Journal of Mathematical and Fundamental Sciences
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Assessing Resistance and Bioremediation Ability of Enterobacter sp. Strain Saw-1 on Molybdenum in Various Heavy Metals and Pesticides
Get PDFOne of the most economical approaches for removal of toxic compounds is bioremediation. In the long term, bioremediation is economic and feasible compared to other methods, such as physical or chemical methods. A bacterium that can efficiently reduce molybdenum blue was isolated from polluted soil. Biochemical analysis revealed the identity of the bacterium as Enterobacter sp. strain Saw-1. The growth parameters for optimal reduction of molybdenum to Mo-blue or molybdenum blue, a less toxic product, were determined around pH 6.0 to 6.5 and in the range of 30 to 37 ℃, respectively. Glucose was selected as preferred carbon source, followed by sucrose, maltose, l-rhamnose, cellobiose, melibiose, raffinose, d-mannose, lactose, glycerol, d-adonitol, d-mannitol, l-arabinose and mucate. Phosphate and molybdate were critically required at 5.0 mM and 10 mM, respectively. The scanning absorption spectrum acquired to detect the development of complex Mo-blue showed similarity to previously isolated Mo-reducing bacteria. In addition, the spectrum closely resembled the molybdenum blue from the phosphate determination method. Heavy metals, including mercury, copper (II) and silver (I), inhibited reduction. Moreover, the bacterium also showed capability of exploiting the pesticide coumaphos as an alternative carbon source for growth. As the bacterium proved its ability to detoxify organic and inorganic xenobiotics, the usefulness of this microorganism for bioremediation is highlighted
Implication of Negative Temperature in the Inner Horizon of Reissner-Nordström Black Hole
Get PDFThis paper reconsiders the properties of Hawking radiation in the inner horizon of a Reissner-Nordström black hole. Through the correlation between temperature and surface gravity, it is concluded that the temperature of the inner horizon is always negative and that of the outer horizon is always positive. Since negative temperature is hotter than any positive temperature, it is predicted that particle radiation from the inner horizon will move toward the outer horizon. However, unlike temperature, entropy in both horizons remains positive. Following the definition of negative temperature in the inner horizon, it is assured that the entropy of a black hole within a closed system can never decrease. By analyzing the conditions of an extremal black hole, the third law of black hole thermodynamics can be extended to multi-horizon black holes
Error Assumptions on Generalized STAR Model
Get PDFFor GSTAR models, the least squares estimation method is commonly used since errors are assumed be uncorrelated. However, this method is not appropriate when errors are correlated, either in time or spatially. For these cases, the generalized least squares (GLS) method can be applied. GLS is more powerful since it has an error parameter that can act as a controller of the model to produce an efficient estimator. In this study, R Software was used to estimate GSTAR parameters. The resulted model was applied to real data, i.e. the monthly tea production of five plantations in West Java, Indonesia. The best model for forecasting was the GSTAR(1;1) model with temporally correlated error assumption
Riesz Representation Theorem on Bilinear Spaces of Truncated Laurent Series
Get PDFIn this study a generalization of the Riesz representation theorem on non-degenerate bilinear spaces, particularly on spaces of truncated Laurent series, was developed. It was shown that any linear functional on a non-degenerate bilinear space is representable by a unique element of the space if and only if its kernel is closed. Moreover an explicit equivalent condition can be identiï¬ed for the closedness property of the kernel when the bilinear space is a space of truncated Laurent series
Thickness Effect on Fluctuation of Electron States in Thin Film and Implications for Lattice Constant Change Due to Size Reduction
Get PDFWe propose a model for predicting the fluctuation of electron states in thin films as a function of film thickness. The model is derived based on the assumption of the existence of potential barrier fluctuation on the film surface. Since the wave functions of electrons in the film are determined by the boundary conditions of the potential on the film surface, the potential fluctuation on the film surface implies fluctuation of the electron states in the film. The model was extended to predict the effect of size on the lattice constant of thin films or nanoparticles
Safe Dosage of Caprine CSN1S2 Protein from Fresh Local Goat Milk for Rats Evaluated by Acute and Sub-Chronic Toxicity Testing
Get PDFCaprine milk CSN1S2 protein contains bioactive peptides that have a specific function in regulating the metabolic homeostasis mechanism between different organs. However, the safe dosage of goat milk consumption has not been established previously. The aim of this study was to evaluate the safe dosage of caprine CSN1S2 protein from fresh local goat milk using acute and repeated doses (for 4 weeks) in oral toxicity studies on three month old normal Wistar rats. The CSN1S2 protein was isolated from fresh goat milk. This casein protein administered in a single oral gavage dose to 5 rat groups at a daily dose of 0, 500, 1000, 2000, 4000 mg/kg BW for acute and 28-day sub-chronic toxicity testing of rats of both sexes. The result showed no evident mortality or abnormal effects. Data analysis of body weight, water and food intake, blood biochemical parameters, clinical observation and organ weight revealed no significant differences between all groups for both sexes. The weights of some organs showed differences between groups, but these values were within the normal weight ranges. The conclusion is that caprine CSN1S2 from fresh milk is safe for food consumption because there was no indication of toxicity, no mortality, and no hematological and clinical chemistry changes
Quantitative Analysis of Color Combination from LED and Laser Light Sources Using Modified CIE 1931 Color Space Coordinates
Get PDFIn this study, a quantitative analysis based on the color space coordinates CIE 1931 to determine the color combination from three LEDs (light emitting diode) sources and three laser sources separately, has been investigated. The light sources used in this research were three LEDs that emit blue light, green and red colors, and three laser sources that also emit blue light, green and red colors. Result of color combination from LEDs and laser light sources were detected using a spectrophotometer. The result of the light spectra were then analyzed using a set of color matching function that has been modified specially for the spectrophotometer used. This research produced quantitative analysis for 26 color combinations of LED light sources and 7 color combinations of laser light sources. The results of colors combination were ranging from blue, cyan, yellow, orange, red to purple. Further development is still required to obtain reliable quantitative analysis results
