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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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Magnetic Characterization of Fine Sediment in the Solo Basin Indonesia Budi Legowo; Anti Fatkhul Qoiriah; Artono Dwijo Sutomo; Shandiyano Putra; Wiwit Suryanto; Budi Purnama
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 2 (2023)
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.2023.55.2.1

Abstract

The magnetic characteristics of fine sediment samples from the Solo Basin are reported in this paper. Magnetic fine sediment was identified by magnetic susceptibility mapping based on sampling of 182 points. Then, a depth analysis (on 7 selected sampling points) was performed using X-ray fluorescence spectrometry, which showed an iron oxide content of up to 55.42%, while X-ray diffractometry confirmed magnetite minerals with crystallite size ≤100 nm. Further, the vibrating sample magnetometry results verified the magnetic characteristics under a single-domain configuration. The characteristic magnetic susceptibility map showed that there is a lithogenic effect on sediment in the Solo Basin. In addition, anthropogenic activities seem to play a pivotal role in distributing magnetic materials.
Characterizing Earthquake Source Parameters and b Value Variations in Subduction and Fault Segments: Implications for Seismic Hazard Analysis Abdi Jihad; Vrieslend Haris Banyunegoro; muksin umar; marwan ramli; Syamsidik Syamsidik; yunita idris; Andi Azhar Rusdin
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 1 (2024): (In Progress)
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.2024.56.1.1

Abstract

Earthquake sources in Aceh have distinct characteristics. Understanding the seismic characteristics of each earthquake source is crucial for comprehending earthquake cycles and assessing seismic hazards. A key parameter in characterizing an earthquake source is the b-value, which indicates the relationship between the number of earthquakes and their magnitudes, influenced by the magnitude of completeness (Mc). The present study analyzed the seismic characteristics of two subduction zone segments and sixteen fault segments using the least squares method on selected earthquake data specific to each segment. The analysis revealed that the b-value ranged from 0.5 to 0.6 in the subduction zone segments and from 0.3 to 1.0 in the fault segments. These variances in b‑value reflect the different seismic characteristics of the earthquake sources that shape the tectonic settings in Aceh. A lower b-value signifies an elastic zone capable of holding higher stress levels, whereas a higher b-value indicates a brittle zone that can only withstand lower stress levels.
A Pyrone and Flavonoid Derivatives from Cryptocarya crassinervia and their Inhibitory Properties against Receptor Tyrosine Kinases Dian Nugraheni; Elvira Hermawati; Hendra Helmanto; Dikhi Firmansyah; Yana Maolana Syah; Lia Dewi Juliawaty
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.2024.55.3.5

Abstract

A new a-pyrone, i.e., cryptocrassinervione (1), and a new flavone glycoside, i.e., kaempferol-3-O-rhamnosyl-2-O-apiofuranoside (4), were isolated from EtOAc extract of Cryptocarya crassinervia leaves. Along with these compounds, two known flavone glycosides, namely afzelin (2) and quercitrin (3), were also isolated. The structures of the new compounds were determined based on NMR and mass spectral data. Compounds 1–4 were examined against eight receptor tyrosine kinases (RTKs) (EGFR, HER2, HER4, IGF1R, InsR, KDR, PDGFRα, and PDGFRβ), which showed that these compounds were moderately active against EGFR, with inhibition percentages of 55, 49, 41, and 44%, respectively. They were weakly active against HER2, with inhibitions of 17, 20, 18, and 16%, respectively. However, they were not active against the rest of the RTKs. Nevertheless, compounds 1–4 have potency as inhibitors of EGFR.
Sedimentary Facies, Palynology, and Organic Geochemistry of Eocene Kalumpang Formation in Lariang and Karama Areas, West Sulawesi, Indonesia Rakhmat Fakhruddin; Nisa Nurul Ilmi; Edy Sunardi; Taufik Ramli; Agus Ardianto Budiman; Indra Nurdiana; Dzul Fadli
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 2 (2023)
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.2023.55.2.3

Abstract

The Kalumpang Formation was deposited in a delta plain setting. A Middle to Late Eocene age (Proxapertites operculatus zone) was inferred from palynological analysis, with a paleoenvironment in a coastal plain setting with a strong terrestrial influence. Samples from the Kalumpang Formation indicate a marginal to early mature stage for hydrocarbon generation. It is mostly composed of gas-prone to oil and gas-prone Type III kerogen facies. The biomarker character of both the rock and oil samples suggests a terrestrial origin, with a significant contribution of estuarine or bay organic material. The oil derives from a non-carbonate lithology, while the rock samples are from carbonate/calcareous shale origin. The abundance of oleanane compound and C30 resins suggests higher plant angiosperm input of Late Cretaceous or younger age for both the rock and the oil samples. The oil seep contains more abundant oleananes compared to the carbonaceous mudstone of the Kalumpang Formation. This suggests that the oil originated from more marine facies than the rock samples, which were deposited in a delta plain setting. This study demonstrated the agreement of depositional environment interpretation and age assessment between lithofacies, palynological, and organic geochemistry analysis.
Deformation under a Young Volcanic Covered Area in Southern Garut, Indonesia: Insight from 3D Gravity Modelling Ilham Arisbaya; Edy Wijanarko; Prihadi Sumintadireja; Warsa Warsa; Hendra Grandis
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.2024.55.3.3

Abstract

Destructive earthquakes are frequently related to inland active faults. In recent years, a significant number of shallow earthquakes with low magnitude have occurred in southern Garut, West Java, Indonesia. Two earthquakes, with magnitudes of M4.2 and M3.9 in 2016 and 2017, respectively, have caused significant damage and were interpreted as indications of an active fault. We used publicly available gravity data to infer the subsurface structure that may be related to recent seismic activity. We used spectral analysis and filtering techniques for the regional-residual anomaly separation and anomaly enhancement to show the basin structure in the study area. 3D gravity inversion modelling was performed to obtain the subsurface density distribution. The result indicates the sedimentary layers with a density of 2.4 to 2.5 gr/cm3 with an underlying basement with a density of 2.65 gr/cm3. An intra-basin basement high with an NE-SW trend divides the basin into two sub-basins. This local basement high can be associated with a magmatic intrusion body and a series of young volcanic bodies located at the northeastern end of the basin. Our results emphasize a possible strong interaction between the tectonic and magmatic activities in this region.
Structural and Magnetic Properties of Barium-Strontium-Hexaferrite Material Ba0.6Sr0.4Fe10-xCoxMnTiO19 (x = 0.5; 1.0; and 1.5) as Microwave Absorbers Yohanes Edi Gunanto; Maykel Manawan; Maya Puspitasari Izaak; Henni Sitompul; Yunasfi Yunasfi; Wisnu Ari Adi
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.2024.55.3.1

Abstract

We discuss the structure properties of Ba0.6Sr0.4Fe10-xCoxMnTiO19(BSFCMTO) for x = 0.5, 1.0, and 1.5 that influence its magnetic properties as a microwave absorber. A solid-state reaction method using high-energy milling was used to synthesize hexaferrite. There were no structural changes when the Co2+ ion was substituted for the Fe3+ ion; the structures of all samples were hexagonal and the space group was P63/mmc. The surface morphology had heterogeneous particles with a size of 300 to 600 nm. The magnetic properties tended to decrease with an increasing number of Co2+ ion substitutions. The reflection loss (RL) had a minimum value of -14.89 dB. This value was reached at a frequency of 10.96 GHz and had a bandwidth at 1.24 GHz with a sample thickness of 1 mm in the Ba0.6Sr0.4Fe9.9Co0.1MnTiO19 sample.
Structural and Photoluminescence Properties of Ca2+-Substituted Self-Activated Photoluminescence Material of Na2TiSiO5 Dzaky Dian Ruhimat; Fainan Failamani; Bambang Prijamboedi
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 2 (2023)
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.2023.55.2.6

Abstract

The effects of Ca2+ substitution on the structural and optical properties of Na2TiSiO5 were studied. It was expected that the Ca2+ ions would replace Na+ ions and change the coordination of Ti4+-O2- as a luminescence center. Na2(1‑x)CaxTiSiO5 (x = 0.00, 0.50, 1.00) samples were synthesized using the solid-state method, and their structural properties, the local Ti4+-O2- coordination, the absorption spectra, and the photoluminescence properties were studied. The electronic structure of Na2(1-x)CaxTiSiO5 with x = 0.00 and 1.00 was also calculated using the Full Potential Linear Augmented Plane Wave (FP-LAPW) method to explain some of the observed properties. The Ca2+ substitution resulted in a phase transformation from an orthorhombic to a monoclinic structure. The number of TiO6 octahedra increased with the increase of Ca2+ and correlated with the decrease of PL emission intensity of the Na2(1‑x)CaxTiSiO5 samples. The Ti-3d bands in the CaTiSiO5 were more dispersive than in the Na2TiSiO5 and were responsible for the PL emission intensity reduction.
Optical Spectroscopy and Photoionization Model of Planetary Nebula NGC 6572 Muhammad Fajrin; Hakim Luthfi Malasan; Evan Irawan Akbar
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 2 (2023)
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.2023.55.2.2

Abstract

We investigated NGC 6572 through optical spectroscopy to determine its kinematical and chemical properties. Two intermediate dispersion spectra (R~5000) centered around Hα and Hβ were used to derive the nebular expansion velocity from emission lines associated with Hα, Hβ, [OIII], [NII], and [SII] ions. A low dispersion spectrum (R~1000) was used to determine the nebular electron temperature, density, and chemical composition. We performed photoionization modeling to construct a self-consistent nebular model, while intermediate-resolution spectral images showed the global elliptical structure of the nebula. The expansion velocity deduced from most of the emission lines is consistent with the typical expansion velocity of planetary nebulae, i.e., around 15-20 kms-1. The nebular physical properties align well with those determined by other studies. The nebular abundances were found to be lower than the solar abundances (except for oxygen) but still comparable with the abundances derived by other researchers. The photoionization model generated spectral lines that are consistent with the lines found in the observations. Further spectroscopic observations with higher resolution and wider range at various position angles will be very useful to reveal a more complete and detailed structure of the nebula and to improve the determination of the nebular physical properties.
Geochemistry of I-type Volcanic Arc Granitoid From Tanggamus Regency, Southern Sumatra Ronaldo Irzon; Kurnia Kurnia; Muhammad Firdaus; Eko Yulianto; Firdaus Djabar
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 2 (2023)
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.2023.55.2.5

Abstract

Granitoid intrusion of several provinces on Sumatra is correlated with Southeast Asia tectonics that have occurred since the Permian. Granites from several volcanic arc provinces are located along the western part of Sumatra Island and are found near Bukit Barisan. This study describes the geochemical character of granitoid from the Tanggamus region and its surroundings near the Bukit Barisan cluster. After megascopic description in the field, major oxides, trace elements, and rare earth elements in rock samples were measured using X-ray fluorescence and inductively coupled plasma-mass spectrometry devices. The samples were intermediate to acidic intrusive rocks with SiO2 ranging between 61.35% and 75.29%. The rocks can be described as diorite to granodiorite and were formed as a result of subduction processes. The granitic rock samples showed I-type features of A/CNK value <1.1, volcanic arc granite affinity, K2O/Na2O ratio, and magnesian properties. The total rare earth content was medium with an average of 43.97 ppm. The similarity of the rare earth normalized diagram against the chondrite value indicates that the samples come from an identical origin.
Particle Size Optimization of Melinjo (Gnetum gnemon L.) Seed Hardshell: A Potential Antioxidant Alternative Marlina Indriastuti; I Ketut Adnyana; Rika Hartati; Heni Rachmawati
Journal of Mathematical and Fundamental Sciences Vol. 56 No. 1 (2024): (In Progress)
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.2024.56.1.2

Abstract

Natural ingredients can have extraordinary potential as alternative medicines due to their accessibility and cost-effectiveness. Application of these ingredients should consider solubility and permeability, which determine the success of pharmaceutical characteristics formulation and biological activity indication. In this context, physical manipulation, specifically particle size reduction, is an effective strategy to address these issues. Previous research has explored active compounds in the stilbenoid group, found in the outer skin, hard shell, and endosperm of melinjo (Gnetum gnemon L.) seeds, functioning as antioxidant. Based on the potential as antioxidant, stilbenoid compounds, including resveratrol, contained in melinjo seed hardshell have shown significant pharmacological effects. Therefore, this research aimed to investigate the potential of melinjo seed hardshell extract as a natural antioxidant alternative by modifying the particle size through a grinding process to obtain nanoparticles. The analysis was carried out using ball milling to enhance the solubility of melinjo seed hardshell extract by increasing the saturated solubility and surface area of the particles. The results showed that the total phenol content and the antioxidant power increased significantly (p < 0.05) after ball milling. Melinjo seed hardshell nanoextract is reported herein as a promising source of natural antioxidant from local Indonesian plants.

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