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.

Impact of nanoparticles on human and environment: review of toxicity factors, exposures, control strategies, and future prospects

Abstract: Nanotechnology has revolutionized the world through introduction of a unique class of materials and consumer products in many arenas. It has led to production of innovative materials and devices. Despite of their unique advantages and applications in domestic and industrial sectors, use of materials with dimensions in nanometers has raised the issue of safety for workers, consumers, and human environment. Because of their small size and other unique characteristics, nanoparticles have ability to harm human and wildlife by interacting through various mechanisms. We have reviewed the characteristics of nanoparticles which form the basis of their toxicity. This paper also reviews possible routes of exposure of nanoparticles to human body. Dermal contact, inhalation, and ingestion have been discussed in detail. As very limited data is available for long-term human exposures, there is a pressing need to develop the methods which can determine short and long-term effects of nanoparticles on human and environment. We also discuss in brief the strategies which can help to control human exposures to toxic nanoparticles. We have outlined the current status of toxicological studies dealing with nanoparticles, accomplishments, weaknesses, and future challenges.

Simultaneous stabilization of multimachine power systems via genetic algorithms

Abstract: This paper demonstrates the use of genetic algorithms for the simultaneous stabilization of multimachine power systems over a wide range of operating conditions via single-setting power system stabilizers. The power system operating at various conditions is treated as a finite set of plants. The problem of selecting the parameters of power system stabilizers which simultaneously stabilize this set of plants is converted to a simple optimization problem which is solved by a genetic algorithm with an eigenvalue-based objective function. Two objective functions are presented, allowing the selection of the stabilizer parameters to shift some of the closed-loop eigenvalues to the left-hand side of a vertical line in the complex s-plane, or to a wedge-shape sector in the complex s-plane. The effectiveness of the suggested technique in damping local and inter-area modes of oscillations in multimachine power systems is verified through eigenvalue analysis and simulation results.

Integrating genetic algorithms, tabu search, and simulated annealing for the unit commitment problem

Abstract: This paper presents a new algorithm based on integrating genetic algorithms, tabu search and simulated annealing methods to solve the unit commitment problem. The core of the proposed algorithm is based on genetic algorithms. Tabu search is used to generate new population members in the reproduction phase of the genetic algorithm. A simulated annealing method is used to accelerate the convergence of the genetic algorithm by applying the simulated annealing test for all the population members. A new implementation of the genetic algorithm is introduced. The genetic algorithm solution is coded as a mix between binary and decimal representation. The fitness function is constructed from the total operating cost of the generating units without penalty terms. In the tabu search part of the proposed algorithm, a simple short-term memory procedure is used to counter the danger of entrapment at a local optimum, and the premature convergence of the genetic algorithm. A simple cooling schedule has been implemented to apply the simulated annealing test in the algorithm. Numerical results showed the superiority of the solutions obtained compared to genetic algorithms, tabu search and simulated annealing methods, and to two exact algorithms.

Progress and latest developments of evacuated tube solar collectors

Abstract: Solar energy is the most available, environmental friendly energy source and renewable to sustain the growing energy demand. Solar energy is captured by solar collectors and an evacuated solar collector is the most efficient and convenient collector among various kinds of solar collectors. In this paper, a comprehensive literature on why evacuated collector is preferable, types of evacuated collectors, their structure, applications and challenges have been reviewed. Latest up to date literature based on journal articles, web materials, reports, conference proceedings and thesis have been compiled and reported. Applications of evacuated solar collectors in water heating, heat engines, air conditioning, swimming pool heating, solar cooker, steam generation and solar drying for residential and industrial sectors have been summarized and presented. Collector efficiency of different types of evacuated collectors and their performance based on different working fluids have been reported as well. Based on the available literature, it has been found that an evacuated tube collector has higher efficiency than the other collector. An evacuated tube collector is also very efficient to be used at higher operating temperature. There are few challenges that have been identified and need to be addressed carefully before installing an evacuated tube solar collector. However, after critically analyzing the available literature, authors have presented some future recommendations to overcome the barriers and for enhanced performance of an evacuated tube solar collector.