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INDONESIA
BERKALA FISIKA
Published by Universitas Diponegoro
ISSN : -     EISSN : -     DOI : -
Core Subject : Science,
Physics
BERKALA FISIKA adalah jurnal saintifik yang diterbitkan secara periodik 3 bulanan. Jurnal ini memuat kajian-kajian Fisika baik kajian teoretik maupun hasil eksperimen. Jurnal ini juga memberi ruang yang luas bagi kajian – kajian aplikasi fisika dalam bidang teknologi, ilmu-ilmu hayati dan kedokteran.
Arjuna Subject : -
Articles 369 Documents
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METODE AUTOREGRESSIVE INTEGRATED MOVINGAVERAGE (ARIMA) DAN METODE ADAPTIVE NEURO FUZZY INFERENCE SYSTEM (ANFIS) DALAM ANALISIS CURAH HUJAN Wulandari, Rosita Ayu; Gernowo, Rahmat
BERKALA FISIKA Vol 22, No 1 (2019): Berkala Fisika Vol. 22 No. 1 Tahun 2019
Publisher : BERKALA FISIKA

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Abstract

Information of rainfall prediction is important for Indonesian peoples. Many statistical methods can be used in rainfall prediction, they are ARIMA (Autoregressive Integrated Moving Average) and ANFIS (Adaptive Neuro Fuzzy Inference System) methods. The purpose of this study was to compare between ANFIS method and ARIMA method to get rainfall prediction in some periods. The ARIMA method was time series data analysis often used in forecasting. While the ANFIS method was forecasting method based on rarely found time series events that are pure linear or non-linear. Based on this study, the ANFIS method has a good accuracy for time series data analysis compared with the ARIMA method. The ANFIS method has 6.9811 for the result of correlation and 87.29% for the RMSE, while result of correlation for the ARIMA method is 14.037 with 24.92% for RMSE. The ARIMA method is not good for prediction of daily data cases and non-linear data, so that the result is not actual which has a constant and flat for data prediction. Keywords: ARIMA, ANFIS, time series data, linear, non-linear 
OPTIMASI SHIELDING NEUTRON PADA THERMALIZING COLUMN REAKTOR KARTINI Nurlaili, Fidayati; Azam, M.; Firduasi, K. Sofjan; Widarto, Widarto
BERKALA FISIKA Vol 11, No 4 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

Shield optimization and the calculation of neutron flux the coming out of the thermalizing column of the Kartini reactor have been conducted.The neutron flux will decrease exponentially as it passes the thermalizing column. The thermalizing column of Kartini reactor consists of many different kinds of shields, i.e, graphite, lead, paraffin and an empty chamber of air, therefore the neutron flux count that is coming out of the thermalizing column can be calculated and the shields within the column can be optimized to give smaller  neutron flux.Calculation result indicates that the neutron flux coming out of the thermalizing column is 2,681×10-11 cacah cm-2s-1. After optimization, the remaining flux coming out of the thermalizing column is 1,042×10-28cacah cm-2s-1. Key words: thermalizing column, Shield, neutron flux
IDENTIFIKASI ALIRAN AIR INJEKSI DI LAPANGAN TALANG JIMAR REGION SUMATRA MENGGUNAKAN METODE SPONTANEOUS POTENTIAL Fithria I D, Ni'matul; Setyawan, Agus; Yulianto, Tony
BERKALA FISIKA Vol 15, No 3 (2012): Berkala Fisika
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Abstract

Spontaneous-potential observation using amplitude potential method had been done beneathTalang Jimar area. The purpose of observation are to determine the distribution and depth of fluidinjection. Spontaneous-potential which has been corrected then processed using excel and surfer 9 toknow the distibution of its spread, while for the clarified of the deph we used spherical model. Thespontaneous-potential result shows ranging from -40 mV up to 10 mV with direction towards thereference block and a depth of 244,93 meters show.Keywords : Spontaneous‐potential, fluid injection, Talang Jimar, spherical model.
Prototipe Pemanas Air Tenaga Surya Menggunakan Karbon Sebagai Penampung Kalor Wihantoro, Wihantoro; Yanto, Agus; Sunardi, Sunardi
BERKALA FISIKA Vol 13, No 2 (2010): Berkala Fisika, Edisi Khusus
Publisher : BERKALA FISIKA

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Abstract

A solar water heater prototype that fully exploit the nature of black body radiation are made from carbon powder mixed with cement as a thermal energy container material has been created. The phenomenon of physics that underlie the pattern of spread of heat and decrease their physical equations studied in this paper.Construction of heating a metal box containing the installation of planar spiral-shaped copper pipe which is covered with mortar-carbon. The water that fills the copper pipes are supplied by thermal energy from carbon-mortar. Immediately after absorbing heat energy, water density to be different in each section of pipe, causing water circulation by convection between the heater with a water reservoir. The performance of prototype heater is seen from measurements of water temperature rise in the reservoir every 15 minutes. The results are used to determine the average temperature rise of water in every second of it at once to calculate heat energy absorbed by the water in each second. Water temperature in the reservoir increased by 0.0009 ° C per second. At the maximum irradiation conditions, the rate of heat per second that are transferred from a mixture of carbon into the water-cement amounted to 0.075 kW.   Keywords: heat energy, water circulation by convection, heat rate per second
OPTICAL AND MAGNETIC PROPERTIES OF TeO2â‹…ZnOâ‹…Li2O GLASS SYSTEM CONTAINING NATURAL Fe3O4 PARTICLES Widanarto, W; Sahar, M. R.; Shoshal, S. K.; Arifin, R.; Rohani, M. S.
BERKALA FISIKA Vol 16, No 3 (2013): Berkala Fisika
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Abstract

Natural Fe3O4 particles obtained by extracting and manual pulverizing natural iron sand, are doped in the TeO⋅ZnO⋅Li2O glass system by melt quenching technique at 800 °C. X-ray diffraction spectra confirms the presence of iron sand particles with the 33-146 nm diameters and the glassy structure. Vibrating sample magnetometer reveals the pulverized sand exhibits paramagnetic behaviour with magnetic susceptibility of 2.76 × 10^-4 m^3 kg^-1. Incorporation of  the particles in the glasses changes color, thermal stability and improve the glass formation ability through value of Tc-Tg. Ultraviolet–visible measurements show the optical energy band gap decreases by 1.58 eV. Meanwhile, the resonance amplitude of the electron spin resonance spectrum decreases due to the presence of Fe3O4 particles in reducing the unpaired electron spin. The synthesized glasses exhibit paramagneticbehavior.Keywords: Iron Sand, Ferrite oxide, Tellurite, Glass, Optical band gap, Magnetic property, ESR −Tcg
Evaluasi Kinerja Metoda Analisis Pengukuran Neutron (APN) Arifin, Zaenal; Sasongko, Dwi P; Munir, M
BERKALA FISIKA Vol 13, No 1 (2010): Berkala Fisika
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Abstract

Evaluation of Neutron Activation Analysis (NAA) methods performance has been done. The objective is to validate the data form these analysis on the determination of the trace element concentration in the waters and sediments. This evaluation covering test of devices stability, background counting, Figure of Merit (FOM), Critical Level (Lc), Detection Limit (LD), Determination Limit (LQ) and test of quality result. Result show that device in stabil condition  have background counting about 0.0037 to 0.1806 cps, Figure of Merit (FOM) about to 0.0045 to 0.1732 secon. The data result analysis above Critical Level (LC), in LC about 0.07 to 16.42 ppb. Detection Limit (LD) about 0.14 to 32.93 ppb in significant 95% expect Hg obtained LD 1.26 ppb. Determination Limit (LQ) about 0.44 to 100.10 ppb. Test of quality result show that of standardized difference about 15.17% to above 50% and Precision result analysis about 0.01% to 99.00%.   Keywords : NAA Methods, Trace element, devices stability, background counting, Figure of Merit (FOM), Critical Level (Lc), Detection Limit (LD), Determination Limit (LQ) and test of quality result.
PEMBAKARAN FERRALSOL DAN APLIKASINYA UNTUK PENJERNIHAN MINYAK GORENG SISA PAKAI Suhartana, Suhartana
BERKALA FISIKA Vol 10, No 2 (2007): Berkala Fisika
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Abstract

Ferralsol is tropical type land, which exploited as rice field farm and plantation. Other benefit which can be taken away from  this ferrasol  if burned hence will be able to make liquid cleaner material. Composition of ferralsol is ferralsol orthic and ferralsol plinthic. If burned is good for purification liquid material, inorganic and also organic material. In this research result of combustion from ferralsol, used to make clear ex- cooking oil. Result of which scored a number of peroxide go down 12,75 %, number of acid also go down 8,33 %,   by ferralsol, and a number of peroxide go down 19,45 %, number of acid also go down 10,42 % by burning ferralsol   but with both ex- cooking  oil color become clear progressively.   Keyword: ferralsol, liquid cleaner material
RANCANG BANGUN SENSOR KAPASITIF UNTUK LEVEL AIR Zahrotin, Eli; Endarko, Endarko
BERKALA FISIKA 2014: Berkala Fisika Vol. 17 No. 4 Tahun 2014
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Abstract

Capacitive sensor for measuring water level has successfully been fabricated and characterized. Capacitive water level sensor has been fabricated using coaxial cylinder with an inner and outer radius at 0,955 and 1,435 cm, respectively. The cylinders have a length of 82 cm. The study was used water and air as dielectrics for filling in the space of two cylinders. The design of sensor based on the principle of cylindrical capacitor with two dielectrics. Measurements of water level repeated three times to ensure an accuracy of data. The ruler was used as calibrator for measurement of water level. The result showed that the capacitive water level sensor can be used to measure water level with the maximum of standar deviation around 1,40, when the system was used to measure increased water levet at 50 cm and standar deviation minimum at 0,01 occured when it was used to measure decreased water level at 0 cm. Range of measurement was 0,16 -78,99 cm with an average error value when measurements of increased and decreased water level was 2.30 and 1.75%, respectively. Keywords: water level, capacitive, coaxial cylinder.
Sampul Januari 2011 Januari 2011, Sampul
BERKALA FISIKA Vol 14, No 1 (2011): Berkala Fisika
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Abstract

Sampul Januari 2011
Respon Non Linier Sifat Optis Larutan MgSO4 Firdausi, K. Sofjan; Azam, Much.; Romadhona, Thithit; Abadi, Prayitno
BERKALA FISIKA Vol 9, No 3 (2006): Berkala Fisika
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Abstract

A response of nonlinear optic of several salt solutions in external magnetic field has been studied. An altered magnetic field varies from 0 until 0,2T used to induce samples, and then change of polarization angle b is measured by polarizators, where the direction propagation of laser is perpendicular to the direction of B. Various concentration of solution is used at 5% until 35%. Our experiment shows that the graphs of b vs. B are still linear for mineral water and NaCl solution. However, for MgSO4 solution, we obtained polynomial tendency of this graph. At 20% until 35% of concentration of this solution it has polynomial in third order. Keywords: Nonlinear optics, change of polarization angle, external magnetic field.

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