Journal of Mathematical and Fundamental Sciences
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Instability of Non-Linear Functional Differential Equations of Fifth Order
Get PDFIn this paper, we study the instability properties of solutions of a kind of functional differential equations of the fifth order with constant delay. Using the Lyapunov-Krasovskii functional approach, we obtain certain sufficient conditions to guarantee that the zero solution of the equation is unstable
A Singular Perturbation Problem for Steady State Conversion of Methane Oxidation in a Reverse Flow Reactor
Get PDFThe governing equations describing methane oxidation in a reverse flow reactor are given by a set of convective-diffusion equations with a nonlinear reaction term, where temperature and methane conversion are dependent variables. In this study, the process is assumed to be a one-dimensional pseudohomogeneous model and takes place with a certain reaction rate in which thewhole process ofthereactor is still workable. Thus, the reaction rate can proceed at a fixed temperature. Under these conditions, we can restrict ourselves to solving the equations for the conversion only. From the available data, it turns out that the ratio of the diffusion term to the reaction term is small. Hence, this ratio is considered as a small parameter in our model and this leads to a singular perturbation problem. Numerical difficulties will be found in the vicinity of a small parameter in front of a higher order term. Here, we present an analytical solutionby means of matched asymptotic expansions. The result shows that, up to and including the first order of approximation, the solution is in agreement with the exact and numerical solutions of the boundary value problem
Modified Convective Stratiform Technique (CSTm) Performance on Rainfall Estimation in Indonesia
Get PDFThis study has analyzed a rainfall estimation using a modified convective stratiform technique (CSTm). Unlike the original convective stratiform technique (CST), which only utilizes infrared (IR) data, CSTm applies not only IR data but also passive microwave (PMW) data. Two major modifications contained in CSTm are: (1) the application of a variability index (VI) method that uses PMW data to perform convective and stratiform separation,and (2) the ability to determine the average extensive coverage of the new areas of each pixel point as a result of the utilization of the PMW data. In this study, rainfall estimation was conducted for 23 points spread over four major islands in Indonesia. The estimation was performed based only on IR and PMW data obtained from coincident observations. For verification, the estimation results were compared with real observations. The main verification action conducted in this study used multi-category contingency tables for four categories and this action was supported by the root mean square error (RMSE)method.The verification results of the hourly estimation conducted for 4 days in early November 2011 showed that CSTm can effectively improve the performance quality of CST
Source Processes of the March 2007 Singkarak Earthquakes Inferred from Teleseismic Data
Get PDFThe rupture processes of two sequentialearthquakes have been inverted from teleseismic data. The first event released a total seismic moment of 7.9×1018 Nm (Mw 6.5) and the slip distribution shows three asperities, 1.5 m at the shallowside, 0.7 m at the rightsouth-east deep side and 0.5 m atthe north-west deep side. The second event had one asperity with 1.7 m slip and released a seismic moment of 7.5×1018 Nm (Mw 6.5). In both cases, maximum slip occurred above the hypocenter which was responsible for the surface displacement pattern
Unexpected Outcomes: Propagating Light Rays in the Atmosphere, a New Technique for Solving Partial Differential Equations
Get PDFProblems that arise out of an industrial context normally have clear cut objectives, and the results are usually important in context but of limited general interest. Sometimes, however, the investigations lead to results that are both unexpected and of much broader interest. Two such investigations are described here. In the first problem an investigation of the propagation of light rays across the ocean leads to new results concerning optical distortion. In the second problem a surface tension investigation leads to an entirely new technique for solving partial differential equations
Open Neighborhood Coloring of Prisms
Get PDFFor a simple, connected, undirected graph G(V, E) an open neighborhood coloring of the graph G is a mapping f : V (G) --> Z+ such that for each w in V(G), and for all u, v in N(w), f(u) is different from f(v). The maximum value of f(w), for all w in V (G) is called the span of the open neighborhood coloring f. The minimum value of span of f over all open neighborhood colorings f is called open neighborhood chromatic number of G, denoted by Xonc(G). In this paper we determine the open neighborhood chromatic number of prisms
Synthesis of Polymer Electrolyte Membrane based on Acid-Base complex pair and Its Characteristics
Get PDFIn this work, acid-base complex pair polymer electrolyte membranes on sulfonated polysulfone with 1H-benzotriazole were investigated. Polysulfone was sulfonated in 1,2-dichloroethane using the homogeneous method with trimethylsilyl chlorosulfonate as sulfonating agent. The monomer mole ratio between polysulfone and trimethysilyl chlorosulfonate was 1:1.5.The sulfonated polysulfone was added with 1H-benzotriazole at mole ratios of x = 0.5 and x =1. The proton transfer from 1H-benzotriazole to the sulfonated polysulfone was measured using FTIR. Thermo-gravimetry analysis showed that the samples were thermally stable up to approximately 250°C and the maximum proton conductivity was found to be 3.34 x 10-4 S cm-1 at 150°C
Analysis of MaACS2, a stress-inducible ACC Synthase Gene in Musa acuminata AAA Group Cultivar Pisang Ambon
Get PDFEthylene has an important function in plant growth and development. Ethylene production generally increases in response to pathogen attacks and other environmental stress conditions. The synthesis of this phytohormone is regulated by two enzymes, ACC synthase (ACS) and ACC oxidase (ACO). ACC synthase is encoded by a multigene that regulates the production of ACC, after which this precursor is converted into ethylene by ACO. Pisang Ambon (Musa sp. AAA group), a banana cultivar originating from Indonesia, has nine ACS genes (MaACS 1-9) and one ACO gene (MaACO). One of the banana ACS genes, MaACS2, is stress-inducible. In this research, we have investigated the expression profile of MaACS2 in the roots and leaf tissues of infected tissue culture plants. Quantification of gene expression was analyzed using Real-Time PCR (qPCR) using Ma18srRNA and MaGAPDH as reference genes. The results showed nine-to ten fold higher MaACS2 expression levels in the infected roots tissues compared to the uninfected roots tissues. However, MaACS2 expression in the leaves was only detected in infected tissue
Induction of Somatic Embryos from Leaf and Stem Nodal Section Explants of Potato (Solanum tuberosum L.)
Get PDFSomatic embryogenesis can be used as an alternative method to obtain high-quality potato seedlings. This research was conducted in order to evaluate: the potential of different types of explants to produce somatic mbryos;combinations of 2,4-D and BAP for somatic embryo induction; and the ability of BAP to act as growth regulator for the somatic embryo maturation process.Young leaf and stem nodal sections were cultured in MS media supplemented with 2,4-D and BAP. The developing calli were then transferred into media containing several concentrations of 2,4-D and BAP. The embryogenic calli were then transferred into media containing 1-5 μM BAP. The results show that MS media containing 2,5 μM 2,4-D + 5 μM BAP and μM 2,4-D + 0.5 μM BAP were the most suitable for inducing somatic embryos from leaf explants and stem nodal section explants, respectively. The somatic embryos were well-developed in the MS media supplemented with 5 μM BAP. The stem nodal section explants were able to produce a higher percentage of globular, heart and torpedo stage embryos compared with the leaf explants. Based on this research, stem nodal section explants have a high potential for producing somatic embryos induced in medium containing 1 μM 2,4-D + 0.5 μM BAP
New Hermitian self-dual MDS or near-MDS codes over finite fields
Get PDFA linear code over a finite field is called Hermitian self-dual if the code is self-dual under the Hermitian inner-product. The Hermitian self-dual code is called MDS or near-MDS if the code attains or almost attains the Singleton bound. In this paper we construct new Hermitian self-dual MDS or near-MDS codes over and of length up to 14