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OTOMASI PENGUKURAN DAN KONTROL PADA ALAT UJI MEKANIK BAHAN BERBASIS INSTRUMENTASI VIRTUAL Winarto, winarto; Santjojo, Djoko H.; Abdurrouf, abdurrouf
Physics Student Journal Vol 1, No 1 (2013)
Publisher : Department of Physics - Faculty of Science

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Abstract

Pengoperasian alat uji mekanik bahan yang dimiliki Jurusan Fisika UB masih dilakukan secara manual. Seringkali timbul perbedaan kecepatan yang berpengaruh terhadap tingkat akurasi dan presisi dalam pengukuran terhadap spesimen. Alat ini juga dilengkapi digital force gauge yang mampu mengukur gaya maksimal sebesar 50 N (yang digunakan maksimal sebesar 45 N). Tujuan dari penelitian adalah memodifikasi sistem penggerak pada alat uji mekanik bahan dengan implementasi kecepatan terkontrol yang mampu menarik beban hingga 45 N, membaca data keluaran dari digital force gauge dengan NI-VISA USB, dan mengetahui respon digital force gauge terhadap alat uji mekanik bahan yang telah dimodifikasi. Modifikasi dilakukan dengan menambahkan motor stepper yang dihubungkan ke hand wheel dengan roda gigi. Motor dikendalikan dengan program LabVIEW yang mengirimkan pulsa-pulsa digital ke driver motor stepper. Selain itu, program LabVIEW melalui interface NI-VISA USB digunakan untuk membaca data keluaran digital force gauge dan juga digunakan sebagai umpan balik. Hasil pengujian menunjukkan bahwa modifikasi alat uji mekanik bahan berhasil menarik beban hingga 45 N. Di sisi lain program LabVIEW tidak berhasil membaca keluaran digital force gauge.Kata kunci : Alat uji mekanik bahan, digital force gauge, LabVIEW.
PEMBUATAN APLIKASI UNTUK MENENTUKAN FASE DAN VISIBILITAS BULAN DENGAN MENGGUNAKAN ALGORITMA JEAN MEEUS Agus P., Arif; Rianto, Sugeng; Abdurrouf, abdurrouf
Physics Student Journal Vol 1, No 1 (2013)
Publisher : Department of Physics - Faculty of Science

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Abstract

Algoritma Jean Meeus merupakan salah satu dari sekian banyak algoritma yang digunakan dalam perhitungan astronomi. Salah satu penerapannya adalah dalam menentukan fase bulan baru (new moon) dan visibilitas bulan sebagai penanda masuknya awal bulan. Dengan menggunakan algoritma tersebut, dibuat sebuah aplikasi dengan bahasa pemrograman Java untuk membantu dalam memprediksi fase bulan baru dan visibilitas bulan untuk awal Ramadhan dan Syawal.
Perkiraan Dosis dan Distribusi Fluks Neutron Cepat dengan Simulasi Monte Carlo MCNPX pada Fantom Saat Terapi Linac 15 MV Azizah, Azizah; Abdurrouf, Abdurrouf; Bunawas, Bunawas
Physics Student Journal Vol 2, No 1 (2014)
Publisher : Department of Physics - Faculty of Science

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Abstract

Linac (Linear Accelerator) dengan energi di atas 10 MV akan menghasilkan neutron cepat karena terjadi interaksi antara foton dengan inti atom suatu material dengan nomor atom (Z) tinggi. Salah satu metode yang dapat digunakan untuk menghitung dosis neutron cepat yang dihasilkan oleh Linac adalah dengan menggunakan metode simulasi Monte Carlo. Salah satu aplikasi dari kode transport radiasi Monte Carlo yang dapat menghitung dosis dan fluks neutron adalah MCNPX (Monte Carlo N-Particle eXtended). Tujuan dari penelitian ini adalah untuk mengetahui dosis ekivalen dan distribusi fluks partikel neutron pada saat terapi Linac dengan metode simulasi Monte Carlo pada program MCNPX. Fantom disimulasikan menggunakan program MCNPX untuk menentukan dosis pada tiap organ dan ditribusi fluks pada fantom. Simulasi penyinaran dilakukan pada 4 sudut yaitu 0°, 90°, 180°, dan 270°. Hasil dari penelitian ini yaitu diperoleh dosis ekivalen neutron cepat paling tinggi terdapat pada permukaan tubuh yaitu dengan total sebesar 6,32 x10-11 mSv. Sedangkan dosis paling rendah terdapat pada kaki kiri bawah yaitu dengan total sebesar 4,77 x10-13 mSv. Fluks paling tinggi pada penyinaran sudut 0° terdapat pada daerah payudara yaitu sebesar 1,40x10-6 MeV/cm3. Fluks paling tinggi pada penyinaran sudut 90° terdapat pada bagian tubuh sebelah kiri fantom yaitu sebesar 1,60x10-5 MeV/cm3. Fluks paling tinggi pada penyinaran sudut 180° terdapat pada punggung fantom yaitu sebesar 9,00x10-6 MeV/cm3. Fluks paling tinggi pada penyinaran 270° terdapat pada bagian tubuh sebelah kanan fantom yaitu sebesar 1,40x10-5 MeV/cm3.   Kata kunci              : Linac, neutron cepat, simulasi Monte Carlo, MCNPX.
Pembentukan Titanium Nitrida (TiN) dengan Proses Nitriding pada Titanium Murni Menggunakan Plasma Densitas Tinggi Windajanti, Josephine Maria; Santjojo, Dionysius Joseph Djoko Herry; Abdurrouf, Abdurrouf
Jurnal 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 (776.563 KB) | DOI: 10.21776/ub.jrm.2017.008.02.5

Abstract

Pure titanium has been widely utilized in industry but its products suffered from low wear and erosion resistance. The plasma nitriding was selected as a tool to harden the pure titanium products but typically high temperature processing was required to attain high hardness. In the present study, high density plasma nitriding system was applied to make low temperature plasma nitriding at 723 K (or 450°C) for 14.4 ks (or 4 hours).  The average measured hardness reached to 624 HV.  This high hardness of plasma-nitrided pure titanium at low temperature was attributed to formation of fine TiN precipitates and nitrogen solid solution into vacancy sites in the HCP crystalline structure of titanium.
MICROSTRUCTURE AND PHASE TRANSFORMATION OF PURE TITANIUM DURING NITRIDING PROCESS BY HIGH DENSITY PLASMA J.M. Windajanti; D.J.D.H. Santjojo; Abdurrouf Abdurrouf
Jurnal Sains Materi Indonesia Vol 18, No 3: APRIL 2017
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (346.83 KB) | DOI: 10.17146/jsmi.2017.18.3.4115

Abstract

Low temperature nitriding process at a temperature of 450 °C has been carried out in order to increase the surface hardness of pure titanium. The plasma nitriding process was utilized by high density RF-DC system with an addition of a hollow cathode device. The plasma was generated by RF generator with the frequency of 2 MHz and attract directly to the cathode plate by high voltage DC bias of -500 to -600 V. The plasma of N2/H2 gases with a flow rate of 160/40 mL/min in gas pressure of 75, 50, and 30 Pa was used in nitriding process for 4 h and 8 h. The occurrence of phase transformation of –Ti to w-Ti triggers the formation of TiN as a nitride layer. The formation of TiN and the diffusion of nitrogen into a titanium matrix can increase the surface hardness of pure titanium up to 792.0 HV.
Effect of Sterculia quadrifide Extract R.Br. Against Free Radical In Liver Organs Oreochromis niloticus Due to Heavy Metal Pollution Janes Bastian Selly; Abdurrouf Abdurrouf; Unggul P. Juswono
Natural B, Journal of Health and Environmental Sciences Vol 3, No 2 (2015)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (805.288 KB) | DOI: 10.21776/ub.natural-b.2015.003.02.11

Abstract

Sterculia quadrifida R.Br. is known with the name of Faloak. It is a plant whose bark has been containing several natural antioxidant compounds. Research shows that antioxidant compounds of Faloak extract can reduce free radicals content in liver organ of nila fish (Oreochromis niloticus) that is contamined by metals such as Pb, Cd and Hg. The concentration of metals is directly proportional with free radicals content of the organ, but free radicals content is inversely proportional with the concentration of faloak extract. Result of research indicates that faloak concentration of 16,00mg/mL is the most effective concentration in reducing free radicals content in liver organ of nila fish. Type and content of free radicals in the organ are identified with Electron Spin Resonance (ESR) test. 
2D Imaging Technique Electrical Impedance Distribution on Liquid with Paired Method and Using EIDORS Software Ahmad Zarkasi; Abdurrouf Abdurrouf; Didik Rahadi Santoso
Natural B, Journal of Health and Environmental Sciences Vol 4, No 1 (2017)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (874.679 KB) | DOI: 10.21776/ub.natural-b.2017.004.01.5

Abstract

This paper discusses the 2D imaging technique of the electrical impedance distribution in the liquid by using the principles of Electrical Impedance Tomography (EIT).  A tomographic technique used in the imaging process is a adjacent or neighbor method, with input data obtained from measurements of the electrical potential at the boundary measuring object. Measurement data is reconstructed using open source software, i.e. EIDORS, which in image reconstruction using the principle of Finite Element Method (FEM). As a comparison on the results of image reconstruction by EIDORS, here used Boundary Data Simulation (BDS) were obtained from the same measurement data. Based on the results of the 2D images that have been obtained, it is evident that the techniques and imaging methods that have been used are able to show the distribution of electrical impedance value of the measuring object and have a good agreement with the results of BDS.  
Analysis of Experimental Results Measurement of Electric Impedance Value on Liquid with Injection Flow on Parallel Plate Gianita Anastasia Salamena; Abdurrouf Abdurrouf; Didik Rahadi Santoso
Natural B, Journal of Health and Environmental Sciences Vol 4, No 1 (2017)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (253.578 KB) | DOI: 10.21776/ub.natural-b.2017.004.01.4

Abstract

This paper discusses the results of experimental measurement of the electrical impedance of liquids in parallel and perpendicular position to the direction of current injection. Experiments carried out on three different types of liquid i.e. distilled water, mineral water, and milk. Each liquid is placed in a container box with volume of 2,5cm x 2,5cm x 2,5cm. The electrode is located in the middle of the upright side of the container, forming two pairs of parallel plates, where one pair of parallel plate will serve as the current electrode. Current signal frequency range used in this experiment is 1Hz-500Hz. Experimental results obtained some things such as each liquid has a different electrical characteristic, distilled water has much larger electrical impedance compared to the mineral water and milk. Area of the electrode affects the measured impedance values on each liquid; the larger area of the electrode will decrease impedance value. The position of the electrode against the direction of flow injection showed the difference in impedance values measured, where the impedance measured at liquid injection electrode direct current is greater than the value of the impedance measured at liquid electrodes perpendicular injection current.
Determination of Polystyrene Layer Thickness and Zinc Phthalocyanine (Znpc) with Modified Sauerbrey Equations and Scanning Electron Microscope (SEM) Lalu A Didik; Eka Rahmawati; Fadli Robiandi; Susi Rahayu; Abdurrouf Abdurrouf; Djoko H. Santjojo; Setyawan P. Sakti; Masruroh Masruroh
Natural B, Journal of Health and Environmental Sciences Vol 2, No 4 (2014)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (548.641 KB) | DOI: 10.21776/ub.natural-b.2014.002.04.6

Abstract

The thickness measurement of PS thin films on QCM surface and ZnPc layer on QCM/PS using Sauerbrey equation and Scanning Electron Microscope (SEM) has been investigated. Calculation result using a modified Sauerbrey equation show the thickness of PS layer and ZnPc one are 0,45 μm and  0,0676 μm respectively. Additionally the thickness measurement by using SEM shows the thickness of PS  layer is 5,33 μm and the  thickness of ZnPc layer is 10,44 μm. The differences thickness between Sauerbrey equation and SEM topograph is due to layers porosity. The topography of thin films produced by the secondary electron beam scanning allows to get a magnification of SEM image so that it can be measured directly. While the thickness calculation using the Sauerbrey equation is based on the change in the resonance frequency of QCM.
Effects of Adhesives on Quality Biomass Briquette Abdurrouf Abdurrouf; Istiroyah Istiroyah; Gancang Saroja
Natural B, Journal of Health and Environmental Sciences Vol 1, No 1 (2011)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (559.209 KB) | DOI: 10.21776/ub.natural-b.2011.001.01.1

Abstract

Production of briquettes from organic waste with starch as an adhesive, has been done. The briquette's quality is improved by (i)  the milling of organic waste is conducted in dry phase, and (ii) the mixing between organic waste and starch as an adhesive is carried out on raw phase. This study shows that the best briquette was obtained when the ratio of organic wastes - starch was 10:3. In such composition, mass of the produced briquette was more than 50% of the mass of organic waste. For more improvement, it is necessary to find a better pressing and drying technique. It is also need to make briquette in large numbers to improve its characterization.