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Lazuardi Umar
University of Riau
Earth & Planetary Sciences Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics

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PENGUKURAN KETINGGIAN MUKA AIR PADA LAHAN GAMBUT MEMPERGUNAKAN SENSOR ULTRASONIK HCSR-04 Novianti Novianti; Lazuardi Umar
Komunikasi Fisika Indonesia Vol 18, No 1 (2021)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.18.1.69-74

Abstract

Indonesia is a country that has an area of + 14 million hectares of peatlands. Utilization of Indonesia's peatlands is used in various sectors such as plantation and agriculture which increase income in the economic sector so the importance of peatland management. Measurement of the water level in peat is very necessary to maintain the stability of the TMA (water level) of the peat, which is 40 cm. This study uses the ultrasonic sensor HCSR-04  which has a resolution of 0.3 cm with a measurement range of 2 cm to 4 m and is coupled with the Arduino Unowhich is open source so that measurements can be carried out directly using the serial monitor on Arduino-uno. The ultrasonic sensorHCSR-04  is made on a prototype that will be used in TMA measurements both in the field and on a laboratory scale. The measurements show very accurately results with measurement errors 1.2 % with measurements from 100 – 500 mm. measurement error for water temperature  variations of  30 ºC, 35 ºC,and 40 ºC is 1.8%, 6% and than 10%.
IDENTIFICATION OF WHITE NOISE AND 1/f IN CURRENT MIRROR CONFIGURATION BASED ON VDS MOSFET Maria Rosariana Gea; Lazuardi Umar; Rahmondia Nanda Setiadi
JOURNAL ONLINE OF PHYSICS Vol. 7 No. 2 (2022): JOP (Journal Online of Physics) Vol 7 No 2
Publisher : Prodi Fisika FST UNJA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/jop.v7i2.18167

Abstract

Identifying noise in the Current Mirror (CM) circuit is essential to locate noise signals in biosensor applications so that measurements become more accurate and precise. There are two dominant types of noise: white noise, which consists of thermal noise and shot noise, and also low-frequency noise (1/f  noise). The main component of the CM circuit is the BS250 type MOSFET, which works by varying the width of the charge carrier channelcontrolled by the voltage at the gate. When the drain is given a voltage, electrons will flow from the source to the drain which generates the noise.This study was carried out to identify the noise in the CM configuration by varying the reference voltage of MOSFET using the PCI-6221 card data integrated with the LabVIEW program. The reference voltage values ​​used are 1 mV, 10 mV, and 100 mV to determine the effect of the input voltage on the CM circuit noise signal, while the measurement frequency is varied from 0.1 Hz to 100 kHz with a resolution of 0.1 Hz. The results show that the noise characteristics vary with the applied voltage, which will increase at a higher voltage. Analysis of 1/f noise at frequencies up to 0.2 Hz has a gradient increase of up to 10 times for each given voltage value. Based on the value of the data distribution on the white noise measurement, it shows that a voltage of 100 mV produces the highest noise with an average of 3.62 × 10-7 Vrms/Hz1/2. The results of this study are used in the design of CM circuits with minimal noise.
BIOSENSOR FOR THIAMINE DETECTION USING YEAST SACCHAROMYCES CEREVISIAE Leonardus Riski Nainggolan; Siti Rahmawati Ibmar; Sumi Komala; Vira Annisa Rosandi; Lazuardi Umar
JOURNAL ONLINE OF PHYSICS Vol. 8 No. 1 (2022): JOP (Journal Online of Physics) Vol 8 No 1
Publisher : Prodi Fisika FST UNJA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/jop.v8i1.21411

Abstract

Nowadays, people's lifestyles have undergone significant changes, such as decreased physical activity and increased sedentary behavior, as well as an increase in nutritionally unbalanced diets, especially in vitamin B1 (thiamine) intake. Deficiency and excess of thiamine can cause various diseases. Based on this, it is important to know the level of thiamine intake in dietary supplements and medicines. This study used a biosensor with amperometric principles to determine the effect of thiamine on the yeast Saccharomyces cerevisiae as a cell model. Measurements were made by adding controlled vitamins to cell metabolic activity using an amperometric biosensor based on Pt/Ag electrodes. An amperometric biosensor will measure the current from a reduction and oxidation reaction with a constant potential. The effect of adding vitamins to yeast cells was observed in the form of cellular respiration, which was expressed as a parameter of dissolved oxygen level (DO). Vitamins used as samples were given various concentrations of 30 mM, 45 mM, and 60 mM. The addition of thiamine causes an increase in the potential value for each increase in concentration, indicating that DO levels in the cell environment have decreased due to yeast cells consuming O2 during the respiration process. The results of this study indicate that yeast cell-based biosensors can detect variations in the concentration of thiamine for further health applications.
MEASUREMENT OF INFUSION FLOW RATE USING A DROPLET SENSOR BASED ON ARDUINO UNO Khairul Ihsan; Rahmondia Nanda Setiadi; Erman Taer; Lazuardi Umar
JOURNAL ONLINE OF PHYSICS Vol. 9 No. 1 (2023): JOP (Journal Online of Physics) Vol 9 No 1
Publisher : Prodi Fisika FST UNJA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/jop.v9i1.28946

Abstract

A research has been conducted to help the medical staff in the hospital. The purpose of this study is to calculate and regulate the infusion flow rate of the infusion into the patient's body. This research uses an experimental method. The liquid released from the infusion is converted into droplets, which are then detected by the LM393 optocoupler sensor, which consists of three sensors arranged around the detection area by emitting infrared light through a transmitter to detect the shadow of the droplet so that the signal is received by the receiver of the optocoupler sensor. Which is processed with the Arduino Uno microcontroller. The Arduino Uno provides the results received from the sensor and coded using the Arduino IDE software to be displayed on a 16x2-character Liquid Crystal Display (LCD). The sample used in this study was Sodium Chloride (NaCl). The calibration tools performed were droplet sensor test, servo motor test, and Real Time Clock (RTC) DS3231 module test. The results of the detection in the droplet sensor configuration showed a high degree of accuracy, with an error value of 2.414%. so that this research can be implemented in the detection and appropriate management of infusion flow rates. The current testing being carried out is still on a laboratory scale. However, in the future, this system can be developed to monitor infusions in real-time over a longer period of time and using more complex data processing functions.
Co-Authors Erman Taer Khairul Ihsan Leonardus Riski Nainggolan Maria Rosariana Gea Novianti Novianti Rahmondia N. Setiadi Rahmondia Nanda Setiadi Siti Rahmawati Ibmar Sumi Komala Vira Annisa Rosandi