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Sonief, Achmad As'ad
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Boron Doped Graphene 3-Dimensi untuk Superkapasitor Kapasitas Tinggi Sari, Nurlia Pramita; Sonief, Achmad As'ad; Ching, Yuan Su
Rekayasa Mesin Vol 8, No 2 (2017)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (433.154 KB) | DOI: 10.21776/ub.jrm.2017.008.02.1

Abstract

Chemical doping is an effective approach to improve the property of carbon material. In this study boron doped graphene with 3D structure used as the electrode was investigated. Boron doped graphene was prepared through freeze-dried process followed by pyrolysis of graphene oxide (GO) with three types of chemical substances; boron oxide, boric acid, and boron powder in an argon and hydrogen atmosphere at 1000 C for 3 hours. The difference of chemical composition generated a different percentage of boron bond with GO. The results shows that the highest electrochemical performance was found in graphene samples with the addition of boric acid (BA) 86 F/g, followed by boron oxide (BO) 59.2 F/g, and boron powder (BP) 2 F/g. It can be caused by boron concentration bound with graphene. The higher concentration of boron could be increased the electrochemical performance due to better of ion movement.
Pengaruh Waktu Perlakuan Kalium Permanganate (KMnO4) Terhadap Sifat Mekanik Komposit Serat Purun Tikus (Eleocharis Dulcis) Kosjoko, Kosjoko; Sonief, Achmad As'ad; Sutikno, Djoko
Jurnal Rekayasa Mesin Vol 2, No 3 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (162.516 KB)

Abstract

The combination between treatment time of the addition and directon fiber orientation wasused to get maximum mechanical properties of Purun Tikus fiber composites. The purpose ofthis study was to construct composite of polyester matrix and Purun tikus natural fiber by mixing2 % KMnO4 with 1 liter aquades for 15 minutes and 30 minutes. It is applied to determine tensile strength and flexural strength. The variation of volume fiber fraction are 20%, 30%, and 40%. The directon of Purun Tikus fiber are 0 and 90%, and the polyester matrix type 157 BTQN with1% concentration of MEXPO hardener. The dimension of tensile specimen refered to standart ASTM D638-03. The flexural strength was obtained trough bending test based on ASTM 790-03. The combination of these 2 variables can improve interfacial adhesion between fiber andmatrix. The highest tensile strength was 2% KMNO4 for 15 minutes of natural fiber composites Purun Tikus with volume 40@ about 55.54 N/mm2. The variation of 2% KMnO4 for 30 minutes the volume fraction of 40% was 41.07 N/mm2. The obtained of variation without KMnO4 treatment and fraction volume 40% about 40.03 N/mm2 The highest flexural strength of the composite fiber Purun tikus in the variation treatment 2% KMnO4 for 15 minutes with the volume fraction 40% was 119.70 N/mm2, for 30 minutes the fraction volume 40% was 80.88N/mm2, and the fraction volume 40% without treatment was 62.66 N/mm2.Keywords:purun tikus fibers, kalium permanganate, polyester, tensile strength & amp; flexuralstength
Pengaruh Temperatur Karbonisasi terhadap Mikrostruktur dan Pembentukan Kristal pada Biokarbon Eceng Gondok sebagai Bahan Dasar Absorber Gelombang Elektromagnetik Radar Imammuddin, Azam Muzakhim; Soeparman, Sudjito; Suprapto, Wahyono; Sonief, Achmad As'ad
Rekayasa Mesin Vol 9, No 2 (2018)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (479.939 KB) | DOI: 10.21776/ub.jrm.2018.009.02.10

Abstract

Radar Absorbing Materials (RAM) or radar absorbing materials of radar electromagnetic waves are materials used to reduce or eliminate radiation of radar electromagnetic waves in order to avoid reflection of waves. At this time the development of RAM research leads to materials derived from nature. Some materials derived from nature that has been used as RAM such as rice husk, bamboo, coconut shell, coconut husk, wood fiber, and wood flour. In this study, eichornia crassipe is made into biocarbon or activated carbon for use as a base material for RAM. Carbonization is one way to transform water hyacinth into biocarbon or activated carbon. The method used in this research is Experimental Research. The independent variables of this research are carbonization temperature starting from temperature 500oC, 600oC, 700oC, 800oC, 900oC and 1000oC. The results showed that the higher the carbonization temperature, the more open pores will be with 2 μm diameter at 1000oC, and the higher the carbonization temperature than the percentage of carbon crystal formed higher with the value of 14% at temperatures 900oC and 1000oC. The biocarbon structure of eichornia crassipe is crystalline and amorphous making it suitable for use as RAM material.
Karakterisasi Kekuatan Mekanik Komposit Berpenguat Serat Kulit Waru (Hibiscus Tiliaceus) Kontinyu Laminat Dengan Perlakuan Alkali Bermatriks Polyester Nurudin, Arif; Sonief, Achmad As'ad; Atmodjo, Winarno Yahdi
Jurnal Rekayasa Mesin Vol 2, No 3 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (345.461 KB)

Abstract

The purpose of this research is knowing the tensile strength and bending strength of polyester reinforced waru (Hibiscus tiliaceus) fiber composites with alkali treatment and variations in fiber orientation so we get the proper utilization of its strength properties. This composite material may be can replace fiberglass are expensive as reinforcement material in the process of making the ship’s hull.The method is performed by conducting alkalizationhibiscus fiber skin with 5% NaOH solution for 2 hours. In the manufacture of test specimensmade of composite test variations using four layers of fibers and fiber orientation angle is0o/45o/-45o/0o ; 45o/0o/0o/-45o ; 45o/0o/-45o/0o. Test object is made by hand lay-up and with anemphasis manually using a mold and press. Matrices are used polyester resin 157 BTQN and catalyst type MEKPO a concentration of 1%. Photo of specimen fracture was observed with amacro image observation. Mechanical properties are obtained from tensile tests and bending tests.The results showed that tensile strength and bending strength influence by alkali treatmentof NaOH 5%. Polyester reinforced waru fiber composite specimens with 5% NaOH treatment for2 hours is the same strength of attraction between the fiber direction angle of 0o/45o/-45o/0o is66.14 N/mm2; 45o/0o/0o/-45o is 66 ,46 N/mm2; and 45o/0o/-45o/0o is 66.78 N/mm2. Tensilestrength without alkali treatment is 49.13 N/mm2 on the fiber orientation direction 0o/45o/-45o/0o. The maximum bending strength obtained is 179.78 N/mm2 on the fiber orientation angle 0o/45o/-45o/0o with 5% NaOH alkali treatment. Bending strength of the lowest found in thedirection of fiber orientation angle 45o/0o/0o/-45o without alkali treatment is 134.43 N/mm2.Keywords: composite, waru fiber, alkalization, fiber direction
Pengaruh Parameter Proses Freis Terhadap Kekasaran Permukaan Baja Karbon Fasa Ganda Arifin, Nur Mohammad; Sonief, Achmad As'ad; Atmodjo, Winarno Yahdi
Rekayasa Mesin Vol 2, No 3 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (634.518 KB)

Abstract

Dual phase is a new structure at low or medium carbon steel. The structure is obtained from the heating of low or medium carbon steel in the region α + γ (temperatures between A1-A3), then follow by holding process within a certain time and cooled quickly (quench) in water,brine or oil. The result has a microstructure of martensite and ferrite as well as a few otherstructures. The steel usually has high tensile strength, good elongation and there is no discontinuity yield. The problem is how the influence of parameters milling process on surface roughness the dual phase carbon steel The purpose of this study was to determine the outcome Freis CNC cutting conditions due to the formation process of double and tempering phase that begins with the process of forging (forging) on carbon steel .This study used AISI1045 steel Ø16mm x 150mm diameter, which was forged at a temperature of 950oC-900oC to form a rectangular cross section with a size of 10mm x 16mm x 180mm. Dual-phase heating was continued at a temperature of 770ºC, arrested at 90 'and cooled rapidly in oil , followed by atempering process 600⁰C/30 '. The process of cutting was done by cutting finishing with feeding 0.12; 0.14; 0.16 mm / put and depth of cut 0.4; 0.6; 0.8 mm while roughing cuts by feeding 0.2;0.4; 0.6 mm / put and depth of cut 1.2, 1.4;a1.6amm .The result Depth of cut can affect the deflection. The deflection could be increased by increasing the depth of cut. The results obtained increase the level of surface roughness. On the depth of cut 0.4 mm with feeding 0:16mm / put the value obtained average roughness Ra 0.64 μm, including group N6 roughness when compared with 0.8 mm depth of cut with the same feeding value of average roughness Ra 1.08 μm including N7. Surface roughness increased by feeding could affect the feeding of 0.12 mm / put and 0.16 mm / put, 0.2 mm / put and 0.6 mm /put because the distance from the cutting peak roughness increases, so the roughness of the rough and the process of finishing cuts on carbon steel dual phase is more subtle than on the untreated carbon steel with the same cutting parameters.Keywords: forging, dual phase (dual phase), the cutting parameters
Chatter Vibration Comparison Between Normal Helix Angle and Variable Helix Angle in End Milling Process Based on Spectrum Analysis Sonief, Achmad As'ad; Fauzan, Arda Nur; Azlan, Fachry; Bashori, Muhammad Aziz
Jurnal Rekayasa Mesin Vol 11, No 3 (2020)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2020.011.03.25

Abstract

Chatter vibration in machining processes is often found in cutting processes which will decrease the machining efficiency and the surface quality of the products. Chatter is a relative vibration of the cutting tool and workpiece caused by the fluctuation of cutting force that is concerned to be a self-excited vibration. The variable Helix Angle Cutting tool which has pitch angle variation will also inflict different tooth passing frequencies on the flute that stand contiguous and trim the resonance frequency. This research aims to compare chatter vibrations that occurred between Normal Helix Angle and Variable Helix Angle cutting tool based on spectrum analysis on cutting parameter variety (depth of cut; rotation speed; feed rate milling). The outcome is spectrum analysis can detect the chatter phenomenon, measure the natural frequency (38-42 Hz), and also compare chatter vibrations between two tools appropriately.