Developing FPGA-based Embedded Controllers Using Matlab/Simulink

Field Programmable Gate Arrays (FPGAs) are emerging as suitable platforms for implementing embedded control systems. FPGAs offer advantages such as high performance and concurrent computing which makes them attractive in many embedded applications. As reconfigurable devices, they can be used to build the hardware and software components of an embedded system on a single chip. Traditional FPGA design flows and tools, requiring the use of Hardware Description Languages (HDLs), are in a different domain than standard control system design tools such as MATLAB/Simulink. This paper illustrates development of FPGA-based controllers by utilizing popular tools such as MATLAB/Simulink available for the design and development of control systems. The capability of DSP Builder is extended by developing a custom library of control system building blocks that facilitates rapid development of FPGA-based controllers in the familiar Matlab/Simulink environment. As a case study, this paper presents how the tools can be utilized to develop a FPGA-based controller for a laboratory scale air levitation system

Mineral content of the rocket plant (Eruca sativa)

Rocket (Eruca sativa) is an endemic species of the Brassicaceae family which is produced mostly in Mediterranean countries such as Italy, Greece and Turkey. Historical research has shown that rocket was used both as a garden plant and as a kind of herb or spice (Yaniv et al., 1998). According to data from the Turkish Statistics Foundation (TUIK) for the year 2010, Turkey’s rocket production in a year amounted to 4058 tonnes, and was used either raw in salads or cooked in various dishes. Apart from its use in nutrition, it is also used in the health and cosmetics industries as a result of the effectiveness of its phytochemical content. There have been few studies of these beneficial effects or of the mineral content of rocket; therefore, this study was performed as a survey, in which plant samples were collected from the province of Aydin in Turkey and evaluated for mineral content (N, P, K, Ca, Mg, Na, Fe, Cu, Mn and Zn). After chemical analysis of the samples by standard known methods, statistical analysis was performed using the statistics package SPSS 15.0. According to the results of these analyses, the average content of nutrient elements in rocket (Eruca sativa) was found as 4.32% N, 0.25% P, 5.13% K, 2.95% Ca, 0.58% Mg, 799.88 mgkg-1 Na, 350 mgkg-1 Fe, 5.36 mgkg-1 Cu, 40.58 mgkg-1 Mn and 64.86 mgkg-1 Zn. Minimum and maximum values are given together with average values. The aim of this study was to determine the mineral content of samples of rocket (E. sativa) grown by conventional methods in the province of Aydin, and to correlate this to previous studies.Key words: Rocket, arugula, Eruca sativa, rocket growing, mineral compositio

Hofstadter-Moir\'{e} Butterfly in Twisted Trilayer Graphene

Mirror symmetric twisted trilayer graphene (tTLG) is composed of even parity twisted bilayer graphene (tBLG)-like bands and odd parity Dirac-like bands. Here, we study the mirror-symmetric and mirror-asymmetric Hofstadter-Moir\'{e} (HM) fractal bands of tTLG. A novel quantum parity Hall state is identified in mirror-symmetric tTLG at experimentally accessible charge densities. This mirror symmetry-protected topological phase exhibits simultaneous quantized Hall and longitudinal resistances. The effects of the displacement field on the HM fractal bands of tTLG and topological phase transitions are also studied. The application of an electric displacement field results in an emergent weakly dispersive band at the charge neutrality point for a range of twist angles. This zero-energy state resides in the middle layer. It is isolated from the HM spectrum by an energy gap that scales proportional to the applied displacement field, making it a prime candidate to host correlated topological states

Quantum Hall Effects in Graphene-Based Two-Dimensional Electron Systems

In this article we review the quantum Hall physics of graphene based two-dimensional electron systems, with a special focus on recent experimental and theoretical developments. We explain why graphene and bilayer graphene can be viewed respectively as J=1 and J=2 chiral two-dimensional electron gases (C2DEGs), and why this property frames their quantum Hall physics. The current status of experimental and theoretical work on the role of electron-electron interactions is reviewed at length with an emphasis on unresolved issues in the field, including assessing the role of disorder in current experimental results. Special attention is given to the interesting low magnetic field limit and to the relationship between quantum Hall effects and the spontaneous anomalous Hall effects that might occur in bilayer graphene systems in the absence of a magnetic field

Coulomb impurity under magnetic field in graphene: a semiclassical approach

We address the problem of a Coulomb impurity in graphene in the presence of a perpendicular uniform magnetic field. We show that the problem can be solved below the supercritical impurity magnitude within the WKB approximation. Without impurity the semiclassical energies correctly reproduce the Landau level spectrum. For a given Landau level the WKB energy depends on the absolute value of angular momentum in a way which is consistent with the exact diagonalization result. Below the supercritical impurity magnitude, the WKB solution can be expanded as a convergent series in powers of the effective fine structure constant. Relevance of our results to validity of the widely used Landau level projection approximation is discussed.Comment: 10 pages, 5 figure

Transcutaneous Electrical Nerve Stimulation (TENS) A Possible Aid for Pain Relief in Developing Countries?

Transcutaneous electrical nerve stimulation (TENS) refers to the delivery of electrical currents through the skin to activate peripheral nerves. The technique is widely used in developed countries to relieve a wide range of acute and chronic pain conditions, including pain resulting from cancer and its treatment. There are many systematic reviews on TENS although evidence is often inconclusive because of shortcomings in randomised control trials methodology. In this overview the basic science behind TENS will be discussed, the evidence of its effectiveness in specific clinical conditions analysed and a case for its use in pain management in developing countries will be made