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Karakteristik Menara Pendingin dengan Bahan Isian Ijuk
Full text linkIn this study the characteristic of a water cooling tower by using the palm fibre as thepacking material have been investigated experimentally. The experiments were carried out in arectangle glass tower of 81 cm2 cross sectional area and 100 cm height. The packing used wasconstructed of 8 palm-fibre ropes (of about 0,6 cm diameter), zigzag vertically placed above thestainless steel support on the tower bottom. Its type has 28,3.10-4 kg weighs of rope every m3volume of the packing.The experimental results show that the increasing of the water inlet temperature and thepacking height cause the increasing of the tower characteristic. Mean while, the increasing ofthe water/air mass flow rate ratio causes the decreasing of the tower characteristic. The towercharacteristic is as a function of the investigated variables which expressed as:NTU = 3,35.10-3 (m w /m a )-0,995 (Z)0,5050 (T wi )1,1643with the relative error of 5,5%.This equation is valid for the range of variables, as m w /m a which is ranged from 4,46 to9,48, Z which is ranged from 30 to 90 cm, T wi which is ranged from 50 to 60 oC. The meaneffectiveness of the heat transfer were calculated to be 25,9%.Keywords: Cooling tower, characteristic, effectiveness, palm-fibre ropes
Nilai Kosmologi pada Tata Spasial Permukiman Desa Kapencar, Lereng Gunung Sindoro, Wonosobo
Full text linkThe Kapencar Village, as one of villages on the slope of Sumbing Mountain, hascosmological concept of spatial setting. The phenomenological research, was done by theresearcher as own instrument, explored for finding the spatial cosmological value in theKapencar villages. Some results of the research are:1) The Kapencar Village as the Glondongvilage, expresed the mon-copat concept, with the Kapencar village as the centre. 2) keblatwetan as a cosmological concept. Wetan orientation as a symbol of the start of living or thevery previous time of people living. Two cosmological concepts of spatial setting expresed theKapencar Village has the grand cosmologycal concept in people lining, there is keblat papatkalimo pancer (four orientations and the centre as the fifth oerintation).Kata kunci : Cosmology; the slope of the mountain settlement; spatial settin
Aplikasi Packet Diffusion Model untuk Menganalisis Pengaruh Fenomena Micromixing terhadap Jalannya Reaksi Kimia Paralel di dalam Reaktor Tangki reraduk Kontinyu dengan Aliran Umpan Terpisah
Full text linkThe effect of turbulent mixing on the course of two fast parallel competitive chemical reactions (netralization of sodium biborate snd iodide-iodate oxidation-reduction reactions) carried out in continuous stiwed tank reaktors have been studied theoretically, using PacketDiffusion Model, and experimentally to validate the theoretical predictions.System studied consists of flat bottom cylindrical tank 0.2 m in diameter. The height of liquid in the tank is also 0.2 m. The tank was equipped with Fan Turbine with diameter equal to I/3 tank diameter. Sulphuric acid solution (0.5 Il,Q was fed into the tank through 2 mm-diameter pipe, and the aquous solution containing 0.0909 M NaH2Boj, 0.0909 M H:Bo:, 0.0116667 M KI, and 0.0023333 M KIO3wasfed into the tank through I0 mm-diameter pipe. The rate of acid solution was varied 0,045, 0.068, and 0.09 liter/minute, while the rate of the other solution was varied I, 1.5, and 2 liter/minute (the rate variation coruespond to the mean residence time variation of 6, 4, and 3 minutes). The impeller rotation speedwas varied; 9,12, and I5 rps. The iodine concenftation in the tank influent was analyzed using spectrophotometer.The simulation works conclude that the selectivity of iodine decrease with increasing impeller rototion speed for the mean residence time of 3 and 4 minutes, while for the mean residence time of 6 minutes, the iodine selectivity increase with increasing impeller rotation speed. Increasing the mean residence time from 3 to 4 minutes will decrease the iodine selectivity, while increasing the mean residence time further to 6 minutes will increase the selectivity. The theoretical prediction using Packet Difusion Model agree fairly well with the experimental data. The experimental studies also showed that the feed position in the region of high turbulent intensity (impeller region) give lower iodine selectivity compaired to the selectivity in the region of lower turbulent intensity. The Packet Dffision Model cannot simulate the effect offeed position on the iodine selectivity.Keywords: Packet Diffusion Model, Micromixing, and Continuous Stirred Tank Reacto
Pengaruh Parameter Number Of Excitation (NEX) Terhadap SNR
Full text linkThis research aims to observe the influence of Number of Excitation (NEX) to bothparameters the Signal to Noise Ratio (SNR) and the scanning time when performing the MRneck . Some MR scan parameters (TR, TE, FOV, slice thickness, matrix, flip angle andbandwidth) are strictly under controlled. All SNR data, due to the 6 NEX variations (NEX 1 toNEX 6), are required by comparing the ROI’s intensity between the noise background and theareas of corpus and spinal cord on the images. The scan times are also recorded for each of theNEX variations being observed. In conclusion, increasing NEX values will simultaneously risethe SNR and the scanning time.Keywords : NEX, SNR, Image MRI, Scan tim
Peraturan Zonasi: Peran Dalam Pemanfaatan Ruang dan Pembangunan Kembali di Kawasan Rawan Bencana Kasus: Arkadelphia City, Arkansas USA
Full text linkEarthquake, tsunami and volcanic eruption are some of the various disasters that frequently hit in Indonesia. These disasters impact damage from small to large. These disasters also have a major impact on the balance of community lifes who are victims. Various efforts of reconstruction, rehabilitation and reconstruction are undertaken by governments, communities and various stakeholders. To succeed as expected, these efforts should be based an a spatial plan which is suitable and comprehensive. The spatial planning in disaster prone areas is indispensable in dealing with disasters before, during and after a disaster. Formulation and implementation of spatial plans are turned to face many problems such as limited and the loss of data due to disasters, as well as social and cultural conditions in disaster prone areas. To streamline the implementation of spatial plans and land use control need zoning regulation as a land use control instrument. Therefore, it is necessary to study the role of zoning regulation in the utilization of space and rebuilding in disaster areas prone.This study used a descriptive approach with literature sources. The results show that: (1) The Making of spatial plan on the basis of disaster mitigation in disaster prone areas is indispensable in dealing with disasters, before, during and after a disaster and should be complemented with zoning regulations, (2) The making of spatial plan and zoning regulations in the region after the disaster requires a special approach by modifying the normal procedure, and (3) zoning regulation as a land use control instrument control instrument guides the implementation of various activities related to disaster mitigation and need to be adjusted to the social, economic, cultural and characteristics of each disaster prone areas.Keywords : spatial plan, zoning regulation, disaster prone areas, disaster mitigation
Ontologi Sistem Penilaian E-Learning Berbasis Kompetensi
Full text linkAutomation grading on e-Learning assessment helps educators in assessing the results of the exam. In a previous research, automation grading vaue jus in the form of numbers, not performed a review the achievement of competency standards. In this research we developed assessment system ontology design fo e-learning base competence. This propose ontology design models the relation between matter and competence then made the rule for the calculation of achievement students against each competency and make recommendations to the student passing the exam. From the test results with the protege show that ontology design can grade the assessment and give recommendations to the student passing the exam, in accordance with the rules made.Keywords : Ontology, assessment e-Learning, Automation grading
Performa Mesin Sepeda Motor Empat Langkah Berbahan Bakar Premium dan Pertamax
Full text link The Republic of Indonesian government proposes the owners of private vehicle in order to use pertamax as fuel. Premium will be consumpted specially for the public transportation. Therefore it is required research how the effect of fuel used to the engine performance. This research has used a matic motor cycle engine as testing material. This vehicle is used because matic vehicle are large applicated as private transportation. Data which are required as performance of the engine, involve power and torsion, rate of fuel consumption, temperature of cylinder head cover and emission of the axhausted gas. Based on the anaysis of the data, can be concluded that type of the fuel affects to the engine which consumpted pertamax are higher than engine which consumpted premium. Rate of premium consumption is larger than rate of pertamax consumptionKeywords : engine performance, oil fuel, emision
Ekstraksi Ciri dan Identifikasi Citra Otak MRI Berbasis Eigenbrain Image
Full text linkIn this research, we exctract and identify MRI brain images based on eigbrain image. MRI barain images are used to be input for feature exctraction and identitication. Feature exctraction is done by using the eigbrain image. For all reference image, we find image mean and eigbrain image, and the results are stored. If there is test image, we will find the nearest distance of eigenbrain between test image and reference images. The feature extraction is used to identify the image is whether the normal brain image or the brain image with tumor.The results show that the method successfully classifies MRI images into tree clusters: normal, glioma, and metastase. The input test images can be identified accurately 100% for image sizes from 256 x 256 pixels to 64 x 64 pixels.Keywords : feature extraction, image identification, MRI medical image, eigenbrain image
Komparasi Karakteristik Menara Pendingin Menggunakan Beberapa Tipe Susunan Pipa-pipa sebagai Pendistribusi Cairan
Full text link The aims of the experiments are to characterize of the cooling tower by using the bank of the pipes as the fluid distributor. The cooling tower is constructed by rectangle of glasses which it has 9 cm x 9 cm in cross section and 100 cm in height. The fluid distributors are constructed by pipes in 5/8 inch of nominal diameter. There were five types of the packing namely the fluid distributor without baffle, fluid distributor with one baffle, the fuid distributor with two baffles, the fluid distributor with there baffles and the fluid distributor with four baffles. The experiment have been done by flowing the hot water from the top of cooling tower through the fuid distributor, on the other hand, the air cooler is flown above through the fluid distributor opposite to the water flow direction. This process makes the exchanging of the heat between air and water on the fluid distributor. The variables varied in this experiments are the inlet water temperature, Twi (45, 50, 55 and 60 °C), the height of fluid distributor, Z (30.5, 61 and 91.5 mm), the ratio of water/air mass flow, mw/ma (3.624, 5.888 and 7.700) and the number of baffle (without baffle, one baffle, two baffles, three baffles and four baffles). The experimental results show that in the ratio of water/air mass flow rate which is lower, the increasing of the numbers baffle cause the decreasing of characteristic. Mean while, in the ratio of water/air mass flow rate which is higer, the increasing of the numbers of baffle cause the increasing of the characteristic. The cooling tower without the fluid distributor has the average characteristic is 13.4% and the average effectiveness is 16.2%. For the cooling tower with the fluid distributor has the average characteristic is 31.5% and the average effectiveness is 25.0%. Keywords : Cooing tower, characteristic, fluid distributor
Dinamika Pemanfaatan Lahan Kampung Bersejarah 'Luar Batang' - Jakarta Utara
Full text linkThe dynamic of land utilization is related to changes of land function. In this contect, the morphological study is impemented to uncover the changes in land functions in Kampung Luar Batang, Nort Jakarta, Indonesia. Kampung Luar Batang is a historical Kampung which was estabished by VOC in Batavia under the influence of existence of a Moslem missionary, Al-Habib Husein bin Abubakar Allaydrus, and accelerated by the its strategic geographical location close to urban economic centers, Historically, Luar Batang has been a place for laborers' settlement, VOC defense port, port of transit for migrants, pilgrimage center and rental dwelling that is surrounded by illegal housing. Each function was not chronologically appeared, but developed in multi-layered manner.In fact the historical meanings of Luar Batang were not obtained through in depth literature study, since the availability of references about the kampung is very limited. This study is an effort to uncover the physical elements of the kampung from historical perspective, based on the maps documentatin and empirical study. The graphical abstraction model presented at this paper is an attempt to clarify the dynamic of land utilization.Keywords : Morphology, Kampung bersejarah, Luar Batang