2016-17 UNOPA Annual Report

Sensor konsentrasi glukosa dengan prinsip macrobending pada serat optik multimode step-index dengan variasi panjang kupasan 2 cm, 3 cm, dan 4 cm. Setiap panjang kupasan dilengkungkan dengan diameter kelengkungan 2 cm, 3 cm, dan 4 cm. Larutan glukosa yang diuji memiliki konsentrasi 0% (aquades), 5%, 10%, 15% dan 25%. Sumber cahaya yang digunakan LED dengan panjang gelombang 660 nm dan detektor yang digunakan yaitu BF5R-D1-N yang telah dikalibrasi dengan menggunakan Optical Power Meter. Dari hasil yang diperoleh semakin besar diameter kelengkungan serat optik semakin besar pula daya keluaran, dan semakin panjang daerah kupasan semakin kecil daya keluaran

Desain Sensor Konsentrasi Larutan NaCl Menggunakan Serat Optik Moda Jamak dengan Model W-System

Telah didesain sensor konsentrasi larutan NaCl berbasis serat optik mode jamak dengan model W-System. Dalam pengkarakterisasiannya digunakan detektor BF5R-D1-N yang terdapat ligh emiting diode (LED) sebagai sumber cahaya dengan panjang gelombang 660 nm dan phototransistor sebagai detektor penerima cahaya tersebut. Dengan menganalisa nilai absorbsi pada panjang gelombang ultra violet dan cahaya tampak, Indek bias larutan NaCl, dan rugi daya yang dialami sensor ini akibat microbending, bending, dan scattering. Didapatkan besarnya rugi daya yang dialami sensor sebanding dengan besarnya kosentrasi NaCl yang diberikan. Pemberian jarak antar kaki memberikan perbedaan sensitifitas pada pengukuran dan nilai sensitifitas maksimum pada jarak 2,5 cm. Sistem kerja sensor juga ini mampu menghitung konsentrasi larutan NaCl dengan jangkauan 0,0 – 5,0 Molar dan akurasi hingga 0,025 Molar

The Influence of Multi-frequency Current Injection in Image Reconstruction for Two-Dimensional High-Speed Electrical Impedance Tomography (EIT)

The image reconstruction for two-dimensional high-speed Electrical Impedance Tomography (EIT) has been successfully studied with multi-frequency current injection. The aim of this study is to get the best image reconstruction under the influence of multi-frequency current injection of this EIT system. In this method, we used current injection at 1 mA with varies of frequency in the range 10 to 50 kHz injected at the practical phantoms with 16 electrodes. Polyvinyl chloride (PVC) cylinder was put in the practical phantom as the anomaly. Then, The boundary voltage of the practical phantom was measured by the voltage measurement circuit. After that, it processed in the computer with Gauss-Newton Algorithm to got image reconstruction. The result showed that the best image reconstruction was achieved at 10 kHz of frequency current injection. The best image reconstruction had more accuracy of shape, position and electrical properties of an anomaly in boundary phantom than another image reconstruction result

Analysis of Feedback Parameter with Vibration Sensor on Signal Self-Mixing Interferometry

In the research aims to analyzed feedback parameter on Self-Mixing Interferometry (SMI) signals. It is because the feedback parameter is one of the determined parameters in SMI vibration sensor research. The experimental apparatus consists of a laser diode as the light source, mirror as a target, collimator as light alignment, and PLX-DAQ as data acquisition executed by Arduino Uno. The principle of data retrieval with the manner of the light source is directed exactly perpendicular to the vibrating target, then reflected and arrested by the detector (photodiode) contained in the laser diode. Light arrested by the photodiode in the form of optical value then automatically converted into voltage value displayed on a personal computer (PC). This feedback on SMI is obtained by variation of the vibration frequency given to a target. The variation of vibration given is 10-100 Hz with 10 Hz increment and each frequency is taken 1000 data. Based on the research that has been done then results obtained at the frequency of 10-30 Hz feedback does not appear because the vibration small so that the vibration sensor is less than optimal. Feedbacks appear at frequencies 40 Hz and 50 Hz but are clearly visible at frequencies 50 Hz. While at 60-80 Hz frequency feedback begins to disappear. The existence of feedback on frequency 50 Hz indicated that vibration sensors on SMI can be applied to industry and medical fiel

Desain Sensor Konsentrasi Larutan NaCl Menggunakan Serat Optik Moda Jamak dengan Model W-System

Telah didesain sensor konsentrasi larutan NaCl berbasis serat optik mode jamak dengan model W-System. Dalam pengkarakterisasiannya digunakan detektor BF5R-D1-N yang terdapat  ligh emiting diode (LED) sebagai sumber cahaya dengan panjang gelombang 660 nm dan phototransistor sebagai detektor penerima cahaya tersebut. Dengan menganalisa nilai absorbsi pada panjang gelombang ultra violet dan cahaya tampak, Indek bias larutan NaCl,  dan rugi daya yang dialami sensor ini akibat microbending, bending, dan scattering. Didapatkan besarnya rugi daya yang dialami sensor sebanding dengan besarnya kosentrasi NaCl yang diberikan. Pemberian jarak antar kaki memberikan perbedaan sensitifitas pada pengukuran dan nilai sensitifitas maksimum pada jarak 2,5 cm. Sistem kerja sensor juga ini mampu menghitung konsentrasi larutan NaCl dengan jangkauan 0,0 – 5,0 Molar dan akurasi hingga 0,025 Molar

Characterization Speckle Effect on Measurement of Blood Flow Using Sensor Based on Self-Mixing Interferometry

The applications of Self-Mixing Interferometry (SMI) have been popular in many fields, including biomedical signals. The self-mixing effect occurs from the coherent back-coupling of the reflected or scattered lights from a target surface. The reflected lights will be detected by a photodiode which has been integrated in one device with the laser. That's why the SMI sensor is quite practical, affordable and simple. However, SMI has the serious problem with the presence of speckle effect in measured signal. The speckle effect produced by the human tissue is called “biospeckles.” The biospeckles observed from the skin tissues contain information about the blood flow in dermal capillarities, heartbeat, and others. These biospeckle patterns cause random modulations that will be detected as random amplitude and spectrum by photodiode. In this paper we present a technique to characterize speckle effect on measurement of blood flow in fingertip using sensor based on Self-Mixing Interferometry (SMI). We used a laser diode 785 nm as a light source and a constant current of 70 mA as a current source which is irradiated on the skin tissue in the fingertip. Then, the backscattered light reenters the laser cavity and it will be detected by photodiode. The SMI signal with speckle effect will be processed by Continuous Wavelet Transform for reconstruction and detection fringe. Signal processing results show that the number of detected speckle fringes depends largely on determining the number of wavelet waves and the scale used. The fringe pattern resulting from the reconstruction of the signal can be used to determine the frequency of speckles due to object movement. The average speckle frequency of fingertip is 0,5-0,7 H

Analisis Sensor Regangan dengan Teknik Pencacatan Berbasis Serat Optik Multimode Step-Index

Penelitian sensor regangan dengan variasi pencacatan pada serat optik multimode step index tipe FD-620-10 yang memiliki diameter serat 1 mm telah dilakukan. Cladding serat optik diberikan pencacatan dengan variasi pencacatan sebanyak 1 sampai 5 buah dengan lebar pencacatan 3 mm dan jarak antar pencacatan dibuat dengan ukuran yang sama yaitu sebesar 1 cm. Untuk mengetahui besaran daya keluaran akibat regangan digunakan LED (Light Emitting Diode) panjang gelombang 660 nm sebagai sumber cahaya, microdisplacement, dan BF5R-D1-N sebagai detektor cahaya. Pengukuran sensor regangan berbasis serat optik menunjukkan bahwa sensitivitas dengan pencacatan lebih bagus dari fiber optik normal

Optically Switched Frequency for Reconfigurable Dipole Antenna Using Photodiode Switches

The design, fabrication, and measurement of reconfigurable antenna using photodiode switches has been investigated. The antenna had dimension 104 mm x 41 mm x 1.6 mm and FR4 substrate with relative permittivity4.8. It structure was Coplanar Stripline (CPS) dipole. Two photodiodeshad assembled on gap in both dipole arms, which was activated by 600 nm red laser. The unilluminated state, antennahad resonant frequency 800 MHz with RL -32 dB, 2225 MHz with RL -12.5 dB, 3320 with RL -14.1 dB. Meanwhile for the illuminated state, antennahad resonant frequency and return loss shifting to 800 MHz with RL -32 dB, 2225 MHz with RL -12.5 dB, 3320 MHz with RL -14.1 dB.This condition caused low impedance and longer dipole arm. If dimension size increases, resonant frequency will decrease. So, there was shifting frequency and return loss at under illuminated by laser

Desain Closed Photobioreaktor Chlorella Vulgaris sebagai Mitigasi Emisi CO2

Telah dilakukan desain closed photobioreaktor yang sesuai dengan perkembangan mikroalga Chlorella Vulgaris pada closed fotobioreaktor. Penelitian ini menggunakan jenis flat-plate berdimensi 14x15x20 cm dengan efektivitas media kultur 2500 ml dan sumber cahaya lampu Tungsten Halogen 20 Watt 220 Volt sebanyak dua buah yang diletakkan pada sisi kanan dan kiri reaktor dengan intensitas cahaya 1000 lux. Penelitian ini menggunakan dua buah fotobioreaktor yaitu jenis I tidak disuplay dengan CO2 dan jenis II disuplai dengan CO2 sebanyak 15 % dengan kepadatan sel awal kultur Chlorella Vulgaris 14,6857 x 105 sel/ml kemudian pengamatan selanjutnya dilakukan setiap hari menggunakan Haemocytometer. Pengambilan data konsentrasi O2 dilakukan setiap hari sebanyak 3 kali pada lama penyinaran 1, 4, dan 7 jam dengan menggunakan sensor gas O2 KE-50. Nilai ∆ konsentrasi optimum O2 pada fotobioreaktor I terjadi pada hari ke-2 yaitu 0,68% dan pada fotobioreaktor II 0,54%