MAKARA Journal of Technology
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PRODUCTION OF LOVASTATIN AND SULOCHRIN BY Aspergillus terreus USING SOLID STATE FERMENTATION
No full textLovastatin is an anti-cholesterol agent that was produced by Aspergillus terreus using solid state fermentation (SSF). During this fermentation process, sulochrin is also produced as an unwanted co-metabolite. However, our previous result showed that sulochrin had potential as antidiabetes because it is an inhibitor agent of α-glucosidase. In this paper, we reported our observation on lovastatin and sulochrin production pattern in relation with inhibitor α-glucosidase activity during eleven days fermentation of A. terreus koji (SSF) ethyl acetate extract. Koji obtained from solid state fermentation with rice as the substrate and incubated at room temperature, sample is taken daily for eleven day (D-1 to D-11). Lovastatin and sulochrin production was measured by Liquid Chromatography- Mass Spectrometer based on their molecular weight m/z 404.5 and 332.3 respectively. The inibitory activity is measured by inhibition model of koji extract against α-glucosidase (EC 3.2.1.20) from Saccharomyces cereviceae. The results show that lovastatin production was started on the day 2 (0.04 mg/g) and achieving the optimal production on day 7 (11.46 mg/g), while sulochrin production was started on day 4 (0.60 mg/g) and keep produced until the end of fermentation period at Day 11 (3.11 mg/g). Koji extract was started to show inhibitory to α-glucosidase activity on Day 5 (IC50= 23.34 μg/mL) and keep showed activity until Day 11 (IC50=3.33 μg/mL). These results suggest that inhibitory activity of koji extract to α-glucosidase activity have relation with sulochrin biosynthesis production.Keywords: α-glucosidase inhibitor, Aspergillus terreus, lovastatin, SSF, sulochri
PENGARUH UNSUR – UNSUR KIMIA KOROSIF TERHADAP LAJU KOROSI TULANGAN BETON : II. DI DALAM LUMPUR RAWA
Get PDFA polluted environment will influence the building age. The objective of this research was to find out the influence ofcorrosive chemicals within the sludge swamp area with the corrosion rate of steel concrete. Corrosion in steel concreteusually occur in acid area which contain of SO42-, Cl- and NO3-. The research treatment used by emerging ST 37 andST 60 within 60 days in 'polluted' sludge swamp area. Three variation of 'polluted' swamp sludge were made by increasing the concentration a corrosive unsure up to 1X, 5X and 10X. The corrosion rate measured by using an Immersion Method. The result of Immersion test showed that sulphate had a greatest influence to corrosion rate of ST 37 and ST 60 and followed by chloride and nitrate. Corrosion rate value for ST 37 was 17.58 mpy and for ST 60 was 12.47 mpy.Keywords :Corrosions rate, steel concrete, sludge swam
PENGARUH SUHU PEMANASAN DAN WAKTU TAHAN TERHADAP KARAKTERISASI MATERIAL KOMPOSIT LOGAM AL/SiC HASIL INFILTRASI TANPA TEKANAN
Get PDFEffect of Firing Temperature and Holding Time on Characterization of Al/SiC Metal Matrix CompositesProduced by Pressureless Infiltration. The production of Al-SiC metal matrix composite can be carried out bypressureless metal infiltration processs (PRIMEX). The experiment was conducted using aluminium AC2B ingot as amatrix and 50%Vf SiC powder as a reinforcement which is mixed with 10% Mg powder for wetting agent. Thevariables of this experiment are holding time and firing temperature to investigate the effect of these conditions onmechanical properties of Al-SiC metal matrix composites. Holding time was conducted for 2,5,8,10,12 hours and firingtemperatures was 750, 800, 900, 1000, 1100°C respectively.. The composites produced are analysed both mechanicalproperties and metalography such as densities, porosities, hardness, as well as wear rate. The results showed that thelonger holding time and increasing firing temperature will increase mechanical properties of Al-SiC metal matrixcomposites, and it is found that the optimum mechanical properties at 1000°C for 10 hour.Keywords: Al-SiC metal matrix composite, pressureless infiltration
PARTICLE FILTER WITH BINARY GAUSSIAN WEIGHTING AND SUPPORT VECTOR MACHINE FOR HUMAN POSE INTERPRETATION
Get PDFHuman pose interpretation using Particle filter with Binary Gaussian Weighting and Support Vector Machine isproposed. In the proposed system, Particle filter is used to track human object, then this human object is skeletonizedusing thinning algorithm and classified using Support Vector Machine. The classification is to identify human pose,whether a normal or abnormal behavior. Here Particle filter is modified through weight calculation using Gaussiandistribution to reduce the computational time. The modified particle filter consists of four main phases. First, particlesare generated to predict target’s location. Second, weight of certain particles is calculated and these particles are used tobuild Gaussian distribution. Third, weight of all particles is calculated based on Gaussian distribution. Fourth, updateparticles based on each weight. The modified particle filter could reduce computational time of object tracking sincethis method does not have to calculate particle’s weight one by one. To calculate weight, the proposed method buildsGaussian distribution and calculates particle’s weight using this distribution. Through experiment using video datataken in front of cashier of convenient store, the proposed method reduced computational time in tracking process until68.34% in average compare to the conventional one, meanwhile the accuracy of tracking with this new method iscomparable with particle filter method i.e. 90.3%. Combination particle filter with binary Gaussian weighting andsupport vector machine is promising for advanced early crime scene investigation.Keywords: particle filter, prediction, skeletonization, support vector machine, updat
ANALISIS ERGONOMI SEPEDA UI DENGAN METODE POSTURE EVALUATION INDEX (PEI) DALAM VIRTUAL ENVIRONMENT
Get PDFErgonomic Analysis of UI Bicycle Using Posture Evaluation Index (PEI) Method in Virtual Environment. Thisresearch was conducted to study ergonomic aspect from University of Indonesia bicycle in virtual environment.Software Jack 6.0 was used to analyze it. PEI was used as approach that integrated the results of three methods: LowerBack Analysis, Ovako Working Posture Analysis, and Rapid Upper Limb Assessment. The research objective is toevaluate existing design of University of Indonesia bicycle and to determine the most ergonomic redesign whichconcern with handlebar height and saddle height modification. The result showed that the most ergonomic design ofUniversity of Indonesia bicycle is the one with the highest handlebar height (22 cm) and the lowest saddle height (11cm).Keywords: ergonomics, LBA, OWAS, RULA, virtual environmen
POTENSI PEMBANGKIT DAYA TERMOELEKTRIK UNTUK KENDARAAN HIBRID
Get PDFPotency of Thermoelectric Generator for Hybrid Vehicle. Thermoelectric Generator (TEG) has been known aselectricity generation for many years. If the temperature difference occurred between two difference semi conductormaterials, the current will flow in the material and produced difference voltage. This principle is known as Seebeckeffect that is the opposite of Peltier effect Thermoelectric Cooling (TEC). This research was conducted to test thepotential of electric source from twelve peltier modules. Then, these thermoelectric generators were applied in hybridcar by using waste heat from the combustion engine. The experiment has been conducted with variations of peltiermodule arrangements (series and parallels) and heater as heat source for the thermoelectric generator, with variations ofheater voltage input (110V and 220V) applied. The experimental result showed that twelve of peltier modules arrangedin series and heater voltage of 220V generated power output of 8.11 Watts with average temperature difference of42.82°C. This result shows that TEG has a bright prospect as alternative electric source.Keywords: peltier element, seebeck effect, thermoelectric generato
SEGMENTASI CITRA SECARA SEMI-OTOMATIS UNTUK VISUALISASI VOLUMETRIK CITRA CT-SCAN PELVIS
Get PDFSemi-Automatic Image Segmentation for Volumetric Visualization of Pelvis CT Scan-Images. The currentdevelopment of computerized tomography (CT) has enable us to obtain cross sectional image using multi slicingtechniques in an order of few seconds. The obtained images represent several tissue structures on cross section slicebeing imaged. One challenge to help diagnosis using CT images is extracting an anatomic structure of interest using amethod of image segmentation and volumetric visualization with the assistance of computers. In case of volumetricvisualization of pelvis bones extracted from multi-slice CT images, whole images which are containing part of pelvisbone structures must be segmented. In this research, an image segmentation technique based on active contour isimplemented for semi-automatic multi slice image segmentation. Image segmentation steps are initialized with a definemodel of 2D curve on the first slice image manually. Next, its model curve is deformed to reach the final result of 2Dcurve that fits to boundary edges of pelvis bone image. The final result of 2D curve on previous slice image was used asan initialization model of 2D curve on the next slice images. This process will continue until the final slice image. Thissegmentation method was compared with the segmentation method based on threshold from homogenous intensitydistribution and manual segmentation method. Quantitative analysis from the results of segmentation on each slice andqualitative analysis on the representation of volumetric visualization are performed in this research.Keywords: active contour, image segmentation, multi slice CT images, pelvis bones, volumetric visualizatio
ABSORBSI CO2 DARI CAMPURANNYA DENGAN CH4 ATAU N2 MELALUI KONTAKTOR MEMBRAN SERAT BERONGGA MENGGUNAKAN PELARUT AIR
Get PDFCO2 Absorption from Its Mixture with CH4 or N2 through Hollow Fiber Membrane Contactor using Water asSolvent. Hollow fiber membrane contactors have been widely used as gas-liquid contactors recently such as in the CO2absorption process from gas stream. This research aims to evaluate the effectiveness of hollow fiber membranecontactor to absorb CO2 from its mixture with CH4 or N2 using water through mass transfer and hydrodynamic tests.There are 3 membrane modules used in this research with shell diameter of 1.9 cm, length of 40 cm, outer fiberdiameter of 2.7 mm and fiber number in the contactors of 10, 15 and 20. Liquid flow rates in the hollow fiber membranecontactors are varied in this research. Research results show that mass transfer coefficients in the membrane contactorincrease with increasing liquid flow rate and decrease with increasing fiber number in the contactor. Flux of CO2 intowater can achieve 1.4x10-9 mol CO2 /m2.s and mass transfer coefficients can achieve 1.23 x 10-7 m/s. Meanwhile,hydrodynamic test results show that water pressure drop in the membrane contactors increase with increasing fibernumber in the contactors.Keywords: hollow fiber, contactor, mass transfe
PENGGUNAAN PROSESOR DSP SEBAGAI PENGGANTI KOMPONEN RANGKAIAN CDMA
Get PDFThis research develops the software of DSP Processor type TMS320C54X for the CDMA circuitry. This research applytwo algorithms namely Mathematic Algorithm and table lookup Algorithm. From both algorithms, the research examinewhat algorithm have the fasted processing time and the smallest memory occupation. From the examination results theMathematic Algorithm have 20.62 milliseconds processing time and the Table lookup algorithm have 14.08 millisecondsprocessing time. The Table lookup algorithm have the fastest processing time because the Matematic algorithm need therounding process of the fi gure. Eventhough such processing time is not exceed from the 125 millisecond of delay time, inreal condition, the total processing time are include the error correction processing time and voice compression processingtime such as ADPCM or QCELP voice compression techniques.Keywords: DSP, digital signal processing, CDM
SIFAT SELF-IGNITION PADA GAMBUT, SABUT KELAPA SAWIT DAN KAYU
Get PDFSelf-ignition properties of peat, palm shell fibre and woods. Forest fire is one of the greatest environmental problems faced by Indonesia. Forest fires have destroyed million hectares of forest and land which cause economic loss, social problems including smoke related diseases and environmental disaster with long time consequences. The exothermic reactions of forest fuels that lead to fire can be initiated by a piloted flame and low-temperature oxidation mechanism. This paper presents the results of low temperature oxidation studies using forests fuel samples i.e. palm shell fibre, peat, woods and low-rank coal. The measured values of the critical oven temperatures and the kinetic oxidation parameters are used to analyze the intrinsic properties of the samples to self-ignite. Thermal runaway reactions leading to ignition are indicated for all forest fuels tested. This reaction is affected by various factors including oven temperature, moisture content, chemical and physical properties as well as basket sizes. Attempt to extrapolate the results of these laboratoryscaled experiments for real fires still require further tests and assessments.Keywords: self-ignition, critical oven temperature, kinetic oxidation parameter, peat, palm shell fibe