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All Journal Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics JURNAL FISIKA JOURNAL ONLINE OF PHYSICS JPSE (Journal of Physical Science and Engineering) Journal of Physics and Its Applications JURNAL EKSAKTA PENDIDIKAN (JEP) KONSTAN - JURNAL FISIKA DAN PENDIDIKAN FISIKA JURNAL PENDIDIKAN TAMBUSAI GERVASI: Jurnal Pengabdian kepada Masyarakat Kappa Journal Inovasi Pendidikan: Jurnal Pendidikan Gravitasi: Jurnal Pendidikan Fisika dan Sains Jurnal Fisika dan Terapannya Jurnal Pendidikan, Sains, Geologi, dan Geofisika (GeoScienceEd Journal) Pillar of Physics Education : Jurnal Berkala Ilmiah Pendidikan Fisika Pillar of Physics: Jurnal Berkala Ilmiah Fisika JRFES Journal of Climate Change Society Uranus: Jurnal Ilmiah Teknik Elektro, Sains dan Informatika
Letmi Dwiridal
Unknown Affiliation
Agriculture, Biological Sciences & Forestry Humanities Astronomy Biochemistry, Genetics & Molecular Biology Chemistry Computer Science & IT Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Environmental Science Languange, Linguistic, Communication & Media Materials Science & Nanotechnology Mathematics Physics Social Sciences Other

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Analisis Momen Tensor dan Mekanisme Fokus Gempa di Sumatera Barat Menggunakan Metode Inversi Waveform Putri, Zakiah Putri; Syafriani; Akmam; Letmi Dwiridal
JFT : Jurnal Fisika dan Terapannya Vol 11 No 1 (2024): JUNI
Publisher : Universitas Islam Negeri Alauddin Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24252/jft.v11i1.42926

Abstract

Analysis of the tensor moment and focal mechanism of an earthquake aims to determine the value of the tensor moment that represents the direction of the force that causes the earthquake and the focal mechanism that describes the characteristics of the fault motion that causes the earthquake. Analysis of the tensor moment and focal mechanism is carried out using the waveform inversion method. The waveform inversion method is an inversion method that utilizes the P-wave arrival time and is estimated with a Green's function involving three seismogram components. The data used in this study are ten earthquake data in the West Sumatra region in 2007-2022 whose earthquake sources are in the Sumatra fault zone with earthquake strength ≥4.9 Magnitude. The results of this study obtained a range of tensor moment values, namely M11 = -2.595 to -4.555, M22 = 1.743 to 4.476, M33 = 0.853 to 0.079, M12 = 6.258 to -4.814, M31 = 1.241 to 0.719, M32 = 0.530 to -1.436, and the results of the focus mechanism obtained are strike-slip patterns.
Compressive Strength Analysis of Mortar Made from Volcanic Sand in Nagari Aia Angek Based on Magnetic Mineral Content Amirullah, Fajar Fikri; Hamdi, -; Dwiridal, Letmi; Amir, Harman; Syafriani, -; Ratnawulan, -
PILLAR OF PHYSICS Vol 17, No 1 (2024)
Publisher : Department of Physics – Universitas Negeri Padang UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/15247171074

Abstract

Mortar is a binder or adhesive with a standard viscosity of ingredients (water, cement, and sand). Mortar made has strength, mortar strength is measured using Cement Compression testing machine. Sand in mortar making contains magnetic minerals such as magnetite (Fe3O4) or Fe2+3Fe+2O4-2, hematite mineral (α-Fe2O3) which will be measured for magnetic susceptibility value using Bartington Magnetic Susceptibility Meter Sensor Type B (MS2B). To determine the concentration of magnetic minerals and their relationship with mortar compressive strength, the rock magnetism method was used. Measurement of sand samples of Kamumuan River, Sungai Limau District using Bartington Magnetic Susceptibility Meter Sensor Type B (MS2B) by categorizing sand into 3 treatment, namely Addition of magnetic minerals (PTM) with χLF value 3863.3 x 10-8m3/kg and χFD (%) 0.72, reduction of magnetic minerals (PKM) with χLF value 1920 x 10-8m3/kg and χFD (%) 0.79, normal magnetic minerals (PM) with χLF value 2334.7 x 10-8m3/kg and χFD (%) 0.62. The sample has a grain type that is almost no superparamagnetic grain and has antiferromagnetic properties. Samples grouped by treatment were made into mortar and tested using a cement compression testing machine with the results of mortar compressive strength, namely ATM of 49.4 Kg/cm², AKM of 46.6 Kg/cm², and AM 52.3 Kg/cm². Based on the analysis conducted, the magnetic minerals contained in the sand affect the results of the compressive strength of the mortar, the higher the susceptibility value in the sand, the stronger the compressive strength of the mortar
Review Analysis of Animated Test Questions Towards Understanding Concepts in Physics Learning Sari, Nurul Fadillah; Mufit, Fatni; Hidayanti, Hidayanti; Dwiridal, Letmi
KONSTAN - JURNAL FISIKA DAN PENDIDIKAN FISIKA Vol 8 No 02 (2023): KONSTAN (Jurnal Fisika dan Pendidikan Fisika)
Publisher : Universitas Islam Negeri (UIN) Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20414/konstan.v8i02.201

Abstract

This study aims to (1) Analyze the application used for making animated test questions. (2) Analyzing the use of animated test questions based on education level. (3) Analyzing the use of animated format test questions based on physics learning materials. (4) Analyzing the use of animated test questions on students' understanding of physics concepts. This study uses a systematic review method using 16 national and international journal articles from 2010-2022. The results of this study showed that: (1) The application used to make test questions in animation format is very large, but Macromedia Flash is more often used. (2) Animation test questions are widely applied or used at the Senior High School level. (3) For material in physics learning, animated test questions are more often applied to the concept of light refraction. (4) Animation test questions can help students to improve their understanding of concepts. The study results show that the animated format test questions affect students' conceptual understanding. However, in reality, when carrying out the test, the format of the questions presented is still in the form of a paper, and a test is in the form of an arguments. Teachers do not know how the influence of the use of animated test questions on students' understanding of concepts, as well as what applications can be used in making animated test questions
Microclimate Characteristics in Mangrove Forest Areas in Padang City Aditio, Rama; Yendri Sudiar, Nofi; Dwiridal, Letmi; Amir, Harman
Journal of Climate Change Society Vol. 1 No. 2 (2023)
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/jccs/Vol1-iss2/17

Abstract

Mangrove forest microclimate is the climatic conditions that occur in mangrove forests. The research aims to determine the conditions and characteristics of the microclimate (air temperature, air humidity and light intensity) in the mangrove forest area. The research location was chosen in the Taluak Buo mangrove forest area because the conditions and characteristics of the microclimate are not yet known. The data used is prime data obtained from direct measurements in the field. Measurements of several weather elements were carried out three times, namely in the morning (07.00-08.00 WIB), in the noon (12.00-13.00 WIB), and in the afternoon (17.00-18.00 WIB) for 7 days at three observation points using an anemometer instrument. The results obtained from this research in the Taluak Buo mangrove forest area in the Bungus Teluk Kabung sub-district are an average daily air temperature of 26.94°C in the forest, 27.94°C at the position on the edge of the forest and 28.6°C at outside the forest. The average difference in air temperature between inside the forest and outside the forest is between 1,22-2,14°C. On the other hand, the difference in air humidity is 5-6%. The average difference in sunlight intensity between inside the forest and outside the forest is between 3.923,44-22,462,66 lux. The air temperature and intensity of sunlight inside the forest is lower than at the edge and outside the forest, which is inversely proportional to the higher air humidity inside the forest.
The Effect of Chemical Fertilizers on The Magnetic Susceptibility Value and Soil Fertility of Paddy Soils in Surantih, Kabupaten Pesisir Selatan Maidani, Delvi Putri; Rifai, Hamdi; Dwiridal, Letmi; Mufit, Fatni
JPSE (Journal of Physical Science and Engineering) Vol 8, No 1 (2023): JPSE (Journal of Physical Science and Engineering)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um024v8i12023p052

Abstract

Pesisir Selatan is a district where population depends on agriculture such as lowland rice. The rice seeds used were IR66. Efforts to improve the quality of Paddy soils seeds are fertilizing with chemical fertilizers. Chemical fertilizers used are Urea, KCL and Phonska. Continuous and excessive use of fertilizers will cause a decrease in the level of soil fertility due to the reaction between fertilizer minerals and soil minerals which also affects the magnetic susceptibility value. Based on these problems, further research was carried out to see the difference in the magnetic susceptibility value of paddy soils to the use of chemical fertilizers using the rock magnetism method with magnetic susceptibility parameters. The results showed that the paddy soil before and after being planted with rice seeds using chemical fertilizers decreased and increased the value of magnetic susceptibility due to the reaction between mineral fertilizers and soil minerals and waterlogging during the cultivation process. Meanwhile, the paddy soil before and after planting rice seeds that did not use chemical fertilizers decreased the magnetic susceptibility value quite far due to the absence of other mineral additions in the paddy soil such as chemical fertilizers.
PGA Estimation of 346 Points in West Sumatra based on Earthquakes Scenario in West Pasaman with Si and Midorikawa Formula Ramadhan, Wahyu; Syafriani, Syafriani; Fauzi, Ahmad; Dwiridal, Letmi
Journal of Physics and Its Applications Vol 6, No 2 (2024): May 2024
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v6i2.20795

Abstract

There was a destructive earthquake on February 25, 2022, at 08:39:29 WIB with a magnitude of 6,1 Mw that struck western Sumatra with an epicenter on land, and was located on a blind fault. The impact of the earthquake was felt quite widely in all Regencies/Cities in West Sumatra with an intensity of IV – VIII MMI. The earthquake caused damage, an estimated 6627 houses, 70 mosques, 41 offices, 208 schools, 25 medical infrastructure and 5 bridges. Therefore, it is necessary to conduct research in the province of West Sumatra on PGA using the Si and Midorikawa method and intensity with Murphy O'Brein's empirical formulation as an effort to mitigate earthquake disasters. This study aims to determine PGA as the level of earthquake activity and intensity as a measure of the damage caused by earthquakes and to analyze their distribution maps. The data used is earthquake data for the period 1936-2022 with a magnitude ≥ 5 Mw and a depth of ≤ 70 km sourced from the catalog of the National Earthquakes Information Center U.S Geological Survey (NEIC/USGS). The results of data processing produce PGA values in West Sumatra ranging from 0.4083 – 782.9839 gal with an intensity (MMI) ranging from I – IX MMI. Map of distribution of PGA values and the highest intensity is in West Pasaman Regency and the lowest value is in Mentawai Islands Regency. The West Pasaman Regency area and its surroundings should meet the requirements for earthquake-resistant buildings, because they have a fairly high PGA value.
THE VARIATIONS OF CLINKER SUPERPARAMAGNETIC VALUE FROM PT. SEMEN PADANG BY USING A BARTINGTON MAGNETIC SUSCEPTIBILITY METER SENSOR TYPE B rina, rina novita; Rifai, Hamdi; Dwiridal, Letmi; Mufit, Fatni
JRFES (Jurnal Riset Fisika Edukasi dan Sains) Vol 11, No 1 (2024): Jurnal Riset Fisika Edukasi dan Sains
Publisher : Universitas PGRI Sumatera Barat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22202/jrfes.2024.v11i1.7986

Abstract

Clinker is a significant material in the cement manufacturing process. Before clinker formation, the raw material is burned in a Rotary Kiln with a temperature of up to 1450℃. After that, it is cooled in a Greet Cooler to a temperature of 100℃ and produces clinker. During the clinker manufacturing process, always being test on samples, but there has been no test based on magnetic susceptibility. The purpose of this research is to know the variation of the superparamagnetic clinker value based on the magnetic susceptibility value. The method used is the rock magnetism method using a Bartington Magnetic Susceptibility Meter MS2B Type. A sampling of clinker is taken hourly every day from PT. Padang Cement. From the value of magnetic susceptibility based on low-field magnetic susceptibility , it was obtained that the values varied from 3.2 × 10-8m3/kg to 22.6 ×10-8m3/kg. The frequency of dependents is also diverse, ranging from 0.0% to 7.4%. Based on the  obtained, the type of grain produced also varies. 136 samples of clinker containing less than 10% superparamagnetic grains, and 32 samples belonging to Medium  have a percentage of 2%-10% where the sample comprises superparamagnetic grains. Between 10% and 75% is a mixture of fine and coarse superparamagnetic grains.
SEISMIC RATE CHANGES ANALYSIS BASED ON THE SPASIAL DISTRIBUTION SEISMOTECTONICS IN THE SOUTHERN SUMATRA REGION Florentina Simalango, Nora; Syafriani, Syafriani; Dwiridal, Letmi; Zulhendra, Zulhendra
JOURNAL ONLINE OF PHYSICS Vol. 10 No. 1 (2024): JOP (Journal Online of Physics) Vol 10 No 1
Publisher : Prodi Fisika FST UNJA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/jop.v10i1.38137

Abstract

The southern Sumatra region experiences high seismic activity, often resulting in large earthquakes that cause significant losses. Before such earthquakes, a phenomenon known as seismic quiescence a decrease in seismic activity commonly occurs. This phenomenon can be analyzed through changes in seismic rates using the spatial distribution of Z-values. This study investigates the occurrence of seismic quiescence before major earthquakes and examines changes in seismic rates in southern Sumatra. Used secondary earthquake data from the United States Geological Survey (USGS) for 1973–2023 were analyzed, focusing on the region between 2.050°S–5.885°S and 101.030°E–106.611°E. The study centered on three significant earthquakes: the 2000 (7.9 Mw), 2001 (7.4 Mw), and 2007 (8.4 Mw) events.  Seismic rate changes were analyzed using the Z-value method, dividing the region into grids to calculate and spatially distribute Z-values. Results showed seismic quiescence before the 2000 (±16 years), 2001 (±13 years), and 2007 (±17 years) earthquakes in Bengkulu. Additionally, similar phenomena were observed in Bengkulu and Lampung before 2023, suggesting the potential for future significant earthquakes in the region. These findings highlight seismic quiescence as a precursor to major seismic events.
Analysis Of Seismic Quiescence Precursors Before The M7.4 Earthquake Of 28 September 2018 In Central Sulawesi Based On Seismotectonic Spatial Distribution And Earthquake Fracture Lengths zu, Zurahma; Syafriani; Dwiridal, Letmi; Zulhendra, Zulhendra
Jurnal Pendidikan, Sains, Geologi, dan Geofisika (GeoScienceEd Journal) Vol. 6 No. 1 (2025): Februari
Publisher : Mataram University

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The Central Sulawesi earthquake with coordinates 2°30‘S -1°50’ N and 119°0'-124°20 E magnitude 7.4 in Palu, Donggala Regency on 28 September 2018. This earthquake was a significant and destructive earthquake in Central Sulawesi. A significant earthquake is preceded by a seismic quiescence. The aim of the study was to determine when the seismic quiescence occurred and seismic activity after the earthquake alongside fracture length. The method of analysis of seismic quiescence and fracture length is z-value and Wells and Coppersmith equation. Data processed with MATLAB and Zmap were 1478 events from 1983-2023. The study area is divided into several grids with sizes of 0.1°* 0.1°. The number of earthquakes included (N = 800, 700, 600, 500, 400, 300, and 200). The z-value was calculated for each grid based on the earthquake data organized in one grid and seismic activity after earthquake. The results of the analysis of the z-value calculation in each grid show of seismic quiescence before a significant earthquake. Based on the results of the spatial distribution of z-value in Central Sulawesi, the seismic quiescence preceded the 28 September 2018 earthquake event (M 7.4) by about 21 years beginning in 1990. When cut at 2019.6, there was a decrease in seismic activity again, which indicated that an earthquake would occur, so it was thought to be a trigger factor for future earthquake precursors. While the fracture length of the 7.4 Mw earthquake of 104,232 meters shows a positive correlation between magnitude and fracture length.
Analysis of Seismicity and Return Period of Earthquakes in South Pesisir Regency West Sumatra Province Using the Likelihood Method Husna, Azmi Asmaul; Syafriani; Hamdi; Letmi Dwiridal
Jurnal Pendidikan, Sains, Geologi, dan Geofisika (GeoScienceEd Journal) Vol. 6 No. 1 (2025): Februari
Publisher : Mataram University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/goescienceed.v6i1.589

Abstract

The South Pesisir area was one of the areas that was rocked by an earthquake on September 30, 2009. The earthquake that occurred caused damage and loss of life. Based on these conditions, the South Pesisir Regency area was identified as an earthquake-prone area. Therefore, it is necessary to research seismicity and return period in the regency. This research used the statistical likelihood method to determine the accumulated rock stress, seismcity and return period of eartquakes. The data used is earthquake data for the period 1934-2023 with a magnitude ≥4 SR and a depth of ≤300 km. The results of this research provided an overview of the seismicity and return period in the South Pesisir Regency. Seismicity was determined based on rock stress condition (b-value) and on the level seismic activity (a-value). Based on calculations showed that the a-value and b-value for the 20-year and 90-year intervals ranged between 6.16-10.9 and 0.953-2.17, respectively. Earthquakes return periods at intervals of 20 years and 90 years for the magnitude range 4.0-4.4 produced almost the same return period, namely less than one year. Meanwhile, earthquakes with magnitudes of 4.5-6 had recurrence periods ranging from 1 to 63 years.
Co-Authors - Hamdi AA Sudharmawan, AA Aditio, Rama Ahmad Fajrin Ahmad Fauzi Akmam Akmam Akmam Amali Putra Amirullah, Fajar Fikri Annisa Rahma Jelita Asrizal Delima Putri Denandra, Alza Dhea Fitria Emriska, Vellya Ramadhani Fadhila Ulfa Jhora Fatni Mufit Fauzi Ahmad Muda Festiyed Florentina Simalango, Nora Fuja Novitra Gusnedi Gusnedi Hamdi Hamdi Hamdi Hamdi Hamdi Hamdi Rifai Handayani, Silvia Sri Harman Amir hidayanti, hidayanti Hidayati Hidayati Hidayati Hidayati Hufri Hufri Husna, Azmi Asmaul Ikram, Riziqul Kiroomin Barorotin Muji lara agustia Madinah, Nur Mahrizal Mahrizal Maidani, Delvi Putri Marlina Alimir Mesi, Mesi Mia Cahyanti Murtiani Murtiani Nengsih, Reni Fitria Nofi Yendri Sudiar Putri Dwi Sari Putri, Ulfa Haldiani Putri, Zakiah Putri Rahmat Hidayat Rahmy Novia Ratnawulan . Renol Afrizon Resi Silvianis Resti Sundari rina, rina novita Salsabila, Salsabila Saqilah, Alya Sari, Nurul Fadillah Silvi Yulia Sari Siska Fitri Alwi Sri Ayu Wahyuni Syafriani Syafriani Syafriani Syafriani Syafriani, Syafriani Syafriani, - Wahyu Ramadhan Yana Ramadhani Yendri Sudiar, Nofi Yurnetti Yurnetti Yusrizal Yusrizal Zainul Adha Zikri, Ahmad Raihan zu, Zurahma Zulhendra Zulhendra Zulhendra Zulhendra, Zulhendra