How Physics can help in understanding Cardiac Rhythms Predicting & Control of complex oscillatory behavior
Shiuan Ni Liang, Le Duy Manh, Wei Yin Chiang, Pik Yin Lai, C. K. Chan
We discuss our recent theoretical and experimental work in cardiac systems. The first is about the rhythmic variation as the cardiac myocyte cell culture synchronized, and how it can be explained in terms of the frequency enhancement phenomenon in coupled excitable systems. Another work concerns the...
Andri Abdurrochman, Sylvain Lecler, Frédéric Mermet, Joël Fontaine, Bernard Tumbelaka
Photonic jet is a localized sub-wavelength beam generated at the shadow-side surfaces of microscale dielectric cylinders or spheres, when they are illuminated by an electromagnetic wave. We demonstrate the potential of the photonic jets for micro-etching using a nanosecond Near-IR laser (l=1064 nm) that...
Harini Sosiati, Mu'minul Muhamin, Purwanto Purwanto, D. A. Wijayanti, Kuwat Triyana
Nanocrystalline cellulose has been successfully studied by conventional scanning electron microscopy (SEM, JSM-6510LA). Nanocrystalline cellulose was extracted from the natural fibers by the chemical treatments of alkalization and bleaching followed by acid hydrolysis. Alkalization and bleaching resulted...
M. Supardi, Yusril Yusuf, M. Harsoyo
We characterized the four main chain liquid crystal elastomers (MCLCEs) samples using the x-ray diffraction method. The four samples had different concentration of crosslinkers, i.e 8%, 12%, 14% and 16%. There was a relationship between crosslinkers concentration and d-spacing parameter here, namely...
Muhammad Nasruddin Manaf, Iman Santoso, Arief Hermanto
We report the calculation of the Density of States (DOS) in Twisted Bilayer Graphene (TBG) system for low energy range near Fermi level using commensurate rotation of 1.160, 1.790 and 3.480. We obtain a logarithmic behaviour of DOS showing that van Hove Singularities (VHS) are occurred in this system...
Juliasih Partini, Kamsul Abraha, Arief Hermanto, Satoshi Tomita, Matsui Takahiro
Emission of terahertz (THz) radiation as a result of optical rectification of intense femtosecond laser pulses on chiral metamaterials has been observed. The chiral metamamaterials has simplified fabrication design but still capable to exhibit different refractive index for each circular polarization....
Using Symbolic Computation to Inductively Prove Geometric Theorems And Its Implication to The Study of General Relativity
One can reasonably say that we always prove geometric theorems using deductive method. The deductive method is too often used such that we get the impression that there is no other alternative appropriate method. In this paper we will use inductive method. We need many special cases to prove so that...
Stability of Triangular Equilibrium Points of Exoplanetary System HD 4732c by Including Radiation Effect
B. Dermawan, Ibnu Nurul Huda, T. Hidayat, D. Mandey, R.W. Wibowo, I. Tampubolon, J. A. Utama
Exoplanetary system HD 4732 harbors two planets (b and c) in elliptic orbits. The host star (HD 4732) is more energetic than the Sun, while the planets are Jupiter-class. In this work we deal with the triangular equilibrium points with respect to planet HD 4732c because, interestingly, its orbit is located...
Numerical Study of Motion of Sun-Grazing Comet C/2011 W3 (Lovejoy) Affected by Outgassing, General Relativity, and Oblateness Correction Forces
R. W. Wibowo, B. Dermawan, T. Hidayat, D. Mandey, Ibnu Nurul Huda, I. Tampubolon, J. A. Utama
Among comets there are several groups of Sun-grazers. Sun-grazing comets are comets whose motions encounter very closely to the Sun and may eventually plunge into the Sun. Sun-grazing comet C/2011 W3 (Lovejoy) was not expected to survive during close encounter with the Sun on December 16, 2011 due to...
Wahyu Tri Cahyanto, Wahyu Widanarto, Hideaki Kasai
Coadsorption of oxygen (O) and carbon monoxide (CO) on Platinum-alloy (Pt-alloy) surfaces is investigated by using density functional theory (DFT). Simultaneous coadsorption and alloying are considered in order to get more realistic picture of the electrode condition, i.e., in relation with surface CO...
Monte Carlo Simulation of the Nematic-Isotropic Phase Transition of Liquid Crystals under Magnetic Field
M. Warsono, Yusril Yusuf, Pekik Nurwantoro, Kamsul Abraha
The effect of magnetic field on the nematic-isotropic phase transition of liquid crystal was studied by Monte Carlo simulation. The classical spin lattice model was used to describe the liquid crystal systems and the Lebwohl-Lasher potential model. We calculate the energy per spin, the orientational...
This research project is based on vocational skills in physics teaching materials for vocational high school students. Vocational skill-based project was developed to improve the skills of vocational students. The series of student activities, scientific activities and assignments designed so as to help...
Numerical Modeling of 2-D Conductive Heat Transfer and Its Application for the Characterization of Geothermal Systems
Setya Drana Harry Putra, Silvia Jannatul Fajar, Wahyu Srigutomo
A geothermal system is basically a system where heat is transferred from the internal part to the surface of the earth dominantly by conduction, convection, or both. The spatial variation of the magnitude of conductive heat transfer represented by lateral variation of observed surface heat flow values...
A Comparison of Second-Order and High-Order of Finite Difference Staggered-Grid Method in 2D P-SV Wave Propagation Modelling using Graphics Processing Unit
Irchan Bani Hasym, M. Sudarmaji, M. Sismanto
A comparison of second order and high order (4th, 8th and 12th order) of finite difference staggered-grid method on 2D P-SV elastic wave propagation has been conducted. The comparison plot of numerical dispersion and accuracy among each order has been generated to show the stability condition. CUDA C...
Estimation of Frequency Dependent Attenuation of Seismic Wave in Time-Frequency Domain Based on Continous Wavelet Transform (CWT)
M. Sudarmaji, M. Sismanto, M. Waluyo
Frequency dependent attenuation of seismic waves that propagate through the partially fluid saturated porous rock will be observed. The new method for estimation of frequency dependent attenuation will be developed. The frequency dependent attenuation will be calculated in time-frequency domain which...
The 2D Finite Difference Numerical Modelling of P-SV Wave Propagation In Elastic Heterogeneous Medium Using Graphic Processing Unit: Case Study of Mount Merapi Topography, Yogyakarta
Theodorus Permana, M. Sudarmaji
Simulation of seismic wave propagation has been very important way to study the relation between a specific condition of earth medium and seismogram recorded during a seismic event such as an earthquake. In this study, a numerical modelling of P-SV wave propagation in elastic heterogeneous medium has...
Identification of Mass Movement Area in Liwa, Lampung Barat by Using Georadar and Geoelectricity Method
Yusraida Khairani, M. Sismanto, Mohamad Ervan
Georadar method with radar reflection profiling configuration and geoelectrical method with dipole-dipole configuration has been done to determine the lithology, fracture characteristics of weak zone or fault that could potentially result of mass movement in Liwa, Lampung Barat. This research was conducted...
Frequency Analysis and Sismic Vulnerability Index by Using Nakamura Methods For Microzonation at Prambanan Temple and Its Surrounding Area, Yogyakarta Province, Indonesia
Fathul Mubin, Budi Eka Nurcahya
In 2006 a large earthquake ever occurred in the province of Yogyakarta, which caused considerable damage. This is the basis need to investigate the seismic vulnerability index in around of the earthquake zone. This research is called microzonation of earthquake hazard. This research has been conducted...
Eddy Hartantyo, Kirbani Sri Brotopuspito, M. Sismanto
The comparison of their frequency-phase velocity (FV) diagrams from both 8 and 24 channels seismic surface wave active data (MASW) have been carried out. This conducted to show the effectiveness of smaller amounts of geophones for MASW acquitision and comparing the processing FV results. Several data...
Subsurface River Flow Study in Oksibil of Pegunungan Bintang District by Very Low Frequency Electromagnetic Method
M. Sismanto, Salahuddin Husein, Eddy Hartantyo
Pegunungan Bintang district with the capital Oksibil, almost all of its territory is mountains of karst, especially in the west area, people living in the mountain slopes and small valleys in small groups, scattered and isolated. Karst areas, in general, has a lot of subsurface cavities at a developed...
Dhani Herdiwijaya, Johan Arif, M. Zamzam Nurzaman
Solar activities eject high energetic particles, instead of electromagnetic radiation. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle. Solar activities are related to the space weather affecting all planets atmospheric...
Verification on Delay Time Adequacy of RSG GAS (Reaktor Serba Guna - G.A. Siwabessy) Control Elements
The capability of control elements to manage the reactor operation does not merely relay on their negative reactivity worth, but also the speed required to shutdown the reactor when operation state leads to an accident condition. The response speed of control elements is characterized by delay time which...
Design and Implementation of a Capacitance Based Air Bubble Detection System for Hemodialysis Machine
Hemodialysis is one of the medical treatment methods for the patients with end stage renal disease. It is conducted through the use of artificial kidney, located outside of the human body. During the hemodialysis therapy, small air bubbles may infiltrate the blood tubing and coalesce to perform the larger...
Eko Sulistya, Arief Hermanto
Accurate determination of the protons energy in radiotherapy planning can be achieved if the stopping power of protons to specific body tissue are known. The Bethe-Bloch equation greatly aid the understanding of how to calculate the stopping power from the physics point of view, but not so practical...