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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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Simulation of Ultra-Short Laser Pulses Propagation and Ionization in Dual-Gas-Cells to Enhance the Quasi-Phase Matching of Harmonics Generation in Plasmas Wameedh Adress
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.55.3.4

Abstract

A numerical model was designed and implemented to investigate the influence of plasma defocusing on laser characteristics. The effects of plasma defocusing were investigated by studying beam divergence, intensity reduction, and blue shifting. The diffusion of the ultra-intense laser beam in gas cells was within a Rayleigh range. Moreover, using dual-gas-cells, the impact of quasi-phase matching (QPM) on the creation of harmonic pulses in argon and hydrogen plasmas was studied. The alternating structure of argon and hydrogen gas cells showed a perfect build-up of the generated ultra-short harmonics pulses. The impact of electron density on laser diffusion and the creation of harmonic pulses were also investigated in this work. In the simulation, argon plasma with different plasma densities was used in an alternating structure to create dual-gas-cells and quasi-phase-matching. Noticeable conversion of the fundamental laser pulses to harmonics pulses was accomplished in the model by using the QPM concept.
Linear and Nonlinear Electro-optic Response of MHPOCBC Andika Fajar; Hiroshi Orihara
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.55.3.2

Abstract

This study investigated the linear and second-order electro-optic responses in chiral smectic liquid crystal 4-(1-methylheptyloxycarbonyl) phenyl 4-octylcarbonyloxybiphenyl-4-carboxylate (MHPOCBC). The result revealed a single Debye-type relaxation in the linear electro-optic frequency dispersion, with a relaxation frequency extending up to one hundred kHz. Conversely, the second-order electro-optic response exhibited intricate temperature-dependence, accurately depicted by a phenomenological Landau theory around the SmA–SmCa* phase transition point. Notably, in the SmCa* phase, critical slowing down of the amplitude mode occurred near the transition to the SmA phase, while at lower temperatures of the SmCa* phase, a distinct low-frequency relaxation mode emerged. Furthermore, the relaxation frequency of the antiferroelectric Goldstone mode in the SmCA* phase remained constant across the entire temperature range. These findings should significantly contribute to the understanding of dynamic behaviors in chiral smectic liquid crystals, shedding light on their complex phase transitions and electro-optic properties.
Study of the Effect of Physical Parameters on Commercial Hydroponics Based on Internet of Things (IoT): A Case Study of Bok Coy Plants (Brassica rapa) and Water Spinach (Ipomoea Aquatica) Maman Budiman; Efraim Partogi; Ant. Ardath Kristi; Prianka Anggara; Nina Siti Aminah
Journal of Mathematical and Fundamental Sciences Vol. 54 No. 2 (2022)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2022.54.2.5

Abstract

Population growth causes the demand for food to increase. One solution that can be applied is agriculture with hydroponic technology. To increase production efficiency, one must know the physical parameters that most influence the production process. This research used an IoT system to gather accurate and precise measurement data of physical parameters to be used as a dataset for machine learning. The dataset consisted of light intensity, humidity, air temperature, and total dissolved solids (TDS). Plant growth was measured by leaf area of the plant, number of leaves, and plant stem length every 3 to 4 days. The models used in the machine learning process were linear regression, polynomial regression, and random forest regression. The machine learning results showed that the best model for predicting plant growth was random forest regression with an MAE of 8.3% and an R2 of 0.93, for both bok coy and water spinach. The variables that influence growth the most are TDS and light intensity. According to the relationship between TDS gradient and plant growth gradient, the most optimal growth can be achieved by raising the TDS gradient or by maintaining a high TDS, which can be achieved by adding nutrient solution to the tank regularly.
Synthesis, Structure, Magnetic and Antibacterial Properties of polymeric [M(Quin)2(N(CN)2)2]∞ (M = Mn(II), Co(II); Quin = quinoline) I Wayan Dasna; Ubed Sonai Fahruddin Arrozi; Husni Wahyu Wijaya; Sutandyo Dwija Laksmana; Stéphane Golhen
Journal of Mathematical and Fundamental Sciences Vol. 54 No. 2 (2022)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2022.54.2.4

Abstract

Two complexes of [Mn(Quin)2(N(CN)2)2]∞ (1) and [Co(Quin)2(N(CN)2)2]∞ (2) were synthesized and characterized. The as-synthesized complexes crystallized in a triclinic lattice with a space group of P-1. The unit cell parameter of 1 was a = 7.5207(14) Å, b = 7.7729(16) Å, c = 9.5968(15) Å, α = 96.388(6) o, β = 112.617(5) o, γ = 102.751(6) o, while for complex 2 it was a = 7.3942(10) Å, b = 7.7960(10) Å, c = 9.4907(13) Å, α = 96.631(4) o, β = 112.742(4) o, γ = 102.458(4) o. The magnetic properties and antimicrobial properties of both polymeric complexes were examined by magnetic susceptibility and diffusion techniques, respectively. Complexes 1 and 2 both showed antiferromagnetic properties and had a higher inhibitory effect on the growth of Staphylococcus aureus than Salmonella typhi.
Conditioned Medium of IGF1-Induced Human Wharton’s Jelly Mesenchymal Stem Cells Effects on Sox9 Gene Expression and Level of COL2 and IL1β in Osteoarthritic Chondrocytes Widowati, Wahyu; Kusuma, Hanna Sari Widya; Azis, Rizal; Eltania, The Fransiska; Nindya, Faradhina Salfa
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.56.3.1

Abstract

Wharton’s jelly mesenchymal stem cells (WJMSCs) hold promises for treating osteoarthritis (OA) due to their great capacity for regeneration and their accessibility. However, obstacles like poor cell survival and differentiation prevent them from being used in transplants. Thus, this study examined WJMSCs’ Conditioned Medium (CM) (WJMSCs-CM) for OA treatment. In order to determine how well IL1β-induced chondrocyte cells (IL1β-CHON002) heal OA-damaged cells, they were treated with both IGF1-induced and uninduced WJMSCs-CM. Key parameters measured were IL1β, Sox9 and COL2. The STRING database was explored to evaluate the proteins contained in WJMSCs-CM and to see their interactions and CM potential in OA exposure. The STRING database indicates WJMSCs-CM to possess the ability to manage OA because of the growth factors they contain, which raise the expression of cartilage marker genes. The results indicated that 15% WJMSCs-CM with 150 ng/mL IGF1 had the highest Sox9 expression, significant reduction in pro-inflammatory mediators, and an increase in COL2 levels. Additionally, 14 days of treatment resulted in better outcomes compared to 7 days. CM from WJMSCs treated with IGF1 with a concentration of 15% exhibited the highest level for each parameter. Both durations showed difference across parameters, highlighting the potential for OA therapy.
Density Functional Theory Investigation on Muon Hyperfine Interaction in Methylated Guanine-Cytosine Double-Strand DNA Jamaludin, Ammaina; Sulaiman, Shukri; Zaharim, Wan Nuradhilah; Lee Sin, Ang
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.56.3.2

Abstract

The aims of this study were to determine the most likely Mu trapping sites based on total energy consideration as well as identifying the associated muon hyperfine coupling constant of 1, 2, and 3 methylated guanine-cytosine base pair double-strand DNA. The Density Functional Theory method was used at B3LYP/6-31G level of theory to accomplish the objectives of the investigation. The relative energy in the 3 methylated guanine-cytosine base pair double-strand DNA molecule showed that N7 sites in the guanine base have the lowest energy, followed by N3, and C8 sites. It was found that the addition of a methyl group at the C5 atom in the cytosine base does change the stability of the C8 sites in the 3 methylated guanine-cytosine base pair double-strand DNA molecule, but the associated muon hyperfine coupling constant (HFCC) is not affected. The results of this study indicate that there will be no overlaps in the resonance dips due to N7, N3, and all C8 sites of the guanine bases and N3, C5, and C6 sites of the cytosine bases in the Avoided Level Crossing Muon Spin Resonance spectrum.
On the Interaction between Trichogramma chilonis and Jatiroto Flies with Stem Borer Pests in Sugarcane Plantation Fauzi, Rifky; Mufidah, Zunanik; Maretta, Gres; Edriani, Tiara Shofi; Rizka, Nela; Mukhaiyar, Utriweni; Utami, Riani; Haryani, Sri; Saefudin, Saefudin; Styaningrum, Amalia; Soewono, Edy
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.56.3.3

Abstract

Pests in sugarcane plantations are a major cause of damage, which could lead to severe damage to the crop, reduction of sugar quality, and significant economic loss. One of the major pests known in sugarcane plantations is stem borer (Chilo sacchriphagus), which attacks the canes. Two primary parasitoids, Trichogramma chilonis, which predates the stem borer eggs, and the Jatiroto fly (Diatraeophaga striatalis), which predates the stem borer larvae, are discussed here. This paper presents a time-dependent ten-dimensional dynamical mathematical model consisting of four-stage stem borer compartments, three-stage Trichogramma compartments, and three-stage Jatiroto compartments. Simulations are presented to describe the phenomenon of Trichogramma predation, Jatiroto predation, and simultaneous predation of both predators. It is shown that the release rate of each predator and a combined release of two predators can significantly reduce the infestation levels to a tolerable level for sugarcane production. The oscillatory dynamics of the stem borers and the Jatiroto flies affected the release timing strategy based on the level of infestation in the field. The results are expected to help us better understand the predator-prey phenomenon in the field and improve the forecasting of infestations in the field.
Discretization and Associated Asymptotic Behavior for the Lax Equation with Skew-symmetry Shinjo, Masato; Kitakado, Masaharu
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.56.3.4

Abstract

The computation of matrix eigenvalues is vital for understanding various scientific phenomena. The QR method, which is based on the QR factorization of a matrix, is a common approach in numerical linear algebra. In integrable systems, the one-step process of the QR method is related to the time evolution of the Lax equation. In this paper, we clarify the relationship between the QR method, which incorporates an origin shift parameter, and the Lax equation with skew-symmetry. Furthermore, we show the asymptotic convergence of discretization based on matrix factorization of the Lax equation with skew-symmetry as discrete time approaches infinity.
An Algorithm to Construct a Tridiagonal Matrix Factored by Bidiagonal Matrices with Prescribed Eigenvalues and Specified Entries Kondo, Koichi
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.56.3.5

Abstract

This paper presents an algorithm to construct a tridiagonal matrix factored by bidiagonal matrices with prescribed eigenvalues and specified matrix entries. The proposed algorithm addresses inverse eigenvalue problems (IEPs) constrained by LR decomposition. Using techniques from discrete soliton theory, we derive recurrence relations that connect matrix entries and eigenvalues. The algorithm systematically computes unknown entries in the matrix from given spectrum data and partial matrix information. Several examples, including cases with real, complex, and multiple eigenvalues, demonstrate the efficiency of the proposed algorithm. Additionally, we provide conditions under which the algorithm successfully solves the IEP.

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