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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 EFFECT OF CONCRETE DOPING USING PALM PALM BOILER ASH AND SUPERPLASTICIZER ON THE STRENGTH OF K-300 CONCRETE Surya Kurniawan Hutabarat; Nurdin Siregar
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: 10.24114/2aejef67

Abstract

Concrete is a favorite reinforcement material that is commonly used in Indonesia because it has superior properties compared to other materials. Some of the advantages of concrete include economical prices, cheap manufacturing processes, heat resistance, strong strength and materials that are easy to obtain. Every year the number.The population in Indonesia is increasing, which causes high demand for building materials, in this case there is a shortage of mixed materials for making concrete. This concrete synthesis research was carried out to determine the effect of a mixture of palm oil boiler ash and superplasticizer on concrete strength, water absorption capacity and concrete morphology. The concrete is made in the shape of a cube with dimensions of 15 cm x 15 cm x 15 cm according to the SNI 7394(2008) k-300 standard. The mixture variations used are ABKS 100 Mesh (0%, 1.5%, 3%, 4.5% and 7.5%) and superplasticizer 0% and 2%. After a period of 28 days the concrete was tested using the compressive strength test method using existing procedures. The highest compressive strength was in a mixture composition of 7.5 ABKS and 2% SP of 34.55 Mpa and the lowest compressive strength was in concrete without a mixture of 20. 88 Mpa. With the highest water absorption capacity of 0.52% in the unmixed concrete variation and the lowest in the 7.5 ABKS and 2% SP mixture of 0.27%. EDX analysis results show that unmixed concrete contains the highest element of 32.49 % Calcium (C) And in the highest quality concrete the mixture of boiler ash and superplasticizer with the highest element of Silica (Si) is 20.55%. The compressive strength results exceed the SNI provisions that have been set. The higher the addition of the mixture composition, the higher the compressive strength concrete and the concrete's absorption capacity is getting lower.
ANALYSIS AND CHARACTERIZATION OF THE INDICATOR ELECTRODE MEMBRANE PVA-ENZYME/GA/PANI-BENZENE SULFONATE ACID/ PVC-KTPCLPB-O-NPOE Henni Sulastri BR Sinaga; Abd Hakim S
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: 10.24114/00ss7v40

Abstract

This research aims to determine the characteristics of indicator electrode membranes using XRD, SEM-EDS and FTIR testing. Differences in the composition of the urease enzyme will affect the diffraction spectrum pattern of the indicator electrode and the use of a conductive polymer, namely PANi, can increase the intensity of the crystal diffraction pattern. The method used is the potentiometric biosensor method with the urease enzyme immobilization technique. The indicator electrode membrane is composed of four layers, namely PVA-enzyme/GA/PANi-Benzene Sulfonic Acid/PVC-KTpClPB-o-NPOE. Based on XRD testing, sample II has the highest intensity of 39170 at 2θ = 24.07°; while sample II has an intensity of 8450 a.u. The resulting diffraction pattern shows that the electrode membrane is a polymeric material as indicated by the presence of crystalline and amorphous patterns. Based on SEM-EDS testing, it shows that the morphological structure of sample I has fewer pores with the tungsten element as the working point, namely 81.98 wt.% and the C element 9.99 wt.% compared to sample II with the tungsten element as the working point. namely 65.60 wt.% and element C 16.41 wt.%. FTIR results show that the transmittance value increases due to the use of polymer in the third layer, namely PANi, so that the best electrode membrane is PVA-Enzyme 1 drop/GA/PANi-Benzene Sulfonic Acid/PVC-KTpClPB-o-NPOE 61% with the highest transmittance in the wave number range 1423.84 cm-1 “ 2914.77 cm-1.
MORPHOLOGICAL AND THERMAL PROPERTIES STUDY OF PCL BIOCOMPOSITES WITH NANOCELLULOSE FILLER FROM RICE HUSK USING PCLacac COMPATIBILIZER AS  MATERIAL CANDIDATE FOR BONE SCAFFOLDS Muhammad Yusuf; Yossie Juliastri Napitupulu; Eddiyanto Eddiyanto; Innayah Wulandari; Winsyahputra Ritonga
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: 10.24114/8phs4e72

Abstract

Biocomposites from poly(ε-caprolactone) (PCL) matrix with nanocellulose filler are materials that have been developed for biomedical applications, such as scaffolds, tissue engineering, implants, and wound dressings. The PCL matrix is flexible and biocompatible. Meanwhile, the rice husk nanocellulose filler is environmentally friendly, renewable, and abundantly available in Indonesia. However, the differences in the hydrophobic properties of PCL and the hydrophilic properties of nanocellulose cause low interfacial adhesion, so a compatibilizer is needed to improve the compatibility of the two phases. This study aims to examine the effect of adding short-chain PCL (PCLacac) as a compatibilizer. The mixing of the PCL matrix, nanocellulose filler, and PCLacac compatibilizer used the solvent casting method. The characterization results using Scanning Electron Microscopy (SEM) showed that the addition of PCLacac can improve interfacial adhesion between the matrix and filler, characterized by a more even filler dispersion and reduced agglomeration. On the other hand, thermogravimetric analysis (TGA) analysis showed that the addition of 3% PCLacac resulted in an increase in decomposition temperature, which indicates an increase in thermal stability due to better interfacial interactions between the matrix and filler. Thus, the addition of PCLacac plays an effective role in improving the morphological structure and thermal resistance of PCL/rice husk nanocellulose biocomposite, so it has the potential to be developed as a biocomposite material in biomedical applications including bone scaffolds.

Page 31 of 31 | Total Record : 303

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