bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of Decadal Precipitation over Nairobi in Kenya
Authors: Muthama Nzioka John , Moses Manene M. , Joseph Ndetei Cornelius 
Published: May 2017

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 of rainfall information that is explained by the variation in the independent (time) variable. From the results obtained, the stepwise regression technique selected the fourth degree polynomial as the best fit for analyzing the March-May (MAM) and October -December (OND) seasonal rainfall data set. Solar cycle period of ten (10) years was employed to get the fourth degree polynomial variables. Hence from the study, it can be deducted that the 4th degree polynomial function can be used to predict the peak and the general pattern of seasonal rainfall over Nairobi, with acceptable error values. This information can be used in the planning and management of water resources over Nairobi. The same information can be extended to other areas.
Transform Domain Characterization of Dual Group Codes of Cyclic Group Codes over Elementary Abelian Groups
Authors: Zain Adnan Abdulla 
Published: May 2017

The group of characters of an elementary Abelian group has been used to define duality between its subgroups, which in turn is extended to duality between group codes. The transform domain description of the dual codes of cyclic group codes of length over has been developed in this paper. Several example codes and their duals have been presented also.
Incidence Matrices of X-Labled Graphs and an Application
Authors: Jassim W.S. 
Published: May 2017

In this work, we have made some modifications on the definition of the incidence matrices of a directed graph, to let the incidence matrices to be more confident for X – Labeled graphs. The new incidence matrices are called the incidence matrices of X – Labeled graphs, and we used the new definition to give a computer program for Nickolas`s Algorithm .
An Approach to Analyze the Ambiguity in RNA Structure
Authors: Singh Shailendra , Singh Amardeep 
Published: May 2017

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 common to all, or a portion of, those sequences. Different types of analysis of a structure can provide functional information in different degrees of detail. In this This paper discusses various types of RNA secondary structure representation has been discussed and in which appropriate structure has been adopted or ‘can be adopted’ if this is for the first time as appropriate for a probabilistic approach that shows un-ambiguity avoids ambiguity.
Chiral Polyhedra Derived from Coxeter Diagrams and Quaternions
Authors: Koca Mehmet , Koca Nazife Ozdes , Al-Shueili Muna 
Published: May 2017

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 of chiral polyhedra. It is noted that vertices of the snub cube and snub dodecahedron can be derived from the vectors, which are linear combinations of the simple roots, by the actions of the proper rotation groupsand respectively. Their duals are constructed as the unions of three orbits of the groups of concern. We also construct the polyhedra, quasiregular in general, by combining chiral polyhedra with their mirror images. As a by-product we obtain the pyritohedral group as the subgroup the Coxeter group and discuss the constructions of pyritohedrons. We employ a method which describes the Coxeter groups and their orbits in terms of quaternions.
Effects of Pesticide Temephos on the Liver of Aphanius dispar (Rüppell 1828) (Pisces: Cyprinodontidae): A Microscopic Study
Authors: Ba-Omar Taher A. , Al-Kharusi Iman , Victor Reginald 
Published: May 2017

The effects of the pesticide temephos, at different concentrations, on the liver of Aphanius dispar, (Rüppell 1828) a cyprinodont fish, have been described. The changes in the liver tissue after exposure to 1 ppm, 5 ppm, 10 ppm and 25 ppm concentrations of temephos have been presented. Light and transmission electron microscopy showed that the degeneration of the liver cells commenced after exposure to 1 ppm and steadily progressed to show maximum changes at 25 ppm. Histopathological changes included the dilation of sinusoids, an increase in the number of lipid droplets and cytoplasmic vacuolation, pyknosis of the nuclei and focal necrosis. These results falsify the claim that temephos is a non-systemic poison.
Synthesis of Doped and non-Doped Nano MgO Ceramic Membranes
Authors: Labib Shiraz 
Published: May 2017

Doped and non-doped MgO coated thin films on alumina substrates were prepared using a chelating sol-gel method under controlled conditions to prepare nanomaterials with unprecedented properties. The effect of doping of ZnO on thermal, surface and structural properties was investigated using DTA-TG, BET and XRD respectively. Also microstructural studies and coating thickness measurements of MgO thin film were conducted using SEM. An increase in the thermal stability of MgO with increasing ZnO doping percent was observed. The increase of ZnO doping percent showed a marked decrease in the average particle size of MgO powder as a result of the replacement of some Mg2+ by Zn2+ which has similar ionic radius as Mg2+. This decrease in particle size of MgO was also related to the decrease of the degree of MgO crystalinity. The increase of ZnO doping also showed a marked decrease in coating thickness values of the prepared membranes. This decrease was related to the mechanism of ZnO doping into a MgO crystal lattice.
Neorotalia omanensis and Operculina musawaensis from the Sultanate of Oman
Authors: Al-Sayigh Abdul Razak Siddiq 
Published: May 2017

Two new species of larger benthic foraminifera, Neorotalia omanensis n. sp. and Operculina musawaensis n. sp. are described and illustrated from the eastern Oman Mountains. N. omanensis n. sp. occurs in the Musawa Formation in association with the planktonic foraminifera Morozovella edgari and Truncarotaloides topilensis indicating an early to middle Eocene age (P10-P13). Operculina musawaensis n. sp. occurs in the Abat Formation in association with the planktonic foraminifera Acarinina esnaensis and A. soldadensis indicating an early Eocene age (P6). This is the first known record showing the presence of genus Neorotalia in the Middle East. Representatives of the larger foraminiferal genus Linderina sp. are also described and illustrated from the Musawa Formation and compared with the published Linderina species in the surrounding countries.
Homotopy Perturbation Method For Fractional Shallow Water Equations
Authors: Al-Khaled Kamel , Al-Safeen M. K. 
Published: May 2017

In this paper, the homotopy perturbation method is adopted to find explicit and numerical solutions for systems of non-linear fractional shallow water equations. The fractional derivatives are described in the Caputo sense. We apply both the homotopy perturbation method and the homotopy analysis method, to solve certain shallow water equations with time-fractional derivatives, and explicitly construct convergent power series solutions. The results obtained reveal that these methods are both very effective and simple for finding approximate solutions. Some numerical examples and plots are presented to illustrate the efficiency and reliability of these methods.
Effect of Compositional Grading On reservoir Performance
Authors: Al-Rumhy M. , Al-Bemani A. , Boukadi F. 
Published: May 2017

In reservoirs with thickness exceeding fifty meters, compositional guiding has been found to cause significant variation in performance. Main fluid properties, governing the magnitude of reservoir performance, such as density; formation volume factor and fluid viscosity experience variation due to varying fluid composition along the hydrocarbon column. These variations cause erroneous estimation of stock-tank oil in place and may infer reservoir engineers to consider inappropriate secondary oil recovery methods, for example. In the presence of gravity segregation within the oil column, heavy ends will form a heavy oil blanket in the lower part of the reservoir. Such a scenario may result in poor displacement and an earlier breakthrough when water drive is the dominant fluid flow mechanism. In this paper reservoir performance due to varying reservoir fluid composition has been examined using reservoir simulation analysis and recommendations for better characterization of reservoir fluid sampling are outlined.
Magnetism in Iron-Zirconium Systems
Authors: Elzain M.E. , Al-Yousif A.D. , Gismelseed A.M. 
Published: May 2017

The discrete variational method is used to solve the Khon-Sham equation in the spin-polarized local density approximation for Fe-Zr and Fe-Zr-H clusters, representing iron-zirconium and hydrogenated iron-zirconium alloys. The local magnetic moment and hyperfine field at the Fe site were found to decrease, whereas the contact charge density and occupation number were found to increase with Zr contents. The Zr site in clusters with high Fe contents acquires a negative magnetic moment. When H is trapped at an interstitial site next-neighboring an Fe atom, the magnetic moment and hyperfine field are enhanced, while the contact charge density is reduced. ‘The opposite occurs when H occupies a neighboring interstitial site to Fe. For Zr atoms the local magnetic moment is found to become less negative with H at the neighboring position. We conclude from this calculation that H is trapped in Fe-Zr systems at positions which are nearest to Zr and next-nearest to Fe atoms.
Spin Torque Oscillator for High Performance Magnetic Memory
Authors: Sbiaa Rachid , Bouziane Khaled 
Published: May 2017

A study on spin transfer torque switching in a magnetic tunnel junction with perpendicular magnetic anisotropy is presented. The switching current can be strongly reduced under a spin torque oscillator (STO), and its use in addition to the conventional transport in magnetic tunnel junctions (MTJ) should be considered. The reduction of the switching current from the parallel state to the antiparallel state is greater than in the opposite direction, thus minimizing the asymmetry of the resistance versus current in the hysteresis loop. This reduction of both switching current and asymmetry under a spin torque oscillator occurs only during the writing process and does not affect the thermal stability of the free layer.
Model-Tracing Based Approach to Intelligent Program Diagnosis
Authors: Ramadhan Haider Ali 
Published: May 2017

Model-tracing based approach to intelligent program diagnosis and tutoring emphasizes the fact that the student’s design decisions are traced as the students develops the program Systems based on this model monitor the user's actions as the moves along the solution path, automatically analyzes partial solutions for semantic errors and misconceptions, and offers guidance whenever he deviates from the correct solution path. In this way, the system always checks to see if the student is following a design path of an idea model. Buggy paths are pruned as soon as they are discovered. Through this approach to automatic diagnosis and tutoring a model-tracing system can (1) diagnose very specific errors and misconceptions, and provide clear advice and explanation within proper and immediate context (2) simplify the engineering of automatic diagnosis by preventing multiple bugs and errors. However, this approach is very directive and interventionist. The users highly constrained in the solutions that can be developed, since he must conforms to the task decomposition and coding sequence enforced by model-tracing systems. This paper critically looks at model-tracing and suggests several solutions and guidelines for bypassing the shortcomings associated with the approach.
Calibration of Transit Operations Planning (TOP) Model and Evaluation of Bus Transit Route Performance in Riyadh
Authors: Koushki P.A. , Ali G.A. , Al-Nuaim Y.A. 
Published: May 2017

Public transit systems provide mobility for a large percentage of urban residents very cost-effectively and with minimum negative impact on the environment. ln spite of their vital and indispensable services; however , The majority of transit systems worldwide suffer from financial neglect and are forced to rely heavily on government subsidies for survival. In response to the rapidly shrinking funds and subsidy levels transit managements have to focus attention on ways to improve service operations. The management of public transit systems in Saudi Arabia is no exception to this trend. This study is aimed at evaluating the service performance of a sample of regular (fixed-route, fixed schedule) bus transit routes in Riyadh, Saudi Arabia. Utilizing a microcomputer-based program, the bus transit service operational measures of fare, headway, vehicle size and routing were analyzed. To account for the socio-economic and cultural differences of transit ridership in Riyadh, time/cost elasticities of demand as well as walk time and bus travel time parameters of the model were calibrated. Evaluation of the impact of changes in service operational measures suggested that no change in operational variables could improve the very low productivity of one of the sample study routes. A cost-reduction strategy which includes the use of smaller vehicles and less-frequent service runs should improve the low productivity of this route. Findings also indicated that a small increase in fare would pay for the total operation and maintenance costs of the other routes. The authors, however, do not recommend an increase in fare for a variety of reasons; the low income level of the captive riderships, the enormous financial resources of the country , and the multi-dimentional role of transit systems in providing urban mobility with minimum negative impacts on the environment.
Determination of Ascorbic Acid in Oman Citrus Fruits
Authors: Al-Kindi KS.M.Z. , Abdelnour A.O. , Al-Siyabi Rahma S. 
Published: May 2017

Omani citrus fruits were analyzed for their Vitamin C (ascorbic and AA) content by a titration method involving N-bromosuccinimide (NBS) as an oxidizing agent and by high performance liquid chromatography. Vitamin C content was also determined after storage at different temperatures. Vitamin C contents of the fruits were found to lie within the values reported in the literature.
On the Excitation of Instability Waves in Plane Poisuille Flow by a Concentrated Source at the Wall
Authors: Al-Maaitah Ayman 
Published: May 2017

The paper addresses the excitation of instability waves in plane Poiseuille flow by means of a concentrated source at the wall. The aim of this paper is to investigate the relation between the source amplitude and the excited wave amplitude for various flow and source parameters .The source is modeled by a time harmonic Dnae function and the generated disturbance is investigated By applying Founrier transform on the resulting linearized Navier-Stokes equation in the streamwise direction, the problem is resolved using inverse Fourier transform and the residue theorem. The theoretical formulation explains some observations by previous experiments on similar cases of excitation. Moreover, the calculations demonstrate that the disturbance amplitude increases as the excitation frequency decreases for a fixed Reynolds number, while, on the other hand, it increases as Reynolds number decreases for a fixed frequency.
Electromagnetic Modeling of the Propagation Characteristics of Satellite Communications Through Composite Precipitation Layers, Part1: Mathematical Formulation
Authors: Al-Rizzo H.M. , Al-Hafid H.T. , Tranquilla J.M. 
Published: May 2017

A systematic and general formulation of a Propagation Simulation Program (PSP) is developed for the coherent field of microwave and millimeter wave carrier signals traversing intermediate layered precipitation media, taking into account the random behavior of particle size, orientation, shape and concentration distributions. Based on a rigorous solution of the volumetric multiple-scattering integral equations, the formalism offers the capability of treating the potential transmission impairments on satellite-earth links and radar remote sensing generated by composite atmospheric layers of precipitation in conjunction with the finite polarization isolation of dual-polarized transmitting and receiving antennas. A multi-layered formulation is employed which encompasses an ensemble of discrete particles comprising an arbitrary mixture of ice crystals, melting snow and raindrops that may exist simultaneously along satellite-earth communication paths.
Variation in Seedling Characteristics of Five Populations of Acacia tortilis From the United Arab Emirates in Response to Increasing Sodium Chloride Concentrations
Authors: Al-Ansari Fatma. M. , Modawi Rashied. S. 
Published: May 2017

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 variations in the prevailing local conditions. Urbanization in the area and the changing water table may have divided A. tortilis into distinct subpopulations that are significantly different in seedling characteristics and their response to saline conditions.
Selection of Liner Materials and Design of Hazardous Water Facilities in Saudi Arabia
Authors: Abduljauwad Sahel N. , Dakkak Ali M. 
Published: May 2017

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 removal system for primary liners and leak detection/leachate collection and removal system for secondary liners.
Design of all Optical Packet Switching Networks
Authors: Mouftah Hussein T. 
Published: May 2017

Optical switches and wavelength converters are recognized as two of the most important DWDM system components in future all-optical networks. Optical switches perform the key functions of flexible routing, reconfigurable optical cross-connect (OXC), network protection and restoration, etc. in optical networks. Wavelength Converters are used to shift one incoming wavelength to another outgoing wavelength when this needs to be done. Always residing in optical switches, they can effectively alleviate the blocking probability and help solve contention happening at the output port of switches. The deployment of wavelength converters within optical switches provides robust routing, switching and network management in optical layer, which is critical to the emerging all-optical Internet. However, the high cost of wavelength converters at current stage of manufacturing technology has to be taken into consideration when we design node architectures for an optical network. Our research explores the efficiency of wavelength converters in a long-haul optical network at different degrees of traffic load by running a simulation. Then, we propose a new cost-effective way to optimally design wavelength-convertible switch so as to achieve higher network performance while still keeping the total network cost down. Meanwhile, the routing and wavelength assignment (RWA) algorithm used in the research is designed to be a generic one for both large-scale and small-scale traffic. Removing the constraint on the traffic load makes the RWA more adaptive and robust. When this new RWA works in conjunction with a newly introduced concept of wavelength-convertible switches, we shall explore the impact of large-scale traffic on the role of wavelength converter so as to determine the method towards optimal use of wavelength convertible switches for all-optical networks.
Simulation of m-Sequence’s Properties Through MATLAB-SIMULINK
Authors: Ahmad A. , Al-Mushrafi M. J. , Al-Busaidi S. 
Published: May 2017

Based on an analytical study of the theory of m-sequences, a tool is developed to facilitate practicing engineers to either generate m-sequence for its application, or to test applied m-sequence, or both. The developed test–kit simulates all the properties of m-sequences including number of 1s and 0s, the run lengths, pulse periods as well as autocorrelation properties. This simplified tool is developed using MATLAB–SIMULINK with required codes as well as desired blocks. The model is cost-effective and the output files of the generated SIMULINK models can be utilized in any software program or simulation procedures.
Multi-Agents Architecture for Scheduling and Control of Robotic Manufacturing Systems
Authors: Bouzouia Brahim 
Published: May 2017

This paper presents an innovative Multi-Agent approach related to an advanced real time control of flexible manufacturing systems. The proposed architecture is based on the paradigm of Distributed Intelligence and Multi-Agent Systems. The developed Multi-Agent prototype system integrates the following functions: Scheduling, dispatching, monitoring and error handling. A new negotiation protocol for manufacturing systems is presented in this paper. The purpose of this protocol is to assign dynamic operations to the resources of the Manufacturing System in order to accomplish the proposed tasks. This protocol is able to deal with exceptions.