Now showing items 202-221 of 221

    • Thermal and catalytic cracking of petroleum residue oil 

      Syamsuddin. Y.; Hameed, B. H.; Zakaria, R.; Muhamed, A. R. ( Qatar University , 2005 , Article)
      Thermal and catalytic cracking over synthesized nickel-molybdenum supported on aluminum borate (NiMo/AB) catalysts were studied. A series of aluminum borate supports with various aluminum borate (A/B) weight ratios were ...
    • Three Dimensional Analysis Of Skeletal Structures Considering Cracking 

      El Hadidi, M. T. ( Qatar University , 1992 , Article)
      A three dimensional computer model has been developed to analyze space structures containing cracked members. A new stiffness matrix for cracked space members has been obtained. This model takes into consideration crack ...
    • Three Dimensional Analysis Of Space Imageries 

      Diefallah, M. A. M. ( Qatar University , 1994 , Article)
      Space imageries with their low costs and availability for every one, provide a good opportunity for topographic mapping of unmapped or poorly mapped areas around the world particularly in the developing countries. The ...
    • Throughput-Delay Performance Analysis Of Ssma Packet Radio Network 

      El Jaafreh, Yousef G. ( Qatar University , 2000 , Article)
      Multiple access communication accommodates a large population of relatively uncoordinated users of a common spectral allocation in the same and neighboring geographical areas with the number of simultaneous users proportional ...
    • Time-Optimal Control Of High-Speed Flexible-Robot Arm Using PD Algorithms 

      Fanni, Mohamed; Abdel-Rahman, Tarek; Al-Salem, Nabeel ( Qatar University , 2000 , Article)
      This paper addresses utilization of proportional-plus derivative (PD) control algorithms for time-optimal control of flexible-robots. Flexibility is modeled using one mode of vibration with negligible structural damping. ...
    • Traffic Generation And Parking Demand Of The Qatar International Squash And Tennis Centre 

      Bartlett, Robert E. ( Qatar University , 1993 , Article)
      In early 1992 the Government of the State of Qatar decided to construct a new squash and tennis centre. Ministry of Municipal Affairs and Agriculture (MMAA) staff made an assessment of the centre's probable traffic generation ...
    • Transmission Of Compressed Video Signals Through A Spread Spectrum Channel 

      Al Asmari, Awad Kh.; Kwatra, C. ( Qatar University , 2001 , Article)
      This research studies the feasibility of devising a compression scheme for video sequences that is robust to fading errors in a spread spectrum environment. Schemes like subband coding and pyramid coding are inherently ...
    • Ultrasonic C-Scan Inspection Of Composite Materials 

      Fahr, A. ( Qatar University , 1992 , Article)
      Ultrasonic technique using an automated C-scan has been established as the primary inspection method for composite materials. In this paper, the principles of ultrasonic inspection, the type of defects that may be generated ...
    • Ultrasonic Characterization, Tensile Testing And Thermal Properties Of Y Irradiated Low Density Polyethylene, Fb 5005 

      El Qassem, Zuhair Mohamed; Kassem, Mohamed El-Said ( Qatar University , 1997 , Article)
      Ultrasonic pulse-echo technique, tensile testing and thermal gravimetric analysis have been utilised to characterise and monitor the effect of y irradiation on the physicomechanical properties of low density polyethylene ...
    • Ultrasonic Pulse Velocity Versus Strength For Concrete In Qatar 

      Abdul Salam, M. A. ( Qatar University , 1992 , Article)
      Compressive strength of concrete is widely accepted as a characteristic property indicating and representing its quality. The accuracy of both ultrasonic and mechanical strength is discussed and the advantages of ultrasonic ...
    • Unrelated Machines Scheduling With Machine Eligibility Restrictions 

      Al Salem, Ameer; Armacost, Robert L. ( Qatar University , 2002 , Article)
      In this paper we present a new heuristic algorithm to minimize the makespan for scheduling jobs on unrelated parallel machines with machine eligibility restrictions ( R^ I M .1 C^^). To the best of our knowledge, the ...
    • Unsteady State Process Computations On Spreadsheets 

      Javed, K. H.; Ahmad, Shamim ( Qatar University , 1993 , Article)
      Spreadsheets are becoming increasingly popular, as a useful tool, for making process engineering calculations. This paper shows the use of spreadsheets for computations of an unsteady state process described by ordinary ...
    • Unsteady State Two Phase Flow Pressure Drop Calculations 

      Ayatollahi, Shahaboddin ( Qatar University , 1992 , Article)
      A method is presented to calculate unsteady state two phase flow in a gas-liquid line based on a quasi-steady state approach. A computer program for numerical solution of this method was prepared. Results of calculations ...
    • Unsteady-State Interphase Diffusion 

      Chebbi, R. ( Qatar University , 1993 , Article)
      This study is concerned with the problem of unsteady interphase diffusion for multicomponent dilute solutions. An integral technique, based on an approximate boundary-layer approach is used. Results are in good agreement ...
    • Use Of Cement By-Pass Dust In Soil Stabilization 

      Taha, Ramzi; Al-Rawas, Amer; Al-Harthy, Ali; Al-Siyabi, Hilal ( Qatar University , 2001 , Article)
      Cement by-pass dust (CBPD) or cement kiln dust (CKD) is a by-product of the manufacture of Portland cement. It is generated during the calcining process in the kiln. Lime (CaO) constitutes more than 60% of CBPD composition. ...
    • Use Of Spreadsheets For Rainfall-Runoff Calculations 

      El Bahrawy, Aly N. ( Qatar University , 1996 , Article)
      The nature of rainfall-runoff calculations necessitates the use of different equations for calculating losses and several response functions to route the effective rainfall hyetograph through the catchment. The ...
    • Utilization Of The Desired Machined Surface Roughness Number As A Criterion For Cutting Tool Replacement Strategy 

      Roushdy, E. H. ( Qatar University , 1992 , Article)
      Current research in metal removal processes does not provide predictive relationships vitally needed for the selection of machining conditions or specifying limitations on the cutting tool and work material responses. ...
    • Viscosity Of Hydrocarbon Liquids Saturated With Gas 

      Al Harbi, Dulaihan K. ( Qatar University , 1995 , Article)
      Experimentally measured kinematic viscosities are reported for benzene, cyclohexane and n-heptane saturated with hydrogen, nitrogen and carbon dioxide. A Zeitfuchs cross-arm viscometer suspended in a unique design ...
    • The Voltage Collapse Problem Based On The Power System Loadability 

      Alammari, R. A. ( Qatar University , 1997 , Article)
      This paper addresses the problem of voltage instability at which the power system reaches its maximum admissible load. A voltage collapse proximity indicator (VCPI) is derived and its performance is investigated. The VCPI ...
    • Voltage Stability Margin Identification Using Local Measurements And Linear Kalman Filter 

      Alammari, R. A. ( Qatar University , 2002 , Article)
      Voltage stability investigation is of a great importance for long-term electric load expansion as well as power system operation. This paper presents a new algorithm for identification of voltage instability in a specified ...