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Numerical Analysis of Energy Converter for Wave Energy Power Generation-Pendulum System Aminuddin, Jamrud; Effendi, Mukhtar; Nurhayati, Nurhayati; Widiyani, Agustina; Razi, Pakhrur; Wihantoro, Wihantoro; Aziz, Abdullah Nur; Abdullatif, R Farzand; Sunardi, Sunardi; Bilalodin, Bilalodin; Arifin, A
International Journal of Renewable Energy Development Vol 9, No 2 (2020): July 2020
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.9.2.255-261

Abstract

The wave energy power generation-pendulum system (WEPG-PS) is a four-wheeled instrument designed to convert wave power into electric energy. The first wheel is connected to the pendulum by a double freewheel, the second and third are ordinary wheels, while the fourth is a converter component that is axially connected to the electric generator. This design used the Euler-Lagrange formalism and Runge-Kutta method to examine an ideal dimension and determine the numerical solution of the equation of motion related to the rotation speed of the wheels. The result showed that the WEPG-PS' converter system rotated properly when its mass, length, and moment of inertia are 10 kg, 2.0 m, and 0.25 kgm2, respectively. This is in addition to when the radius of the first, second, third, and fourth wheels are 0.5, 0.4, 0.2, and 0.01 m, with inertia values of 0.005, 0.004, 0.003, and 0.1 kgm2. The converter system has the ability to rotate the fourth wheel, which acts as the handle of an electric generator at an angular frequency of approximately 500 - 600 rad/s. The converter system is optimally rotated when driven by a minimum force of 5 N and maximum friction of 0.05. Therefore, the system is used to generate electricity at an amplitude of 0.3 - 0.61 m, 220 V with 50 Hz. Besides, the lower rotation speed and frequency of the energy converter of the WEPG-PS (300 rad/s) and induction generator (50 Hz) were able to generate electric power of 7.5 kW. 
Modifikasi Pompa Air Menggunakan Kincir Kecepatan Rendah Sebagai Tenaga Penggerak Jamrud Aminuddin; Nurhayati Nurhayati; Agustina Widiyani
Elkawnie: Journal of Islamic Science and Technology Vol 5, No 1 (2019)
Publisher : Universitas Islam Negeri Ar-Raniry Banda Aceh

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22373/ekw.v5i1.4091

Abstract

Modifikasi pompa air bertenaga mesin telah dilakukan dengan memanfaatkan aliran air lemah. Tenaga penggerak pompa ini adalah kincir dengan rpm (putaran per menit) rendah.  Pompa ini terdiri atas delapan bagian utama, yaitu: rangka, kincir, gear besar, gear kecil, pompa jet, pipa masukkan, dan pipa keluaran. Pompa ini bekerja dengan mengkoversi aliran air debit rendah untuk memutar kincir yang tergandeng dengan gear besar. Selanjutnya, gear besar pada kincir juga berputar diikuti gear kecil pada pompa jet yang dihubungkan dengan rantai. Putaran gear kecil menggerakkan komponen pompa jet yang berputar untuk mengisap dan membuang air. Performa pompa ini dianalisis dengan mengukur debit pada ketinggian tertentu. Berdasarkan analisis yang telah dilakukan, maka diketahui bahwa pompa ini mampu mengangkat air sampai ketinggian 6  meter dengan debit air 0,02 liter per detik.
Persamaan Gelombang Gravitasi untuk Teori Proca yang Digeneralisasi Marliana Marliana; Agustina Widiyani; Azwar Sutiono; Agus Suroso; Freddy P. Zen
Prosiding SNFA (Seminar Nasional Fisika dan Aplikasinya) 2020: Prosiding SNFA (Seminar Nasional Fisika dan Aplikasinya) 2020
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/prosidingsnfa.v5i0.46604

Abstract

Abstract: The direct detection of gravitational waves from binary black holes and neutron stars have been taking a new oportunities to test teori of gravity.The gravitational wave is affected by the modification of a gravity theory during propagation at cosmological distances. By comparing general equation of gravtiational wave and modification of gravity theory, is obtained equation of gravitational wave for the generalized Proca theories. As a result, we find equation of gravitational wave for the generalized Proca theory. We conclude that the massive vector field affected propagation of gravitational wave.  we can use the result to test the generalized Proca theory.    Abstrak: Dengan terdeteksinya gelombang gravitasi secara langsung dari biner lubang hitam dan bintang neutron menjadi kesempatan untuk dapat menguji teori gravitasi yang sedang dikembangkan.Gelombang gravitasi secara umum dipengaruhi oleh modifikasi teori gravitasi selama penjalarannya pada jarak kosmologi. Dengan membandingkan persamaan gelombang gravitasi dengan teori modifikasi yang dikembangkan, diperoleh persamaan umum gelombang gravitasi dari teori gravitasi yang dikembangkan. Pada artikel ini diperoleh persamaan gelombang gravitasi untuk teori Proca yang digeneralisasi. Dapat disimpulkan bahwa fungsi yang mengandung vektor medan masif dapat mempengaruhi gelombang gravitasi. Persamaan ini dapat digunakan untuk menguji teori Proca yang digeneralisasi.
Thin-shell Solution of Chameleon Mechanism in Brans-Dicke Scalar-Tensor Model Azwar Sutiono; Agustina Widiyani; Marliana Marliana; Getbogi Hikmawan; Agus Suroso; Freddy Permana Zen
Indonesian Journal of Physics Vol 33 No 1 (2022): Vol 33 No 1 (2022)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (277.95 KB) | DOI: 10.5614/itb.ijp.2022.33.1.1

Abstract

We investigated the chameleon screening mechanism in Brans-Dicke scalar-tensor theory. We preserved the fundamental premise of the typical chameleon mechanism, which is that the field is huge in high-density environments but essentially free in low-density environments like the solar system. We discovered thin-shell solutions for a static and spherical symmetric body and demonstrated the model’s applicability to local data.
Gravitational Wave Propagation for The Generalized Proca Theories marliana lutan; Agustina Widiyani; Azwar Sutiono; Getbogi Hikmawan; Agus Suroso; Freddy Permana Zen
Indonesian Journal of Physics Vol 33 No 1 (2022): Vol 33 No 1 (2022)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (177.093 KB) | DOI: 10.5614/itb.ijp.2022.33.1.7

Abstract

In general relativity, a gravitational wave propagates with the speed of light, but inthe alternative theories of gravity, propagation speed could deviate from the speed of lightdue to the modification of gravity. Gravitational waves are influenced by modified gravityduring propagation at the cosmological distance. In this paper, we investigate thepropagation of a gravitational wave of the generalized Proca theories by consideringgravitational wave as the gravitational field propagates in spacetime as a wave perturbing flatspacetime. We show that the arbitrary functions G3, G4, and G5 can be the sources ofdeviation of the speed of the gravitational wave.
An Interacting Dark Energy Model with Nonminimal Derivative Coupling in the Parameterized Post-Friedmannian Framework Agustina Widiyani; Azwar Sutiono
Indonesian Journal of Physics Vol 33 No 2 (2022): Vol 33 No 2 (2022)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (312.321 KB) | DOI: 10.5614/itb.ijp.2022.33.2.1

Abstract

We investigation the parameterization of the cosmological model with the nonminimal derivative coupling of a scalar field where gravity is coupled nonminimally with the derivatives of dark energy components in the form of a scalar field. We follow the parameterized post-Friedmannian approach for the interacting dark energy theories. We show how the big number of free functions can be reduced by limiting certain assumptions to a few non-zero coefficients. We only consider the case that the dark sector contains at most second order in time derivatives of the metric and scalar fields. In this paper, we demonstrate their use through an example of the dark sector interactions model and classify them according to the current literature.
FIRST-PRINCIPLES STUDY OF MAGNETIC ANISOTROPY ENERGY IN TWO-DIMENSIONAL FERROMAGNETIC CrI3 Puke Lajaladita Litle Mecci; Annisa Monica; Iin Riananda Br Sinurat; Agustina Widiyani; Abdul Rajak; Indra Pardede
Indonesian Physical Review Vol. 6 No. 1 (2023)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v6i1.191

Abstract

First-principles calculations are increasingly crucial in searching for new materials with customized properties or new functionality. First-principles calculations are superior in speed and cost, and comparable to experiments in terms of accuracy. Two-dimensional (2D) ferromagnetism materials were successfully fabricated experimentally in atomic thin films of CrI3. 2D intrinsic ferromagnetism with perpendicular magnetic anisotropy energy (PMAE) is an encouraging applicant compatible with high-density magnetic storage applications. In this study, spin density functional calculations are investigated on the magnetic anisotropy energy (MAE) in 2D monolayer ferromagnetic CrI3 using a first-principles electronic structure calculation. We include the MAE part calculation from the magnetocrystalline anisotropy energy (MCAE) that comes from the spin-orbit coupling (SOC). In the present calculation, the MCAE part, in addition to a usual scheme of total energy (TE), was evaluated using a grand-canonical force theorem (GCFT) scheme. The MCAE of 2D monolayer ferromagnetic CrI3 is 1.7 meV/unit cell and verified it has an easy-axis perpendicular to the crystal plane, which is a good agreement with experimental measurement. In the latter scheme, employing GCFT, we evaluated atom-resolved, k-resolved, and atomic k-resolved analyses for MCAE can be performed. From the GCFT result, the Cr atom indicates that it is the primary origin of PMAE in the atom-resolved MCAE. The negative MCAE contribution is in points, and the positive MCAE is mainly placed at the line in the 2D first Brillouin zone. Our systematic calculation in this work may also help design an effective structure of monolayer CrI3 in new 2D material magnetic sensor and spintronic device designs.
Numerical Analysis of Energy Converter for Wave Energy Power Generation-Pendulum System Jamrud Aminuddin; Mukhtar Effendi; Nurhayati Nurhayati; Agustina Widiyani; Pakhrur Razi; Wihantoro Wihantoro; Abdullah Nur Aziz; R Farzand Abdullatif; Sunardi Sunardi; Bilalodin Bilalodin; A Arifin
International Journal of Renewable Energy Development Vol 9, No 2 (2020): July 2020
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.9.2.255-261

Abstract

The wave energy power generation-pendulum system (WEPG-PS) is a four-wheeled instrument designed to convert wave power into electric energy. The first wheel is connected to the pendulum by a double freewheel, the second and third are ordinary wheels, while the fourth is a converter component that is axially connected to the electric generator. This design used the Euler-Lagrange formalism and Runge-Kutta method to examine an ideal dimension and determine the numerical solution of the equation of motion related to the rotation speed of the wheels. The result showed that the WEPG-PS' converter system rotated properly when its mass, length, and moment of inertia are 10 kg, 2.0 m, and 0.25 kgm2, respectively. This is in addition to when the radius of the first, second, third, and fourth wheels are 0.5, 0.4, 0.2, and 0.01 m, with inertia values of 0.005, 0.004, 0.003, and 0.1 kgm2. The converter system has the ability to rotate the fourth wheel, which acts as the handle of an electric generator at an angular frequency of approximately 500 - 600 rad/s. The converter system is optimally rotated when driven by a minimum force of 5 N and maximum friction of 0.05. Therefore, the system is used to generate electricity at an amplitude of 0.3 - 0.61 m, 220 V with 50 Hz. Besides, the lower rotation speed and frequency of the energy converter of the WEPG-PS (300 rad/s) and induction generator (50 Hz) were able to generate electric power of 7.5 kW.