Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 208321 - 208350 of 5207136

Full-Text Articles in Entire DC Network

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 …

Go to article

An Assessment Of Solid Waste And Landfilis In Muscat Area, Oman, Alaa El-Zawahry, Abulbasher M. Shahalam, Ramzi Taha, Turki Al-Busaidi Apr 2025

An Assessment Of Solid Waste And Landfilis In Muscat Area, Oman, Alaa El-Zawahry, Abulbasher M. Shahalam, Ramzi Taha, Turki Al-Busaidi

Sultan Qaboos University Journal For Science

The paper presents the results of a 1998 study of the solid waste generation within the greater Muscat City area. The recent data were compared with the available data from the last 10 years to assess the solid waste problems within the area. Five operating landfills were used as the data collection points. It appeared that through the last decade, the solid waste generation rate has increased sharply. However, the rate of waste production stabilized to 750 – 800 ton/day during the last three years of the 1990s. The rate amounts to 1.5 kg/person/day. Overall municipal waste volume decreased through …

Go to article

Selection Of Liner Materials And Design Of Hazardous Water Facilities In Saudi Arabia, Sahel N. Abduljauwad, Ali M. Dakkak Apr 2025

Selection Of Liner Materials And Design Of Hazardous Water Facilities In Saudi Arabia, Sahel N. Abduljauwad, Ali M. Dakkak

Sultan Qaboos University Journal For Science

Rapid development in Saudi Arabia has produced a broad spectrum of wastes. In the last two decades, several refineries and petrochemical industries have been established. These industries have produced sludges and other toxic wastes which need proper planning for their handling and disposal. This paper covers design and selection of liner materials for two hazardous waste disposal sites. One of them is located in the Eastern Province of Saudi Arabia, while the second one is located in the Western part. The paper will present complete design details of the natural compacted and geosynthetic soil liners and the leachate collection and …

Go to article

Effect Of Ph On The Removal Of Chromium (Cr) (Vi) By Sugar Cane Bagasse, Nasim Ahmed Khan, Syed Iqbal Ali, Sohail Ayub Apr 2025

Effect Of Ph On The Removal Of Chromium (Cr) (Vi) By Sugar Cane Bagasse, Nasim Ahmed Khan, Syed Iqbal Ali, Sohail Ayub

Sultan Qaboos University Journal For Science

The industrial estates in India are dominated by small and medium scale industries, which are posing a serious threat to the environment by virtue of discharging effluents of a polluting nature. The problems become severe due to the presence of heavy metals in the effluents. Chromium is widely used in a number of industries such as electroplating, metal finishing, cooling towers, dyes, paints, anodising and leather tanning industries. The toxicity of chromium (VI) is well known and is considered a hazard to the health of humans and animals. The presence of chromium (VI) in aquatic environments at high concentrations is …

Go to article

Tailings From Mining Activities, Impact On Groundwater, And Remediation, Khalid Al-Rawahy Apr 2025

Tailings From Mining Activities, Impact On Groundwater, And Remediation, Khalid Al-Rawahy

Sultan Qaboos University Journal For Science

Effluent wastes from mining operations and beneficiation processes are comprized mostly of the following pollutants: total suspended solids (TTS), alkalinity or acidity (pH), settleable solids, iron in ferrous mining, and dissolved metals in nonferrous mining. Suspended solids consist of small particles of solid pollutants that resist separation by conventional means. A number of dissolved metals are considered toxic pollutants. The major metal pollutants present in ore mining and beneficiation waste waters include arsenic, cadmium, copper, lead, mercury, nickel, and zinc. Tailings ponds are used for both the disposal of solid waste and the treatment of waste-water streams. The supernatant decanted …

Go to article

The Development Of A Database Management In Gis Applications In Oman, Osman Abdallah Osman Akif Apr 2025

The Development Of A Database Management In Gis Applications In Oman, Osman Abdallah Osman Akif

Sultan Qaboos University Journal For Science

The development of applying database management applications is currently underway within Geographical Information Systems (GIS) applications in the Sultanate of Oman.The establishment of a national database management system in Oman is considered as the backbone that is required within the Geographic Information System project in Oman. The principal of the GIS project in Oman was built upon unifying the used software packages over the sultanate which is ARC/INFO as GIS Package and ORACLE as database management software. These packages are used within the different participating Ministries in the GIS project in Oman.The participating ministries will handle information that are shared …

Go to article

Use Of Isotope And Solute Chemistry To Define The Sources Of Pollution In Mawqaq Groundwater, Hail, Saudi Arabia, Ibrahim Abdulaziz Al-Sagaby, Mohamed Ali Moallim Apr 2025

Use Of Isotope And Solute Chemistry To Define The Sources Of Pollution In Mawqaq Groundwater, Hail, Saudi Arabia, Ibrahim Abdulaziz Al-Sagaby, Mohamed Ali Moallim

Sultan Qaboos University Journal For Science

Groundwater in the area is used for different purposes like domestic, agricultural, industrial and landscaping. More than sixty groundwater samples were collected in an alluvial shallow aquifer in and around Mawqaq Town. The objective was to study groundwater quality and identify the sources of Nitrate (NO3) and bacteriological pollution in groundwater using environmental isotopes (2H, 3H and 18O). The results of the study have revealed the presence of average salinity concentration higher than the permissible limits (500 mg/l) for drinking water. Three groups of water saline boundaries were identified. The presence of high nitrate as nitrogen (NO3-N) was also encountered …

Go to article

A Finite Volume Runge-Kutta Ellam Method For The Solution Of Advection Diffusion Equations, Mohammed Al-Lawatia, Robert C. Sharpley, Hong Wang Apr 2025

A Finite Volume Runge-Kutta Ellam Method For The Solution Of Advection Diffusion Equations, Mohammed Al-Lawatia, Robert C. Sharpley, Hong Wang

Sultan Qaboos University Journal For Science

We develop a finite volume characteristic method for the solution of the advection-diffusion equations which model the contaminant transport through porous medium. This method uses a second order Runge-Kutta approximation for the characteristics within the framework of the Eulerian Lagrangian localized adjoint methods (ELLAM). The derived scheme conserves mass, symmetrizes the governing equations and generates accurate numerical solutions even if large time steps are used. Numerical experiments comparing several competitive methods using a standard test example are presented to illustrate the performance of the method.

Go to article

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.

Go to article

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.

Go to article

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 …

Go to article

Desert Nitrogen Cycles: Fecal Nitrogen From A Population Of The Sahelian Tree Locust In Oman, Michael D. Robinson Apr 2025

Desert Nitrogen Cycles: Fecal Nitrogen From A Population Of The Sahelian Tree Locust In Oman, Michael D. Robinson

Sultan Qaboos University Journal For Science

This research quantifies the amount of nitrogen deposited by the tree locust, Anacridium melanorhodon, during an irregular population outbreak in an Acacia tortilis woodland in Oman. The average standing crop of feces was 65.28g m-2. The mean fecal crude protein and nitrogen were respectively, 20.14 and 3.22 g/100 gash-free dry weight. A hectare of this woodland would contain approximately 1.1 kg of fecal nitrogen beneath the trees. This single contribution by the locusts equals about one-third of the total standing crop of detrital nitrogen under perennial vegetation in a hectare of the Mohave Desert of North America. This, and the …

Go to article

Plasma Analysis In Normal Green Sea Turtles, Chelonia Mydas, During Two Different Periods Of Nesting At Ras Al- Hadd, Sultanate Of Oman, Abdulaziz.Y.A. Alkindi, Ibrahim.Y. Mahmoud, Humaid Khan Apr 2025

Plasma Analysis In Normal Green Sea Turtles, Chelonia Mydas, During Two Different Periods Of Nesting At Ras Al- Hadd, Sultanate Of Oman, Abdulaziz.Y.A. Alkindi, Ibrahim.Y. Mahmoud, Humaid Khan

Sultan Qaboos University Journal For Science

Plasma composition which includes total protein, cholesterol, lactate, glucose, uric acid, urea, CO2, and electrolytes (Ca++, K+, Na+, Mg++, PO4-3, Cl-), and plasma osmolarity were analyzed in normal adult nesting green turtles Chelonia mydas. Blood samples were collected in June-October at the peak of the nesting season and in November-May during the non-peak period. Plasma electrolytes values, except for PO4-3 and Cl- were significant between the two periods. Values for total proteins and uric acid were significantly different during the two periods but urea values were insignificant. Osmolarity was unchanged during the two periods. During nesting the sea turtles undergo …

Go to article

Influence Of Aging Conditions On Fatigue Fracture Behaviour Of 6063 Aluminum Alloy, Rafiq Ahmed Siddiqui, Saeed Ali Al-Araimi, Ahmet Turgutlu Apr 2025

Influence Of Aging Conditions On Fatigue Fracture Behaviour Of 6063 Aluminum Alloy, Rafiq Ahmed Siddiqui, Saeed Ali Al-Araimi, Ahmet Turgutlu

Sultan Qaboos University Journal For Science

Aluminum - Magnesium - Silicon (Al-Mg-Si) 6063 alloy was heat-treated using under aged, peak aged and overage temperatures. The numbers of cycles required to cause the fatigue fracture, at constant stress, was considered as criteria for the fatigue resistance. Moreover, the fractured surface of the alloy at different aging conditions was evaluated by optical microscopy and the Scanning Electron Microscopy (SEM). The SEM micrographs confirmed the cleavage surfaces with well-defined fatigue striations. It has been observed that the various aging time and temperature of the 6063 Al-alloy, produces different modes of fractures. The most suitable age hardening time and temperature …

Go to article

Determination Of Sugar And Mineral Contents In Some Omani Fruits, Salma M. Z.Al-Kindy, Abdulrahman O. Abdulnour, Maryam M. Al-Rasbi Apr 2025

Determination Of Sugar And Mineral Contents In Some Omani Fruits, Salma M. Z.Al-Kindy, Abdulrahman O. Abdulnour, Maryam M. Al-Rasbi

Sultan Qaboos University Journal For Science

Omani fruits were analyzed for their reducing sugar, total sugar contents and some minerals. Among the minerals studied were Ca, Mg, Na, K and P. The amounts of total sugar and reducing sugar were within the range of values reported in the literature for the analysis of fruits conducted elsewhere. The amounts of the minerals differ from the reported literature values. This may be attributed to soil composition, climate and type of cultivar.

Go to article

Measurements Of Rf Radiation In The Vicinity Of Fm And Tv Broadcasting Stations, Abdulaziz S. Al-Ruwais Apr 2025

Measurements Of Rf Radiation In The Vicinity Of Fm And Tv Broadcasting Stations, Abdulaziz S. Al-Ruwais

Sultan Qaboos University Journal For Science

This paper provides measurements of power density around an FM and VHF-TV broadcasting station and its variation with distance. The maximum measured value was about 2.4 mW/cm2 at a height of 2 meters above ground level while the average value was fluctuating around 1 mW/cm2. It was found that the measured power density increases with height above ground and it reaches about 3.5 mW/cm2 at a height of about 15 meters at a location of about 400 meters from the station. At a nearer distance of 185 meters from the tower another measurement was taken at a height of 18 …

Go to article

Simple Formulae For Estimating The Depth And Dimension Of Some Geological Bodies From Gravity Anomalies, Sayyadul Arafin Apr 2025

Simple Formulae For Estimating The Depth And Dimension Of Some Geological Bodies From Gravity Anomalies, Sayyadul Arafin

Sultan Qaboos University Journal For Science

A simple method for determining the depth and radius of some simple geological bodies such as a sphere and a horizontal cylinder is presented. The method utilizes all of the data points to calculate the body parameters. The depth is estimated from the mean of the depths determined from various fractions of the maximum anomaly and their corresponding widths. The radii of the two bodies are calculated from the areas under the respective gravity profiles. Additionally , the radial symmetry of the gravity anomaly due to a sphere has been utilized to calculate the excess mass from a single profile. …

Go to article

Ergonomic Conditions In Small Manufacturing Industries, Ashraf A. Shikdar, Saeed A. Al-Araimi Apr 2025

Ergonomic Conditions In Small Manufacturing Industries, Ashraf A. Shikdar, Saeed A. Al-Araimi

Sultan Qaboos University Journal For Science

Ergonomic conditions in small manufacturing industries were investigated. Twenty seven managers of small manufacturing industries participated in the study. Old equipment and machines, poorly designed workplaces, lack of systematic planning, layout and organization, unsafe working conditions and poor environment were found common to these industries. Fifty-nine percent of companies indicated having equipment older than 15 years. Fifty-two percent of company managers reported receiving complaints of fatigue from their workforce, 41% complaints of back pain, and 33% complaints of upper-body pain. Seventy eight percent of companies reported a noisy environment (above 90 dBA) while 63% reported a hot environment. Management in …

Go to article

Approximating The Tail Probability Of The T-Distribution: A Bayesian Approach, Mohammad Fraiwan Al-Saleh Apr 2025

Approximating The Tail Probability Of The T-Distribution: A Bayesian Approach, Mohammad Fraiwan Al-Saleh

Sultan Qaboos University Journal For Science

A Bayesian technique is used to approximate the tail probability of the t-distribution. A set of upper and lower bounds are obtained for this probability. Based on their simplicity and accuracy, these bounds are very adequate to use. Some members of these bounds are compared to some existing approximations. The possibility of using this new procedure for some other distributions is explored.

Go to article

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, …

Go to article

Weak Complexes Of Sulfur Compounds With Halide Ligands, Salama B. Salama, Saad Wasif Apr 2025

Weak Complexes Of Sulfur Compounds With Halide Ligands, Salama B. Salama, Saad Wasif

Sultan Qaboos University Journal For Science

This review summarizes the study of the formation of SO2 -X- , SOCl2 -X- , SOBr2 -X- , SO2 Cl2 -X- complexes (X- = Cl- , Br- , I- , and SCN- ) in pure and mixed solvents of acetonitrile and dimethylsulfoxide over the past 30 years. Spectrometry (290nm-380nm) was the principal technique used for the investigation, since the enthalpies of formation Δ Hfo of the above complexes are low ( -6.03  -22.51 kJ/mol ). The stability of the complexes depend on the nature of the solvent, acceptor properties of the sulfur compounds, the donor properties of the halide …

Go to article

Dirhodium(Ii) Carbenes : The Chiral Product Cascade, Gregory H. P. Roos, Conrad E. Raab, Said Al-Hatmi Apr 2025

Dirhodium(Ii) Carbenes : The Chiral Product Cascade, Gregory H. P. Roos, Conrad E. Raab, Said Al-Hatmi

Sultan Qaboos University Journal For Science

The last decade has witnessed enormous growth in the spectrum of highly efficient asymmetric synthetic transformations. One prominent example of this progress is the application of dirhodium (II) carbenes generated from diazo- precursors. Innovative construction of ‘designer’ catalysts has played a integral role in extending the breadth of the synthetic cascade of non-racemic products now available through the range of cyclopropanation, C-X insertion, aromatic cycloaddition-rearrangement, and ylide-based reaction types. This review deals briefly with an overview of the important catalytic systems and maintains as its primary focus the cascade of diverse optically enriched products that flow from their applications.

Go to article

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 …

Go to article

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.

Go to article

State-Of-The-Art-Review Of Collapsible Soils, A. A. Al-Rawas Apr 2025

State-Of-The-Art-Review Of Collapsible Soils, A. A. Al-Rawas

Sultan Qaboos University Journal For Science

Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant …

Go to article

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 …

Go to article

Geological And Engineering Classification Systems Of Mudrocks, Amer Al-Rawas, Tariq Cheema, Mohammed Al-Aghbari Apr 2025

Geological And Engineering Classification Systems Of Mudrocks, Amer Al-Rawas, Tariq Cheema, Mohammed Al-Aghbari

Sultan Qaboos University Journal For Science

Mudrocks are a diverse group of very fine-grained argillaceous sedimentary rocks that are frequently encountered in most types of engineering projects. Upon excavation, the release of overburden stress and changes in the moisture content may cause certain apparently well indurated mudrocks to slake, producing a soil-like material. Because many mudrocks are nondurable, they have gained a reputation as problematic soft rocks. Geologists and engineers are confronted with the problem of selecting adequate parameters for accurately evaluating engineering behavior of mudrocks. The use of a single parameter (e.g. grain-size) is never considered to be enough and a combination of several parameters …

Go to article

Converged Networking: A Review Of Concepts And Technologies, Adel Ahmed Ali, Ahmed M. Al-Naamany Apr 2025

Converged Networking: A Review Of Concepts And Technologies, Adel Ahmed Ali, Ahmed M. Al-Naamany

Sultan Qaboos University Journal For Science

Converged networking is an emerging technology thrust that integrates voice, video, and data traffic on a single network. Converged networking encompasses several aspects, all of which are related to the aggregation of networking activity. Such aspects include, Payload convergence, Protocol convergence, Physical convergence, Device convergence, Application convergence, Technology convergence, etc. In recent years the Internet has developed into a global data network that is highly accepted as a multimedia information platform, which has the potential to develop into an alternative carrier network in the future. Several convergence scenarios have been recently proposed, ranging from integrating communication services and computer application …

Go to article

A Comprehensive Review Of Boundary Integral Formulations Of Acoustic Scattering Problems, S.I. Zaman Apr 2025

A Comprehensive Review Of Boundary Integral Formulations Of Acoustic Scattering Problems, S.I. Zaman

Sultan Qaboos University Journal For Science

This is a review presenting an overview of the developments in boundary integral formulations of the acoustic scattering problems. Generally, the problem is formulated in one of two ways viz. Green’s representation formula, and the Layer-theoretic formulation utilizing either a simple-layer or a double-layer potential. The review presents and expounds the major contributions in this area over the last four decades. The need for a robust and improved formulation of the exterior scattering problem (Neumann or Dirichlet) arose due to the fact that the classical formulation failed to yield a unique solution at (acoustic) wave-numbers which correspond to eigenvalues (eigenfrequencies) …

Go to article

Evolution Of Axial-Field Electrical Machines, Abdullah Al-Badi, Adel Gastli, Hadj Bourdoucen, Joseph Jervase Apr 2025

Evolution Of Axial-Field Electrical Machines, Abdullah Al-Badi, Adel Gastli, Hadj Bourdoucen, Joseph Jervase

Sultan Qaboos University Journal For Science

This paper is a review of axial-field electrical machines, which were at the origin of the invention of electrical machines such as the famous Faraday’s disk. The different configurations of the axial-field machines are presented along with their advantageous key steady state characteristics such as high efficiency and high power to weight ratio. The differences between axial-field machines and conventional radial-field machines are discussed. The disc-type axial-field electrical machines with permanent-magnet excitation seem to be among the best designs in terms of compactness, suitable shape, robustness, and electric characteristics. Axial-field machines are expected to be used in a large number …

Go to article

First Prev Next Last