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Journal of Mathematical and Fundamental Sciences
Published by Institut Teknologi Bandung
ISSN : 23375760     EISSN : 23385510     DOI : https://doi.org/10.5614/j.math.fund.sci.
Core Subject : Science, Education,
Astronomy Chemistry Earth & Planetary Sciences Mathematics Physics
Journal of Mathematical and Fundamental Sciences welcomes full research articles in the area of Mathematics and Natural Sciences from the following subject areas: Astronomy, Chemistry, Earth Sciences (Geodesy, Geology, Geophysics, Oceanography, Meteorology), Life Sciences (Agriculture, Biochemistry, Biology, Health, Medical, Pharmacy), Mathematics, Physics, and Statistics.
Arjuna Subject : Matematika - Matematika (Lain-Lain)
Articles 689 Documents
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Site Response Characteristics of Simeulue Island, Indonesia as Inferred from H/V Spectral Ratio of Ambient Noise Records Titi Anggono; Syuhada Syuhada; Nugroho Dwi Hananto; Lina Handayani
Journal of Mathematical and Fundamental Sciences Vol. 48 No. 2 (2016)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2016.48.2.4

Abstract

Simeulue Island is an outer island arc off west of the Sumatra Island. The Island is located close to the interface of the subduction zone between Indo-Australian and Eurasian Plates. Seismic activities around the Island included devastating megathrust earthquakes, such as 2004 MW 9.2 Sumatra-Andaman and 2005 MW 8.7 Nias earthquakes. We investigate the site response characteristics using Horizontal-to-Vertical (H/V) Spectral Ratio method to the continuous ambient noise records from eight broadband seismometers. From the calculation, we generally observe strong peak of H/V spectral ratio which is caused by the strong impedance contrast at these area. However, sites BATU, LABU and DEHI show relatively flat H/V spectral ratio curves that caused by lack of sharp impedance contrast beneath the site. We also observe multiple peaks at several sites that may indicate the presence of a more highly weathered soil/clay layer on top of a more compact medium. H/V peak frequencies, which shows fundamental frequencies resonance of soil sites, generally are observed at range about 2.0 - 16.4 Hz. From the observed H/V spectral ratio, we suggest that the strong impedance contrasts may occur on the shallow part of the medium at 2 up to15 m depth.
Phosphate Solubilizing Bacteria Adaptive to Vinasse Kahar Muzakhar; Sutoyo Sutoyo; Ahmad Bukhari Saragih
Journal of Mathematical and Fundamental Sciences Vol. 47 No. 2 (2015)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2015.47.2.8

Abstract

Microorganisms identified as phosphate solubilizing bacteria (PSB) adaptive to vinasse were successfully screened from sugarcane soil from an agriculatural estate in Jatiroto. By conducting a screening on Pikovskaya's agar medium (PAM), we found that five different isolates were detected as PSB (pvk-5a, pvk-5b, pvk-6b, pvk-7a, and pvk-8a). Of the five isolates only three could be grown and were found to be adaptive to vinasse based medium without any nutrients added (pvk-5a, pvk-5b and pvk-7a). The three isolates were  characterized as coccus and Gram negative with no endospores detected. We suggest that these three isolates can be used as biofertilizer agent to  support organic farming.
Synthesis and Characterization of Bio-based Nanomaterials from Jabon (Anthocephalus cadamba (Roxb.) Miq) Wood Bark: an Organic Waste Material from Community Forest Sutrisno Sutrisno; Tati Suryati Syamsudin; Eka Mulya Alamsyah; Bambang Sunendar
Journal of Mathematical and Fundamental Sciences Vol. 47 No. 2 (2015)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2015.47.2.7

Abstract

The application of nanotechnology to produce nanomaterials from renewable bio-based materials, like wood bark, has great potential to benefit the wood processing industry. To support this issue, we investigated the production of bio-based nanomaterials using conventional balls milling. Jabon (Anthocephalus cadamba (Roxb.) Miq) wood bark (JWB), an organic waste material from a community forest was subjected to conventional balls milling for 96 h and was converted into bio-based nanomaterial. The morphology and particle size, chemical components, functional groups and crystallinity of the bio-based nanomaterial were evaluated using scanning electron microscopy (SEM), scanning electron microscopy extended with energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The particle-sizes obtained for the JWB bio-based nanomaterial were between 43 nm to 469 nm and the functional groups were detected as cellulose. The chemical components found were carbon, oxygen, chloride, potassium and calcium, except for the sample produced from sieve type T14, which did not contain chloride. The crystalline structure was calcium oxalate hydrate (C2CaO4.H2O) with crystalline sizes 21 nm and 15 nm, produced from sieve types T14 and T200 respectively.
In Vitro Regeneration of Foxtail Millet (Setaria italica (L.) Beauv.) cv. Buru Hotong Iriawati Iriawati; Melisa Puspita; Asep Rodiansyah
Journal of Mathematical and Fundamental Sciences Vol. 49 No. 2 (2017)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2017.49.2.6

Abstract

In vitro regeneration of foxtail millet (Setaria italica (L.) Beauv.) was done using basal shoot explants of 10-day old seedlings. Explants were cultured in MS basal medium supplemented with 2,4-dichlorophenoxyacetic acid  (2,4-D), kinetin, 6-benzylaminopurine (BAP) and 1.5 ppm NiSO4. Shoot multiplication and root induction were done in Murashige and Skoog (MS) basal media. Plantlets were then acclimatized in rice husk charcoal, cocopeat, or mixed media. Results showed that MS basal medium containing 0.5 ppm kinetin, 2 ppm BAP, and 0.1 ppm 2,4-D was the optimal medium for shoot induction, in which 60% of explants developed direct shoot organogenesis. In addition, callus was optimally formed in MS medium supplemented by 1 ppm kinetin, 1 ppm BAP, and 0.5 ppm 2,4-D. Regenerated shoots spontaneously developed roots after being transferred into MS basal media without growth regulator. During acclimatization, the highest survival rate of plantlets (47%) was obtained in rice husk charcoal. The developed method could be useful towards improvement of this species using in vitro tissue culture techniques.
Influence of Various Precursor Compositions and Substrate Angles on ZnO Nanorod Morphology Growth by Aqueous Solution Method Puenisara Limnonthakul; Daw Yangnoi; Patamas Bintachitt; Manoch Hengwattana; Mati Horprathum
Journal of Mathematical and Fundamental Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2016.48.1.5

Abstract

ZnO nanorods were synthesized on silicon wafer substrate with a seed zinc layer using the aqueous solution method. The influence of various precursor compositions on the morphology of the ZnO nanorods, with substrate angles at 0° and 90°, was investigated. The various ratios of hexamethylenetetramine in zinc nitrate hexahydrate were used as precursors in the synthesis of ZnO. Scanning electron micrography indicated that the growth of the ZnO nanorods with a 0° substrate angle was smaller than with a 90° substrate angle. The substrate angle is defined as the angle between the plane of the substrate and the horizontal layer of an aqueous solution. When the precursor concentration of hexamethylenetetramine is not equal to the ratio corresponding to the chemical reaction, the effect of the substrate angle on the diameter size and morphology of the ZnO nanorods is evident. Grazing incident X-ray diffraction (GIXRD) was used to characterize the structure of all samples. The diffraction patterns showed that the orientation matched the hexagonal wurtzite structure.
New Seven-Step Numerical Method for Direct Solution of Fourth Order Ordinary Differential Equations Zurni Omar; John Olusola Kuboye
Journal of Mathematical and Fundamental Sciences Vol. 48 No. 2 (2016)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2016.48.2.1

Abstract

A new numerical method for solving fourth order ordinary differential equations directly is proposed in this paper. Interpolation and collocation were employed in developing this method using seven steps. The use of the approximated power series as an interpolation equation was adopted in deriving the method. The basic properties of the new method such as zero-stability, consistency, convergence and order are established. The numerical results indicate that the new method gives better accuracy than the existing methods when it is applied to fourth ordinary differential equations.
Trees with Certain Locating-chromatic Number Dian Kastika Syofyan; Edy Tri Baskoro; Hilda Assiyatun
Journal of Mathematical and Fundamental Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2016.48.1.4

Abstract

The locating-chromatic number of a graph G can be defined as the cardinality of a minimum resolving partition of the vertex set V(G) such that all vertices have distinct coordinates with respect to this partition and every two adjacent vertices in G are not contained in the same partition class. In this case, the coordinate of a vertex v in G is expressed in terms of the distances of v to all partition classes. This concept is a special case of the graph partition dimension notion. Previous authors have characterized all graphs of order n with locating-chromatic number either n or n-1. They also proved that there exists a tree of order n, n≥5, having locating-chromatic number k if and only if k âˆˆ{3,4,"¦,n-2,n}. In this paper, we characterize all trees of order n with locating-chromatic number n - t, for any integers n and t, where n > t+3 and 2 ≤ t < n/2.
Approximate Solutions of Linearized Delay Differential Equations Arising from a Microbial Fermentation Process Using the Matrix Lambert Function Agus Yodi Gunawan; Kasbawati Kasbawati; Kuntjoro Adji Sidarto
Journal of Mathematical and Fundamental Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2016.48.1.3

Abstract

In this paper we present approximate solutions of linearized delay differential equations using the matrix Lambert function. The equations arise from a microbial fermentation process in a metabolic system. The delay term appears due to the existence of a rate-limiting step in the fermentation pathway. We find that approximate solutions can be written as a linear combination of the Lambert function solutions in all branches. Simulations are presented for three cases of the ratio of the rate of glucose supply to the maximum reaction rate of the enzyme that experienced delay. The simulations are worked out by taking the principal branch of the matrix Lambert function as the most dominant mode. Our present numerical results show that the zeroth mode approach is quite reliable compared to the results given by classical numerical simulations using the Runge-Kutta method.
Embryo Incision as a New Technique for Double Seedling Production of Indonesian Elite Coconut Type “Kopyor” Sisunandar Sisunandar; Alkhikmah Alkhikmah; Arief Husin; Aman Suyadi
Journal of Mathematical and Fundamental Sciences Vol. 47 No. 3 (2015)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2015.47.3.3

Abstract

One of the present major limitations of seedling production of kopyor type coconut using embryo culture is that only one seedling can be produced from a single embryo. Therefore, we report on the development of a new breakthrough technique for the production of double seedlings from a single embryo. The technique consists of four steps, viz. (i) germination; (ii) incision; (iii) splitting; and (iv) recovery. A histological study was carried out on the development of the halved embryo into a new shoot. The best recovery process was obtained when the incised embryo was split into two and recovered into Murashige and Skoog (MS) medium supplemented with 2 μM IBA and 15 μM kinetin. Following this protocol, an average of 56 shoots was successfully recovered from 30 zygotic embryos. The histological study also revealed that the meristem tissue of the halved embryo was able to produce a new meristem and primordial leaf. Most of the shoots then went on to produce normal seedlings and could be acclimatized successfully after having developed 2 or 3 leaves. This protocol is useful for routine seedling production of the kopyor-type coconut.
Effect of V Dopant on Physicochemical Properties of Vanadium-Doped Anatase Synthesized via Simple Reflux Technique Hari Sutrisno; Ariswan Ariswan; Dyah Purwaningsih
Journal of Mathematical and Fundamental Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2016.48.1.8

Abstract

Mesoporous pure TiO2 (M-TiO2) and mesoporous-vanadium-doped TiO2 (M-V-doped TiO2) were successfully synthesized via a facile and simple reflux technique. The purpose of this research was to study the effect of vanadium dopant on the physicochemical properties of all materials obtained. Characterization of the prepared materials was carried out using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and N2-adsorption-desorption analysis. The presence of Ti and O elements in M-TiO2 and of Ti, V and O elements in M-V doped TiO2 could be detected by SEM-EDS, while the patterns of X-ray diffraction of all the prepared samples had a well-crystalline surface of anatase type. All mesoporous vanadium-doped TiO2 (M-V-doped TiO2) materials performed in a highly transparent mode in the visible region at 554 nm (Eg = 2.24 eV) and 588 nm (Eg = 2.12 eV) for 3.3 and 4.9 wt% V doped TiO2, respectively. The Rietveld refinement method was applied to extract the structural parameters of the M-TiO2 and M-V-doped TiO2 using the Fullprof program in the WinPlotr package. The prepared materials were refined in the crystal system and space group of anatase (tetragonal, I41/amd (141)). The vanadium ion was successfully doped into TiO2. The isotherm type of M-TiO2 and 2.3 wt% V doped TiO2 were of type IV, with a profile of type H2 hysteresis loops, while the 3.3 and 4.9 wt% vanadium-doped TiO2 reflected isotherm type III. The Brunauer-Emmett-Teller (BET) results showed a significant reduction in surface area due to increased concentrations of vanadium. The highest values of BET-specific surface area, pore volume and average pore size of M-TiO2 were 46 m2/g, 18.45 nm and 0.2572 cm3/g respectively.

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