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.

Repeat Purchase Intentions in Online Shopping: The Role of Satisfaction, Attitude, and Online Retailers' Performance

Abstract: A model of determinants of repeat purchase intentions of consumers who have previously bought online is developed and empirically tested. Data for the model test comes from responses to a structured self-administered survey provided by a sample of 436 consumers in Saudi Arabia. The results confirm hypothesized positive effects of overall satisfaction with previous online purchases and attitude toward online purchasing on repeat purchase intentions. In turn, attitude is positively determined by overall satisfaction and negatively by experience with online purchase problems, while overall satisfaction is determined positively by satisfaction with the following online retailers' performance dimensions: product prices, product quality, customer service, required payment methods, perceived payment security, and delivery time. Contrary to expectations, delivery cost is not significantly related to overall satisfaction. Neither does experience with online purchase problems. Theoretical and marketing str...

A Miniaturized UWB Biplanar Yagi-Like MIMO Antenna System

Abstract: A novel 2-element ultrawideband Yagi-based multiple-input-multiple-output (MIMO) antenna system is presented based on loop excitation. Half of the driven loop element is implemented on each side of the substrate, which not only reduces the overall size of the antenna by 45%, but also increases its bandwidth significantly. The center frequency of operation is 5.8 GHz targeting WLAN applications. The proposed design has a wide measured bandwidth of 2.401 GHz covering 4.183-6.584 GHz. The proposed compact MIMO antenna system has an overall size of 50 × 80 × 0.76 mm 3 with a single element size of 50 × 40 × 0.76 mm 3 . The proposed Yagi antenna has high directional radiation characteristics with a minimum measured front-to-back ratio of 18 dB, minimum measured gain of 6 dBi, and directivity of 6.6 dB using a single director element only, at 5.8 GHz. It has a minimum measured isolation of 17 dB, measured maximum envelope correlation coefficient value of 0.0568, and measured total efficiency above 80% across the band of operation.

Effectiveness of corrosion inhibitors in contaminated concrete

Abstract: Four types of corrosion inhibitors (calcium nitrite at two dosages, calcium nitrate at three dosages and two organic inhibitors at their recommended dosages) were evaluated at five different levels of contamination, i.e., 0.8% chloride; 0.8% chloride plus 1.5% SO3; seawater; brackish water; and unwashed aggregates. Concrete specimens were used to assess the effect of corrosion inhibitors on the compressive strength of concrete and reinforcement corrosion. The results indicated that the corrosion inhibitors investigated in this study did not adversely affect the compressive strength of concrete. Furthermore, calcium nitrite was efficient in delaying the initiation of reinforcement corrosion in the concrete specimens contaminated with chloride, while both calcium nitrite and calcium nitrate mitigated the corrosive effects of chloride plus sulfate salts or sea water. In the concrete specimens prepared with brackish water or unwashed aggregates, all the inhibitors were effective in reducing the rate of reinforcement corrosion. The type and dosage of corrosion inhibitor were observed to be dependent on the nature and level of contamination.