Spektra: Jurnal Fisika dan Aplikasinya
Not a member yet
254 research outputs found
Sort by
MEASURING INSTRUMENT FOR REFILLED DRINKING WATER USING A TDS SENSOR
Get PDFWater is an essential need for humans and consumed as drinking water after fulfilling the health requirement in the Republic of Indonesia Minister of Health Regulation No.492/Menkes/Per/IV/2010. Due to the increasing demand, there are currently many refilled drinking water stores as an economical and practical alternative way to people. However, their safety still needs to be tested in the laboratory. This condition is impractical so that it needs a portable measuring instrument especially based on the TDS sensor that can measure the total dissolved solids (TDS) and electrical conductivity (EC) at once, which determines the taste and safety of the water. TDS sensor calibration at 80.5 to 966 ppm shows a 93.4% accuracy; 99.8% precision and 1.3 ppm hysteresis. In comparison, EC calibration at 161 to 1932 microsiemens/cm produces an average of 82.3% accuracy, 97.1% precision, and 1.0 microsiemens/cm hysteresis. This prototype is then employed to measure the water sample and determine its safety to consume and observed a decreasing trend of TDS and EC (194.1 ppm and 388.2 microsiemens/cm) as compared to the water spring sample (20.2 ppm and 402.3 microsiemens/cm). The prototype also has a Bluetooth module that enabling the remote observation on a cell phone without the presence of a telephone network
UNCERTAINTY ANALYSIS OF LABORATORY MEASUREMENT OF AIRBORNE SOUND INSULATION
Get PDFThe evaluation and analysis of the uncertainty of laboratory measurement of airborne sound insulation have been carried out by Research Group for Acoustics and Vibration – National Standardization Agency of Indonesia (BSN). The aims of this work are to evaluate and analyze the uncertainty measurement of airborne sound insulation by pressure method, where it is focused only for the determination of sound transmission loss (STL) as a major product of this measurement according to ASTM, and guide to the expressions of Uncertainty in Measurement (GUM) provided by JCGM. The supplied parameter of uncertainty budgets includes measurement of sound pressure level (SPL) in a source room (L1), and measurement of some parameters in a receiver room such as SPL (L2), reverberation time (RT60), background noise (B), test opening area (S), and volume of receiver room (V). From the result of the case study, the source of uncertainty that has a top contribution for obtaining expanded uncertainty is considered as the repeated measurement of the measured parameter such as L1, L2, and RT60 at the frequency range 250 Hz – 315 Hz. Meanwhile, the standard uncertainty that provided by the calibration certificate also contributes to the final result, where it is supplied by an acoustic calibrator and sound analyzer, respectively. Furthermore, the sources obtained from the readability parameter has a slight effect on this whole result. Therefore, the maximum and minimum value of expanded uncertainty is determined that their values are 0.70 dB and 0.43 dB for the frequency of 315 Hz and 1600 Hz, respectively
THE INFLUENCE OF SURFACTANT AND PROTECTIVE COLLOID ON POLYVINYL ACETATE EMULSION SYNTHESIZED BY EMULSION POLYMERIZATION TECHNIQUE
Get PDFA series of experiments have been carried out and reported. This report describes the stages of the polymerization reaction during emulsion Polyvinyl Acetate (PVAc) synthesis. PVAc was synthesized from the Vinyl Acetate Monomer (VAM) with Ammonium Peroxydisulphate (APS) as an inorganic thermal initiator in the aqueous media under reaction temperature was keep at 65 until 75oCs by agitation speed was 300 rpm respectively during 4 hours of reaction time. The protective colloid agents and several types of surfactants were added to improve the obtained emulsion PVAc performance. The polymerization reaction was carried out without the addition of a protective colloid agent. The surfactants were produced the emulsion PVAc with the properties of solid content 0.89%, density 1.02 g/ml, viscosity 0.0033 Poise, pH 2.8, conductivity 12 ms, respectively. While the polymerization reaction involved protective colloid agents by using Polyvinyl Alcohol (PVOH) was obtained properties of emulsion PVAc with Solid Content 4.36%, density 1.17 g/ml, viscosity 0.0216 Poise, pH 2.8, and conductivity 10 ms respectively. The same thing was shown when the surfactant was present in the polymerization reaction. The emulsion PVAc was synthesized with nonionic surfactant has solid content 8.20%, density 1.17 g/ml, viscosity 0.0099 Poise, pH 2.8, and conductivity 7 ms, the result is better rather than synthesized with anionic surfactant has solid content 2.65%, density 1.13 g/ml, viscosity 0.0068 Poise, pH 2.8, and conductivity 11 ms. According to the preliminary observations obtained, emulsion PVAc’s appearance is better when the protective colloid agents and the surfactant is present rather than without additional those substances. The physical properties of emulsion were depended on the addition of protective colloid agents and surfactants. In addition, the complete reaction indicated by solid content value was obtained from emulsion when the additional substances were present. All the testing parameters were observed using Viscometer Ostwald, Pycnometer, pH Meter, FTIR Spectrophotometer, Conductometer, and another supporting testing to explain the polymerization reaction stage of synthesis emulsion PVAc. 
SYNTHESIS AND CHARACTERIZATION OF STRUCTURAL NANOCOMPOSITE TITANIUM DIOXIDE COPPER-DOPED USING THE IMPREGNATION METHOD
Get PDFNanocomposite Titanium Dioxide (TiO2) doped Copper (Cu), Cu-TiO2 is synthesized by the impregnation method. This study aims to determine the effect of adding Cu to the TiO2 structure. The 1, 3, and 5 Cu with% TiO2 dissolved in 50 ml of deionized water, and 3 grams of TiO2 added. The compound is then stirred for 2 hours at 90oC and dried in an oven at 110oC for 30 minutes. Drying samples were calcined at 500oC for 3 hours. Cu-TiO2 nanocomposites were characterized by XRD, SEM-EDX Mapping, and FTIR. The XRD analysis results show that Cu-TiO2 nanocomposite has a high level of crystallinity and has an anatase phase structure. The size of TiO2 crystals decreased with Cu doping and increased from 49.66 nm to 49.68 nm, with an increase in the composition of the doping mass of Cu. The SEM-EDX Mapping results show that all samples tend to clot, and Cu dopants evenly distributed on the surface of TiO2. FTIR analysis explained the presence of hydroxyl ions in the sample marked with the appearance of the absorption peak at 1658.78 cm-1 associated with OH bending of Ti-OH
SURFACE MORPHOLOGY OF SPUTTERED TITANIUM-ALUMINUM-NITRIDE COATINGS
Get PDFA study on the surface morphology of sputtered TiAlN coatings is presented. The coatings were deposited by DC magnetron sputtering on tungsten carbide insert tools. The surface morphology was characterized by using Atomic Force Microscopy (AFM), and the surface roughness was indicated by RMS roughness value. It was observed that the TiAlN coating surface morphology was rough as the negative substrate bias and nitrogen flow rate are increased. The evolution of the sputtered TiAlN coatings surface morphology was due to the competition between particle diffusion and re-scattering effect during the sputtering process. At high negative substrate bias and nitrogen flow rate, the re-scattering effect was prominent, leading to the high roughness of the sputtered TiAlN coating surface.  
ANALYSIS OF A PEAK GROUND ACCELERATION VALUE AND EARTHQUAKE INTENSITY USING DONOVAN METHOD IN BANTEN PROVINCE
Get PDFAnalysis of a peak ground acceleration value and earthquake intensity in Banten Province has been carried out using historical earthquake data from 2008 to 2018. This research aims to describe a prone area of the earthquake. The specification of data was a magnitude > 5 SR and the depth 0-70 km. The Donovan method was used to analyze peak ground acceleration value and the earthquake’s intensity. According to the data obtained, 31 earthquake points with a maximum earthquake strength occurred on October 16, 2019, with a depth of 10 km and a magnitude of 6.48 SR. This earthquake was located in Ujung Kulon with coordinates -6.81 LS and 105.113 BT. Based on data analysis result was obtained a peak ground acceleration value and the intensity of earthquake maximum in The Pandeglang Regency with a peak ground acceleration value was 211.56 cm/s2, and intensity of scale VIII and a large risk level of three. While a peak ground acceleration minimum is located in the South Tangerang City was 62.82 cm/s2 with a scale of intensity VII and a moderate risk level
COMPARISON STUDY OF VERTICAL CYLINDER TANK DIAMETER MEASUREMENT BETWEEN STRAPPING AND OPTICAL METHOD
Get PDFVertical Cylinder Tank is used as a storage area or as a measuring tool. Liquids are used in the form of Fuel oil, Liquid Natural Gas, vegetable liquids, and other chemical liquids. The tank calibration results are in the form of a volume per height table that is used as a reference by Automatic Tank Gauging. There are two tank calibration methods, namely: the strapping method and the optical method. The process of measuring the inside or outside diameter of the tank becomes very important in the tank calibration process—the measurement of tank diameter by the strapping method using steel meters manually. At the same time, the optical method uses theodolite or total station. For tank diameters ≤ 5 m, the strapping method has smaller diameter measurement results with a difference of 0.7% compared to the optical method. In further research, a prototype can be developed that can accelerate the calibration process using the strapping method (for example, a vertical track measuring robot) or a low-cost prototype theodolit
THE SYNTHESIS AND CHARACTERIZATION OF ZINC OXIDE THIN FILM DOPING SELENIUM
Get PDFThe selenium-doped ZnO nanomaterial has successfully grown the surface of FTO (Fluorine Tin Oxide) using a seed-mediated hydrothermal method at a temperature of 90°C for 5 hours. In this research, the doping selenium by variation the volume of selenium solution at 0 mL, 0.025 mL dan 0.2 mL. This is an impact on the optical properties and morphology of ZnO nanorods. The samples were characterized using UV-Vis spectroscopy, X-Ray Diffraction and Field Emission Scanning Electron Microscopy (FESEM). The UV-Vis spectra showed that strong absorption occurs in the wavelength range of 300-380 nm. The 0.025 mL Se doped ZnO was the highest absorption compared to other samples. The XRD pattern exhibited five peaks at an angle of 2θ: 31.70°; 34.4°; 36.2°; and 47.5°. representing the orientation of the crystal planes (100), (002), (101), and (102) of hexagonal lattice. The FESEM images showed that Se doped ZnO with hexagonal face shape. The 0.2 mL Se doped ZnO was the most uniform compared to other samples