad concentration range of the heavy metals from (0.05 to 10 mg/L) can be adsorbed on different kinds of polymers at different pH values and different efficiently. The adsorption capacity of the polymer to different concentrations of heavy metals was evaluated as the milligram of metal ions by one gram of various forms of the polymer. The DC conductivity measurements were also employed on the solid polymer before and after adsorption of metal ions. The experimental adsorption date was fitted to different mathematical isotherms to estimate the binding constant of heavy metals with the polymer in both single and mixed ion solutions. The method provides the extraction of analytes from natural water of complex composition containing high concentrations of alkali, alkaline-earth and other elements and is characterized by rapidly, selectivity, low detection limits, and a high reproducibility of the results. The relative standard deviation is 2-4%. The technique was test with real waste water samples.