The common problem occurs in fish mapping using autonomous surface vehicles (ASV) is pitching stability. Some researchers have indicated that problem affects the results of mapping. The target of this system is to des...
The common problem occurs in fish mapping using autonomous surface vehicles (ASV) is pitching stability. Some researchers have indicated that problem affects the results of mapping. The target of this system is to design an Autonomous Pitching System (APS) for ASV using numerical simulation software. The simulation is done by implement APS into the system, producing an oscillatory motion from the ASV. For both dynamics of craft in short and long periods, APS with proportional controller (P), proportional-integral controller (PI), and proportional-integral-derivative controller (PID) are developed in order to minimize the oscillatory behaviour. It was found that for the short period dynamics, the APS with PI controller was the optimal controller, followed by the PID controller and then the P controller. For the long period dynamics, the APS with PID controller was optimal.
Theoretical studies have been conducted on the application of solar air heater for preheating the air of broiler house. The air heating system of broiler house was use a gas air heater and equipped with rocks bed as t...
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The mechanical properties of the material is affected by the microstructure, and the microstructure is determined by the cooling time. This research aims to evaluate the effect of varying quenching media on cooling ti...
The mechanical properties of the material is affected by the microstructure, and the microstructure is determined by the cooling time. This research aims to evaluate the effect of varying quenching media on cooling time and microstructures of leaf spring steel AISI 5160. The leaf spring steel AISI 5160 was heat-treated at 850 oC for 30 minutes and was cooled in the varying quenching media. The quenching media were oil, water, water 1 L + soap 10 g, water 1 L + soap 15 g, water 1 L + soap 25 g, water 1 L + urea 10 g, water 1 L + urea 15 g, water 1 L + urea 25 g sand, air, and furnace. The cooling times were calculated by newton's law of cooling and heating equation, the microstructures were observed by an optical light microscope, and the percentages of martensite and retained austenite in the material were calculated by Optimas software. The results show that the fastest cooling time is 20.20 s cooled in water 1 L + urea 25 gr, and the longest cooling time is 82800 s cooled in the furnace. The microstructures of the material were martensite and retained austenite when the materials are cooled in a water and oil base quenching media. The microstructures were ferrite and pearlite when the materials are cooled in air, sand, and the furnace. The lowest percentage of the martensite is 78.4 % cooled in oil quenching media, and the highest percentage of the martensite is 94.4 % cooled in water + urea 25 g.
The weakness of an outdoor solar water heater (SWH) experiments is the difficulty in determining its thermal behavior. The fluctuation of solar radiation intensity causes the supply of energy received by SWH also fluc...
The weakness of an outdoor solar water heater (SWH) experiments is the difficulty in determining its thermal behavior. The fluctuation of solar radiation intensity causes the supply of energy received by SWH also fluctuate. The result is that the thermal behavior of the SWH cannot be known for specific parameters. This paper aims to investigate the thermal behavior of an active type SWH containing paraffin wax using the constant heat flux method. A phase change material (PCM) inserted into the capsule. The capsules were arranged in a tank to form a heat exchanger (HE). The thermocouples were mounted both on the waterside and the PCM side. The solar simulator installed on the top of the collector, and the SHW system placed indoors. The heat flux and water flow were set at 1000 W/m2 and 2 LPM, respectively. The temperatures of water and PCM for 143 minutes charging recorded. The data obtained were used to analyze the thermal behavior of water and PCM. The results showed that the average heating rate of water and PCM was 0.227 °C/min and 0.205 °C/min, respectively. The value of this adjacent average heating rate shows that HE has functioned well in removing heat energy from water. The accumulated thermal energy produced was 13.08 MJ. Indoor experiments can reveal the thermal behavior of the SWH-PCM systems.
This paper aims to provide an overview of what a Qualitative Comparative Analysis (QCA) method is, its differences with the classical methods, the principles, and the QCA types. Literature studies and Indonesia megapr...
This paper aims to provide an overview of what a Qualitative Comparative Analysis (QCA) method is, its differences with the classical methods, the principles, and the QCA types. Literature studies and Indonesia megaproject case study is used to explain the concept of the QCA method. A comprehensive discussion of this paper produces a concise description of the QCA method that has the potential to be used to study multivariable research with small sample size. This study also succeeded in formulating a framework that can be used as a guide for researchers in determining when to use the QCA method.
This study observed the effect of bed material in the pyrolysis process. Also, other parameter such as the heating rate have been observed. The biomass studied is Sunan Candlenut cake. This biomass is a potential comm...
This study observed the effect of bed material in the pyrolysis process. Also, other parameter such as the heating rate have been observed. The biomass studied is Sunan Candlenut cake. This biomass is a potential commodity as a producer of biodiesel. Through the method of mechanical press and esterification, it will leave waste in the form of a cake that still contains crude oil. Trapped oil can be converted into bio-oil through the pyrolysis technique. Parameters that affect the pyrolysis process include the addition of bed material and heating rate. Pyrolysis of this candlenut cake has been tested to determine the amount of activation energy. Heating rates are varied to 5, 10 and 20 K per minute and bed material used is iron sand. The testing instruments uses Thermogravimetric Analysis (TGA). The results show that the lowest activation energy of 15.497 [KJ/mol] is achieved when added iron sand at the heating rate of 10 K per minute.
This paper presents the development of an add-on for CAD system generating assembly structure automatically based on a given Bill of Materials (BOM). The BOM in Excel format is scanned by the system and the system arr...
This paper presents the development of an add-on for CAD system generating assembly structure automatically based on a given Bill of Materials (BOM). The BOM in Excel format is scanned by the system and the system arrange 3D CAD files into assembly at in CATIA V5 CAD system automatically. This program has been tested and succeeded well at compiling 3D assembly based on 3D part file data that is available or not available. If the 3D file is not available then the 3D assembly is still generated according to the assembly structure listed on Excel file but its 3D representation does not appear.
This research aims to: (1) producing android-based Electronic Fuel Injections (EFI) learning media; (2) knowing the feasibility of android-based EFI learning media; and (3) knowing students' responses to the learn...
This research aims to: (1) producing android-based Electronic Fuel Injections (EFI) learning media; (2) knowing the feasibility of android-based EFI learning media; and (3) knowing students' responses to the learning media of the Android-based Electronic Fuel Injections (EFI) system. The rsearch was conducted using the Borg and Gall model modified by Sugiyono. The technique of data collection is done by questionnaire, while the data analysis technique uses descriptive quantitative methods. The results of the research were obtained: (1) products in the form of Android-based Electronic Fuel Injections (EFI) system learning media; (2) learning media in terms of material included in the very feasible category and in terms of media included in the very feasible category; and (3) students' responses when testing the product, the aspects of use are included in the category very easily and the aspects of usefulness are included in the category of very useful. The response of students when testing the use, the aspects of use included in the category is very easy and the usefulness aspects including the category is very useful.
Aluminum is important material due to high strength/weight ratio. Nickel plating is proposed on luminium for the purpose of improving wear resistance, tribological properties, surface hardness, and decorative appearan...
Aluminum is important material due to high strength/weight ratio. Nickel plating is proposed on luminium for the purpose of improving wear resistance, tribological properties, surface hardness, and decorative appearance. There are number of difficulties when electroplating nickel on luminium is expected. The luminium is amphoteric are soluble in both alkaline and acid. The potential difference between luminium and nickel can affect the deposition reaction due to the diameter and the crystal lattice structure of both different atoms. This study developed nickel electroplating on luminium. Copper and zinc are used as intermediate deposits and final pretreatment coating performed with nickel plating. Interface layers that have been produced are investigated to determine the quality of the nickel layer is obtained.
Missile performance of alternative configurations can be evaluated using a variety of methods. These include analytical estimates, computer simulations, laboratory tests, and flight tests. Analytical techniques are th...
Missile performance of alternative configurations can be evaluated using a variety of methods. These include analytical estimates, computer simulations, laboratory tests, and flight tests. Analytical techniques are the simplest and less costly, it provides estimations of missile performance characteristics, such as maximum speed, operational range and time of flight, but the detailed interactions of subsystems are difficult or impossible to predict accurately. Laboratory testing provides credible information, but more costly, and restricted mainly to subsystem evaluation. The most credible means is flight testing, but it is also the costliest and time consumed. So, there is a gap, between the extremes of low-cost, low-credibility analytical methods and high-cost, high-credibility flight testing methods. The gap is filled by computer simulation. This paper describes a brief and comprehensive methods of six-degree-of-freedom computer simulation of tactical missile that can be implemented by using modern programming languages, such as C#, C/C++, or others.
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