Jurnal ILMU DASAR
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Characterisation of Arsenic Distribution in the Contaminated Sediments Using Principal Component Analysis based on The Four-Step Extraction Protocol
Get PDFThe goal of this work was to characterize the distribution of arsenic in the contaminated sediments using principal component analysis to interpret data generated by a four-step extraction protocol, an operationally defined fractionation procedure used to study the availability and mobility of trace metals available in environmental solid samples. Sediment cores collected from contaminated site of Port Kembla Harbour, Australia were sliced into 2-cm thin layers. Each layer was sieved into three different grain sizes (<63μm, >63 μm and >250 μm) under inert N2 atmosphere. Redox potential, pH, dissolved As in the interstitial water, exchangeable As, AVS-As, reducible As, and residual As data provided some reliable information concerning the characteristics of As distribution in the contaminated sediments. Principal component analysis indicated As in the fine grain fraction and redox potential developed in the sediment contributed more significantly in controlling the concentration of dissolved As in the sediment interstitial water. It appeared that precipitation-dissolution reaction of As taken place in the sediment involved the fine grain solid phase and occurred actively at redox transition zone at which it changed significantly and the concentrations of dissolved As were high
Aplication of Caliberation Model using Discrete Wavelet Transformation – Partial Least Square for Giengerol Data
Get PDFThe determination of concentration of gingerol compound is usually carried out through a long and expensive process using HPLC instrument. The alternative method to predict such concentration can be done using a multivariate calibration model. Since the numbers of samples (n) are less than the number of variables (p) and between the independent variables are correlated, the development of model using conventional regression is no longer valid. The combination of Discrete Wavelet Transformation (DWT) and Partial Least Square has been adopted in this research to predict concentration of gingerol and it showed a promising result.Â
Estimation of Plankton Population Using Ensemble Kalman Filter
Get PDFThe objective of this paper is to simulate how the Ensemble Kalman Filter (EnKF) works to estimate plankton in the one-dimensional three components ecosystem model. The analysis has been done separately between nutrition component and plankton component. The simulation demonstrated that the EnKF with 100 ensembles has as good estimation as with 1000 ensembles. It will also be ilustrated that the increasing of ensemble size in EnKF can decrease the norm of error covariance of plankton component
The S Robust Estimator in Seemingly unrelated Regression Model
Get PDFRegression parameter estimation is mainly used to describe the effect of dependent variable to the response variable. On development of it, parameter estimation is also used to case of multivariate regression. Seemingly Unrelated Regression model is one of regression multivariate cases which has especially assumption, i.e., correlation between errors on the multivariate regression. Robust S is one of robust estimation methods. This estimation can be resistant in presence of outlier in the data. In this research, we studied about parameter estimation for Seemingly Unrelated Regression model using robust S. We applied the model obtained to General Electric and Westinghouse data from 1935 to 195
Synthesis of a Sunscreen Compound n-Octyl Para-Menthoxy Cinnamat using Ethyl Para-Methoxy Cinnamat Isolated from Kencur Tuber (Kaemferia galanga L.) as Raw Material
Get PDFA sunscreen compound namely n-octyl para-methoxy cinnamat (OPMC) had been synthesized from the ethyl para-methoxy cinnamat (EPMC) isolated from the kencur tuber (Kaemferia galanga L.) as the raw material. The convertion of EPMC to OPMC was conducted by hydrolysis reaction of EPMC using the alcoholic KOH solution catalyst to yield para-methoxy cinnamat acid (PMCA). Futhermore, the esterification reaction of PMCA and n-octanol, using the concentrated sulfuric acid catalyst produced OPMC as a colorless needle crystal with rendemen 53.98%. The molecular structure of OPMC was identified by spectroscopic methods including UV, IR, 1H-NMR, and EIMS
Computer Simulation of Pouring Grains Using Stick-Slip Model
Get PDFWe applied the Stick-Slip model to simulate pouring grains processes via Granular Dynamics Simulation. The dynamics mechanism and the structure formation of the 2D and 3D systems are investigated. The results show that the shape of the generated piles in the 2D and 3D systems are similar when observed superficially, but the detailed structure and the dynamic behaviour leading to that structure are very different
Effect of Reaction Temperature and the CPO/Metanol Ratio on the Product Characteristics in the Biodiesel Production Using Diethyl Eter as Co-Solvent
Get PDFIn this research Crude Palm Oil (CPO) and methanol were reacted by applying 5 % basic catalyst (KOH) and adding diethyl ether as co-solvent to produce methyl ester (biodiesel). Co-solvent was added in order to form one-phase reaction mixture, and then higher reaction rate was expected compare with two-phase system. Reaction was carried out batch wise in 1 litre glass reactor stirred continuously at 300 rpm. The objective of this research is to obtain the characteristic of biodiesel product. The advantage using this methode was showed by several characteristics of the biodiesel product. The density and viscosity had achieved the commercial biodiesel standard, this biodiesel product has higher flash point of the product compared with solar, which means lower risk factor during storage. The very low sulfur content and the pour point of product that was layed below the maximum allowable limit, are environmentally favorable.Â
Alternative Model of Cellular Immune Reactions in Insect
Get PDFThe cellular immune reactions involve mainly the insect blood cells or hemocytes and consist of adhesive reactions of hemocytes against microbes or parasites. Among these various hemocytes, the granulocytes and plasmatocytes are thought to be the most important hemocytes involved in insect cellular defense. According to the number and size of the foreign invaders in the insect hemocoel, three major cellular defense reactions can be classified: Phagocytosis, encapsulation and nodule formation. Many of the initial interactions leading to coagulation and phagocytosis reactions in insects are sugar-lectin binding reactions, involving homeostasis- and defense-related receptors, such as scavenger receptors and mucin-like immune receptors. However, the mechanism that cause the formation of endocytotic vesicles are not known. The major aims of this study are 1) To test the induction of cell-spreading and macropinocytosis, 2) To investigate the role of lectins in coagulation reaction. The observations suggest that in the presence of lectins hemocytes can either form coagulation products, such as globules, or perform cellular functions, such as adhesion and macropinocytosis. Since coagulation and cell activities are quite disparate processes, the balance between the two types of reactions is quite relevant for the overall outcome. In cell-free hemolymph (plasma) only coagulation reactions occur in the presence of externally added GalNAc-specific lectins
Are Bacteria The Main Producers of Hydrolytic Enzymes in Aquatic Environment
Get PDFBacteria play an important role in the decomposition of organic matter, which is a key process in aquatic microbial food webs as well as its application in water bioremediation processes. DOM (Dissolved Organic Matter) is the major fraction of organic matter in most aquatic environments. Most of DOM is present as high molecular weight compounds that cannot be taken up by bacteria directly. Therefore, they must be hydrolysed enzymatically to be transported across microbial cell membranes. Molecular fluorosensors have been used as artificial substrates to study hydrolytic enzymes in situ. The present study wants to investigate the following hypothesis i.e. bacteria are the main producers of hydrolytic enzyme in aquatic systems. There were not any significant correlations between bacteria and the investigated hydrolases (esterase, peptidase, and β-glucosidase) in the meso- to eutrophic aquatic systems near Rostock city – North East Germany, although a wide range of bacterial abundances were covered. Enzyme saturations were not detected in all samples which may be explained by a high KM indicating a low affinity of enzymes (1) and or the contribution of many enzymes with different kinetics to the respective substrate degradation (2). There is also increasing evidence that bacteria may not be the sole or dominant source of esterases, peptidases and β-glucosidases in aquatic ecosystems. Invertebrate, fungi and other eukaryotes (diatoms, protozoa etc.) must be considered as possible and even important producers of hydrolytic enzymes. Several other factors may influence the correlations of bacteria to hydrolytic enzyme activities, i.e. variations in the species composition (1), a wide ranged variability of hydrolytic activities influenced directly by other substrates (low enzyme affinity), element availability (N and P), temperature and other abiotic factors (2), the existence and persistence of enzymes caused by other (passive) processes (e.g. cell lysis) (3)
Coal Ash Characteristic from Bukit Asam as Raw Material for Ceramics Production
Get PDFThis study was carried out to characterize coal ash obtained from Bukit Asam, Tarahan Lampung, after the samples were sintered at various temperatures ranging from 900ï‚°C - 1300ï‚°C. The characteristics of the investigated samples included density, porosity, hardness, structure and microstructure. The results indicated that porosity decreased with increasing sintering temperature, while density and hardness increased with increasing temperature. The x-ray diffraction (XRD) study revealed that the main crystalline phase was silicon dioxide (SiO2), with the minor constituents of CaSiO2, MgSiO3, FeSiO4 and Ca12Al14O33. SEM investigations clearly demonstrated the presence of a fine crystallised phase dispersed in the microstructure