Spektra: Jurnal Fisika dan Aplikasinya
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MULTI-CHANNEL FRY COUNTER DESIGN USING OPTOCOUPLER SENSOR
Get PDFThis paper describes a design of a fry counter intended to be used by consumption fish farmer. Along this time, almost all the fry counting processes are counted by manual, which is done by human. It is requiring much energy and needs high concentration; thus, can cause a high mental and emotional exhaustion for the fry counting worker. Besides that, the human capability and capacity for counting the are limited to a low number. A fry counter design in this study utilizes a multi-channel optocoupler sensor to increase the counting capacity. The multi-channel fry counter counting system is developed as a solution to a limited capacity of available fry counter. This design uses an input signal extender system for the sensor. The design is based on the interrupt combiner to accommodate multi-channel sensor used. Besides, the transmitter beam's angle is adjusted to deal with the deflection due to water surface. From the experiment, multi-channel sensor can be implemented and high accuracy level could be obtained on the counting and channel number detection, therefore, this design can be implemented and could help farmers to increase the production capacity of consuming fish
FRUIT SWEETNESS CHARACTERIZATION USING IMPEDANCE SPECTROSCOPY METHOD
Get PDFThe processing of agricultural products requires technology implementation to increase its production. One way of this technology implementation to increase the production is fruit sweetness measurement, which can be used as a sorting tool of fruit products. The sorting process using this tool can be done with easier way compare than the manual and destructive test. The fruit sweetness is composed of a mixture of sweet molecules fructose, glucose, and sucrose. The measurements of these molecules are usually done with four-point probe and use dc current. In this study, a fruit sweetness characterization using impedance spectroscopy method has been developed and realized, which uses an ac current. By using this method, fruit sweetness level can be characterized based on the impedance measurement on the flesh of a test fruit based on its dielectric properties. The obtained characterization results show that the fruit sweetness level can be measured by the impedance measurement. The obtained impedance is proportional to the concentration of the sweet molecule glucose. This method can characterize the fruit sweetness well and agrees with the calibration result. Therefore, this method can be used to increase agricultural products
BURIED WAVEGUIDE POLYMETHYLMETHACRYLATE MODELING FOR REFRACTIVE INDEX SENSOR APPLICATION USING FINITE ELEMENT METHOD
Get PDFThe purpose of this study is to obtain the optimum buried waveguide structure through modeling for refractive index sensor applications. The waveguide cladding material used as Polymethylmethacrylate (PMMA). The core cross-section size was 1 × 1 mm2. The simulation was carried out at a wavelength of 650 nm using the Finite Element Method (FEM). The parameter of the buried waveguide optimized in this model was the core refractive index and the thickness of the upper cladding to obtain a high propagation constant and good sensitivity to refractive index. Modeling was done for various core refractive index values varied in the range of 1.52 to 1.59, which are the refractive index of various types of polymers. To optimize the sensitivity, the thickness of the upper cladding was varied between 0.125mm to 0.5mm. Besides, a simulation was also carried out for a waveguide without an upper cladding. The results show that the optimum waveguide is a waveguide without upper cladding using polyester as core material with a refractive index value of 1.57 and a sensitivity of 4.9 × 10-10rad /m. RIU
FLUIDIZATION OF A BED OF SOLID PARTICLES IN A TWO DIMENSIONAL VERTICAL BOX
Get PDFSimulation of fluidization of a bed of solid particles in a two-dimensional box is performed using molecular dynamics methods by assuming that superposition of buoyant, gravitational, viscous, collision force will make the particle to move in two dimensions. Two different fluid type is used in this simulation, i.e., gas and liquid fluid. By increasing the fluid velocity from small to high, then minimum fluidization condition reached. As a result, fluidization of alumina particle with liquid fluid has a minimum fluidization velocity lower than gas fluid
HEATING AND QUENCHING PROCEDURE ON THE MAKING OF TRADITIONAL BLACKSMITH STEEL WITH HIGH QUALITY
Get PDFBlacksmith is a people's business that has been going on for a long time in Indonesia. Based on the experience that has been obtained from time to time and hereditary, the blacksmith industry has been done by the community to meet the needs of agricultural and household utensils. However, observe to this people's business, now it decreases with various causal factors, such as the ease of imported goods on the market with lower prices. Many creative efforts need to be carried out so that these people's businesses remain and increasingly develop, among others by improving the quality of the process of a blacksmith so that their products are quite competitive. This article describes the results of the research in the laboratory regarding the physical processes of heating and quenching under blacksmith, which the results have been applied to community service activities at the Suger Kidul villages in Jember Regency. The study aimed to find the most appropriate procedure for steel tool manufacturing processes so that the blacksmith products have high quality as high hardness. The physical process for blacksmith process is heating and quenching. This study analyzes the proper heat (temperature), proper processing time, and proper media for heating and quenching to produce good harness quality of the product
THE EFFECT OF POLY (ETHYLENE GLYCOL) ON THE PHOTOLUMINESCENCE PROPERTIES OF CARBON DOTS FROM CASSAVA PEELS SYNTHESIZED BY HYDROTHERMAL METHODS
Get PDFCarbon dots (C-dots) have been successfully synthesized from cassava peels using the hydrothermal method. The C-dots are further passivated using poly (ethylene glycol) (PEG) with a variation of the volume of 0.5 ml, 1.0 ml, and 1.5 ml. The properties of photoluminescence C-dots before and after PEG were characterized using photoluminescence (PL) and time-resolved photoluminescence (TRPL) spectrophotometers. PEG succeeded in influencing PL C-dots properties, such as peak wavelength, PL intensity, and electron time decay. The addition of 0.5 ml of PEG to C-dots is the optimum condition and best with the peak wavelength, the PL intensity and, time decay electron is 507.52 nm, 5302 a.u, and 3.794031133 ns, respectively