2,134 research outputs found

    Photon signature analysis using template matching

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    We describe an approach to detect improvised explosive devices (IEDs) by using a template matching procedure. This approach relies on the signature due to backstreaming ? photons from various targets. In this work we have simulated cylindrical targets of aluminum, iron, copper, water and ammonium nitrate (nitrogen-rich fertilizer). We simulate 3.5 MeV source photons distributed on a plane inside a shielded area using Monte Carlo N-Particle (MCNP TM) code version 5 (V5). The 3.5 MeV source gamma rays yield 511 keV peaks due to pair production and scattered gamma rays. In this work, we simulate capture of those photons that backstream, after impinging on the target element, toward a NaI detector. The captured backstreamed photons are expected to produce a unique spectrum that will become part of a simple signal processing recognition system based on the template matching method. Different elements were simulated using different sets of random numbers in the Monte Carlo simulation. To date, the sum of absolute differences (SAD) method has been used to match the template. In the examples investigated, template matching was found to detect all elements correctly

    Resistivity network and structural model of the oxide cathode for CRT application

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    In this paper, the electrical properties of oxide cathode and oxide cathode plus, supplied by LG Philips Displays, have been investigated in relation to different cathode activation regimes and methods. Oxide cathode activation treatment for different durations has been investigated. The formations of the compounds associated to the diffusion of reducing elements (Mg, Al, and W) to the Ni cap surface of oxide cathode were studied by a new suggestion method. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) was used as analytical techniques. Al, W, and Mg doping elements take place during heating to 1080 K (Ni-Brightness) under a rich controlled Ba–SrO atmosphere through an acceleration life test. The chemical transport of these elements was occurred mainly by the Ni cap grain boundary mechanism with significant pile-up of Mg compounds. Al and W show a superficial concentrations and distribution. A new structural and resistivity network model of oxide cathode plus are suggested. The new structural model shows a number of metallic and metallic oxide pathways are exist at the interface or extended through the oxide coating. The effective values of the resistances and the type of the equivalent circuit in the resistivity network model are temperature and activation time dependent.</p

    An improved algorithm in test case generation from UML activity diagram using activity path

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    This paper proposed an improved algorithm to automatically generate test cases directly from UML activity diagram using an activity graph.This algorithm has been implemented as a prototype using UML activity diagrams as inputs to generate test cases.These generated test cases are generated automatically are compared to test cases that are generated manually in order to evaluate the algorithm’s usability and reliability.The result shows that the test cases generated by the developed test case generator program are the same as the one manually derived

    Color image encryption based on chaotic shit keying with lossless compression

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    In order to protect valuable data from undesirable readers or against illegal reproduction and modifications, there have been various data encryption techniques. Many methods are developed to perform image encryption. The use of chaotic map for image encryption is very effective, since it increase the security, due to its random behavior. The most attractive feature of deterministic chaotic systems is he extremely unexpected and random-look nature of chaotic signals that may lead to novel applications. A novel image encryption algorithm based on compression and hyper chaotic map techniques is proposed. Firstly the image is decomposed into three subbands R, G, and B then each band is compressed using lossless technique. The generated chaotic sequences from the 3D chaotic system are employed to code the compressed results by employing the idea of chaotic shift encoding (CSK) modulation to encode the three bands to generate the encrypted image. The experiments show that the proposed method give good results in term of security, feasibility, and robustness

    Antioxidant and antityrosinase activities of piper maingayi HK. Essential oils

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    The study was aimed to investigate the chemical components of stem and fruit volatile oils of Piper. maingayi Hk. with their antioxidant and antityrosinase activities. GC and GC-MS analysis of the essential oils obtained from the fresh stem and fruit of P. maingayi Hk. resulted in the identification of 34 and 18 components accounting for 83.6% and 78.7% of the total amount, respectively. Sesquiterpene hydrocarbons and oxygenated sesquiterpenes were the most highly represented classes as the former ranging from 64.7% to 70.7%, and the latter varying from 7.4% to 8.6%. The main constituents of the stem oil were: α-caryophyllene (26.2%), α-cedrene (8.4%), caryophyllene oxide (6.7%) and cis-calamenene (6.2%), while the fruit oil was dominated by δ-cadinene (22.6%), β-caryophyllene (18.8%), α-copaene (11.2%) and α-cadinol (7.1%). The stem and fruit of P. maingayi oils showed significant value for antioxidant and antityrosinase activities

    Effect of fractional crystallyzation on composition and thermal behavior of coconut oil

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    This study was aimed to fractionate coconut oil into its high- and low-melting fractions and determine the compositional and thermal property changes. A sample of coconut oil was dissolved in acetone, and allowed to crystallize isothermally at a desired temperature to separate into the low- and high-melting components. The isolated fractions were compared to the original sample with respect to fatty acid and triacylglycerol compositions as well as thermal behavior. There were considerable deviations in the fatty acid and triacylglycerol compositions of the two components with respect to those of the original sample. As a consequence, the overall melting behaviors of the two components differed considerably from that of the original sample. In the high-melting fraction, the onset and endset were shifted toward the higher temperature region with a concurrent reduction in its melting range, and vice-versa, the onset and endset of the low-melting fraction had shifted toward the low-temperature region with an increase in its melting range. The reduction of the melting range of the high-melting fraction could make it a specialty fat for applications in confectionery

    THE EFFECT OF THE AMMONIUM CONCENTRATION IN THE GROUNDWATER

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    Groundwater has long been one of the major water resources for a variety of domestic, agricultural, and industrial uses, particular for the regions with limited surface water resources (Zektser, I.S., &amp; Everett, L.G., 2000). This paper discuss to what extent the Ammonium concentration differences by making a comparison with the National Drinking Water Quality 1983 that states the permitted content of Ammonium is at 0.5 mg/l. The Ammonium content in Bachok district is quite a concern as from the data taken in 1990. 1999. and 2011, there’s only one observation well met the standard which is KB 51. KB 34 can be categorized as the most polluted, in 1990, the Ammonium concentration that has been recorded is at 11.2 mg/l. Anthropogenic activities such as urbanization is one of the major component that are causing the high NH4content in the ground water.&nbsp
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