Journal of Mathematical and Fundamental Sciences
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Studi Penumbuhan Film Tipis Ti1-xCoxO2 dengan Teknik MOCVD Menggunakan Prekursor Titanium (IV) Isopropoxide dan Tris (2,2,6,6-tetramethyl-3, 5-heptanedionato) Cobalt (III)
Get PDFThe Ti1-xCoxO2 thin films have been grown by MOCVD technique using titanium (IV) isopropoxide (TTIP) and tris (2,2,6,6-tetramethyl-3, 5-heptanedionato) Cobalt (III) [Co(TMHD)3] powder precursors. The tetrahydrofuran (THF) were used as a solvent to get a Co(TMHD)3 solution. Characteristics of precursor and growth parameters were investigated. The Co concentration in thin films were varied. The room temperature ferromagnetic properties of Ti1-xCoxO2 thin films were obtained. Solubility of Co atom in TiO2 lattice were found at about 11%. The surface morphology of films are homogen and relatively smooth
Determining Velocity and Q-factor Structure using Crosshole Tomography
Get PDFIn this study, we have conducted a crosshole tomography survey to obtain seismic data from two boreholes on the ITB campus. The first borehole was 39 meters deep while the second was 19 meters deep. The aim of the study was to determine the subsurface velocity and Q-factor for the region between the two boreholes for geotechnical purposes. Sources of seismic waves were produced by an impulse generator and sparker and were recorded by 12 channels of borehole hydrophones. In the tomography inversion, the pseudo-bending ray tracing method was employed to calculate travel times. The initial velocity model was a 1-D model with 1x1 m2 block dimensions. The non-linear inversion problem was solved by delay-time tomography with the LSQR method. Also, a checkerboard resolution test (CRT) was conducted to evaluate the resolution of the tomography inversion. Using the velocity structure results, a LSQR Q-tomography inversion was carried out using spectral curve fitting to obtain the attenuation structure (t* values). The resulting tomogram shows that there are 3 layers, with an unconsolidated layer (down to 8 meters), a consolidated layer (from 8 meters deep to 20 meters), and bedrock (more than 20 meters). From the results, the ground water level is estimated at a depth of 14 meters
A Note on Strongly Lower Semi-Continuous Functions and the Induced Fuzzy Topological Space Generated by Them
Get PDFA new class of functions called strongly lower semi-continuous (SLSC) functions is defined and its properties are studied. It is shown that the arbitrary supremum and finite infimum of SLSC functions are again SLSC. Using these functions, an induced fuzzy topological space, called s-induced fuzzy topological space on a topological space (X, T), is introduced. Moreover, some incorrect results on fuzzy topological spaces obtained previously by some authors are identified and modified accordingly. Examples of the newly defined induced space are given and their various properties are investigated. Interrelationships between a fuzzy topological space (X, F) and the s-induced fuzzy topological space generated by the crisp members of F are examined. In this process, different lower semi-continuities and induced fuzzy spaces generated by them have been defined in a general set up and their few properties have been studied
Tight Wavelet Frame Decomposition and Its Application in Image Processing
Get PDFThis paper is devoted to the formulation of a decomposition algorithm using tight wavelet frames, in a multivariate setting. We provide an alternative method for decomposing multivariate functions without accomplishing any tensor product. Furthermore, we give explicit examples of its application in image processing, particularly in edge detection and image denoising. Based on our numerical experiment, we show that the edge detection and the image denoising methods exploiting tight wavelet frame decomposition give better results compare with the other methods provided by MATLAB Image Processing Toolbox and classical wavelet methods
Structure and Properties of Polymers Prepared by Polymerization of 2,2-Dimethyl-1,3-Propandiol and ε-Caprolactone Monomer
Get PDFPoly(ε-caprolactone) (PCL) is very attractive synthetic polymer due to its properties, such as a high permeability, the lack of toxicity, and also biodegradability. However, it has limited application because of low melting point (60 °C), high crystallinity, and brittleness. The aim of the experiments is designed to improve the properties of PCL by formation of their polymers with 2,2-dimethyl-1,3-propandiol monomers with various chain length as a raw material to prepare poly(urethane-ester). These polymers were synthesized by a ring-opening polymerization of 2,2-dimethyl-1,3-propandiol and ε-caprolactone monomers in various composition in the presence of 1-hydroxy-3-chloro-tetraisobuthyldistanoxane as a catalyst. Polymers were characterized by analysis of functional groups (FTIR), microstructure (1H and 13C NMR), viscosity, hydroxyl number, and also melting point of polymers (DSC). Based on the structure analysis indicate that polymerization of 2,2-dimethyl-1,3-propandiol and ε-caprolactone monomers produced polymers with various molecular weights, which depend on the ratio of ε-caprolactone / 2,2-dimethyl-1,3-propandiol used in polymerization. The reactivity of CL monomer decreases to the active site of polymers with longer chain size. The melting points of polymers increase with the increasing of ε-caprolactone composition used in polymerization, whereas hydroxyl number decreases
Band Alignment and Optical Properties of (ZrO2)0.66(HfO2)0.34 Gate Dielectrics Thin Films on p-Si (100)
Get PDF(ZrO2)0.66(HfO2)0.34 dielectric films on p-Si (100) were grown by atomic layer deposition method, for which the conduction band offsets, valence band offsets and band gaps were obtained by using X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy. The band gap, valence and conduction band offset values for (ZrO2)0.66(HfO2)0.34 dielectric thin film, grown on Si substrate were about 5.34, 2.35 and 1.87 eV respectively. This band alignment was similar to that of ZrO2. In addition, the dielectric function ï¥(k, ω), index of refraction n and the extinction coefficient k for the (ZrO2)0.66(HfO2)0.34 thin films were obtained from a quantitative analysis of REELS data by comparison to detailed dielectric response model calculations using the QUEELS-ε (k,ω)-REELS software package. These optical properties are similar with ZrO2 dielectric thin films
Bergenin, Suatu Dihidroisokumarin dari Kayu dan Kulit Batang Shorea Stenoptera Burck§
Get PDFBergenin, a dihydroisocoumarin derivative of glucopyranosyl gallic acid had been isolated for the first time from ethyl acetate extracts of the heartwood and tree bark, together with (-)-α-viniferin from the tree bark of Shorea stenoptera. The structure of bergenin was elucidated based on analysis of spectroscopic data UV, IR, MS, 1H and 13C NMR. Bergenin showed weak cytotoxic activity against murine leukemia P-388 cells (IC50 >100 μg/mL), and also weak toxicity against Artemia salina shrimps (LC50 >500 μg/mL)
Pengaruh Jenis Poliol terhadap Pembentukan Poliuretan dari Monomer PEG400 dan MDI
Get PDFThe properties of polyurethane depend largely on building blocks, especially the kind of polyol. Not only pure synthetic compounds but also various natural substances such as saccharides (glucose, fructose, maltose, sucrose) and amylose can be used as possible resources of polyol in polyurethane synthesis. Those natural substances are natural polymeric materials having appropriate reactivity thank to its functional groups such as hydroxyl groups. Natural polymers having more than two hydroxyl groups per molecule can be used as polyols for polyurethane synthesis. In this study, the effect of addition of saccharide (glucose, maltose) and amylose in the synthesis polyethylene glycol 400 (PEG400) and methylene-4,4'-diphenyldiisocyanate (MDI) based polyurethane was studied by measuring the hydrogen bonding index (HBI) and the thermal properties. Characterization of functional groups in resultant polyurethane was analyzed by FTIR spectrophotometry, the thermal properties were conducted with Differential Thermal Analysis (DTA), Differential Scanning Calorimetry (DSC), and Thermal Gravimetric Analysis (TGA). The addition of saccharide (glucose, maltose) and amylose on the synthesis polyurethane from polyethylene glycol 400 (PEG400) and methylene-4,4'-diphenyldiisocyanate (MDI) can increase the hydrogen bonding index and the glass transition temperature of polyurethane. In all case the increase of glucose unit in polyol can increase the hydrogen bonding index, the glass transition temperature, and the thermal stability of polyurethane
Pengujian Prototip Suspensi Aktif Tegar (Robust) Model Seperempat Kendaraan
Get PDFIn this paper the result of the performance test of a robust-active suspension system will be presented. The performance of the developed suspension system was evaluated under a sinusoidal road disturbance with amplitude of 3 mm (peak to peak), and within the frequency test range of 1 "“ 9 Hz. The experimental results show that in the frequency test range of 1 "“ 4 Hz, the sprung mass acceleration of the active suspension is smaller than that of the passive suspension. However, the sprung mass acceleration of the active suspension is higher than that of the passive one, in the frequency test range of 5 "“ 9 Hz. Moreover, the unsprung mass acceleration of the active suspension is smaller than its passive counterpart in all of the frequency test range 1 "“ 9 Hz
Aspek Geodetik Penegasan Batas Darat Indonesia dan Papua New Guinea: Status dan Permasalahannnya
Get PDFTechnical problems of land boundary between Indonesia and Papua New Guinea are related to delimitation and demarcation process that has been done by two countries. The process did not explicitly the datum and reference frame being used in reconstructing of monuments border pursuant to the agreement of meridian in article-1 of boundary agreement of 1973. The uncertainty about the datum caused demarcation process has been done using different datum. The datums are astronomic and geodetic datum. The combination of the coordinate derives from respectively datum to reconstruct the agreement of meridian caused technical problems and implication to status of land boundary of both countries. This paper investigates about status and technical problems of land boundary between Indonesia and Papua New Guinea and its alternative solution. Investigation is done using the boundary monuments coordinate given by GPS survey of 2004 and boundary monuments coordinate pursuant to boundary agreement of 1973 and result of demarcation survey of 1983-1991. This paper is sum up with some conclusions and recommendation