Makara Journal of Science
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PENGARUH JANGKAU SUDUT UKUR PADA HASIL ANALISIS DATA DIFRAKSI SINAR-X MENGGUNAKAN METODE RIETVELD: KASUS CAMPURAN MgO-Y2O3
No full textSelection of Diffraction Measurement Range and Its Effect on X-ray Diffraction Rietveld Analysis Results: a MgO-Y2O3 Mixture Case. X-ray diffraction data analyses for a MgO-Y2O3 (30% Y2O3 by weight) ceramic composite have been done at various diffraction angle ranges to evaluate the effects to the analyses results. The study was performed as choosing the angle ranges correlates to data collection time and x-ray tube lasting. The analyses utilised Rietveld-based software Rietica. The ranges chosen were (A) 10-100, (B) 10-90, (C) 10-80, (D) 10-70 dan (E) 10-60 °2θ. Results showed that in general the errors of the refined parameters increased with narrower range. Phase composition analyses also showed significant bias when narrower range was used – with range 10-80 °2θ gave tolerable result. Moreover, narrowing diffraction angle in the analysis significantly biases the Lorentzian peak broadening component values particularly for phase with crystallite size estimate more than 100 nm. The study recommends how to choose the range. Keywords: diffraction range, x-ray diffraction, MgO-Y2O3, Rietveld analysi
STRUKTUR KECEPATAN S ANTARA GEMPA C081499A, SUMATERA SELATAN DAN STASIUN OBSERVASI RER
No full textThe research investigated the S speed of earth structure under Indian Ocean using seismogram fitting, due to the C081499A earthquake, South Sumatra and recorded in the observation station RER at Reunion Island, France. The observed seismogram is compared to its synthetic in time domain and three cartension components simultaneously. Synthetic seismogram is calculated with the GEMINI program, the initial inputs are the global earth models of Ocean and PREMAN. Prior to seismogram comparison, a low-pass filter with corner frequency of 20 mHz is imposed. The result of analysis shows a very strong deviation at the arrival time, oscillation amount and amplitude height of Love and Rayleigh surface waves and S body wave. To overcome the found discrepancies a correction to the earth structure is needed covering the earth crust thickness, speed gradient of βh and zero-order coefficient for the βh and βv in upper mantle, and a little change in S speed in earth layers down to a depth of 400 km. Seismogram fitting is better obtained at waveform of the wave phase, either the travel time or oscillation number of S wave and Love surface wave. The results shows that the Indian Ocean has correction to the S speed structure, which is positive to standard earth model. This result differs from other seismology research. Keywords: seismogram analysis, S velocity model, Indian Ocean  
Pengaruh Peningkatan Flow Rate Gas Metan Terhadap Sifat Optis L
No full textMethane Flow Rate Effects On The Optical Properties of Amorphous Silicon Carbon (a-SiC:H) Films Deposited By DCSputtering Methods. We have investigated the refractive index (n) and the optical absorption coeffi cient (α) from refl ectionand transmission measurements on hydrogenated amorphous silicon carbon (a-SiC:H) fi lms. The a-SiC:H fi lms were prepared by dc sputtering method using silicon target in argon and methane gas mixtures. The refractive index (n) decreases as the methane fl ow rate increase. The optical absorption coeffi cient (α) shifts to higher energy with increasing methane flowrate. At higher methane fl ow rate, the fi lms tend to be more disorder and have wider optical gap. The relation of the optical properties and the disorder amorphous network with the compositional properties will be discussed. Keywords: Refractive index, optical absorption coeffi cient, optical gap, amorphous silicon carbon, sputterin
AKTIVITAS LIPOLITIK Rhizopus microsporus var. rhizopodiformis ISOLAT UICC No. 6
No full textThe lipolytic activity of Rhizopus microsporus var rhizopodiformis isolat UICC No. 6. A study was carried out to examine the effect of peptone concentration (2,5% or 5%), inoculum concentration (0,1%, 0,5% or 1%) and incubation period (0 – 96 hours, interval 12 hours) on the lipolytic activity of Rhizopus microsporus var rhizopodiformis isolat UICC No. 6. Fermentation was done using the basal medium from Samad and the lipolytic activity on olive oil substrate was measured employing titration method with 0,05M NaOH. Lipolytic activity is expressed as unit/ml and one unit is defined as 1 mol fatty acid liberated per minute. Results show that optimum lipolytic activity was obtained from 1 % inoculum, 5% peptone after 72 hours incubation period.Keywords: lipolytic, Rhizopus, inoculum, incubatio
PERBAIKAN GEOMETRIK TRASE JARINGAN JALAN DENGAN MENGGUNAKAN TEKNOLOGI PENGINDERAAN JAUH DAN SISTEM INFORMASI GEOGRAFIS
No full textGeometric Improvement Of Trace Network Road with Remote Sensing and Geographic Information System. Together with a great development in road network at such district, it must be followed by changing information that should be suited to the condition at present. For supporting the information changes, the remote sensing technology could be applied. It is one of technology with a great increment and needed to various applications. The application of remote sensing technology is close related to spatial field which is used to be achieved from non digital because of limitation facilities and other obstacle. However with remote sensing technology, those can not be burdened anymore and the information achieved can be updated. The presence of remote sensing technology is followed by emerging of Geographic Information System technology which promises a new era in providing deep information and spatial object analysis. The object identification through Landsat Thematic Mapper (LTM) image with (30x30) meter spatial and 7 (seven) band spectral resolution. The composite image together with image contrast improvement are applied to supervised classification covered object for obtaining classified and corrected image that can be used to analyze network road improvement and create database information of trace network road using Geographic Informationsystem.Keywords: Trace network road, remote sensing, landsat thematic mapper, coverage, geographic information syste
SPEKTROSKOPI INFRAMERAH SENYAWA KALSIUM FOSFAT HASIL PRESIPITASI
No full textInfrared Spectroscopy of Precipitated Calcium Phosphate Compound. Samples of calcium phosphate compounds were produced from saturated solutions containing of calcium and phosphate ions. The experiments were carried out using solutions at temperature 25 ºC and 70 ºC, combined with different pH value of 5, 7, 9 and 11. Precipitation massfrom solutions at 70 ºC was relatively higher compare to that produced from solutions at 25 ºC. It was also shown that generally the mass precipitation rose with the increasing of pH. Sample analyses were performed with the use of infrared spectroscopy, particularly for the samples produced from solutions at 70 ºC. Based on the ν4 phosphate absorption band, it was indicated that apatite crystals found in most samples which its amount gave rise to the increasing of pH. Infrared spectroscopy of the heated samples produced with pH 11 showed that water molecules could be present either at the surface of crystals or trapped in the crystal structure.Keywords: calcium phosphates, apatite crystals,infrared spectroscop
STUDI IN SILICO MODIFIKASI POS TRANSLASI DISAIN VAKSIN CHIMERIC BERBASIS VIRUS LIKE PARTICLES HUMAN PAPILLOMAVIRUS DENGAN KAPSID VIRION L1
No full textComputational Study of Post Translation Modification in Chimeric Virus Like Particles Vaccine of Human Papilloma Virus with Virion Capsid L1. The Human Papillomavirus (HPV) infection has a tight correlation with the incidence of cervical cancer. Chimeric virus like particles (cVLP) has been developed as vaccine candidate for preventing cervical cancer. cVLPs are improvement of Virus Like Particles (VLP) by substituting the epitope of L1 HPV -18 and -52 protein to L1 HPV -16 protein. They are ANN1, ANN2, HMM1, and HMM2. The impact of post translation modification will be determined. Based on In Silico study, the dominant post translation modification is glycosylation. Keywords: cVLP, HPV, Cervical Cancer, Vaccine, Post Translation Modification, hos
SISTEM PENGENALAN WAJAH 3-D MENGGUNAKAN PENAMBAHAN GARIS CIRI PADA METODE PERHITUNGAN JARAK TERPENDEK DALAM RUANG EIGEN
No full text3-D Face Recognition System using Additional Feature Lines in Nearest Feature Line Method in Eigenspace Representation. In this paper, the authors propose a new method in 3-D face recognition system using additional feature lines in Nearest Feature Line method, called the Modified Nearest Feature Line method. The additional feature lines can be acquired by projecting each feature point to other feature lines in the same class without increasing the number of feature points. With these additional lines, the system will have the ability to capture more variations of face images, so it can increase the recognition rate of the system. The authors also propose KL-TSubspace1 and KL-TSubspace2 as methods in transforming the 3-D face images from its spatial domain to their eigenspace domain. The experiments use the 3-D human faces of Indonesian people in various expressions and positions. Then, the system is applied to recognize unknown face images with different viewpoints. Experimental results shown that the system using KL-TSubspace2 and Modified Nearest Feature Line method can have the highest recognition rate of 99.17%.Keywords: 3-D face recognition system, nearest feature line method (NFL), modified nearest feature line method(MNFL), Karhunen-Loeve transformation, eigenspace representatio
X-RAY DIFFRACTION PHASE ANALYSES FOR GRANULATED AND SINTERED CERAMIC MATERIALS
No full textOne basic problematic aspect in x-ray diffraction phase analysis is microabsorption effect which may arise from the size of the crystallite phases. Complication of the problem may intensify in sintered ceramic materials where milling of the samples is not simple. We report the Rietveld x-ray diffraction phase analysis of MgO--Al2O3 powder mixtures with phase content ratio of 1:1 by weight and MgO-Y2O3 sintered ceramic composites with Y2O3 contents of 10%, 20% and 30% by weight. The mixtures were pre-sintered at 1000C for 2 hours and then milled while the composites were sintered at 1550C for 3 hours. The phase composition analysis was done using Rietica, a non-commercial Rietveld method-based software. Relative and absolute phase compositions were examined and results showed that there was a significant amount of phase composition bias resulted from the examination. For the powder mixture, milling can reduce microabsorption effect and hence the calculation bias. For the ceramic composite where milling is almost impossible, additional of Y2O3 caused smaller crystallite size of MgO, so that composition bias is smaller in composites with higher Y2O3 content. A mathematical model is proposed to provide more acceptable phase composition results. Keywords: Rietveld phase analysis, MgO-Y2O3 composites, sintered ceramic
KAJIAN KEMAMPUAN GENERALISASI SUPPORT VECTOR MACHINE DALAM PENGENALAN JENIS SPLICE SITES PADA BARISAN DNA
No full textStudy on Generalization Capability of Support Vector Machine in Splice Site Type Recognition of DNA Sequence. Recently, support vector machine has become a popular model as machine learning. A particular advantage of SVM over other machine learning is that it can be analyzed theoretically and at same time can achieve a good performance when applied to real problems. This paper will describe analytically the using of SVM to solve pattern recognition problem with a preliminary case study in determining the type of splice site on the DNA sequence, particularity on the generalization capability. The result obtained show that SVM has a good generalization capability of around 95.4 %.Keywords: Support vector machine, generalization test, pattern recognition, splice sites, DN