Jurnal ILMU DASAR
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A Prototype Fabrication of Sensitive Porous Silicon NOx (x=1,2) Gas Sensor
Get PDFA prototype of (porous silicon (PS) based) NO(x=1.2) gas sensor based on porous silicon (PS) (operated at room temperature) has been fabricated. The sensor could be operated at room temperature. The (PS) basic material for the material sensor ( i.e. PS) was fabricated in the previous research by varying (parameter of the HF concentrations) concentrations of HF (what is HF?) and (the anodization time) time of anodizations. Its structure, as well as its optic, has been characterized. In this research, we did electrical characterization of PS to find its conductivity. The conductivity of PS is important because PS, as a sensor, utilizes the changes of conductivity when it is passed by NO(x=1.2). (The influence of these parameters on I-V characteristics of the PS and on the sensor performances has been studied in detail) The changes of electrical current because of the varying NO concentrations with time were measured using a current measuring system, then plotted. The result (shows) showed that the sensor could detect NO (and NO) gasses ranging from 16 ppb to 200 ppb and NO gas ranging from 12 ppb to 200 ppb, respectively at room temperature (28C) and at adjusted currents ranging from 20 to 800 μA. The result also showed that the sensor was not completely reversible for NO. xxx22oxÂ
Forecasting Interest Rate of Bank Indonesia Certificate Based on Multivariate Fuzzy Time Series Data
Get PDFThe aim of this research is to establish a model for forecasting interest rate of Bank Indonesia Certificate (BIC)based on six-factors one-order fuzzy time series data where the main factor is interest rate of BIC and thesecondary factors are interest rate of deposit, exchange rate, deposit supply, inflation rate and money supply.Steps to forecasting interest rate of BIC are based on Wang’s method. The result of this research is thatprediction of interest rate of BIC using multivariate fuzzy time series model has higher accuracy than that usingneural network method with average forecasting error 3.1256% and MSE value = 0.2699
CPO Bleaching Optimization Using Activated Charcoal And Bentonite
Get PDFResearch of Crude Palm Oil (CPO) bleaching optimization using activated charcoal and bentonite on biodiesel synthesize had been done. The aim of this research is to find optimum condition of bleaching process, by making variation of activated charcoal and bentonite ratio as adsorbent (1:0, 1:10, 1:15, 1:20 and 0:1), temperature (non heated, 40-50oC, 60-70oC, 80-90oC and 100-110oC) and time (1; 1,5; 2; 2,5 and 3 hours). The results of this research will be used as optimal conditions for synthesizing biodiesel. Optimum condition was determined by observing the lowest absorbent which was measured by using spectronic-20 on 445 nm. Results showed that optimum activated charcoal and bentonite adsorbent ratio was 0:1, optimum temperature was 100- 110oC and optimum time was 3 hours
Predicting Interval of Product Reliability With Bootsrap Percentile Method
Get PDFIn this article, two methods are proposed to give the interval estimation for reliability function from a product. Reliability function is a probability of an individual (product) surviving till time t. Some resecearchers usually use traditional method to construct interval estimation. This interval needs an assumption that sample is exponentially distributed. This research applied another method, namely Bootstrap percentile. Bootstrap method is more potential in constructing interval estimation for reliability function from a product
Impurity Free Vacancy Disordering (IFVD) of InxGa1-xAs/InP Quantum Well Structures for Monolithic Integration of Different Optoelectronic Devices
Get PDFImpurity free vacancy disordering (IFVD) technique has been used to study the atomic intermixing of InxGa1-xAs/InP quantum well structures using a SiO2 and a TiO2 dielectric layer. Three different indium composition in InGaAs QWs were investigated, lattice-matched (LM), compressively-strained (CS) and tensile-strained (TS). Based on Photoluminescence results, the atomic intermixing between the quantum well and the barrier regions enhanced when the samples were coated with SiO2 layers. Although TiO2 layers were able to suppress the intermixing in InGaAs/InP system, the suppression was not significant compared to the AlGaAs/GaAs system. Based on a fitting procedure that was deconvoluted from the photoluminescence spectra including theoretical modeling, the electron-heavy hole and electron-light hole transitions were identified and a ratio of the group V to the group III diffusion coefficients (k) were obtained. The k ratio of the InGaAs/InP samples capped with SiO2 is relatively larger than of samples capped with TiO2 layers.Â
Laser Induced Thin Film Production (LITFP) Using Nitrogen (N2) Laser Deposition
Get PDFLaser induced thin film production (LITFP) technique was employed for making Lead (Pb) thin film by nitrogen laser ablation in miniature scale. The energy of nitrogen laser operated at 12.5 kv, 90 torr was 3.5 mJ with 5 ns pulse duration, thus producing peak power at around 0.7 MW. Pb plasma of 1 cm diameter was generated in each laser bombardment, producing thin film above the glass substrate. The thin film characteristics were measured by the thickness and surface morphology using scanning electron microscope (SEM). It was proved that there was a linear relationship between the number of laser shots and film thickness
Cross-linked Chitosan Synthesis Using Glutaraldehyde and Functional Group Identification as well as Its Deacetylation Degree
Get PDFCross-linked chitosan with 78,12% deacetylation degree, synthesed from chitosan bead with 135,982% swelling degree were conducted. Chitosan bead has prepared from chitosan that was dissolved with watery acetic acid and coagulated with sodium hydroxide. Chitosan with 79,6% deacetylation degree was prepared from chitin that was submitted to a deacetylation reaction. Chitin were applied, isolated from giant tiger shrimp that was submitted to a demineral and deproteination reaction. Functional group of the cross-linked chitosan with glutaraldehyde were investigated by the Infra Red spectroscopy and deacetylation degree were investigated by the base line methods. Chitin, chitosan and chitosan bead have the same structure. The difference between chitin and chitosan was the deacetylation degree and chitosan bead in the physical shape. The deacetylation degree and swelling degree of chitosan bead was decreased by cross-linking process
Effect of Hyperglikemic Conditions on Ovarian Structure and Estrous Cycle of Mice (Mus musculus L)
Get PDFStreptozotocin cause hyperglycemic condition in mice. The objective of this study was to determine whether the hyperglycemic conditioned by streptozotocin (STZ) has an impact at folicullar atretic and estrous cycle prolonged. Mice were injected by STZ until hyperglycemic condition was reached. The vaginal smear was recorded daily for twice estrous cycle. Mice were sacrificed soon after the last vaginal smear observation. The ovary was removed, prepared by parafin method and stained by hematoxylin-eosin.The result showed that hyperglycemic causes increasing the number of atretic follicles, decreasing the number of corpus luteum and prolonged of estrous cycle
Interval Estimation for Quantile on Two Parameters Exponential Distribution Under Multiple Type-II Censoring on Complex Case with Bootstrap Percentile
Get PDFIn this article, two methods are proposed to give the interval estimation for quantile on two parameters exponential distribution under multiply type II censoring. The interval estimation for quantile can be constructed the estimated parameters. Those researchers have use approximate maximum likelihood estimator to construct interval estimation for two parameters exponential distribution under multiply type II censoring. All of these method need an assumption that sample is exponentially distributed. We will use another method, known as the bootstrap percentile. This method gives shorter interval than the traditional method and this method does not need an assumption that the sample is distributed exponentially
Consistency and Asymptotic Normality of Maximum Likelihood Estimator in MARS Binary Response Model
Get PDFA good estimator has to fulfill some propertries such as unbiased, efficient and consistent. This research aims to study consistency and asymptotic normality of maximum likelihood estimator in MARS binary response model of Friedman, for predicting the continue response variable, at  predictor variables,  with linear combination of spline truncated