Journal of Mathematical and Fundamental Sciences
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Estimation of S-wave Velocity Structures by Using Microtremor Array Measurements for Subsurface Modeling in Jakarta
Get PDFJakarta is located on a thick sedimentary layer that potentially has a very high seismic wave amplification. However, the available information concerning the subsurface model and bedrock depth is insufficient for a seismic hazard analysis. In this study, a microtremor array method was applied to estimate the geometry and S-wave velocity of the sedimentary layer. The spatial autocorrelation (SPAC) method was applied to estimate the dispersion curve, while the S-wave velocity was estimated using a genetic algorithm approach. The analysis of the 1D and 2D S-wave velocity profiles shows that along a north-south line, the sedimentary layer is thicker towards the north. It has a positive correlation with a geological cross section derived from a borehole down to a depth of about 300 m. The SPT data from the BMKG site were used to verify the 1D S-wave velocity profile. They show a good agreement. The microtremor analysis reached the engineering bedrock in a range from 359 to 608 m as depicted by a cross section in the north-south direction. The site class was also estimated at each site, based on the average S-wave velocity until 30 m depth. The sites UI to ISTN belong to class D (medium soil), while BMKG and ANCL belong to class E (soft soil)
Path Independence in Adiabatic Quantum Computing for Hadamard Gate
Get PDFThe computation time in adiabatic quantum computing (AQC) is determined by the time limit of the adiabatic evolution, which in turn depends on the evolution path. In this research we have used the variational method to find an optimized path. For the simplest case involving a single qubit and for the most general path involving one or more independent interpolating functions, the result is path independent. This result does not change when there is an extra Hamiltonian term. We have also applied these two scenarios in AQC to a Hadamard gate. Adding an extra Hamiltonian gives a non-trivial result compared to the normal AQC, however it does not result in a speed-up. Moreover, we show that in these two scenarios we can choose an arbitrary path provided that it satisfies the boundary conditions
Full Tensor Gradient of Simulated Gravity Data for Prospect Scale Delineation
Get PDFGravity gradiometry measurement allows imaging of anomalous sources in more detail than conventional gravity data. The availability of this new technique is limited to airborne gravity surveys using very specific instrumentation. In principle, the gravity gradients can be calculated from the vertical component of the gravity commonly measured in a ground-based gravity survey. We present a calculation of the full tensor gradient (FTG) of the gravity employing the Fourier transformation. The calculation was applied to synthetic data associated with a simple block model and also with a more realistic model. The latter corresponds to a 3D model in which a thin coal layer is embedded in a sedimentary environment. Our results show the utility of the FTG of the gravity for prospect scale delineation
Boolean Algebra of C-Algebras
Get PDFA C- algebra is the algebraic form of the 3-valued conditional logic, which was introduced by F. Guzman and C.C. Squier in 1990. In this paper, some equivalent conditions for a C- algebra to become a boolean algebra in terms of congruences are given. It is proved that the set of all central elements B(A) is isomorphic to the Boolean algebra S(A) B of all C-algebras Sa, where a  B(A). It is also proved that B(A) is isomorphic to the Boolean algebra R(A) B of all C-algebras Aa, where a B(A)
Dynamics of Cocoa Bean Pulp Degradation during Cocoa Bean Fermentation: Effects of Yeast Starter Culture Addition
Get PDFFermentation is a crucial step in the post-harvest processing of cocoa beans. This process comprises mixed culture microbial activities on the cocoa bean pulp, producing metabolites that act as important precursors for cocoa flavour development. Variations in the microbial population dynamics during the fermentation process may induce changes in the overall process. Thus, the introduction of a specific microbial starter culture may improve the quality of the fermentation. This article discusses the effects ofthe addition of Saccharomyces cerevisae var. Chevalieri starter culture on cocoa bean fermentation. The dynamics in the yeast concentration, sugary pulp compounds and metabolic products were measured during fermentation. The alterations in the dynamic metabolite profile were significant, although only a slight difference was observed in the yeast population. A higher fermentation index was measured for the cocoa bean fermentation with yeast starter culture, 1.13 compared to 0.84. In conclusion, this method can potentially be applied to shorten the cocoa bean fermentation time
A Note on Prediction with Misspecified Models
Get PDFSuppose that a time series model is fitted. It is likely that the fitted model is not the true model. In other words, the model has been misspecified. In this paper, we consider the prediction interval problem in the case of a misspecified first-order autoregressive or AR(1) model. We have calculated the coverage probability of an upper one-step-ahead prediction interval for both properly specified and misspecified models through Monte Carlo simulation. It was found that dealing with prediction interval for misspecified model is complicated: the distribution of a future observation conditional on the last observation and the parameter estimator is not identical to the distribution of this future observation conditional on the last observation alone
Properties of Polymer Electrolyte Membranes Prepared by Blending Sulfonated Polystyrene with Lignosulfonate
Get PDFA polymer electrolyte membrane widely used in PEMFCs and DMFCs is a perfluorosulfonated membrane (the Nafion membrane). This perfluorosulfonated membrane material exhibits good chemical stability and proton conductivity, but it is very expensive and difficult to recycle. There is a high methanol crossover in DMFCs that causes a decrease in efficiency and performance of the fuel cell, so that a polymer electrolyte membrane with a low methanol crossover is needed as a substitute for the Nafion membrane. One of the materials that can be used as a polymer electrolyte membrane is the polyblends from sulfonated polystyrene-lignosulfonate (SPS-LS). Such polyblends were prepared by casting a polymer solution and characterized as polyelectrolyte membrane for DMFCs. The SPS was prepared by sulfonation of polystyrene with acetyl sulfate as the sulfonating agent. The membranes of the SPS-LS were characterized by analysis of functional groups, mechanical properties and methanol permeability. The maximum mechanical properties of the SPS-LS membrane were observed at an LS ratio of 7.5%. However, the methanol permeability of the membrane increased with the increase of the LS ratio in the SPS-LS membranes. The properties of the membranes, especially their mechanical properties and methanol permeability, were close to that of Nafion® 117 membrane, so SPS-LS membranes have high potential for use as polymer electrolyte membrane for direct methanol fuel cells
Dynamical Model for Transmission of West Nile Virus in Chicken-Mosquito Interaction
Get PDFThe West Nile virus (WNV) is transmitted through the bites of infected mosquitoes. The spread of WNV in chicken populations is quite unique. Although chickens can contract the virus through a mosquito bite, they immediately build immunity to the virus and do not show physical symptoms of illness and hence chickens are only temporary carriers of the virus. Recently, experimental results have shown that mosquitoes do not change fecundity behavior, yet results indicate that resistance to infection is associated with afitness cost in terms of mosquito survival. We constructed a host-vector type transmission model for WNV in mosquito-chicken populations. The basicreproductive ratio, Ro , was obtained. From sensitivity analysis of Ro it was shown that under certain conditions this ratio decrease "“ with an increase of the lifetime of mosquito infection
Marmin of Aegle Marmelos Correa Antagonizes AChM3 Receptors: In Silico and In Vitro Studies on Isolated-Guinea Pig Illeum Smooth Muscle
Get PDFMarmin is a coumarin derivative compounds isolated from the bark and roots of Aegle Marmelos Correa. Previously, ethanolic extract of leaves of Aegle Marmelos Correa on isolated ileum showed antagonism effect on the contraction induced by histamine. Besides H1 receptor, there is also muscarinic acetylcholine (AChM)receptors involved in the mechanism of ileum contraction. Marmin is predicted to antagonize on AChM3 receptors.This study aimed to determine the effect of marmin on smooth muscle contraction of isolated guinea pig ileum induced by metacholine, an agonist of AChM3 receptor. The method in the study were in vitro (isolated organ) and in silico (docking PLANTS). In the in vitro study, marmin exhibited a competitive antagonists effect at the concentration of 100 μM (pA2 value of 1,728) on the AChM3 receptors. Reversibility assay on AChM3 receptors showed that by washing the ileum with Tyrode buffer every 6 minutes for 30 minutes, the bond of marmin to the receptor was still not completely detached. In the in silico study, marmin was observed to be bound to AchM3 receptors (docking score: -102.086). Marmin bond was weaker than that of native ligand of AChM3 receptor (tiotropium, docking score: -115.107), however, stronger than that of AChM3 receptor agonist and antagonist. Based on the results, we conclude that marmin have a competitive antagonist activity on AChM3 receptor
Litsea cubeba Essential Oil Yield Harvested from Different Habitat Types on Mt. Papandayan, West Java, Indonesia
Get PDFThe objective of this research was to determine the yield and chemical composition of Litsea cubeba essential oil harvested from different habitat types on Mount Papandayan, West Java, Indonesia. The methods used were determination of sample plots at each habitat, followed by laboratory testing. Leaf samples were taken from each plot, the oil was extracted in the laboratory using steam distillation, which was subsequently analyzed by GC-MS. The results showed that the yield of essential oil was high (2.76-9.33%). The three dominant chemical compounds found were eucalyptol (16.97-55.78%), α-terpinenyl acetate (7.27-20.44%), and sabinene (14.45-68.05%). The results confirmed the expectation that Litsea cubeba essential oils extracted from Litsea cubeba trees growing in various habitats on Mount Papandayan would show a variety in yield and chemical composition