POLY ORGANIC POLYMER (3-HEXYLTHIOPHENE) P3HT as LIGHT SENSITIVITY in PROTOTYPE DYE-SENSITIZED SOLAR CELLS (DSSC)

This research aims to review the characteristic of the nature of electricity polymer material poly(3-hexylthiophene) P3HT against increasing efficiency solar cells based on dye-sensitized solar cells (DSSC). The testing sample has done electricity P3HT el-kahfi 100/ I-V meter. The optical properties use spectrophotometer UV visible 1601 PC and characterizing IV DSSC use Keithley 2600 a type. The absorbance of P3HT polymer 1% has an absorption peak in the wavelength range of 300-650 nm. Thus the P3HT polymer material can absorb light in the visible wavelength range. The electrical properties of P3HT 1% indicate that the material has a response to light. In bright conditions, P3HT 1% shows a conductivity of 3.7x10-3Ω-1m-1 and in dark conditions 2.2x10-3Ω-1m-1. Meanwhile, Pt (Hexacloroplatinic IV) Platina as the opposing electrode can improve the performance of DSSC, which is because Pt (Hexacloroplatinic IV) functions as a catalyst to accelerate the redox reaction with electrolytes. The use of P3HT 1% can improve DSSC performance. DSSC using 1% P3HT and using Pt (Hexacloroplatinic IV) as the opposing electrode produced an efficiency value of 1.8x10-2%.

Detection of Mercury Ions in Water using a Plastic Optical Fiber Sensor

Research has been carried out on the detection of mercury ions in water using plastic optical fibers. Detection of mercury ions is done by immersing the optical fiber sensor in the HgCl2 solution, where both ends of the sensor are connected to an LED and a phototransistor. LED as a light source will emit light along with the optical fiber which will be received by the phototransistor. The optical light received by the phototransistor is converted into an electric voltage and given a gain in the differential amplifier. The output voltage in the form of an analog signal is converted into a digital signal on the Arduino UNO so that it can be read on a computer. The optical fiber as a sensor is made in two configurations, namely U configuration and spiral spring configuration. The jacket and the fiber optic cladding are peeled off and then covered with chitosan. Each configuration will be given a variation of the curve to analyze the characteristics of the sensor. The curvature can cause a large power loss resulting in attenuation of the light intensity of the LED received by the phototransistor. Apart from the effect of indentation on optical fibers, the output voltage measurement results are also influenced by the level of HgCl2 concentration. The best measurement results for mercury ion sensors in water using plastic optical fibers are obtained in a spiral spring configuration with a chitosan cladding with a variation of 6 coils which has a sensitivity of 104.065 mV/ppm.

RANCANG BANGUN SISTEM PENDETEKSI PENYERAPAN GAS KARBONDIOKSIDA (CO2) OLEH TUMBUHAN MENGGUNAKAN SENSOR MH-Z19

Pengukuran serapan CO2 pada tumbuhan sangat penting, untuk mengetahui tumbuhan-tumbuhan yang memiliki kemampuan menyerap CO2 dalam jumlah besar. Kemampuan serapan CO2 suatu tumbuhan dapat diukur dengan memanfaatkan suatu jenis sensor yang dapat mendeteksi atau mengukur konsenstrasi CO2. Pada penelitian ini dirancang dan dibuat suatu perangkat sistem pendeteksi serapan CO2 pada tumbuhan. Perangkat ini terdiri dari sensor MH-Z19, modul Arduino Uno, modul data logger dan chamber daun. Untuk pengujian sistem pengukuran serapan CO2 digunakan beberapa sampel uji yaitu udara bebas, oksigen dengan kadar 95% dan CO2 buatan. Pengambilan data serapan CO2 dilakukan selama satu jam pada pukul 08.00, 10.00, 12.00, 14.00 dan 16.00 WITA dengan pengulangan sebanyak lima hari. Hasil pengukuran menunjukkan pola yang sama. Hal ini ditunjukkan dengan terlihatnya nilai konsentrasi CO2 mengalami penurunan selama satu jam pengukuran. Walaupun tren data menunjukkan kecenderungan yang sama, namun penyerapan yang paling baik terjadi pada hari pertama, ketiga, keempat dan kelima. Untuk hari pertama, ketiga dan kelima kondisi cuaca sangat cerah sehingga penyerapan CO2 yang terukur mencapai 500 ppm - 650 ppm, sedangkan pada hari keempat kondisi cuaca sedikit berawan sehingga penyerapan CO2 hanya mencapai 700 ppm. Sistem yang telah dibuat memiliki presisi pengukuran rata-rata dalam rentang waktu lima hari diatas 80%. Presisi dari sistem pendeteksi dalam rentang 88,67%-94,14%.

PHYSICAL DISTANCING ALARM SYSTEM BASED ON PROXIMITY SENSOR AND MICROCONTROLLER

Keeping an interaction distance between 1 to 2 m is one of the health protocols during the COVID-19 pandemic. This attempt was made to reduce the spread of the Coronavirus. On the other hand, this health protocol activity is often overlooked, whether intentionally or not. According to the mechanism of the Coronavirus spreading in the form of droplets that comes out during communication, sneezing, or coughing, maintaining distance can be the best effort to minimize the transmission of this virus. Therefore, the availability of a simple, accurate and user-friendly physical distancing alarm system could be a solution in the implementation of this health protocol. In this study, a prototype of a physical distancing alarm based on a distance sensor and a microcontroller in the form of an identity card was developed. Several steps are conducted in developing of this system, namely designing the instrumentation system and testing the performance of the system. System performance is tested through variations in the distance and angle of the objects. The measurement results show that the system can detect objects in front of the sensor up to a distance of 2.8m and an angle of for a distance of 1m. The measurement using different angles of objects was performed for objects on the left and right sides of the sensor. In addition, a warning alarm will be on when the distance of the object exceeds the allowed distance.

LOCAL GEOLOGY AND SITE CLASS ASSESSMENT BASED ON MICROTREMOR DATA IN NORTH LOMBOK

Lombok Island is an active seismic area in Indonesia potentially hit by an earthquake due to located between two earthquake generators from the south and the North. Several large earthquakes rocked Lombok, an earthquake with a magnitude of 6.4 on July 29, 2018, and 7.0 on August 5, 2018. This study aims to determine the characteristics of the local site effect based on the dominant frequency value ( ), soil amplification ( ), sediment layer thickness (d), , dominant period (T0), and seismic vulnerability index ( ) and to comprehend the soil class (site class) based on the thickness of the sediment layer (d), and in the North Lombok region. The data used is secondary data from microtremor signal recordings in North Lombok Regency in 2018. Data processing used Geopsy software, and microtremor data were analyzed using the HVSR method. From processing the HVSR data, the dominant frequency value about (0.8 - 18) Hz, amplification value (1.7 – 9.7), dominant period value (0.05 – 1.2) seconds, seismic vulnerability index value (0.4 – 71) , and the value of in the study area (20.05 – 287.04) m/s. Based on microtremor analysis, the local site effect indicates that alluvium rocks caused stronger earthquake vibrations and more damage. Whereas the Kalibabak and Lekopiko formations caused fewer earthquake vibrations and less wear. Based on the dominant period and , area study classify as Site Class IV class E and Site Class III class D Copyright © 2021 IPR. All rights reserved.

IDENTIFIKASI SIFAT FISIS KANDIDAT WAFER DARI LIMBAH TAHU SEBAGAI ALTERNATIF PAKAN TERNAK

Inovasi pembuatan pakan ternak dalam sediaan wafer perlu dilakukan untuk menjadi alternatif pakan saat musim kemarau. Limbah tahu merupakan salah satu bahan dasar yang dimanfaatkan sebagai bahan pembuatan wafer. Tujuan penelitian ini untuk mengidentifikasi perlakuan yang direkomendasikan dalam pembuatan kandidat wafer berdasarkan karakteristik fisis wafer. Kandidat wafer ditinjau berdasarkan warna, kadar air, densitas wafer, densitas partikel, dan porositas. Proses pembuatan wafer dilakukan dengan proses pemadatan dan pemanasan. Sebelum serbuk limbah tahu dicetak, dipastikan dahulu kadar air pada serbuk limbah tahu sesuai dengan stadar SNI 3148:2:200. Suhu pemanasan serbuk limbah tahu yang direkomendasikan menggunakan suhu 100oC. Karakteristik serbuk limbah tahu yang dihasilkan yaitu serbuk berwarna putih, kadar air sebesar 14,1% dengan nilai densitas partikel serbuk limbah tahu(𝜌sa ) 0,189g/cm3 serta porositas (𝜙sa ) 0,216%. Sedangkan untuk proses pencetakan wafer, suhu pemanasan yang direkomendasikan yaitu 70oC. Kandidat wafer yang diperoleh menghasilkan warna putih, tahan hingga 4 minggu, kadar air 7,19%, densitas partikel (𝜌p ) 0,254 g/cm3, densitas wafer 1,10 g/cm3 dan porositas 𝜙w sebesar 3,47±0,0118%.

PENGUKURAN LAJU ALIRAN UDARA DALAM PIPA SECARA SIMULTAN DENGAN TRANSDUSER GANDA ULTRASONIK

This paper aims to modification the transducer ultrasonic for measuring the distance to develop measure time of flight in the pipe with simultaneous method. To implement the application, we try to develop the microcontroller with one command transmitter and one command receiver in the same time, different from the conventional way, the transmitter and receiver work with consecutively. We try to reduce the delay time in two different transducers. In industrial, the symmetries profile must be ensured the profile always laminar. In this research, we try to use one path configuration. The result with the reference hot wire, we got the 27.76 percentage the difference of result. This is because the hot wire can measure the one path of flow in the one way of dot point.

PARTICLES SIZE AND LATTICE STRAIN EFFECT ON THE OPTICAL CONSTANTS OF Fe3O4 NANOPARTICLES

In the case of optical sensors such as the Surface Plasmon Resonance (SPR) sensor, the Fe3O4 nanoparticles play a role to boost the signal however they can increase the detection sensitivity of the biosensor. For this application, the optical properties of Fe3O4 nanoparticles need to be studied. The optical properties are described in terms of their optical constants. Therefore, this work was purposed to study the effect of the particle size and lattice strain on the optical constants of Fe3O4 nanoparticles. Samples were synthesized by using the coprecipitation technique. Two calcination temperatures, i.e., 150oC and 250oC for 4 hours were applied to the samples. Samples were characterized for their diffraction pattern and optical properties by using XRD and Specular UV-Vis Spectroscopy technique, consecutively. The particle size and lattice strain were estimated by using the Williamson-Hall (W-H) method. The effect of the particle size and their optical constants on the reflectance curve in the SPR sensor application was also performed toward a simulation by using Winspall 3.02 software. The results show that calcination temperature causes an increase in particle size and a decrease in lattice strain. The optical constants, such as absorbance (A), absorption coefficient (α), extinction coefficient (k), refractive index (n), dielectric constants (ε), optical conductivity (σ), and the Urbach energy (Eu) significantly depended on particles size and lattice strain. However, the particle size and optical constant were significantly influent the SPR angle in the reflectance curve of Fe3O4