698 research outputs found

    Intruder level and deformation in the SD-pair shell model

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    The influence of the intruder level on nuclear deformation is studied within the framework of the nucleon-pair shell model truncated to an SD-pair subspace. The results suggest that the intruder level has a tendency to soften the deformation and plays an important role in determining the onset of rotational behavior.Comment: 2 input TeX files, 2 figures, submitted to Phys. Lett.

    Pirolisis Kayu Ketapang (Terminalia Catappal) Menjadi Bio-Oil dengan Katalis Mo/Lempung Cengar

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    The demand for renewable energy to adequate human energy continue to increase. Currently, the main energy source in the world is a fossil fuel. So, we need alternative energy instead of petroleum. Biomass can be used as a bio-oil by pyrolysis. The wood can be used as raw materials of bio-oil is not a superior product and its rapid growth, these requirements exist in ketapang tree (Terminalia catappa L.).The purpose of this research is to make bio-oil from ketapang tree using a catalyst Mo/clay by pyrolysis process, as well as test physical properties of the bio-oil, and to determine the effect of variation the carrier of the catalyst metal catalyst weight variations against of biomass. In this research ketapang tree by the size of -100+200 mesh, 50 grams, 500 ml silinap and catalyst Mo / clay inserted into of pyrolysis reactor. This process conducted at a temperature 320oC and the stirring speed of 300 rpm operate for about 120 minutes by flowing nitrogen gas. For the optimum yields obtained at 1.5% catalyst Mo/clay as much as 7% of biomass that is equal to 70,35%. The test results physical properties obtained density of 1.005 g/ml, 2.14 cSt viscosity, acidity 46.17 mg NaOH /g sample and the flash point 49oC. Results of analysis compound chemical using GC-MS, obtained the dominant chemical components in the bio-oil is Methyl 2-Hydroxybutyrate (16,79%); Methyl acetate (5,66%); 1-hydroxy-,2-Propanone (12,96%) ; Acetic acid (31,53%)

    Shell model description of normal parity bands in odd-mass heavy deformed nuclei

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    The low-energy spectra and B(E2) electromagnetic transition strengths of 159Eu, 159Tb and 159Dy are described using the pseudo SU(3) model. Normal parity bands are built as linear combinations of SU(3) states, which are the direct product of SU(3) proton and neutron states with pseudo spin zero (for even number of nucleons) and pseudo spin 1/2 (for odd number of nucleons). Each of the many-particle states have a well-defined particle number and total angular momentum. The Hamiltonian includes spherical Nilsson single-particle energies, the quadrupole-quadrupole and pairing interactions, as well as three rotor terms which are diagonal in the SU(3) basis. The pseudo SU(3) model is shown to be a powerful tool to describe odd-mass heavy deformed nuclei.Comment: 11 pages, 2 figures, Accepted to be published in Phys. Rev.

    Relativistic Mean Field Approach and the Pseudo-Spin Symmetry

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    Based on the Relativistic Mean Field (RMF) approach the existence of the broken pseudo-spin symmetry is investigated. Both spherical RMF and constrained deformed RMF calculations are carried out employing realistic Lagrangian parameters for spherical and for deformed sample nuclei. The quasi - degenerate pseudo-spin doublets are confirmed to exist near the fermi surface for both spherical and deformed nuclei.Comment: 9 pages RevTex, 4 p.s figures, to appear in Phys. Rev. C as R.

    Symplectic No-core Shell-model Approach to Intermediate-mass Nuclei

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    We present a microscopic description of nuclei in an intermediate-mass region, including the proximity to the proton drip line, based on a no-core shell model with a schematic many-nucleon long-range interaction with no parameter adjustments. The outcome confirms the essential role played by the symplectic symmetry to inform the interaction and the winnowing of shell-model spaces. We show that it is imperative that model spaces be expanded well beyond the current limits up through fifteen major shells to accommodate particle excitations that appear critical to highly-deformed spatial structures and the convergence of associated observables.Comment: 9 pages, 8 figure

    Elliptic operators in odd subspaces

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    An elliptic theory is constructed for operators acting in subspaces defined via odd pseudodifferential projections. Subspaces of this type arise as Calderon subspaces for first order elliptic differential operators on manifolds with boundary, or as spectral subspaces for self-adjoint elliptic differential operators of odd order. Index formulas are obtained for operators in odd subspaces on closed manifolds and for general boundary value problems. We prove that the eta-invariant of operators of odd order on even-dimesional manifolds is a dyadic rational number.Comment: 27 page

    Analisis Peta Struktur Domain Waktu dalam Studi Pengembangan Lapangan Kaprasida, Cekungan Sumatera Tengah

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    Pengembangan lapangan migas masih sangat digencarkan, khususnya pada Lapangan “Kaprasida”. Pada lapangan ini dilakukan studi pengembangan terhadap reservoar sekunder, yaitu pada Formasi Transisi, Upper Menggala, dan Lower Menggala. Reservoar sekunder masih menyimpan beberapa struktur jebakan hidrokarbon yang perlu analisis lebih dalam. Oleh karena itu, pada lapangan ini dilakukan proses reinterpretasi terhadap patahan dan lapisan tersebut, sehingga menghasilkan peta struktur domain waktu. Maksud dari penelitian ini adalah untuk melakukan reinterpretasi yang menghasilkan peta struktur domain waktu, sehingga dapat melakukan analisis pada peta struktur. Setelah dilakukan analisis pada peta struktur domain waktu ketiga lapisan, didapatkan beberapa zona target berupa beberapa struktur antiklin. Zonasi struktur antiklin terdapat pada wilayah barat TG2, selatan TG2, timur TG2, barat TG4, dan utara TG1. Dari hasil penelitian ini diharapkan dapat memberikan struktur jebakan hidrokarbon baru untuk kegiatan pengembangan Lapangan “Kaprasida”
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