bluuebunny/crossref_metadata_2025 huggingface dataset:
A Mixed GA and Tree-Gradient Method for Optimization of Distributed Generation
Authors: Max Chianca Pimentel Filho  , Manoel Firmino de Medeiros Jr.  , ClóvisBôsco MendonçaOliveira
Published: May 2017

Because of use of alternative energy sources, the number of small production plants connected to a distribution system tends to increase continuously, especially solar energy based on photovoltaic cells. It happens due to excess of energy production in homes, condos, trades or industries with own generation sources. The present work aims to develop a methodology to locate and size power generation units in distribution feeders so that system losses become minimal. The methodology uses initially the tree-gradient method to determine the total amount of power that must be injected at each network node, in order to minimize active losses. Then, a discretization process is adopted in order to allocate the whole optimal generation to a restricted subset of nodes that will be responsible for active generation. The methodology is complemented with a post-optimization algorithm that combines clustering, tree gradient method and a Genetic Algorithm (GA) to determine the best node(s) and the respective power(s) to be injected so that losses are minimal. The main result is the set of nodes where groups of consumers with own generation should be connected.
Alcohol-diesel fuel blends and their effect in performance and exhaust emissions
Authors: M.I. Gregorio Arenas  , M.D. Redel-Macías  , A. Ortega  , F.R. Lara  , M.P. Dorado
Published: May 2017

The growing demand of fossil fuel and the rising of its price strengthen the incessant search for energy alternatives. The use of alcohol-diesel fuel blends in diesel engines has recently received interest as an alternative fuel for use in spark ignition (SI) engine. However, little research concerning diesel fuel has been found. Moreover, alcohols can improve the combustion phase due to an increase of the oxygen content and reduce exhaust emissions as soot and particulate matter, besides knock. The most used alcohols in blends with diesel fuel are methanol and ethanol, butanol added recently. In contrast, there are very few studies about propanol and pentanol blended with diesel fuel, although engine results are remarkable. Some of them could be even produced via biorefinery, thus being better to the environment than the petroleum-based fuels. Nevertheless, the main challenge is to overcome disadvantages of alcohols including low lubricity, difficulty of vaporization and high auto ignition temperature and definitely, their well-know immiscible problem with diesel fuel being required co-solvents or emulsifiers. Besides, these additives are used to enhance the properties of the fuel, like the increase of the cetane number or the production of a stable blend.
Estimation and Forecast of Wind Power Generation by FTDNN and NARX-net based models for Energy Management Purpose in Smart Grids
Authors: A. Di Piazza  , M. C. Di Piazza  , G. Vitale
Published: May 2017

This paper is focused on the prediction and forecast of climate time series, particularly useful for planning and management of the power grid, by artificial neural networks. An appropriate prediction and forecast of climate variables, indeed, improves the overall efficiency and performance of renewable power plants connected to the power grid. On such a basis, the application of suitable Artificial Neural Networks (ANNs) to the field of wind power generation is proposed. In particular, two dynamic recurrent ANNs, i.e., the Focused Time-Delay Neural Network (FTDNN) and the Nonlinear autoregressive network with exogenous inputs (NARX), are used to develop a model for the estimate and forecast of daily wind speed. Results, applied to a turbine model, allow the produced power to be calculated for energy management and planning purpose in smart grids.
Comparison of Artificial Bee Colony Algorithm with other Algorithms used for Tracking of Maximum Power Point of Photovoltaic Arrays
Authors: B. Babar  , A. Crăciunescu
Published: May 2017

Maximum power point tracker (MPPT) is one of the key components of a solar electricity generation systems. It is used to extract the maximum power produced by an array of Photovoltaic cells. In this paper Artificial Bee Colony algorithm is analysed and implemented for tracking the maximum power point of Photovoltaic arrays. Furthermore the results obtained from ABC algorithm are compared with that of Perturb and Observe method, Fuzzy Logic Control and Genetic Algorithms.
Ageing of Electric Vehicle Battery considering Mobility Needs for Urban Areas
Authors: Maurici Yagües-Gomà  , Pol Olivella-Rosell  , Roberto Villafafila-Robles  , Andreas Sumper
Published: May 2017

This work seeks to analyse battery wear in electric vehicles (EV) based on daily usage and battery temperature. An agent-based model (ABM) was built, using Matlab® software, in order to evaluate users’ behaviour and represent the output data. Travel input data is obtained from Barcelona’s driving survey, and different models of battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), and electric motorcycles (EM) have been taken into consideration. Battery size characteristics and consumption are different for every model of vehicle, although only lithium ion (Li-ion) battery technology has been modelled and the same voltage profile has been used in all of them. The model successfully represents battery wear as a function of temperature and battery usage.
Prevalence and patterns of chronic disease multimorbidity and associated determinants in Canada
Authors: Roberts K. C. , Rao D. P. , Bennett T. L. , Loukine L. , Jayaraman G. C.
Published: May 2017

Introduction

Multimorbidity is increasingly recognized as a key issue in the prevention
and management of chronic diseases. We examined the prevalence and correlates of
chronic disease multimorbidity in the general adult Canadian population in relation to
age and other key determinants.

Methods

We extracted data from the Canadian Community Health Survey 2011/12 on
105 416 Canadians adults. We analysed the data according to the number of
multimorbidities (defined as 2+ or 3+ diseases from a list of 9) and examined the
determinants of multimorbidity using regression analyses.

Results

Our findings show that 12.9% of Canadians report 2+ chronic diseases and
3.9% report 3+ chronic diseases. Those reporting 3 or more chronic diseases were more
likely to be female, older, living in the lowest income quintile and to have not completed
high school. In the overall population, social deprivation is associated with a 3.7 odds of
multimorbidity, but when examined across age groups, the odds of multimorbidity were
notably higher in middle age, 7.5 for those aged 35 to 49 years and 5.4 for those aged 50
to 64 years.

Conclusion

As the proportion of Canadians living with multiple chronic diseases
increases, we need to assess chronic disease from a holistic perspective that captures
multimorbidity and upstream factors, to facilitate broader and more context-appropriate
associations with healthy living, quality of life, health care costs and mortality. Special
consideration should be given to the role that social deprivation plays in the
development of multimorbidity. Canadians living in the lowest socioeconomic group
are not only more likely to develop multimorbidity, but the onset of multimorbidity is
also likely to be significantly earlier.
Prévalence et profils de la multimorbidité au Canada et déterminants associés
Authors: Roberts K. C. , Rao D. P. , Bennett T. L. , Loukine L. , Jayaraman G. C.
Published: May 2017

Introduction

La prise en compte de la multimorbidité est de plus en plus reconnue comme un élément fondamental de la prévention et de la prise en charge des affections chroniques.
Cette étude porte sur la prévalence et les corrélats de la multimorbidité chez les adultes canadiens en fonction de l’âge et de certains autres déterminants clés.

Méthodologie

Nous avons extrait des données portant sur 105 416 adultes canadiens ayant répondu à l’Enquête sur la santé dans les collectivités canadiennes de 2011-2012. Nous les
avons analysées en fonction du nombre d’affections concomitantes présentes (deux ou plus ou trois ou plus, sur une liste de neuf) et nous avons cherché à caractériser les déterminants de la multimorbidité à l’aide de régressions.

Résultats

D’après notre analyse, 12,9 % des Canadiens souffraient de deux affections chroniques ou plus et 3,9 % de trois ou plus. Les répondants ayant déclaré souffrir de trois
affections chroniques ou plus étaient plus susceptibles d’être des femmes, d’être plus âgés, de faire partie d’un ménage dont le revenu fait partie du quintile le plus faible et
dont le niveau de scolarité le plus élevé de l’un des membres était inférieur aux études secondaires. La multimorbidité en lien avec le dénuement social était associée à une cote
de 3,7 dans la population en général, mais de 7,5 chez les 35 à 49 ans et de 5,9 chez les 50 à 64 ans, soit la population d’âge moyen.

Conclusion

La proportion de Canadiens atteints de multiples affections chroniques étant en augmentation, nous devons adopter, pour étudier les affections chroniques et leurs
facteurs en amont, une approche globale qui tienne compte de la multimorbidité, afin d’agir de manière globale et adaptée au contexte pour favoriser une vie saine et une meilleure
qualité de vie et pour réduire les coûts des soins de santé et la mortalité. On devrait particulièrement tenir compte du rôle joué par le dénuement social dans l’apparition de la
multimorbidité, car non seulement les Canadiens du groupe socioéconomique le plus démuni sont plus susceptibles de souffrir de multimorbidité, mais celle-ci surgira aussi
probablement beaucoup plus précocement.
Investigation of Facies Types and Associations of Kuhlan Red Bed Formation in NW Yemen: A New Hypothesis for Origin and Depositional Environment
Authors: Al-Wosabi Mohammed A. , Al-Mashaikie Sa’ad Z.
Published: May 2017

Varieties of thirteen facies types were recognized in the Kuhlan Formation represented by red bed siliciclastic sequences of argillaceous sediments. Examination of the Kuhlan stratigraphic column included sequence relationships, lithology, sedimentary characters, structures and petrography of the dominant rock types. These facies types are grouped in three distinct associations of facies. The lower unit A comprises association of facies (Distal turbidites) represented by alternates of turbidity sequences including sandstone, siltstone and thick shale beds. These facies types confirm a regressive depositional environment in deep marine shelf conditions. There are three facies types which are identified as massive sandstone, cross-bedded sandstone and pebbly sandstone facies. The middle unit B association of facies (Proximal turbedites) represents glaciomarine sequences displaying high lateral and vertical facies changes of glacioturbidite sediment alternates with diamictites and tillite beds. The sequences are affected by eustatic and eustatism of the glacial advance and retreat. This unit B includes eight types of facies. These are identified as; tillite, massive diamictites, stratified diamictites, laminated siltstone/shale, deformed siltstone/mudstone, graded rhythmic siltstone, massive conglomerate and cross-stratified sandy conglomerate facies. The upper unit C association of facies is represented by shallow marine shelf sequences displaying very thick massive and locally cross-bedded sand bar sandstone overlying the laminated siltstone/shale interbeds. The upward gradual changes in mineralogical composition and color confirms the start of marine transgression and later deposited platform Amran Group. Mineralogical composition of Kuhlan sandstone displays impure dirty rocks consisting of more than 30% of argillaceous matrix, 50% of cristobalite and quartz grains, more than 10% of ferruginous cement and 10% of detrital iron oxide grains, potash feldspar, igneous rock fragments and carbonate cement. It is classified as quartz greywacke type in the lower and middle parts and as quartz arenite with subarkoses in the upper part.
Synchronization and persistence in Diffusively Coupled Lattice Oscillators
Authors: Wasike Adu A.M. , Rotich K.T.
Published: May 2017

We consider the synchronization and persistence of a system of identical lattice oscillators that are diffusively coupled to their nearest neighbours. Each subsystem has a compact global attractor. This is done in the framework of invariant manifold theory. Normal hyperbolicity and its persistence are applied to obtain general conditions for the stability and robustness of the synchronization manifold. AMS(MOS) Subject classifications: 37C80, 37D10.
Kähler Manifolds Positive Ricci Curvature
Authors: Anchouche Boudjemaa
Published: May 2017

The aim of this paper is to give an overview of some results obtained in the field of Kähler manifolds of positive Ricci curvature.
Experimental Design for Nonlinear Problems
Authors: Abdelbasit K.M
Published: May 2017

Experimental designs for nonlinear problems have to a large extent relied on optimality criteria originally proposed for linear models. Optimal designs obtained for nonlinear models are functions of the unknown model parameters. They cannot, therefore, be directly implemented without some knowledge of the very parameters whose estimation is sought. The natural way is to adopt a sequential or Bayesian approach. Another is to utilize available estimates or guesses. In this article we provide a brief historical account of the subject, discuss optimality criteria commonly used for nonlinear models, the associated problems and ways of overcoming them. We also discuss issues of robustness of locally optimal designs. A brief review of sequential and Bayesian procedures is given. Finally we discuss alternative design criteria of constant information and minimum bias and pose some problems for future work.
Ornithopod and Sauropod Dinosaur Remains from the Maastrichtian Al-Khod Conglomerate, Sultanate of Oman
Authors: Schulp Ann S. , M.O'Connor Patrick , Weishampel David B. , Al Sayigh Abdul Razak , Al-Harthy Abdulrahman , Jagt John W.M. , Hartman Axel F.
Published: May 2017

Fieldwork in the Upper Cretaceous (Maastrichtian) Al-Khod Conglomerates in the Sultanate of Oman led to the discovery of a large bone fragment tentatively identified as a partial distal left humerus of a sauropod and an ornithopod dorsal vertebra. The very fragmentary state of preservation of the dorsal vertebra makes specific attribution difficult, but it shows remarkable similarities to the rhabdodontid dinosaurs Rhabdodon and Zalmoxes.
An Electrophoretic Study of LDH-Isozyme Distribution in Developing Embryonic and Adult Tissues of the Toad Bufo arabicus
Authors: Ambusaidi Intisar , Ba-Omar Taher , Al-Bahri Saif , Al-Shihi Aisha
Published: May 2017

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 response started. This isozyme showed gradual increase in intensity from stage 17 to stage 43.
Multiphase Mineral Inclusions in Ferrikaersutite Megacrysts : Implications for Postmagmatic Alteration of the Kaersutite Host
Authors: Nasir Sobhi
Published: May 2017

Primary and secondary multiphase mineral inclusions, without preserved fluid are found in ferrikaersutite megacrysts from the Cenozoic Harrat Ash Sham Volcanic Field in  ٍSyria. Mineral phases in the inclusions are magnetite, hematite, pseudobrookite and pyrrhotite. The kaersutite megacrysts formed from a hydrous basanitic melt at depth. Silicate minerals in the inclusions are olivine, plagioclase, phlogopite, hornblende, clino- and orthopyroxene. These silicate minerals crystallized from melt penetration and infillings of veins and fractures in the kaersutite. Magnetite and pyrrhotite inclusion formed through magmatic crystallization which was followed by low temperature alteration and re-equilibration. Late stage  near-surface alteration resulted in the formation of hematite,  limonite  and fine-grained weathering products  which comprise high-Fe-Si-,  Si-Mg-Al-,  Si-Fe-Al-,  Si-Al- and Si-Ti-Al-Fe-Ca-rich alterations. The composition of these late stage alteration products was governed by low-temperature post-magmatic alteration of kaersutite along cleavage planes and fractures.
General Screened Coulomb Potential : Nonperturbative Solutions
Authors: Sharma Lalit Kumar , Monowe Philip , Chimidza Samuel
Published: May 2017

Using nonperturbative solutions, the binding energies for different atoms have been evaluated for the screened Coulomb potentials. The variation of the wavefunction with distance  has also been studied. The results obtained are in excellent agreement with earlier calculations.
Lithofacies Attributes of a Transgressive Carbonate System : The Middle Eocence Seeb Formation, Al Khoud Area, Muscat, Oman
Authors: Hersi Osman Salad , AL-Harthy Abdulrahman
Published: May 2017

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. Prominent sedimentary structures in Unit III include hummocky and swaly cross-stratificiation, erosional surfaces, dewatering-induced deformations and laterally amalgamating beds. This unit represents sub-tidal sand shoals deposited in a storm-dominated shelf (between the fair-weather wave-base and storm-base). Unit IV is extensively burrowed, nodular, bioclastic wackestone to rudstone which is similar to Unit II in many aspects. Unit IV was deposited on the basinward side of the Unit III sand shoals below the reach of the storm-generated waves and currents. The uppermost Unit V is characterized by poorly-cemented bioclastic (large foraminiferal) rudstones with clay and silt-size quartz matrix. Bioclasts are generally intact with no apparent reworking. Deposition of Unit V is also envisaged as a low-energy, outershelf environment.
Convective Hydromagentic Slip Flow with Variable Properties Due to a Porous Rotating Disk
Authors: Rahman Mohammad M.
Published: May 2017

In this paper we investigate convective heat transfer characteristics of steady hydromagnetic slip flow over a porous rotating disk taken into account the temperature dependent density, viscosity and thermal conductivity  in the presence of  Hall current, viscous dissipation and Joule heating. Using von-Karman similarity transformations we reduce the governing equations for flow and heat transfer into a system of ordinary differential equations which are highly nonlinear and coupled. The resulting nondimensional equations are solved numerically by applying Nachtsheim-Swigert iteration technique. The results show that when modeling a thermal boundary layer, with temperature dependent fluid properties, consideration of Prandtl number as constant within the boundary layer, produces unrealistic results.   therefore  Therefore it must be treated as variable throughout the boundary layer. Results also show that the slip factor significantly controls the flow and heat transfer characteristics.
Robust Resistance Network Topology Design by Conic Optimization
Authors: Roos C. , Bai Y. , Chaerani D.
Published: May 2017

After a brief introduction to the field of Conic Optimization we present an application to the (robust) resistor network topology design problem, where the goal is to design an electrical network containing resistors, such that the dissipation is minimal, given the external current values at the nodes of the network and assuming that the conductance values satisfy some normalizing constraint. We present a linear model for the single-current case and semidefinite models for multi-current cases. All models are illustrated by examples.
A New Criterion for Optimality in Nonlinear Programming
Authors: Drummond L.M. Graña , Iusem A.N.
Published: May 2017

We establish a suﬃcient condition for the existence of minimizers of real-valued convex functions on closed subsets of ﬁnite dimensional spaces. We compare this condition with other related results.
Weakly Orthogonal Spherical Harmonics in a Non-Polar Spherical Coordinates and its Application to Functions on Cubed-Sphere
Authors: Faham M.A.A.M. , Nasir H.M.
Published: May 2017

In a recent paper (Nasir, 2007), a set of weakly orthogonal and completely orthogonal spherical harmonics in a non-polar spherical coordinate system based on a cubed-sphere was constructed. In this work, we explore some linear relations between these two sets of spherical harmonics. Moreover, a power representation for the set of weakly orthogonal spherical harmonics corresponding to a mode is presented. We also determine the norm of the orthogonal spherical harmonics and hence the inner products for the weakly orthogonal spherical harmonics. As an immediate application of these properties, we present a Fourier series formulation of spherical functions defined on the cubed-sphere.
A Galerkin Method for a Gaseous Ignition Model
Authors: Salman M. , Kim Jintae
Published: May 2017

We consider a Galerkin procedure to solve a parabolic integrodifferential equation that arises in a gas combustion model. This model has been proposed by Kassoy and Poland, and subsequently analyzed by Bebernes, Eberly and Bressan. The problem is formulated in the variational form. In order to estimate the error, some intermediate projection has been employed. Under certain conditions on the given data, the error estimate has been obtained. A fully descretized version by using an extrapolated Crank-Nicolson method has been applied and the order of convergence  derived.
Dihedral Groups as Epimorphic Images of Some Fibonacci Groups
Authors: Umar Abdullahi , Ali Bashir
Published: May 2017

The Fibonacci groups are deﬁned by the presentation where ,  and all subscripts are assumed to be reduced modulo . In this paper we give an alternative proof that for , ,  and  are all inﬁnite by establishing a morphism (or group homomorphism) onto the dihedral group  for all .
The effect of starvation on the liver of Aphanius dispar (Pisces; Cyprinodontidae): A microscopic study
Authors: Ba-Omar Taher A. , Al-Amri Mariam , Al-Belushi Jameela , Victor Reginald
Published: May 2017

Stress due to starvation is not an uncommon phenomenon in fresh-and brackish water fish living in arid environments. This study, a part of a larger investigation on the effects of stress due to starvation on the organ systems of Aphanius dispar, a cyprinodont fish in Oman, reports on the histopathological changes in the liver, using light and transmission electron microscopy.   The hepatocytes showed structural and ultrastructural changes in response to 24, 48, 72 and 96 hours of starvation.  The hepatocytes of the starved fish groups were characterized by a reduction in the size of their cells and their nuclei, chromatin condensation, loss of stored glycogen, large lipid droplets, wide intercellular spaces and the variable sizes of their mitochondria. Swirls of smooth endoplasmic reticulum (SER) were seen in some of the starved fish, which may indicate their involvement in lipid metabolism and the breakdown of glycogen. This paper makes a further contribution to the understanding of the physiology of fish in arid zones.
A Terbium Sensitized Luminescence Method for the Assay of Flubiprofen in Pharmaceutical Formulations
Authors: Al-Kindy Salma M.Z. , Al-Ghazali Arwa , Suliman Fakhr Eldin O. , Al-Lawati Haidar A.J.
Published: May 2017

A sensitive time-resolved luminescence method for the determination of flubiprofen (FLP) in methanol and in aqueous solution is described. The method is based on the luminescence sensitization of terbium (Tb3+ ) by the formation of a ternary complex with FLP in the presence of 4,7 diphenyl 1,10 phenanthroline (DPP) as co-ligand, and Tween-20 as surfactant. The signal for Tb-FLP-DPP was monitored at λex  = 285 nm and λem  = 552 nm. Optimum conditions for the formation of the complex in an aqueous system were TRIS buffer, pH 8.0, DPP (2.5Å~10−7  M), Tween-20 (0.30%) and 4Å~10-5  mol L-1  of Tb3+  which allowed the determination of 20–1000 ng mL-1  of FLP with a limit of detection (LOD) of 10 ng mL-1 . The relative standard deviations of the method ranged between 0.6 and 1.4% indicating excellent reproducibility of the method. The proposed method was successfully applied for the assays of FLP in pharmaceutical formulations and spiked tap water samples with average recoveries of 87% – 95%.
Determinants of Contraceptive Practice in Oman by Using Multilevel Modeling
Authors: Al-Balushi Moza S. , S. Ahmed Mohammed , Islam M. Mazharul
Published: May 2017

In this paper, multilevel logistic regression models are developed for examining the hierarchical effects of contraceptive use and its selected determinants in Oman using the 2008 Oman National Reproductive Health Survey (ONRHS). Comparison between single level and multilevel logistic regression models has been made to examine the plausibility of multilevel effects of contraceptive use. From the multilevel logistic regression model analysis, it was found that there is real multilevel variation among contraceptive users in Oman. The results indicate that a multilevel logistic regression model is the best fit over ordinary multiple logistic regression models. Generally, this study revealed that women’s age, education, number of living children and region of residence are important factors that affect contraceptive use in Oman. The effect of regional variation for age of women, education of women and number of living children further implies that there exists considerable differences in modern contraceptive use among regions, and a model with a random coefficient or slope is more appropriate to explain the regional variation than a model with fixed coefficients or without random effects. The study suggests that researchers should use multilevel models rather than traditional regression methods when their data structure is hierarchal.
Effect of Perpendicular Magnetic Field on Free Convection in a Rectangular Cavity
Authors: Kumar Anand , Singh Ashok K. , Chandran Pallath , Sacheti Nirmal C.
Published: May 2017

The steady free convective flow of a viscous incompressible and electrically conducting fluid in a two-dimensional cavity in the presence of a magnetic field applied normal to the plane of the cavity is investigated. The side vertical walls of the cavity are heated differentially while the horizontal walls are assumed to be insulated. The governing equations are re-formulated in terms of vorticity and stream function. The resulting boundary value problem is solved numerically using an alternating direction implicit (ADI) method. A number of plots illustrating the influence of Hartmann number and Rayleigh number on the streamlines and isotherms as well as the velocity and temperature profiles are shown. Furthermore, results for the average Nusselt number and the maximum absolute stream function have been obtained, and these are compared with the corresponding results in the literature when the magnetic field is applied along the cavity in the horizontal direction.
Detection of Unlabeled Genetically Modified Soybean in the Omani Market
Authors: Al-Sadqi Nabila , Alansari Aliya S.
Published: May 2017

This study aimed to screen for products containing Genetically Modified (GM) food in the Omani market using detection methods for the presence of Roundup Ready Soybean, Bt176 and MON810 maize in food products and to quantify it in positive samples using real time Polymerase Chain Reaction (PCR). A total of 100 food samples were collected randomly from markets in Oman. Out of 59 samples, 8  (13.5%) were successfully amplified with the maize plant specific PCR. GM screening showed negative for all samples, which indicated low or no GM maize in the samples tested. Out of 57 soy containing samples, 40 (70%) were successfully amplified by the soybean plant specific PCR. Six samples out of the 40 (15%) were found positive for GM using P35S-cf3/P35S-cr4 and HA-nos118-f/HA-nos118-r, primer pairs and using GMO5/GMO9 and GMO7/GMO8 primer pairs for specific detection of Roundup Ready Soybean. Real time PCR (TaqMan™ system) was carried out for the positive Roundup Ready Soybean samples and results showed that 2 out of the positive GM soy samples contained more than 5%; a Soy Formula for Infants (imported) sample contained 21% GM soybean and raw soybean seeds (imported in bulk amounts and packed in Oman)  contained 88% GM soybean. The results demonstrate for the first time the presence of GM-soy in food products in the Omani market, reinforcing the need for the use of qualitative and quantitative methods for GM detection in food products.
Kinematics of Post-obduction Deformation of the Tertiary Ridge at Al-Khod Village (Muscat, Oman)
Authors: Scharf Andreas , Mattern Frank , Al-Sadi Sawsan S.
Published: May 2017

Structural investigations in post-obductional Paleocene to Eocene limestones of the Tertiary Ridge reveal a ~1 km long WNW-ESE striking strike-slip fault system within the ridge, consisting of two main sub-parallel, strike-slip faults. Considering the geometry of the Harding Strain Ellipse, the orientation of structures between the two strike-slip faults (e.g., Riedel shears, folds, reverse faults) point to left-lateral motion. The abundance of large-scale folds (up to 100 m in wave length and amplitude) between the two strike-slip faults led us to the interpretation of transpressive conditions in a first approximation. Moreover, the Tertiary Ridge of the study area consists of three distinct structural domains. The faults of Domain A and C are oriented WNW-ESE, but the trend of the faults in the central Domain B differs by ~10°. The left-lateral strike-slip fault system exists only in Domain B. We propose that the direction of greatest stress during Miocene plate convergence (sigma 1) was oriented 032°/212°. Considering the trend of the strike-slip zone and the orientation of sigma 1, the left-lateral motion must have been transpressive. Sigma 1 is perpendicularly oriented to the domains A and C. Prior to the Miocene D2 compressional event the study area was affected by a D1 extensional event, related to the opening of the Red Sea and the Gulf of Aden or to gravity-driven normal faulting. The D2 compressional/transpressional structures of the Miocene are reactivating the D1 structures of the Oligocene.
Symmetry of the Pyritohedron and Lattices
Authors: Koca Nazife O. , Al-Mukhaini Aida Y. , Koca Mehmet , Al-Qanobi Amal J.
Published: May 2017

The pyritohedron consisting of twelve identical but non regular pentagonal faces and its dual pseudoicosahedron that possess the pyritohedral (Th) symmetry play an essential role in understanding the crystallographic structures with the pyritohedral symmetry. The pyritohedral symmetry takes a simpler form in terms of quaternionic representation. We discuss the 3D crystals with the pyritohedral symmetry which can be derived from the Coxeter-Dynkin diagram  of D3.
Towards Solutions of Seepage Problems
Authors: Al-Rawas A.A. , Al-Aghbari M.Y. , Sivakugan N. , Al-Shihi J.A.
Published: May 2017

Flow rates are traditionally used for solving seepage problems in soils. In this paper, the method of fragments is presented as a good alternative for solving seepage problems. A user friendly and interactive computer program for the method of fragments has been developed. Several randomly selected problems are solved by the flow net method, the method of fragments and the finite difference method. It was found that the method of fragments and the finite difference method gave very close predictions of the quantity of flow, exit gradient and uplift force. Furthermore, the effects of different positions and lengths, and number of sheet piles, and upstream blankets on the values of quantity of flow, exit gradient and uplift force are examined.
Synthesis of a Uniformly Spaced Array with Symmetric Amplitude Excitation by a Weighted Least-Square Method
Authors: Jervase J.A. , Zabalawi I.H.
Published: May 2017

A new, non-iterative  technique for synthesizing equispaced linear arrays with symmetric excitation is proposed. The methods is on the computation of an  eigenvector of an appropriate real, Symmetric and positive-definite matrix. This technique can be used to determine, given a n complete description of the desired radiation pattern, the array excitation coefficients . These derived excitation will produce, either exactly or approximately, the wanted antenna radiation pattern, depending on its complexity and the number of my elements. A number of design  examples are presented to illustrate the practicality and the potential of the proposed method.
Recursive Estimation in Capture-Recapture Methods
Authors: Aggoun Lakhdar , Elliott Robert J.
Published: May 2017

An important problem in statistical ecology is how to determine the size of an animal population. The best known technique is the capture-recapture technique. A random sample of individuals is captured, tagged in some way and released back into the population. After allowing time for the marked and unmarked individuals to mix sufficiently, a second random sample is taken and the marked ones are observed. Using measure change techniques, we estimate recursively conditional distributions of various quantities.
A Computer Aided Learning Tool for Readers
Authors: Yagi Sane M , Harous Saad
Published: May 2017

A bilingual piece of software has been developed to cultivate student speed and critical reading abilities by expanding their visual span, improving their eye movement, reducing their visual regression, developing their stock of vocabulary, and by honing their skimming, scanning, and critical understanding skills. This paper overviews the software, explains its educational value for language teaching, and experimentally demonstrates its utility.
Evolution of Axial-Field Electrical Machines
Authors: Al-Badi Abdullah , Gastli Adel , Bourdoucen Hadj , Jervase Joseph
Published: May 2017

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 of applications in the future owing to their special features and distinct advantages compared to conventional radial-field machines.
Modeling Flow and Transport in Unsaturated Porous Media: A Review
Authors: Al-Barwani H.H. , Al-Lawatia M. , Balakrishnan E. , Purnama A.
Published: May 2017

Underground water is a vital natural resource and every effort should be made to understand ways and means of efficiently using and managing it. The unsaturated zone, bounded at its top by the land surface and below by the water table, is the region through which water, together with pollutant carried by the water, infiltrates to reach the groundwater. Therefore, various processes occurring within the unsaturated zone play a major role in determining both the quality and quantity of water recharging into the groundwater. Classical methods of predicting water flow and contaminant transport processes in unsaturated porous media are generally inadequate when applied to natural soils under field conditions, due to the occurrence of macropores, structured elements and spatial variability of soil properties. Contaminant transport models also require the simultaneous solution of the unsaturated flow and transport equations. For applications to field conditions, numerical solutions and computer simulations based on numerical models have been increasingly used. Advances and progress in modeling water flow and contaminant transport in the unsaturated zones are reviewed, and specific research areas in need of future investigation especially relevant to Oman are outlined.
A Comprehensive Review of Boundary Integral Formulations of Acoustic Scattering Problems
Authors: Zaman S.I.
Published: May 2017

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) of the corresponding interior scattering problem. Moreover, this correlation becomes more pronounced as the wave-numbers become larger i.e. as the (acoustic) frequency increases. The robust integral formulations which are discussed here yield Fredholms integral equations of the second kind which are more amenable to computation than the first kind. However, the integral equation involves a hypersingular kernel which creates ill-conditioning in the final matrix representation. This is circumvented by a regularisation technique. An extensive useful list of references is also presented here for researchers in this area.
Dirhodium(II) Carbenes : The Chiral Product Cascade
Authors: Roos Gregory H. P. , Raab Conrad E. , Al-Hatmi Said
Published: May 2017

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.
Review of Omani Aflaj Systems: an Element of National Water Resources,Technology and Economic Developments
Authors: M. Shahalam Abulbasher
Published: May 2017

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.
Measurements of RF Radiation in the Vicinity of FM and TV Broadcasting Stations
Authors: Al-Ruwais Abdulaziz S.
Published: May 2017

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 meters, the power density increased to 41 mW/cm2.
Ergonomic Conditions in Small Manufacturing Industries
Authors: Shikdar Ashraf A. , Al-Araimi Saeed A.
Published: May 2017

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 44% of the companies acknowledged failure to ensure safety rules and 48% did not provide training on manual material handling. Lack of skills in ergonomics and training, communication and resources are believed to be some of the factors contributing to the poor ergonomic conditions in a sample of small manufacturing industries in Malaysia.
Simple Formulae for Estimating the Depth and Dimension of Some Geological Bodies From Gravity Anomalies
Authors: Arafin Sayyadul
Published: May 2017

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. The radius determined from the excess mass is independent of depth estimate. This method of determining the radius is more robust than the one based on calculating the area.  An error analysis showing the effects of truncation and zero-level errors on the estimated radius  is  also discussed.
Approximating the Tail Probability of the t-Distribution: A Bayesian Approach
Authors: Al-Saleh Mohammad Fraiwan
Published: May 2017

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.
An Assessment of Solid Waste and Landfilis in Muscat Area, Oman
Authors: El-Zawahry Alaa , Shahalam Abulbasher M. , Taha Ramzi , Al-Busaidi Turki
Published: May 2017

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 the years while the amounts generated from private sources such as industries and commercial centers increased during the same period. This is due to the fact that the Sultanate of Oman is developing very fast with increasing industrial, commercial and residential activities. About 80 % of the solid wastes is organic materials. This amount is high when compared to figures found in western countries. The data indicate that about 40 percent of the solid wastes are composed of recoverable materials. The concerned authorities should encourage the growth of industries to be involved in recycling business. Such activities will reduce the solid waste discharge in landfills and increase nearly 1.6 folds the expected life of existing landfills. A survey of the operating landfills indicate that the operational efficiency may be substantially improved by incorporating measures that deal with problems of gas production and leachate movements. The paper includes a detailed discussion of the problem and makes recommendations for possible future actions.
Use of Isotope and Solute Chemistry to Define the Sources of Pollution in Mawqaq Groundwater, Hail, Saudi Arabia
Authors: Al-Sagaby Ibrahim Abdulaziz , Moallim Mohamed Ali
Published: May 2017

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 in the study area. Coliform bacteria have also been identified in some wells. Application of stable isotope has shown the age, origin and the sources of the pollution in the groundwater of Mawqaq area. Appropriate health and municipal authorities of the area have initiated remedial measures and a monitoring program is to be implemented in coordination with these authorities.
Characteristic and Non-Characteristic Harmonics, Harmonic Cancellations and Relevant International Standards in Variable Speed Drives
Authors: Islam Syed M.
Published: May 2017

This paper will present a review of characteristic harmonics in both single phase and three phase drive front end rectifiers, discuss recent research findings in identifying sources and production of non-characteristic harmonics and amplification of harmonic levels when the front end rectifiers are fed from non-ideal supply conditions. Significant amount of triplens may be generated due to unbalances in utility supply voltage wave form and anticipated harmonic levels may vary widely. The paper will also discuss international harmonic standards such as the AS 2279, IEEE 519, and IEC 61000 series applicable to rectifier loads. Finally, the paper will present techniques to reduce harmonic levels by mixing of single phase and three phase non-linear loads resulting from mutual cancellations.