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POSITRON
Published by Universitas Tanjungpura
ISSN : 23014970     EISSN : 2549936X     DOI : http://dx.doi.org/10.26418/positron.v10i2.42006
Core Subject : Science,
Energy Physics
POSITRON: Berkala Ilmiah Fisika (POSITRON) is a peer-reviewed open accessed Indonesian journal that publishes scientific research papers in the field of physics and its application. The journal covers a wide range of topics in physics, including conceptual studies, theoretical and experimental studies, the use of computational methods, instrumentation, and multidisciplinary studies involving physics. This journal aims to be a platform to exchange research results in physics-related topics across all scientific disciplines. POSITRON is published by Jurusan Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Tanjungpura, Indonesia, twice a year (Mei and November). This journal is accreditated SINTA 2 by RISTEKDIKTI and indexed in Directory of Open Access Journal (DOAJ), Bielefeld Academic Search Engine (BASE), Google Scholar, Science and Technology Index (Sinta), Garda Rujukan Digital (GARUDA), and Indonesia One Search (IOS). All articles in this journal are uniquely identified with DOI.
Arjuna Subject : Fisika dan Astronomi - Fisika Nuklir dan Energi Tinggi
Articles 212 Documents
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Effect of Calcination Temperature on the Powder of Freshwater Snail Shells (Sulcospira testudinaria) Properties Nugroho, Bintoro Siswo; Wahyuni, Dwiria; Asri, Asifa; Mustafa, Usliana
POSITRON Vol 13, No 2 (2023): Vol. 13 No. 2 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v13i2.70055

Abstract

Gastropod shells, such as those from the freshwater snail (Sulcospira testudinaria), have garnered interest as potential sources of calcium precursors. These shells are rich in calcium carbonate (CaCO3), which can be thermally decomposed into calcium oxide (CaO) through calcination. However, more information is needed on optimizing calcium extraction from the Sulcospira testudinaria (SST) shells. This study aims to investigate the influence of calcination temperature on the characteristics of powder of these shells. The study involves two sample treatments: uncalcined shells and shells calcined at temperatures ranging from 500°C to 1100°C for 1 hour. Fourier transform infrared spectroscopy (FTIR) analysis of uncalcined shell powder revealed the presence of aragonite functional groups within the CaCO3 structure. X-ray diffraction (XRD) analysis provided insights into the transformation of crystalline phases of CaCO3, starting from aragonite to calcite and eventually to calcium oxide, explaining the material's weight loss during calcination. The conversion of aragonite to calcite occurs between 500°C and 700°C, while optimal decomposition into CaO is achieved at 1000°C. X-ray fluorescence (XRF) analysis indicated reduced impurities in the samples post-calcination. Scanning electron microscopy (SEM) detailed the morphological characteristics of the shell powders, highlighting temperature-dependent surface features. In conclusion, the optimal calcination temperature for extracting calcium from SST shells is 1000°C. The resulting calcium oxide can be a valuable precursor for various material applications. This research contributes to the efficient utilization of biowaste resources, emphasizing the potential of freshwater snail shells in the sustainable production of calcium-derived materials.
Non-Nutritive Suck Assessment Tool Development to Characterize Sucking Patterns in Infant with Various Hunger Levels Saputra, Casmika; Inati, Iin
POSITRON Vol 13, No 2 (2023): Vol. 13 No. 2 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v13i2.69270

Abstract

Sucking abilities are critical in early infant development, and the patterns of non-nutritive suck (NNS) have been found to potentially predict neurodevelopmental issues in the future. Proper NNS assessments are essential to ensure valid conclusions. Previous studies have shown that the level of infant arousal significantly affects NNS patterns. However, the author did not find any studies that observed the influence of infant hunger levels on NNS patterns. Therefore, this study aimed to develop an NNS assessment tool to characterize NNS patterns in infants with various hunger levels. The NNS assessment was conducted using a pressure transducer connected to a pacifier. The results showed that the level of hunger significantly affected the intra-burst frequency and the sucking pressure. The more hungry the infant, the more frequent the intra-burst frequency became, while the sucking pressure tended to decrease. The intra-burst frequency of infant sucking was 2.3, 2.46, and 2.5 Hz on average for a relative hunger index of 0.67, 0.83, and 1.0, respectively. The NNS pressure of infant sucking was 6.31, 4.51, and 2.62 kPa on average for a relative hunger index of 0.67, 0.83, and 1.0, respectively. This study's results suggest that during NNS assessments, the measurement time should consider the next feeding schedule for the infant.
Approximate Analytical Solution of the Ground State Problem of He and He-like Ions using Symmetrized-Hydrogenic States Pingak, Redi Kristian
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.75417

Abstract

The matrix method using three symmetrized-hydrogenic basis states has been applied to analytically obtain an approximate solution to the Schrödinger equation of the Helium atom and some He-like ions (2<Z<10). This study aims at obtaining more accurate ground state energies of the systems compared to our previous calculation using un-symmetrized basis states and some other simple calculations in the literature. The contribution of the symmetrized basis states on the ground state energies of the systems is also investigated. The time-independent Schrödinger equation involving a 3×3 Hamiltonian matrix, formed by hydrogenic s-states, was analytically solved to obtain three energy eigenvalues of the systems as well as their corresponding eigenvectors. Results showed that the 1s2 energies of the systems were more accurate than our previous unsymmetrized basis calculations, with significant error reduction observed for He and Li+. With the same matrix size, the ground state energies of He and He-like ions obtained from three symmetrized basis states in this study were found to be closer to the exact and experimental energies than those obtained from unsymmetrized basis states. It was also demonstrated that the |100;100> state made the largest contribution to the ground state energies of the systems, i.e. about 90.9% for He and around 99.9% for Ne8+, and consequently the smallest contribution came from the other two symmetrized states (less than 1%). To conclude, the calculated ground state energies were more accurate than some other simple calculations reported in the literature.
Peningkatan Kadar Zirkonium Silikat dalam Pasir Puya, Residu Penambangan Emas dari Kecamatan Monterado Kabupaten Bengkayang Provinsi Kalimantan Barat Kartika, Novi; Silalahi, Imelda Hotmarisi; Zaharah, Titin Anita; Aritonang, Anthoni B
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.66460

Abstract

Pasir zirkon memiliki kandungan zirkonium berkisar antara 30-50% berat di beberapa lokasi penambangan emas yang berada di Kalimantan Barat. Analisis XRF memperlihatkan persen berat unsur dalam pasir hitam non magnetik (PHNM) dari pasir zirkon yang berasal dari Kecamatan Monterado, Kabupaten Bengkayang adalah 48,05% Zr; 3,35% Si serta unsur lain seperti 20% Ti, 18,95% Fe dan 1,62% Hf. Peningkatan kadar zirkon dilakukan melalui beberapa tahapan yaitu metode fusi alkali dengan perbandingan massa PHNM terhadap massa NaOH yaitu 10 gram : 5 gram (2:1) pada variasi temperatur 700 °C dan 800 °C selama 2 jam, kemudian tahap pelindian menggunakan HCl 2% diikuti oleh pelindian lanjut dalam HCl 37%. Perbedaan temperatur dalam reaksi fusi alkali menghasilkan perbedaan komposisi Zr, dimana pada temperatur 700 °C adalah 88,45% sedangkan pada temperatur 800 °C adalah 90,11% dengan rasio Zr/Si masing-masing adalah 5,33 dan 4,85. Temperatur reaksi fusi alkali pada 800 °C memperlihatkan komponen Zr lebih tinggi dengan rasio Zr/Si yang mendekati ZrSiO4 yaitu 3,25. Analisis jenis mineral menggunakan XRD padat memperlihatkan keberadaan mineral ZrSiO4 dengan struktur kristal tetragonal, memiliki puncak utama pada 2θ adalah 20,04°-20,10°, 26,94°-26,98°, dan 53,48°-53,49°. Ukuran kristal ZrSiO4 berdasarkan perhitungan menggunakan persamaan Debye Scherrer berada dalam kisaran 120,78 nm (2θ = 20,10°), 122,30 nm (2θ = 26,98°), dan 133,17 nm (2θ = 53,48°). Rendemen perlakuan PHNM dengan rangkaian proses reaksi fusi alkali, reaksi basa dan pelindian menggunakan HCl adalah berkisar 33% dengan kadar zirkon silikat dalam produk akhir meningkat dari 46,2% menjadi 90,11%.
Effect of Heat Leakage on Relativistic Quantum Lenoir Engine Performance with a Massless Boson as Working Substance in the Infinite Potential Box Saputra, Yohanes Dwi; Rahastama, Swastya; Firdaus, Rohim Aminullah
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.64658

Abstract

A study on the effect of heat leakage on power output, thermal efficiency, and reversibility rate in a relativistic quantum Lenoir engine has been conducted. Initially, we analogize the quantum working substance of the engine, a massless boson trapped in an infinite potential box with a movable right wall, as an ideal gas confined in a pistoned cylinder. Then, the total work, heat input, and heat output of each engine cycle which consists of isochoric, adiabatic expansion, and isobaric compression are extracted by applying the concept of quantum thermodynamics. Finally, power output, thermal efficiency, and reversibility rate of the engine are calculated for different variations of the heat leakage constant. The results are the relationship between several parameters which are expressed in the graph of thermal efficiency vs. compression ratio, graph of efficiency/normal efficiency vs. compression ratio, power output vs. efficiency, and reversibility rate vs. compression ratio. The conclusion is that an increase in heat leakage has an effect on reducing the efficiency and reversibility rate of the engine but does not affect its power output. This work will provide a new chapter for further research related to the use of the boson particle as a working substance in the quantum heat engine, especially the study of the heat leakage effect on engine performance.
The Effect of Burnable Poison Np-237 on the Conceptual Design of the GFR-2400 MWt Using MCANDLE Burnup Strategy Monado, Fiber; Berliani, Berliani; Supardi, Supardi; Royani, Idha; Ariani, Menik; Kaban, Hadir; Su'ud, Zaki
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.65433

Abstract

This study was used to design the Gas-cooled Fast Reactor (GFR) with 2400 MWt power as well as to implement a modified CANDLE (MCANDLE) burning strategy. Metallic uranium with Neptunium-237 at a concentration of 1% to 10% was used as burnable poison in the fuel while helium was applied as a coolant. Neptunium has been produced in conventional reactors by the decay product of plutonium obtained from U-238. This isotope has a relatively high absorption cross-section. As a nuclear waste, it is very useful to utilize as a burnable poison to reduce waste in the future and extend reactor operation lifetime with negligible reactivity. Moreover, the reactor was designed to operate for 100 years of burnup. Nuclear Fuel cell level calculations were conducted using the PIJ module and the reactor core was analyzed using the CITATION module contained in the SRAC. The core height was found to be 420 cm while the diameter was 300 cm and it was designed to have a refueling period of ten years. The survey parameters evaluated include burnup level, factor multiplication, conversion ratio, atomic density, and power distribution. The calculation conducted at the fuel cell level showed that the maximum value in the 76th year for the infinite multiplication factor was 1.30097. It was also discovered that the reactor core for the effective multiplication factor parameter with a fuel fraction of 55% was 1.094 without the addition of burnable poison.
Aplikasi Karbon Aktif Cangkang Kelapa Sawit (Elaeis guineensis) sebagai Pigmen Toner Hitam pada Elektrofotografi dengan Polimer Stirena Akrilik-Vinil Pirrolidine Candini, Ayu Risti; Ginting, Delovita; Syahputra, Romi Fadli; Piza, Piza; Nurhamiyah, Leli
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.70064

Abstract

Toner merupakan campuran pigmen atau pewarna, serbuk logam, dan polimer. Tujuannya adalah menghasilkan toner elektrofotografi yang memanfaatkan cangkang kelapa sawit sebagai karbon aktif untuk zat pewarna dan melihat pengaruh komposisi bahan polimer stirena akrilik dan vynil pirrolidine yang digunakan untuk pembuatan toner. Metode pembuatan karbon aktif melibatkan aktivasi fisika dan kimia cangkang kelapa sawit, diikuti oleh penyesuaian ukuran partikel dan proses pirolisis. Proses pembuatan toner dengan metode agregasi emulsi kimia yang memiliki keunggulan, seperti menghasilkan ukuran partikel toner yang kecil, lebih sempit, dan efisiensi toner yang lebih tinggi. Analisis ukuran partikel (PSA) pada sampel karbon aktif menunjukkan bahwa ukuran partikelnya sudah berada dalam rentang mikropartikel yakni nilai rata-rata partikel diperoleh 2,1223 µm dan karakterisasi fisis meliputi kadar air, kadar zat menguap, kadar karbon terikat sudah memenuhi SNI 06-3730-1995. Hasil pengujian ukuran partikel sampel toner TE2 diperoleh nilai rata-rata partikel 22,0323 µm dan merupakan hasil cetak optimum dengan nilai red green blue rata-rata 30,6355 yang menandakan warna yang dihasilkan mendekati hitam. Hasil penelitian juga menunjukkan polimer vinil pirrolidine memiliki pengaruh optimum terhadap kualitas cetak dan ukuran partikel lebih kecil. Aplikasi karbon aktif cangkang kelapa sawit dalam elektrofotografi pada penelitian ini menawarkan solusi berkelanjutan dan inovatif untuk pengembangan toner hitam yang ramah lingkungan
Palm Oil Mill Effluent Biochar as An Alternative Potassium Source: Effect of Pyrolysis Time and Its Kinetic Release Krisnanti, Gendis Yayi; Gusrizal, Gusrizal; Wahyuni, Nelly
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.69833

Abstract

Palm Oil Mill Effluent (POME) is one of the waste products of palm oil processing that can be processed into a biochar. POME biochar contains high levels of nutrient, such as NPK which can be used an alternative potassium source material. This study aims to produced biochar from POME and the influence of pyrolysis time on the characteristics and its kinetic release. Biochar production from POME was conducted at 300oC with pyrolysis time variation of 1 hour, 3 hours and 5 hours. Biochar characterization was conducted using Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX), Surface Area Analysis (SAA). Study of potassium release was conducted by mixing one gram amount of biochar with 0.01 M CaCl2 as a function of time. The used kinetics modelling in this study are first-order, second-order, pseudo-first order, pseudo-second orde. The results showed that the biochar yield decreased, while the biochar pH value, exchangeable potassium, non-exchangeable potassium  and surface area increased with the increasing of pyrolysis time. The pseudo- second order model is the most fitted model to describe the potassium release. The pseudo-second order kinetics model gave K release rates of 0.018; 0.024; 0.020; 0.014 (mg g-1min-1), the qe values are 0.814; 0.839; 0.927; 1.111 (mg g-1), respectively.
Comparison of Hydrocarbon Volumetric Calculation between Cell-Based Model and Numerical Integration Oktaviani, Vania; Saroji, Sudarmaji; Trisna, Muhammad Destrayuda
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.61374

Abstract

Volume estimation for hydrocarbon reserves is a challenging yet pivotal task in engineering for exploration and production. Advances in technology now enable us to compute volume integration using programming computation. Various approaches using numerical integration, including the trapezoidal, pyramidal, and Simpson's rule, along with cell-based models as comparative methods can be used for the calculation of hydrocarbon volume. In this study, original oil in place (OOIP) is employed to determine reserve oil volume.  The OOIP values obtained are 8.55 million m3 through cell-based calculations, 8.63 million m3 via the trapezoidal approach, 8.58 million m3 using the pyramidal method, and 8.57 million m3 with Simpson's 3/8 rule. The relative error ratio percentages between the cell-based model as the reference value and the numerical integration calculations as the measured values are 0.93% for the trapezoidal method, 0.35% for the pyramidal method, and 0.23% for Simpson's 3/8 rule. Simpson's 3/8 rule demonstrates the closest mathematical result to the cell-based model. Within this margin of error, the methodologies have been demonstrated to proficiently compute hydrocarbon reserves from real data through simplified and abbreviated processes.
Geoelectric Modelling Based on Bessel Functions Integral and Damped Least-Square Inversion for Layered Earth Models Saefullah, Asep; Srigutomo, Wahyu; Rostikwati, Diana Ayu
POSITRON Vol 14, No 1 (2024): Vol. 14 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v14i1.68248

Abstract

Apparent resistivity formulations of a geoelectric method for layered Earth have been obtained analytically in the Bessel functions integral. This formulation is obtained through the application of two boundary conditions. First, the current density is zero at the Earth's surface. Second, current density and electric potential are continuous at the boundary between the layers. Geoelectric modelling can be done using several model parameters through this formulation. The modelling results show that apparent resistivity formulations based on Bessel function integrals can simulate apparent resistivity curves for layered earth models. The inversion process uses the apparent resistivity formulation based on Bessel function integrals. In this study, the inversion process uses a dumped Least-squared inversion method. The first step begins by testing the inversion program using synthetic data. After that, the inversion program is used in field data. The inversion results using field data from geoelectric data in Mount Pandan, East Java, show that the program was well done, with a minimal error value of 1.24%.

Page 19 of 22 | Total Record : 212

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