Sigit Tri Wicaksono | Institut Teknologi Sepuluh Nopember (original) (raw)

Papers by Sigit Tri Wicaksono

Research paper thumbnail of Molecular structure effects on CO2 absorption in Room Temperature Ionic Liquids

Research paper thumbnail of Effect of Zn and NH4HCO3 on degradation rate and mechanical properties of porous Mg-Zn alloys for degradable biomaterials

Nucleation and Atmospheric Aerosols, 2018

Influence of composition grafit oxide, irradiation-time variation analyzes on reduced graphene ox... more Influence of composition grafit oxide, irradiation-time variation analyzes on reduced graphene oxide-copper oxide (rGO/CuO) composite toward photocatalytic conversion of CO 2 to methanol

Research paper thumbnail of Effect of thermoset plastics addition on physical and mechanical properties of plastics waste composite for construction materials application

Nucleation and Atmospheric Aerosols, 2018

Stress analysis on tensile loaded honeycomb sandwich structured material of poly lactic acid fila... more Stress analysis on tensile loaded honeycomb sandwich structured material of poly lactic acid filament

Research paper thumbnail of Oxidation Behavior and Micro Structure Analysis of Nuclear Graphite IG-110 at 520℃ Under Air Environment

Materials Research Communications, Nov 30, 2021

Graphite IG-110 is a nuclear graphite structural and moderator material that has been used for hi... more Graphite IG-110 is a nuclear graphite structural and moderator material that has been used for high temperature gas cooled reactors (HTGR). Under normal operating conditions or accidental entry of air or water (air ingress or water ingress), a nuclear graphite. Therefore, the aim of this study is to investigate the oxidation resistant and microstructure change behavior of graphite IG-110 at high temperature under air environment. The sample of IG-110 was tested using Magnetic Suspension Balance (MSB) to analyze the weight change by in-situ for 420 minutes at a temperature of 520 o C. Morphological and microstructure analysis was carried out by optical microscope, SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Sprectroscope) and XRD (X-Ray Diffractometer). The results showed that Graphite IG-110 has a change in surface structure caused by the reaction of the material with oxygen in air at high temperatures. Furthermore, the crystal size of the material structure was slightly change. However, in general, the corrosion rate of graphite IG-110 at a temperature of 520℃ under the air environment is relatively low. So that if graphite IG-110 is exposed to air at a temperature of 520℃ for several hundred minutes in a nuclear reactor estimated does not suffer serious damage.

Research paper thumbnail of Scratch Area Effect in Coating to Protection Current Needing in ICCP System for AISI 1045 Steel in Sea Water Environment

IPTEK Journal of Proceedings Series, Jul 3, 2015

Every metal always going back to its oxide form. Steel which are oxidized having lower quality t... more Every metal always going back to its oxide form. Steel which are oxidized having lower quality than steel which are not. Oxidizing steel will going faster if it is placed in corrosive environment. Sea water is one of the environment that support the oxidizing process. Coats are using to protect the steel in sea water. But sometimes there is some failure in coating process so the coat will have scratch damage area. The objective of this experiment is to know how much current needed to protect AISI 1045 steel which have been coated with polyethylene and given scratch area with shape variations, in sea water environment. This experiments is the continuation from the past experiences which is using sacrifice anode, on the other hand, this experiences using Impressed Current Cathodic Protection. Data which are taken from this experiment is the differentiation of potential that measured with electrode reference Cu/CuSO4, and the current measured by avometer. With ICCP system, we know that the corrosion rate in rectangular-shape scratch is faster than circle-shape scratch, and the larger the area of scratch, the larger current needed to protect the coated steel.

Research paper thumbnail of Studi Pengaruh Penambahan PVA dan Bentonit Terhadap Morfologi dan Sifat Fisik Komposit Berbasis Hidrogel Alginat Sebagai Kandidat Material Perancah Untuk Regenarasi Tulang Rawan

Jurnal Teknik ITS, Apr 22, 2019

Pemanfaatan rumput laut cokelat khususnya didaerah Madura dimana lokasinya yang dekat dengan Sura... more Pemanfaatan rumput laut cokelat khususnya didaerah Madura dimana lokasinya yang dekat dengan Surabaya, hanya sebatas untuk makanan warga sekitar. Hal ini menjadi acuan untuk mengembangkan dan meningkatkan potensi rumput laut cokelat dengan mengekstrak salah satu kandungannya yaitu alginat untuk dikembangkan ke arah biomedis khususnya material perancah (scaffold). Dikarenakan keterbatasan sifat fisik dan mekaniknya, maka mulai dikembangkan hidrogel alginat dengan penambahan beberapa material untuk meningkatkan sifat tersebut. Dalam penelitian ini akan dianalisa pengaruh penambahan PVA dan bentonit terhadap morfologi dan sifat fisik komposit berbasis hidrogel alginat serta menganilisis fisibilitas alginat hasil ekstraksi. Sintesis komposit hidrogel alginat/PVA/bentonit dimulai dengan pengekstrasian sodium alginat dari Sargassum sp. asal Sumenep, Madura melalui jalur CaCl2 kemudian dilanjutkan dengan pembuatan hidrogel alginat. Pembuatan komposit hidrogel alginat/PVA/bentonit ini dengan tambahan PVA dan bentonit sebanyak 5%, 10%, 15%, 20%, 25%, dan 30% wt dari masing-masing bahan ke hidrogel alginat dengan pelarut aquades. Sampel kemudian diuji menggunakan XRF, FTIR, XRD, SEM, viscosity bath, dan hydrolitic degradation. Dari pengujian diatas didapatkan komposisi optimum untuk komposit adalah 70A/15B/15P dan sodium alginat ekstraksi memiliki fisibilitas yang baik untuk dijadikan alternatif pengganti sodium alginat komersil sebagai material perancah. Modifikasi alginat ini diharapkan dapat menjadi kandidat material perancah (scaffold) tulang rawan yang mempunyai sifat biokompatibilitas dan biodegradibilitas yang baik. Selain itu, penelitian ini juga menjadi dasar untuk pemanfaatan hasil ekstraksi bahan alam yang kedepannya dapat dimanfaatkan sebagai bioink pada proses manufaktur 3D printed.

Research paper thumbnail of Internal geometry effect of structured PLA materials manufactured by dropplet-based 3D printer on its mechanical properties

Nucleation and Atmospheric Aerosols, 2018

Rapid Prototyping (RP) technologies, the manufacturing technology with less time consuming includ... more Rapid Prototyping (RP) technologies, the manufacturing technology with less time consuming including high precission and complicated structure of products, are now become high demanding technologies. Those technologies can be base on top-down or bottom-up approaches. One of the bottom-up approach of RP technology is 3D printing machine. In this research, we have succeed to apply the droplet-based 3D printer to make the structured PLA (Polylactic Acid) materials with different internal geometry structures. The internal geometry used are triangle and honeycomb structure with different size of each symmetry axis of 4.5 mm and 9 mm and the thickness varied of 1 mm and 2 mm as well. The mechanical properties of those structures including tensile and bending stregth are evaluated by using tensile and flexural test respectively. Test results show that the best performance obtained by measuring its tensile and flexural strength is the sampel with triangle geometry of 9 mm geometrical size and 2 mm of thickness. T...

Research paper thumbnail of Synthesis and Characterization of Acrylic-Based Photopolymer as a Candidate for Denture Base Material

IOP conference series, May 1, 2017

Denture base is a denture part that rests on the soft tissue covering the jawbone and becomes an ... more Denture base is a denture part that rests on the soft tissue covering the jawbone and becomes an anchor of a denture. The material that commonly used for this purpose is poly (methyl methacrylate). However, it lacks in mechanical properties due to high water absorption. The aim of this research was to improve the physical and mechanical properties of poly (methyl methacrylate) by making a copolymer with styrene via photopolymerization process. In this method was used the addition of styrene monomer at 10, 20, 30, 40, and 50 wt% into the acrylic resin to form copolymer materials via photopolymerization process. The amount of 1.5 wt% Irgacure 784's photoinitiator was added as a photoinitiator. The results showed that the addition of 40% by weight of styrene copolymer is the best performance compare to the addition styrene of 10, 20, 30, and 50%. The samples with an addition styrene of 40 wt% showed excellent properties such as high water absorption value of 2.405 μg/mm 3 , the solubility of 0.434 μg/mm 3 , the flexural strength of 69.336 MPa, a flexural modulus of 1.236 GPa, and a hardness value of 82.583 HD. Poly (methyl methacrylate-co-styrene) copolymer with the addition of styrene 40 wt% has the closest value to the requirements for a denture base material.

Research paper thumbnail of Study on mechanical and physical properties of composite materials with recycled PET as fillers for paving block application

Nucleation and Atmospheric Aerosols, 2018

Base on Sidoarjo’s goverment data, there was more than 4000 metric ton perday of waste that has b... more Base on Sidoarjo’s goverment data, there was more than 4000 metric ton perday of waste that has been accumulated during 2016. More than 10 percent from overall waste is plastics. In accordance with the Indonesia government regulation, “Indonesia clean from waste” by 2020 through 3R (Reduce, Reuse and Recycle) program, we have been focusing research on how to reduce the accumulation of the plastics waste in Sidoarjo by processing it become a new product. In this research, we have made the plastic waste of PET bottle as additional fillers or agregates of composite material for construction application as a paving block. The composition of PET plastic used as fillers is vary from 0, 10, 20, 30, 40 and 50% from total volume of agregates. The ratio of cement binder to sands agregate is 1:3. The specimens were characterized its mechanical and physical properties by using flexural testing, compressive testing, density and water absorbance measurement. The results show that the mechanical (flexural and compressive) properties of composite materials is increased significantly by increasing PET fillers up to 20%, however it was decreased when PET content more than 20%. But, both the density and water absobance of specimens are decreased by increasing of PET fillers.Base on Sidoarjo’s goverment data, there was more than 4000 metric ton perday of waste that has been accumulated during 2016. More than 10 percent from overall waste is plastics. In accordance with the Indonesia government regulation, “Indonesia clean from waste” by 2020 through 3R (Reduce, Reuse and Recycle) program, we have been focusing research on how to reduce the accumulation of the plastics waste in Sidoarjo by processing it become a new product. In this research, we have made the plastic waste of PET bottle as additional fillers or agregates of composite material for construction application as a paving block. The composition of PET plastic used as fillers is vary from 0, 10, 20, 30, 40 and 50% from total volume of agregates. The ratio of cement binder to sands agregate is 1:3. The specimens were characterized its mechanical and physical properties by using flexural testing, compressive testing, density and water absorbance measurement. The results show that the mechanical (flexural and compressiv...

Research paper thumbnail of Iron (Ii, Iii) Oxide–Graphene/Polyethylene Glycol–Silicon Dioxide as a Phase Change Material for Thermal Energy Storage

Research paper thumbnail of Pengaruh Komposisi Filler Limbah Polypropylene dan Sekam Padi terhadap Sifat Fisis dan Mekanik Komposit untuk Aplikasi Papan Semen Partikel

Jurnal Teknik ITS, Dec 18, 2019

Papan partikel semen komposit memiliki potensial dalam memproduksi aplikasi pembangunan. Aplikasi... more Papan partikel semen komposit memiliki potensial dalam memproduksi aplikasi pembangunan. Aplikasi yang diproduksi dari papan partikel semen memiliki kekuatan dan ketangguhan lebih dari papan partikel kayu. Selain itu, papan partikel semen juga lebih tahan akan api atau panas dan kedap akan suara. Papan partikel semen biasanya digunakan dalam pembangunan fisik di sektor konstruksi seperti penggunaan pada dinding panel sebagai aplikasi tahan api dan kedap suara. Karena proses pembuatan semen berperan sebagai penyumbang gas karbon dioksida dalam proses produksinya dan salah satu jenis semen adalah semen pre-mix mortar. Salah satu upaya untuk mengurangi dampak negatif terhadap lingkungan dari produksi semen adalah menggunakan material limbah sebagai filler komposit untuk mengurangi penggunaan semen. Material limbah berupa serat alam yang dapat digunakan sebagai penguat pada komposit adalah serat sekam padi. Bahan limbah lain yang bisa digunakan sebagai pengisi adalah polypropylene dan bata ringan. Bata ringan merupakan salah satu bahan utama untuk konstruksi dinding. Penelitian ini dilakukan dengan berbagai variasi komposisi sekam padi dan polypropylene pada komposit sekam padi/ polypropylene/ bata ringan/ semen untuk aplikasi papan partikel. Pengujian yang dilakukan berupa pengujian fisis (absorbsi air dan densitas), pengujian mekanik (beban lentur dan kuat tekan) serta pengujian mikroskop optik. Hasil penelitian menunjukkan bahwa penambahan sekam padi dan polypropylene dapat memberikan sifat fisis dan mekanis yang lebih baik pada komposisi tertentu. Nilai pengujian sifat fisis dan mekanis papan semen partikel tidak seluruhnya memenuhi standar SNI 03-2105-2006, namun seluruhnya telah memenuhi standar ISO 8335. Nilai kuat lentur dan kuat tekan tertinggi dimiliki oleh komposit dengan variasi komposisi 0,5 phr sekam padi dan 0.5 phr polypropylene dengan nilai masing-masing sebesar 149,29 dan 523 kgf/cm 2 .

Research paper thumbnail of A Composite of Hydrogel Alginate/PVA/r-GO for Scaffold Applications with Enhanced Degradation and Biocompatibility Properties

Polymers, Jan 19, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Pengaruh Komposisi Filler Limbah Cangkang Kerang dan Fiberglass terhadap Sifat Fisis dan Mekanik Komposit untuk Aplikasi Papan Partikel Semen

Jurnal Teknik ITS, Dec 31, 2019

Papan partikel yang saat ini populer dikembangkan adalah papan partikel semen. Namun semen memili... more Papan partikel yang saat ini populer dikembangkan adalah papan partikel semen. Namun semen memiliki dampak buruk untuk lingkungan, maka penggunaan limbah sebagai campuran matriks dan filler akan mengurangi penggunaan semen. Material limbah tersebut adalah bata ringan dan cangkang kerang. Selain cangkang kerang, digunakan juga penguat berupa serat gelas yang memiliki sifat fisis dan mekanis yang baik.. Penelitian ini dilakukan dengan berbagai variasi komposisi cangkang kerang, dan serat gelas pada komposit untuk aplikasi papan partikel semen. Pengujian yang dilakukan berupa pengujian fisis (absorpsi air dan densitas) dan pengujian mekanik (beban lentur dan kuat tekan). Dari hasil penelitian diketahui bahwa penambahan cangkang kerang dan serat gelas mampu membuat sifat fisis dan mekanik papan partikel lebih baik jika dibandingkan tanpa filler. Hasil dari pengujian sudah memenuhi semua standard ISO 8335, dengan nilai kuat lentur dan kompresi tertingginya masing-masing adalah 118,26 kgf/cm 2 dan 547 kgf/cm 2. Kata kunci-serat gelas, limbah bata ringan, limbah cangkang kerang, papan partikel

Research paper thumbnail of Degradation rate improvement of magnesium alloy AZ31 using plasma electrolytic oxidation as biodegradable implant

Nucleation and Atmospheric Aerosols, 2021

The aim of this research is to improve degradation rates of magnesium alloys AZ31 as biodegradabl... more The aim of this research is to improve degradation rates of magnesium alloys AZ31 as biodegradable implant using Plasma Electrolytic Oxidation (PEO) method. Magnesium alloys AZ31 is used as temporary biomaterials due to good mechanical and biocompatibility, however the degradation rate is weekness of the material. In this study, Plasma Electrolytic Oxidation was employed to grow oxide on surface by creating plasma using high voltage electrical source. This study to analyze the influence of sodium silicate concentration and oxidation time on morphology, mechanical property, and degradation rates on magnesium AZ31 alloys during PEO. The variations of sodium silicate concentration are 0.025, 0.035 and 0.045M with oxidation times of 5 to 15 minutes. Based characterisaion using XRD was found that there were two new compounds exist of the surface such as MgO and Mg 2SiO4. The results of SEM / EDX on the surface showed that the higher the concentration of sodium silicate and the oxidation time influence the pore diameter size become bigger and increase the thickness. In addition, based on AFM investigation, the surface roughness that was measured by micro vicker method has three times that was compared to untreated sample till peak condition while the concentration up to 0.045M and an increase in oxidation time of up to 15 minutes and then the hardness was decreased. In the rate of degradation evaluation using the weight loss method that the lowest degradation rate is during deposition using 0.025M sodium silicate concentration and 10 minutes oxidation time with a degradation rate of 2,89 mm / year.

Research paper thumbnail of Mechanical and Thermal Properties of Unsaturated Polyester/Vinyl Ester Blends Cured at Room Temperature

IOP conference series, May 1, 2017

Unsaturated polyester (UP) resin containing aromatic ring was blended with vinyl ester (VE) at wi... more Unsaturated polyester (UP) resin containing aromatic ring was blended with vinyl ester (VE) at wide range composition (10, 20, 30, 40,and 80 wt.%) using mechanical blending method. The blends were cured at room temperature using methyl ethyl ketone peroxide (MEKP) (4 wt.%) as catalyst initiator without the presence of catalystaccelerator. The effect of vinyl ester composition on theenhancement of mechanical and thermal properties of unsaturated polyester/vinyl ester blends was investigated.The polymer blends were characterized by Fourier Transform Infra Red (FTIR)spectroscopy, tensile testing, hardness testing, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). IR spectra showed UP and VE peaks. The curing copolymerization reactionoccurred at vinyl (C=C) bonds. The addition of vinyl esters enhanced mechanical and thermal properties. The UP/VE blends showed homogeneous morphology, transparent and copolymer thermoset blend.

Research paper thumbnail of Pengaruh Holding Time Pada Proses Post Heat, Laju Pendinginan Dan Waktu Perendaman Dalam Air Hujan Terhadap Kekerasan Dan Struktur Mikro Pada Pengelasan Gtaw Baja T91

Boiler merupakan suatu ketel uap yang menghasilkan energi uap panas. Salah satu bagian boiler ter... more Boiler merupakan suatu ketel uap yang menghasilkan energi uap panas. Salah satu bagian boiler tersusum atas pipapipa ataupun sambungan-sambungan lasan, pada pipa boiler terdapat material T91 yang masih asing digunakan dalam industri. Sehingga perlu di adakan penelitian lebih lanjut untuk memperoleh hasil yang maksimal dari pengelasan gas tungsten arc welding (GTAW) material T91. Penelitian ini bertujuan untuk meneliti pengaruh holding time pada proses post heat, laju pendinginan dan waktu perendaman dalam air hujan terhadap kekerasan dan struktur mikro. Dalam penelitian ini variasi post heat holding time 30, dan 60 menit serta laju pendinginan lambat dan udara, serta tanpa perendaman dan perendaman dalam air hujan kota Surabaya selama 7 hari. Hasil penelitian menunjukkan bahwa semakin lama waktu holding time dan semakin cepat laju pendinginan maka nilai kekerasannya akan semakin naik yaitu nilai kekerasan 230 HV pada weld metal. Perubahan nilai kekerasan setelah direndam dalam air hujan mengelami penurunan sekitar 5 HV.

Research paper thumbnail of Experimental Analysis on The Tensile Strength of Polyester Resin based Calcium Carbonate Powder and E-Glass Fibre Reinforced Composite

IOP conference series, Jun 26, 2019

Calcium carbonate powder is contained in the waste produced from processing limestone. Limestone ... more Calcium carbonate powder is contained in the waste produced from processing limestone. Limestone is used as an alternative substitute for organic fillers in polymer composites. The use of this waste can be a valuable resource as a replacement filler in polymer composites. The main purpose of this study is to reuse the waste materials calcium carbonate for composite materials. E-glass type woven roving is used as reinforcement and polyester resin was is as a matrix. In the present research, the addition of calcium carbonate waste powder in composites E-glass/polyester was investigated for tensile strength and density. In the hybrid, composite specimen of this study was prepared using hand lay-up technique. Tensile testing was carried out according to ASTM D368 standard. At first, calcium carbonate powder, glass fibre, and polyester were prepared in a specific volume and the specimens were prepared. Comparison filler plays an important role in producing the tensile strength of the composite. Thus, the fill ratio was considered as an experimental variable and were varied (2.5, 5.0, 7.5, and 10% by weight for calcium carbonate; 10, 12.5, 15, and 17.5% by weight for E-Glass. After testing was carried out, it is found that the strength of the material was increased as the volume of E-glass fibre increased.

Research paper thumbnail of Physical and mechanical properties of solid waste based LPDE/multi fillers composite

ADVANCES IN FRACTURE AND DAMAGE MECHANICS XX

Research paper thumbnail of Fabrication of high aspect-ratio metallic nanotube array with highly-ordered periodicity using HiPIMS

Journal of Alloys and Compounds

Research paper thumbnail of Design Analysis of External Airbag System at The Toyota Venza Vehicle

2020 6th International Conference on Computing Engineering and Design (ICCED), 2020

Airbag is technology in the automotive sector which was created to save the passenger from fatal ... more Airbag is technology in the automotive sector which was created to save the passenger from fatal risks in vehicle accident. Airbag are placed at the point of risk of passenger collision so that the impact load generated from this impact will be muted by airbags of the passenger. This research is designed to be able to perform rescue function not only for passenger, but also for vehicle itself. Because the placement of the airbags was placed on the bumper of vehicle, this part is installed with a high sensitivity sensor to be able to provide information to the system. So the airbags can expand before a impact occurs and the vehicle and its contents will be protected. ECU will send a signal to the squib inflator or also known as an igniter which is an electrical device in the form of a thin bridge cable, igniter will generate heat to burn propylene airbags which will produce nitrogen gas.

Research paper thumbnail of Molecular structure effects on CO2 absorption in Room Temperature Ionic Liquids

Research paper thumbnail of Effect of Zn and NH4HCO3 on degradation rate and mechanical properties of porous Mg-Zn alloys for degradable biomaterials

Nucleation and Atmospheric Aerosols, 2018

Influence of composition grafit oxide, irradiation-time variation analyzes on reduced graphene ox... more Influence of composition grafit oxide, irradiation-time variation analyzes on reduced graphene oxide-copper oxide (rGO/CuO) composite toward photocatalytic conversion of CO 2 to methanol

Research paper thumbnail of Effect of thermoset plastics addition on physical and mechanical properties of plastics waste composite for construction materials application

Nucleation and Atmospheric Aerosols, 2018

Stress analysis on tensile loaded honeycomb sandwich structured material of poly lactic acid fila... more Stress analysis on tensile loaded honeycomb sandwich structured material of poly lactic acid filament

Research paper thumbnail of Oxidation Behavior and Micro Structure Analysis of Nuclear Graphite IG-110 at 520℃ Under Air Environment

Materials Research Communications, Nov 30, 2021

Graphite IG-110 is a nuclear graphite structural and moderator material that has been used for hi... more Graphite IG-110 is a nuclear graphite structural and moderator material that has been used for high temperature gas cooled reactors (HTGR). Under normal operating conditions or accidental entry of air or water (air ingress or water ingress), a nuclear graphite. Therefore, the aim of this study is to investigate the oxidation resistant and microstructure change behavior of graphite IG-110 at high temperature under air environment. The sample of IG-110 was tested using Magnetic Suspension Balance (MSB) to analyze the weight change by in-situ for 420 minutes at a temperature of 520 o C. Morphological and microstructure analysis was carried out by optical microscope, SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Sprectroscope) and XRD (X-Ray Diffractometer). The results showed that Graphite IG-110 has a change in surface structure caused by the reaction of the material with oxygen in air at high temperatures. Furthermore, the crystal size of the material structure was slightly change. However, in general, the corrosion rate of graphite IG-110 at a temperature of 520℃ under the air environment is relatively low. So that if graphite IG-110 is exposed to air at a temperature of 520℃ for several hundred minutes in a nuclear reactor estimated does not suffer serious damage.

Research paper thumbnail of Scratch Area Effect in Coating to Protection Current Needing in ICCP System for AISI 1045 Steel in Sea Water Environment

IPTEK Journal of Proceedings Series, Jul 3, 2015

Every metal always going back to its oxide form. Steel which are oxidized having lower quality t... more Every metal always going back to its oxide form. Steel which are oxidized having lower quality than steel which are not. Oxidizing steel will going faster if it is placed in corrosive environment. Sea water is one of the environment that support the oxidizing process. Coats are using to protect the steel in sea water. But sometimes there is some failure in coating process so the coat will have scratch damage area. The objective of this experiment is to know how much current needed to protect AISI 1045 steel which have been coated with polyethylene and given scratch area with shape variations, in sea water environment. This experiments is the continuation from the past experiences which is using sacrifice anode, on the other hand, this experiences using Impressed Current Cathodic Protection. Data which are taken from this experiment is the differentiation of potential that measured with electrode reference Cu/CuSO4, and the current measured by avometer. With ICCP system, we know that the corrosion rate in rectangular-shape scratch is faster than circle-shape scratch, and the larger the area of scratch, the larger current needed to protect the coated steel.

Research paper thumbnail of Studi Pengaruh Penambahan PVA dan Bentonit Terhadap Morfologi dan Sifat Fisik Komposit Berbasis Hidrogel Alginat Sebagai Kandidat Material Perancah Untuk Regenarasi Tulang Rawan

Jurnal Teknik ITS, Apr 22, 2019

Pemanfaatan rumput laut cokelat khususnya didaerah Madura dimana lokasinya yang dekat dengan Sura... more Pemanfaatan rumput laut cokelat khususnya didaerah Madura dimana lokasinya yang dekat dengan Surabaya, hanya sebatas untuk makanan warga sekitar. Hal ini menjadi acuan untuk mengembangkan dan meningkatkan potensi rumput laut cokelat dengan mengekstrak salah satu kandungannya yaitu alginat untuk dikembangkan ke arah biomedis khususnya material perancah (scaffold). Dikarenakan keterbatasan sifat fisik dan mekaniknya, maka mulai dikembangkan hidrogel alginat dengan penambahan beberapa material untuk meningkatkan sifat tersebut. Dalam penelitian ini akan dianalisa pengaruh penambahan PVA dan bentonit terhadap morfologi dan sifat fisik komposit berbasis hidrogel alginat serta menganilisis fisibilitas alginat hasil ekstraksi. Sintesis komposit hidrogel alginat/PVA/bentonit dimulai dengan pengekstrasian sodium alginat dari Sargassum sp. asal Sumenep, Madura melalui jalur CaCl2 kemudian dilanjutkan dengan pembuatan hidrogel alginat. Pembuatan komposit hidrogel alginat/PVA/bentonit ini dengan tambahan PVA dan bentonit sebanyak 5%, 10%, 15%, 20%, 25%, dan 30% wt dari masing-masing bahan ke hidrogel alginat dengan pelarut aquades. Sampel kemudian diuji menggunakan XRF, FTIR, XRD, SEM, viscosity bath, dan hydrolitic degradation. Dari pengujian diatas didapatkan komposisi optimum untuk komposit adalah 70A/15B/15P dan sodium alginat ekstraksi memiliki fisibilitas yang baik untuk dijadikan alternatif pengganti sodium alginat komersil sebagai material perancah. Modifikasi alginat ini diharapkan dapat menjadi kandidat material perancah (scaffold) tulang rawan yang mempunyai sifat biokompatibilitas dan biodegradibilitas yang baik. Selain itu, penelitian ini juga menjadi dasar untuk pemanfaatan hasil ekstraksi bahan alam yang kedepannya dapat dimanfaatkan sebagai bioink pada proses manufaktur 3D printed.

Research paper thumbnail of Internal geometry effect of structured PLA materials manufactured by dropplet-based 3D printer on its mechanical properties

Nucleation and Atmospheric Aerosols, 2018

Rapid Prototyping (RP) technologies, the manufacturing technology with less time consuming includ... more Rapid Prototyping (RP) technologies, the manufacturing technology with less time consuming including high precission and complicated structure of products, are now become high demanding technologies. Those technologies can be base on top-down or bottom-up approaches. One of the bottom-up approach of RP technology is 3D printing machine. In this research, we have succeed to apply the droplet-based 3D printer to make the structured PLA (Polylactic Acid) materials with different internal geometry structures. The internal geometry used are triangle and honeycomb structure with different size of each symmetry axis of 4.5 mm and 9 mm and the thickness varied of 1 mm and 2 mm as well. The mechanical properties of those structures including tensile and bending stregth are evaluated by using tensile and flexural test respectively. Test results show that the best performance obtained by measuring its tensile and flexural strength is the sampel with triangle geometry of 9 mm geometrical size and 2 mm of thickness. T...

Research paper thumbnail of Synthesis and Characterization of Acrylic-Based Photopolymer as a Candidate for Denture Base Material

IOP conference series, May 1, 2017

Denture base is a denture part that rests on the soft tissue covering the jawbone and becomes an ... more Denture base is a denture part that rests on the soft tissue covering the jawbone and becomes an anchor of a denture. The material that commonly used for this purpose is poly (methyl methacrylate). However, it lacks in mechanical properties due to high water absorption. The aim of this research was to improve the physical and mechanical properties of poly (methyl methacrylate) by making a copolymer with styrene via photopolymerization process. In this method was used the addition of styrene monomer at 10, 20, 30, 40, and 50 wt% into the acrylic resin to form copolymer materials via photopolymerization process. The amount of 1.5 wt% Irgacure 784's photoinitiator was added as a photoinitiator. The results showed that the addition of 40% by weight of styrene copolymer is the best performance compare to the addition styrene of 10, 20, 30, and 50%. The samples with an addition styrene of 40 wt% showed excellent properties such as high water absorption value of 2.405 μg/mm 3 , the solubility of 0.434 μg/mm 3 , the flexural strength of 69.336 MPa, a flexural modulus of 1.236 GPa, and a hardness value of 82.583 HD. Poly (methyl methacrylate-co-styrene) copolymer with the addition of styrene 40 wt% has the closest value to the requirements for a denture base material.

Research paper thumbnail of Study on mechanical and physical properties of composite materials with recycled PET as fillers for paving block application

Nucleation and Atmospheric Aerosols, 2018

Base on Sidoarjo’s goverment data, there was more than 4000 metric ton perday of waste that has b... more Base on Sidoarjo’s goverment data, there was more than 4000 metric ton perday of waste that has been accumulated during 2016. More than 10 percent from overall waste is plastics. In accordance with the Indonesia government regulation, “Indonesia clean from waste” by 2020 through 3R (Reduce, Reuse and Recycle) program, we have been focusing research on how to reduce the accumulation of the plastics waste in Sidoarjo by processing it become a new product. In this research, we have made the plastic waste of PET bottle as additional fillers or agregates of composite material for construction application as a paving block. The composition of PET plastic used as fillers is vary from 0, 10, 20, 30, 40 and 50% from total volume of agregates. The ratio of cement binder to sands agregate is 1:3. The specimens were characterized its mechanical and physical properties by using flexural testing, compressive testing, density and water absorbance measurement. The results show that the mechanical (flexural and compressive) properties of composite materials is increased significantly by increasing PET fillers up to 20%, however it was decreased when PET content more than 20%. But, both the density and water absobance of specimens are decreased by increasing of PET fillers.Base on Sidoarjo’s goverment data, there was more than 4000 metric ton perday of waste that has been accumulated during 2016. More than 10 percent from overall waste is plastics. In accordance with the Indonesia government regulation, “Indonesia clean from waste” by 2020 through 3R (Reduce, Reuse and Recycle) program, we have been focusing research on how to reduce the accumulation of the plastics waste in Sidoarjo by processing it become a new product. In this research, we have made the plastic waste of PET bottle as additional fillers or agregates of composite material for construction application as a paving block. The composition of PET plastic used as fillers is vary from 0, 10, 20, 30, 40 and 50% from total volume of agregates. The ratio of cement binder to sands agregate is 1:3. The specimens were characterized its mechanical and physical properties by using flexural testing, compressive testing, density and water absorbance measurement. The results show that the mechanical (flexural and compressiv...

Research paper thumbnail of Iron (Ii, Iii) Oxide–Graphene/Polyethylene Glycol–Silicon Dioxide as a Phase Change Material for Thermal Energy Storage

Research paper thumbnail of Pengaruh Komposisi Filler Limbah Polypropylene dan Sekam Padi terhadap Sifat Fisis dan Mekanik Komposit untuk Aplikasi Papan Semen Partikel

Jurnal Teknik ITS, Dec 18, 2019

Papan partikel semen komposit memiliki potensial dalam memproduksi aplikasi pembangunan. Aplikasi... more Papan partikel semen komposit memiliki potensial dalam memproduksi aplikasi pembangunan. Aplikasi yang diproduksi dari papan partikel semen memiliki kekuatan dan ketangguhan lebih dari papan partikel kayu. Selain itu, papan partikel semen juga lebih tahan akan api atau panas dan kedap akan suara. Papan partikel semen biasanya digunakan dalam pembangunan fisik di sektor konstruksi seperti penggunaan pada dinding panel sebagai aplikasi tahan api dan kedap suara. Karena proses pembuatan semen berperan sebagai penyumbang gas karbon dioksida dalam proses produksinya dan salah satu jenis semen adalah semen pre-mix mortar. Salah satu upaya untuk mengurangi dampak negatif terhadap lingkungan dari produksi semen adalah menggunakan material limbah sebagai filler komposit untuk mengurangi penggunaan semen. Material limbah berupa serat alam yang dapat digunakan sebagai penguat pada komposit adalah serat sekam padi. Bahan limbah lain yang bisa digunakan sebagai pengisi adalah polypropylene dan bata ringan. Bata ringan merupakan salah satu bahan utama untuk konstruksi dinding. Penelitian ini dilakukan dengan berbagai variasi komposisi sekam padi dan polypropylene pada komposit sekam padi/ polypropylene/ bata ringan/ semen untuk aplikasi papan partikel. Pengujian yang dilakukan berupa pengujian fisis (absorbsi air dan densitas), pengujian mekanik (beban lentur dan kuat tekan) serta pengujian mikroskop optik. Hasil penelitian menunjukkan bahwa penambahan sekam padi dan polypropylene dapat memberikan sifat fisis dan mekanis yang lebih baik pada komposisi tertentu. Nilai pengujian sifat fisis dan mekanis papan semen partikel tidak seluruhnya memenuhi standar SNI 03-2105-2006, namun seluruhnya telah memenuhi standar ISO 8335. Nilai kuat lentur dan kuat tekan tertinggi dimiliki oleh komposit dengan variasi komposisi 0,5 phr sekam padi dan 0.5 phr polypropylene dengan nilai masing-masing sebesar 149,29 dan 523 kgf/cm 2 .

Research paper thumbnail of A Composite of Hydrogel Alginate/PVA/r-GO for Scaffold Applications with Enhanced Degradation and Biocompatibility Properties

Polymers, Jan 19, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Pengaruh Komposisi Filler Limbah Cangkang Kerang dan Fiberglass terhadap Sifat Fisis dan Mekanik Komposit untuk Aplikasi Papan Partikel Semen

Jurnal Teknik ITS, Dec 31, 2019

Papan partikel yang saat ini populer dikembangkan adalah papan partikel semen. Namun semen memili... more Papan partikel yang saat ini populer dikembangkan adalah papan partikel semen. Namun semen memiliki dampak buruk untuk lingkungan, maka penggunaan limbah sebagai campuran matriks dan filler akan mengurangi penggunaan semen. Material limbah tersebut adalah bata ringan dan cangkang kerang. Selain cangkang kerang, digunakan juga penguat berupa serat gelas yang memiliki sifat fisis dan mekanis yang baik.. Penelitian ini dilakukan dengan berbagai variasi komposisi cangkang kerang, dan serat gelas pada komposit untuk aplikasi papan partikel semen. Pengujian yang dilakukan berupa pengujian fisis (absorpsi air dan densitas) dan pengujian mekanik (beban lentur dan kuat tekan). Dari hasil penelitian diketahui bahwa penambahan cangkang kerang dan serat gelas mampu membuat sifat fisis dan mekanik papan partikel lebih baik jika dibandingkan tanpa filler. Hasil dari pengujian sudah memenuhi semua standard ISO 8335, dengan nilai kuat lentur dan kompresi tertingginya masing-masing adalah 118,26 kgf/cm 2 dan 547 kgf/cm 2. Kata kunci-serat gelas, limbah bata ringan, limbah cangkang kerang, papan partikel

Research paper thumbnail of Degradation rate improvement of magnesium alloy AZ31 using plasma electrolytic oxidation as biodegradable implant

Nucleation and Atmospheric Aerosols, 2021

The aim of this research is to improve degradation rates of magnesium alloys AZ31 as biodegradabl... more The aim of this research is to improve degradation rates of magnesium alloys AZ31 as biodegradable implant using Plasma Electrolytic Oxidation (PEO) method. Magnesium alloys AZ31 is used as temporary biomaterials due to good mechanical and biocompatibility, however the degradation rate is weekness of the material. In this study, Plasma Electrolytic Oxidation was employed to grow oxide on surface by creating plasma using high voltage electrical source. This study to analyze the influence of sodium silicate concentration and oxidation time on morphology, mechanical property, and degradation rates on magnesium AZ31 alloys during PEO. The variations of sodium silicate concentration are 0.025, 0.035 and 0.045M with oxidation times of 5 to 15 minutes. Based characterisaion using XRD was found that there were two new compounds exist of the surface such as MgO and Mg 2SiO4. The results of SEM / EDX on the surface showed that the higher the concentration of sodium silicate and the oxidation time influence the pore diameter size become bigger and increase the thickness. In addition, based on AFM investigation, the surface roughness that was measured by micro vicker method has three times that was compared to untreated sample till peak condition while the concentration up to 0.045M and an increase in oxidation time of up to 15 minutes and then the hardness was decreased. In the rate of degradation evaluation using the weight loss method that the lowest degradation rate is during deposition using 0.025M sodium silicate concentration and 10 minutes oxidation time with a degradation rate of 2,89 mm / year.

Research paper thumbnail of Mechanical and Thermal Properties of Unsaturated Polyester/Vinyl Ester Blends Cured at Room Temperature

IOP conference series, May 1, 2017

Unsaturated polyester (UP) resin containing aromatic ring was blended with vinyl ester (VE) at wi... more Unsaturated polyester (UP) resin containing aromatic ring was blended with vinyl ester (VE) at wide range composition (10, 20, 30, 40,and 80 wt.%) using mechanical blending method. The blends were cured at room temperature using methyl ethyl ketone peroxide (MEKP) (4 wt.%) as catalyst initiator without the presence of catalystaccelerator. The effect of vinyl ester composition on theenhancement of mechanical and thermal properties of unsaturated polyester/vinyl ester blends was investigated.The polymer blends were characterized by Fourier Transform Infra Red (FTIR)spectroscopy, tensile testing, hardness testing, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). IR spectra showed UP and VE peaks. The curing copolymerization reactionoccurred at vinyl (C=C) bonds. The addition of vinyl esters enhanced mechanical and thermal properties. The UP/VE blends showed homogeneous morphology, transparent and copolymer thermoset blend.

Research paper thumbnail of Pengaruh Holding Time Pada Proses Post Heat, Laju Pendinginan Dan Waktu Perendaman Dalam Air Hujan Terhadap Kekerasan Dan Struktur Mikro Pada Pengelasan Gtaw Baja T91

Boiler merupakan suatu ketel uap yang menghasilkan energi uap panas. Salah satu bagian boiler ter... more Boiler merupakan suatu ketel uap yang menghasilkan energi uap panas. Salah satu bagian boiler tersusum atas pipapipa ataupun sambungan-sambungan lasan, pada pipa boiler terdapat material T91 yang masih asing digunakan dalam industri. Sehingga perlu di adakan penelitian lebih lanjut untuk memperoleh hasil yang maksimal dari pengelasan gas tungsten arc welding (GTAW) material T91. Penelitian ini bertujuan untuk meneliti pengaruh holding time pada proses post heat, laju pendinginan dan waktu perendaman dalam air hujan terhadap kekerasan dan struktur mikro. Dalam penelitian ini variasi post heat holding time 30, dan 60 menit serta laju pendinginan lambat dan udara, serta tanpa perendaman dan perendaman dalam air hujan kota Surabaya selama 7 hari. Hasil penelitian menunjukkan bahwa semakin lama waktu holding time dan semakin cepat laju pendinginan maka nilai kekerasannya akan semakin naik yaitu nilai kekerasan 230 HV pada weld metal. Perubahan nilai kekerasan setelah direndam dalam air hujan mengelami penurunan sekitar 5 HV.

Research paper thumbnail of Experimental Analysis on The Tensile Strength of Polyester Resin based Calcium Carbonate Powder and E-Glass Fibre Reinforced Composite

IOP conference series, Jun 26, 2019

Calcium carbonate powder is contained in the waste produced from processing limestone. Limestone ... more Calcium carbonate powder is contained in the waste produced from processing limestone. Limestone is used as an alternative substitute for organic fillers in polymer composites. The use of this waste can be a valuable resource as a replacement filler in polymer composites. The main purpose of this study is to reuse the waste materials calcium carbonate for composite materials. E-glass type woven roving is used as reinforcement and polyester resin was is as a matrix. In the present research, the addition of calcium carbonate waste powder in composites E-glass/polyester was investigated for tensile strength and density. In the hybrid, composite specimen of this study was prepared using hand lay-up technique. Tensile testing was carried out according to ASTM D368 standard. At first, calcium carbonate powder, glass fibre, and polyester were prepared in a specific volume and the specimens were prepared. Comparison filler plays an important role in producing the tensile strength of the composite. Thus, the fill ratio was considered as an experimental variable and were varied (2.5, 5.0, 7.5, and 10% by weight for calcium carbonate; 10, 12.5, 15, and 17.5% by weight for E-Glass. After testing was carried out, it is found that the strength of the material was increased as the volume of E-glass fibre increased.

Research paper thumbnail of Physical and mechanical properties of solid waste based LPDE/multi fillers composite

ADVANCES IN FRACTURE AND DAMAGE MECHANICS XX

Research paper thumbnail of Fabrication of high aspect-ratio metallic nanotube array with highly-ordered periodicity using HiPIMS

Journal of Alloys and Compounds

Research paper thumbnail of Design Analysis of External Airbag System at The Toyota Venza Vehicle

2020 6th International Conference on Computing Engineering and Design (ICCED), 2020

Airbag is technology in the automotive sector which was created to save the passenger from fatal ... more Airbag is technology in the automotive sector which was created to save the passenger from fatal risks in vehicle accident. Airbag are placed at the point of risk of passenger collision so that the impact load generated from this impact will be muted by airbags of the passenger. This research is designed to be able to perform rescue function not only for passenger, but also for vehicle itself. Because the placement of the airbags was placed on the bumper of vehicle, this part is installed with a high sensitivity sensor to be able to provide information to the system. So the airbags can expand before a impact occurs and the vehicle and its contents will be protected. ECU will send a signal to the squib inflator or also known as an igniter which is an electrical device in the form of a thin bridge cable, igniter will generate heat to burn propylene airbags which will produce nitrogen gas.