Integrated Solar Panel Antennas for Cube Satellites

This thesis work presents an innovative solution for small satellite antennas by integrating slot antennas and solar cells on the same panel to save small satellite surface real estate and to replace deployed wire antennas for certain operational frequencies. The two main advantages of the proposed antenna are: 1) the antenna does not require an expensive deployment mechanism that is required by dipole antennas; 2) the antenna does not occupy as much valuable surface real estate as patch antennas. The antenna design is based on using the spacing between the solar cells to etch slots in these spaces to create radiating elements. The initial feasibility study shows it is realistic to design cavit-backed slot antennas directly on a solar panel of a cube satellite. Due to the volume of the satellite, it is convenient to design antennas at S band or higher frequencies. Although it is possible to design integrated solar panel antennas in lower frequencies, such research is not the scope of this thesis work. In order to demonstrate and validate the design method, three fully integrated solar panel antennas were prototyped using Printed Circuit Board (PCB) technology (PCB is a common solar panel material for small satellites). The first prototype is a circularly polarized antenna. The second is a linearly polarized two-element antenna array. The third prototype is a dual band linearly polarized antenna array. Measured results agree well with simulations performed using Ansoft\u27s High Frequency Structure Simulater (HFSS). The thesis also presents a feasibility study of optimization methods and reconfigurable solar panel antenna arrays. The optimization study explores methods to use genetic algorithms to find optimal antenna geometry and location. The reconfigurable study focuses on achieving different antenna patterns by switching on and off the slot elements placed around the solar cells on solar panels of a cube satellite. It is shown that the proposed integrated solar panel antenna is a robust and cost-effective antenna solution for small satellites. It is also shown that given a solar panel with reasonable size, one can easily achieve multiple antenna patterns and polarization by simple switching

Knowledge and Attitudes of Jordanian Dentists toward Speech Language Pathology

This study was conducted to assess dentists’ knowledge of normal speech-language development (NSLD), speech-language disorders (SLD), and speech-language pathology (SLPy) and to determine their general attitudes toward speech-language pathology (SLPy). A self-administered, web-based questionnaire was emailed to all members of the Jordanian Dental Association Council. 191 completed questionnaire were entered in excel sheet and statistically analyzed with IBM SPSS version 20 software. The respondents demonstrated insufficient knowledge regarding normal speech-language development and speech-language disorders. Additionally, the major¬ity of respondents reported a general impression that the speech-language pathologist has an important role in a health profession team (86.8%). However, they did poorly on the normal speech-language development questions (26%) as well as the speech-language disorders questions (18%). There were no statistically significant differences between different variables - age, gender, years of practice, place of practice and specialty of dentists and dentists’ knowledge of speech-language pathology

Sediment Yield Problems in Khassa Chai Watershed Using Hydrologic Models

Upland erosion and sedimentation are one of the severe problems which faces dams as sediments occupy spaces within reservoirs storage, hence, decreasing live water storage which is the main purpose of dam’s construction. Iraq is one of the countries that will face a significant shortage of water income as a result of both the increment in water demand and of the reduction of water shares from the source countries. Thus, the existing dams in Iraq represent a strategic resource to fulfill water demands, and the sedimentation at these dams is studied to assess the quantity of sediments that reach to these reservoirs and decrease available water volume and useful life of reservoir. In the current study, Khassa Chai Dam is located in the Northeast of Iraq and its main watershed basin covers an area of about 412 km2 between Kirkuk and Al Sulaymaniyah Governorates has been selected to estimate and predict the amount of sediment yield based on 30 years of daily climate data and the events of different intensity rainstorms. Automated geospatial watershed assessment (AGWA) tool model has been used to simulate Khassa Chai Dam catchment area. This model utilizes the geographic information system (GIS) application to analyze the required data from GIS layer for digital elevation model, soil type, land use, and land cover by interference with the required climate data. The key components of AGWA model are the soil and water assessment tool model and kinematic runoff and erosion (KINEROS) model which are able to simulate complex watershed behavior to explicitly account for spatial variability of soils, rainfall distribution patterns, and vegetation. The hydrologic characteristics for Khassa Chai catchment area according to the SWAT outputs show that the most erosive sub-basins are not able to deliver the eroded material or sediments to the reservoir due to their transmission losses, percolation, and other minor obstacles. KINEROS model simulation for sediment yield is much closer to the behavior of Khassa Chai watershed in erosion and sediment transport according to the single storm events and for individually selected sub-watersheds which are closed in their location to reservoir inlet

Echo state network for occupancy prediction and pattern mining in intelligent environment

Pattern analysis and prediction of sensory data is becoming an increasing scientific challenge and a massive economical interest supports the need for better pattern mining techniques. The aim of this paper is to investigate efficient mining of useful information from a sensor network representing an ambient intelligence environment. The goal is to extract and predict behavioral patterns of a person in his/her daily activities by analyzing the time series data representing the behaviour of the occupant, generated using occupancy sensors. There are various techniques available for analysis and prediction of a continuous time series signal. However, the occupancy signal is represented by a binary time series where only discrete values of a signal are available. To build the prediction model, recurrent neural networks are investigated. They are proven to be useful tools to solve the difficulties of the temporal relationships of inputs between observations at different time steps, by maintaining internal states that have memory. In this paper, a special form of recurrent neural network, the so-called Echo State Network (ESN) is used in which discrete values of time series can be well processed. Then, a model developed based on ESN is compared with the most popular recurrent neural net-works; namely Back Propagation Through Time (BPTT) and Real Time Recurrent Learning (RTRL). The results showed that ESN provides better prediction results compared with BPTT and RTRL. Using ESN, large datasets are learnt in only few minutes or even seconds. It can be concluded that ESN are efficient and valuable tools in binary time series prediction. The results presented in this paper are based on simulated data generated from a simulator representing a person in a 1 bedroom flat

Recurrence Relations for Moments of Dual Generalized Order Statistics from Weibull Gamma Distribution and Its Characterizations

In this paper, we establish explicit forms and new recurrence relations satisfied by the single and product moments of dual generalized order statistics from Weibull gamma distribution (WGD). The results include as particular cases the relations for moments of reversed order statistics and lower records.We present characterizations ofWGD based on (i) recurrence relation for single moments, (ii) truncated moments of certain function of the variable and (iii) hazrad function

Breathing Life Into Marketing Scholarship Through Creativity Learning and Teaching

Both employers and higher education institutes acknowledge creativity as a critical skill that all marketing graduates need to be equipped with when entering the job market. Creativity needs to exist within the marketing curriculum and be regarded as an integral part of the academic programmes offered at business schools. Whilst scholarly attempts have been made to find ways of incorporating creativity within the formal training at universities, many scholars acknowledge that creativity in marketing education has received little attention from researchers. This chapter highlights the importance of creative thinking for marketing and reviews the literature to provide a synthesis of the leading models for learning and teaching creativity in marketing modules

Kinetics of Surfactant Adsorption at Fluid-Fluid Interfaces: Surfactant Mixtures

The adsorption at the interface between an aqueous solution of several surface-active agents and another fluid (air or oil) phase is addressed theoretically. We derive the kinetic equations from a variation of the interfacial free energy, solve them numerically and provide an analytic solution for the simple case of a linear adsorption isotherm. Calculating asymptotic solutions analytically, we find the characteristic time scales of the adsorption process and observe the behavior of the system at various temporal stages. In particular, we relate the kinetic behavior of the mixture to the properties of its individual constituents and find good agreement with experiments. In the case of kinetically limited adsorption, the mixture kinetics is found to be considerably different from that of the single-surfactant solutions because of strong coupling between the species.Comment: 19 pages, 7 figures, to be published in Langmui

Mott scattering at the interface between a metal and a topological insulator

We compute the spin-active scattering matrix and the local spectrum at the interface between a metal and a three-dimensional topological band insulator. We show that there exists a critical incident angle at which complete (100%) spin flip reflection occurs and the spin rotation angle jumps by $\pi$. We discuss the origin of this phenomena, and systematically study the dependence of spin-flip and spin-conserving scattering amplitudes on the interface transparency and metal Fermi surface parameters. The interface spectrum contains a well-defined Dirac cone in the tunneling limit, and smoothly evolves into a continuum of metal induced gap states for good contacts. We also investigate the complex band structure of Bi$_2$Se$_3$.Comment: published versio