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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 303 Documents
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The IDENTIFIKASI BATUAN BAWAH PERMUKAAN DAERAH PANAS BUMI TAPANULI UTARA MENGGUNAKAN METODE HORIZONTAL TO VERTICAL SPECTRAL RATIO Iswari, Wita; Juliani, Rita
EINSTEIN (e-Journal) Vol. 14 No. 1 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/b1bd4b60

Abstract

The research aims to identify subsurface rocks in the geothermal area of North Tapanuli using the Horizontal to Vertical Spectral Ratio (HVSR) method. The HVSR method analyzes the spectral response of microtremor waves to obtain dominant frequency parameters (f₀) and amplification factors (A₀) that can describe the depth and type of subsurface layers. Data were collected in four locations, namely Partali Toruan village, Parbubu village, Situmeang Hasundutan village, and Simasom Toruan village. The analysis results show that the f₀ values in Partali Toruan Village, Situmeang Hasundutan Village, and Simasom Toruan Village indicate the presence of breccia, andesite, and basalt bedrock in the subsurface and function as cover rock in the geothermal system. Parbubu Village produces f₀ values that indicate an alluvium sedimentary layer. The shear wave velocity (Vs) profiles obtained show a stratigraphic structure typical of volcanic areas, with a significant increase in Vs with depth indicating a transition from medium soil to hard rock.
BIOSENSOR ELEKTROKIMIA BERBASIS POLIMER CETAK MOLEKULER (MIP) DAN CETAK PERMUKAAN UNTUK DETEKSI PENYAKIT INFEKSIUS: Tinjauan Kemajuan Terkini dan Tantangan dalam Pengembangan Biosensor Elektrokimia Berbasis MIP untuk Deteksi Patogen Hudaiby, Nazwa; Ritonga, Winsyahputra
EINSTEIN (e-Journal) Vol. 14 No. 1 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jqca2t05

Abstract

Electrochemical biosensors have emerged as promising tools for the diagnosis of infectious diseases due to their high sensitivity, rapid response, and low cost. The use of molecularly imprinted polymers (MIPs) and surface imprinted polymers (SIPs) as robust and selective artificial receptors has gained significant attention. This review summarizes the recognition mechanisms between MIPs/SIPs and various infectious disease biomarkers, including small molecules, microbial toxins, viruses, and bacterial or fungal cells. Different MIP/SIP fabrication techniques such as electropolymerization, coating, and micro-contact imprinting are discussed. The review also highlights clinical applications of MIP/SIP-based biosensors for detecting specific pathogens, such as HPV, HIV, E. coli, and Zika virus. Key challenges such as enhancing sensitivity and selectivity, as well as the future potential of integrating artificial intelligence in biosensor design, are also addressed
The Effect of Grammage on Bulk in A-Grade Printing Paper Based on Taro Skin and Oil Palm Fronds Putri Nadila; Ety Jumiati; Miftahul Husnah
EINSTEIN (e-Journal) Vol. 14 No. 1 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/hgh4na76

Abstract

The use of wood as the main raw material for paper production causes environmental problems such as deforestation. This study aims to analyze the physical characteristics of paper made from taro skin and oil palm fronds through the parameters of grammage and bulk. Grammage and bulk are important parameters in determining the quality of printing paper A according to SNI 7274:2008. The composition variations used were samples A (60%:40%), B (40%:60%), and C (20%:80%). The results show that the lowest grammage value is 79 g/m2 in the 20%:80% variation and the highest grammage value is 90 g/m2 in the 60%:40% variation. For bulk testing, the lowest value was 1.11 cm3/g in the 20%:80% variation and the highest bulk value was 1.46 cm3/g in the 60%:40% variation. All samples met the SNI 7274:2008 standard for A-grade printing paper, with a grammage limit of 50-100 g/m2 and a maximum bulk of 1.5 cm3/g. Increasing the proportion of oil palm fronds reduced the grammage but increased the bulk. This study proves the potential of taro skin and oil palm fronds as raw materials for environmentally friendly paper.
ANALYSIS OF CREPER MACHINE UTILIZATION IN CRUMB RUBBER PRODUCTION BASED ON BLANKET THICKNESS DISTRIBUTION AT PT. PANTJA SURYA Purba, Reza Hazly Al’Udlu; Siregar, Rohimah Nurul Huda; Alysha Tasya Aulia; Situmorang, Tiur Nauli; Siregar, Nisa Zahra Gustiani; Nasution, Budiman; Situmorang, Howard; Nasution, Habibi Azka
EINSTEIN (e-Journal) Vol. 14 No. 1 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/301n3m09

Abstract

Creper machines are vital in crumb rubber processing for reducing material thickness and ensuring blanket quality. This study provides a quantitative physical analysis of five creper machines at PT. Pantja Surya, focusing on how pressure force and maintenance schedules correlate with blanket thickness distribution. Primary data were collected through field observations and technical equipment specifications, which were subsequently analyzed using the Python programming language to calculate mechanical parameters, including the reduction ratio, roll-material contact length (Lp), and estimated compressive force (F). The results indicated that the maximum mechanical load was concentrated on Creper 1, with an estimated compressive force of 867.85 kN, correlating with the maximum contact length of 0.177 m. An anomaly was observed in Creper 3, which functions as a transition stage without thickness reduction to stabilize the material's viscoelasticity. The distribution of compressive force gradually decreases in Crepers 4 and 5 (382.57 kN and 352.28 kN, respectively), consistent with a more controlled reduction process. This analysis demonstrates that units subjected to higher compressive forces require shorter maintenance intervals (120 hours) compared to units with lower loads (160 hours). Consequently, these findings establish a framework for implementing load-based predictive maintenance to enhance operational efficiency in the industry.
IDENTIFICATION OF FAULTS AND SLIP DIRECTIONS THROUGH A STUDY OF FOCAL MECHANISMS IN NORTH SUMATRA (2018-2024) Ayu Lestari, Maysa Indah; Sirait, Ratni; Lubis, Lailatul Husna
EINSTEIN (e-Journal) Vol. 14 No. 1 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ps22ej09

Abstract

North Sumatra is located in the Ring of Fire zone, making it prone to earthquakes due to the convergence of the Indo-Australian and Eurasian plates, which form the 390 km long Sumatra Fault. This study aims to analyze the focal mechanism of earthquakes in North Sumatra during the period 2018-2024 using data from the Global Centroid Moment Tensor (GCMT). The analysis focuses on determining the type of earthquake mechanism, fault plane orientation, and slip direction and characteristics based on 21 earthquake events with magnitudes ranging from 4.8 to 5.4 Mw, analyzed using parameters such as location, time, depth, and nodal plane orientation. The results of the study indicate that earthquakes occurring in North Sumatra are dominated by strike-slip faults with horizontal movement. The orientation of the fault planes generally points northwest-southeast (NW-SE) and northeast-southwest (NE-SW), consistent with the characteristics of the Sumatra Fault and its segments, such as Renun, Toru, Barumun, and Angkola. Most of the earthquakes occurred at shallow to intermediate depths, posing a potential risk of damage in densely populated areas. These findings are expected to enhance regional geotectonic understanding and support earthquake disaster mitigation strategies in North Sumatra.
Sistem Otomatisasi Pakan Ikan Lele dan Pemantauan Kualitas Air Menggunakan Platform Arduino Lailatul Husna Lubis; Mulkan Iskandar Nasution; Shiti Indriani
EINSTEIN (e-Journal) Vol. 14 No. 2 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/2a6cmk19

Abstract

The Arduino-based aquaponics automation control system for catfish farming is designed to optimize catfish rearing in urban environments by using various sensors and automation components. This system utilizes a pH sensor, temperature sensor, and TDS sensor to monitor water quality in real-time, as well as an ultrasonic sensor to measure the water level in the pool. Data from these sensors is used to regulate and control the water pump system, which functions as a means of recirculating water to keep it clean and maintain its quality. With the results, the TDS sensor value has a range of 327.75 – 325.22 ppm. The pH sensor value has a range of 7.09 – 7.05. The temperature sensor value has a range of 29.94 – 30.00 ℃. The value of the ultrasonic sensor by measuring the water level of the fish pond with a value obtained is 28 cm. Apart from that, this system is equipped with a servo motor which is used to feed the fish automatically, ensuring that the fish get food on time, feeding once a day at 17:00 WIB with a total feed output of 188 gr for 5 seconds with the servo angle being 90°. All data generated from these sensors is stored in a structured manner in memory for long-term analysis and monitoring purposes. Implementation of this control system shows effective results in raising catfish in urban settlements. With automation and continuous monitoring, this system not only simplifies aquaponics management but also increases efficiency and sustainability in dense urban environments. This system offers a practical and innovative solution to the problem of maintaining aquaponics in limited areas, as well as contributing to the development of sustainable urban farming technology
A DFT STUDY ON THE PHONON PROPERTIES OF PEROVSKITES ASnCl3 (A = K, Rb, AND Cs) Russell Ong; Dinda Fadhilah Nur Azimmi
EINSTEIN (e-Journal) Vol. 14 No. 2 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ra9zef54

Abstract

Inorganic perovskites such as ASnCl3 (A = K, Rb, and Cs) are widely used in solar cells because they are known to have many advantages, such as being easily obtainable and having high efficiency. Therefore, in this study, we conducted computational study to determine the phonon properties of ASnCl3 perovskites (A = K, Rb, and Cl) with a pm3m space group in a bulk system. These properties were calculated using density functional theory (DFT) through the Quantum ESPRESSO program. The phonon properties discussed are phonon density of states (PHDOS) and phonon dispersion. In addition, the dielectric constant was also calculated because the code is straightfoward in the dynamical matrix process. To calculate the phonon properties, the optimum lattice constant must be achieved through k-point optimization and kinetic energy cut-off. The results show that the highest phonon distribution in KSnCl3, RbSnCl3, and ClSnCl3 perovskites is at frequencies of -68.52 cm-1, -55.37 cm-1, and 55.83 cm-1, respectively. The presence of phonon distribution or phonon dispersion curves at negative frequencies explains that ASnCl3 perovskites (A = K, Rb, and Cl) are unstable perovskites. Nevertheless, the dielectric constants of these three perovskites are quite good, making them very promising as active materials for perovskite solar cells. When compared to the reference static dielectric constants, the obtained values are consistent with the Lyddane‒Sachs‒Teller relation.
EFFECT OF DURATION OF ZnO PROTOTOTYPE DYE SENSITIZED SOLAR CELL LAYERS OF FAMBIR (UNCARIA) FRUIT EXTRACT AS A PHOTOSENSITIZER Rahmatun Rahma Toyyibah; Abdul Rais
EINSTEIN (e-Journal) Vol. 14 No. 2 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/hvyt7136

Abstract

DSSC research using organic dyes has been carried out by fabricating solar cells using dyes from gambir plants. The stages of this research are the manufacture of gambir fruit dye as a photosensitizer. This study aims to determine the effect of DSSC performance due to variations in soaking time. XRD test results show crystal sizes of 28.44536 nm, 7.66144 nm, 8.3061 nm, 2.93336 nm, and 19.97532 nm. SEM characterization of the ZnO layer on FTO glass looks uneven due to the difficulty of regulating the stability of the layer using the Doctor Blade method. UV-Vis characterization with a wavelength of 200-800 nm shows the results that the dye solution can work in invisible light to visible light with an absorbance value of 5.254 a.u. The current and voltage values in the immersion variation will be accumulated to determine the efficiency value of the DSSC. The efficiency values for 14 hours, 16 hours, and 18 hours are 0.0146%, 0.0192% and 0.0692%.
ANALYSIS OF THE INFLUENCE OF SNAKEFRUIT SKIN ASH ON THE COMPRESSIVE STRENGTH OF K-175 CONCRETE Nova Syafitri Siregar; Motlan Motlan
EINSTEIN (e-Journal) Vol. 14 No. 2 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/rkvddb08

Abstract

Research has been carried out on K-175 concrete with a mixture of snakefruit bark ash with the aim of determining the effect of snakefruit bark ash on the mechanical properties of K-175 concrete. The test object used was a cube measuring 15 cm x 15 cm x 15 cm with standardization SNI-7394-2008 with quality K-175 with a cement ratio of 1: 2.3: 3.1 with FAS 0.6. The mechanical properties testing carried out was compressive strength testing and determining the crystal structure and filler phases of the concrete after soaking for 28 days and drying for 24 hours. Based on the research results with a mixture of snake fruit ash (0%, 0.5%, 1%, 2%, 4%) the average compressive strength test results were 18.11 Mpa, 17.21 MPa, 17.02 MPa, 20, respectively. 23 MPa, and 16.80 Mpa. Where the test is carried out after the concrete is 28 days old. From the results of the compressive strength test, the concrete experienced an insignificant decrease in compressive strength with each addition of snakefruit bark ash, but the compressive strength increased with the percentage of snakefruit bark ash (2%). The maximum compressive strength result with a mixture of snakefruit bark ash was 20.23 Mpa. Based on the test results and X-Ray Diffraction analysis results, it shows that the concrete samples containing silica are mostly amorphous, it can be seen in the graphic image that there is only a very small amount of X-ray diffraction which has sharp and angular peaks, this shows that the crystalline content is getting smaller thus most of the contained in the sample is amorphous.  
EFFECT OF PARTIAL CEMENT REPLACEMENT RATIO WITH CHICKEN BONE ASH ON COMPRESSIVE STRENGTH AND POROSITY MORTAR Thresha Sepriany Nainggolan; Karya Sinulingga
EINSTEIN (e-Journal) Vol. 14 No. 2 (2026): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/24ec9j66

Abstract

This study evaluates the effect of partial cement substitution with chicken bone ash on the compressive strength and porosity of mortar. Mortar is a crucial adhesive material in construction that determines the strength and durability of structures. The mortar mixtures were prepared by replacing part of the cement with chicken bone ash at variations of 0%, 3%, 6%, and 9% by weight of the cement according to SNI 03-6825-2002. Cube-shaped mortar samples measuring 5x5x5 cm were tested for compressive strength after 28 days, and porosity was measured using the gravimetric method referring to Archimedes' principle. The compressive strength test results at 0% variation were 10.45 MPa, at 3% variation were 14.75 MPa, at 6% variation were 12.52 MPa, and at 9% variation were 5.52 MPa. The porosity results for the 0% variation were 2.1%, for the 3% variation were 3.2%, for the 6% variation were 3.2%, and for the 9% variation were 4.8%. It is concluded that high porosity can reduce the material's strength. The results of XRF testing on chicken bone ash calcined up to 800°C for 4 hours showed the composition of several chemical elements. Of the elements detected, CaO dominates with a content reaching 61.18%.

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