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Komunikasi Fisika Indonesia

JKFI
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Published by Universitas Riau

ISSN : 14122960 EISSN : 2579521X DOI : 10.31258/jkfi

Core Subject : Science, Engineering,

Earth & Planetary Sciences Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics

KFI mempublikasikan artikel hasil penelitian dan review pada bidang fisika, namun tidak terbatas, yang meliputi fisika murni, geofisika, plasma, optik dan fotonik, instrumentasi, dan elektronika, dan fisika terapan (aplikasi fisika).

Arjuna Subject : Fisika dan Astronomi - Fisika dan Astronomi (Lain-Lain)

Articles 390 Documents

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STUDI AWAL GRADING BUAH SAWIT DENGAN BANTUAN INJEKSI TEGANGAN LISTRIK SEARAH Andri Saputra; Wahyu Candra; Yan Soerbakti; Romi Fadli Syahputra; Defrianto Defrianto; Saktioto Saktioto
Komunikasi Fisika Indonesia Vol 16, No 2 (2019)
Publisher : Universitas Riau

Maturity progress of palm fruit is greatly depending on the availability of nutrients and environments. Determining maturity level of palm fruit is important to evaluate the quality of palm oil fruits. The younger or too mature fruits will produce poor quality of crude palm oil (CPO). An appropriate devices are needed that can measure the level of fruit maturity so that uniformity of maturity grade can be carried out to obtain high quality CPO. This research provides a preliminary study of voltage change on the surface of oil palm seeds which subjected by electric potential. The low directional voltage (DC) injection treatment, ~ 10V, was applied to investigate the impact of applied voltage on palm oil seeds with three different levels of maturity, i.e. immature (young), ripe and over ripe . The results shown that oil palm fruit quite quickly responds to injection of DC applied voltage with different responding voltage. This responding voltage tends to increase with increasing maturity levels, but decreases for over ripe fruit which has falling down and starting to dry out.

SEGMENTASI CITRA PARU-PARU MENGGUNAKAN METODE KONTUR AKTIF DENGAN VALIDASI ROC Sintha Syaputri; Zulkarnain Zulkarnain
Komunikasi Fisika Indonesia Vol 16, No 2 (2019)
Publisher : Universitas Riau

Segmentation is the process of separating parts of objects from the background by dividing images that have different object intensities with each other such as in imaging of body parts. Active contour segmentation was used for medical imaging that resistant to noise around objects. This study used 5 chest X-Ray images, specifically to the lungs with a grayscale format measuring 256 x 256 pixels, through the preprocessing process and filtering a Gaussian filter, each image was inputted to the R2015a version of the matlab GUI program. Then the segmentation had done by using the active contour method. In this method a curve in the form of a small circle was placed on the edge of object to be segmented. The curve will move according to the shape of the outer edge of the lung based on the values of active contour parameters such as Alpha, Beta, Gamma, Kappa, WEline, WEdge, WEterm and Iteration. Validation was done by using the ROC (Receiver Operating Characteristic) method and were obtained an average percentage with an accuracy value of 96.26%, a specificity of 96.47% and a sensitivity of 76.54%.

KAJIAN SUSEPTIBILITAS MAGNETIK PASIR BESI PANTAI ARTA SEBAGAI FUNGSI JARAK DARI TEPI LAUT Irma Novalia; Erwin Erwin
Komunikasi Fisika Indonesia Vol 17, No 1 (2020)
Publisher : Universitas Riau

Magnetic Susceptibility measurements and the identification of elements of iron sand from Arta beach of Pariaman West Sumatera have been done. The samples were dried first under the sun before the separation between magnetic particles of iron sand and non-magnetic particles using Iron Sand Separator. Identification elements of iron sand was done using X-Ray Fluorescence. The total value of magnetic induction was measured using a magnetic Pasco probe PS-2162 using a solenoid 2000 coils turns, dimensions of 3 cm in diameter and 10 cm in length. The solenoid was given an electric current with variations ranging from 2 A – 8 A. The distance between magnetic probe and one end of solenoid was kept constant that was 1 mm. The next experiment was to measure the function of distance ranging from 1 – 5 mm with constant applied current of 8 A. When electric current increase then the total magnetic induction also increase. Total magnetic induction value decreases as the distance increases. Magnetic susceptibility was calculated based on total magnetic induction and magnetic induction of core currents with constant current of 8 A and distance of 1 mm. The value of magnetic susceptibility obtained in the range (2164,71-3159,99)x10-5 which consist of ilmenite mineral (FeTiO3; Antiferromagnetic).Keywords : iron sand, magnetic suseptibility, iron sand separator, solenoid, magnetic induction, and x-ray fluorescence.

EFEK GELOMBANG TSUNAMI ACEH 2004 PADA GANGGUAN IONOSFER BERGERAK SKALA MENENGAH DARI PENGAMATAN JARINGAN GPS SUMATRA Asnawi Husin; Buldan Muslim
Komunikasi Fisika Indonesia Vol 16, No 2 (2019)
Publisher : Universitas Riau

Medium Scale Travelling Ionospheric Disturbance (MSTID), thought to be manifestation of atmospheric gravity wave (AGW) in the ionospheric altitude that propagates horizontally and effects on in the electron density structure of ionosphere. These atmospheric gravity waves sourced from lower atmospheric activities such as typhoons, volcanic eruptions and tsunamis. Wave energy by its coupling induction process can travel to the ionosphere region. It has been understood that the TID's wave structure have an impact on the propagation of radio waves in the ionosphere so that it will affect the performance of navigation satellite-based positioning measurements. Based on Aceh tsunami in December 2004, this study aimed to investigation of the induction of atmospheric gravity waves in the ionosphere using total electron content (TEC) data from the Sumatra GPS network (Sumatra GPS Array, SUGAR). The detection technique of TEC changes due to AGW induction with a filter to separate medium scale disturbance at the ionospheric pierce point at an altitude of 350 km (IPP, Ionospheric Pierce Point). The results show the horizontal wavelength of a medium-scale TID around 180 ± 12 Km with a velocities of around 376 ± 9 ms-1. Based on two-dimensional map, the TID moves to the southeast.

SIMULASI POLA ALIRAN FLUIDA DALAM DAERAH DENGAN BATAS TIDAK TERATUR MENGGUNAKAN METODE ELEMEN HINGGA Defrianto Defrianto; Dwi Putri Cahya Safitri
Komunikasi Fisika Indonesia Vol 16, No 1 (2019)
Publisher : Universitas Riau

Research of ideal fluid flow on irregular domain by variation mesh has been done. Laplace equation was used to model velocity potential and the gradient was used to velocity. Boundary condition for inlet was chosen to be 15 , while for outlet was 30 and Neumann boundary condition on lateral side. The developed model shows that uniform flow was happened on straight channel and free vortex on the curved one. The analytical and computational calculation has similar results, that is 23.7787 and 23.7792 The percentage of the difference is 2.8 wich is very small, therefore this method is accurate enough to model pattern of ideal fluid flow on irregular domain.

PERBANDINGAN NILAI SUSEPTIBILITAS MAGNETIK AIR LAUT MENGGUNAKAN METODE QUINCKE DI PANTAI SUMATERA BAGIAN TENGAH Muhammad Zul Ilmi Rangkuti; Salomo Salomo; Usman Malik
Komunikasi Fisika Indonesia Vol 17, No 1 (2020)
Publisher : Universitas Riau

Telah dilakukan penelitian perbandingan nilai suseptibilitas magnetik air laut di pantai barat dan timur sumatera bagian tengah menggunakan metode Quincke. Jumlah sampel yang diambil dari penelitian ini sebanyak 500 ml tiap-tiap lokasi. Jumlah titik lokasi sampel adalah 24 didapatkan dari tiga pantai barat sumatera bagian tengah dan satu pantai timur. Metode yang digunakan untuk pengambilan sampel adalah fungsi jarak dengan rentang 300 m dari tepi pantai. Induksi magnetik solenoida diukur menggunakan Probe Magnetic Pasco Ps-2162 dengan dua buah solenoid 3000 lilitan. Ketika arus dinaikkan induksi magnetik semakin besar. Nilai suseptibilitas magnetik ( χ ) air laut pantai barat menunjukkan rentang -1,04 x 10-5 sampai -4,53(x 10-5). Sampel merupakan bahan diamagnetik. Nilai suseptibilitas magnetik ( χ ) air laut pantai timur menunjukkan rentang -0,5 x 10-5 sampai -1,46(x 10-5).sampel merupakan bahan diamagnetik. Salinitas dan pH menyebabkan perbedaan nilai suseptibilitas magnetik air laut.

ANALISA PENGARUH GAYA ELEKTROSTATIK PADA SPEKTRUM PENCITRAAN RESONANSI MAGNETIK (MRI) DALAM JARINGAN BIOLOGI Salomo Salomo; Nova Lestari; Muhammad Hamdi
Komunikasi Fisika Indonesia Vol 16, No 1 (2019)
Publisher : Universitas Riau

A study of magnetic core resonance imaging modeling of biological tissue has been carried out in analyzing the effect of electrostatic forces with computational approach. This analysis aims to look at the effect of electric and magnetic force on the spectrum of breast cancer tissue. Physical parameters were determined using the modeled wave equation with the application of mathematical wolfram software 9. Computational or modeling results obtained 6 variations of the MRI spectrum showing the peak magnitude of the electric and magnetic spectrum changes by varying the resolution and distance. This is evidenced from the maximum resolution range ie the peak of the electric field spectrum at amplitude 25 a.u is at a concentration of 5 ppm. Resolution of spectrum peak medium is at concentration of 3-4 ppm whereas minimum resolution has 4 peak spectrum that is at concentration 1-2 ppm, 2-3ppm, 3-4ppm and 4ppm. the result of MRI spektrum for distance variation resulted in spectrum change, further reduced the distance then the mri spectrum in magnetic and electric field approaching spin 1.

ANALISIS SIFAT MAGNETIK DAN STRUKTUR PARTIKEL PASIR BESI PANTAI ARTA PARIAMAN SUMATERA BARAT MENGGUNAKAN BALL MILLING Wita Yulia; Erwin Erwin
Komunikasi Fisika Indonesia Vol 16, No 2 (2019)
Publisher : Universitas Riau

Analisys of magnetic properties and structure of particles of iron sand of Arta, Pariaman beach West Sumatra. Has been conducted the iron sand samples were dried, then the iron sand separation process was carried out using Iron Sand Separator (ISS). Next, the sample was milled for 30, 60 and 90 hours. The separation between magnetic particles and non magnetic particles was done using Neodymium Iron Boron (NdFeB) magnet. Magnetic induction measurements were carried out using Pasco PS-2162 Magnetic Probe which measured the total magnetic induction of solenoid (solenoid with core sample and milled sample(consentrate II)) as a function of electric current of 1-8 A for a fixed distance of 1 mm. Identification of the content of elements contained in iron sand before and after processing with Ball Milling for 90 hours was carried out using X-Ray Fluorescence (XRF). The phase of magnetic particles processed by Ball Milling was determined using X-Ray Diffraction (XRD). The calculation results show that the magnetic susceptibility of the sample increases with increasing Ball Milling time, from (69426,19 × 10-5 – 80332,13 × 10-5). These values are in the interval 220 - 380.000 × 10-5of the Ilmenite mineral. The magnetite phase appears more than the maghemite phase and the hematite phase after Ball Milling for 90 hours. The particle size of magnetik particle decreases as milling time increase, this trend is confirmed by the result of XRD.

PEMETAAN NILAI SUSEPTIBILITAS MAGNETIK PASIR PANTAI GANDORIAH PARIAMAN SUMATERA BARAT Putri Vanera Puspita; Erwin Erwin
Komunikasi Fisika Indonesia Vol 17, No 1 (2020)
Publisher : Universitas Riau

Mapping of magnetic susceptibility values of sand of Gandoriah beach, Pariaman West Sumatera has been carried out. The composition of sand beach was identified using X-Ray Fluorescence Spectroscopy (XRF) and the map of magnetic susceptibility and mass susceptibility of the sample were determined using Software Surfer 11. The samples were collected based on grid technique from 25 points location. The separation between magnetic particles and nan magnetic particles was done using iron sand separator for 1 time process.The result of the calculation of the magnetic degree of the sample using Iron Sand Separator for 1 time prosess showed that the values are in the range of 3,88 %-5,12 %. Magnetic and mass susceptibility values of the sample are in the range of (603,3-1351,46)×10-5 and (112,76–1086,85)×10-8 m3/Kg respectively. Magnetic and mass susceptibility of the concentrate (product of iron sand separator) are in the range of (1367,55–2155,9)×10-5 and (927,41–1774,28)×10-8 m3/Kg respectively. These values are in the range of Ilminate mineral that is (220-380000)×10-5 and (46-80000)×10-8 m3/Kg respectively. The percentage of Fe and Ti increases from 6,276 % to 54,549 % and from 0,441% to 5,102% respectively after being processed by iron sand separator. The results also showed that magnetic susceptibility values increase toward the sea water.

KAJIAN APLIKASI PANTULAN SINYAL GNSS UNTUK PEMANTAUAN KETINGGIAN PERMUKAAN AIR LAUT Buldan Muslim; Charisma Juni Kumalasari; Novie Chiuman; Muhammad Ichsan Fadhil Arafah
Komunikasi Fisika Indonesia Vol 16, No 2 (2019)
Publisher : Universitas Riau

Design and experiment of ocean current power generation system have been carried out using the Bach In Indonesia, the tsunami early warning system only applies the earthquake and hydrosphere relationship model to predict tsunamis. To date, no tsunami detector has used radar or GNSS technology. GNSS technology can be applied as an early warning system for tsunamis, provided that tsunamis are caused by earthquakes greater than 7 magnitudes, occur 70 kilometers below sea level, and are caused by normal faults. This could be an alternative to Bouy GNSS which is expensive to install and maintain, especially for countries with vast oceans such as Indonesia. In this paper, a review of the application of GNSS signal reflection was carried out using one International GNSS Service (IGS) station, JOG2, and one Continuously Operating Reference Station (CORS), CLSA, each located in Java and Sumatra to investigate the availability of sea level monitoring in Indonesia. Determination of sea level is obtained from two methods, the GNSS signal phase data analysis method and the GNSS Signal-to-Noise Ratio (SNR) data analysis method. Both methods use reflected GNSS signals or multipath effects to obtain sea level. The results of the study show that the number of satellites that pass through Indonesia every 15 minutes is enough to get sea-level data every 15 minutes to one hour. This shows that it is possible to apply the multipath effect to obtain sea level information in Indonesia to detect tides and tsunamis as part of the tsunami early warning system in Indonesia.

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Usman Malik

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Home Page

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Contact Name Usman Malik

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Editorial Address Jurusan FMIPA Universitas Riau Kampus Bina Widya Km 12,5 Simpang Baru Pekanbaru

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Contact Name
Usman Malik

Contact Email
usman.malik@lecturer.unri.ac.id

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+62811756227

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kfi@ejournal.unri.ac.id

Editorial Address
Jurusan FMIPA Universitas Riau Kampus Bina Widya Km 12,5 Simpang Baru Pekanbaru

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Riau

INDONESIA