4,219 research outputs found

    Perancangan Galeri Klub Sepakbola Arema Di Malang Dengan Metode Programatik Dan Semantik

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    Perkembangan sepakbola kian tahun makin berubah menjadi sebuah pertunjukan yang menghibur masyarakat umum. Saat ini, sepakbola dapat masuk ke setiap sisi sosial masyarakat mulai dari sosial tingkat bawah sampai tingkat atas. Karena begitu popular, olahraga sepak bola kini berkembang menjadi sebuah industri olahraga yang bertujuan komersial. Seperti yang telah diatur dalam Peraturan Mendagri, bahwa dana hibah APBD tidak dapat dialirkan langsung ke klub sepak bola di Indonesia. Sumber pendapatan klub yang dapat diperoleh dari luar klub adalah hak siar televisi, investor (football trust), dan sponsor. Sedangkan sumber dana yang berasal dari dalam klub sendiri yaitu penjualan tiket, merchandise, suporter, makanan dan supermarket. Saat ini belum ada pemusatan bisnis (industrialisasi) yang dilakukan oleh Arema sebagai klub professional. Galeri sebagai pusat income internal dari klub sepakbola Arema yang akan dirancang sesuai dengan permasalahan yang ada dengan memusatkan beberapa aspek pendapatan internal klub Arema. Perancangan Galeri Klub Sepakbola Arema di Malang ini menggunakan metode programatik, yaitu metode analisis terhadap data-data yang ada untuk menghasilkan sintesa atau keputusan, yaitu konsep perencanaan (planning). Konsep perencanaan tersebut menjadi bahan utama yang akan ditransformasi secara skematik menjadi konsep perancangan (designing). Metode yang akan diterapkan adalah Semantik Referensi dan Semantik Ekspresi untuk merancang tampilan bangunan yang mengidentitaskan (bermakna) persepakbolaan

    A Statistical Study on Force-Freeness of Solar Magnetic Fields in the Photosphere

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    It is an indisputable fact that solar magnetic fields are force-free in the corona, where force free fields means that current and magnetic fields are parallel and there is no Lorentz force in the fields. While the force-free extent of photospheric magnetic fields remains open. In this paper, the statistical results about it is given. The vector magnetograms (namely, BxB_{x}, ByB_{y} and BzB_{z} in heliocentric coordinates) are employed, which are deduced and calibrated from Stokes spectra, observed by Solar Magnetic Field Telescope (SMFT) at Huairou Solar Observing Station (HSOS) are used. We study and calibrated 925 magnetograms calibrated by two sets of calibration coefficients, that indicate the relations between magnetic fields and the strength of Stokes spectrum and can be calculated either theoretically or empirically. The statistical results show that the majority of active region magnetic fields are not consistent with the force-free model.Comment: 10 pages, 5 figures, has been accepted by PAS

    Study of Gamma Ray Attenuation of High-Density Bismuth Silicate Glass for Shielding Applications

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    ABSTRACT High density glass samples with a chemical formula of xBi 2 O 3 -30SiO 2 -10B 2 O 3 -20BaO-(40−x)ZnO (where x= 0, 10, 20, 30, and 40 mol %) were prepared using the melt-quenching technique in order to design a new transparently shielding materials for many fields of applications. The amorphous state of the samples was examined using X-ray diffraction technique at room temperature. The effect of bismuth on the structural properties of the studied glasses was characterized through density and its derivative parameters. Before measuring the attenuation capability, the optical transparently for visible light were tested using the transmittance spectra measurements in the UV-Visible region. Optical parameters such as optical band gap, Urbach energy, and refractive index were evaluated from the optical data. The Gamma ray attenuation coefficients of the glass samples were performed at gamma ray energies 238.63, 338.28, 583.19, 911.20, 968.97, 1173.23, 1332.49, and 2614.51 Co radioactive sources. The transmitted gamma rays were detected using Hyper Pure Germanium detector (HPGe) under good geometry conditions. The Linear attenuation coefficients were deduced from the attenuation curves and then the mass attenuation coefficients and the half value layer were estimated. Theoretical mass attenuation coefficients were calculated using WinXCom program (version 3.1). A good correlation was observed between the experimentally determined and those computed theoretically of the mass attenuation coefficients

    Coherent Pair State of Pion in Constituent Quark Model

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    A coherent state of pions is introduced to the nonrelativistic quark model. The coherent pair approximation is employed for the pion field in order to maintain the spin-isospin symmetry. In this approximation the pion is localized in the momentum space, and the vertex form factor in the pion-quark interaction is derived from this localization. The nucleon masses and wave functions are calculated using this model, and our results are compared to those of the quark model with the one pion exchange potential. Similar result is obtained for the mass spectrum, but there exists a clear difference in the internal structure of nucleon resonances.Comment: 17 pages, 2 figures, revtex, submitted to Phys. Rev.

    Magnetically Driven Warping, Precession and Resonances in Accretion Disks

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    The inner region of the accretion disk onto a rotating magnetized central star (neutron star, white dwarf or T Tauri star) is subjected to magnetic torques which induce warping and precession of the disk. The origin of these torques lies in the interaction between the (induced) surface current on the disk and the horizontal magnetic field (parallel to the disk) produced by the inclined magnetic dipole. Under quite general conditions, there exists a magnetic warping instability in which the magnetic torque drives the disk plane away from the equatorial plane of the star toward a state where the disk normal vector is perpendicular to the spin axis. Viscous stress tends to suppress the warping instability at large radii, but the magnetic torque always dominates as the disk approaches the magnetosphere boundary. The magnetic torque also drives the tilted inner disk into retrograde precession around the stellar spin axis. Moreover, resonant magnetic forcing on the disk can occur which may affect the dynamics of the disk. The magnetically driven warping instability and precession may be related to a number observational puzzles, including: (1) Spin evolution (torque reversal) of accreting X-ray pulsars; (2) Quasi-periodic oscillations in low-mass X-ray binaries; (3) Super-orbital periods in X-ray binaries; (4) Photometric period variations of T Tauri stars.Comment: 39 pages including 1 ps figure; Published version; ApJ, 524, 1030-1047 (1999

    A new variational approach to the stability of gravitational systems

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    We consider the three dimensional gravitational Vlasov Poisson system which describes the mechanical state of a stellar system subject to its own gravity. A well-known conjecture in astrophysics is that the steady state solutions which are nonincreasing functions of their microscopic energy are nonlinearly stable by the flow. This was proved at the linear level by several authors based on the pioneering work by Antonov in 1961. Since then, standard variational techniques based on concentration compactness methods as introduced by P.-L. Lions in 1983 have led to the nonlinear stability of subclasses of stationary solutions of ground state type. In this paper, inspired by pioneering works from the physics litterature (Lynden-Bell 94, Wiechen-Ziegler-Schindler MNRAS 88, Aly MNRAS 89), we use the monotonicity of the Hamiltonian under generalized symmetric rearrangement transformations to prove that non increasing steady solutions are local minimizer of the Hamiltonian under equimeasurable constraints, and extract compactness from suitable minimizing sequences. This implies the nonlinear stability of nonincreasing anisotropic steady states under radially symmetric perturbations

    Magnetospheric Accretion and Ejection of Matter in Resistive Magnetohydrodynamic Simulations

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    The ejection of matter in the close vicinity of a young stellar object is investigated, treating the accretion disk as a gravitationally bound reservoir of matter. By solving the resistive MHD equations in 2D axisymmetry using our version of the Zeus-3D code with newly implemented resistivity, we study the effect of magnetic diffusivity in the magnetospheric accretion-ejection mechanism. Physical resistivity was included in the whole computational domain so that reconnection is enabled by the physical as well as the numerical resistivity. We show, for the first time, that quasi-stationary fast ejecta of matter, which we call {\em micro-ejections}, of small mass and angular momentum fluxes, can be launched from a purely resistive magnetosphere. They are produced by a combination of pressure gradient and magnetic forces, in presence of ongoing magnetic reconnection along the boundary layer between the star and the disk, where a current sheet is formed. Mass flux of micro-ejection increases with increasing magnetic field strength and stellar rotation rate, and is not dependent on the disk to corona density ratio and amount of resistivity.Comment: 18 pages, many revisions from previous version, accepted in Ap

    Thin accretion disc with a corona in a central magnetic field

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    We study the steady-state structure of an accretion disc with a corona surrounding a central, rotating, magnetized star. We assume that the magneto-rotational instability is the dominant mechanism of angular momentum transport inside the disc and is responsible for producing magnetic tubes above the disc. In our model, a fraction of the dissipated energy inside the disc is transported to the corona via these magnetic tubes. This energy exchange from the disc to the corona which depends on the disc physical properties is modified because of the magnetic interaction between the stellar magnetic field and the accretion disc. According to our fully analytical solutions for such a system, the existence of a corona not only increases the surface density but reduces the temperature of the accretion disc. Also, the presence of a corona enhances the ratio of gas pressure to the total pressure. Our solutions show that when the strength of the magnetic field of the central neutron star is large or the star is rotating fast enough, profiles of the physical variables of the disc significantly modify due to the existence of a corona.Comment: Accepted for publication in Astrophysics & Space Scienc

    Development of Mouse Hepatocyte Lines Permissive for Hepatitis C Virus (HCV)

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    The lack of a suitable small animal model for the analysis of hepatitis C virus (HCV) infection has hampered elucidation of the HCV life cycle and the development of both protective and therapeutic strategies against HCV infection. Human and mouse harbor a comparable system for antiviral type I interferon (IFN) induction and amplification, which regulates viral infection and replication. Using hepatocytes from knockout (ko) mice, we determined the critical step of the IFN-inducing/amplification pathways regulating HCV replication in mouse. The results infer that interferon-beta promoter stimulator (IPS-1) or interferon A receptor (IFNAR) were a crucial barrier to HCV replication in mouse hepatocytes. Although both IFNARko and IPS-1ko hepatocytes showed a reduced induction of type I interferons in response to viral infection, only IPS-1-/- cells circumvented cell death from HCV cytopathic effect and significantly improved J6JFH1 replication, suggesting IPS-1 to be a key player regulating HCV replication in mouse hepatocytes. We then established mouse hepatocyte lines lacking IPS-1 or IFNAR through immortalization with SV40T antigen. Expression of human (h)CD81 on these hepatocyte lines rendered both lines HCVcc-permissive. We also found that the chimeric J6JFH1 construct, having the structure region from J6 isolate enhanced HCV replication in mouse hepatocytes rather than the full length original JFH1 construct, a new finding that suggests the possible role of the HCV structural region in HCV replication. This is the first report on the entry and replication of HCV infectious particles in mouse hepatocytes. These mouse hepatocyte lines will facilitate establishing a mouse HCV infection model with multifarious applications

    Formation of Millisecond Pulsars from Accretion Induced Collapse and Constraints on Pulsar Gamma Ray Burst Models

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    We study accretion induced collapse of magnetized white dwarfs as an origin of millisecond pulsars. We apply magnetized accretion disk models to the pre-collapse accreting magnetic white dwarfs and calculate the white dwarf spin evolution. If the pulsar magnetic field results solely from the flux-frozen fossil white dwarf field, a typical millisecond pulsar is born with a field strength ∌1011−1012G\sim 10^{11}-10^{12}G. The uncertainty in the field strength is mainly due to the uncertain physical parameters of the magnetized accretion disk models. A simple correlation between the pulsar spin Ω∗\Omega_* and the magnetic field B∗B_*, (Ω∗/104s−1)∌(B∗/1011G)−4/5(\Omega_*/10^4s^{-1})\sim (B_{*}/10^{11}G)^{-4/5}, is derived for a typical accretion rate \sim 5\times 10^{-8}M_{\sun}/yr. This correlation remains valid for a wide pre-collapse physical conditions unless the white dwarf spin and the binary orbit are synchronized prior to accretion induced collapse. We critically examine the possibility of spin-orbit synchronization in close binary systems. Using idealized homogeneous ellipsoid models, we compute the electromagnetic and gravitational wave emission from the millisecond pulsars and find that electromagnetic dipole emission remains nearly constant while millisecond pulsars may spin up rather than spin down as a result of gravitational wave emission. We also derive the physical conditions under which electromagnetic emission from millisecond pulsars formed by accretion induced collapse can be a source of cosmological gamma-ray bursts. We find that relativistic beaming of gamma-ray emission and precession of gamma-ray emitting jets are required unless the dipole magnetic field strengths are >1015>10^{15}G; such strong dipole fields are in excess of those allowed from the accretion induced collapse formation process except in spin-orbit synchronization.Comment: 36 pages, AASLATEX, 4 ps figures, Ap
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