cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Leni Rumiyanti
Contact Email
lenirumiyanti@fmipa.unila.ac.id
Phone
-
Journal Mail Official
lenirumiyanti@fmipa.unila.ac.id
Editorial Address
-
Location
Kota bandar lampung,
Lampung
INDONESIA
Jurnal Teori dan Aplikasi Fisika
Published by Universitas Lampung
ISSN : 2303016X     EISSN : 25491156     DOI : -
Core Subject : Science,
Materials Science & Nanotechnology Physics
Jurnal ini diterbitkan oleh Jurusan Fisika Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Lampung sebagai sarana untuk mempublikasikan hasil penelitian, artikel review dari peneliti-peneliti di bidang fisika teori dan aplikasinya. Jurnal ini terbit dua kali setahun (Januari dan Juli).
Arjuna Subject : -
Articles 332 Documents
 26   27   28   29   30 
Pengujian Prototipe Instrumen Pengukuran Gradien Termal di Lapangan Panas Bumi Padang Cermin Pesawaran Karyanto Karyanto; I Gede Boy Darmawan
Jurnal Teori dan Aplikasi Fisika Vol 9, No 2 (2021): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v9i2.2775

Abstract

Hasil perancangan prototipe instrumen pengukuran gradien termal yang telah dilakukan sebelumnya membutuhkan pengujian lapangan. Pengujian ini bertujuan untuk melihat kemampuan instrumen prototipe dalam uji pengukuran langsung di lapangan panas bumi. Metode yang digunakan dalam pengujian adalah dengan membandingkan hasil pengukuran suhu pada instrumen prototipe dengan hasil pengukuran suhu menggunakan instrumen MAE A5000T penelitian sebelumnya di Padang Cermin. Penghitungan gradien termal dilakukan secara otomatis oleh sistem dalam prototipe menggunakan teknik kuadrat terkecil (Least Squares Method). Hasil pengukuran menunjukkan adanya keselarasan suhu khususnya pada area manifestasi. Peta sebaran suhu mengindikasikan pola klasterisasi yang menunjukkan hubungan aliran fluida panas, khususnya pada arah barat-timur. Adanya konektivitas fluida panas ini diinterpretasikan sebagai struktur geologi atau zona permeable pada area manifestasi. Hasil pengukuran gradien termal juga menunjukkan pola gradien tinggi di area manifestasi panas bumi. Selain itu, sebaran nilai suhu rendah pada ketiga layer juga mengindikasikan sumber aliran fluida air permukaan yang selaras dengan arah puncak gunung. Hal ini memperkuat indikasi bahwa sumber recharge atau resapan air meteorik didominasi oleh puncak Gunung Ratai. Temuan ini mengindikasikan bahwa prototipe instrumen pengukuran gradien termal ini mampu digunakan di lapangan panas bumi.
Pengaruh Ethanolamina Terhadap Pembentukan Fasa, Ukuran Partikel, dan Luas Permukaan Spesifik Nanotitania Menggunakan Metode Sol Gel Renita Maharani Fauzi; Posman Manurung; Yanti Yulianti
Jurnal Teori dan Aplikasi Fisika Vol 9, No 2 (2021): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v9i2.2716

Abstract

Nanotitania has been prepared by sol gel method using ethanolamine as surfactant. This research was conducted to determine the effect of ethanolamine on the phase formation, particle size and surface area of TiO2. In this study Ti-butoxide was used as a precursor and ethanol as a solvent, and then HCl. The amount of ethanolamine was varied to 0; 0.5; 1; 1.5; and 2 ml. The samples were calcined at a temperature of 500ºC for 4 hours. TiO2 was characterized using X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Surface Area Analyzer (SAA) with BET method. The results of XRD characterization showed that in samples A-0.0 and A-0.5 an anatase phase was formed, whereas in the sample A-1,0 and A-1,5 an anatase, brookite, and rutile phases were formed with a weight percentage of 57,65 ± 1,6% wt; 27,06 ± 1,8% wt, and 15,29 ± 0,4% wt. Meanwhile, for sample A-1,5  it is 69,96 ± 1.6% wt, 24,52 ± 1,5% wt, and 5,52 ± 0,3% wt. Sample A-2.0 only produced anatase and brookite phases with weight percentages of 78,53 ± 1.5% wt and 21,47 ± 1.5% wt. The results of TEM characterization using ImageJ software show that the TiO2 particle size in sample A-1,0 was 15,8 ± 1,0 nm. The results of the analysis surface area of sample A-1, produced the largest specific surface area, that is 172 m2/g, the smallest specific surface area was produced in sample A-1,5  that is 72,07 m2/g.
Studi Pendahuluan Pembentukan Struktur Komposit Perak Silika (Ag/SiO2) Berbasis Sekam Padi Janariah Janariah; Jessy Oktayulia Sari; Simon Sembiring; Junaidi Junaidi
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2889

Abstract

Penelitian mengenai sintesis komposit perak silika (Ag/SiO2) telah dilakukan melalui metode sol-gel dengan menggunakan variasi konsentrasi koloid perak nitrat (AgNO3) yaitu 0,3; 0,5; dan 0,7 M ke dalam sol silika sekam padi dengan perlakuan termal suhu 110 oC dan suhu  sintering 850 oC. Tujuan dari penelitian ini yaitu sebagai studi pendahuluan pembentukan struktur komposit Ag/SiO2 melalui karakterisasi X-ray diffraction (XRD). Analisis XRD menunjukkan bahwa jumlah konsentrasi AgNO3 mempengaruhi kenaikan intensitas pada 2θ. Pada konsentrasi 0,3 M struktur silika (SiO2) yang dihasilkan masih dalam bentuk amorf dan intensitas perak (Ag) tidak terlalu besar, sehingga dengan penambahan konsentrasi 0,5 dan 0,7 M intensitas struktur puncak silika sudah terlihat dan bertambahnya intensitas puncak dari struktur perak.
The Effect Of Exposure Index Variations On Subjective Quality Assessment On Lumbosacral Examination Putri Rahmawanti; Muhammad Irsal; Gando Sari
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2922

Abstract

Exposure index (EI) is an indicator of dose used to determine overexposed, optimal and underexposed images so that this study discusses the effect of EI variations on subjective image quality assessment on lumbosacral examination. This research uses descriptive quantitative method by filling out questionnaires and calculating the radiation output dose. Then to draw conclusions, perform a visual grading analysis (VGA) statistical test using the one-way ANOVA test. The results obtained by varying the EI for AP projections of 2.99 (overexposed), 2.79 (optimal), and 2.33 (underexposed) then for Lateral projections of 2.91 (overexposed), 2.76 (optimal), and 2.46 (underexposed). Furthermore, the dose calculation using the radiation output equation produces 3.158 mGy (overexposed), 0.78 mGy (optimal) and 0.57 mGy (underexposed) for the AP projection while for the lateral projection it produces a radiation dose of 3.61 mGy (overexposed), 1.52 mGy (optimal). , and 0.78 mGy (underexposed). Then to get a conclusion, VGA test was carried out using ANOVA testing, the data generated after performing ANOVA tests on AP and lateral projections showed results of 0.87 and 0.612. Based on the results of the ANOVA that has been carried out, the conclusion is that all respondents have the same assessment of the quality of the lumbosacral image that the image with the overexposed EI indicator is a better image than the image with the optimal and underexposed EI indicator.
Fabrikasi Nanofiber PVA/Fe3O4 dengan Metode Elektrospinning Nuril Fathurin; Diah Hari Kusumawati
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2911

Abstract

PVA/Fe3O nanofibers are composite materials contain magnetic materials in nanometer-sized fibers that have biocompatible, non-toxic, and high chemical stability properties. It makes Fe3O nanoparticles suitable for application in the biomedical field as a Drug Delivery System or targeted drug delivery system. Fe3O will be composited with Polyvinyl Alcohol (PVA) and formed into nanofibers. The purpose of this study was to analize the effect of variations in volume % concentration of F Fe3O used on PVA/Fe3O nanofibers. Fe3O was dissolved in dionized water using ultrasonication. The suspension of  Fe3O solution was mixed with 10% PVA solution to form PVA/Fe3O solution with Fe3O variations of 5%, 10%, 15%, and 20%. Electrospinning process was carried out on PVA/Fe3O solution with a voltage of 20 kV, flow rate of 5 ml/hour, distance of jet to collector is 15 cm. The results of SEM characterization can be concluded that the one that has the best morphology in this study is PVA/Fe3O nanofiber with a concentration of 10% because it generates uniform nanofibers with the smallest diameter at this concentration, the fibers do not attach to one other, and there are no beads.
Studi Pendahuluan Pembentukan Gugus Fungsi dari Komposit Perak Silika (Ag/SiO2) Berbasis Sekam Padi Rifa Dian Eka Farah; Nur Fattiah Amanda; Simon Sembiring; Junaidi Junaidi
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2891

Abstract

Research has been carried out with the aim of studying the formation of functional groups of a composite of silver silica (Ag/SiO2) based on rice husk silica and silver nitrate (AgNO3) as a precursor using the sol-gel method. Variations in the concentration of AgNO3 used were 0,3M; 0,5M; and 0,7 M with a thermal temperature of 850 °C. The results of Fourier transform infrared spectroscopy (FTIR) showed the formation of Si-O-Si, Si-O, and O-N-O functional groups which were the result of AgNO3 residue indicating the presence of Ag.
INVESTIGATION OF NATURAL EXTRACTS AS GREEN CORROSION INHIBITORS IN STEEL USING DENSITY FUNCTIONAL THEORY Muhamad Akrom
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2927

Abstract

One of the materials with low corrosion resistance is steel when it interacts with a corrosive environment. The use of green inhibitors is able to provide good corrosion inhibition performance with high inhibition efficiency on steel. Green inhibitors which in their compound structure contain heteroatom groups (such as O, N, S, P) and aromatic rings are efficiently used as corrosion inhibitors in steel. This paper provides an important comparative overview for the development of green inhibitors of natural extracts in steel. The study of DFT at the atomic level based on molecular orbitals, chemical quantum parameters, and adsorption characteristics showed results that were in accordance with experimental results. The distribution of electron density through the Frontier Molecular Orbitals (FMO) plot illustrates the prediction of active sites through the distribution of the HOMO-LUMO region of inhibitor molecules that interact with the steel surface. To get the correlation between the electronic properties of the inhibitor molecule and the corrosion inhibition potential, calculate the quantum chemical parameters such as ionization potential (I), electron affinity (A), global hardness (η), absolute electronegativity (χ), global softness (σ) , the transferred electron fraction (ΔN), global electrophilicity (ɷ) and electron return donation (ΔEback-donation) indicate the reactivity of inhibitor molecules which have excellent potential to interact and bind strongly to metal surfaces, thus potentially producing high inhibitory efficiency. The mechanism of corrosion inhibition can be through chemical adsorption and/or physical adsorption by forming a complex compound between the inhibitor molecule and the steel surface to protect it from the corrosive environment. The development of future studies should be able to display the mechanism of interaction and inhibition of inhibitor molecules in more detail and systematically at the atomic level on several metal surfaces such as Fe, Al, Cu, and others.
Analisis Uji Peluncuran Roket Air Berbasis Carbon Fiber Menggunakan Sistem Telemetri Qonitatul Hidayah; Umi Salamah; Margi Sasono
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2912

Abstract

Rocket technology with water propellant is becoming more popular and as an alternative to be applied to education and recreation, such as industry and the military. The use of water rockets as an easy, safe, and inexpensive means of measuring physical parameters at heights above the earth's surface is being intensively carried out. One alternative solution is aerodynamic water rocket technology equipped with a telemetry system. The rocket used for the test launch is made from untested carbon fiber. Flight test settings by filling 1/3 of the tube volume with water and a pressure of 200 psi. The results of the water rocket launch show a maximum height of 265 feet or 80.77 m. Changes in acceleration on the x-axis, y-axis, and z-axis indicate the normal motion of the flying rocket. Analysis of stability and control of the rocket is seen in the measurement of the tilt angle of roll, pitch, and yaw. When the rocket moves or tilts, the angle measured corresponds to the tilt. In the roll condition, the rocket moving from launch to landing shows the rocket's rotational motion at an angle of approximately 20o. The potential of water rockets that can still be developed, needs to be increased the reliability of water rockets both in terms of utilization and research.
KARAKTERISTIK STRUKTUR DAN TERMAL KOMPOSIT ASPAL KARBOSIL SILIKA SEKAM PADI Devi Yulianti; Simon Sembiring; Junaidi Junaidi
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2898

Abstract

Telah dilakukan sintesis dan karakterisasi aspal yang dimodifikasi dengan karbosil dan silika. Penelitian ini dilakukan untuk mengetahui mikrosuktur dan struktur komposit aspal karbosil silika dengan perbandingan komposisi berat yaitu 50:50:0; 42,5:42,5:15; 40:40:20; 37,5:37,5:25; 35:35:30; 32,5:32,5:35. Silika diperoleh dengan menggunakan metode alkalis dan karbosil diperoleh dengan metode pirolisis. Hasil analisis XRD diperoleh fasa yang terbentuk dari setiap variasi komposisi adalah fasa amorf. Analisis DTA/TGA menunjukkan terjadinya perubahan energi akibat penambahan panas dengan ditandai adanya penyusutan massa pada sampel. Variasi komposisi pada sampel menunjukkan terjadinya penurunan nilai pada kuat tekan, porositas dan perubahan ketebalan.
Local Adaptive Thresholding Menggunakan Metode Sauvola sebagai Tahapan Pra Pengolahan pada Data Citra Isyarat ECG Mohammad Rofi'i; Diah Rahayu Ningtias
Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v10i1.2904

Abstract

Kondisi seseorang dapat diketahui dari aktivitas kelistrikan jantung yang telah direkam dan dicetak dalam bentuk electrocardiogram (ECG). Data ECG dapat digunakan dalam penelitian sebagai modalitas bahan untuk analisis dan diagnosis kondisi jantung. Data tersebut dapat berupa isyarat satu dimensi maupun isyarat dua dimensi dalam bentuk citra atau gambar. Pengolahan isyarat ECG yang diambil dari data cetak fisik di scan untuk mendapatkan data digital sehingga dapat diolah dengan menggunakan komputer. Penelitian ini bertujuan untuk mempersiapkan data citra ECG dalam tahap pra pengolahan yang siap diolah pada tahap selanjutnya, baik untuk keperluan analisis maupun diagnosis melalui data citra ECG. Sehingga diharapkan dapat memudahkan dan menampilkan hasil yang optimal untuk berbagai penelitian dengan modalitas data citra ECG.Algoritma yang diterapkan menggunakan metode pengambangan lokal dari sauvola tecnique. Dengan menggunakan nilai R sebesar 128 dan nilai k=0,34 telah menghasilkan citra isyarat ECG tersegmentasi yang bersih tanpa grid. Dengan melihat nilai MSE dan PSNR dari masing-masing metode menunjukkan algoritma sauvola mendapatkan hasil yang lebih baik dari pengambagan global.

Page 28 of 34 | Total Record : 332

 26   27   28   29   30 

Filter by Year

2013 2024


Reset
Filter By Issues
All Issue Vol 12, No 1 (2024): Jurnal Teori dan Aplikasi Fisika Vol 11, No 2 (2023): Jurnal Teori dan Aplikasi Fisika Vol 11, No 1 (2023): Jurnal Teori dan Aplikasi Fisika Vol 10, No 1 (2022): Jurnal Teori dan Aplikasi Fisika Vol 9, No 2 (2021): Jurnal Teori dan Aplikasi Fisika Vol 9, No 1 (2021): Jurnal Teori dan Aplikasi Fisika Vol 8, No 2 (2020): Jurnal Teori dan Aplikasi Fisika Vol 8, No 1 (2020): Jurnal Teori dan Aplikasi Fisika Vol 7, No 2 (2019): Jurnal Teori dan Aplikasi Fisika Vol 7, No 1 (2019): Jurnal Teori dan Aplikasi Fisika Vol 7, No 1 (2019): Jurnal Teori dan Aplikasi Fisika Vol 6, No 2 (2018): Jurnal Teori dan Aplikasi Fisika Vol 6, No 2 (2018): Jurnal Teori dan Aplikasi Fisika Vol 6, No 1 (2018): Jurnal Teori dan Aplikasi Fisika Vol 6, No 1 (2018): Jurnal Teori dan Aplikasi Fisika Vol 5, No 2 (2017): Jurnal Teori dan Aplikasi Fisika Vol 5, No 2 (2017): Jurnal Teori dan Aplikasi Fisika Vol 5, No 1 (2017): Jurnal Teori dan Aplikasi Fisika Vol 5, No 1 (2017): Jurnal Teori dan Aplikasi Fisika Vol 4, No 2 (2016): Jurnal Teori dan Aplikasi Fisika Vol 4, No 2 (2016): Jurnal Teori dan Aplikasi Fisika Vol 4, No 1 (2016): Jurnal Teori dan Aplikasi Fisika Vol 4, No 1 (2016): Jurnal Teori dan Aplikasi Fisika Vol 3, No 2 (2015): Jurnal Teori dan Aplikasi Fisika Vol 3, No 2 (2015): Jurnal Teori dan Aplikasi Fisika Vol 3, No 1 (2015): Jurnal Teori dan Aplikasi Fisika Vol 2, No 2 (2014): Jurnal Teori dan Aplikasi Fisika Vol 2, No 2 (2014): Jurnal Teori dan Aplikasi Fisika Vol 2, No 1 (2014): Jurnal Teori dan Aplikasi Fisika Vol 2, No 1 (2014): Jurnal Teori dan Aplikasi Fisika Vol 1, No 2 (2013): Jurnal Teori dan Aplikasi Fisika Vol 1, No 1 (2013): Jurnal Teori dan Aplikasi Fisika More Issue