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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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A Method for Producing Bioethanol from the Lignocellulose of Shorea uliginosa Foxw. by Enzymatic Saccharification and Fermentation Wahyu Dwianto; F. Fitria; Ika Wahyuni; Danang Sudarwoko Adi; Sri Hartati; Rumi Kaida; Takahisa Hayashi
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 2 (2014)
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.2014.46.2.5

Abstract

Several papers have reported various technical aspects of lignocellulosic bioethanol production. Recalcitrance to saccharification is a major limitation for conversion of lignocellulosic biomass to ethanol. The biological process for converting lignocellulose to fuel ethanol includes delignification in order to liberate cellulose and hemicelluloses, depolymerization of carbohydrate polymers to produce free sugars, and sugar fermentation to produce ethanol. Access of plant cell wall polysaccharides to chemical, enzymatic and microbial digestion is limited by many factors, including the presence of lignin and hemicellulose that cover cellulose microfibrils. An effort to support the fuel ethanol fermentation industry using the Indonesian woody plant species Shorea uliginosa Foxw., was undertaken with regard to the established efficient bioethanol production process. This paper relates to a method for producing bioethanol from the lignocellulose of S. uliginosa Foxw. by saccharification and fermentation of xylem. A literature study of previous research on cellulose hydrolysis as a method for producing bioethanol was necessary. The objective of this study was to gain a deeper understanding of the degradation mechanisms of cellulose by enzymes through a study of previous research, which were then compared to the new method.
Effect of Furnish on Temperature and Vapor Pressure Behavior in the Center of Mat Panels during Hot Pressing Muhammad Navis Rofii; Noriko Yamamoto; Yoichi Kojima; Shigehiko Suzuki
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 2 (2014)
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.2014.46.2.6

Abstract

Particleboard achieves its overall performance characteristics during hot pressing process. As this process is influenced by several factors, particularly temperature and pressure, it is very important to understand the behavior of both. This study investigates the effects of furnish materials on temperature and vapor pressure behavior inside particleboard mat panels during hot pressing. Strand type particles from hinoki and ring-flaker recycled wood particles were used as furnish for laboratory-scale particleboard panels with a target density of 0.76 g/cm³. Mat panels with a moisture content of about 10% were hot pressed at a platen temperature of 180°C and an initial pressure of 3 MPa until the mat center reached the same temperature as the platen. A press monitoring device (PressMAN Lite) was used for detecting the temperature and vapor pressure change in the center of the mat panels. The study showed that the furnish type affected the temperature and vapor behavior inside the mat panels. Particleboard made of hinoki strand resulted in a longer plateau time, a higher plateau temperature and a higher gas pressure generated during hot pressing than those of ring-flaker recycled wood particles. Mixed board resulted in values between those of the two other furnish materials.
Modeling Haze Problems in the North of Thailand using Logistic Regression Busayamas Pimpunchat; Khwansiri Sirimangkhala; Suwannee Junyapoon
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 2 (2014)
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.2014.46.2.7

Abstract

At present, air pollution is a major problem in the upper northern region of Thailand. Air pollutants have an effect on human health, the economy and the traveling industry. The severity of this problem clearly appears every year during the dry season, from February to April. In particular it becomes very serious in March, especially in Chiang Mai province where smoke haze is a major issue. This study looked into related data from 2005-2010 covering eight principal parameters: PM10 (particulate matter with a diameter smaller than 10 micrometer), CO (carbon monoxide), NO2 (nitrogen dioxide), SO2 (sulphur dioxide), RH (relative humidity), NO (nitrogen oxide), pressure, and rainfall. Overall haze problem occurrence was calculated from a logistic regression model. Its dependence on the eight parameters stated above was determined for design conditions using the correlation coefficients with PM10. The proposed overall haze problem modeling can be used as a quantitative assessment criterion for supporting decision making to protect human health. This study proposed to predict haze problem occurrence in 2011. The agreement of the results from the mathematical model with actual measured PM10 concentration data from the Pollution Control Department was quite satisfactory.
Analysis of MaACS2, a stress-inducible ACC Synthase Gene in Musa acuminata AAA Group Cultivar Pisang Ambon Resnanti Utami Handayani; Fenny M. Dwivany
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 2 (2014)
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.2014.46.2.8

Abstract

Ethylene  has  an important function in plant growth and development. Ethylene  production  generally  increases  in  response  to  pathogen  attacks  and other  environmental  stress  conditions.  The  synthesis  of  this phytohormone  is regulated  by  two  enzymes,  ACC  synthase  (ACS)  and  ACC  oxidase  (ACO).  ACC synthase is encoded by a multigene  that  regulates  the  production  of ACC, after  which  this  precursor  is  converted  into  ethylene  by  ACO.  Pisang  Ambon (Musa  sp. AAA group), a banana cultivar originating from Indonesia, has nine ACS genes (MaACS  1-9) and one ACO gene (MaACO).  One  of  the  banana  ACS genes,  MaACS2,  is  stress-inducible.  In  this  research,  we  have  investigated  the expression  profile  of  MaACS2  in  the  roots  and  leaf  tissues  of  infected  tissue culture  plants.  Quantification  of  gene  expression  was analyzed using Real-Time PCR (qPCR) using  Ma18srRNA  and  MaGAPDH  as reference genes.  The results showed  nine-to  ten  fold  higher  MaACS2  expression  levels in  the  infected  roots tissues  compared to  the  uninfected roots  tissues. However,  MaACS2 expression in the leaves was only detected in infected tissue.
Optimal Control of Isometric Muscle Dynamics Robert Rockenfeller; Thomas Götz
Journal of Mathematical and Fundamental Sciences Vol. 47 No. 1 (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.2015.47.1.2

Abstract

We use an indirect optimal control approach to calculate the optimal neural stimulation needed to obtain measured isometric muscle forces. The neural stimulation of the nerve system is hereby considered to be a control function (input) of the system 'muscle' that solely determines the muscle force (output). We use a well-established muscle  model and experimental data of isometric contractions. The model consists of coupled activation and contraction dynamics described by ordinary differential equations. To validate our results, we perform a comparison with commercial optimal control software.
Bound State Solution of Dirac Equation for Generalized Pöschl-Teller plus Trigomometric Pöschl-Teller Non- Central Potential Using SUSY Quantum Mechanics S. Suparmi; C. Cari
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 3 (2014)
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.2014.46.3.1

Abstract

The bound state solution of the Dirac equation for generalized Pöschl-Teller and trigonometric Pöschl-Teller non-central potentials was obtained usingSUSY quantum mechanics and the idea of shape invariance potential. Theapproximate relativistic energy spectrum was expressed in the closed form. Theradial and polar wave functions were obtained using raising and lowering ofradial and polar operators. The orbital quantum numbers were found from thepolar Dirac equation, which was solved using SUSY quantum mechanics and theidea of shape invariance.
Antibacterial Curcuma xanthorrhiza Extract and Fractions Hartiwi Diastuti; Yana M. Syah; Lia D. Juliawaty; Marlia Singgih
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 3 (2014)
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.2014.46.3.2

Abstract

An acetone extract of Curcuma xanthorrhiza rhizomes and the n-hexane and chloroform fractions obtained from it were tested on eight pathogenic bacteria. The results showed that the acetone extract and the nhexane fraction exhibited significant activities against Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus, and weak activities against Shigella dysenteriae and Vibrio cholerae. They were inactive against Escherichia coli, Enterobacter aerogenes and Salmonella thypi, while the chloroform fraction was devoid of activities. NMR analysis disclosed the presence of α-curcumene, xanthorrhizol and an unknown monoterpene in the nhexane fraction. In the chloroform fraction, curcumin was found to be the main compound, together with xanthorrhizol as a minor compound. These results suggest that the antibacterial potency of acetone extract of C. xanthorrhiza is contained in the n-hexane fraction, in which the active constituents are terpenoid compounds. This is the first report of the use of NMR analysis for compound identification contained in an extract or fractions of C. xanthorrhiza.
Litsea cubeba Essential Oil Yield Harvested from Different Habitat Types on Mt. Papandayan, West Java, Indonesia Ichsan Suwandhi; Cecep Kusmana; Ani Suryani; Tatang Tiryana
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 3 (2014)
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.2014.46.3.5

Abstract

The objective of this research was to determine the yield and chemical composition of Litsea cubeba essential oil harvested from different habitat types on Mount Papandayan, West Java, Indonesia. The methods used were determination of sample plots at each habitat, followed by laboratory testing. Leaf samples were taken from each plot, the oil was extracted in the laboratory using steam distillation, which was subsequently analyzed by GC-MS. The results showed that the yield of essential oil was high (2.76-9.33%). The three dominant chemical compounds found were eucalyptol (16.97-55.78%), α-terpinenyl acetate (7.27-20.44%), and sabinene (14.45-68.05%). The results confirmed the expectation that Litsea cubeba essential oils extracted from Litsea cubeba trees growing in various habitats on Mount Papandayan would show a variety in yield and chemical composition.
A Study of Multiple Scattering in BGO and LYSO Single Crystal Scintillators Kittipong Seingsanor; Pruittipol Limkitjaroenporn; Jakrapong Kaewkhao
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.2016.48.2.5

Abstract

The angular distribution of multiple Compton scatterings from BGO and LYSO single crystal scintillators was studied at various scattering angles. Gamma photons with 662 keV energy, acquired from a 137Cs source, were used. The scattered photons were detected by a 51mm × 51mm NaI(Tl) scintillation detector. The overall energy correlated to the total number of scattered incidents was analytically reconstructed. The research found that the multiply scattered incidents had the same energy as received from the singly scattered distribution, as the attribution of multiply scattered incidents near the 90° scattering angle revealed. The research results were in agreement with the theoretical calculations.
Pb-free Radiation Shielding Glass Using Coal Fly Ash Watcharin Rachniyom; Suparat Tuscharoen; Jakrapong Kaewkhao; Pumipat Pachana
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.2015.47.3.8

Abstract

In this work, Pb-free shielding glass samples were prepared by themelt quenching technique using subbituminous fly ash (SFA) composed ofxBi2O3 : (60-x)B2O3 : 10Na2O : 30SFA (where x = 10, 15, 20, 25, 30 and 35 by wt%). The samples were investigated for their physical and radiation shielding properties. The density and hardness were measured. The results showed that the density increased with the increase of Bi2O3 content. The highest value of hardness was observed for glass sample with 30 wt% of Bi2O3 concentration. The samples were investigated under 662 keV gamma ray and the results were compared with theoretical calculations. The values of the mass attenuation coefficient (μm), the atomic cross section (σe) and the effective atomic number (Zeff) were found to increase with an increase of the Bi2O3 concentration and were in good agreement with the theoretical calculations. The best results for the half-value layer (HVL) were observed in the sample with 35 wt% of Bi2O3 concentration, better than the values of barite concrete. These results demonstrate the viability of using coal fly ash waste for radiation shielding glass without PbO in the glass matrices.

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