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.

Robust tuning of power system stabilizers in multimachine power systems

Abstract: Summary form only given as follows. This paper demonstrates the robust tuning of power systems stabilizers for power systems, operating at different loading conditions. A classical lead-lag power system stabilizer is used to demonstrate the technique. The problem of selecting the stabilizer parameters is converted to a simple optimization problem with an eigenvalue-based objective function, which is solved by a tabu search algorithm. The objective function allows the selection of the stabilizer parameters to optimally place the closed-loop eigenvalues in the left-hand side of a vertical line in the complex s-plane. The effectiveness of the stabilizers tuned using the suggested technique, in enhancing the stability of power systems, is confirmed through eigenvalue analysis and simulation results.

Application of various water soluble polymers in gas hydrate inhibition

Abstract: Formation of hydrates in gas transmission lines due to high pressures and low temperatures is a serious problem in the oil and gas industry with potential hazards and/or economic losses. Kinetic hydrate inhibitors are water soluble polymeric compounds that prevent or delay hydrate formation. This review presents the various types of water soluble polymers used for hydrate inhibition, including conventional and novel polymeric inhibitors along with their limitations. The review covers the relevant properties of vinyl lactam, amide, dendrimeric, fluorinated, and natural biodegradable polymers. The factors affecting the performance of these polymers and the structure–property relationships are reviewed. A comprehensive review of the techniques used to evaluate the performance of the polymeric inhibitors is given. This review also addresses recent developments, current and future challenges, and field applications of a range of polymeric kinetic hydrate inhibitors.

Recent progress in perovskite solar cells

Abstract: Perovskite hybrid solar cells are in vogue in solar cell research. Dye-sensitized solar (DSS) cells, thin film solar cell and silicon solar cell, among others, owing to their efficiencies that are comparable to crystalline Si solar cells and ease of fabrication by a low-temperature solution technique. Although perovskite solar cells have been accounted for to exhibit enhanced output of about 21% from about 9.7%, limited researches have been conducted to find out their low stability that impedes outdoor applications. The issue of degradation of perovskite and the stability of perovskite solar cells should be addressed for good reproducibility and long life time with high conversion efficiencies. The present review aims to represent an account of the advancement in the organic, inorganic perovskite solar cells and the extent of fabrication techniques with a view to understand the material efficiency relationships.

Systematic literature review and empirical investigation of barriers to process improvement in global software development

Abstract: ContextIncreasingly, software development organizations are adopting global software development (GSD) strategies, mainly because of the significant return on investment they produce. However, there are many challenges associated with GSD, particularly with regards to software process improvement (SPI). SPI can play a significant role in the successful execution of GSD projects. ObjectiveThe aim of the present study was to identify barriers that can negatively affect SPI initiatives in GSD organizations from both client and vendor perspectives. MethodA systematic literature review (SLR) and survey questionnaire were used to identify and validate the barriers. ResultsTwenty-two barriers to successful SPI programs were identified. Results illustrate that the barriers identified using SLR and survey approaches have more similarities However, there were significant differences between the ranking of these barriers in the SLR and survey approaches, as indicated by the results of t-tests (for instance, t=2.28, p=0.011<0.05). Our findings demonstrate that there is a moderate positive correlation between the ranks obtained from the SLR and the empirical study (rs (22)=0.567, p=0.006). ConclusionsThe identified barriers can assist both client and vendor GSD organizations during initiation of an SPI program. Client-vendor classification was used to provide a broad picture of SPI programs, and their respective barriers. The top-ranked barriers can be used as a guide for GSD organizations prior to the initiation of an SPI program. We believe that the results of this study can be useful in tackling the problems associated with the implementation of SPI, which is vital to the success and progression of GSD organizations.