286 research outputs found

    Kemitraan Pemerintah dan Swasta dalam Pembangunan Bandara Swadaya Sangia Nibandera Kabupaten Kolaka

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    Penelitian ini bertujuan menjelaskan konsep kemitraan dalam pembangunan bandara Swadaya di Kabupaten Kolaka, dengan melihat dari mekanisme, struktur dan insentif dari kemitraan.Metode yang digunakan adalah metode kualitatif deskriptif. Data dianalisis dengan reduksi data, penyajian data, dan menarik kesimpulan.Hasil Penelitian ini menunjukkan bahwa dari pelaksanaan kemitraan antara Pemerintah Kabupaten Kolaka dan Swasta dalam Pembangunan Bandar Udara Swadaya Sangia Nibandera di Kabupaten Kolaka diihat dari mekanisme, struktur dan insentif terlaksana dengan baik dan efektif. Dari pelaksanaan kemitraan ini memberikan manfaat bagi masyarakat Kabupaten Kolaka dengan meningkatnya pendapatan dan juga memudahkan masuknya Investor di Kabupaten Kolaka

    Magnetic oscillations in planar systems with the Dirac-like spectrum of quasiparticle excitations II: transport properties

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    The quantum magnetic oscillations of electrical (Shubnikov de Haas effect) and thermal conductivities are studied for graphene which represents a distinctive example of planar systems with a linear, Dirac-like spectrum of quasiparticle excitations. We show that if a utmost care was taken to separate electron and phonon contributions in the thermal conductivity, the oscillations of electron thermal conductivity, κ(B)\kappa(B) and the Lorenz number, L(B)L(B) would be observable in the low field (less than a few Teslas) regime.Comment: 11 pages, RevTeX4, 6 EPS figures; 2 references, 1 figure and one more section are added; final version published in PR

    The Fulde-Ferrell-Larkin-Ovchinnikov State in the Organic Superconductor k-(BEDT-TTF)2Cu(NCS)2 as Observed in Magnetic Torque Experiments

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    We present magnetic-torque experiments on the organic superconductor k-(BEDT-TTF)2Cu(NCS)2 for magnetic fields applied parallel to the 2D superconducting layers. The experiments show a crossover from a second-order to a first-order transition when the upper critical field reaches 21 T. Beyond this field, which we interpret as the Pauli limit for superconductivity, the upper critical field line shows a pro-nounced upturn and a phase transition line separates the superconducting state into a low- and a high-field phase. We interpret the data in the framework of a Fulde-Ferrell-Larkin-Ovchinnikov state.Comment: 2 pages, 1 figur

    Field dependent effective masses in YbAl3_{3}

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    We show for the intermediate valence compound YbAl3_{3} that the high field (40 B\lesssim B \lesssim 60T) effective masses measured by the de Haas-van Alphen experiment for field along the direction are smaller by approximately a factor of two than the low field masses. The field BB^{*} \sim 40T for this reduction is much smaller than the Kondo field BKkBTK/μBB_{K} \sim k_{B}T_{K}/\mu_{B} (TKT_{K}\sim 670K) but is comparable to the field kBTcoh/μBk_{B}T_{coh}/\mu_{B} where TcohT_{coh}\sim 40K is the temperature for the onset of Fermi liquid coherence. This suggests that the field scale BB^{*} does not arise from 4ff polarization but is connected with the removal of the anomalies that are known to occur in the Fermi liquid state of this compound.Comment: 7 pages plus 3 figures Submitted to PRL 9/12/0

    Choriocapillaris impairment around the atrophic lesions in patients with geographic atrophy: A swept-source optical coherence tomography angiography study

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    Aims To evaluate the choriocapillaris (CC) flow alterations around geographic atrophy (GA) in eyes with dry age-related macular degeneration. Methods Using a swept-source optical coherence tomography angiography (SS-OCTA) device, two volume 6 76 mm scans were acquired in patients with GA presenting between June and December 2017 at the Doheny-UCLA Eye Centers. The area of GA was delineated on the en face structural OCT fundus images. For each eye, the en face OCTA slabs at the level of the CC from the two acquisitions were averaged and compensated for signal loss using the corresponding structural en face images. The resulting images were binarised and analysed for the percentage of flow voids in the para-atrophy zone (a 500 \u3bcm wide ring around the immediate edge of the atrophy) and in the peri-atrophy zone (a 500 \u3bcm wide ring around the para-atrophy zone edge), the latter considered as a reference in the comparative analysis. Results Thirty eyes of 20 patients were enrolled. The percentage of flow voids in the para-atrophy zone was 27.23%\ub16.29% and was significantly higher than in the surrounding peri-atrophy zone (23.4%\ub16.01%; p<0.001). There was no significant correlation between the flow void percentage in these regions and age, visual acuity, extent of the atrophic area or central choroidal thickness. Conclusions A significant impairment of the CC flow is present in the zone immediately surrounding the GA lesions strengthening the hypothesis that CC alterations may be relevant to the progression of GA

    The High Magnetic Field Phase Diagram of a Quasi-One Dimensional Metal

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    We present a unique high magnetic field phase of the quasi-one dimensional organic conductor (TMTSF)2_2ClO4_4. This phase, termed "Q-ClO4_4", is obtained by rapid thermal quenching to avoid ordering of the ClO4_4 anion. The magnetic field dependent phase of Q-ClO4_4 is distinctly different from that in the extensively studied annealed material. Q-ClO4_4 exhibits a spin density wave (SDW) transition at \approx 5 K which is strongly magnetic field dependent. This dependence is well described by the theoretical treatment of Bjelis and Maki. We show that Q-ClO4_4 provides a new B-T phase diagram in the hierarchy of low-dimensional organic metals (one-dimensional towards two-dimensional), and describe the temperature dependence of the of the quantum oscillations observed in the SDW phase.Comment: 10 pages, 4 figures, preprin

    de Haas-van Alphen Effect in the Two-Dimensional and the Quasi-Two-Dimensional Systems

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    We study the de Haas-van Alphen (dHvA) oscillation in two-dimensional and quasi-two-dimensional systems. We give a general formula of the dHvA oscillation in two-dimensional multi-band systems. By using this formula, the dHvA oscillation and its temperature-dependence for the two-band system are shown. By introducing the interlayer hopping tzt_z, we examine the crossover from the two-dimension, where the oscillation of the chemical potential plays an important role in the magnetization oscillation, to the three-dimension, where the oscillation of the chemical potential can be neglected as is well know as the Lifshitz and Kosevich formula. The crossover is seen at 4tz8tabH/ϕ04 t_z \sim 8 ta b H /\phi_0, where a and b are lattice constants, ϕ0\phi_0 is the flux quantum and 8t is the width of the total energy band. We also study the dHvA oscillation in quasi-two-dimensional magnetic breakdown systems. The quantum interference oscillations such as βα\beta-\alpha oscillation as well as the fundamental oscillations are suppressed by the interlayer hopping tzt_z, while the β+α\beta+\alpha oscillation gradually increases as tzt_z increases and it has a maximum at tz/t0.025t_z/t\approx 0.025. This interesting dependence on the dimensionality can be observed in the quasi-two-dimensional organic conductors with uniaxial pressure.Comment: 11 pages, 14 figure

    Fermi Surface Study of Quasi-Two-Dimensional Organic Conductors by Magnetooptical Measurements

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    Magnetooptical measurements of several quasi-two-dimensional (q2D) organic conductors, which have simple Fermi surface structure, have been performed by using a cavity perturbation technique. Despite of the simple Fermi surface structure, magnetooptical resonance results show a dramatic difference for each sample. Cyclotron resonances (CR) were observed for q-(BEDT-TTF)2I3 and (BEDT-TTF)3Br(pBIB), while periodic orbit resonances (POR) were observed for (BEDT-TTF)2Br(DIA) and (BEDT-TTF)3Cl(DFBIB). The selection of the resonance seems to correspond with the skin depth for each sample. The effective mass of POR seems to have a mass enhancement due to the many-body effect, while effective mass of CR is independent of the strength of the electron-electron interaction. The scattering time deduced from each resonance's linewidth will be also presented.Comment: 10 pages, 8 figures, to be published to J. Phys. Soc. Jpn Vol.72 No.1 (accepted
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