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All Journal EKSAKTA: Journal of Sciences and Data Analysis Jurnal Penelitian Pendidikan IPA (JPPIPA) INDONESIAN JOURNAL OF APPLIED PHYSICS Jurnal Pengabdian Pada Masyarakat Eksakta : Berkala Ilmiah Bidang MIPA Pelita Eksakta Pillar of Physics Education : Jurnal Berkala Ilmiah Pendidikan Fisika Pillar of Physics: Jurnal Berkala Ilmiah Fisika Journal of Climate Change Society Journal of Experimental and Applied Physics

Letmi Dwiridal

Universitas Negeri Padang

Author-ID : 2756622

Agriculture, Biological Sciences & Forestry Humanities Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Social Sciences Other

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Analisis kondisi pasang surut dengan waktu kejadian gempabumi Sumatera Barat (Analysis of tidal conditions with the time of the earthquake in West Sumatera) Elka Fitri Enora; Letmi Dwiridal
PILLAR OF PHYSICS Vol 13, No 1 (2020)
Publisher : Department of Physics – Universitas Negeri Padang UNP

Tides are a phenomenon of movement of the ups and downs of the surface of the sea water at intervals caused by a combination of the gravitational force and the attractive force of celestial bodies, especially by the sun, earth and moon. Earthquake events can occur from earth rock rock fractures by forces (including gravitational forces) that are collected slowly, and earthquakes can also occur if the stress shear causes the force to exceed the strength of the rock, causing deformation. Analysis of tidal conditions with the time of the West Sumatran earthquake in the period 2009-2019. The increase of tides in the period 2009 is on the 2009-09-30 has a depth of 79 km above sea level which is in the Mentawai Islands. Meanwhile, in the year 2010 there are 2010-10-25 has a depth of 10 km above sea level in the Mentawai Islands. In 2011 it was in the year 2011-08-04 had a depth of 41 km on sea level in the Mentawai Islands. While in the period 2016 there are 2016-06-01 has a depth of 69 km above the surface of the sea water in the Siberut estuary. In the period 2018 there are 21/04/2018 has a depth of 35 km are in the Siberut estuary.

Analisis karakteristik periode ulang curah hujan dengan metode Iwai Kadoya di daerah lokal sumatera barat dan regional sumatera (Analysis of the characteristics of the return period of rainfall using the Iwai Kadoya method in the local area of West Sumatra and regional Sumatra) Mia Nova Isnia Gara; Letmi Dwiridal; Sugeng Nugroho
PILLAR OF PHYSICS Vol 12, No 2 (2019)
Publisher : Department of Physics – Universitas Negeri Padang UNP

Sumatera is located in the western part of Indonesia, this result in the Sumatera region has high rainfall, due to the west monsun origaniting from the Indian Ocean a lot through the western part of Indonesia. Sumatera Island are divided into three major parts that have different regional topographies and type pf rainfall, so that characteristics of rainfall in Sumatera are different in each region. High rainfall results in natural disaster, to reduce the impact of disaster mitigation, the rainfall return periodis also used to predict the time needed to resume maximum rainfall. In this study, calculate the rainfall return period from 8 stations. From the calculation results it is known that the re-period of highest rainfall is at the Meteorogical Station of Minang Kabau Airport in the period 1999-2018 with a return period of 30 days- 300 years with the rainfall frequency pf 186-524 mm/day, with equatorial rain type.

Distribution Pattern of Magnetic Susceptibility Value of Iron Sand on the Surface of Pasia Jambak Beach Pasia Nan Tigo Padang Riza Rahmayuni; Hamdi Rifai; Letmi Dwiridal; Ardilla Nofri Yuwanda; Dwi Anisa Visgus; Anisa Rahmi
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 22 No. 4 (2021): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Iron sand is a natural resource in Indonesia that can be utilized based on magnetic mineral content (Fe203, Fe3O4, FeTiO3), to be processed into materials of high economic value. Iron sand magnetic mineral distribution was analyzed to see potential in Pasia Jambak Beach, Pasia Nan Tigo, Padang, where the iron sand in this area has not been fully utilized by the community and government. The potential of iron sand can be seen usiing Magnetic Method with a magnetic chaaracteristic test in the form of the susceptibility value of iron sand. Magnetic susceptibility value iron sand on the surface of Pasia Pantai Jambak varies betwen 485,2 × 10-8 m3/kg up to 13077 × 10-8 with an average 3.306, 37 × 10-8 m3/kg.. The results of the contour map show that high-value magnetic susceptibility values are scattered near the estuary, namely Muaro Anai and Muaro Baru, this is because magnetic minerals (Fe203, Fe3O4, FeTiO3) which have high density are more likely to settle near the estuary, then the rest spreads to the coast.

Optimizing the Use of Physics KITs that are integrated with the Scientific Context and Its Impact for Physics Teachers Renol Afrizon; Hidayati Hidayati; Letmi Dwiridal; Najmil Khaira
Jurnal Penelitian Pendidikan IPA Vol. 7 No. 4 (2021): October
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v7i4.1042

The background of this research is the lack of competence of physics teachers in using physics KIT. This research was conducted with the hope that there will be an increase in the competence of senior high school physics teachers in West Pasaman in using the physics KIT. This research was conducted with a quasi-experimental design and one group pretest-posttest. This study has a population of all physics teachers who join physics teachers group in West Pasaman Regency. The sample was taken by using simple random sampling technique, selecting 22 teachers as representatives of the physics teachers group in West Pasaman Regency. The results showed an increase in teachers' competence in using the physics KIT after mentoring the use of the physics KIT. The increase in teacher competence can be described through the value of again, the N-gain value obtained is 0.33 (moderate). This means that the teacher's competence in using the physics KIT can increase after mentoring the use of the physics KIT.

Characterization of Magnetic Minerals of Iron Sand Pasia Nan Tigo Padang Beach Using X-Ray Diffraction (XRD) Ardilla Nofri Yuwanda; Riza Rahmayuni; Dwi Anisa Visgun; Anisa Rahmi; Hamdi Rifai; Letmi Dwiridal
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 12, No 1 (2022): IJAP Volume 12 ISSUE 01 YEAR 2022
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v12i1.51531

The mineral extraction of iron sand from Pasia Nan Tigo Beach has been carried out. Iron sands in this area are widely spread and have decent potential but have not been used optimally. The iron sand of Pasia Nan Tigo Beach contains minerals that are indicated by the variation in susceptibility values of type 265.8×10-8m3/kg to 12,445.53×10-8m3/kg. Therefore, it is necessary to separate minerals from iron sand so that the minerals contained in them are known so that they are suitable for usability. The iron sand obtained is extracted using two magnets, namely a strong magnet and a weak magnet. The extraction results from iron sand still contain impurities to remove them, the sand is purified and then the sand extraction results are characterized using the XRD method. Content The type and structure of the mineral species found in the samples extracted from iron sand using strong magnets are Magnetite (Fe3O4) with Cubic structure, Hematite (α-Fe2O3) with Hexagonal structure, and Ilmenite (FeTiO3) with Hexagonal structure. While the use of weak magnets is Magnetite (Fe3O4) with Cubic structure, Hematite (α-Fe2O3) with Rhombohedral structure, and Ilmenite (FeTiO3) with Rhombohedral structure. Meanwhile, the non-magnetic mineral namely Quartz (SiO2), works as an impurity. The average crystal size using a strong magnet for PNT-B01 0-5 cm is 100.85 nm and a weak magnet is 49.36 nm, sample A06 30-35 cm uses a strong magnet of 88.25 nm and a weak magnet of 46, 80 nm, meanwhile sample B10 0-5 cm with a strong magnet of 109.22 nm and a weak magnet of 45.60 nm.

Peningkatan Kompetensi Guru-Guru IPA SMP/MTsN Lubuk Sikaping melalui Pelatihan Pengembangan Bahan Ajar Berbasis Kontekstual Hufri Hufri; Letmi Dwiridal; Silvi Yulia Sari
Jurnal Pengabdian Pada Masyarakat Vol 6 No 1 (2021)
Publisher : Universitas Mathla'ul Anwar Banten

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30653/002.202161.502

INCREASING THE COMPETENCE OF SCIENCE TEACHERS OF SMP/MTSN LUBUK SIKAPING THROUGH CONTEXTUAL-BASED LEARNING MATERIALS DEVELOPMENT TRAINING. This activity aims to improve the competence of science teachers SMP/MTsN Lubuk Sikaping through training development of contextual based teaching materials. To achieve the objectives and targets set, the method used consists of observation, orientation and discussion, preparation, implementation, monitoring and evaluation. The instruments used are tests of understanding of the material and questionnaire responses of trainees. Data analysis techniques used are paired t test and percentage analysis Based on data analysis, obtained the average value of pretest is 46.2676 and at postest 63.0672. Furthermore, paired t test, obtained results of significance 0.000 <0.05. This indicates that there is an increase in the competence of IPA teachers of SMP/MTsN Lubuk Sikaping through training of contextual based teaching materials. Based on the questionnaire given at the end of the training activities, that the activity is very useful and related to the subjects which is taught in schools.

TEACHING MATERIAL BASED ON REVISED BLOOM’S TAXONOMY ON THE CONCEPT OF A MAGNETIC FIELD IN SENIOR HIGH SCHOOL Miftahul Jannah; Amali Putra; - Hufri; Letmi Dwiridal
PILLAR OF PHYSICS EDUCATION Vol 14, No 4 (2021)
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/12123171074

Bahan ajar fisika yang digunakan dalam pembelajaran fisika harus mampu mengembangkan pengetahuan dan meningkatkan kemampuan proses kognitif siswa. Kenyataan di lapangan menunjukkan bahwa bahan ajar yang belum memenuhi harapan tersebut. Penelitian ini bertujuan untuk mengembangkan ajar taksonomi Bloom revisi konsep medan magnet pada pembelajaran fisika SMA dan mengetahui validitas dan pengembangan bahan ajar taksonomi Bloom revisi konsep medan magnet kelas XII SMA. Jenis penelitian yang digunakan adalah Research And Development (RnD) dengan mengambil model ADDIE (Analysis, Design, Development, Implementation, and Evaluation) yang diturunkan ke tahap pengembangan. Subyek penelitian adalah 3 orang dosen fisika UNP dan 3 orang guru fisika dari SMAN 1 Kampar Timur,SMAN 2 Kampar dan SMAN 1 Kampar Utara, dengan objek penelitian bahan ajar berbasis taksonomi Bloom. Revisi perangkat pembelajaran yang terdiri dari RPP, bahan ajar, dan instrumen. Evaluasi bahan magnet medan. Berdasarkan analisis data yang telah dilakukan, validitas bahan ajar berdasarkan taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA menurut tim ahli yang memperoleh hasil analisis dengan rata-rata 82,4% dan menurut tim praktik dengan rata-rata 91 , 73%. Secara keseluruhan diperoleh 87,06% dalam kategori yang valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA. dengan objek penelitian bahan ajar berbasis taksonomi Bloom.Revisi perangkat pembelajaran yang terdiri dari RPP, bahan ajar, dan instrumen. Evaluasi bahan magnet medan. Berdasarkan hasil analisis data yang telah dilakukan, validitas bahan ajar berdasarkan taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA menurut tim ahli yang memperoleh hasil analisis dengan rata-rata 82,4 % dan menurut tim praktik dengan rata-rata 91, 73%.Secara keseluruhan diperoleh 87,06% dalam kategori yang valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA. dengan objek penelitian bahan ajar berbasis taksonomi Bloom. Revisi perangkat pembelajaran yang terdiri dari RPP, bahan ajar, dan instrumen. Evaluasi bahan magnet medan. Berdasarkan hasil analisis data yang telah dilakukan, validitas bahan ajar berdasarkan taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA menurut tim ahli yang memperoleh hasil analisis dengan rata-rata 82,4 % dan menurut tim praktik dengan rata-rata 91, 73%.Secara keseluruhan diperoleh persentase 87,06% dalam kategori sangat valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA. Revisi perangkat pembelajaran yang terdiri dari RPP, bahan ajar, dan instrumen. Evaluasi bahan medan magnet. Berdasarkan hasil analisis data yang telah dilakukan, validitas bahan ajar berdasarkan taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA menurut tim ahli diperoleh hasil analisis dengan rata-rata 82,4 % dan menurut tim praktisi dengan rata-rata 91,73%. Secara keseluruhan diperoleh persentase 87,06% dalam kategori sangat valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA. Revisi perangkat pembelajaran yang terdiri dari RPP, bahan ajar, dan instrumen. Evaluasi bahan medan magnet. Berdasarkan hasil analisis data yang telah dilakukan, validitas bahan ajar berdasarkan taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA menurut tim ahli diperoleh hasil analisis dengan rata-rata 82,4 % dan menurut tim praktisi dengan rata-rata 91,73%. Secara keseluruhan diperoleh persentase 87,06% dalam kategori sangat valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA. validitas bahan ajar taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA, menurut tim ahli, hasil analisis dengan rata-rata 82,4% dan menurut tim praktisi dengan rata-rata 91, 73%. Secara keseluruhan diperoleh 87,06% dalam kategori yang valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA. validitas bahan ajar taksonomi Bloom Revisi pada konsep medan magnet pada pembelajaran fisika di kelas XII SMA, menurut tim ahli, hasil analisis dengan rata-rata 82,4% dan menurut tim praktik dengan rata-rata 91, 73%. Secara keseluruhan diperoleh 87,06% dalam kategori yang valid secara teoritis dan dapat dilanjutkan dengan uji coba lapangan untuk mengetahui kepraktisan dan keefektifannya dalam pembelajaran fisika di SMA.

Analysis of b-Value and Peak Ground Acceleration (PGA) in West Sumatra Province using Maximum Likelihood Method and Empirical Formula (Earthquake data Period 2007-2020) Fandu Alfadilah; - Syafriani; - Hamdi; Letmi Dwiridal; Fajri Syukur Rahmatullah
PILLAR OF PHYSICS Vol 15, No 1 (2022)
Publisher : Department of Physics – Universitas Negeri Padang UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/12553171074

West Sumatra Province has four active fault segments, namely part of the Sumatran fault zone which causes frequent earthquakes. Therefore, it is necessary to research b-value analysis and PGA in the province of West Sumatra by using the maximum likelihood method and empirical formula for earthquake disaster mitigation efforts. This study aims to determine the b-value associated with rock stress and PGA as the level of earthquake activity and analyze the distribution map. The data used is earthquake data for the period 2007-2020 with a magnitude ≥ 5 SR and a depth of ≤ 100 km. The results of data processing produce a map of the distribution of b-value and PGA in the province of West Sumatra. The b-value in each region ranged from 0.8421-1.4477. Based on the b-value distribution map, the area that has the smallest b-value is in region 6, while the largest value is in region 2. A low b-value correlates with high rock stress conditions. This value illustrates that area 6 has a high chance of a major earthquake occurring. Furthermore, the calculation of the PGA value refers to the general form of Lin and Wu's empirical equation to obtain a new empirical formula model. The value of the coefficient a=−1.20543, b=−0.839093, and c=6.88858. The PGA value of West Sumatra province ranges from 10.87-376.98 gal. The city/regency with the largest PGA value is in the Mentawai Islands Regency, which ranges from 84.11-328.17 gal and the lowest value is in Dharmasraya Regency, which is between 10.87-35.28 gal.

Identification of Elemental Content and Rock Types in West Lampung Regency Nadya Fitra Kurnia; Hamdi Rifai; Syafriani Syafriani; Letmi Dwiridal; Fatni Mufit
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 3, ISSUE 2, August 2022
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol3.iss2.art1

Rock is a constituent of the earth's crust from a collection of minerals that harden due to natural processes. Rocks formed from volcanic eruption materials in each place have different characteristics in distribution patterns, types of minerals and the content of elements contained therein. These rocks contain elements that form magnetic minerals. However, in rocks in West Lampung Regency the elemental content in the rocks has not been identified. This study aims to determine the composition of rock-forming elements and rock types found in West Lampung Regency. The elemental content in rocks can be identified using X- Ray Fluorescence (XRF) and determine rock types using SiO2and K2O diagrams. The results of the analysis using XRF show that Si (Silica) is the most dominant element found in 4 rocks in Lampung Regency. West. In addition, the elements found in rocks in West Lampung are Al, Si, K, Ca, Fe, P, Cl, Ti, Mn, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Ag, In, Eu, and Pb , from the content of these elements there are elements that form magnetic minerals, namely Fe and Ti , with rock types of Foidite and Decite.

Effect of Air Temperature, Air Humidity, and Air Pressure on Rainfall Based on Measurement Result in Kototabang Syahrul Gunawan; - Asrizal; - Hufri; Letmi Dwiridal; Ikhsan Buyung Arifin; Fahmi Rahmatia
PILLAR OF PHYSICS Vol 15, No 2 (2022)
Publisher : Department of Physics – Universitas Negeri Padang UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/13007171074

Weather has a close relationship with community activities in Kototabang. Weather information can be used so that the risk of crop failure and disaster hazards can be minimized. Research to investigate the relationship of weather parameters was carried out using descriptive research with the multiple linear regression method. The variables in this study were divided into independent variables of air temperature, air pressure, and humidity, and the available variable was rainfall. The research method used is a multiple linear regression method with secondary data measurement of AWS and AAWS in Kototabang. The multiple linear regression method aims to predict values based on independent variables. The characteristic of this method is the presupposition variable used by more than one variable. The data processing technique applied was a multiple regression linear with three predictors (temperature, humidity, and air pressure) with the characteristics of three predictors. The purpose of the translation technique, in general, is to describe the effect of the predicted parameters on rainfall. From the output obtained, it is explained that there is a positive contribution from the predictive variable to rainfall. The correlation that occurs from the output is also very strong, reaching an output value of 99.1%. Simultaneously and partially explained that there is a large enough change in the presumed parameters (air pressure, temperature, and humidity) to rainfall. This proves that there is a very rapid change between pressure, humidity, and air temperature to rainfall in Kototabang in 2020.

Co-Authors - Asrizal - Hamdi Ahmad Fauzi Akmam Akmam Angeline Chika Rorensia Anisa Rahmi Anisa Rahmi Ardilla Nofri Yuwanda Ardilla Nofri Yuwanda Cindy Magriza Putri Dessri Mai Syarif Dian Laila Fitri Dwi Anisa Visgun Dwi Anisa Visgus Eka Fitri Eko Muda Setiawan Elka Fitri Enora Fadhil Ramadhani Fahmi Rahmatia Fajri Syukur Rahmatullah Fandu Alfadilah Fanny Rahmatina Rahim Fatni Mufit Festiyed Gusmita Cahnia Putri Hamdi Hamdi Rifai Harman Amir Hidayati Hidayati Hilmi Rizki Anjani Hufri Hufri Ika Sri Fahmi Ikhsan Buyung Arifin Juliana Dekriani Lingga Ayunda Pradipta Mia Nova Isnia Gara Miftahul Jannah nabila aulia rahma Nadya Fitra Kurnia Najmil Khaira Nofi Yendri Sudiar Putra, Amali Putri Nurhaliza Ramli Ramli Randy Ratnawulan . Renol Afrizon Rifqa Hayati Riza Rahmayuni Riza Rahmayuni Sadinda Tsania Suhada Silvi Yulia Sari Silvia Irani Sugeng Nugroho Syafriani Syafriani Syafriani Syahrul Gunawan Trio Junira Fernando Yenni Darvina Yunita Syafitri Yurnetti Yurnetti Zulhendra Zulhendra

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