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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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BIOGAS SYNTHESIS OF COW DUNG WASTE THROUGH FERMENTATION TIME VARIATION PROCESS Siti Khairani Sinaga, Siti Khairani; Masthura; Lubis, Ridwan Yusuf
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.v13i1.56402

Abstract

Biogas is a gas that arises when organic materials, such as animal waste, human waste, or garbage, are soaked in water and stored in a closed or anaerobic place (without oxygen from the air). The purpose of this study was to determine the pH value, temperature, methane content, flame length and fire color in biogas made from cow dung waste. This study used 3 variations of fermentation time, namely 14 days, 21 days and 28 days. Based on the results of the study, it is known that the best fermentation time variation is on day 28 with 63% methane content, pH value 7, temperature 280C, flame duration 41 seconds and reddish yellow flame color.
IDENTIFICATION OF SUBSURFACE STRUCTURES IN LANDSLIDE AREAS IN BRAND DISTRICT Fadhilah, Nurul; Kadri, Muhammad; Tampubolom, Togi
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.v13i1.60845

Abstract

A research has been conducted on the identification of subsurface structure of landslide area using geoelectric and geomagnetic methods in Pangambatan Village, Merek District, Karo Regency. The research aims to determine the subsurface structure, causes of landslides and indicators of landslides. Geo-electrical measurements were taken using ARES-G4 v4.7 (Automatic Resistivity System) and GPS (Global Position System) with three passes. Each track has a total of 16 electrodes with a distance of 5 meters for each electrode. The geomagnetic method uses a PPM (Proton Procession Magnetometer) type GSM-19T. Data collection with the number of points obtained 25 measuring points. The results showed that the subsurface structure using geoelectricity contained alluvium, sand, gravel, silt, groundwater, sandstone, limestone and andesite rock types. The resistivity value of the first track ranges from 500-2000 Ωm, the second track is 50-4,500 Ωm, and the third track is 200-1,500 Ωm. Based on geomagnetic research, there are rock types with susceptibility values of sandstone (0.0010; 0.0015) cgs, limestone (0.0030) cgs and clay (0.0020) cgs. The causes of landslides in the research location are sand, gravel, alluvium and clay as landslide-carrying materials, while sandstone and limestone as sliding planes. Soil indicators that cause landslides based on geoelectric results are the second track with a difference of two layers of contrasting resistivity values. And geomagnet results with low susceptibility values.
CALCULATION OF ELECTRONIC PROPERTIES AND MECHANICAL PROPERTIES OF CUBIC PHASE CH3NH(3)PbCl3 USING DENSITY FUNCTIONAL METHOD Ong, Russell; Sagala, Junaina Sahputri
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.v13i1.63453

Abstract

Organic-inorganic hybrid halide perovskite-based solar cells such as CH3NH3PbCl3 are known to have many advantages such as low price, simple preparation process and high photoelectric conversion rate. Therefore, we performed theoretical calculations to determine the electronic properties and mechanical properties of CH3NH(3)PbCl3material with space group p3m3 with bulk system in this study. Both properties are calculated by the Density Functional Theory (DFT) method through Quantum ESPRESSO software. The electronic properties discussed include electronic band structure, density of states (DOS) curve, and projected density of state s (PDOS) curve, while the mechanical properties include elasticity constant (Cij), limb modulus (B), Young's modulus (E), shear modulus (G), and Poisson's ratio (ʋ). To determine these properties, the optimum lattice constant must be achieved through optimization of k-points and cut-off kinetic energy. The results show that the value of the lattice gap is 2.49 eV, and C11, C21, C44, limbal modulus, Young's modulus, shear modulus, and Poisson's ratio are 143.83 GPa, 21.22 GPa, 28.24 GPa, 62.09 GPa, 101.75 GPa, 41.47 GPa, and 0.23 GPa, respectively. This shows that the cubic phase CH3NH3PbCl3 waste material is mechanically stable which also has great potential as a perovskite semiconductor material.
EXPERIMENTAL STUDY OF BORATE-BASED GLASS MEDIUM MATERIAL AND HUTA GINJANG QUARTZ SAND THROUGH MELT-QUENCHING TECHNIQUE Pangabean, Jonny Haratua; Hutahaean, Juniar; Sihombing, Luli Warty; Doloksaribu, Maryati Evivani; Rajagukguk, Juniastel
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.v13i1.64965

Abstract

This research aims to produce a glass material based on quartz sand and borate compounds that can later be applied as a host matrix of rare earth ions as optical amplifiers. The research stages began with exploring quartz sand from Huta Ginjang, cleaning, grinding using a ball-mill and mixing with several other compounds namely Boron oxide (B(2) O3), barium oxide (BaO) and sodium oxide (Na2) O. The calculation and weighing process is carried out to obtain the mass of each compound to be used. The composition of each compound is shown through the chemical formula (x)Quartz sand + (60- x)B(2)O(3)+ 10BaO + 30Na2O (where x = 0; 2.5; 5; 10; 15; 20 mol%). The next step is the melting and molding process using the melt-quenching method. Through this experiment, a homogeneous and more transparent glass medium with optimum composition for each former and modifier compound was obtained.
IMPROVEMENT OF BIOPLASTIC CHARACTERISTICS FROM TAPIOCA WASTE USING TITANIUM DIOXIDE AS A FILLER Sipayung, Esther Permata; Doloksaribu, Maryati Evivani
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.v13i1.65201

Abstract

The use of conventional plastics that are difficult to decompose so that the accumulation of plastic waste can cause various problems in the environment. One way to overcome this problem is to replace petroleum-based plastics with other materials that have similar characteristics but are made from renewable materials and have biodegradable properties so that they can decompose naturally in a relatively faster time. Cassava is a polysaccharide containing starch with a high amylopectin content but lower than sticky rice, namely 83% amylopectin and 17% amylose. Tapioca dregs are waste that rots quickly if not processed further. Therefore, efforts are needed to utilize tapioca waste. The addition of Titanium Oxide is very suitable as an antibacterial agent because it is economical, has good mechanical stability, thermal stability, absorbs ultraviolet light, has a photocatalytic effect, and has a large surface area, especially in the manufacture of Bioplastics. Titanium oxide as a filler in bioplastics from tapioca waste can improve the characteristics of bioplastics. In this study, the water resistance value of biodegradable plastics was the highest, namely 47.73%. Titanium Oxide as a filler affects the tensile strength of bioplastics from tapioca waste. The highest tensile stress was obtained at a percentage of 0.8307 MPa, the highest strain was obtained at a percentage of 0.0951%, and the highest modulus of elasticity was 11.4411 MPa. In the biodegradability test with a value of 47.77% with the addition of titanium oxide filler, it meets the requirements to be used as a basic material for biodegradable plastic.
TOPOGRAPHIC MAPPING OF SLOPES IN LANDSLIDE PRONE AREAS USING THE SCHLUMBERGER CONFIGURATION GEOELECTRICS TECHNIQUE Situmorang, Howard; Nasution, Habibi Azka; Nasution, Budiman; Aningsih, Sri; Ummi, Shofia
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.v13i1.65332

Abstract

Landslides in Lembang in 2020-2021 were influenced by intense heavy rainfall. The surface contours in the village are generally in steep surface conditions with varying slope angles. The purpose of this study was to determine the surface contour in two dimensions by using the geoelectric method with Schlumberger configuration. The first stage was carried out by recording data on 5 tracks with 3 parallel tracks up to 75 , one track intersecting the other track area up to 60 and one track next to the landslide at 52.5 . The results showed that the resistivity of the rocks varied between 0.465-1952 . Interpretation of rock 0.465-21.5 as clay and sand, 22-146 as sandstone, dry gravel, 156-380 as andesite, basalt and 389-1952 as granite, diorite, limestone. The contrasting differences in the variation of the values on each track are known as slip planes. Slip planes have been found on 5 tracks with depths ranging from 6 to 12 m. The results of the 2-dimensional surface modelling that has been carried out show that the research area has the potential for landslides
DETERMINATION OF FAULT PATTERNS AND SUBDUCTION PATTERNS IN THE NORTH SUMATERA REGION USING THE DOUBLE DIFFERENCE METHOD (HYPODD) FOR THE 2023 EARTHQUAKE Kencana, Mudatsir; Lailatul Husna Lubis; Ratni Sirait
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.v13i1.65334

Abstract

Earthquakes are caused by the meeting of the two plates, namely the Indo-Australian plate and the Eurasian plate, the meeting of these two plates can also cause the occurrence of fault fault planes and subduction subduction with different depth levels. This study was conducted to see how the pattern of the fault fault plane and subduction subduction pattern that became one of the parameters to determine the depth of the epicentre after and before the relocation process, using the hypodd program format and ph2dt output results through anaconda prompt in the double difference method process, so that the results obtained from the relocation of the earthquake hypocenter in 196 earthquake events were only 127 earthquake events that could be relocated. Based on the relocation results using the double difference method, it can also be seen that earthquake events are more in the fault pattern with a depth level of 1-50 km, compared to the subduction pattern with a depth level of 60-200 km which is not too many earthquake hypocentres, so it can be said that the earthquake event in the North Sumatra region in 2023 is included in the shallow earthquake category.

Page 29 of 29 | Total Record : 287

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