Journal of Mathematical and Fundamental Sciences
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Mafic and Ultramafic Rock Association in the East Arc of Sulawesi
No full textBusur Timur Sulawesi, yang terdiri dari Sulawesi Timur dan Tenggara, sebagian besar ditempati oleh suatu komplek luas terdiri dari kelompok batuan ultramafic yang diperkirakan berumur Mososoik hingga Tersier Bawah. Batuan-batuan tersebut dijumpai bersama dengan instrusi-intrusi batuan beku yang bersusunan gabro. Komplek batuan ultramafik ini merupakan suatu lajur yang terputus-putus, dan dapat diikuti dari bagian paling timur dari Sulawesi Timur ke arah barat dan membelok mengikuti arah struktur Sulawesi Tenggara. Komplek ini terdiri dari berbagai batuan ultramafic terutama harsburgit dan lersolit, serta dunit & piroksenit. Sebagian besar daerah yang diselidiki terdiri dari batuan-batuan ultramafic yang mengalami berbagai derajat serpentinisasi. Di beberapa bagian komplek ini, batuan-batuan ultramafic menunjukkan adanya korok-korok dan intrusi-intrusi kecil yang bersusunan gabro serta diorit. Asosiasi batuan tersebut dicirikan pula oleh bentuk dan penyebaran yang tidak teratur. Maksud dari pada tulisan ini adalah untuk mengemukakan data baru mengenai petrologi dan tektonik dari asosiasi batuan-batuan basa dan ultramafic ditinjau dari perkembangan teori dewasa ini. Penyelidikan yang bersifat pendahuluan ini didasarkan pada hasil analisa petrografi batuan, hubungan batuan-batuan satu sama lainnya di lapangan, serta pemetaan yang dilakukan selama berlangsungnya kegiatan explorasi geologi oleh P.T. International Nickel Indonesia. The East Arc (East and South-East Arms) of Sulawesi is largely occupied by a huge complex of ultramafic rocks of presumably late Mesozoic to early Tertiary age. The ultramafic rocks of Sulawesi are closely associated with small masses of gabbroic rocks. The ultramafic complex takes the form of discontinuous belts which can be traced from the eastern-most part of the Eastern Arm west-ward curving to the South-East following the Structural trend of the South-East Arm. The complex is made up chiefly of harzburgite, lherzolite, with some dunite and pyroxenite. Over most parts of the investigated area, these rocks have been serpentinized to variable degrees. Dikes and small intrusive bodies of gabbroic and dioritic composition have been encountered in many places within this belt. This rock assemblage is characterized by irregularity in form and distribution. The purpose of this paper is to bring up-to-date what is known on the petrology and tectonic setting of the mafic and ultramafic rocks in the light of new available data and current theories, the present preliminary study is mainly based upon petrographic data, and field relations obtained from recent geological exploration activities and mapping by P.T. International Niekel Indonesia.
Orientasi Kristal Tunggal Paduan Aluminium 6061
No full textIchtisar. Kawat-kawat kristal tunggal dari paduan Aluminium 6061 jang dihasilkan dengan tjara "strain-anneal", mempunjai orientasi kristal jang hampir sama dengan orientasi pengerdjaan dingin dari logam tersebut pada waktu pembuatan kawat.Abstract. Single crystal wires of 6061 Aluminium alloy, which are produced by "strain-anneal" method, nearly have the same orientation as the cold-work orientation of the wire.
Synthetic Medium for Growing Single Cells of Tobacco
Get PDF1. Studies were done to find out a synthetic defined medium for growing single cells of tobacco. Two kinds of media were tried for these purposes. With several changes in components, the revised medium of LINSMAIER & SKOOG (6) seemed to be good lot suspension and plating cultures of tobacco cells. The medium used by ERARLE & TORREY (3) for cells of Convolvulus also gave the desired results (table 1, plate 3).2. Growth of both callus and single cell cultures occurred on comparable kinetin concentrations.3. These studies (about the relationship between IAA and kinetin) gave no evidence of differentiation of the cell colonies within seven weeks after transferring the cells into the medium (plate 5).
A Photometric Study of the Galactic Cluster NGC 6124
Get PDFAbstract. Magnitudes and colours on the B, V system are determined for stars in the galactic cluster NGC 6124, based on a photoelectric sequence measured by Koelbloed and an extension of this toward faint stars. The distance of the cluster is about 580 pcs. and the age somewhat more than 108 years. Ichtisar. Magnitudo dan warna dalam sistim B. V daripada bintang2 dalam gugus galaktik NGC 6124 telah ditentukan berdasarkan suatu deret photoelektrik jang diukur oleh Koelbloed dan perluasannja kepada bintang-bintang jang lemah tjahanja. Djarak daripada gugus itu telah ditentukan kira2 580 pc. dan usianja kira2 108 tahun lebih sedikit
Photometry of the Galactic Cluster NGC 6649
Get PDFIchtisar. Dengan mengggunakan teknik fotoelektrik dan fotografik diberikanlah magnitudo dan warna daripada 80 bintang dalam gugus galaktik NGC 6649, dalam UBV Johnson. Dengan menggunakan reflektor 60 intji di Observatorium Boyden telah didapatkan observasi fotoelektrik dalam 3 warna. Untuk fotometri forografik telah diambil katja2 potret dalam 2 warna dengan menggunakan teleskop Schmidt 20-28 intji di Lembang. Modulus djarak visuil semu daripada NGC 6649 adalah 14,2 mag, ekses warnanja ialah 1,2 mag, dan modulus sesungguhnja ialah 10,6 mag., sesuai dengan djarak 1300 parsek. Observasi fotoelektrik membuktikan bahwa salah sebuah bintang dalam NGC 6649 mungkin adalah sebuah bintang berubah Cepheid Abstract. By using photoelectric and photographic techniques magnitudes and colours in the Jhonson UBC system are given for eighty stars in the galactic cluster NGC 6649. Photoelectric three-colour observations were made with the 60 inch reflector at the Boyden Observatory. Photographic plates taken in two colours with the 20-28 inch Scmidht type telescope at Lembang were used for photographic photometry. The apparent visual distance modulus of NGC 6649 is 14.2 mag., the colour excess is1.2 mag. and the true modulus, corresponding to a distance of 1300 parsecs. The photoelectric observation show that one of the stars in the cluster of NGC 6649 is a possible Cepheid variable.
Note on a Possible OB Association in Scorpius
No full textDuring a survey of Hα-emission stars, a clustering of OB and A-type stars was noticed in the constellation Scorpius. It is believed that these stars form a new association extending in R.A. from 17h00m to 17h16m (1900) and in Dec. from -31°30' to -34°30' (1900). The distance to this association is probably 1400 psc.In the course of recent survey of Hα-emission stars (1) in the vicinity of the emission nebulosities NGC 6334 and NGC 6357, the author noticed a clustering of Hα-emission stars to the north of dark nebula. This nebula is believed to form a connection between the two emission nebulae. The group of Hα-emission stars is centered about the Hα-emission stars HD 155806 (R.A.= 17h08.m7, Dec.=-33Ëš26';1900), which is classified as Oe5p in the Henry Draper extension, while in the Henry Draper Catalog it is classified as B3p.A total of 13 Hα-emission stars were found in circular area of 1,5 degree radius, centered on the star HD 155806. Two of these stars are of late spectral type, six are early spectral type, and the remaining five are too faint to classify on both red and blue plates. They might possibly be T-Tauri type star, as may also be the case for the faint Hα-emission stars which are seen projected on the dark nebulosity mentioned above.It is well known that T associations are sometimes found together with OB associations. In order to determine whether or not an OB associations exists together with the above mentioned possible T association, the author made a preliminary search for such an association in circular area of one degree radius centered on the star HD 155806. Chart No. 180 in the Henry Draper Extension was used for this survey. Within the prescribed area, 49 OB-Type and 85 A-type stars were found.The corresponding surface densities are thus 15.6 and 27.0 stars per square degre
The Laplace Transform of Vector-Valued Functions
Get PDFTeori klasik dari transformasi Laplace-Stieltjies, telah diperluas oleh E. Hille l4l untuk fungsi-fungsi pada [0,∞] ke dalam ruang Banach X jang mempunjai sifat bahwa setiap bilangan positip R, dengan supermum yang diambil terhadap semua koleksi-koleksi hingga {[rj, tj]}j=1 dari sub-interval2 lepas dari [0,R]. Setelah itu S.Zaidman (8) menyelediki hal jang serupa untuk fungsi-fungsi α jang bersifat kumpulan2 variasinya V ([0,R], α) jaitu koleksi semua elemen dari X jang berbentuk, merupakan sub kumpulan jang kompak di X.Karangan ini membitjarakan kemungkinan untuk membangun teori transformasi Laplace-Stieltjes untuk fungsi2 jang sifat2nja lebih umum daripada fungsi2 jang dipeladjari oleh Hille dan Zaidman. Ternjata bahwa banjak hukum2 jang berlaku untuk transformasi fungsi dengan harga scalar berlaku djuga di sini.Perhitungan absis konvergensi σc(α) dapat dikerdjakan serupa dengan perhitungan untuk fungsi2 berharga scalar (lihat [6]), dan begitu pula dengan hukum2 yang berhubungan dengan analistas berlaku di sini.Suatu hal yang menarik ialah bahwa rumus inversi, dengan a > max [0, σc(α)] tidak berlaku tanpa sjarat tambahan jang harus dipenuhi oleh fungsi α,Demikian Hille telah membuktikan bahwa rumus inversi di atas berlaku bila α mempunjai variasi jang terbatas absolute pada setiap interval jang hingga, sedangkan Zaidman mempergunakan sjarat tambahan bahwa pada variasi α pada setiap interval hingga adalah kompak.Ternjata bahwa kedua sjarat di atas dapat diperlunak mendjadi sjarat bahwa variasi α pada setiap interval jang hingga harus kompak dalam topologi lemah dari X.Lagipula, rumus inverse akan berlaku tanpa syarat untuk α , asal ruang X adalah lengkap-lemah, chususnya bila X refleksif. Hasil ini kami dasarkan atas karya Bartle, Dunford, dan Schwartz
Optimal Scheduling Policy for a Multi-upgraded Software System under Fuzzy Environment
Get PDFMany reliability growth models related to the concept of multi-upgrading have recently been proposed. This concept has helped software developers to develop a competitive edge over competitors by regularly introducing their software upgrades in the market at the optimal moment. The software reliability literature offers many different release-time policies, both under crisp and fuzzy environment. This paper presents a generic model of a multi-upgraded software system. The optimal scheduling policy for software under a fuzzy environment was determined. The proposed model was examined on a real-life failure data set of four software releases. The results obtained are encouraging
On Certain Aspect of Leaf Development in Aren (Arenga pinnata L)
No full textAbstract. In Arenga pinnata fold formation leading to the establishment of the future pinnae occurs by differential growth. During the development the abaxial ridges grow more rapidly than the axial ones resulting in a bending of the ridges to the adaxial side while the direction changes from horizontal, to oblique vertical. This leads to a crowding up of the adaxial ridges adaxial to the rachis. A covering or haut develops then extension growth of the nonplicate lamina over the adaxial ridges mentioned there by uniting them in a composite structure. The two parts fuse along the central meeting line, forming one continuous covering. The huge tubular ligule is initiated at the fourth or fifth primordium. At the 7th primordium the ligule encloses all younger leaf primordial. Its highest growth activity is reached about 2 primordia before the sword and the maximum size is held by the primordium before the latter. Penetration of the ligule by the sword initiates its disintegration in a basipetal direction, stops adaxial to the petiole base but proceeds at a slower pace ventrally.
