Uniaxial Strain Effect on Graphene-Nanoribbon Resonant Tunneling Transistors

Graphene is an atomically thin two-dimensional (2-D) crystal with unique thermal, mechanical, and electronic transport properties such as the high mobility of carriers, perfect 2- D confinement and linear dispersion, etc., has been attracted many interest as a promising candidate for nano-scale devices over the past decades. Multilayer stacks of graphene and other stable, atomically thin, 2-D materials offer the prospect of creating a new class of heterostructure materials. Hexagonal boron- nitride (hBN), is a great candidate to be stacked with graphene due to an atomically 2-D layered structure with a lattice constant very similar to graphene (1.8% mismatch), large electrical band gap (∼4.7eV), and excellent thermal and chemical stability. The graphene/hBN based tunneling transistors show the resonant tunneling and strong negative differential resistance (NDR). These devices which have potential for future high-frequency and logic applications such as high-speed IC circuits, signal generators, data storage, etc., has been studied both theoretically and experimentally recently. The aim in this dissertation has been to study the effect of the uniaxial strain on the graphene nanoribbon resonant tunneling transistors (RTTs). The uniaxial strain may be induced either by an external stress applied to the graphene in a particular direction or by a substrate due to deposition of graphene on top of the other materials. The strain modifies distances between carbon atoms which leading to different hopping amplitudes among neighboring sites. A resonant tunneling transistor consisting of armchair graphene nanoribbon (AGNR) electrodes with three layers of hBN tunnel barrier between them has been considered. By using the nearest-neighbor tight-bind (TB) method and the nonequilibrium Green function (NEGF) formalism, the electronic transport characteristics of a RTT is calculated. In this work, we focus on how the strain affects the current-voltage characteristics of AGNR/hBN RTT

The radiated fields of the fundamental mode of photonic crystal fibers

The six-fold rotational symmetry of photonic crystal fibers has important manifestations in the radiated fields in terms of i) a focusing phenomena at a finite distance from the end-facet and ii) the formation of low-intensity satellite peaks in the asymptotic far field. For our study, we employ a surface equivalence principle which allows us to rigorously calculate radiated fields starting from fully-vectorial simulations of the near field. Our simulations show that the focusing is maximal at a characteristic distance from the end-facet. For large-mode area fibers the typical distance is of the order 10 Lambda with Lambda being the pitch of the triangular air-hole lattice of the photonic crystal fiber.Comment: 6 pages including 4 figures. Accepted for Opt. Expres

A Semi-Analytical Equation to Estimate Hydraulic Jump Length

Empirical methods for determining the length of hydraulic jump, including USBR graphical method are not accurate. In addition to reduced errors, providing an analytical equation will result in the possibility of programming and development of hydraulic software application. In this research, based on the principles of dimensional analysis, an analytical equation was achieved for estimating the length of hydraulic jump of E and classical type. Dimensionless coefficient of this equation was determined as a function of slope and Froude number using Table Curve software. For this purpose, 387 data series (258 calibration data and 129 validation data) of experiments conducted in this research, USBR studies, results of a research in the laboratory of Ohio University and in an appropriate range of the flume width, discharge, Froude number, the velocity before jump as well as the slope were used. At calibration stage, a simple equation was provided that indicates the hydraulic jump length in values Lj /y1 depends on the slope of the flume and Fr2 with determination coefficient of 94% and standard error less than 8%. Also at validation stage, the observed data and computed values was close to identity line with a determination coefficient of 0.97. Presenting the hydraulic jump length in values Lj /y1 versus Fr1 (which is very similar to USBR graphical method) was not satisfactory even with zoning Fr1

A tool for knowledge-oriented physics-based motion planning and simulation

The book covers a variety of topics in Information and Communications Technology (ICT) and their impact on innovation and business. The authors discuss various innovations, business and industrial motivations, and impact on humans and the interplay between those factors in terms of finance, demand, and competition. Topics discussed include the convergence of Machine to Machine (M2M), Internet of Things (IoT), Social, and Big Data. They also discuss AI and its integration into technologies from machine learning, predictive analytics, security software, to intelligent agents, and many more. Contributions come from academics and professionals around the world. Covers the most recent practices in ICT related topics pertaining to technological growth, innovation, and business; Presents a survey on the most recent technological areas revolutionizing how humans communicate and interact; Features four sections: IoT, Wireless Ad Hoc & Sensor Networks, Fog Computing, and Big Data Analytics.(Chapter) The recent advancements in robotic systems set new challenges for robotic simulation software, particularly for planning. It requires the realistic behavior of the robots and the objects in the simulation environment by incorporating their dynamics. Furthermore, it requires the capability of reasoning about the action effects. To cope with these challenges, this study proposes an open-source simulation tool for knowledge-oriented physics-based motion planning by extending The Kautham Project, a C++ based open-source simulation tool for motion planning. The proposed simulation tool provides a flexible way to incorporate the physics, knowledge and reasoning in planning process. Moreover, it provides ROS-based interface to handle the manipulation actions (such as push/pull) and an easy way to communicate with the real robotsPeer ReviewedPostprint (author's final draft

A Framework for Accessing Funds through Charitable Assignment of Property

Endowment has an old history and a long record and has been emphasized and ordered as a good tradition in Islam, but its dimensions and angles has not yet been considered by experts and economists. Expanding economic issues and their complexities, the role of endowment and endowed properties in economic development, and the need to fulfill the purposes of the Holy Legislator and benefactor indicate the need of revision in endowment in accordance with the conditions of that time and place. Endowment institution in the West, as a capable "financial institution"  in equipping the capital to solve social problems has a desirable position; while, despite having deep cultural and powerful religious stimuli, our society still could not use the capacities and capabilities of this good custom properly. Using the methods and new resources of financing in the development of and endowments are ways which suit to the changing circumstances of time and space, to use of high capacity of endowment. In this paper, after examining traditional and modern methods and sources of financing in the development of endowments, the necessity to use Sukuk as a new way of financing is emphasized, then, in the following, profiting Sukuk pattern as one of the new ways in financing in the development of endowments will be provided

Propagation of Light in Photonic Crystal Fibre Devices

We describe a semi-analytical approach for three-dimensional analysis of photonic crystal fibre devices. The approach relies on modal transmission-line theory. We offer two examples illustrating the utilization of this approach in photonic crystal fibres: the verification of the coupling action in a photonic crystal fibre coupler and the modal reflectivity in a photonic crystal fibre distributed Bragg reflector.Comment: 15 pages including 7 figures. Accepted for J. Opt. A: Pure Appl. Op

Growth Performance and Body Composition of Pikeperch (Sander lucioperca) Fingerlings under Dietary L-Carnitine

Abstract Growth performance, food efficiency and body composition of pikeperch (Sander lucioperca) were investigated with 1 or 2 g/kg L-carnitine added to the diet. Control diet did not contain L-carnitine. Two hundred pikeperch fingerlings (1.63 g, mean weight) were stocked in each 1 m3 concrete tank and fed equally 6 meals per day for 6 weeks. Higher increment in body weight (5.92 ± 0.37 g), the highest specific growth rate (3.75 ± 0.17) and food efficiency (98.04 ± 4.56), the highest crude protein (64.53 ± 0.84), the lowest crude lipid (21.59 ± 0.23) and significant (P<0.05) lowering in food conversion ratio (1.02 ± 0.05) were obtained with 2 g/kg L-carnitine diet. The greatest survival rate (84.88 ± 0.92) occurred when fingerlings were fed with 1 g/kg L-carnitine. Both treatments with L-carnitine showed lesser rate of cannibalism than in control (1.25± 0.09). Use of dietary L-carnitine improved growth performance and body composition of pikeperch fingerlings