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Muscat, Oman

Ali R.,University of Jordan | Neill P.A.,University of Nevada, Reno | Beiersdorfer P.,Lawrence Livermore National Laboratory | Harris C.L.,Gulf College | And 2 more authors.
Astrophysical Journal Letters | Year: 2010

Experimental and theoretical state-selective X-ray spectra resulting from single-electron capture in charge exchange (CX) collisions of Ne10+ with He, Ne, and Ar are presented for a collision velocity of 933 km s -1 (4.54 keV nucleon-1), comparable to the highest velocity components of the fast solar wind. The experimental spectra were obtained by detecting scattered projectiles, target recoil ions, and X-rays in coincidence; with simultaneous determination of the recoil ion momenta. Use and interpretation of these spectra are free from the complications of non-coincident total X-ray measurements that do not differentiate between the primary reaction channels. The spectra offer the opportunity to critically test the ability of CX theories to describe such interactions at the quantum orbital angular momentum level of the final projectile ion. To this end, new classical trajectory Monte Carlo calculations are compared here with the measurements. The current work demonstrates that modeling of cometary, heliospheric, planetary, and laboratory X-ray emission based on approximate state-selective CX models may result in erroneous conclusions and deductions of relevant parameters. © 2010. The American Astronomical Society. All rights reserved. Source

Obaidy M.A.,Gulf College | Ayesh A.,De Montfort University
Sustainable Computing: Informatics and Systems | Year: 2015

Abstract In this work we are presenting the design of an intelligent hybrid optimization algorithm which is based on Evolutionary Computation and Swarm Intelligence to increase the life time of mobile wireless sensor networks (WSNs). It is composed of two phases; Phase-1 is designed to divide the sensor nodes into independent clusters by using Genetic Algorithms (GAs) to minimise the overall communication distance between the sensor-nodes and the sink-point. This will decrease the energy consumption for the entire network. Phase-2 which is based on Particle Swarm Optimization (PSO) is designed to keep the optimum distribution of sensors while the mobile sensor network is directed as a swarm to achieve a given goal. One of the main strengths in the presented algorithm is that the number of clusters within the sensor network is not predefined, this gives more flexibility for the nodes' deployment in the sensor network. Another strength is that sensors' density is not necessary to be uniformly distributed among the clusters, since in some applications constraints, the sensors need to be deployed in different densities depending on the nature of the application domain. Although traditionally Wireless Sensor Network have been regarded as static sensor arrays used mainly for environmental monitoring, recently, its applications have undergone a paradigm shift from static to more dynamic environments, where nodes are attached to moving objects, people or animals. Applications that use WSNs in motion are broad, ranging from transport and logistics to animal monitoring, health care and military. These application domains have a number of characteristics that challenge the algorithmic design of WSNs. © 2014 Elsevier Inc. All rights reserved. Source

Ali R.,University of Jordan | Beiersdorfer P.,Lawrence Livermore National Laboratory | Harris C.L.,Gulf College | Neill P.A.,University of Nevada, Reno
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2016

Charge-exchange collisions of slow Ne10+ ions with He, Ne, and Ar targets were studied with simultaneous x-ray and cold-target recoil-ion-momentum spectroscopy proving the contribution of several mechanisms to the radiative stabilization of apparent (4,4) doubly excited states for He and Ne targets and of (5,6) states for Ar. In particular, the stabilization efficiency of the mechanism of dynamic auto-transfer to Rydberg states is confirmed. Moreover, we present evidence for direct radiative decays of (4,4) states populated in collisions with He, which is an experimental indication of the population of so-called unnatural-parity states in such collisions. These mechanisms lead to the emission of x-rays that have considerably higher energies than those predicted by current spectral models and may explain recent observations of anomalously large x-ray emission from Rydberg levels. © 2016 American Physical Society. Source

Al-Azawi R.,Gulf College | Ayesh A.,University of Leicester
2015 International Conference on Open Source Software Computing, OSSCOM 2015 | Year: 2015

This paper describes a case study of how Agent Oriented Agile Based (AOAB) development methodology was implemented in mobile computing module to create game as a part of the module assessment requirements. Games can be used in higher education in many ways to increase students participation, enable variation in how lectures are taught and to increase students interest when they create their own game. We provide a new game development methodology and integrated with mobile computing module. The experience described in this paper is based on the feedback from the module staff member, students feedback, final student report and finally module evaluation report by students. The evaluation shows that the students who used AOAB methodology provide a better result rather than groups who used Agile game development methodology in game creation. Finally, we describe the benefit of using game in higher education and how we could enhance students progress in their study. © 2015 IEEE. Source

Harris K.J.,Florida State University | DiPietro R.B.,University of South Carolina | Murphy K.S.,University of Central Florida | Rivera G.,Gulf College
International Journal of Hospitality Management | Year: 2014

This study explores the relationship between the number of critical food safety violations and the restaurant's status as either a chain or independent foodservice provider and location. The State of Florida categorized the restaurant operations according to the type of license obtained, chain or independent. Chain restaurants are defined as multi-unit restaurants owned or operated by the same company or individual that total seven locations or more. Data for the current study was retrieved from the public records for the fiscal years 2009-2010 and 2010-2011. The study found that both the aggregate number of critical violations and risk factors and the number of individual critical violations and risk factors were significantly different among chain and non-chain restaurants in the state of Florida. Results indicate that the number of critical violations received is impacted by both the location of the restaurant and whether the restaurant is independently operated or a chain. The current study assists in explaining underlying reasons for repeated food safety violations despite Florida's required food safety training certification of restaurant managers and training of their staff; providing implications for academics and foodservice practitioners alike. © 2013 Elsevier Ltd. Source

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