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Spektra: Jurnal Fisika dan Aplikasinya

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Published by Universitas Negeri Jakarta

ISSN : 25413384 EISSN : 25413392 DOI : -

Core Subject : Science, Engineering,

Aerospace Engineering Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics

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Articles 260 Documents

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BACK MATTER SPEKTRA VOLUME 7 ISSUE 2, SEPTEMBER 2022 Editor Spektra
Spektra: Jurnal Fisika dan Aplikasinya Vol 7 No 2 (2022): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 7 Issue 2, September 2022
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.072111

THE DENSITY FUNCTIONAL THEORY STUDY OF Li-ION DIFFUSION IN Na-DOPED Li4Ti5O12 AS LITHIUM-ION BATTERY ANODE Achda Fitriah; Anugrah Azhar; Adam Badra Cahaya; Edi Suprayoga; Muhammad Aziz Majidi
Spektra: Jurnal Fisika dan Aplikasinya Vol 7 No 3 (2022): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 7 Issue 3, December 2022
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.073.04

Spinel phase lithium titanate (Li4Ti5O12 or LTO) has been studied as an alternative anode material with a “zero-strain” characteristic structure to improve safety, cycling stability, and rate performance. LTO offers stable Li-ion diffusion at a higher charge-discharge rate without noticeable structural change. However, LTO exhibits low electronic conductivity and low Li-ion diffusion compared to graphite-based anode materials, limiting its rate capability. In this study, we investigate the impact of Na atom doping on the diffusion rate in the Li4Ti5O12 (LTO) spinel phase using the density functional theory (DFT). Based on the nudged elastic band (NEB) calculation, we obtain the energy barrier values and each diffusion pathway, with barrier energy varying about 0.3~0.4 eV and affecting the value of the diffusion constant obtained. The study reveals the role of Na atom doping in the lithium-ion diffusion in NaxLi4-xTi5O12 for battery anode material.

MAGNETIC FIELD-DEPENDENT ELECTRIC CURRENT ON A PERIODIC POLY(DA)-POLY(DT) DNA MOLECULE STRUCTURE Efta Yudiarsah
Spektra: Jurnal Fisika dan Aplikasinya Vol 7 No 3 (2022): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 7 Issue 3, December 2022
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.073.05

An electric current flowing on the Poly(dA)-poly(dT) DNA molecule structure has been calculated. The current was calculated from transmission probabilities by employing Landauer-Buttiker formalism. Green’s function technique has been used for obtaining the transmission probabilities. The DNA molecule structure was modeled within the tight-binding Hamiltonian model approach. The model takes into account electron hopping parameters which are dependent on the magnetic field as well as the electric field. The presence of a magnetic field causes the Peierls phase factor on the electron hopping parameters. The calculation results at low electric voltages show that after decreasing, the electric current oscillates with the magnetic field. However, at higher electric voltages, the electric current is increasing and oscillates with the magnetic field.

FRONT MATTER SPEKTRA VOLUME 7 ISSUE 3, DECEMBER 2022 Editor Spektra
Spektra: Jurnal Fisika dan Aplikasinya Vol 7 No 3 (2022): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 7 Issue 3, December 2022
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.07300

BACK MATTER SPEKTRA VOLUME 7 ISSUE 3, DECEMBER 2022 Editor Spektra
Spektra: Jurnal Fisika dan Aplikasinya Vol 7 No 3 (2022): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 7 Issue 3, December 2022
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.073111

COMBINED METHOD OF BULK MATERIAL SHIELDING EVALUATION FOR 200 MEV HIGH ENERGY NEUTRON SOURCE USING PHITS MODELLING AND PARTIAL DENSITY Aliyah, Fitrotun; Rahman, Azhar Abdul; Md Radzi, Yasmin; Kambali, Imam
Spektra: Jurnal Fisika dan Aplikasinya Vol. 8 No. 1 (2023): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 8 Issue 1, April 2023
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.081.01

Neutron encounters difficulties in shielding protection. Thus, many researchers have performed simulation and experimental research on neutron shielding materials. The characteristic of materials is highly dependent on neutron energy. The evaluation of neutron shielding for various materials, such as iron, concrete, aluminum, and borated polyethylene (BPE), was conducted in this paper through simulation using a Monte Carlo code of PHITS 3.27 and calculation via partial density method. A mono-energetic neutron source with an energy of 200 MeV is emitted perpendicular to the shielding material with a thickness of 105 cm. The parameters measured in this analysis include flux, fast neutron removal cross-section, neutron depth dose, ambient dose H*(10) equivalent, and neutron dose reduction factor (RF). Results show that iron is a good material against high-energy neutron and secondary photon radiation at the energy range with the highest removal cross-section and the lowest RF value (0.39), followed by concrete, BPE, and aluminum. The integrated fluence and effective dose profiles were consistent with previous results in the literature. Benchmarking calculation of neutron dose RF was conducted with other publications and was in good agreement within the value range.

THE CORRELATION BETWEEN ELECTRIC CURRENT PRODUCED AND THE LIGHT SOURCE DISTANCE IN PHOTOELECTRIC EFFECT EXPERIMENTS Fitri, Upik Rahma; Budi, Esmar; Nasbey, Hadi; Ziveria, Mira; Muhara, Intan
Spektra: Jurnal Fisika dan Aplikasinya Vol. 8 No. 1 (2023): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 8 Issue 1, April 2023
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.081.06

In experimental observations of the relationship between the electric current generated and the distance of the light source on the Planck constant device, it can show a comparison between the electric current generated and the variable distance of the light source. The experimental equipment specifications use the Planck constant experimental set with a 12v/35w tungsten halogen lamp, output 15v, accuracy +-0.2%, power requirement 220V, fuse rating 0.5A and red filter. Experiments using the concept of the photoelectric effect phenomenon begin by irradiating metal materials with constant photon light and then the light passes through a red light filter with a wavelength of 635 nm. The use of a filter is done by placing a 635 nm light filter on the light propagation path to the metal material, so that the light that passes through the filter is only light with a wavelength of 635 nm. The choice of the red filter is due to the fact that the frequency of light with a wavelength of 635 nm can cause electrons to come out of the metal as a result of photons hitting electrons in the metal. After the metal material is irradiated with photon light, the electron charges on the metal will be disturbed and come out of the metal. The movement of these electrons produces an electric current whose value can be seen. By testing distances of 18, 20, 22, 24, 26, 28, and 30 cm, the results of a current value of 0.528 are obtained; 0.382; 0.295; 0.232; 0.182 and 0.154. From these experiments it was shown that the further away the light source, the smaller the electric current generated due to the light. This is because the closer the distance to the light source, the more light intensity hitting the metal, this results in a greater number of photons hitting the metal.

HIGH STRENGTH MANGO LEAF WASTE/POLYURETHANE COMPOSITE REINFORCEMENT USING QUARTZ MATERIAL Masturi, Masturi; Alighiri, Dante; Choirunnisa, Fadhillah; Kirana, Kurnia Galuh Candra
Spektra: Jurnal Fisika dan Aplikasinya Vol. 8 No. 1 (2023): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 8 Issue 1, April 2023
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.081.05

Quartz stone contains silica components (SiO2) which have the ability as a reinforcement material for composite materials. Quartz SEM-EDX testing shows that the quartz silica comonent is 69%. Other components contained in quartz are 34% MgO and 2% CaO. Therefore, quartz stone is used as a reinforcing material in mango leaf waste composite materials. Meanwhile, compressive strength testing of composite materials was carried out with variations of Polyurethane (PU) polymers, namely 1, 2, 3, 4, 5, 6, and 7 grams, obtaining the highest maximum pressure at 6 grams polymer mass, which is 38.91 grams. Testing of composite materials that have been given a mixture of quartz stone with a mass of Polyurethane (PU) 6 grams and a quartz stone variation of 0.03; 0,06; 0,09; 0,12; 0,15; and 0.18 grams obtained the maximum power most optimally there is a quartz mass of 0.06 grams of 40.47 grams. The strength of mango leaf composite meets the strength standard for building materials, namely concrete with a value of 20-150 MPa. This shows that quartz stone can be a composite reinforcement comprehenent for mango leaf waste.

EXPLORING THE INTERCONNECTEDNESS OF COSMOLOGICAL PARAMETERS AND OBSERVATIONS: INSIGHTS INTO THE PROPERTIES AND EVOLUTION OF THE UNIVERSE Nasution, Budiman; Siagian, Ruben Cornelius; Nurahman, Arip; Alfaris, Lulut
Spektra: Jurnal Fisika dan Aplikasinya Vol. 8 No. 1 (2023): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 8 Issue 1, April 2023
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.081.03

This research aims to investigate the relationship between Confidence Interval, Hubble Parameter, Comoving Distance, and Distance-Volume Relationship, which are important equations in cosmology. The Confidence Interval equation is used to estimate the range of values for the difference between the mean redshift and Hubble parameter. The Hubble Parameter equation is used to measure the expansion rate of the universe, while the Comoving Distance equation is used to calculate the distance between two objects in the expanding universe, and the Distance-Volume Relationship equation is used to calculate the distance between an observer and a cosmic object based on the object's redshift. This study seeks to address several research questions, including the accuracy of estimating parameters using these equations and the potential for developing more precise equations. The study employs cosmological data analysis using the R program to analyze existing data and gain a better understanding of cosmological parameters. The results of this research contribute to our understanding of the nature and evolution of the universe, providing insights into the distribution of matter and the role of dark matter and dark energy in shaping the universe's evolution. By examining the relationship between cosmological parameters, this study enables us to make predictions about cosmic phenomena and improve the accuracy of future measurements. The findings of this research have implications for cosmological research and can aid in the development of more accurate models and theories in the field of cosmology. Overall, this study provides valuable insights into the fundamental equations in cosmology and their relationships, advancing our understanding of the universe's dynamics and evolution.

CHARACTERIZATION OF ENERGY BAND GAP THIN FILM BaTiO3 – BaZr0.5Ti0.5O3 USING DIFUSION REFLECTANCE SPECTROSCOPY (DRS) METHOD Dewi, Rahmi; Manalu, Wesly Arianto; Asrinaldo, Brian Noval; Rini, Ari Sulistyo; Yanuar, Yanuar
Spektra: Jurnal Fisika dan Aplikasinya Vol. 8 No. 1 (2023): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 8 Issue 1, April 2023
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.081.02

Ferroelectric material is a dielectric material that has a high dielectric constant value so that it can be made in the form of thin films. Its application is based on electro-optical properties, one of which is the infrared thermal switch. This paper aims to determine the bandgap energy (Eg) of a 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 thin film. The 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 thin film is a semiconductor material with the valence band and conduction band separated by an energy bandgap (Eg). Thin films of 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 were grown on FTO substrates using the sol-gel method. The films of 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 were annealed at different temperatures of 700°C, 750°C and 800°C within 1 hour. Characterization was carried out using Ultra Violet Visible (UV-Vis) spectroscopy to determine Eg using the Diffusion Reflectance Spectroscopy (DRS) method. The DRS method was found to be better for solid materials considering the scattering component. The UV-Vis characterization results show that an increase in annealing temperature causes a decrease in Eg. For example the values at 700°C, 750°C and 800°C are 3.5 ± 0.01 eV; 3.3±0.01 eV and 3.2±0.01 eV. The decrease in Eg is related to the diffusion of Barium Titanate (BaTiO3) ions into the Barium Zirconium Titanate (BZT) lattice forming a new sub-gap which in turn gives BT-BZT the ability to absorb lower light. Lower light absorption means more capable optics for multilayer systems.

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