562 research outputs found

    Development of A New Algorithm For Optimal Solution Of Transportation Problems

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    This paper leads to an Algorithm/technique to solve optimal solution occurring in Transportation problems. In Transportation Problems by presenting a new algorithm to choose the Absolute differences of boundary cost cells. This New Algorithm lesser time than the existing Transportation method to get the optimal solution using initial basic feasible solution. Proposed technique/algorithm is better choice to get optimal solution without finding initial basic feasible solution and hence the proposed algorithm is useful to get optimal solution Transportation problems. Key words:- Transportation Problems, Absolute differences of boundary cost cells, Modified Distribution (M.O.D.I) Method, Initial Basic feasible solution, Optimum solution. DOI: 10.7176/MTM/9-1-0

    Investigating the Effect of Sintering Treatment on Structural and Magnetic Properties of Fe3O4 Nanoparticles

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    The magnetite Fe3O4 nanoparticles with a size range of 8-9 nm were synthesis by the chemical coprecipitation of ferrous chloride, ferric chloride and NaOH as reducing agent with some modifications in the reported methods. The synthesized magnetic nanoparticles were heated at different temperature in the range of 250 °C to 850 °C. The effect of heating on structural properties of synthesized sample was studied by X-ray diffraction (XRD) and field effect scanning electron microscope (FESEM). The XRD patterns confirm the formation crystalline phase of Fe3O4 nanoparticles. The pattern formation of the nanoparticles was observed upon sintering treatment. Also there was a phase transition from magnetite (Fe3O4) to hematite (α-F2O3) was observed when the samples was heated above 550 °C. The vibrating sample magnetometer (VSM) was used to study the magnetic properties, hysteresis curve and the saturation magnetisation. The saturation magnetisation decreases as the annealing temperature increases which is attributed to the phase transformation

    Solution processed PVB/mica flake coatings for the encapsulation of organic solar cells

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    YesOrganic photovoltaics (OPVs) die due to their interactions with environmental gases, i.e., moisture and oxygen, the latter being the most dangerous, especially under illumination, due to the fact that most of the active layers used in OPVs are extremely sensitive to oxygen. In this work we demonstrate solution-based effective barrier coatings based on composite of poly(vinyl butyral) (PVB)and mica flakes for the protection of poly (3-hexylthiophene) (P3HT)-based organic solar cells (OSCs)against photobleaching under illumination conditions. In the first step we developed a protective layer with cost effective and environmentally friendly methods and optimized its properties in terms of transparency, barrier improvement factor, and bendability. The developed protective layer maintained a high transparency in the visible region and improved oxygen and moisture barrier quality by the factor of ~7. The resultant protective layers showed ultra-flexibility, as no significant degradation in protective characteristics were observed after 10 K bending cycles. In the second step, a PVB/mica composite layer was applied on top of the P3HT film and subjected to photo-degradation. The P3HT films coated with PVB/mica composite showed improved stability under constant light irradiation and exhibited a loss of <20% of the initial optical density over the period of 150 h. Finally, optimized barrier layers were used as encapsulation for organic solar cell (OSC) devices. The lifetime results confirmed that the stability of the OSCs was extended from few hours to over 240 h in a sun test (65◦C, ambient RH%) which corresponds to an enhanced lifetime by a factor of 9 compared to devices encapsulated with pristine PVB.Higher Education Commission of Pakistan through NED University of Engineering and Technology, Karachi, Pakistan and “The APC was funded by Deanship of Scientific Research, King Saud University for funding through Vice Deanship of Scientific Research Chairs”

    Deposition and Characterization of Indium Selenide Thin Films for Opto-electronic Devices

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    Amongst all the III-VI semiconductors, ones that crystallize with a layered structure have gained special interest due to its significant usage in photovoltaic devices. III-VI layered semiconductor such as InSe has low density of dangling bonds on its surface therefore it is considered as vital material for the fabrication of opto-electronic devices like photo sensor, solar cell etc. In present work, InSe thin films were fabricated through a simple and facile drop-casting method, where the thin films were drop-casted between two silver paste electrodes on a glass substrate. The structural, surface morphological, compositional, electrical and optical properties of the prepared films were obsrved by XRD, SEM, EDAX, high precision digital multi-meter and UV-visible spectroscopy, respectively. XRD analysis of the prepared film shows the existence of nano-crystalline nature with monoclinic crystal structure of InSe. SEM images show good continuity of InSe film. InSe thin films are n-type with bandgap of 1.8 eV and their electrical conductivity is in the order of 10 – 10 S/cm that makes them appropriate for using as an absorber layer in the solar cell

    Process Parameter Optimization of a Polymer Derived CeramicCoatings for Producing Ultra-High Gas Barrier

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    YesSilica is one of the most efficient gas barrier materials, and hence is widely used as anencapsulating material for electronic devices. In general, the processing of silica is carried out at hightemperatures, i.e., around 1000◦C. Recently, processing of silica has been carried out from a polymercalled Perhydropolysilazane (PHPS). The PHPS reacts with environmental moisture or oxygen andyields pure silica. This material has attracted many researchers and has been widely used in manyapplications such as encapsulation of organic light-emitting diodes (OLED) displays, semiconductorindustries, and organic solar cells. In this paper, we have demonstrated the process optimization ofthe conversion of the PHPS into silica in terms of curing methods as well as curing the environment.Various curing methods including exposure to dry heat, damp heat, deep UV, and their combinationunder different environments were used to cure PHPS. FTIR analysis suggested that the quickestconversion method is the irradiation of PHPS with deep UV and simultaneous heating at 100◦C.Curing with this method yields a water permeation rate of 10−3g/(m2·day) and oxygen permeationrate of less than 10−1cm3/(m2·day·bar). Rapid curing at low-temperature processing along withbarrier properties makes PHPS an ideal encapsulating material for organic solar cell devices and avariety of similar applications.King Saud Universit

    The Effect of Conductor Line to Meander Line Antenna Design

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    In this paper, the meander line antenna has been designed to operate at 2.4-GHz for WLAN application. Two different designs of meander line antenna are investigated, without conductor line and with conductor line. The Microwave Office software is used for simulation design process. The antenna is fabricated on a doublesided FR-4 printed circuit board using an etching technique. The design has been tested with the Advantest Network Analyzer. The comparison between simulation and measurement results for the return loss and radiation patterns were presented. A bandwidth of 152MHz and return loss of -37.7dB were obtained at frequency 2.4GHz. The gain is comparable to microstrip yagi antenn

    D* Production in Deep Inelastic Scattering at HERA

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    This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel D+(D0Kπ+)π+D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ (+ c.c.) has been used in the study. The e+pe^+p cross section for inclusive D^{*\pm} production with 5<Q2<100GeV25<Q^2<100 GeV^2 and y<0.7y<0.7 is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {1.3<pT(D±)<9.01.3<p_T(D^{*\pm})<9.0 GeV and η(D±)<1.5| \eta(D^{*\pm}) |<1.5}. Differential cross sections as functions of p_T(D^{*\pm}), η(D±),W\eta(D^{*\pm}), W and Q2Q^2 are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and η\eta(D^{*\pm}), the charm contribution F2ccˉ(x,Q2)F_2^{c\bar{c}}(x,Q^2) to the proton structure function is determined for Bjorken xx between 2 \cdot 104^{-4} and 5 \cdot 103^{-3}.Comment: 17 pages including 4 figure

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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