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Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains
Published by Universitas Riau
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Core Subject : Engineering,
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Articles 3,145 Documents
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Pengaruh Suhu Reaksi Dan Kecepatan Pengadukan Pada Sintesa Hidroksiapatit Dari Kulit Kerang Darah (Anadara Granosa) Dengan Metode Hidrotermal Suhu Rendah Dewi Indah Pratiwi; Ahmad Fadli; Zultiniar Zultiniar
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

Hydroxyapatite (HA) is a ceramic material that widely used for bone implants as biocompatible and bioactive properties. Sea shells can be used as a source of calcium to produce hydroxyapatite. The purpose of this research was to determine the effect of rate stirrer and the reaction temperature on the synthesis of hydroxyapatite from sea shells with a low temperature hydrothermal method. The procedure was started with calcining sea shells into CaO at a temperature of 1000oC for 24 hours. Then 55.63 g of NH4H2PO4 was dissolved in 600 mL of water and 45.91 g of CaO was added into the solution at temperature variation of 70°C, 80oC, 90oC and stirring rate of 200 rpm, 250 rpm, 300 rpm until it forms a paste. The paste was dried in an oven at 120oC for 15 hours. Then the dried paste was crushed and calcined at a temperature of 900oC for 1 hour. The results showed that the size of hydroxyapatite crystals at 70°C is 63.43 nm, while the crystal with the size of 52.48 nm obtained when the temperature was increased to 90oC. The rate of stirrer of 200 rpm, the crystal with the size of 62.92 nm obtained, it decrease to 52.48 nm when the stirring rate increased 300 rpm. FTIR analysis showed that the hydroxyapatite is formed at the calcination temperature of 900°C. HA at a reaction temperature of 90oC with the stirring rate of 300 rpm to meet the standards as a bone filler (bone filler) synthetic.  Keywords: Crystallinity, Hydrothermal, Hydroxyapatite and Sea Shells
Pre-Treatment Jerami Padi Menggunakan Proses Organosolv Dengan Variasi Konsentrasi Pelarut (CH3OH) Dan Waktu Pemasakan Siregar, Yohana; Yenie, Elvi; Daud, Syarfi
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
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Rice straw is one of  agricultural waste products which has not to be used in huge area. Rice straw is usually used for some purposes, such as roofs and fodder. Biomass or rice straw is composed of three main components, namely cellulose (34.2%), hemicellulose (24.5%) and lignin (23.4%). Delignification aims to separate lignin from other compounds contained in the biomass by using an organic solvent which is methanol.  Due to this solvent is easier to obtain, more friendly to enviroment, and the solvent could be recovered back. Lignin contained in rice straw could potentially be used as a source of alternative materials in various industries, the one is adhesive industry. The aims of this research are to study the effect of the concentration of solvent and cooking time to the achieve the lignin. The study was conducted with a cooking time of  60; 120; and 180 minutes, the concentration of methanol 65; 75; 85; and 95 % w/w. The process steps in this research include size reduction by using mixing, cooking (delignification) using methanol, then washing and filtering stages. In this research, the lignin yield best at 13.6 % which was obtained at cooking time of 120 minutes with 65 % methanol concentration and the lignin content of 20.5 % w/w. Lignin was analyzed functional groups with the Fourier Transform Infra Red spectroscopy (FTIR ) .  Keywords: Cooking, Delignification, Fourier Transform Infra Red spectroscopy (FTIR), Lignin, Organosolv, Rice Straw
Pengaruh Pencucian Membran Ultrafiltrasi Menggunakan Surfactan Dan NaOH Pada Proses Penyaringan Air Terproduksi Sonny Wijaya; Syarfi Daud; Bahruddin Bahruddin
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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One of water treatment technology that can be used for treat produced water is membrane technology. The most of challenging in membrane technology is fouling. The objective of this research are to study influence of ultrafiltration membrane washing to flux recovery and removal resistance by using surfactant and NaOH for treat produced water. Membrane that to be used on this research is membrane ultrafiltration with pore size between 0.1500 until 0.0014 micron and using capillary module configuration. The method that to be used is current-cross flow for filtration proses with filtration time 180 minutes with pressure in 0.2 bar, 0.4 bar, 0.6 bar and concentration of cleaning agent surfactant and NaOH in 1.5%, 2.0% and 2.5% by using counter-cross flow with pressure 0.8 bar and time for washing in 30 minutes. The highest washing effectiveness rate of 69.53% obtained by using surfactant 2.5% and filtration pressure 0.6 bar, the highest leaching efficiency based on flux recovery value is 99.32% and 99.65% for removal resistance obtained by using surfactant 2.5% and filtration pressure 0.2 bar.  Key words: flux recovery, fouling, produced water, removal resistance, surfactant, ultrafiltration membrane
Sintesis Dan Karakterisasi Hidroksiapatit (HAp) Dari Kulit Kerang Darah (Anadara Granosa) Dengan Proses Hidrotermal Khoirudin, Mukhlis; Yelmida, Yelmida; Zultiniar, Zultiniar
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

Hydroxyapatite Ca10(PO4)6(OH)2 is a material that recently used as a filler and coating for bone and teeth implant. It is used as an implant because it has a good bioactive and biocompatible characteristics. HAp synthesis can be made by using material which is rich of CaCO3 like blood cockle shell (Anadara granosa) (98,7 %). In this research, blood cockle shell whichhas calcium source was synthesized to HAp by hydrothermal process. The size of blood cockle was varied (60, 100, 200 mesh) and reaction duration (16, 20, 24 hours). The outcome of synthesis was characterized by using with FTIR, XRD, SEM-EDX. From FTIR, it showed that hydroxyapatite was formed with the presence of the peak from ion PO43- dan OH. The highest peak was obtained from 200 meshes of particle size for 24 hours. XRD results showed the peaks of hydroxyapatite diffraction pattern with HAp standard at angle 2θ is 10.8322°, 21.7774°, 25.9091°, 28.1308°, 34.1252° with JCPDS hydroxyapatite standard. The form of crystal was hexagonal. SEM-EDX showed the morphology size which was 10µm - 100µm range and 1,99in Ca/p ratio.  Keywords: Blood Cockle Shell,Synthesis,Hydroxyapatite, Hydrothermal Method.
Menentukan pH Optimum Di DO Stage Untuk Mengurangi Konsumsi CIO2 Pada Proses Pulp Bleaching Di PT. RAPP Winarto Tarigan; Chairul Chairul; Maria Peratenta Sembiring
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
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Abstract

The process of bleaching is a chemical process that is used on chemically treated pulp and mechanical pulp aimed at increasing degrees of brightness according to the expected target. The purpose of the bleaching process are: increasing the brightness, maintaining brightness stability, removing dirt and unwanted components and maintain the physical strength of the pulp. Pulp bleaching process has several stages of the first delignification (D0), Extraction Peroxide (EP), and Last Delignification (D stage). There are few process variables having an effect on the bleaching process, one of which is pH.  At  first delignification process (D0) with the kappa factor 0.25, the process temperature  about 75 oC for 1 hour, the expected optimum  end pH is 3.5 to 4.0. In these conditions will produce pulp with 65.42% ISO brightness, and after going through the process of extraction Peroxide (EP) for 90 minutes will produce a pulp with a kappa number a low of 2.63. So after going through the process in Last Delignification (Dstage) will have the lowest consumption of chlorine dioxide. Overall pulp with a final pH Do stage 3.5 to 4.0 Chlorine dioxide is consumed as much as 133.6 ml. Keywords: pH, Bleaching, Chlorine Dioxide
Aplikasi Spectrum Analyzer Untuk Menganalisa Frekuensi Sinyal Audio Menggunakan Matlab Wahyudi, Septian Tri; safrianti, Ery; Rahayu, Yusnita
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
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In this study, the authors implement an application Spectrum Analyzer used to examine the frequency response of the human voice. This application begins with making the function of the Fast Fourier Transform (FFT), which calculates the value of the amplitude of a wave file. Then the manufacture equalizer and normalization adjusts the value of the highest amplitude of each spectrum to be more easily studied. Spectrum Analyzer application is built using MATLAB programming language. From the test results, the human voice is in the frequency range of 300 -3400 Hz and a human voice shrill has higher frequencies then bass, By using sound recorder application that already include in the operation of windows, the audio signal will be at the input. The audio signal that we will process here is the type of audio signal stereo. Stereo signals having a phase of R and L which produces the dominant voice on the left or right.  Keywords : Fast Fourier Transform (FFT), the audio signal, spectrum analyzer
Analisis Rancang Bangun Pembangkit Listrik Dengan Mesin Sepeda Motor Dengan Penggerak Mula Terkendali
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
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Abstract

Utilization of DC motors for moving the mechanical drive in place of the gas starter (prime mover). Which controlled by a controller to regulate the movement of the voltage controlled DC motor power window. Change of generator output voltage will read the sensor voltage Vout generator converted to a voltage which in this Vdc. Voltage read ATMEGA8 Mickrokontroler IC by using the ADC will determine the movement of the motor as the controller of gas, if the voltage is less than 220 V  to its minimum voltage of the motor which has coupled on gas prime movers will rotate clockwise so the motor is pulling gas to reach the expected speed of the generator and its reverse in case of overspeed which causes more stress then the generator will rotate anti-clockwise so that the gas will drop to adjust the speed generator. So, rotation of DC motors forward and reverse and at a predetermined voltage level is normal voltage 220 -230 V motor will stop, and will hold the gas engine driving the generator speed will be maintained so long as the voltage under normal conditions 220-230 V. . Keywords: DC Motor, DC Motor Driver, microkontroller ATMEGA8, Vdc Power Supply.
Analisis Daerah Rawan Longsor Berbasis Sistem Imformasi Geografis (Studi Kasus : Kabupaten Lima Puluh Kota, Sumatera Barat) Jeffi Annisa; Sigit Sutikno; Rinaldi Rinaldi
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
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Lima Puluh Kota is one of the regency in West Sumatera Province that prone to landslide, particularly when the rainfall intensity is high. Therefore, the research is conducted to determine the location that prone to landslide in Lima Puluh Kota regency in order to prevent the risk that potentially leads to disaster. The model that was applied to determine the prone landslide location is Indeks Storie, which would be treated in Geographic Information System’s program. Before that overlay process has been done, which was overlaying some of parameter maps (map of slope, map of soil types, map of rainfall, and map of land use) and marked the score in eachcriteria from the parameter maps. Based on the level classification analysis of Arifin S, et al (2006) Lima Puluh Kota regency is on the very low, low, and medium level of prone to landslide. This condition is contradicting with the actual fact. Based on level classification analysis of Nugroho, J.A, et al (2009) there are areas in Lima Puluh Kota that have very low, low, medium, high, very high level of prone to landslide which close to the actual fact. From the analysis in this map, the prone to landslide level in Pangkalan Koto Baru is very high, Sarilamak and surrounding areas have medium and high prone to landslide level, Harau subdistrict has high prone to landslide level, Gunung Omeh subdistrict has medium prone to landslide level.Keywords: SIG, Prone to landslide
Evaluasi Keterlambatan Proyek Pembangunan Gedung Kantor Dinas Pekerjaan Umum Provinsi Riau Doli Patumona; Hendra Taufik
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

Completion time determination project management, is among the first and the most important in the process of planning because it can be the basis of the whole planning. Project completion delay means overhead raise due to the elongation of construction time. it can inflict financial losses due to the possibility cost penalty of delays. The project of Regional Office of Civil Work Department is having a delay of 28 days from its contract duration. Final contract work at 80 weeks can only be fulfilled at 99,83% from 100% planned. Hence, the project is having a 0,17% delay. Project delay should be resolved by increasing the pace of construction on the remainingworks. Construction acceleration can be done by means of overtime work, equipment and workers addition, and shift system. The analysis conducted focuses on works that are on the critical path after the third addendum. From the analysis, it can be obtained that the cost due to delay stands at Rp.5.891.016.348,00. The cost that the contractor will spend by accelerating the works are Rp. 4.637.245.856,41 from overtime work alternative, Rp. 329.443.076,99 from equipment and workers addition alternative, and Rp. 1.713.439.777,73 from shift system alternative.Keywords: construction delay, construction cost, duration shortening, overtime work, equipment and workers addition, shift system.
Analisa Variabel Kegagalan Kontraktor Di Kota Pekanbaru Dalam Proses Evaluasi Pengadaan Barang Dan Jasa Pemerintah Secara Elektronik (E- Procurement) Ni Wahyu Dyah; Ryan Tri Komara; Sri Djuniati
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 2, No 2 (2015): Wisuda Oktober Tahun 2015
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Abstract

E-procurement is a process of procuring goods and services which is done electronically (internet/web based). One of the steps worth noted in construction project is the process ofcontractor appointment. Usually, such process is conducted through the auction of services and goods procurement. The auction is currently regulated in Presidential Regulation of 2012Number 70 about the second amendment of Presidential Regulation of 2010 Number 54 about Procurement of Government Services and Goods. In accordance to the regulation, this research aims to identify failure variables that can affect the process of evaluation for construction services auction in government owned project especially in Pekanbaru, Riau. Data in thisresearch is obtained from interview with the Head of ULP and LPSE of Riau Province and also secondary data obtained from LPSE of Riau Province’s website that comprise of documents regarding the implementation of the auction especially in road and pavement constructionservice on 2011, 2012 and 2013. The method used to process the data is manual process using software aid of Microsoft Excel, pie chart and bar chart. According to the result of the analysis conducted on auction for road and pavement construction service between 2011 until 2013, it can be obtained that the biggest percentage of 44 % during 2011 is for administration phase, the dominant factor of contractor failure because they were not uploaded document of demand.In 2013, the biggest percentage of 48 % of the contractor failure caused by technical problems inconstruction method and where in 2013 with the same the dominant factor of contractor failure increased to 50 %.Keywords: E-procurement, failure factor, auction, services and goods procurement system

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