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IPTEK The Journal for Technology and Science
ISSN : 08534098     EISSN : 20882033     DOI : -
Core Subject : Science,
IPTEK The Journal for Technology and Science (eISSN: 2088-2033; Print ISSN:0853-4098), is an academic journal on the issued related to natural science and technology. The journal initially published four issues every year, i.e. February, May, August, and November. From 2014, IPTEK the Journal for Technology and Science publish three times a year, they are in April, August and December in online version.
Arjuna Subject : -
Articles 345 Documents
Mixing Rule of Sanches-Lacombe Equation of State for Prediction of Solvent Solubility in Polymer Solution Wibawa, Gede
IPTEK The Journal for Technology and Science Vol 19, No 3 (2008)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v19i3.147

Abstract

In this work, mixing rule of Sanches-Lacombe equation of state (SL-EoS) was developed for estimating vapor-liquid equilibria of solvent-polymer systems or solubility of solvent in polymer solutions. The model was derived by matching excess Gibbs energy of Sanches-Lacombe equation of state and that of group contribution model at zero pressure. Present model can be applied to wide range of pressure. In addition, this model covers systems with various molecular interactions, since functional group interaction parameters of UNIFAC-FV and UNIFAC-ZM models have been available for various groups.
Evaluating Error of Temporal Disaggregation from Daily into Hourly Rainfall using Heytos Model at Sampean Catchments Area Hidayah, Entin; Anwar, Nadjadji; Edijatno, Edijatno; Iriawan, Nur
IPTEK The Journal for Technology and Science Vol 21, No 1 (2010)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v21i1.25

Abstract

Developing a rainfall-runoff model sufficient to flood prediction hourly rainfall data. Lack of automatic rain gauge for high resolution rainfall in catchment area can be an obstacle for the modeling. Otherwise, the manual rain gauges may spread on all of catchments areas, providing daily rainfall. Daily rainfall disaggregation to hourly rainfall is an innovation to get higher temporal resolution of the rainfall. This paper attempts to evaluate the implementation of rainfall disaggregation model in Sampean Catchments Area using Heytos. The proposed parameter optimation use Moment Performance model that tested by calibrating it with available hourly data. The results of model indicated that only data within five months had good performance. The estimation result showed that relative error total of January, February, August, November, and December was less than one. In case of March, April, May, June, July, September, and October the model could not result respectively to generate model.
An Investigation into the Application of Maintenance Management Concept Based on Reliability Centered Maintenance of Tni-Al Fleet (Case Study of Corvette / Parchim Class) D.K., Yanif; T.D., Iman
IPTEK The Journal for Technology and Science Vol 18, No 1 (2007)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v18i1.180

Abstract

The majority of TNI-AL war-ships, particularly of parchim class, are old and have been used for more than twenty years. It can be said, intuitively, that rate of degradation of diesel engine system lies in the wear-out period of a bathtub curve. The present paper is aimed to obtain and prove degradation pattern rate and level of risk from diesel engine system installed in KRI fleet of parchim class. Function of degradation rate of each diesel engine system is obtained from the most suitable distribution represent failure mode. Whilst, level of risk is determine with risk matrix. Weibull++ 4, a reliability software, was used to obtain parameters fit to each distribution.
Analysis of Dynamic Inertia Forces at Main Bearing of Ship Reciprocating Engines Zubaydi, A. Zubaydi; Ariana, M. Ariana; Baliwangi, L. Baliwangi; Masroeri, A. A. Masroeri; Louhenapessy, F. Louhenapessy; Tukan, M. Tukan; Taribuka, S. M. Taribuka
IPTEK The Journal for Technology and Science Vol 21, No 4 (2010)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v21i4.50

Abstract

During operation, a ship reciprocating engine will vibrate due to the force resulting from the cycle movement of the dynamic components. Soon or later, the vibration will cause wear of engine components. Therefore, the cause of vibration should be early identified so that the propagation of wear can be anticipated. The study modeled the ship reciprocating engine as a two stroke engine, and analyzed one of the causes of the engine vibration, i.e. the force acting on main bearing, using a numerical simulation. An experimental study was also carried out for measuring the acceleration of vibration response due to the numerical dynamic inertia force. The results showed that the dynamic inertia force acting on the main bearing is the main cause of the vibration of engine.
Hydrodynamic Forces acting on Two Flexible Free-hanging Cantilevers in Tandem Configurations due to Cross-flows Prastianto, Prastianto
IPTEK The Journal for Technology and Science Vol 20, No 4 (2009)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v20i4.85

Abstract

The experimental study has been performed on two flexible free-hanging circular cantilevers in tandem configurations subjected to uniform cross-flows. The experiment was intended to investigate the time-dependent forces characteristics acting on the cylinders due to VortexInduced Vibration (VIV) phenomenon. The tests cylinders have free bottom-end conditions and can freely oscillate. The motions of the cylinders are evaluated as a bidirectional motion, in-line and transverse to the flow. Each cylinder has a length-to-diameter ratio of 34.4 with a low mass ratio of about 1.24. Based on cylinder’s diameter and free-stream flow velocities, the Reynolds number varied from 10,800 to 37,800. For examining Wake Induced Vibration (WIV) on the induced forces characteristics, five different gaps between the cylinders were employed. New various findings indicated that the dynamics of the present two free-hanging cantilever cylinders in tandem configurations are unique and definitely different to those other tandem configurations of either, two stationary cylinders or a transverse-only motion downstream cylinder lies behind a stationary upstream one.
Vibration Energy Harvesting on Vehicle Suspension Using Rotary and Linear Electromagnetic Generator Sultoni, Arif Indro; Sutantra, I.N.; Pramono, Agus S.
IPTEK The Journal for Technology and Science Vol 24, No 1 (2013)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v24i1.136

Abstract

In this paper, we discuss comparation of vehicle vibration energy harvesting between rotary and linear electromagnetic generator. We construct the two model of energy harvester mechanism and then analyze both of energy absorbtion and vehicle comfortability. Furthermore, we analyze both of energy absorbtion and vehicle comfortability. Vehicle is modeled as quarter car. Rotarty generator harvests 2.5 x 10-4 Watt. The other hand, linear generator has viscous characteristic and capable to generates 90 Watts with 12 Volt power supply for 0.03 m amplitude of bumpy road input. Linear generator reduces oscillation with 1.2 sec settling time. It is more comfort than the angular which has 3 sec in settling time. With unnevenees road input, mean power of this generator is 64 Watt.
Sensitive Magnetic Field Sensor Based on Compensated Double Pick Up Coil Purnama, Budi; Suharyana, Suharyana; Sutomo, Artono Dwijo
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.16

Abstract

Sensitive magnetic field sensor based on compensated double pick up coil has been developed. In order to confirm sensitifity of modified design, experiment carried out in two steps. Firstly, sensitify of conventional design is clarified. Here pick up coil as an active sensor and solenoid as an exitation coil is separately made. Secondly, modified sensor of integrated configuration is developed. Here for both active flux gate sensor and the exitation coil is made in same one core magnetic. Ferrite and standar foil soft magnetic is utilized in this experiment. In attention, frequency of 50 Hz is used for the whole experimens. A result showed that sensitvity of the integrated configuration sensor is much larger than conventional one. Then, power consume of the integrated flux gate sensor is much lower than conventional. Finally, a range measurement of the integrated configuration sensor can be realized less than 20 T which potential may perhaps sense a change of natural local magnetic field.
Structural and Transport Properties of Hybrid Organic Inorganic Silica Membranes Haryadi, Haryadi
IPTEK The Journal for Technology and Science Vol 18, No 2 (2007)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v18i2.171

Abstract

The series of hybrid organic-inorganic silica materials have been prepared by introducing organic ligands materials based on sol-gel processing of alkoxysilanes for potential applications in membrane design for pervaporation. The materials were characterized using structural and dynamic techniques to gain information about the formation of micro- and mesoporous silicates. The dynamic interaction within silica matrices were investigated using FTIR, Raman Spectroscopy, Solid State NMR Spectroscopy, Physisorption and SEM. The transport properties of the hybrid materials were observed by monitoring the diffusion behavior of water and several selected solvents using Pulsed Field Gradient NMR. The self-diffusion of water and organic solvents in the hybrid silica materials were two to three orders of magnitude smaller than in the liquid bulk suggesting restricted diffusion at the pore surface. The effect of surface polarity also contributed to water and solvents diffusivities. The temperature dependence of diffusion was useful to derive the activation energy whereas the dependence on NMR observation time provided information on both tortuosity and pore connectivity of the hybrid silica materials. These materials have potential uses in gas and liquid separation such as pervaporation.
Kinetics of Hg and Pb Removal in Aqueous Solution Using Coal Fly Ash Adsorbent Eko Prasetyo Kuncoro; Mochammad Zakki Fahmi
IPTEK The Journal for Technology and Science Vol 25, No 3 (2014)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v25i3.480

Abstract

Water pollution caused by heavy metals is a serious problem to environment. Hg and Pb are heavy metals having high toxicity level. Heavy metals treatment is necessary before releasing them to environment. The use of adsorption method is interesting because of its relatively simple operation. The development of adsorption is oriented to the use of industrial waste such as coal fly ash. The objective of this research is to investigate the kinetics aspect of Hg and Pb adsorption using coal fly ash. A series of a Hg and Pb adsorption experiment using coal fly ash with time variation was carried out. The results were plotted to pseudo first order kinetic and pseudo second order kinetic model. The conclusion obtained was that Hg and Pb adsorption kinetics followed pseudo second order kinetic model
The Effect of Marine Fish Biomass Stock Reduction to Fishers Revenue (A Case Study of Sardinella Lemuru Fisheries on Bali Strait) Ratna Purwaningsih; Sjarief Widjaja; Sri Gunani Partiwi
IPTEK The Journal for Technology and Science Vol 22, No 3 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i3.73

Abstract

Stock assessment studies indicate that Sardinela Lemuru fisheries of Bali strait have been overfishing. This research attempts to (1) Identify the effect of biomass stock reduction to fishers revenue per trip, (2) Analyze the economic feasibility study for purse seine of Muncar, Banyuwangi. System Dynamic approach is used for simulation modeling. Simulation output shows a strong correlation between fish stock reduction and fisher revenue. The growth of fishing effort per year results on the reduction of catch per unit effort and total catch per year. Feasibility study concludes that purse seine (30 GT) which operates 120 trips per year is no longer a profitable business since 2020.