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Carburizing is a method for obtaining a sturdy material surface. This hard surface is used for machine elements that intersect with other materials, so failure due to wear can be avoided. However, this increase in hardness has always been followed by decreased ductility. This condition certainly lowers the fatigue life of the material. For that, it is necessary to compromise between surface hardness and ductility. This study used AISI 1045 steel, which has a surface roughness of 0.4 and 4.7 μm with carburation media used, is a mixture of 80% coconut shell charcoal and 20% Barium carbonate. The sample was given the pack carburization treatment at 850°C and holding time for 3 hours, and then cooled in the open air. The samples were reheated at 850°C, holding time for 17 minutes, and then cooled with airflow at speeds of 10.34, 15.51, and 20.06 m/s for 30 minutes. This research shows that the surface of steel with a roughness of 0.4 μm has excellent performance with the hardness and corrosion level respectively 228.6 HV and 2.3586 mpy at cooling airflow rate of 20.06 m/s while the fatigue life of material occurs at the speed of airflow cooling 10.43 m/s.

This research is a development of previous research, where in the previous research, a design innovation was carried out on an alpha-type stirling engine by making the phase angle to 180o, with the aim of reducing the effect when the cold cylinder is compressed, because the phase angle currently used is (90o) with disadvantages, namely the cold cylinder is perpendicular to the top, so that the compression process against gravity. But in previous studies, the generator pipe was too long, causing a lot of energy or heat loss (heat loss) so that the compression speed was small. So that in the research, innovated and analyzed the pipe insulation of alpha-type stirling engine generators, alpha-type stirling engines, 180o phase angle. The research method used is to use the thermodynamic approach with Schmidt theory and the theory of the ideal cycle stirling engine. while the simulation is done using the Ideal Stirling Cycle Calculator. Results investigated shows that providing insulation on the generator pipes of an alpha-type stirling engine for an alpha-type stirling engine with a 180o phase angle is proven to reduce a lot of energy or heat loss (heat loss) due to too long generator pipes, with a heat loss value ratio of 226.66 W for the pipe. generator that uses insulation whose value is smaller than the value of the heat loss when the generator pipe without using isocation is 1,584.12 W.

Pada bulan Februari 2021 di Cilegon, penyebaran Virus Corona (COVID-19) akibat sentuhan benda di sekitar kita sangat mengkhawatirkan sehingga untuk mengurangi penyebarannya dibutuhkan sebuah sistem yang bekerja secara otomatis tanpa sentuhan tangan. Fokus penelitian ini adalah merancang alat pengunci pintu tanpa sentuh berbasis Arduino yang memanfaatkan sensor ultrasonik, sensor suara, magnetic switch, serta kunci slot dengan metode perancangan Pahl dan Beitz. Sehingga dengan adanya alat ini diharapkan mampu mengurangi penyebaran Virus Corona melalui pengunci pintu. Hasil penelitian didapati sensor ultrasonik dapat bekerja dengan baik mendeteksi jarak, magnetic switch memiliki batas pembacaan sejauh 10mm, serta sensor suara yang memiliki kepresisian rendah. Kesimpulan produk dapat digunakan sebagai sarana pencegahan Virus Corona dengan tidak menyentuh kunci slot, namun memiliki kepresisian yang rendah pada sensor suara menyebabkan dibutuhkan lebih dari 1 tepukan agar sensor dapat mendeteksinya.

Fatigue merupakan salah satu penyebab kerusakan dari suatu poros. Kerusakan fatigue tidak dapat diprediksi, bisa terjadi secara tiba-tiba. Oleh karena itu perlu diteliti lebih lanjut tentang penyebab kegagalan fatigue . Pada penelitian sebelumnya sudah banyak yang melakukan improvement pada material yang biasa digunakan sebagai poros untuk meningkatkan kekuatan fatigue , tetapi masih sedikit penelitian yang membahas pengaruh kondisi permukaan pada poros terhadap kekuatan fatigue . Tujuan dari penelitian ini adalah untuk mengetahui pengaruh rasio geometri alur pasak poros terhadap kegagalan fatigue dengan melihat pada rasio kedalaman berapa material akan cepat patah. Metode yang digunakan adalah metode simulasi dengan software SolidWorks. Simulasi fatigue yang digunakan yaitu tipe rotary bending dengan standar pengujian ASTM E466. Varian rasio alur pasak yaitu 3:1 mm, 3:2 mm, dan 3:3 mm dengan masing-masing diberi beban 40%, 50%, 60%, 70%, dan 80% dari ultimate tensile strength material. Hasil yang didapat pada beban 40% untuk varian 1,2,3 mencapai lebih dari 1.000.000 siklus sampai patah. Pembebanan 50% sama seperti pembebanan 40%. Pembebanan 60% varian 1 masih mencapai 1.000.000 siklus, sedangkan varian 2 mendapat 402.699 siklus, varian 3 mendapatkan 317.727 siklus sampai material patah. Pembebanan 70% varian 1 mendapatkan 641211 siklus, varian 2 mendapatkan 201.348 siklus, varian 3 mendapatkan 166.116 siklus sampai material patah. Pembebanan 80% varian 1 mendapatkan 311.218 siklus, varian 2 mendapatkan 123.921 siklus, varian 3 mendapatkan 102.371 siklus sampai material patah. Dengan posisi patah yang sama pada setiap fillet alur pasak.

Electroplating is the coating metals with thin layers of other metals by electrolysis to improve the surface properties of materials, especially corrosion resistance. Electroplating is widely used in the automotive, electronics, medical, aerospace, gas, and oil industries. This study will discuss the effect of substrate surface roughness of AISI 1045 steel toward surface roughness, hardness, corrosion rate, and bonding strength of the coating. The surface roughness of the substrate is obtained by grinding process using sandpaper with grades 80, 320, and 1000. In this study, the coating material is Chromium. The electroplating parameters used in this research are 5-volt voltage, current 500 Amperes, and the time of 15 minutes. From this research, it is known that the surface roughness of the substrate material has an influence on the quality of the coating. The lower the surface roughness, improve the roughness, hardness, corrosion rate, and bonding strength. Keywords: electroplating, surface roughness, hardness, corrosion rate, bonding strength.

Stress concentrations cause many machine element failures. Failure will occur more rapidly if the machine elements obtain repeated and fluctuating loading. For this reason, the material for machine elements must have better fatigue life. There are various attempts made to increase material life and other mechanical properties. In this study, the research sample used is AISI 4140 steel. The samples obtain hardening followed by cooling and tempering. The hardening temperature is 8500C with a holding time of 17 minutes. The cooling media in this research are dry sand, semi-wet sand, and wet sand. Wet measurements based on volumetric ratios. Semi-wet sand with a ratio of sand and water 4: 1, sandy sand 4: 2. The final process is tempering treatment, with a temperature of 2500C. The material fatigue test refers to the JIS Z 2274 Standard. From this study, the heat treatment given can reduce the fatigue life of the material, even though the hardness increases. The higher the cooling rate, the hardness of the material increases, but the fatigue life is low.

One effort to overcome the use of fossil fuels is to use alternative energy sources, including plastic waste. Stirling engine is an external combustion engine that can utilize heat from various heat sources. In this research, an analysis of the design of the engine elements in the alpha-type Stirling engine design innovation is based on plastic waste, so it is expected to get the best and safest engine element design specifications. Based on the analysis results of calculations based on the Kwurmi method, it has been obtained the specifications of the design results of the engine elements are as follows: shaft design (length = 250 mm, diameter = 15 mm), post design ( length = 20 mm, width = 6 mm, thickness = 6 mm), pulley design (driver diameter = 100 mm, diameter driven = 60 mm), belt design (length = 987 mm, width = 30 mm, thickness = 5 mm), Stirling engine (power = 94.3 to 205.4 watts, engine speed = 300 to 1305 rpm, heat temperature = 623 ° k, cold temperature = 305 ° k, phase angle = 180 °, dimension = 580 mm × 250 mm × 700 mm, thermal efficiency = 0.51).

Banten Province, Indonesia, has abundant natural resources. Waste from processing natural resources has not been utilized maximally. Several types of wood and plants used in this study were sengon (albizia Chinensis), bayur (pterspermum javanicum), mahogany (Swietenia mahogany) and rice husk ash as filler. The reference particleboard characteristics used are Indonesian Standard, SNI 03-2105-2006. The characteristics observed were pore diameter, hardness, impact toughness, flexural strength, and thickness development. The particleboard composition is 50% filler, 15% oil palm empty fruit bunches, 20% polyvinyl acetate adhesive, and 15% epoxy resin. The length of fiber used is 5 mm. This research shows that particleboard with mahogany filler has optimum characteristics, namely pore diameter 2.0288 nm, hardness 43 N/mm2, flexural strength 641.65 N/mm2, toughness 3.54 kJ/m2, and thickness swelling 1.20%.

In AISI 410 steel, the characteristic changes observed in this study were the value of hardness, and microstructure shape. Material samples heated on temperature 9000C and held for 45 minutes, with cooling medium variation used are water, used oil, and SAE 20W-50 oil. In the process, tempering the material sample returns heated on 3000C and held for 15 minutes, then cooled in the room open. The results showed that the microstructure formed in AISI 410 steel after heat treatment is martensite lath, ferrite and austenite. From the results has been obtained, that the quenching process with a variety of cooling media used and followed by the tempering process can affect the shape of the microstructure of AISI 410 steel, changes that occur are increase in the hardness value of the material. The results showed that the sample quenching water had the highest hardness is 378 HV, followed by quenching of SAE 20W-50 oil and used oil with grades of 377 and 362 HV, respectively. The increase in hardness value occurs due to changes in the micro structure that occur due to the heat treatment process. The increase in the value of hardness that occurred in the material was 143.7%.

The energy produced by the Sun is heat energy and light energy. One of the uses of solar thermal energy is the thermoelectric generator (TEG). This research on solar thermoelectric generators uses 2 variations of cooling media, namely water cooling media and soil cooling media with a series series for thermoelectrics, while what will be analyzed is the amount of power from both tests and the ability the solar collector absorbs the sun's radiation heat. The test results and calculations determine the calorific value of solar radiation that is absorbed by the collector. That is 25,265 Watts. As for the results of testing the cooling media, the best results were obtained for the water cooling media with the greatest value at 0.04 Watt.

Gasification is a process of changing thermochemical solid fuel into gas. In simple terms, the gasification process can be said as a chemical reaction at high temperatures between biomass and air. The purpose of this study was to determine the effect of AFR on the performance of the TG30-1 gasification engine and compare it with the same engine performance in previous studies. This study uses blowers which are combined with an inverter to vary the frequency of rotation of the motor. From the three tests, the results of different performance analyses were obtained. In this study, experiments on corn cobs biomass for 45Hz motor frequency (90%) produced the best Fire Power and Specific Power at 23.01 kW and 3.71 kW / kg with AFR values of 1.54. Palm shell biomass with 45Hz motor frequency (90%) yields 18.32 kW and 3.24 kW/kg with an AFR value of 1.23. Wood powder biomass with 45Hz motor frequency (90%) produces 22.53 kW and 3.88 kW / kg with an AFR value of 1.36. Rice husk biomass with a 45Hz motor frequency (90%) yields 29.08 kW and 6.39 kW / kg with an AFR value of 1.15.

Use of NACA 0012 at the Sultan Wind Turbine prototype provide value coefficient power turbine at wind speed 5.5 m / s by 0017 , wind speed 6.1 m / s at 0.015 , wind speed 7.7 m / s at 0.016 , wind speed 6.5 m / s for 0018 and wind speed 6.2 m / s by 0017 . Where the value of the highest efficiency obtained at a speed of 6.5 m / s at 0.018 . This result is not as expected to generate sufficient energy.The next development carried out investigations on some kind of airfoil, from investigations obtained by using Qblade software that NACA 6612 has a value of 1.78 CL at 15 degrees angle of attack is the largest of all the airfoil .In this research, NACA 6612 will be simulated with a variable chord length, angle of attack, and wind speed, of these three variables will be created which will map graphics 3d sliding value of the ratio of the 3 variables, this graph will give recommendations most optimum combination of variables to types are mapped wind speed throughout the year, to produce optimum power.Optimum combination of NACA 6612 with wind speed varied from 2-7 m/s is chord length 30 cm and angle of attack 7 degree.

Designing and manufacturing / prototyping surveillance robot that has self-protection mechanism by using nail gun with VDI (Association of German Engineers) method, aims to design and create a robot that capable to conduct reconnaissance missions and protect themselves as well as immobilize the target object. The prototype robot is able to send data in the form of audio and visual through Wireless system by using Wi-Fi (Wireless Fidelity). The robot is equipped with self-protection system such as nail gun that can move in rotation and elevation, it is such an effective weapon to paralyze the targets objects if necessary. This robot is designed to maneuver on the field that has tilt angle up to 30o. Based on the test results, the robot is able to maneuver with speed 2.88 km/h on duration more than 30 minutes and be able to pass the field angle of 35o. Proximity sensors which are used as indicators of arm robots position works well on the pitch and yaw motion. Security system that is designed to shoot also works well. The most effective control radio frequency used is 2.4 GHz and the data sender system frequency is 5.8 GHz.

Remotely Operated Vehicle (ROV) is a small marine craft used for underwater observation. Hence, the analysis of hydrodynamic characteristics is important. Hydrodynamic characteristics can be obtained by fluid dynamic visualization and simulation of Computational Fluid Dynamic (CFD). In this paper, ROV Hydrodynamic characteristics begin by forming a three-dimensional (3D) ROV model, forming link elements (mesh) from the 3D ROV model, and forming the computational domain used for CFD simulations. CFD simulations were conducted by analyzing the fluid flow angle variations that represent motion of the ROV, namely translational motion and rotational motion towards the vertical axis (yaw). The simulation results obtained were compared with the previous ROV design that had been developed, so as to obtain an evaluation of the results of the design optimization. The results showed an increase in the hydrodynamic characteristics of the optimal ROV design indicated by the value of drag, pressure distribution, and fluid flow contour.

Perkembangan material di dunia industri semakin menuntut untuk rekayasa terhadap material tersebut sehingga dihasilkan material yang kuat dan ulet sesuai dengan kebutuhan. Salah satu metode untuk meningkatkan sifat fisik dari material adalah dengan carburizing atau proses karburisasi. Metode penelitian yang digunakan dalam penelitian ini adalah proses karburisasi yang diikuti dengan perlakuan pendinginan cepat (quenching) untuk meningkatkan kekerasannya sehingga permukaan logam menjadi lebih tahan aus, kemudian menambahkan energizer atau bahan pengaktif kalsium karbonat dan batu bara sub bituminous yang akan mempercepat terbentuknya gas CO rendah. Penelitian ini bertujuan mencari solusi perlakuan panas yang baik pada baja AISI 3115 maka dilakukan perlakuan panas (heat treatment) pada variasi suhu 750°C, 850°C, 950°C. Disusul dengan pendinginan cepat menggunakan cairan berupa air dalam suatu wadah, yang diharapkan dapat meningkatkan kekerasan baja AISI 3115. Hasil penelitian adalah proses karburasi yang diikuti proses perlakuan panas dan pendinginan cepat, serta penambahan bahan pengaktif kalsium karbonat dan batubara sub bituminous mempunyai pengaruh untuk meningkatkan tingkat kekerasan pada baja karbon rendah AISI 3115. Semakin tinggi temperatur pada proses heat treatment maka kekerasan semakin meningkat dan nilai tingkat karbon juga ikut meningkat berdasarkan parameter suhu yang tinggi, dikarenakan peningkatan nilai karbon pada baja menggunakan karbon berupa batubara subituminus dengan pengikat berupa calsium karbonat. Fungsi dari calsium karbonat juga sebagai media untuk mempercepat proses karburasi. Pengaruh temperatur terbaik terdapat pada suhu 950°C. Pada penelitian ini didapatkan nilai kekerasan tertinggi sebesar 38,14. dan memiliki laju korosi terlambat dengan nilai 2,86 mpy dan foto struktur mikro terbaik terdapat pada suhu 850°C dikarenakan ferrit yang bewarna terang pada baja menandakan bahwa baja bersifat tidak keras, sedangkan pearlit yang bewarna gelap bersifat keras karena titik hitam lebih banyak dibandingkan titik putih maka nilai kekerasan terbaik di dapat pada suhu 850°C.

Companies in various fields of industry are competing to produce optimum products quality, including oil and gas industry. Consumer's demand for product quality also varies depend on the consumer's plant reqirements. Explored natural gas will be fractionated to serve a wide range of refined gas products. Distillation column is the most commonly used unit operation to separate in oil and gas industry. Depropanizer column is one of the distillation column that produces distilate product that rich in propane. In this study, the optimization is performed and focused to optimize the quality product of depropanizer column. Depropanizer column system is modelled based on the plant design data in HYSYS and FOPDT to simulate and determine the plant gains. The plant gains are utilized to predict the optimized the reflux mass flow and reboiler heat rate by using ES algorithm. The optimizaton results will be reperent as set point of mass flow reflux and reboiler heat rate. In this study, in order to obtain 0.9552 and 0.055 propane fraction in top product and bottom product, the set point of reflux mass flow and reboiler heat rate have to be 25782,17 kg/h and 1097572514 kJ/h.

This paper proposes an optimization algorithm based on human fight and learn from each duelist. The proposed algorithm starts with an initial set of duelists. The duel is to determine the winner and loser. The loser learns from the winner, while the winner try their new skill or technique that may improve their fighting capabilities. A few duelists with highest fighting capabilities are called as champion. The champion train a new duelist such as their capabilities. The new duelist will join the tournament as a representative of each champion. All duelist are re-evaluated, and the duelists with worst fighting capabilities is eliminated to maintain the amount of duelists. Several benchmark functions is used in this work. The results shows that Duelist Algorithm outperform other algorithms in several functions.

In this paper, the active suspension system is designed to reduce vibration on the passenger seat caused by change in road-surface shapes or disturbance. PID control is utilized in the design of this active suspension system, and Direct Synthesis method is proposed to tune PID parameters. Direct Synthesis method optimize PID tuning parameters to achieve desired output response in different road surface. In this study, three interference signals are used as disturbance from surface road i.e step, impulse, and sinus. The aim of the suspension control design is to obtain the control parameters that conform to ISO 2631. The simulation results show that value of τc 0.0002 for step disturbance provide aRMS 0.086 m/s2 and damping ratio 0.21. For impulse input the value of τc 0.002 provide aRMS 0.112 m/s2 and damping ratio of 0.22. For sinus input value of τc 0.00005 provide aRMS 0.09 m/s2.

Di zaman yang semakin modern ini banyak kebutuhan yang semakin meningkat, salah satunya adalah energi. Energi fosil yang digunakan pada mesin-mesin sebagai bahan bakar utama telah banyak digunakan. Pemanfaatan energi yang dilakukan secara berlebihan semakin menurunkan ketersediaan energi fosil tersebut. Untuk mengurangi ketergantungan pada energi fosil yang pembentukannya sangat lama dan cepat habis, maka dari itu dibutuhkan adanya pemanfaatan energi alternatifyang lebih ramah lingkungan dan mudah didapat.Penggunaan sepeda sebagai moda transportasi yang mudah dan bermanfaat menjadi salah satu pilihan. Memanfaatkan putaran roda untuk memutar alternerator yang nantinya akan menghasilkan listrik, kemudian energi listrik tersebut disimpan pada akumulator. Pada saat akan digunakan maka energi listrik pada akumulator disalurkan pada mesin saat berfungsi sebagai motor listrik untuk memutar roda belakang. Proses dalam menghasilkan energi listrik ini yang dimanfaatkan sebagai energi terbarukan pada penggunaan sepeda. Selain memanfaatkan putaran pada roda belakang yang disambungkan pada alternerator, bisa juga dengan memanfaatkan fly wheel yang disambungkan dengan transmisi rantai pada sepeda. Fly wheel tersebut dimanfaatkan putarannya pada saat sepeda berhenti atau melakukan pengereman. Beban berat pada fly wheel membuatnya bisa berputar terus dan membutukan waktu yang cukup lama untuk berhenti walaupun sumber tenaga pemutar telah berhenti. Hal ini yang dimanfaatkan dalamKinetic Energy Recovery System (KERS) pada mobil formula one dan diaplikasikan pada pengereman sepeda sebagai penghasil energi untuk memutar alternerator, agar pengisian akumulatortetap bisa dilakukan pada saat mengerem dan berhenti dari kecepatan tinggi. Dari hasil perhitungan, Dengan daya 1801 W pada kecepatan 25 km/jam energi kinetik flywheel sebesar 101,2 joule dan dapat menghasilkan arus listrik sebesar 0,78 amper pada putaran alternator 1661,83 rpm. Dengan menggunakan panjang rantai 1,49 meter pada roda belakang menuju flywheel dan 0,67 meter pada flywheel menuju alternator