Article Per Year (5 Year)
p-Index From 2021 - 2026
0
P-Index
This Author published in this journals
All Journal Simposium II UNIID 2017 JMES The International Journal of Mechanical Engineering and Sciences
Suwarno Suwarno
Institut Teknologi Sepuluh Nopember
Computer Science & IT Decision Sciences, Operations Research & Management Energy Materials Science & Nanotechnology Mechanical Engineering

Published : 5 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 5 Documents
Search

 1 
BAHAYA PEMOMPAAN AIR TANAH TERHADAP LAND SUBSIDENCE PADA LAPISAN TANAH LUNAK Suwarno Suwarno
Simposium II UNIID 2017 Vol 2 (2017)
Publisher : Simposium II UNIID 2017

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (514.936 KB)

Abstract

Pemakaian air tanah yang berlebihan akan mengakibatkan penurunan muka tanah yang sangat luas (land subsidence). Tidak sedikit kerugian yang diakibatkan oleh land subsidence, sebagai contoh diantaranya adalah turunnya konstruksi jetty di Terminal Peti Kemas dan daerah sekitar pelabuhan Tanjung Emas Semarang. Tujuan mencari penyebab land subsidence sangatlah penting untuk memperkecil dampak penurunan tanah yang akan terjadi di masa mendatang. Metodologi yang paling sederhana untuk mencatat penurunan tanah adalah dengan melakukan pemetaan topografi secara berkala. Namun hal yang sangat penting dipelajari adalah mencari penyebab utama peristiwa land subsidence. Adapun beberapa faktor penyebab penurunan permukaan tanah antara lain proses-proses geologi seperti aktifitas vulkanik dan tektonik, siklus geologi, adanya rongga di bawah permukaan tanah; pengambilan bahan cair dari dalam tanah seperti air tanah atau minyak bumi; adanya beban-beban berat diatasnya seperti struktur bangunan sehingga lapisan-lapisan tanah dibawahnya mengalami kompaksi atau konsolidasi. Hasil yang diperoleh dari analisa probablitas penyebab terjadinya land subsidence menjadi dasar penanganan pencegahan atau memperkecil kerusakan yang terjadi akibat land subsidence. Kesimpulan yang didapatkan sebagai penyebab land subsidence bukanlah pemompaan air tanah semata, melainkan banyak hal diantaranya pembebanan yang melebihi daya dukung tanah maupun penurunan muka tanah akibat pengambilan bahan padat dari tanah (aktifitas pengerukan).
Numerical Study of Characteristics Root Canal Irrigation using Open-Ended Needle Positive Pressure and Negative Pressure Method Fajar Dwi Yudanto; Wawan Aries Widodo; Suwarno Suwarno
JMES: The International Journal of Mechanical Engineering and Sciences Vol 4 No 1 (2020)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25807471.v4i1.7128

Abstract

This study aims to determine the characteristics of fluid flow through root canal irrigation using positive and negative pressure methods used CFD (Computational Fluid Dynamic) software by modeling root canals and needle insertion in the root canals. This modeling used a steady flow, an incompressible flow, and uniform flow at the inlet side, and the roughness of the root canal wall surface is neglected (smooth wall). The open-ended needle with different insertion lengths applied for each method with a flow rate of 0.2 mL/s or about 6.63 m/s and the Reynolds number is 1376 (Laminar). The fluid has 2.5% of NaOCl with the density of 1060 kg/m3 and 0.001 Pa.s of fluid viscosity. After considering factors such as velocity, dynamic pressure, and wall shear stress in both methods, a greater velocity value in the apical region is determined by using a positive pressure method. Meanwhile, the negative pressure method shows the ability to lift higher due to shear stress, which is more evenly distributed upwards. However, both methods are qualified for irrigation replacement in the apical region.
Study on The Effect of Cold-Rolling and Subsequence Welding on the Corrosion Rate of 304L Niko Arianto; Suwarno Suwarno
JMES: The International Journal of Mechanical Engineering and Sciences Vol 3 No 1 (2019)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25807471.v3i1.8967

Abstract

Corrosion is an event of material damage due to reacting chemically with the environment. Stainless steel is a widely used steel in the industrial world, for example, the austenitic stainless-steel type 304L. The problem that still arises with 304L stainless steel is corrosion at grain boundaries. The sensitization process occurs when the steel is heated at a temperature of 500 °C – 700 °C resulting in chromium carbide precipitation formation. Sensitization of austenitic stainless steel can occur during the welding process, which can cause damage to the heat-affected zone (HAZ). Cold working on metals is a deformation process that is carried out at temperatures below the recrystallization temperature. This research was conducted to determine the effect of variations in rolling and welding. Rolling was carried out using a cold working process with a variation of the workpiece reduction, namely 20%, 40%, and 60%. Welding was carried out with current variations of 50, 65, and 80 with a welding timeof 5 s and 10 s. The corrosion rate was tested using a potentiostat to obtain current density (Icorr) and potential (Ecorr) data. From the research, it was found the relation between rolling, welding parameters, and the corrosion rate. The corrosion rate is controlled by the carbide precipitation in the HAZ regime.
Analysis of Scale Deposit in the Geothermal Power Plant Afifah Harmayanti; Suwarno Suwarno
JMES: The International Journal of Mechanical Engineering and Sciences Vol 2 No 1 (2018)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25807471.v2i1.5168

Abstract

Gunung Salak is one of the potential geothermal area in Indonesia. The steam character is categorised as the water – dominated steam with low steam purity. During inspection, deposit was found in several equipment which are turbine, demister, scrubber and separator. Demister is an essential in the geothermal system as it keeps the steam quality above the saturated condition, by removing the water phase from the steam. The deposit was predicted to be form because of scaling problem due to the impurities of the steam. Oxygen is expected to be responsible of the scaling problem. This research is to analyze the effect of oxygen partial pressure to the formation of scaling through thermodynamic approach. The formation of iron oxide scaling is to be focused in this research as it is mostly found in the deposit alongside other compounds. Demister’s deposit was analyzed using ICP, AAS, XRD and SEM – EDX method. The actual composition found in the demister is then compared to the phase stability diagram results using a chemical reaction software. The deposit used is from the demister.
Failure Analysis of Bend Tube Preheater on Heat Recovery Steam Generator R. Sony Endardo Putro; Arif Hariyadi; Suwarno Suwarno
JMES: The International Journal of Mechanical Engineering and Sciences Vol 1 No 1 (2017)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25807471.v1i1.2222

Abstract

The combined cycle power plant (PLTGU) is the second largest percentage of electrical production method which is 26% of all electrical production technology in Indonesia. One of the components in combined cycle power plant is the heat-recovery steam generator (HRSG), which serves as heat-exchanger between hot gasses from gas turbine cycle and water from steam turbine cycle. There are four stages on HRSG, preheater, economizer, evaporator, and superheater. In the present work, there is a case of thinning on a bend tube preheater which exceeds the tolerance limits, therefore the purposes of this research determine the cause of failure and determine the failure mechanism on bend tube preheater. Thinning of bend tube preheater occurred due to corrosion from both the inside surface and outside surface. Corrosion that occurred on the inside surface of bend tube preheater caused by a reaction between water and metal surface of the tube. Corrosion on the outside surface could be happen caused by a reaction between the hot gas and metal surface of the tube. Largest thinning rate occurred on bend area of bend tube preheater caused by deformation itself, it induces local reduction of breakdown potential.
Co-Authors Afifah Harmayanti Arif Hariyadi Fajar Dwi Yudanto Niko Arianto R. Sony Endardo Putro Wawan Aries Widodo