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INDONESIA
Jurnal Matematika & Sains
Published by Institut Teknologi Bandung
ISSN : -     EISSN : -     DOI : -
Core Subject : Education,
Mathematics
Arjuna Subject : -
Articles 339 Documents
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Penggunaan Enzim Selulase-Hemiselulase pada Proses Deinking Kertas Koran Bekas Jenni Rismijana; Iin Naomi Indriani; Tutus Pitriyani
Jurnal Matematika & Sains Vol 8, No 2 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

Deinking process of old newspaper by using cellulase-hemicellulase has been done. The old newspaper was beated, then at 4 % consistency, pH 5, and temperature 400 C, an enzyme was added with the dosage of 0,05-1,5 %. After reacting for 60 minutes the mixture was diluted and collector was added to catch the ink particles and then followed float for 20 minutes. The floating particle was scraped and the fibre was washed with fresh water until neutral pH and made as a sheet with 55 g/m2 grammage. A part of the fibre was bleached with peroxide before made as a sheet The optical and the physical properties including a dirt count, brightness, opacity, tensile index, tear index and elongation were tested. The experiment results showed the increase in the optical and the physical properties from the deinking sheet product. After bleaching process the optical properties increased, but the physical properties tended to decrease. The use of enzyme at 1% dosage gave the best result. The 0,05% enzyme dosage for the unbleached deiked pulp and 0,5% enzyme dosage for the bleached deiked pulp was able to fulfil the terms specification of newspaper according to SNI 14-0091-1998.
Magnetic, Mössbauer, and Electronic Spectral Properties of Bis(1,2,4-triazole)triazolatoiron(II) Trifluoromethanesulphonate Monohydrate Kristian H Sugiyarto
Jurnal Matematika & Sains Vol 8, No 2 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

Salt of [Fe(trzH)2(trz)][CF3SO3].H2O (where trzH = 1,2,4- triazole, and trz = triazolato, that is deprotonated 1,2,4-triazole anion) has been successfully isolated as white powder. Its magnetic, Mössbauer and electronic spectral properties are temperature dependent and reveal that the salt exhibits thermally spin state, singlet 1A1g ( .s)lquintet 5T2g (h.s), transition in iron(II). The transition is relatively abrupt, incomplete down to ~ 89 K and without hysteresis. The room-temperature electronic spectrum of the salt reveals a high-spin ligand field band which is split into two at about 11000 cm-1 and 13000 cm-1. At low temperature, the intensity of the high-spin ligand field band is reduced significantly and a strong low-spin ligand field band appears at about 18500 cm-1. The change in pattern of the spectrum is associated with the thermochromic behaviour, being white at room temperature but violet at the low one. The X-ray diffractogram suggests that the salt be isostructure to the corresponding hexafluorophosphate salt, [Fe(trzH)2(trz)][PF6], which is also white and high-spin at room temperature but pink-violet and low-spin at the low one.
Perubahan Bentuk pada Perambatan Signal Bi-kromatik dan Pengaruhnya terhadap Amplitudo Maksimum Marwan Marwan; Andonowati Andonowati
Jurnal Matematika & Sains Vol 8, No 2 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

We consider the signal propagation from a wave generation often simulated in hydrodynamic laboratories. As a particular case, we will study a deformation from the evolution of a bi-chromatic signal. The signal is a superposition of two mono-chromatics with different of frequencies. We use a KdV equation with exact dispersion as a model for uni-directional surface gravity waves. Using a direct expansion in the form of power series of the elevation signal amplitude gives a result to resonance in the third order. We correct this expansion using a modified Linstead-Poincare technique. From this, a non linear dispersion relating the wave number, amplitude and frequency can be derived. If the frequency different between the two mono-chromatics forming the bi-chromatics signal is small then the effect of third order side bands can dominate the second order terms. The coefficient of these terms contain an expression in the form of ()2/κqq. Deformations of bi-chromatic signal are significantly effected by this non linear dispersion as well as the side band terms. In this paper we will study the deformation of bi-chromatic signal propagation through the new approach called Maximal Temporal Amplitude (MTA).
The Birth Rate of Low-Mass X-Ray Binaries Winardi Sutantyo
Jurnal Matematika & Sains Vol 8, No 3 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

The evolutionary history and formation of low-mass X-ray binaries is considered. Various effects during their formation process are taken into account. Special emphasis is given to the common envelope evolution, the effect of an asymmetry in the supernova and the impact of the supernova shell on the companion star. Assuming a kick velocity between zero and 500 km s-1, the derived birthrate for low-mass X-ray binaries from the model computations is reconciable with estimated from the observed galactic population of O(100) and lifetime of O(108,7) yr if the common envelope efficiency is low (α CE ≤ 1,5). In this case, the derived birth rate depends only weakly on the kick velocity. Higher α CE results in a higher birthrate unless the kick velocity is also high (≥ 500 km s-1), which is incompatible with the observed mean velocity of pulsars. We conclude that the standard scenario produces a birthrate for low-mass X-ray binaries which is reconciable with the observations if α CE is low and this is valid for any kick velocity between zero and 500 km s-1.
Measurement of Sunspot Proper Motion Using Cross-Correlation Method Clara Yono Yatini; Soshinori Suematsu; Emanuel Sungging Mumpuni
Jurnal Matematika & Sains Vol 8, No 3 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

Cross-correlation method is a technique for determining the vector displacement that maximizes the spatially local cross-correlation between an image and a reference image as a continuous function of the image space. The crosscorrelation is defined as a function of position in the image, within a spatially localized apodization window. This method is applied to measure the proper motion of the sunspot accurately which can be calculated from a series of active region images as a function of time. This method gives a measure of the spot displacement unaffected by the jitter of the telescope.
Nonuniqueness Solution Forms of Close-Coupling Equations for e-He Scattering Agus Kartono; Toto Winata
Jurnal Matematika & Sains Vol 8, No 3 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

The close-coupling method relies on the reformulation of the Schrödinger equation into an infinite set of coupledchannel equations by expanding over the complete set of target states. The target states approach will be used is a restricted basis for helium states in which one of the electrons is in a fixed orbital (1s) while the second electron is described by a set of independent L2 functions, thus permitting it to span the discrete and continuum excitations. This type of approximate description of the target should be good for scattering problems in which the dominant reaction mechanism is by one-particle (electron) excitations. We will also show why the standard close-coupling expansion gives rise to nonunique solutions.
The Motion of Solar Wind Charged Particle in a Sinusoidal Vibrating Magnetic Field Iratius Radiman
Jurnal Matematika & Sains Vol 12, No 4 (2007)
Publisher : Institut Teknologi Bandung

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Abstract

The motion of solar wind charged particle in a small perturbed magnetic field lines of magnitude B1 is derived througha perturbed Lorentz force. By introducing a small sinusoidal velocity perturbation v1 in transverse direction to theoriginal velocity field vo, a small perturbed magnetic field is resulted from the original magnetic field of magnitude B0. Asystem of simultaneous differential equations describing the perturbed Lorentz force in Cartesian coordinates isobtained. These equations, denoted as RESY, are then treated numerically to follow qualitatively the behaviour of thecharge motion locally. The squared space velocity resulted from RESY are twice to three times larger than the initialvelocity squared in the case of constant magnetic field. Here the initial velocity was normalized to unity,whereas itsvalue may be estimated from the well-known Parker exponentially increased solar-wind velocity. Vibrating magneticfields might be one candidate to explain the observed very high velocities for some solar wind particles.
Pengaruh Bentuk dan Fluktuasi Ukuran Dot terhadap Pelebaran Garis Spektral Inhomogen pada Quantum Dot Gallium Nitrida (QD GaN) Fitri Suryani Arsyad; Budi Mulyanti; Amiruddin Supu; Moehamad Barmawi
Jurnal Matematika & Sains Vol 12, No 4 (2007)
Publisher : Institut Teknologi Bandung

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Abstract

Theoretical analysis of the phenomena of the size fluctuation in Gallium Nitride quantum dot (GaN QD) is presented inthis paper. The effect of QD size fluctuation on the electron and hole energy level and the inhomogeneous linebroadening is studied. Analytical expressions for the inhomogeneous line broadening are derived for a Gaussian sizefluctuation distribution. Decreasing in the QD carrier energy level is observed when QD size increases. The peak ofoptical transition energy probability (Emax) is shifted to higher energy when dot size fluctuation (σL) increases. Theoptical transition energy distribution (fE) of cylindrical QD is at the higher energy with the inhomogeneous linebroadening (σE) wider than those of conical, ellipsoidal, as well as semi ellipsoidal QD.
Spesiasi Senyawa Organotimah dengan Teknik Kromatografi Pasangan Ion-Fasa Terbalik Aman Sentosa Panggabean; Muhammad Bachri Amran; Buchari Buchari; Sadijah Achmad
Jurnal Matematika & Sains Vol 12, No 4 (2007)
Publisher : Institut Teknologi Bandung

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Abstract

The application of Ion Pair-Reversed Phase chromatography (IP-RP) technique for speciation of dibutyltin (DBT),tributyltin (TBT) and triphenyltin (TPhT) species has been studied. All of the species were able to separate on an ionpair-reversed phase chromatographic column. The eluats were detected online by the use of Hydride Generation-QuartzFurnace Atomic Absorption Spectrophotometry (HG-QFAAS) method. The eluent consisted of a mixture of methanol :water : acetic acid with a composition of 80:19:1, containing 1 mM of decane sulfonate as ion pairing reagent. The pHof the eluent was adjusted with 1 M H2SO4. The separation of all the species at the above conditions was good, whichwas shown by the values of the fundamental chromatographic parameters. The capacity factor (k) for DBT, TBT andTPhT species were 0.27, 2.54 and 5.92 respectively. The resolution (Rs) values for DBT-TBT and TBT-TPhT separationwere 2.92 and 2.42 respectively, while the selectivity for DBT-TBT and TBT-TPhT were 9.76 and 3.50, respectively.These data show the effectiveness of the developed chromatographic system.
Studi Pengaruh Rasio V/III terhadap Morfologi Permukaan Film Tipis GaSb yang Lilik Hasanah; Euis Sustini; Sukirno Sukirno; Maman Budiman
Jurnal Matematika & Sains Vol 8, No 3 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

Gallium Antimony (GaSb) thin film were grown on Semi Insulating (SI) GaAs (100) substrate by MOCVD (Metal-Organic Chemical Vapor Deposition) method. TMGa (trimethylgallium) and TDMASb (tridismethylaminoantimony) were used as precursors of group III and V, respectively, with H2 as gas carrier. The films were grown with V/III varied between 1,15 and 3,1. V/III ratio dependent of surface morphplogy and atomic composition of GaSb thin films were studied. The best surface morphology stoichiometric GaSb obtained at the V/II ratio of 2.0.

Page 17 of 34 | Total Record : 339

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