1,168 research outputs found

    Aplikasi Pengontrolan Robot Pemantau dari Udara Berbasis Android

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    Penelitian ini bertujuan untuk membuat Aplikasi pengontrolan robot pemantau dari udara berbasis Android untuk memantau daerah yang berbahaya atau daerah dengan ketinggian tertentu yang sulit dijangkau oleh manusia. Hardware yang digunakan berupa Helicopter R/C yang dimodifikasi dengan menambahkan kamera IP serta remote control yang terhubung dengan Arduino Uno dan Arduino Ethernet Shield. Sistem ini dilengkapi dengan aplikasi pengontrolan robot dan kamera untuk melakukan pemantauan dan proses pengambilan gambar dengan menggunakan jaringan wireless. Jaringan wireless berfungsi sebagai media transmisi data berupa gambar dan dapat menampilkan hasil pemantauan object kepada user, melalui layar tablet-PC yang menggunakan sistem operasi mobile berbasis Android. Metode pengembangan yang digunakan dalam pembuatan aplikasi pengontrolan ini adalah metode prototype, dengan bahasa pemrograman untuk pengembangan aplikasi yaitu Java Android dan bahasa pemrograman C yang digunakan untuk pengembangan perangkat pengontrol. Hardware dan software dalam penelitian ini dapat berfungsi sesuai dengan rancangan. Dengan aplikasi pengontrolan robot pemantau dari udara berbasis android ini dapat membantu user untuk melakukan observasi di suatu daerah

    Stereoselective synthesis of a-Amino-C-phosphinic acids and derivatives

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    a-Amino-C-phosphinic acids and derivatives are an important group of compounds of synthetic and medicinal interest and particular attention has been dedicated to their stereoselective synthesis in recent years. Among these, phosphinic pseudopeptides have acquired pharmacological importance in influencing physiologic and pathologic processes, primarily acting as inhibitors for proteolytic enzymes where molecular stereochemistry has proven to be critical. This review summarizes the latest developments in the asymmetric synthesis of acyclic and phosphacyclic a-amino-C-phosphinic acids and derivatives, following in the first case an order according to the strategy used, whereas for cyclic compounds the nitrogen embedding in the heterocyclic core is considered. In addition selected examples of pharmacological implications of title compounds are also disclosed

    Photoelectron diffraction: from phenomenological demonstration to practical tool

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    The potential of photoelectron diffraction—exploiting the coherent interference of directly-emitted and elastically scattered components of the photoelectron wavefield emitted from a core level of a surface atom to obtain structural information—was first appreciated in the 1970s. The first demonstrations of the effect were published towards the end of that decade, but the method has now entered the mainstream armoury of surface structure determination. This short review has two objectives: First, to outline the way that the idea emerged and the way this evolved in my own collaboration with Neville Smith and his colleagues at Bell Labs in the early years: Second, to provide some insight into the current state-of-the art in application of (scanned-energy mode) photoelectron diffraction to address two key issue in quantitative surface structure determination, namely, complexity and precision. In this regard a particularly powerful aspect of photoelectron diffraction is its elemental and chemical-state specificity

    Photoelectron diffraction investigation of the structure of the clean TiO2(110)(1×1) surface

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    The surface relaxations of the rutile TiO2(110)(1×1) clean surface have been determined by O 1 s and Ti 2p3∕2 scanned-energy mode photoelectron diffraction. The results are in excellent agreement with recent low-energy electron diffraction (LEED) and medium energy ion scattering (MEIS) results, but in conflict with the results of some earlier investigations including one by surface x-ray diffraction. In particular, the bridging O atoms at the surface are found to relax outward, rather than inward, relative to the underlying bulk. Combined with the recent LEED and MEIS results, a consistent picture of the structure of this surface is provided. While the results of the most recent theoretical total-energy calculations are qualitatively consistent with this experimental consensus, significant quantitative differences remain

    The local adsorption structure of benzene on Si(001)-(2 × 1): a photoelectron diffraction investigation

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    Scanned-energy mode C 1s photoelectron diffraction has been used to investigate the local adsorption geometry of benzene on Si(001) at saturation coverage and room temperature. The results show that two different local bonding geometries coexist, namely the 'standard butterfly' (SB) and 'tilted bridge' (TB) forms, with a composition of 58 ± 29% of the SB species. Detailed structural parameter values are presented for both species including Si–C bond lengths. On the basis of published measurements of the rate of conversion of the SB to the TB form on this surface, we estimate that the timescale of our experiment is sufficient for achieving equilibrium, and in this case our results indicate that the difference in the Gibbs free energy of adsorption, ΔG(TB)−ΔG(SB), is in the range −0.023 to +0.049 eV. We suggest, however, that the relative concentration of the two species may also be influenced by a combination of steric effects influencing the kinetics, and a sensitivity of the adsorption energies of the adsorbed SB and TB forms to the nature of the surrounding benzene molecules

    Flexible access to conformationally-locked bicyclic morpholines

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    A preparatively accessible route to a series of conformationally-locked bicyclic morpholines has been developed. This flexible approach allows for diversification in order for a small array of lead-like scaffolds to be synthesised from readily available key building blocks

    Nanocrystalline tin oxide nanofibers deposited by a novel focused electrospinning method. Application to the detection of TATP precursors

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    A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP) in air in the ppm range. High and fast responses to these gases have been obtained. © 2014 by the authors; licensee MDPI, Basel, Switzerland.This work has been supported by the Spanish Science and Innovation Ministry under the projects TEC2010-21357-C05-04 and TEC2013-48147-C6-4-R. Authors want to thank University of Extremadura for SEM and XRD analysis. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe

    Remote Substituent Effects on the Stereoselectivity and Organocatalytic Activity of Densely Substituted Unnatural Proline Esters in Aldol Reactions

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    The organocatalytic activities of highly substituted proline esters obtained through asymmetric [3+2] cycloadditions of azomethine ylides derived from glycine iminoesters have been analyzed by 19F NMR and through kinetic isotope effects. Kinetic rate constants have been determined for unnatural proline esters incorporating different substituents. It has been found that exo-L and endo-L unnatural proline methyl esters yield opposite enantiomers in aldol reactions between cyclic ketones and aromatic aldehydes. The combined results reported in this study show subtle and remote effects that determine the organocatalytic behavior of these synthetic but readily available amino acid derivatives. These data can be used as design criteria for the development of new pyrrolidine-based organocatalysts.Financial support was provided by the Spanish Ministerio de Economía y Competitividad (MINECO) and the Fondo Europeo de Desarrollo Regional (FEDER) (projects CTQ2010-16959/BQU, CTQ2012-35535, CTQ2013-40855-R, CTQ2007-62771/BQU, CTQ2010-20387, CTQ2010-17436, and Consolider-Ingenio CSD2007-00006), the University of the Basque Country (UPV/EHU, UFI11/22 QOSYC), the Basque Government (GV/EJ, grant IT-324-07), the Generalitat Valenciana-FEDER (PROMETEO/2009/039), the Gobierno de Aragón-FSE (research group E40), and the University of Alicante. M. d. G. R. thanks the Donostia International Physics Center (DIPC) for a postdoctoral contract. M. S. and L. C. gratefully thank MINECO for a contract funding their PhD projects
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