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All Journal Jurnal Energi Dan Manufaktur Reaktor SAINSTECH: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Koswara Koswara
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Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

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Penambahan Cil Pada Desain Sistem Saluran (gating system) Low Pressure Die Casting (LPDC) Untuk Mereduksi Kebocoran Akibat Hole Ada Produk Kran Hotel Dengan Simulasi Procast V2008 Muhammad Fitrullah; Koswara Koswara; Ricky Parmonangan
Jurnal Energi Dan Manufaktur Vol 7 No 1 (2014): April 2014
Publisher : Department of Mechanical Engineering, University of Udayana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (640.381 KB)

Abstract

Abstrak : Kuningan merupakan paduan logam yang memiliki performa estetis yang tinggi sehinggabanyak dipakai untuk produk kran. Performa estetis ini menjadikan kran dari kuningan banyakdipakai di dunia perhotelan. Secara umum, produk kran dihasilkan melalui proses casting(pengecoran) yang dirancang melalui sejumlah simulasi guna menghasilkan produk dengankualitas tinggi. Pengecoran logam kuningan sering digunakan metode Low Pressure DieCasting (LPDC). Simulasi pengecoran adalah metode yang sangat baik untuk dapat melihatpenuangan logam cair pada cetakan, proses solidifikasi dan pendinginan, dan memprediksiletak cacat yang akan terjadi seperti shrinkage, porositas, inklusi, hole. Pada industripengecoran kran, banyak cacat pada produk hasil coran, yaitu: 8% produk bad, yang artinyaproduk tidak bisa digunakan atau harus di lebur ulang dan 24% produk modifikasi dengan cacatyang paling sering terjadi adalah “bocor” dan “hole” yang artinya produk mendapatkanperlakuan khusus karena terjadi cacat tetapi masih bisa ditanggulangi. Hal ini sangat merugikanperusahaan baik dalam biaya produksi yang menjadi meningkat dan waktu produksi yangsemakin lama. Penelitian ini bertujuan untuk menganalisa arah pembekuan logam yang terjadipada proses low pressure die casting pada produk kran dan membuat desain sistem saluranlow pressure die casting untuk produk kran untuk mereduksi kebocoran akibat cacat hole.Metode yang digunakan dengan finite element method (FEM). Melakukan observasi proses lowpressure die casting untuk produk kran, membuat desain sistem saluran yang sudah dimilikiPT.X dengan menggunakan solidwork 2010 dan mensimulasi dengan procast v2008. Hasilsimulasi diamati sehingga diketahui letak cacat yang terjadi dan membuat desain yang baruagar didapat hasil yang maksimal. Hasil simulasi yang diamati ada daerah yang mengalamipremature solidification sehingga dapat menghasilkan hole dan poros. Penambahan cil padasistem saluran menjadi solusi yang tepat untuk meminimalisasi cacat hole dan porositas yangada. Daerah yang mengalami premature solidification dikenakan suhu yang lebih rendah darilogam kuningan cair sehingga daerah tersebut lebih cepat membeku dan terjadi pembekuanyang terarah.Kata kunci: Pengecoran, LPDC, hole, poros, premature solidification, pembekuan.Abstract : Brass is an alloy that has a high aesthetic value that is widely used for product faucets. Thismakes the aesthetic value of brass faucet widely used in the world of hospitality. In general,faucet products produced through the casting process through a number of simulationsdesigned to produce high quality products. Brass foundry frequently used method of LowPressure Die Casting (LPDC).Casting simulation is an excellent method to be able to seepouring molten metal in the mold, solidification and cooling process, and predicts the location ofdefects that will occur such as shrinkage, porosity, inclusions, holes. In the foundry industryfaucets, many defects in castings products, namely: 8% bad product, which means thatproducts can not be used or should be recycled and 24% Melting modification products with themost common defect is "leaking" and "hole" that means products get special treatment becauseof a disability but can still be addressed.This is very detrimental to the company due toincreased production costs and production time is longer. This study aims to analyze thedirection of the metal freezing that occurs in low pressure die casting process on the faucet andmake product design duct system for low pressure die casting product faucets to reduceleakage due to defective hole. The method used by the finite element method (FEM).Observation of low pressure die casting process for product faucets, making the design of theduct system already owned PT.X using solidwork 2010 and simulate with ProCast v2008. Thesimulation results were observed in order to know the location of the defect and create newdesigns in order to obtain maximum results. The simulation results are observed there are areasexperiencing premature solidification so as to produce a hole and shaft. Addition chill onchannel system be the perfect solution to minimize defects and porosity existing hole. Areas experiencing premature solidification incur lower temperature of molten brass metal so that thearea freezes faster and directional freezing occurs.Keywords: Casting, LPDC, hole, shaft, premature solidification, freezing.
The moving-slab Heating in the furnace for various production plans Istadi Istadi; Y. Bindar; Koswara Koswara
Reaktor Volume 6 No. 1 Juni 2002
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4978.075 KB) | DOI: 10.14710/reaktor.6.1.1-7

Abstract

The reheating furnace in occasional production time has to be charged with slabs having fifferent sizes in length, ridth and thickness. This production plan was put due to economical and productivity consideration. Moreover in the future development, the slab grade might be improved to hight grades. It is our expectation that the furnace can be fire for different production plans above. The strategy for firing the burners from zone to zone has to  be determined precisely to meet the designed heating curves for the various slab. A suggest to guide in the formulations of the furnace firing strategy was developed in this work. This suggestion is based on three-dimentional mathematical model for heated slab in the furnace. This mathematical model was coded  for the computational simulation. The  code was able to simulate  furnacthree-dimentional effect of fuenace operational parameters and variety of slab length group. The result reasonably represent the slab-heating curve for different operational parameters. Unsymmetrical firing practices can be shown their effect to the 3D temperature distribution of the slab. Keywords : 3Dtemperature distribution, reheating furnace, slab heating, slab length group
Analisis Critical Path Model yang Digunakan Dalam Manajemen Proyek dan Kontribusinya Terhadap Manajemen Mutu ISO 9001 Di Perusahaan Konstruksi Di INDONESIA Gugum Gumilar; Koswara Koswara
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 33 No 2 (2023): Sainstech: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v33i2.1581

Abstract

ABSTRACT Critical Path Model (CPM) has been widely used in construction project management as an effective and efficient tool for planning and managing project schedules. This study aims to analyze the contribution of CPM to quality management geothermal project at Lumut Balai, especially in the context of ISO 9001. By reviewing existing literature and case studies, this study explores how CPM can increase the effectiveness and efficiency of ISO 9001 quality management. From the analysis obtained 12 critical paths on the disciplines of Mist Eliminator, Piping, Mechanical, and Painting & Insulation. The results of this study show that the use of CPM can reduce the duration to 604 days compared to the initial schedule of 825 days. CPM can play a significant role in improving quality management in construction companies by providing clear and accurate project schedules, reducing delays, and improving overall project performance. In addition, integration of CPM with quality management tools can enhance overall quality management system and increase chance of project success. The conclusion of this study is CPM has great potential to assist construction companies in increasing the effectiveness and efficiency of ISO 9001 quality management. Construction companies in Indonesia should adopt CPM as a project management tool to ensure project success and meet ISO 9001 quality standards. This study provides insights positive about the future of CPM in construction project management and open opportunities for further research in this field. Keywords: CPM, critical path, quali
Penghematan Energi Pada Sistim Pendingin Bangunan Hotel “The Dharmawangsa Wishnuwardhana Jam; Koswara Koswara; Nofirman Nofirma
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 33 No 3 (2023): Sainstech: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v33i3.1661

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Abstract : Conservation of natural resources, one of which is electrical energy, is mostly generated from limited natural resources such as coal, petroleum, and natural gas. Electrical energy is crucial in the natural hospitality/ tourism industry, where air conditioning (AC) equipment consumes a significant amount of electrical energy, typically accounting for around 60% of the electricity usage. The purpose of this research is to analyze the consumption of electrical energy related to the operational efficiency of a hotel building. Energy auditing is the technique used to calculate the energy consumption and determine methods to control it in order to achieve energy savings. The activity involves determining the “Energy Efficiency Ratio” based on standards applied in Indonesia. By implementing electrical energy conservation measures, there can be economic benefits as well. The more efficient the energy usage, the lower the costs incurred to meet electricity needs. Keywords : Conservation Energy, Cold Storage
Perbandingan Kinerja 4 Mesin ATF Charger untuk Proses Flashing pada Transmisi Toyota Yaris Matic Wanda Wanda; Koswara Koswara; A Djoko Wiyono
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 33 No 3 (2023): Sainstech: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v33i3.1662

Abstract

ABSTRACT This research is an experiment testing several Automatic Transmission Fluid (ATF) charger machines in the Flushing process during oil changes by comparing several ATF machines with the Toyota Yaris automatic transmission hydraulic pump. By knowing the performance of each of these tools, we can recommend a better and more efficient use for automatic car maintenance. The purpose of this study was to compare the ATF Charger Lounch Cat-501s, ATF Charger brand X1, ATF Charger brand X2 with a Toyota Yaris automatic transmission hydraulic pump. By knowing the performance of each of these tools, we can recommend a better and more efficient use for automatic car maintenance. besides that it also aims to find out the maintenance of the automatic transmission on the Toyota Yaris automatic transmission hydraulic pump. The method in this study uses experimental methods by conducting literature studies, sample preparation, group division, treatment implementation, measurement and observation and measurement of the speed of oil entering the transmission during flashing, data analysis, data interpretation, and report generation. The data collected includes efficiency, output power, generated pressure, costs incurred including maintenance costs. In addition, testing was also carried out to evaluate the performance of the Toyota Yaris automatic transmission hydraulic pump when using each type of ATF Charger machine during Flushing. The results showed that the ATF Brand X1 engine had the fastest performance in the process of changing the engine oil for the transmission of the Toyota Yaris automatic car, which was able to drain 1000 ml in 17.65 seconds, the speed was around 850 rpm (revolutions per minute), with an electric voltage of 12 Volts, as well as the cost of procuring the lowest equipment, which is IDR 1,807,530 Keywords: ATF Charger, Toyota Yaris, Matic
Analisis Optimalisasi Pemanfaatan Alumunium dari Sisa Proses Produksi Menjadi Bahan Baku Produksi Dengan Mempertimbangkan Aspek Kualitas, Biaya dan Mutual Benefit Dengan Pihak Ketiga Kristovel Sihaloho; Koswara Koswara
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 33 No 2 (2023): Sainstech: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v33i2.1716

Abstract

Abstract PT ABC is a company engaged in the two-wheeled automotive manufacturing industry that wants to optimize the use of aluminum scrap left over from machining production and processing it into raw materials is carried out by third parties or suppliers with quality standards set by PT ABC. However, processed raw materials are the cause of high product defects because the ferrous content is always high. The first stage in reducing the level of disability is to identify the influencing factors. The method used is a fishbone diagram, followed by the Taguchi method to find out the factors that most influence the cause of product defects. From the results of data processing with a fishbone diagram, there are three influential factors. Among these three factors, the factor with the greatest influence is sought which results in product quality deviating from quality standards. From the results obtained it was concluded that product defects were caused by the percentage of ferrous content of 1.15%, while the percentage of application results using the Taguchi method was 0.09%. Decreasing the percentage of ferrous content affects product quality improvement, lower production raw material purchase costs and mutual benefits with third parties.
Influence of the Oriented Configuration of the BarChip Fibre Polypropylene to the Ductility Factor of the Reinforced Concrete Beam Daniel RT Siregar; Koswara Koswara; Syahril Taufik
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 33 No 3 (2023): Sainstech: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v33i3.1867

Abstract

Abstract Bending and shear strength of fiber reinforced polimer concrete beams was studied in this research project. The reinforced concrete beam behaves in brittle structure in the certain reinforcement configuration. BarChip fibre polypropylene as the material for enhancement of the ductility factor is applied to the concrete beam. Three types of BarChip fibre configuration were examined: randomly spreading, placing at the mid-span area, and concentration on the tension zone. The experimental program included five beam specimens. Two of the beams were control specimens in which one was reinforced with no fibre, while the other one did not have any Barchips polypropylene. Each one of the other three specimens was reinforced with one of the above mentioned fibers by 0,4% volumetric ratio. Investigating the following issues for medium-high concrete strength was the goal of this study. In order to determine whether adding 0.4% volumetric ratio of polypropylenes as additional bar reinforcement in beams would provide adequate strength and stiffness properties comparable to reinforcing steel used as minimum bar reinforcement, it was necessary to first assess the effectiveness of each type of oriented fiber configuration on the bending strength, then to look into each beam's bending strength, shear strength, toughness, crack patterns, and near ultimate load crack width. The findings demonstrated that the bending capacity of the beam specimens was raised by all three types of polypropylene configuration more than by the beam reinforced with the fewest amount of bar reinforcement. Additionally, some of the employed fibers may cause failures other than pure shear. It is reccomended to spread the polypropylene within the tension zone of the reinforced concrete beam on the bottom mid span. Keywords: Fibrous Concrete, Polypropylene, Ductility, Reinforced, Beam
Co-Authors A Djoko Wiyono Daniel RT Siregar Gugum Gumilar Istadi Istadi Kristovel Sihaloho Muhammad Fitrullah Nofirman Nofirma Ricky Parmonangan Syahril Taufik Wanda Wanda Wishnuwardhana Jam Y. Bindar