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.

Heat transfer enhancement of phase change materials for thermal energy storage applications: A critical review

Abstract: This paper presents a state-of-the-art review on various techniques of heat transfer enhancement in latent heat thermal energy storage (LHTES) systems. Heat transfer enhancement in LHTES systems can be achieved through either geometric configuration and/or thermal conductivity enhancement. The use of extended surfaces such as fins or heat pipes is a common technique for heat transfer enhancement in LHTES systems and therefore, reviewed in details in this paper. Next, we studied the thermal conductivity enhancement techniques, which include the use of porous materials, nanoparticles with high thermal conductivity, and low-density materials. Finally, studies involving combined techniques for heat transfer enhancement are reviewed in the paper. The paper discusses research gaps in the methods of heat transfer enhancement for LHTES systems and proposed some recommendations.

ZnO/Ag/Mn2O3 nanocomposite for visible light-induced industrial textile effluent degradation, uric acid and ascorbic acid sensing and antimicrobial activity

Abstract: A facile and inexpensive route has been developed to synthesize a ternary ZnO/Ag/Mn2O3 nanocomposite having nanorod structures based on the thermal decomposition method. The as-synthesized ternary ZnO/Ag/Mn2O3 nanocomposite was characterized and used for visible light-induced photocatalytic, sensing and antimicrobial studies. The ternary ZnO/Ag/Mn2O3 nanocomposite exhibited excellent and enhanced visible light-induced photocatalytic degradation of industrial textile effluent (real sample analysis) compared to pure ZnO. Sensing studies showed that the ternary ZnO/Ag/Mn2O3 nanocomposite exhibited outstanding and improved detection of uric acid (UA) and ascorbic acid (AA). It also showed effective and efficient bactericidal activities against Staphylococcus aureus and Escherichia coli. These results suggest that the small size, high surface area and synergistic effect among ZnO, AgNPs and Mn2O3 induced visible light photocatalytic activity by decreasing the recombination of photogenerated electrons and holes, and extending the response of pure ZnO to visible light, enhanced sensing of UA and AA and antimicrobial activity. Overall, the ternary ZnO/Ag/Mn2O3 nanocomposite is a valuable material that can be used for a range of applications, such as visible light-induced photocatalysis, sensing and antimicrobial activity. Therefore, ternary nanocomposites could have important applications in environmental science, sensing, and biological fields.

Effects of increased solar ultraviolet radiation on materials

Abstract: Synthetic polymers such as plastics, as well as naturally occurring polymer materials such as wood, are extensively used in building construction and other outdoor applications where they are routinely exposed to sunlight. The UV-B content in sunlight is well known to affect adversely the mechanical properties of these materials, limiting their useful life. Presently their outdoor lifetimes depend on the use of photostabilizers in the case of plastics and on protective surface coatings in the case of wood. Any increase in the solar UV-B content due to a partial ozone depletion would therefore tend to decrease the outdoor service life of these materials. It is the synergistic effect of increased UV radiation with other factors such as the temperature that would determine the extent of such reduction in service life. The increased cost associated with such a change would be felt unevenly across the globe. Those developing countries that depend on plastics as a prime material of construction and experience high ambient temperatures are likely to be particularly affected in spite of the relatively small fractional decrease in ozone at those locations. Assessment of the damage to materials, associated with ozone depletion, requires a knowledge of the wavelength dependence as well as the dose-response characteristics of the polymer degradation processes of interest. While the recent literature includes some reliable spectral sensitivity data, little dose-response information has been reported, so it is difficult to make such assessments reliably at the present time. This is particularly true for the naturally occurring materials popularly used in construction applications. To maintain polymers at the same useful lifetime in spite of increased solar UV-B content, the amount of photostabilizers used in the formulations might be increased. This strategy assumes that conventional stabilizers will continue to be effective with the spectrally altered UV-B-enhanced solar radiation. While the present understanding of the degradation chemistry suggests the strategy to have merit, its effectiveness, in an altered solar radiation environment, has not been demonstrated for common polymers. The availability of these data is crucial for reliably estimating the cost of mitigating the increased damage to materials as a result of a possible partial depletion of the ozone layer using this approach.

Review on Surfactant Flooding: Phase Behavior, Retention, IFT, and Field Applications

Abstract: Surfactant flooding is an important technique used in enhanced oil recovery to reduce the amount of oil in pore space of matrix rock. Surfactants are injected to mobilize residual oil by lowering the interfacial tension between oil and water and/or by the wettability alteration from oil-wet to water-wet. A large number of cationic, anionic, non-ionic, and amphoteric surfactants have been investigated on a laboratory scale under different conditions of temperature and salinity. Selection of the appropriate surfactant is a challenging task, and surfactants have to be evaluated by a series of screening techniques. Different types of surfactants along with their limitations are reviewed with particular emphasis on the phase behavior, adsorption, interfacial tension, and structure–property relationship. Factors affecting the phase behavior, interfacial tension, and wettability alteration are also discussed. Field applications of surfactants for chemical enhanced oil recovery in carbonate and sandstone reservoi...

Adsorption Behavior of Glucosamine-Based, Pyrimidine-Fused Heterocycles as Green Corrosion Inhibitors for Mild Steel: Experimental and Theoretical Studies

Abstract: Effects of electron donating (−CH3 and −OH) and electron withdrawing (−NO2) substituents on the corrosion inhibition efficiency of four glucosamine-based, substituted, pyrimidine-fused heterocycles (CARBs) on mild steel corrosion in 1 M HCl have been investigated using gravimetric, electrochemical, surface morphology (SEM, AFM, and EDX), and computational techniques. Gravimetric studies showed that protection performances of the compounds increase with increase in concentration. Both electron withdrawing (−NO2) and electron donating (−CH3 and −OH) groups were found to enhance the inhibition efficiency, but the effect is more pronounced with electron-donating substituents. The compounds were found to be cathodic-type inhibitors as inferred from the results of potentiodynamic polarization studies. EIS studies suggested that the studied compounds inhibit metallic corrosion by adsorbing on metallic surface. The adsorption of the inhibitor molecules on steel surface was further supported by SEM, AFM, and EDX a...