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EINSTEIN (E-JOURNAL)
Published by Universitas Negeri Medan
ISSN : 23381981     EISSN : 2407747X     DOI : https://doi.org/10.24114/einstein%20e-journ.v11i1
Core Subject : Science, Engineering,
Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Materials Science & Nanotechnology Mechanical Engineering Physics
EINSTEIN (e-Journal) is a journal managed by the Department of Physics, Faculty of Mathematics and Natural Sciences, State University of Medan. This journal is published three times a year (February, June, and October). EINSTEIN (e-Journal) is a scientific journal that publishes articles from the fields of physics. Various topics of physics articles that can be accepted in this journal are: Theoretical Physics Earth Physics Material Physics Instrumentation Physics Computational Physics Applied Physics
Arjuna Subject : Fisika dan Astronomi - Fisika dan Astronomi (Lain-Lain)
Articles 287 Documents
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MECHANICAL PROPERTIES OF HIGH-DENSITY POLYETHYLENE (HDPE) WITH TiO2 NANOPARTICLE FILLER PEG 6000 Sinaga, Sufri; Bukit, Nurdin
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.49331

Abstract

Titanium dioxide (TiO2) is a semiconductor material that has great stability so that it can be utilized as a filler material for High Density Polyethylene (HDPE) thermoplastics. This study was conducted to determine the effect of TiO2 PEG 6000 nanoparticle filler composition on the mechanical properties of HDPE thermoplastics. TiO2 was synthesized with sol gel method and then mixed with PEG 6000. Nanocomposites are made by mixing HDPE with TiO2 nano filler in a rheomixer tool with variations in filler composition (2, 4, 6, 8, 10) %wt, then molded using injection molding tools with ASTM 638 type V standards and analyzing mechanical properties using UTM (Universal Testing Machine) test equipment which includes tensile strength, elongation at break and elastic modulus. The results of XRD analysis produced a particle size of 22nm and SEM tests showed that the surface of TiO2 nanoparticles had a smooth and even surface. The sample with 8% wt filler composition variation is the sample with the best tensile strength value of 84.72 MPa, the highest elongation at break value in the sample with 4% filler of 35.5% and the highest elastic modulus in the sample with 8%wt filler composition of 729.33 MPa.Keywords: Titanium dioxide, HDPE thermoplastic, PEG 6000, Tensile test.
IDENTIFICATION OF SUBSURFACE STRUCTURE USING GEOMAGNETIC METHOD AND ROCK MINERAL ANALYSIS WITH XRD TEST IN GEOTHERMAL AREA OF PAYUNG VILLAGE KARO REGENCY Syahputri, Maharani; Kadri, Muhammad
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.51272

Abstract

This research was carried out to know the distribution of subsurface magnetic anomalies and determine the type and content of rocks based on susceptibility values in the geothermal area of Payung village, Karo district. Field measurements use PPM (Proto Precision Magnetometer), GPS (Global Position System) and compass. The data was processed using Mag2dc and surfer 13 software, to obtain susceptibility results. Determination of rock content was tested using XRD (X-Ray Diffraction). Geomagnetic data collection in the field at 40 measurement points. The research results show that there are variations in magnetic field strength at each point with values ranging from 20 nT to 380 nT. This shows that the geothermal area in Payung village has a susceptibility value ranging from 0.0013 x to 0.0088 x and is igneous rock in the form of andesite lava rock and pyroclastic rock. Igneous rocks and pyroclastic rocks are the building blocks of geothermal energy in the research area. The minerals that make up the rocks of the geothermal area in Payung village are the minerals, Asbecasite () and the mineral Quartz (). The mineral has an orthorhombic crystal system with crystal size a= 12.2842Å b= 7.6537Å c= 7.5151Å. The crystal system of the Asbecasite mineral is trigonal (hexagonal axes) with crystal size a= 8.3180Å c= 15.2640Å. Quartz with a triclinic (anorthic) system with crystal size a= 9.9320Å b= 17.2160Å c= 81.8640Å.
PHOTOLUMINESCENCE PROPERTIES OF TB3+ DOPED ON PHOSPHATE GLASS MEDIUM BY ADDITION OF FLUORIDE COMPOUNDS Simanullang, Elyzabeth; Rajagukguk, Juniastel; Hutahaean, Juniar; Sarumaha, Chayani Setiades
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.54202

Abstract

Research has been conducted on the effect of the addition of fluoride compounds on the photoluminescence properties of Tb3+ doped on phosphate glass has been found. with the composition of glass samples are 69 P2O5 - 20 LiO2 - 10 AlF3 - 1Tb2O3 (P-Tb1), 59 P2O5 - 20 LiO2 - 10 AlF3 - 10 NaF - 1 Tb2O3 (P-Tb2) and 49 P2O5 - 20 LiO2 - 10 AlF3 - 10 NaF -10KF - 1 Tb2O3 (P-Tb3). All chemical compounds are in powder form with a total mass of 15 grams using the melt-qunching technique at 11000C. To determine the quality of the material, measurements and calculations were made of physical properties including molar mass, density, molar volume, refractive index, Tb3+ ion concentration, Polaron radius, molar refractivity, reflection loss and dielectric constant. Characterizations carried out include FTIR, UV-VIS-NIR Spectrophotometer, Abbe Refractometer, Spectrofluorophotometer. To study the physical properties, the optical properties were examined through their absorption and luminescence spectra. The luminescence spectrum is known by photoluminescence. Characteristic luminescence bands corresponding to electronic transitions of terbium ions were detected under two direct excitations of Tb3+ ions. After 377 nm excitation, the glass sample obtained terbium 5D4→ 7F5 transition at 544 nm indicating green laser. The application of green laser has been investigated with CIE coordinate diagram.
INVESTIGATION OF DOMINANT FREQUENCY AND GROUND AMPLIFICATION BASED ON HVSR MICROTREMOR METHOD IN PANGURURUAN DISTRICT, SAMOSIR Nasution, Nazaruddin; Sirait, Ratni
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.57360

Abstract

In this study, microtremor wave measurements were carried out using the HVSR (Horizontal to Vertical Spectral Ratio) method to identify earthquake vulnerability in Pangururuan District, Samosir, North Sumatra. In this study, measurements were made at 4 points scattered around the area so that the data obtained represented data in the area. Measurement of signal recording data was carried out for 50-60 minutes for each measurement point. Based on the results obtained, the dominant frequency value of the soil is in the range of 2.29 - 12.78 with a very high classification at points RGR1, RGR3 and RGR4 with type I soil classification, namely hard rock, and point RGR2 is classified as low with type IV soil classification, namely soft soil. While the amplification value in Pangururan District is still classified as a low amplification category with an amplification value of <3.
MICROTREMOR ANALYSIS IN DETERMINING LANDSLIDE POTENTIAL IN SEMBAHE VILLAGE, SIBOLANGIT DISTRICT, DELI SERDANG REGENCY Lubis, Rahmadhani; Sirait, Ratni; Lubis, Lailatul Husna
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.60753

Abstract

Sembahe Village is an area that is highly vulnerable to landslides. This is caused by steep topographic conditions and high rainfall. This research is intended to understand the characteristics and distribution of dominant frequencies, amplification factors and seismic vulnerability index on the possibility of landslides. Microtremor measurements were carried out in Hamlet 3 Sembahe Village at 2 location points which were measured using a portable seismograph / Pegasus for 2 hours with a sampling frequency. 100 Hz. Microtremor data was processed using Geopsy software using the Horizontal to Vertical Spectral Ratio (HVSR) method and each parameter was weighted using the Analytical Hierarchy Process (AHP) statistical method in determining potential landslide areas. The results obtained show that the distribution of dominant frequency values (F0) is 5.36 Hz – 5.33 Hz, amplification (A0) is 1.84 – 1.59, seismic vulnerability index (Kg) is 0.63 x 10-3s2 / cm - 0.47 x 10-3 s2/cm. Based on weight analysis using the AHP statistical method, the location point that has the highest potential for landslides is point 1
CALCULATION OF ELECTRONIC PROPERTIES OF LiBX3 (B = Pb AND Sn; X = Br, Cl AND I) CUBIC PHASE BY DENSITY FUNCTIONAL THEORY Sagala, Junaina Sahputri; Sirait, Ratni; Ong, Russell
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.61583

Abstract

Perovskite solar cells utilize perovskite as the active material to convert sunlight into electrical energy. Perovskite is a compound with a crystal structure of ABX₃, where A and B are cations, and X is an anion, usually a halide. Research continues to find perovskites with high efficiency. This efficiency is related to the electronic structure, which can be analyzed using Density Functional Theory (DFT). In this study, the electronic structure of cubic phase LiBX₃ perovskites (B = Pb and Sn; X = Br, Cl, and I) is investigated using Quantum ESPRESSO software. Various parameters such as cut-off energy, k-points, and lattice constants were modified to obtain optimal values. From the optimization results, the band gap, DOS, and PDOS values for the six perovskites were obtained. The resulting band gap energy (Eg) are LiPbBr₃ at 1,71 eV, LiPbCl₃ at 1,87 eV, LiPbI₃ at 1,43 eV, LiSnBr₃ at 0,51 eV, LiSnCl₃ at 0,65 eV, and LiSnI₃ at 0,28 eV. These results show that the band gap energy values increase with the change in atomic radius from Sn to Pb and decrease with the change in atomic radius from Cl, Br to I. The electronic structure calculations of LiBX₃ (B = Pb and Sn; X = Br, Cl, and I) show semiconductor properties that have the potential to be used as light-absorbing materials in perovskite solar cells. This study states that LiBX₃ has great potential in solar cell applications and offers a deep understanding of the relationship between crystal structure and its electronic properties.
VARIATION OF POTATO STARCH AND BAGASSE CELLULOSE ON THE PHYSICAL AND MECHANICAL PROPERTIES OF BIOPLASTICS Sulkha, Amalia; ., Masthura; Jumiati, Ety
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ein.v12i3.62280

Abstract

Bioplastics are ordinary plastics that can be used, but can be decomposed by microorganisms, so they are environmentally friendly. The aim of this research is to determine the characteristics of potato starch and bagasse cellulose bioplastics and to determine variations that produce compositional characteristics with the best quality for making bioplastics using potato starch and bagasse cellulose as basic ingredients. Samples A (75% : 25%), B (50% : 50%), and C (25% : 75%) have different compositions of potato starch and bagasse cellulose. To make bioplastic, magenectic is used for one hour at a speed of 500 rpm and a temperature of 80 °C. The size of the mold is 20 x 20 x 1 cm3, and drying is carried out in an oven at 50°C for 12 hours. This research has several tests, namely physical tests including water absorption tests refers to ASTM D570-98, and the biodegradable test follows SNI 7188.7:2016. Test The mechanism includes the tensile strength test of the SNI 06-1315-2006 testing standard.
GYMNASIUM CALORIE SPECTRUM FLEXIBILITY AND MOBILITY OPTIMIZATION DESIGN Rahman, Rasyad Tanzilur; Solakhudin, Nur Muhammad; Pangyom, Wanudya; Arifin, Zaenal; Afriliani, Nita; Aziz Thohari, Afandi Nur
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/eins.v12i3.62673

Abstract

 This research aims to produce Spektrum Gymnasium which is used as a progress monitoring tool and digital track of sports training that is accurate in building muscle in an efficient time and partners can monitor each customer's muscle-building exercise movements so that the calories wasted can be known, thereby increasing customer satisfaction. The research method begins with discussions with accompanying lecturers and partners. Implementation of activities begins with designing devices, collecting tools and software, and creating outputs in the form of Summit Health tool applications and manuals for using tools and applications. Partner assistance was carried out 6 times. Monitoring and evaluation were conducted to determine developments in using Summit Health tools and the Spectrum Gymnasium application. The sustainability of the Summit Health tool and the Spectrum Gymnasium application as a solution to problems and a guidebook can help in developing tools and applications to calculate calories for consumers independently. The results achieved are in the form of progress reports, final reports, guidebooks, social media accounts, Summit Health tools and Spectrum Gymnasium applications, scientific articles, Summit Health books, IoT-based Spectrum Gymnasium applications, IPR applications and activity publications. Conclusion Spektrum Gymnasium accurately monitors the progress of exercise training in building muscle efficiently. The monitoring feature makes it easier for gym partners to track exercise movements and calories burned, increasing customer satisfaction and exercise results, as well as strengthening customer loyalty and supporting sustainable business growth.
ANALYSIS OF GRANITE ROCK WEATHERING IN THE PARMONANGAN AREA USING LANDSAT 8 SATELLITE IMAGERY Juliani, Rita; Rahmatsyah, Rahmatsyah; Tampubolon, Togi; Halawa, Erniwati; Sari, Silvia Dona; Purba, Rama Yana
EINSTEIN (e-Journal) Vol. 12 No. 3 (2024): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/eins.v12i3.63264

Abstract

 A research has been conducted to analyze the weathering of granite rocks in the Parmonangan area using Lansat 8 satellite imagery which aims to determine the distribution of rocks, weathering processes, and types of rock forming elements in Parmonangan District, North Tapanuli Regency. The method used is using shp geologic map data and Lansat-8 image data processed using Arcgis Map 10.6.1 to determine the distribution of rocks and land cover. XRF is used to identify compounds and rock-forming elements. The results obtained by the rock distribution of the parmonangan area are in the form of the Kluet Formation, Sibolga Complex and Toba Tuff. Land cover in the parmonagan area has differences from 2016 to 2024. Open land in 2024 has increased and the cloud cover obtained has also increased. The rock elements found are Al2O3 (25.31), SiO2 (24.97), K2O (1.56), TiO2 (0.81), Mn2O (30.66), Fe2O3 (4.66), ZrO2, (0.21), Sb2O3 (0.16), and BaO (0.17).
NUMERICAL ANALYSIS OF CONCRETE-FLY ASH AND CONCRETE-OPC IN MULTI- STOREY BUILDINGS DURING EARTHQUAKES Nasution, Habibi Azka; Gea, Mitra Lestari; Nasution, Budiman
EINSTEIN (e-Journal) Vol. 13 No. 1 (2025): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/eins.v13i1.48769

Abstract

OPC-concrete is the most commonly used type of concrete. The production of OPC produces CO2 emissions, which is one of the main causes of climate change and global warming. A recent innovation used as a high-strength concrete admixture is fly ash. Earthquakes pose a serious threat to the safety and stability of high-rise buildings. This study uses a finite difference method computational approach to analyze the seismic behavior of multi-storey buildings using fly ash concrete and opc concrete by utilizing data on stiffness, mass, damping, and earthquake acceleration. Based on the simulation results, the mode shape graphs of fly ash concrete and opc concrete are similar but the vibration frequencies of both are different, where the frequency of fly ash concrete is higher than the frequency of opc concrete. The displacements of the buildings with fly ash concrete and opc concrete still meet the applicable deviation allowance, where the maximum displacements of the buildings are 0.00308 m and 0.00342 m, respectively, while the maximum shear force of both buildings occurs on the first floor, which is 5967.59 N and 5104.78 N, respectively.

Page 28 of 29 | Total Record : 287

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