MAKARA Journal of Technology
Not a member yet
243 research outputs found
Sort by
KLASIFIKASI OBJEK DALAM VISI KOMPUTER DENGAN ANALISIS DISKRIMINAN
Get PDFA robotic sensor system is always supported by a computer system called 'computer vision'. The important conceptof computer vision is object classfifi cation. In this study two algorithms for object classifi cation in this system will becompared. Firstly, A simple method that do not need complex computation and that considered as an informal method iscalled binary tree decision structure. This method is based on modest caracteristic decriptors of an object such as verticalline, horizontal line or ellipse line. Unfortunately this method has weakness in recognize an image that contaminated by anoise. Secondly, a more formal method with high variability descriptors. In this contect a multivariate statistical approachnamed discriminant analysis is proposed as an alternative for object classifi cation. This method is operated by computationof a function called Fisher discriminant function that can be used for separating an object. From the data simulation andanalysis for calssifi cation of two object i.e. screw and bolt and three objects i.e. alphabet T,O and S it can be shown thatdiscriminant analysis approach can classify an object better than binary decision algorithm. The superority of discriminantmethod is especially seen when this method is applied for classifi cation of a noisy image of object
KOAGULASI MENGGUNAKAN ALUM DAN PACl
Get PDFAlum and PACl Coagulation. Coagulation occurs by interaction of aluminum hydrolysis products with thecontaminant such as colloidal particles. It is necessary to consider the different aluminum species that may presentduring specific conditions, since the mechanism of turbidity removal is dependent upon them. PACl consists ofpreformed aluminum hydrolysis products, which are stable below pH 6 and less sensitive than in situ hydrolysisproduct, alum. The benefits of PACl relative to alum have been investigated as a function of pH and Al dosages.Specific conditions and aluminum species that exist during the certain mechanisms of coagulation are discussed.Results suggest that PACl is more effective than alum in lower pH range and high pH range, whereas alum is optimumin the neutral condition.Keywords: aluminum, charge neutralization, sweep coagulatio
PENGEMBANGAN ANALISIS STATIK PROTOTYPE KNUCKLE MOBIL KANCIL
Get PDFAnalysis of Kancil's Knuckle Prototype. The objective of this work is to execute strength analysis of knuckle, whichis made from FCD 50, by using static analysis on maximum loading. This maximum loading is obtained from front axleloading calculation on particular operating condition. That is, vehicle is braking while cornering in down hill. Fromprevious vehicle loading calculation, we get a number of loading values on different speed and deceleration. At the end,we get a value of speed and deceleration that guarantee the vehicle safety if it is braking while cornering in down hill.As comparison, loading calculation is executed too for same operating condition on level ground. This is because ofdifferent deceleration for each operating condition, 0,5g for operating condition on downhill and 0,2g on level ground.The result shows that maximum loading occurred when vehicle is operated on down hill is larger than on level ground.Study of static focused on quantitative description of loads that act on technical structure in equilibrium.Keywords: vehicle operating condition, maximum loading, working plane, free body diagram, moment and loadequilibrium principle
AKURASI WAVELENGHT–DISPERSIVE X-RAY FLOURESCENCE
Get PDFWavelenght-Dispersive X-Ray Flourescence Accuration. X-Fuorescence spectrometry is a method, which isincreasingly applied in the geochemical analysis. X-Fuorescence spectrometry is classified under two categories -WDXRF (wavelenght - dispersive X-ray fluorescence spectrometer) and EDXRF (energy-dispersive X - rayfluorescence spectrometer). WDXRF can be configured as a sequential spectrometer , a simultaneous spectrometer or ahibrid instrument, which combines the advantages of the simultaneous and sequential spectrometers into oneinstrument. Each instrument is different in some characteristics, and each has applications for which it is specificallysuited. In this investigation sequential spectrometer PW 1450 was used to analyze the major, minor and trace elementsin the samples. The standards used in calibrating the PW 1450 for the analysis of all samples are materials of knowncomposition (30 internatioanal standards and 66 standards from Institut für Mineralogie der Uni. Köln, Germany).Interelement and matrix effects are treated by matrix matching of samples and standards, dilution, preconcentration ofthe element of interest, and mathematic corrections during data analysis. The examination of two samples and thestatistic description using standard deviation and coefficient of variant show that the XFA is accurate enaugh for manyelements, especially for the major elements, but for Mg, Ca, K, Na, P, S, Co, Rb, Zn, Ni, Ba, Pb in comparison withAtomic Absorpsion Spectrometry (AAS), Flame Emission Spectrometer (FES), Inductively Coupled Plasma (ICP) andphotometer it is less sensitive. It is posible to devaluate the errors by using coefficient of variant and standarddeviation.Keywords: XFA, examination, samples, statistic, accurate
EFFECTS OF pH ON CALCIUM CARBONATE PRECIPITATION UNDER MAGNETIC FIELD
Get PDFMagnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale MagneticTreatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation inhigh and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. Theobservation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetizedsolutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In highsuper-saturated solution, magnetic field strengthens ion interactions, which reduce precipitation during circulationprocess. However, in low super-saturated CaCO3 solution, magnetic field weakens hydrate ion interaction whichindicated by decreasing of the conductivity of solution. It increases the precipitation of CaCO3 after the circulation ofmagnetization process has completed.Keywords: calcium carbonate precipitation, circulation flow, magnetic fiel
KARAKTERISTIK FISIK DAN PEMANFAATAN PANTAI KARST KABUPATEN GUNUNGKIDUL
Get PDFPhysical Characteristics and Utilization oft the Karst Beaches in Kabupaten Gunungkidul. Karsts beaches atGunungkidul Regency (Baron, Kukup, Sepanjang, Drini, Krakal, Ngandong, and Sundak), located in south of DaerahIstimewa Yogyakarta Province, have economic potential. Even they have similarity in geological condition (genesis andmorphological processes), but they have different physical characteristics. Based on result of observation environmenton morphological conditions and spatial analysis method, we found the proper utilization of the beaches.Keywords: karst beach, physical characteristics, spatial analysis method, utilization of the beache
PERAN 1 DAN 9 wt. % Zn DALAM PROSES PENGERASAN PRESIPITASI PADUAN ALUMINIUM AA319
Get PDFThe Role of 1 and 9 wt.% Zn in Precipitation Hardening of AA319 Aluminium. Aluminium alloys are widely used for automotive application due to its low density and high corrosion resistance. For economic reason, casting of automotive products always uses aluminium scrap as charging materials that may result in fluctuation of content of alloying element, such as Zn. This research studies the role of Zn in precipitation hardening of AA319 aluminium alloys. Hardness and tensile testing were conducted to study the mechanical properties of the alloys, while ageing response was followed by hardness measurements. Evolution of microstructures was observed by using optical microscope and SEM (scanning electron microscope) equipped with EDS (energy dispersive spectroscopy). Distribution of solute elements was detected by x-ray mapping and formation of nanoprecipitates was observed by using TEM (transmission electron microscope). Research results showed that addition of 1 and 9 wt. % Zn on AA310 alloys increases strength and hardness. Morphology transformation of Al-Fe-Mn-Si phase from chinese script into needle shape was detected, and may be due to dissolution of Zn in aluminium matrix that change the interfacial stress between the matrix and interdendritic phases. Addition of Zn also increased response of alloys to natural ageing but no significant change was detected for artificial ageing at 200 oC. Age hardening was contributed by the formation of θ’ (Al2Cu) nanoprecipitates. Zn was segregated on the periphery of Al2Cu phase.Keywords: AA319, Al2Cu, Al-Fe-Mn-Si, chinese script, precipitation hardenin
PENGOLAHAN LIMBAH LOGAM BERAT CHROMIUM (VI) DENGAN FOTOKATALIS TiO2
Get PDFPhotocatalytic Treatment of Heavy Metal Waste Cr(VI) with TiO2 Photocatalyst. The photocatalytic reduction of hexavalent chromium/Cr(VI) using TiO2 and copper-doped TiO2 as photocatalysts have been studied in stirred tank and circulating photoreactors. All photocatalysts were characterized with FTIR (Fourier Transform Infra Red), BET (Brunauer-Emmett-Teller), XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope). TiO2 Merck and Degussa P-25 are the commercial photocatalysts used to compare the photocatalytic activity of all the prepared catalysts. Blank test experiments as well as the effect of dopants, EDTA (ethylenediaminetetraacetic acid) and activated carbon addition were studied. Cr(VI) reduction on various pH and initial Cr(VI) concentration were also conducted. The results of the experiments showed that the addition of EDTA as a hole scavenger can increases the activity of all catalysts at about 10%. Rate of Cr(VI) photoreduction is more feasible at low pH and low initial Cr(VI) concentration. The addition of activated carbon (AC) increases the photocatalytic activity at about 5% due to the synergy effect between catalyst and AC. Pure TiO2 powder prepared from TiCl4 has the highest activity in reducing Cr(VI) with the conversion of 80% due to the high crystalline (anatase) and surface area. Photoreduction of Cr(VI) over TiO2 filmphotocatalyst in circulating photoreactor has not shown a significant result yet. Therefore it is needed to improvefurthermore the photoreactor system especially for the film type photocatalyst.Keyword: photoreduction, hexavalent chromium waste, TiO
STUDI KARAKTERISTIK FLUORESENSI CHLORELLA spp : PENGARUH pH TERHADAP PENGKULTURAN
Get PDFThe Study on Fluorescence Characteristics of Chlorella spp: pH Influence on Culture. Experiments for measuringthe fluorescence characteristics of Chlorella spp. by using high stability and high repetition rate nitrogen laser ofenergy 5 mJ with pulse duration of 5 ns have been carried out. The results show that for a cell concentration rangefrom 2,625 cells/ml up to 2,769,000 cells/ml, the fluorescence intensities at pada λ = 687 nm have a linear relationshipwith the cell concentration. It has been also found that for a 7 days old chlorella culture, the pH variation at thestarting culture influenced the cell concentration.Keywords: Chlorella spp., culture, fluorescence, pH, high stability nitrogen lase
ADOPTION OF VARIABLE RATE TECHNOLOGY
Get PDFSite Specific Management (SSM), which also variously referred to as Variable Rate Technology (VRT), is an emergingtechnology that enables producers to make more precise input application decisions based on soil and fieldcharacteristics. This study analyzes factors influencing the adoption of VRT for fertilizer application for cash grainproduction in Ohio. Results show that producer and field characteristics might influence the adoption decision onvarious SSM components differently. It also provides insight as to the sequence of adoption of SSM componenttechnologies and how this sequence might differ for producers of differing characteristics.Keywords: grid soil sampling, variable rate technology, yield monito