Journal of Mathematical and Fundamental Sciences
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New Generalized Algorithm for Developing k-Step Higher Derivative Block Methods for Solving Higher Order Ordinary Differential Equations
Get PDFThis article presents a new generalized algorithm for developing k-step (m+1)th derivative block methods for solving mth order ordinary differential equations. This new algorithm utilizes the concept from the conventional Taylor series approach of developing linear multistep methods. Certain examples are shown to show the simplicity involved in the usage of this new generalized algorithm
Poly(urethane) synthesized from 9-ethoxy-1,10-octadecanediol obtained by modification of palm oil oleic acid
No full textPoly(urethane) (PU) as a prepolymer was prepared by polymerization of the diol compound (9-ethoxy-1,10-octadecanediol) and 4,4-methylen-bis phenyl isocyanate (MDI) under nitrogen atmosphere at 85 °C. The 9-ethoxy-1,10-octadecanediol was obtained by several reaction steps, i.e. epoxydation of oleic acid obtained from palm oil, ring-opening of oleic acid epoxide, and reduction of oleic acid ester. All compounds obtained in this work were characterized by chemical structure analysis (FTIR and 1H NMR), supported by analysis of iodine value, acid value, and hydroxyl value determined by titration methods and thermal analysis, especially for poly(urethane). The 9-ethoxy-1,10-octadecanediol as the diol compound for preparation of poly(urethane) was analyzed by FTIR, supported by hydroxyl numbers determined by titration. Poly(urethane-urea) (PUU) was obtained by addition of ethylene diamine as chain extender to poly(urethane). The thermal stability of poly(urethane-urea) is higher than that of poly(urethane). The addition of ethylene diamine as chain extender in poly(urethane) can improve the intrinsic viscosity of polymer to form poly(urethane-urea). These results are supported by chemical structure analysis
Multi-wavelength Fibril Dynamics and Oscillations above Sunspot-II Wave Propagation Signature
Get PDFIn this work, the dynamics of one particular fibril were investigated through high-resolution multi-wavelength images with high cadence obtained from the Dutch Open Telescope. Based on exceptional observation data of Active Region 10789, 13th July 2005, we investigated the alternating fibril pattern using tomography of the multi-wavelength band, consisting of the hydrogen alpha line center and also the blue wing, the calcium II H line, and the G-band. Phase difference and coherence analyses were conducted for several points along the fibril and (k, ω) analysis was conducted to understand the wave interaction and its mechanism in the propagation process. Our findings suggest short- to long-period transitions along the fibril with coherence in 10-min oscillations in the penumbra
Development of a Low-Cost TiO2/CuO/Cu Solar Cell by using Combined Spraying and Electroplating Method
Get PDFA simple method is proposed to develop a low-cost TiO2/CuO/Cu based solar cell. The cell is made by employing a lower grade (technical grade) of TiO2 as the active material. CuO powder is synthesized using a wet chemical method and mixed with TiO2 powder to give impurity to the TiO2. A layer of TiO2/CuO is then deposited onto fluorin-doped tin oxide (FTO) by spraying. Copper particles are grown on the spaces between the TiO2 and/or CuO particles by electroplating for more feasible electron migration. The TiO2/CuO/Cu solar cell is finalized by sandwiching a polymer electrolyte between the film and the counter electrode. Current-voltage measurement was performed for various parameters, such as the molarity of NaOH for producing CuO particles, the weight ratio of CuO over TiO2, and the current in the electroplating process. A highest efficiency of 1.40% and a fill factor of 0.37 were achieved by using this combined spray and electroplating method
Tree Community Structure and Composition of a One-Hectare Permanent Plot in the Montane Zone of Mount Kerinci, Kerinci Seblat National Park, Jambi
Get PDFInformation on tree community structure and composition is needed in forest management and restoration. These data can be obtained using a permanent plot for studying forest dynamics, including species-specific characteristics. These characteristics are useful in the identification of native species for commercial and restoration purposes. This study aimed to describe the tree community structure and composition of a one-hectare permanent plot in the montane zone of Mount Kerinci. Data collection was conducted from July to August 2016 on Mount Kerinci, Jambi. A plot was established at 2,182-2,258 m above sea level and subdivided into 100 subplots. All trees ≥ 10 cm DBH were tagged and measured. Twenty-eight species, 18 genera, 20 families, 570 individuals and Shannon index 2.89 were identified. Most of the potential species richness was covered on the research site. Syzygium lineatum was the species with the highest importance value and Myrtaceae had the highest family importance level. The study area was dominated by slow growing species that characterize primary forests. The population structure indicated a good capacity of forest regeneration, while the vertical structure formed a stratification consisting of three strata. The dominant large trees and 5 hyperdominant trees according to total biomass contribution were identified. These species are an important priority in forest management and restoration.
Genetic Diversity of Indigofera tinctoria L. in Java and Madura Islands as Natural Batik Dye based on Inter-simple Sequence Repeat Markers
Get PDFIndigo leaves (Indigofera tinctoria L.) are utilized as a source of batik dye in Java and Madura islands, Indonesia. Batik makers from the islands collect indigo leaves from wild plants. Continuous collection of wild plants from their natural habitat may decrease their diversity. The present research was conducted to analyze the genetic diversity and population structure of I. tinctoria L. from Java and Madura. 55 indigo accessions were collected from 10 locations in Java and Madura. The indigo DNA was extracted and amplified using 15 ISSR primers. A total of 123 bands showed 50-90% polymorphic loci. PCA and UPGMA were used to analyze the data. All indigo accessions were clustered into 4 groups at a 60% similarity coefficient: a group consisting of Madura accessions, a group consisting of East Java accessions, a group consisting of Central Java accessions, and a group consisting of West Java accessions. Accessions collected from the same or adjacent populations tended to show similar ISSR characteristics. The genetic diversity of indigo in Java and Madura islands is relatively high (%P = 68.3), but the diversity residing within each population is lower (37%) than that between populations (63%)
On The Partition Dimension of Disconnected Graphs
Get PDFFor a graph G=(V,E), a partition Ω={O1,O2,"¦,Ok} of the vertex set V is called a resolving partition if every pair of vertices u,v ∈ V(G) have distinct representations under Ω. The partition dimension of G is the minimum integer k such that G has a resolving k-partition. Many results in determining the partition dimension of graphs have been obtained. However, the known results are limited to connected graphs. In this study, the notion of the partition dimension of a graph is extended so that it can be applied to disconnected graphs as well. Some lower and upper bounds for the partition dimension of a disconnected graph are determined (if they are finite). In this paper, also the partition dimensions for some classes of disconnected graphs are given