King Fahd University of Petroleum and Minerals

About: King Fahd University of Petroleum and Minerals is a education organization based out in Dhahran, Saudi Arabia. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 7603 authors who have published 24030 publications receiving 443803 citations. The organization is also known as: College of Petroleum and Minerals.

Factors considered in tendering decisions by top UK contractors

Abstract: Decision-making involves a process by which a choice is selected from a number of options. Bid decisions by contractors are complex due to uncertainty about many factors affecting their outcomes. This study was able to identify, through a questionnaire survey, 55 factors characterizing the bid decision-making process. The questionnaire was mailed in August 1990, to 300 top contractors in the UK. The results indicate that several factors are considered equally important for bid/no bid and markup size decisions. Other factors are seen to have considerable importance for one decision but not for another. The need for work, the number of competitors tendering, and the amount of experience on such projects are identified as the top three factors that affect a contractor's decision to bid for a project. The degree of difficulty, the risk involving owing to the nature of the work, and the current work load are the highest ranked factors affecting markup size decisions.

Spark plasma sintering of metals and metal matrix nanocomposites: a review

Abstract: Metal matrix nanocomposites (MMNCs) are thosemetal matrix composites where the reinforcement is of nanometer dimensions, typically less than 100nm in size. Also, it is possible to have both the matrix and reinforcement phases of nanometer dimensions. The improvement in mechanical properties of MMNCs is attributed to the size and strength of the reinforcement as well as to the fine grain size of the matrix. Spark plasma sintering has been used extensively over the past years to consolidate wide range of materials including nanocomposites and was shown to be effective noneconventional sintering method for obtaining fully dense materials with preserved nanostructure features. The objective of this work is to briefly present the spark plasma sintering process and review published work on spark-plasma-sintered metals and metal matrix nanocomposites.

Robust design of multimachine power system stabilizers using simulated annealing

Abstract: Robust design of multimachine power system stabilizers (PSSs) using simulated annealing (SA) optimization technique is presented in this paper. The proposed approach employs SA to search for optimal parameter settings of a widely used conventional fixed-structure lead-lag PSS (CPSS). The parameters of the proposed simulated annealing based power system stabilizer (SAPSS) are optimized in order to shift the system electromechanical modes at different loading conditions and system configurations simultaneously to the left in the s-plane. Incorporation of SA as a derivative-free optimization technique in PSS design significantly reduces the computational burden. One of the main advantages of the proposed approach is its robustness to the initial parameter settings. In addition, the quality of the optimal solution does not rely on the initial guess. The performance of the proposed SAPSS under different disturbances and loading conditions is investigated for two multimachine power systems. The eigenvalue analysis and the nonlinear simulation results show the effectiveness of the proposed SAPSS's to damp out the local as well as the interarea modes and enhance greatly the system stability over a wide range of loading conditions and system configurations.

Solutions of the nonrelativistic wave equation with position-dependent effective mass

Abstract: Given a spatially dependent mass distribution, we obtain potential functions for exactly solvable nonrelativistic problems. The energy spectrum of the bound states and their wave functions are written down explicitly. This is accomplished by mapping the wave equation for these systems into well-known exactly solvable Schrodinger equations with constant mass using point canonical transformation. The Oscillator, Coulomb, and Morse class of potentials are considered.