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Ferrocenylethynyl - A Versatile Platform For New Molecules To Novel Materials, Hakikulla H. Shah, Rayya A. Al-Belushi, Muhammad S. Khan Apr 2025

Ferrocenylethynyl - A Versatile Platform For New Molecules To Novel Materials, Hakikulla H. Shah, Rayya A. Al-Belushi, Muhammad S. Khan

Sultan Qaboos University Journal For Science

Ferrocenylethynyl is a key starting material for the synthesis of fascinating new molecules and novel functional materials. It combines the robust and redox-active ferrocene moiety with the rigid-rod ethynyl unit. The ferrocene center provides chemically and electrochemically switchable material properties whereas the ethynyl backbone facilitates electron delocalization along the molecule, yielding materials with the potential for a wide range of applications from sensors to bio-organometallics and pharmaceuticals, from catalysts to nonlinear optical materials, and from fuel additives to chelating agents. However, lifetime performances and costs still need to be optimized to make ferrocenylethynyl-based materials commercially competitive. Efficient synthetic methods are …

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Late Cretaceous Sub-Marine Fan System In Batain Mélange Zone, The Fayah Formation In Northeastern Oman, Iftikhar Ahmed Abbasi, Abdulrahman Al-Harthy, Yahya Khalifa Al-Subhi Apr 2025

Late Cretaceous Sub-Marine Fan System In Batain Mélange Zone, The Fayah Formation In Northeastern Oman, Iftikhar Ahmed Abbasi, Abdulrahman Al-Harthy, Yahya Khalifa Al-Subhi

Sultan Qaboos University Journal For Science

The Batain coast along the northeastern margin of Oman between Ra’s Al-Hadd and Ra’s Jibsch, is comprised of Permian to Late Cretaceous complex stratigraphy in a tectonically deformed area recording Permian rifting to late Cretaceous Tethys closure events. These rocks are thrust over Mesozoic and older autochthonous sedimentary cover in the form of a major nappe structure known as the Batain Nappe. The uppermost part of the Batain nappe is comprised of isolated outcrops of early Maastrichtian siliciclastic Fayah Formation dominated by gravity flow deposits. The Fayah Formation in the Jabal Fayah area is over four hundred meters thick and …

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Velocity Profiles For Flow Of Omani Crude Oils And Other Liquids, Sayyadul Arafin, S. M. Mujibur Rahman Apr 2025

Velocity Profiles For Flow Of Omani Crude Oils And Other Liquids, Sayyadul Arafin, S. M. Mujibur Rahman

Sultan Qaboos University Journal For Science

Velocity profiles of Newtonian immiscible liquids undergoing laminar flow between two horizontal plates under pressure gradient are investigated using a momentum balance equation. The differential equation describing the flow has been solved and equations for the velocity profiles of a two-layer and three-layer liquid systems are presented. As examples, we show flow patterns of two-layer water-crude oil system and three-layer system involving water, tetrachloromethane, xylene, cyclopentane and hexane. A distinctive pattern is noticeable between the velocity profiles of heavy (API 19.19) and light (API 40.89) Omani crude oils.

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Fcc, Bcc And Sc Lattices Derived From The Coxeter-Weyl Groups And Quaternions, Nazife Özdeş Koca, Mehmet Koca, Muna Al-Sawafi Apr 2025

Fcc, Bcc And Sc Lattices Derived From The Coxeter-Weyl Groups And Quaternions, Nazife Özdeş Koca, Mehmet Koca, Muna Al-Sawafi

Sultan Qaboos University Journal For Science

We construct the fcc (face centered cubic), bcc (body centered cubic) and sc (simple cubic) lattices as the root and the weight lattices of the affine extended Coxeter groups W(A3) and W(B3)=Aut(A3). It is naturally expected that these rank-3 Coxeter-Weyl groups define the point tetrahedral symmetry and the octahedral symmetry of the cubic lattices which have extensive applications in material science. The imaginary quaternionic units are used to represent the root systems of the rank-3 Coxeter-Dynkin diagrams which correspond to the generating vectors of the lattices of interest. The group elements are written explicitly in terms of pairs of quaternions …

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An Annotated Checklist Of The Mammals Of Kuwait, Peter J. Cowan Apr 2025

An Annotated Checklist Of The Mammals Of Kuwait, Peter J. Cowan

Sultan Qaboos University Journal For Science

An annotated checklist of the mammals of Kuwait is presented, based on the literature, personal communications, a Kuwait website and a blog and the author’s observations. Twenty five species occur, a further four are uncommon or rare visitors, six used to occur whilst another two are of doubtful provenance. This list should assist those planning desert rehabilitation, animal reintroduction and protected area projects in Kuwait.

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Synthesis Of Highly Ordered Crystalline Wurtzite (Zno) Membrane For Selenium-Chromium Separation, Sh. Labib, N.A. Tadros Apr 2025

Synthesis Of Highly Ordered Crystalline Wurtzite (Zno) Membrane For Selenium-Chromium Separation, Sh. Labib, N.A. Tadros

Sultan Qaboos University Journal For Science

Pure ZnO and composite ZnO-CeO2 coated thin films on titania substrates were prepared using a chelating sol-gel method under controlled conditions to be used in the separation and/or rejection of Se(IV) and Cr(VI). XRD and SEM studies confirmed the formation of highly ordered arrays of crystalline wurtzite microstructure with mixed orientation. An increase in average particle size of the prepared membranes from 1.25 to 3 µm with increasing CeO2 percent was observed indicating the vital role of CeO2 as secondary phase in improving the crystallinity of the coated films formed. Detailed study of the separation performance of the selected membranes …

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Chiral Polyhedra Derived From Coxeter Diagrams And Quaternions, Mehmet Koca, Nazife Ozdes Koca, Muna Al-Shueili Apr 2025

Chiral Polyhedra Derived From Coxeter Diagrams And Quaternions, Mehmet Koca, Nazife Ozdes Koca, Muna Al-Shueili

Sultan Qaboos University Journal For Science

There are two chiral Archimedean polyhedra, the snub cube and snub dodecahedron together with their dual Catalan solids, pentagonal icositetrahedron and pentagonal hexacontahedron. In this paper we construct the chiral polyhedra and their dual solids in a systematic way. We use the proper rotational subgroups of the Coxeter groups and to derive the orbits representing the solids of interest. They lead to the polyhedra tetrahedron, icosahedron, snub cube, and snub dodecahedron respectively. We prove that the tetrahedron and icosahedron can be transformed to their mirror images by the proper rotational octahedral group so they are not classified in the class …

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An Approach To Analyze The Ambiguity In Rna Structure, Shailendra Singh, Amardeep Singh Apr 2025

An Approach To Analyze The Ambiguity In Rna Structure, Shailendra Singh, Amardeep Singh

Sultan Qaboos University Journal For Science

DNA and RNA are two very important bio-molecules of the human cell. RNA is the second major form of nucleic acid in human cells that plays an intermediary role between DNA and functional protein. Several classes of RNA’s are found in cells, each with a / its distinct function. Understanding of storage and utilization of a cell’s genetic information is based on the structure of RNA. However, Many many experimental results have shown that RNA plays a another greater role in the cells. RNA sequences contains which contain signals at the structure level can be exploited to detect functional motifs …

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Lithofacies Attributes Of A Transgressive Carbonate System : The Middle Eocence Seeb Formation, Al Khoud Area, Muscat, Oman, Osman Salad Hersi, Abdulrahman Al-Harthy Apr 2025

Lithofacies Attributes Of A Transgressive Carbonate System : The Middle Eocence Seeb Formation, Al Khoud Area, Muscat, Oman, Osman Salad Hersi, Abdulrahman Al-Harthy

Sultan Qaboos University Journal For Science

The Seeb Formation (Middle Eocene) is an about 600 m thick transgressive carbonate succession deposited in the Batina and Muscat coastal region of Oman. The formation consists of five informal, but distinct units, and their stacking architecture suggests a deepening-upward, shallow marine depositional setting. Unit I is characterized by cross-bedded, sandy, bioclastic packstones to grainstones deposited in a high energy beach-to-intertidal environment. Unit II consists of indistinctly bedded, nodular, bioclastic (mainly larger foraminifera) packstones and wackestones deposited in a logoonal lagoonal environment. Unit III is defined by medium to thickly bedded, bioclastic packestones to grainstones and subordinate, laterally confined conglomerates. …

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An Electrophoretic Study Of Ldh-Isozyme Distribution In Developing Embryonic And Adult Tissues Of The Toad Bufo Arabicus, Intisar Ambusaidi, Taher Ba-Omar, Saif Al-Bahri, Aisha Al-Shihi Apr 2025

An Electrophoretic Study Of Ldh-Isozyme Distribution In Developing Embryonic And Adult Tissues Of The Toad Bufo Arabicus, Intisar Ambusaidi, Taher Ba-Omar, Saif Al-Bahri, Aisha Al-Shihi

Sultan Qaboos University Journal For Science

Lactate (LDH) dehydrogenases were studied by electrophoresis to investigate the possibility of isozymic differences in different stages and organs of B. arabicus embryos, tadpoles and adults. The expression pattern of lactate dehydrogenase (LDH) isozymes was analysed using nondenaturing discontinuous polyacrylamide gel electrophoresis (PAGE). Five LDH isozymes were observed in five different adult tissues. The most cathodal isozyme LDH-5 (A4) showed the strongest activity. All embryonic stages tested displayed the anodic isozymes first. Four LDH isozymes were present in the stages 1-16 (fertilized egg-tail bud stage). The first appearance of the fifth isozyme was detected in stage 17 when the muscular …

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Pcr Based Detection Of Genetically Modified Soy In Processed Foods Commercially Available In Saudi Arabia, Ibrahim Abdullah Alaraidh Apr 2025

Pcr Based Detection Of Genetically Modified Soy In Processed Foods Commercially Available In Saudi Arabia, Ibrahim Abdullah Alaraidh

Sultan Qaboos University Journal For Science

In this research, PCR (polymerase chain reaction) technique was applied to detect the presence of GMO sold in the Saudi Arabian market. This method was applied to detect genetically modified soy (GM-soy) in particular the roundup ready soy (RRS). To confirm the presence of soy, samples were first tested for the existence of the soy specific lectin gene. A total of eighty samples were tested out of which two samples tested positive as GM-soy. Not surprisingly, the findings showed the existence of GM-soy in food products in Saudi. This supports the necessity of developing precise quantitative and qualitative ways for …

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Studies Of Surface Area And Pore Structure On Portland Cement Produced In Bajil And Amran, Yemen, A.M. Saad, Abdul-Basit A. Saleh, Fatima A. Al-Kadri, Abdulla S. Babaqi, Abdulla A. Basissa, S.A. Abo El-Enein Apr 2025

Studies Of Surface Area And Pore Structure On Portland Cement Produced In Bajil And Amran, Yemen, A.M. Saad, Abdul-Basit A. Saleh, Fatima A. Al-Kadri, Abdulla S. Babaqi, Abdulla A. Basissa, S.A. Abo El-Enein

Sultan Qaboos University Journal For Science

Portland cement pastes of various porosities were prepared using water/cement ratios of 0.30, 0.35, 0.40, 0.45, 0.50 and 0.55; and were hydrated for various time intervals ranging from 0.021 to 28 days. Pore structure and VL–t plots (plots of volume vs. thickness) of the hardened cement pastes were measured using nitrogen gas as the adsorbate. The results were found to be related to the mechanism of hydration as controlled by the pore system of the hardened pastes. Type ІІ adsorption isotherms of nitrogen were obtained for all hardened cement pastes. The adsorption-desorption isotherms indicated the existence of closed hysteresis loops …

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Simulation Of Decadal Precipitation Over Nairobi In Kenya, John Muthama Nzioka, Manene M. Moses, Ndetei Cornelius Joseph Apr 2025

Simulation Of Decadal Precipitation Over Nairobi In Kenya, John Muthama Nzioka, Manene M. Moses, Ndetei Cornelius Joseph

Sultan Qaboos University Journal For Science

In investigating Kenya rainfall variability and its relationship to other climatic elements it has become imperative to analyze the irregularly distributed rainfall events in time. To meet this requirement, this study used a stepwise regression technique. The study seeks to improve existing rainfall monitoring and prediction in Nairobi. Monthly rainfall data was fitted to several mathematical functions. The best mathematical model which best simulated the March-May (MAM) and October -December (OND) seasonal rainfall over the three stations of analysis was chosen using a stepwise regression technique. The value of R-squared for the best fit was computed to show the percentage …

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Application Of Neural Networks To Data Mining, Zlatinka Svetoslavova Kovacheva Apr 2025

Application Of Neural Networks To Data Mining, Zlatinka Svetoslavova Kovacheva

Sultan Qaboos University Journal For Science

Data Mining accomplishes nontrivial extraction of implicit, previously unknown, and potentially useful information of data. The aim of data mining is to discover knowledge out of data and present it in a form that is easily comprehensible to humans. Neural Networks are analytic techniques capable of predicting new observations from other observations after executing a process of so-called learning from existing data. Neural Network techniques can also be used as a component of analyses designed to build explanatory models. Now there is neural network software that uses sophisticated algorithms directly contributing to the model building process. The latest developments in …

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A Knowledge-Induced Operator Model, M.A. Choudhury, S.I. Zaman, Yaqoub Al-Nassar Apr 2025

A Knowledge-Induced Operator Model, M.A. Choudhury, S.I. Zaman, Yaqoub Al-Nassar

Sultan Qaboos University Journal For Science

Learning systems are in the forefront of analytical investigation in the sciences. In the social sciences they occupy the study of complexity and strongly interactive world-systems. Sometimes they are diversely referred to as symbiotics and semiotics when studied in conjunction with logical expressions. In the mathematical sciences the methodology underlying learning systems with complex behavior is based on formal logic or systems analysis. In this paper relationally learning systems are shown to transcend the space-time domain of scientific investigation into the knowledge dimension. Such a knowledge domain is explained by pervasive interaction leading to integration and followed by continuous evolution …

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Harmful Algal Blooms: Physiology, Behavior, Population Dynamics And Global Impacts- A Review, H.M. Al-Ghelani, A.Y.A Alkindi, S. Amer, Y.K Al-Akhzami Apr 2025

Harmful Algal Blooms: Physiology, Behavior, Population Dynamics And Global Impacts- A Review, H.M. Al-Ghelani, A.Y.A Alkindi, S. Amer, Y.K Al-Akhzami

Sultan Qaboos University Journal For Science

Harmful, toxic algae are now considered as one of the important players in the newly emerging environmental risk factors. The apparent global increase in harmful algal blooms (HABs) is becoming a serious problem in both aquaculture and fisheries populations. Not only has the magnitude and intensity of public health and economic impacts of these blooms increased in recent years, but the number of geographic locations experiencing toxic algal blooms has also increased dramatically. There are two primary factors causing HABs outbreaks. The natural processes such as upwelling and relaxation, and the anthropogenic loading resulting in eutrophication. However, the influence of …

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Xanthotoxin And Other Furanocoumarins As Phytoalexins In Pastinaca Sativa L. Roots, Fatma M. Al-Barwani, Elsadig A. Eltayeb Apr 2025

Xanthotoxin And Other Furanocoumarins As Phytoalexins In Pastinaca Sativa L. Roots, Fatma M. Al-Barwani, Elsadig A. Eltayeb

Sultan Qaboos University Journal For Science

Our results confirm the presence of the furanocoumarins psoralen, xanthotoxin, isopimpinellin, angelicin and bergapten as normal constituents of Pastinaca sativa roots. However, the amounts of these compounds were increased in induced roots. The amount of increase in the induced roots varied depending on the inducing agent and time of incubation. In addition the results show for the first time the presence of pimpinellin and isobergapten as constitutive antifungal compounds in P. sativa roots.

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Synchronization And Oscillator Death In Diffusively Coupled Lattice Oscillators, Adu A.M. Wasike Apr 2025

Synchronization And Oscillator Death In Diffusively Coupled Lattice Oscillators, Adu A.M. Wasike

Sultan Qaboos University Journal For Science

We consider the synchronization and cessation of oscillation of a positive even number of planar oscillators that are coupled to their nearest neighbours on one, two, and three dimensional integer lattices via a linear and symmetric diffusion-like path. Each oscillator has a unique periodic solution that is attracting. We show that for certain coupling strength there are both symmetric and antisymmetric synchronization that corresponds to symmetric and antisymmetric non-constant periodic solutions respectively. Symmetric synchronization persists for all coupling strengths while the antisymmetric case exists for only weak coupling strength and disappears to the origin after a certain coupling strength.

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Intelligent Techniques For Power Systems Vulnerability Assessment, Mohamed A. El-Sharkawi Apr 2025

Intelligent Techniques For Power Systems Vulnerability Assessment, Mohamed A. El-Sharkawi

Sultan Qaboos University Journal For Science

With power grids considered national security matters, the reliable operation of the system is of top priority to utilities. This concern is amplified by the utility’s deregulation, which increases the system’s openness while simultaneously decreasing the applied degree of control. Vulnerability Assessment (VA) deals with the power system’s ability to continue to provide service in case of an unforeseen catastrophic contingency. Such contingencies may include unauthorized tripping, breaks in communication links, sabotage or intrusion by external agents, human errors, natural calamities and faults. These contingencies could lead to a disruption of service to part or all of the system. The …

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Neural-Network-Based Fuzzy Logic Navigation Control For Intelligent Vehicles, Ahcene Farah, Amine Chohra Apr 2025

Neural-Network-Based Fuzzy Logic Navigation Control For Intelligent Vehicles, Ahcene Farah, Amine Chohra

Sultan Qaboos University Journal For Science

This paper proposes a Neural-Network-Based Fuzzy logic system for navigation control of intelligent vehicles. First, the use of Neural Networks and Fuzzy Logic to provide intelligent vehicles with more autonomy and intelligence is discussed. Second, the system for the obstacle avoidance behavior is developed. Fuzzy Logic improves Neural Networks (NN) obstacle avoidance approach by handling imprecision and rule-based approximate reasoning. This system must make the vehicle able, after supervised learning, to achieve two tasks: 1- to make one’s way towards its target by a NN, and 2- to avoid static or dynamic obstacles by a Fuzzy NN capturing the behavior …

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Problems Of Bacteriological Pollution In Water Wells In Wadi Hadramout Water Project, Salem M. Bin Qadhi, Saeed Y. Bashir, Taha O. Assaggaf Apr 2025

Problems Of Bacteriological Pollution In Water Wells In Wadi Hadramout Water Project, Salem M. Bin Qadhi, Saeed Y. Bashir, Taha O. Assaggaf

Sultan Qaboos University Journal For Science

This paper presents an existing problem of drinking water pollution for a small project and one of the model projects of drinking water in Yemen, designed to save and preserve good quality water for the present and future generations in the area. The paper gives the details of the project and explains the problem of bacteriological pollution and the steps undertaken to solve the problem. Some of the results for short-term solutions and recommendation for the long-term solutions are also given.

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Review Of Omani Aflaj Systems: An Element Of National Water Resources,Technology And Economic Developments, Abulbasher M. Shahalam Apr 2025

Review Of Omani Aflaj Systems: An Element Of National Water Resources,Technology And Economic Developments, Abulbasher M. Shahalam

Sultan Qaboos University Journal For Science

The paper includes a comprehensive review of the various aspects: agriculture, soil, water resources and socio-economic concerns associated with the aflaj facilities within the Sultanate of Oman. From available literature, the author identified and presented factors that affect the viability and sustainance of this traditional, existing and unique system of water resources management. The system weakness and strength at the advent of modern technology, life-style and wealth were also identified. Technical data on demography, geography, soil, water, irrigation, crop-pattern and activities of organizations related to aflaj systems were summerized and illustrated in figures and tables.

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Variation In Seedling Characteristics Of Five Populations Of Acacia Tortilis From The United Arab Emirates In Response To Increasing Sodium Chloride Concentrations, Fatma. M. Al-Ansari, Rashied. S. Modawi Apr 2025

Variation In Seedling Characteristics Of Five Populations Of Acacia Tortilis From The United Arab Emirates In Response To Increasing Sodium Chloride Concentrations, Fatma. M. Al-Ansari, Rashied. S. Modawi

Sultan Qaboos University Journal For Science

Seeds of Acacia tortilis collected from 5 sites around the city of Al Ain in the United Arab Emirates were germinated in 4 concentrations of sodium chloride (0, 20, 90 and 150 mM of NaCl). Percent of germination, rate of germination, seedling moisture content, root and shoot lengths and seedling lengths were all significantly affected by salt stress. Seeds collected from the different sites were significantly different in their response to salinity conditions. Variations in the response of seedlings from different sites to the different salt treatments suggest an underlying genetic variability within the A. tortilis populations, possibly resulting from …

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Endocrine, Physiological And Histopathological Responses Of Fish And Their Larvae To Stress With Emphasis On Exposure To Crude Oil And Various Petroleum Hydrocarbons, A. Y. A. Al-Kindi, J.A. Brown, C.P. Waring Apr 2025

Endocrine, Physiological And Histopathological Responses Of Fish And Their Larvae To Stress With Emphasis On Exposure To Crude Oil And Various Petroleum Hydrocarbons, A. Y. A. Al-Kindi, J.A. Brown, C.P. Waring

Sultan Qaboos University Journal For Science

Various endocrine and physiological responses of fish exposed to forceful physical and chemical stimuli are reviewed with emphasis on the effects of crude oils and their hydrocarbon constituents. The chemistry and toxicity of petroleum hydrocarbons are examined and methods for experimental exposure of fish to crude oil and petroleum hydrocarbons are considered. A variety of blood-borne parameters recognized as reliable tools in determining the relative severity of stress in fish are reviewed. The effects of stress and petroleum hydrocarbons on endocrine responses including changes in plasma catecholamines, corticosteroids, and thyroid hormones are reviewed. The physiological responses: changes in plasma glucose, …

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Research Trends : Natural Products As Pest, Microbial Disease An Tumour Control Agents, M.O. Fatope, Salma M. Z. Al-Kindi, Abdulrahman O. Abdulnour Apr 2025

Research Trends : Natural Products As Pest, Microbial Disease An Tumour Control Agents, M.O. Fatope, Salma M. Z. Al-Kindi, Abdulrahman O. Abdulnour

Sultan Qaboos University Journal For Science

The zeal to conquer human, agronomic, and veterinary diseases or pests has always sustained research interests directed at finding new medications from under explored biodiversity. The adoption of bioassay methods, which correlate with prevention, inhibition and reversal of diseases or elimination of pests, in screening natural products for bioactive compounds is critical to the discovery of new medications. This article focuses on areas of natural products chemistry that connect academia with industry. It discusses the technical skills needed to find bioactive compounds from microbes, marine invertebrates, plants and insects, highlighting the mode of action of selected bioactive compounds and bioassay …

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Photovoltaic Cells And Systems: Current State And Future Trends, Hadj Bourdoucen, Joseph A. Jervase, Abdullah Al-Badi, Adel Gastli, Arif Malik Apr 2025

Photovoltaic Cells And Systems: Current State And Future Trends, Hadj Bourdoucen, Joseph A. Jervase, Abdullah Al-Badi, Adel Gastli, Arif Malik

Sultan Qaboos University Journal For Science

Photovoltaics is the process of converting solar energy into electrical energy. Any photovoltaic system invariably consists of solar cell arrays and electric power conditioners. Photovoltaic systems are reliable, quiet, safe and both environmentally benign and self-sustaining. In addition, they are cost-effective for applications in remote areas. This paper presents a review of solar system components and integration, manufacturing, applications, and basic research related to photovoltaics. Photovoltaic applications in Oman are also presented. Finally, the existing and the future trends in technologies and materials used for the fabrication of solar cells are summarized.

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Intelligent Systems For Active Program Diagnosis, Haider Ali Ramadhan, Khalil Shihab Apr 2025

Intelligent Systems For Active Program Diagnosis, Haider Ali Ramadhan, Khalil Shihab

Sultan Qaboos University Journal For Science

Intelligent program diagnosis systems are computer programs capable of analyzing logical and design-level errors and misconceptions in programs. Upon discovering the errors, these systems provide intelligent feedback and thus guide the users in the problem-solving process. Intelligent program diagnosis systems are classified by their primary means of program analysis. The most distinct split is between those systems that are unable to analyze partial code segments as they are provided by the user and must wait until the entire solution code is completed before attempting any diagnosis, and those that are capable of analyzing partial solutions and providing proper guidance whenever …

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Earthquake Response Of A Historical Castle, Mohammed Qamaruddin, Ali Salim Al-Harthy Apr 2025

Earthquake Response Of A Historical Castle, Mohammed Qamaruddin, Ali Salim Al-Harthy

Sultan Qaboos University Journal For Science

The earthquake hazard potential in the Sultanate of Oman is considered real as there are several reports of felt earthquakes in the Sultanate of Oman during the period from years 977 to 1998, although no damage to the existing structures has been reported due to earthquakes. In Oman, seismic zoning map and other basic data are required for the development of a standard code for seismic design of structures. In this paper, seismic response of a historical Nizwa castle in Oman is assessed employing the methodology of Uniform Building Code (UBC, 1994). Also, in the absence of data pertaining to …

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Electromagnetic Modeling Of The Propagation Characteristics Of Satellite Communications Through Composite Precipitation Layers, Part Ii: Results Of Computer Simulations, H.M. Al-Rizzo, H.T. Al-Hafid, J.M. Tranquilla Apr 2025

Electromagnetic Modeling Of The Propagation Characteristics Of Satellite Communications Through Composite Precipitation Layers, Part Ii: Results Of Computer Simulations, H.M. Al-Rizzo, H.T. Al-Hafid, J.M. Tranquilla

Sultan Qaboos University Journal For Science

A versatile Propagation Simulation Program (PSP) is developed to assess the degrading effects caused by the concurrent occurrences of an arbitrary mixture of ice plates and needles, melting snow and raindrops which may impede the reliability of dual-polarized satellite communications systems carrying independent channels on a single radio path. Specifically, results are presented for the Cross Polarization Discrimination (XPD) due to ice and rain, differential attenuation, Da, and differential phase shift, Df, due to rain and average specific attenuation, a, and phase shift, f , due to the melting layer at hitherto unconsidered frequencies. The inclusion of an ice-cloud medium …

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Flow Past A Rotating Circular Cylinder And A Rotlet Using The Finite-Difference Method, T. B. A. El Bashir Apr 2025

Flow Past A Rotating Circular Cylinder And A Rotlet Using The Finite-Difference Method, T. B. A. El Bashir

Sultan Qaboos University Journal For Science

In this paper the flow generated by a rotlet in the presence of a circular cylinder is considered. We introduce a transformation which simplifies the equations and boundary conditions. We use the finite-difference method to obtain results in excellent agreement with all the available analytical results. Results are presented for Reynolds numbers, based on the diameter of the cylinder, in the range 0 ≤ Re ≤ 20 and the rotational parameter, α , in the range 0 ≤α ≤ 3 and strength of rotlet, β , in the range 0 ≤ β ≤ 3 . The results are found to …

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