M. Barmawi
Laboratory of Electronic Material Physics (LEMP), Institut Teknologi Bandung

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Aplikasi Metoda Elemen Hingga Dengan Algoritma Crank-Nicolson Dalam Penyelesaian Persamaan Difusi Panas Untuk Pembuatan Sel Surya Silikon Amorf (a-Si) Terpadu Ridwan Abdullah Sani; M. Barmawi; Toto Winata; Sukirno Sukirno
Jurnal Matematika & Sains Vol 1, No 1 (1996)
Publisher : Institut Teknologi Bandung

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The solution of thermal diffusion equation computed numerically by finite element method is used to determine optimum conditions of laser irradiations in the solar cell fabrication. Structure discretization is analyzed in axisymmetric triangular ring elements. The program are codes in written using Fortran 77 language. The Crank-Nicolson algorithm and Fortran 77 IMSL library were used in solving stiffnen matrix equations of the structure. The convergence of the results are shown 50, 98, and 140 elements. The temperature distribution of at the center of laser beam in the all three layers of a-Si solar cells is also shown and superior compared with that of Kishi et al [19].
Simulation of Direct Laser Writing of YBa2Cu3O7-x/SrTiO3/MgO Structure for Fabrication of Josephson Junction R. A. Sani; E. H. Sujiono; T. Winata; M. Barmawi
Jurnal Matematika & Sains Vol 6, No 1 (2001)
Publisher : Institut Teknologi Bandung

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Fabrication of Josephson junction devices could be easily carried out using direct laser writing techniques. Thin film superconductor can be etched by melting it using a focused laser beam. While the laser beam is fixed, the etching pattern can be generated by moving the thin film on an X-Y table, which could be controlled by a computer. The melting radius is determined by the laser power density and the scanning-speed. The optimized scanning speed for fixed power density is predicted by solving the heat equation using finite element method. We consider a structure consisting of MgO substrate, a bufferlayer SrTiO3 and the superconducting YBCO film. The simulation is carried out for laser power of 1 to 5 watt at the wavelength of 514 nm.
REGENERASI IN VITRO KEDELAI MELALUI ORGANOGENESIS PADA TIGA KONSENTRASI BENZILADENIN Marveldani Marveldani; M. Barmawi; S. D. Utomo
Agrin Vol 11, No 2 (2007): Agrin
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.agrin.2007.11.2.67

Abstract

Penelitian ini bertujuan mengevaluasi kemampuan regenerasi eksplan buku kotiledon tiga varietaskedelai pada tiga konsentrasi benziladenin. Penelitian dilakukan di Laboratorium Kultur Jaringan FakultasPertanian Universitas Lampung, mulai bulan Januari sampai Agustus 2006. Perlakuan disusun dalamrancangan kelompok teracak sempurna yang terdiri dari 7 ulangan. Perlakuan merupakan kombinasi antaravarietas kedelai (Sinabung, Ijen, Anjasmoro) dan konsentrasi BA (0,75; 1,5; 2,25 mg/l). Eksplan berasal daribenih masak yang dikecambahkan secara in vitro selama 7-10 hari. Kecambah dipisahkan dari akarnyadengan cara memotong horizontal hipokotil 3-5 mm di bawah buku kotiledon. Selanjutnya kecambahdibelah vertikal di antara dua kotiledon sehingga diperoleh dua eksplan buku kotiledon. Pucuk poros embriodi atas buku kotiledon dibuang. Terakhir, dibuat 7-12 goresan sepanjang 3-4 mm sejajar dengan porosembrio pada buku kotiledon menggunakan pisau skalpel no. 15. Eksplan dikulturkan pada media MS yangditambahkan BA sesuai perlakuan percobaan. Hasil penelitian menunjukkan konsentrasi BA optimum untukregenerasi ketiga varietas kedelai adalah 0,75 mg/l media. Persentase eksplan membentuk tunas tertinggiditunjukkan oleh varietas Ijen yaitu sebesar 77,5% dan rata-rata jumlah tunas per eksplan tertinggiditunjukkan oleh varietas Sinabung yaitu sebanyak 5 tunas per eksplan.Kata kunci: Kedelai, benziladenin, regenerasi in vitro, organogenesis ABSTRACTThe objective of this study was to evaluate regenerating capability of three soybean varieties in threeconcentrations of BA. The study was conducted in Laboratory of Plant Tissue Culture, University ofLampung, from January to August 2006. The experiment was arranged in a randomized block design with 7replications. The treatment consisted of 2 factors, i.e., varieties (Anjasmoro, Ijen, and Sinabung) and theconcentration of benzyladenine (0.75, 1.5, and 2.25 mg/l BA). Cotyledonary-node explants were preparedfrom in vitro germinated mature seeds for 7-10 days. Seven to twelve 0.5 mm-deep slices were made on thejunction between hypocotyl and cotyledon of an explant. The explants were cultured on shoot initiationmedia containing MS salts amended with BA. The result indicated that optimum concentration of BA for invitro regeneration of the three varieties was 0.75 mg/l. The highest percentage of explants producing shootswas indicated by Ijen (77.5%). The highest average number of shoot per explant was indicated by Sinabung(5 shoots per explant).Key words: Benzyladenine, in vitro regeneration, organogenesis