257 research outputs found

    COVER

    No full text

    PENINGKATAN KEKUATAN TARIK SAMBUNGAN SINGLE V-GROOVE BAJA ST37 DENGAN VARIASI ARUS PENGELASAN SMAW

    Full text link
    Welding and casting processes have become an important focus in the development of industry 5.0. In improving welding efficiency, increasing the number of tests on many variables is the first step in optimizing production. Welding optimization aims to find the best solution and result in a production process, it takes a lot of welding experimental data to be able to compare it. The Shielded Metal Arc Welding (SMAW) is becoming very common in all industries. SMAW has several variables that can affect welding results, one of which is the electric current used. This study aims as an effort in the current industrial development is to present data on the effect of SMAW welding electric current on its tensile strength for optimization. In this study, the mechanical strength tested was tensile strength and current susceptibility used was 80 to 140 Ampere commonly used using ST-37 Steel. The highest maximum loading value occurred in the sample with a current of 80 A of 72.78 kN. However, the highest maximum stress, fracture, and yield occurred in the sample with a current of 140 A of 734.66; 594.28; 558.29 MPa

    STUDY OF INFLUENCE TIME IN THE IMPROVEMENT OF NICKEL CONTENTS ON LIMONITE PROCESSING USING NAOH

    Full text link
    Logam nikel didominasi oleh bijih sulfida, namun 70% sumber nikel dunia adalah bijih laterit, yang hanya menyumbang 40% dari output nikel dunia. Menanggapi kenaikan permintaan dan penurunan deposit nikel sulfida, pemurnian nikel bijih laterit dan teknik produksi hidrometalurgi untuk bijih laterit semakin intensif. Silikon dapat diekstraksi dari bijih nikel laterit dengan NaOH. Berbagai penelitian menunjukkan bahwa metode ini dapat meningkatkan kandungan nikel dari residu pelindian, memungkinkan limbah sisa untuk digunakan kembali dan mengurangi dampak lingkungannya. Penelitian ini bertujuan untuk mengetahui apakah mekanisme pengendapan dapat secara efektif memisahkan nikel dan kobalt dari pengotor lainnya. Limonit dilindi menggunakan larutan NaOH dengan konsentrasi 60 g/L. Durasi pelindian bervariasi antara 30, 60, 90, dan 120 menit. Pengaruh NaOH sebagai larutan pelindian diselidiki dengan pengujian XRD dan AAS. Hasil dari analisis XRD menunjukkan proses pelindian menggunakan NaOH membentuk fasa nikel dan kobalt oksida dan hidroksida dari goetit dan NaOH, dengan fasa lain pada residu pelindian terbentuk seiring dengan bertambahnya waktu pelindian. Pengujian AAS menunjukkan nilai perolehan nikel negatif yang dapat dihasilkan oleh kontaminan pada sampel awal, pelarutan ion nikel, dan kopresipitasi, dimana ion nikel diserap ke dalam fase besi hidroksida. Selain itu, uji AAS juga menunjukkan nilai perolehan kembali kobalt pada waktu pelindian 30 menit adalah 1,41%, yang berarti bahwa waktu tersebut adalah waktu optimum untuk pelindian kobalt. Sedangkan waktu yang melebihi 30 menit dapat menurunkan kadar kobalt karena pengenceran ulang dan pengendapan bersama

    STUDI EMISI SPEKTRA PADA SINTESIS PEMBAKARAN METAL ALUMINIUM DALAM PLASMA-UDARA

    Full text link
    Research on emission spectra of metal combustion at temperatures above the boiling point of Al has been successfully carried out. This method can be used as a qualitative characterization of the presence of elements or compounds involved in the combustion process. Recording of emission spectra data was carried out during the process of burning Al powder with oxygen O in an air plasma flame at atmospheric pressure. The burning characteristic of Al was detected at the peak intensity of the wavelength λAl = 396 nm, and the reaction products of AlO with the peak intensity of the wavelength λ­AlO were 471, 489 and 512 nm, respectively. The absolute temperature of the plasma flame black body was 5660 K based on the highest peak intensity λAlO = 512 nm. The increase in emission intensity was quite significant when Al was started to be injected at 1.25 seconds, followed by an unstable plasma form. The steady state of the plasma flame indicates a full reaction in the vapor phase of AlO(g) in the form of Al sub-oxide and alumina before condensing on the outer surface area of ​​the plasma. High temperature thermal plasma-air can increase the homogeneity of the atomization process of particles into gaseous vapor which is an important initiation where nanoscale AlO particles begin to form

    ANALISIS PERFORMA TURBIN ANGIN VAWT (VERTICAL AXIS WIND TURBINE) TIPE HYBRID SAVONIUS DARRIEUS NACA 4712

    Full text link
    A wind turbine is a device that converts wind energy into mechanical energy to produce electric power. Wind turbines have a simple working principle, which is to convert wind energy into mechanical energy in the windmill, then the rotation of the turbine0makes the rotor on the generator rotate and generate electricity. There are 2 types of wind turbines: vertical axis wind turbine and horizontal axis wind turbine. This study aims to determine the performance of the medium-scale VAWT hybrid savonius darrieus NACA 4712 wind turbine. The hybrid wind turbine is a combination of savonius and darrieus wind turbines to increase efficiency by utilizing the drag of the savonius turbine and lift force from the darrieus wind turbine. This study used an experimental method. The fan is used to vary the wind speed. The wind speed used ranges from 5, 5.5, 6, 6.5, 7, 7.1,7.2,7.3 m/s. This savonius darrieus hybrid wind turbine can produce efficiency of 0.037 at wind speed of 5 m/s with an initial torque of 0.088 N/m. The maximum rotation in this hybrid turbine study 118 Rpm was obtained at a wind speed of 7.3 m/s

    ANALISIS ALIRAN MASSA UAP PADA KATUP KONTROL UREA (UREA GLOBE CONTROL VALVE) DI UNIT PRODUKSI UREA PABRIK 1B PT PETROKIMIA GRESIK

    Full text link
    In a process, industrial plants have several tools that require steam to help run the processing of a material. For the heating process, PT. Petrokimia Gresik requires steam. Sometime the steam leak during the process, so it reduces the productivity of this industry. For that reason, the purpose of this calculation is to find out the steam loss during the process, especially in urea globe control valve (PV-723, PV-726, PV-735). The result show that the upstream pressure and temperature at PV-723 are 21 kg/cm2G and 307 oC, upstream pressure and temperature in PV-726 are 5 kg / cm2G and 158 oC, upstream pressure and temperature on PV-735 of 2.5 kg / cm2G and 138 oC. For downstream pressure on all valves is 1.03323 kg/cm2G. The obtained mass flow (F) in each valve is 0.514 tons / hr, 0.86 tons / hr and 1,902 tons / hr. The value of the input mass balance of steam in the system is 82.70 tons/hour and the overall output is74.11 tons/hour. Therefore, the total steam loss in  PV-723, PV-726, and PV-735 is around 8.59 tons/hour which mean there are some leak during the process that need to do further investigation

    EKSTRAK DAUN KALIANDRA SEBAGAI INHIBITOR ALAMI LAJU KOROSI ST-37

    Full text link
    The utilization of natural resources as a metal inhibitor is widely researched. The extract of Calliandra leaves is one of the natural resources utilized to prevent the corrosion rate. It contains high tannins, which is a natural compound that can be utilized as an inhibitor of the corrosion rate. The research is aimed to find out the efficiency of Calliandra leaves extract as the natural inhibitor for steel ST-37. The experiment method is applied to vary the extract of Calliandra leaves in the corrosive medium. Meanwhile, the extraction of Calliandra leaves uses the maceration method. The extraction of Calliandra leaves with the solvent uses an evaporation process using a rotary vacuum evaporator. The extract used as the inhibitor is determined in 5%, 10%, and 20% of concentrations. The sample test of corrosion used is steel ST-37 with 4 × 4 cm of dimension and 0.2 cm of thickness. The best inhibition efficiency is 99.73% with an inhibition concentration of 20% in HCl. It shows that the extract of Calliandra leaves works well as an inhibitor, and it is efficient to inhibit the corrosion rate

    PENGARUH FRAKSI VOLUME TERHADAP KEKUATAN TARIK DAN BENDING KOMPOSIT SERAT SERABUT KELAPA BERMATRIKS POLIESTER

    Full text link
    With natural fibers, namely coconut fibers that are easily found in the surrounding environment and literature studies that have been carried out, starting from the alkalization process, volume fraction, fiber length and utilization which will be used for fiberboard, the author wants to make a composite of coconut fiber fibers and do some The tests are tensile test and bending test. The tensile test results show the smallest tensile strength value at 10% fiber volume variation of 14.64 MPa and the largest tensile strength at 30% volume fraction variation with a value of 20.90 MPa. Increase in fiber volume variation 10% to variation The bending test results show the smallest bending strength value at 10% fiber volume variation of 34.81.64 MPa and the largest tensile strength at 30% volume fraction variation with a value of 49.41 MPa. The increase in the volume of the coco fiber fraction which is directly proportional to the tensile and bending strength values ​​is due to the increasing contribution of the fiber to withstand the load

    ANALISIS PERBANDINGAN PRODUKSI BIOGAS CAMPURAN KOTORAN AYAM DAN KOTORAN SAPI DENGAN STARTER RUMEN SAPI

    Full text link
    Biogas is a combustible gas produced by anaerobic activity or the fermentation of organic matter by microorganisms. This study produces biogas made from chicken manure and cow manure with a ratio of mass composition D1 (25%: 75%), mass composition D2 (50%: 50%), and mass composition D3 (75%: 25%) with a combined mixture that is 75% of the digester capacity and the addition of beef rumen by 1 kg in all variations as a starter. The purpose of this study was to examine the effect of composition on pressure, mass, temperature, and flame quality of the biogas production of chicken manure and cow manure with a mixture of cow rumen. Data were collected every 06.00 WITA and 18.00 WITA and temperature measurements were every 6 hours for 20 consecutive days. The results showed that the temperature at 18.00 WITA was better than at 06.00 WITA with the highest temperature occurring in the D2 variation of 29.85oC. The results of the measurement of biogas mass and pressure showed that the highest value was in the D3 variation at 18.00 WITA on the day to -9 with values ​​of 68.32 grams and 0.054 bar, respectively, with the total mass and pressure of biogas in the D3 variation of 401.14 grams and 0.391 bar.   Keywords: Biogas, Chicken Manure, Cow Manure, and Cow Rumen

    COVER

    No full text

    231

    full texts

    257

    metadata records
    Updated in last 30 days.
    ROTOR
    Access Repository Dashboard
    Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇