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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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KOMPARASI KUALITAS CITRA HASIL REKONSTRUKSI METODE ALGEBRAIC RECONSTRUCTION TECHNIQUE (ART) ADITIF DAN MULTIPLIKATIF (MART) PADA CT SCAN Anam, Choirul; Firdausi, K Sofjan
BERKALA FISIKA Vol 14, No 4 (2011): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

AbstractImage recontruction for CT scan by the methods of additive ART and muliplicative ART (MART) have been carried out using Malab software. The object used is Sheep-Logan phantomwith matrix size 50x50,  used a paralel beam and  angle interval 10, 50, 10,respectively. It is obtained that additive ART produces many artifacts, while MART producesfewer artifacts. Additive ART produces a contras between objects and background with relativelyhigh, while MART produces relatively lower contrast. It is obtained that in the additive ART,interval angle affects the quality of image. This does not happen to MART. So, the MARTreconstruct CT image faster, because it can be obtained relatively good image despite the angleinterval is large.Keywords: Image reconstruction, Additive ART, Multiplicative ART (MART)
DESAIN DAN IMPLEMENTASI MESIN COMPUTER NUMERICAL CONTROL (CNC) BERBASIS ARDUINO SEBAGAI PLOTTER UNTUK MENGGAMBAR GARIS DAN BIDANG SEDERHANA Nugroho, Hafidz; Sumariyah, Sumariyah
BERKALA FISIKA Vol 22, No 4 (2019): Berkala Fisika Vol. 22 No. 4 Tahun 2019
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Abstract

The aim of this research is to design and to implement a computer numerical control (CNC) machine using a cellular phone through bluetooth networks for drawing on a two-dimensional (2D) area of 40 mm x 40 mm. The machine consisted of several main parts, including DVD motor stepper, L293D, servo motor, HC-05, and cellular phone. The control was carried out by using the Blynk application that can be used in two modes, namely automatic (G-code based) and manual modes. The capability of the machine to draw test images were carried out, including linear motion, circular motion, up and down motion, displaying menu, rectangle shape, triangle shape, and circular shape. Results show that the CNC machine can move to draw images according to the commands given in each command mode.Keywords: CNC, Cellular phone, Bluetooth, Blynk
Studi Kualitas Minyak Goreng Dengan Parameter Viskositas Dan Indeks Bias Sutiah, Sutiah; Firdausi, K. Sofjan; Setia Budi, Wahyu
BERKALA FISIKA Vol 11, No 2 (2008): Berkala Fisika
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Abstract

The aim of this research to investigate the quality of palm oil through its viscosity and refractive index before and after used. Viscosimeter Ostwald is used to measure the viscosity and refractive method in prism is used to measure refractive index. The measurement was carried out in room temperature. The samples are fresh oil, and expired oil. Analysis of the quality of palm oil based on viscosity measurement and refractive index show that palm oil that had not been used is the highest value and the palm oil that twice used is the lowest value. Keyword: viscosity, quality of oil
Pengaruh Format Soal Dalam Bentuk Animasi Terhadap Validitas Dan Reliabilitas Tes Pemahaman Konsep Pembiasan Cahaya Suhandi, Andi; Samsudin, Achmad; Setyawan, Agus
BERKALA FISIKA Vol 13, No 2 (2010): Berkala Fisika, Edisi Khusus
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Abstract

This research was conducted to investigate the influence of question format in the form of animation to the validity and reliability tests of understanding the concept of light refraction. For the sake of it has constructed a test of understanding the concept of the refraction of light in an animation format by replacing static pictures and descriptions of the phenomenon of refraction of light propagation in a static format (paper and pencil test) with computer animation. Second test version, the version animated and static versions then tested to 100 students from three high schools in Bandung, which has received the learning material of light refraction. The second test version of the test results are then analyzed to determine the validity and reliability respectively. To see the influence of a test version of the level of validity and reliability, then compare the level of validity and reliability of both versions of this test. The results showed that both the level of validity and reliability tests in levels higher than the animated version of the test in the static version. Level of validity for the second consecutive test version 0.89 (very high) for an animated version and 0.71 (high) for the static version, whereas the level of reliability, 0.92 (very high) for an animated version and 0.78 (high ) for the static version. These results show obvious evidence of the influence of question format in the form of animation on the level of validity and reliability tests of understanding the concept of habituation of light. Keywords: Animation Test Version, Test Version Static, validity, reliability, refraction of light
Analisis Keseragaman Citra pada Pesawat Ultrasonografi (USG) Sudarsih, Kesawa; Setia Budi, Wahyu; Suryono, Suryono
BERKALA FISIKA 2014: Berkala Fisika Vol. 17 No. 1 Tahun 2014
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Abstract

The computer base system to determine uniformity of ultrasonography image quality has been developed at various attenuation(dB) and Time Gain Compensator (TGC).The equipment used in this study was 2-dimensional ultrasonic apparatus and multi-purpose multi-tissue phantom models 040GSE. Data collection was performed by scanning the phantom using a linear transducer with a frequency of 8 MHz. The mean and standard deviation of image density of it ROI calculated used computer base system then analyzed with trendline if the image density value in the range between mean and sd  it means image uniform. The result shows that the uniformity of the image is influenced the value of attenuation and TGC. This value increase proportional with increasing attenuation. For greater value of the TGC the uniformity tends downward. At 45-60 dB  obtained distribution image uniformity sd value is 0.20 and 0.28, and at minimum up to maximum TGC  obtained distribution image uniformity sd value is 0.33 and 0.48. This value can be used for quality assurance reference of USG equipment. Keyword : USG Equipment, Uniformity, Region of Interest, Digital Image Processing
Rancang Bangun Deteksi Alkohol Pada Urine Dengan Sensor TGS 2620 Berbasis Mikrokontroler AT89S51 Sutanto, Heri; Haryowati, Anggraeni Dwi; Arifin, Zainal
BERKALA FISIKA Vol 13, No 3 (2010): Berkala Fisika
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Abstract

The design of alcohol detection in urine using sensors TGS 2620 microcontroller AT89S51 has been done. This device is made with a system that is simple and affordable prices so that it can be used for police and medical laboratories. Alcohol detection in urine is done by using sensors TGS 2620, ADC and the microcontroller. Measured values of the sensor are converted by the ADC and then processed microcontroller to be processed and sent to a computer with RS 232 modules. From the results of engineering manufacture alcohol detection devices in urine obtained test results showing that an increase in the value of sensor output voltage (VRL) at the time the sensor detects the presence of alcohol and research results of alcohol in urine is shown with captions positive or negative urine samples and the percentage content of alcohol .   Keywords: Alcohol, Urine, Sensors TGS 2620, Microcontroller AT89S51.
Optimasi Elektroda Pada Sistem Pembangkit Plasma Non Termik untuk Meningkatkan Kuantitas Benih Mangrove Azam, Much.; Hidayanto, Eko
BERKALA FISIKA Vol 9, No 4 (2006): Berkala Fisika
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Abstract

The Mangrove is the tropics  nature resources that has two aspects, economics and ecology. This plant can be  iradiated   by the corona discharge. It is need to radiate mangrove seed with nitrogen and analize it’s  growt.  For that have need optimations of the electrode on the non thermics plasma generator system  in order to get the effective and the efficient radiations.  The steps of the research are : analize system, make a prototype, test the prototype with simulations, compare  the simulations result with the experiment result and analize the results. From the research can get conclution that: 1) had been succes to make prototype of  the mangrove plant reproduction  system by the corona discharge plasma technology with the point-plant electrode, 2) the simulations result show that  electrical fields shall increase if the distance from electrode has been  decreases, or the voltage of electrode has been  incresed, or the distance among electrode has been decreased  or  the value of the electrode radius.has been opotimum, 3) the result of simulations show that the current density  shall  decrease if distance among electrode has been decreased, 4)for the same distance electrode, the electricel fields of the experiment results  is bigger than the simulations result, because the value of permeability and permittivity medium on the simulation is using the  value of    the vaccum  space.     Key words : the non thermics plasma, iradition, Mangrove
UJI KECEPATAN REKONSTRUKSI CITRA PADA CT-SCAN METODE BACK-PROJECTION (BP) DAN METODE FILTERED BACK-PROJECTION (FBP) DENGAN PEMFILTERAN PADA DOMAIN SPASIAL Ngurah Sutapa, Gusti; Anam, Choirul
BERKALA FISIKA Vol 14, No 2 (2011): Berkala Fisika
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Abstract

Conventional X-ray have many limitations in describing the object being imaged because of overlap on multiple objects on a single line of projection. To overcome this limitation, the object was expossed in several directions, and then the projections from several directions was reconstructed to get cross-section image. The reconstruction method was widely used filtered back projection method as the development of a simple back projection. In this study will be evaluated the speed of the reconstruction for the back projection method and filtered back projection in the spatial domain. It was conducted for the projection angle from 0 to 180 degree, with interval  25, 20, 15, 10 and 5 degrees. In this research the number pixels was 50x50. It was found that the smaller of the interval of the angle projections, then it will get better results, but it takes longer. From back projection and filtered back projection methods, was obtained if the interval of the angle projections a half times smaller, it will take nearly twice as long of time. It was found that the time difference between back-projection and filtered back projection methods is less than 0.1 seconds. Keywords: Image reconstruction, back-projection, filtered back-projection, convolution
Rekayasa Bahan untuk Meningkatkan Daya Serap Terhadap Gelombang Elektromagnetik dengan Matode Deposisi Menggunakan Lucutan Korona Gunawan S.K., Vincensius
BERKALA FISIKA Vol 9, No 1 (2006): Berkala Fisika
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Abstract

The aim of this research is to engineer soft steel  which have low value absorbance of electromagnetic waves become  a material which have higher value absorbance.  The method used is deposition by corona discharge. Corona discharge generated in free space will ionisize air producing nitrogen ion that can be deposite in basic material.  This process will increase the density in the surface of basic materials and then will make the value of linear absorbance constant of basic material become higher.  The optimal result in this research is the raise of  the value of linear absorbance constant by 54,3 % with the time of deposition in 30 minutes, the voltage of electrode 5 kV and  distance between electrodes 6 mm.
SISTEM PENDINGIN MENGGUNAKAN THERMO-ELECTRIC COOLER DENGAN KONTROLER PROPORTIONAL-INTEGRALDERIVATIVE Indrawan, Wisnu; Suryono, Suryono
BERKALA FISIKA Vol 22, No 2 (2019): Berkala Fisika Vol. 22 No. 2 Tahun 2019
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Abstract

The cooling is one of the processes can be used for various types of applications, starting from maintaining food industry products and medical products such as drugs and vaccines. The cooling process now still uses compression-based preservation technology using cooling gas. The types of cooling gas used are R134a and R600a, however the R134a contains HFCs which has been banned for used and the R600a contains HF gas which can reduce the ozone layer. The current study designed hardware and software that is applied to thermoelectric coolers(TEC), i.e. it was designed a device used for the air conditioning system using a thermoelectric cooler with a Proportional Integral Derivative (PID) controller. This system used several tools such as temperature sensors, transistor with TIP31 type, bluetooth module, fan, and ATSAM3X8E microcontroller. In this study, temperature control was carried out based on the desired set-point temperature and temperature of the sensor. From this study, it can be found that the greater value of the voltage given, the greater the value of the Pulse Wave Modulation (PWM) will be produced. The higher value of PWM, the faster the temperature decreases in the cooler. From several tests, it can be concluded that the values of proportional control parameter (Kp) of 2.55, integral control parameter (Ki) of 100 and deferential controlparameter (Kd) of 200, more stable graph is obtained and close to the set-point value, with anerror value of 2.86%.Keywords : Cooling, thermoelectric, gas, controller, temperature

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