Mechanical Engineering Commons^™

Characteristics Of Vacuum Freeze Drying With Utilization Of Internal Cooling And Condenser Waste Heat For Sublimation, Muhammad Idrus Alhamid, Nasruddin Yusuf, Indra Teuku Meurah Mahlia, Engkos Ahmad Kosasih, Muhamad Yulianto, Rio Ricardi

Makara Journal of Technology

Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing …

A New Experimental Approach To Evaluate Plasma-Induced Damage In Microcantilever, Yuki Nishimori, Shinji Ueki, Masakazu Sugiyama, Seiji Samukawa, Gen Hashiguchi

Makara Journal of Technology

Plasma etching, during micro-fabrication processing is indispensable for fabricating MEMS structures. During the plasma processes, two major matters, charged ions and vacuum–ultraviolet (VUV) irradiation damage, take charge of reliability degradation. The charged ions induce unwanted sidewall etching, generally called as “notching”, which causes degradation in brittle strength. Furthermore, the VUV irradiation gives rise to crystal defects on the etching surface. To overcome the problem, neutral beam etching (NBE), which use neutral particles without the VUV irradiation, has been developed. In order to evaluate the effect of the NBE quantitatively, we measured the resonance property of a micro-cantilever before and after …

Fatigue Life Prediction Of The Keel Structure Of A Tsunami Buoy Using Spectral Fatigue Analysis Method, Angga Yustiawan, Ketut Suastika, Wibowo Harso Nugroho

Makara Journal of Technology

One of the components of the Indonesia Tsunami Early Warning System (InaTEWS) is a surface buoy. The surface buoy is exposed to dynamic and random loadings while operating at sea, particularly due to waves. Because of the cyclic nature of the wave load, this may result in a fatigue damage of the keel structure, which connects the mooring line with the buoy hull. The operating location of the buoy is off the Java South Coast at the coordinate (10.3998 S, 108.3417 E). To determine the stress transfer function, model tests were performed, measuring the buoy motions and the stress at …

The Plasma Electrolysis Phenomenon In A Two-Compartment Reactor For Chlor-Alkali Production, Nelson Saksono, Fakhrian Abqari, Setijo Bismo

Makara Journal of Technology

Chlor-alkali is one of the most important processes in the chemical industry. It produces chlorine and caustic soda, which become the main feedstock of daily products. The aim of this study is to report the phenomenon of plasma electrolysis and how it can be used in chlor-alkali production for more efficient energy consumption. When the plasma is formed, the current fluctuates and gradually declines. Plasma electrolysis begins with the process of electrolysis itself. Due to Joule heating, gas bubbles are formed and a sheath is made on both electrodes, resulting in the plasma field. Plasma electrolysis can be identified by …

Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction, Arief Udhiarto, Sri Purwiyanti, Daniel Moraru, Takeshi Mizuno, Michiharu Tabe

Makara Journal of Technology

We study nanowire silicon pin and pn-junctions at room and low temperature. Photovoltaic effects are observed for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered to have the main role for single-photon detection capability. Fundamental mechanism of dopant-based single-photon detection in nanowire pn-junction is described in details.

Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell, Mohd Khairul Bin Ahmad, Kenji Murakami

Makara Journal of Technology

Aligned Rutile TiO2 nanorods (r-TNRs) and TiO2 nanoflowers (r-TNFs) were successfully prepared by hydrothermal method. Using hydrochloric acid (HCl) as chelating agent and titanium butoxide (TBOT) as precursor, aligned r-TNRs with r-TNFs were successfully growth onto fluorine-doped tin oxide (FTO) with different morphologies. The influences of surface morphologies to the rutile based Dye-sensitized solar cell (DSC) efficiency are discussed. The highest lightto- electric energy conversion efficiency, 1.80% is achieved using different concentration under simulated solar light illumination of 100 mWcm-2 (1.5 AM).

Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method, Rangga Winantyo, Devinda Liyanage, Kenji Murakami

Makara Journal of Technology

This paper reports the effect of TiCl4 on the performance of ZnO based DSC. ZnO was used due to its stability against photo-corrosion and photochemical properties similar to TiO2. Thin films of nanocrystalline ZnO were deposited on transparent conducting oxide glass using spray method. The ZnO films were treated using TiCl4. The cell’s efficiency was found to be 2.5% with TiCl4 post-treatment and 1.9% without TiCl4 post-treatment.

Determining The Air Gap Length Of An Axial Flux Wound Rotor Synchronous Generator, Abdul Multi, Iwa Garniwa, Uno Bintang Sudibyo

Makara Journal of Technology

The air gap length of the designed axial flux wound rotor (AFWR) synchronous generator is determined properly according to the design parameters. One of the distinct advantages of an axial flux (AF) machine is its adjustable air gap. An AF generator’s performance might be controlled by adjusting its air gap. The designed generator has a smallscale capacity that has 1 kW, 380 V, and 50 Hz. The windings are laid into slots made from laminated core. The slots are carved in the face of the stator and rotors. The generator has a single-double-sided slotted wound stator sandwiched between twin rotors. …

Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis, Suprapto Soemardan, Widodo Wahyu Purwanto, Arsegianto Arsegianto

Makara Journal of Technology

Gas production rate is one of the most important variables affecting the feasibility plan of gas field development. It take into account reservoir characteristics, gas reserves, number of wells, production facilities, government take and market conditions. In this research, a mathematical model of gas production optimization has been developed using marginal cost analysis in determining the optimum gas production rate for economic profit, by employing the case study of Matindok Field. The results show that the optimum gas production rate is mainly affected by gas price duration and time of gas delivery. When the price of gas increases, the optimum …

Heating Effects Through Harmonic Distortion On Electric Cables In The Built Environment, Kevin O'Connell

Doctoral

Under ideal circumstances, electric power supply voltage and current waveforms should be sinusoidal. However, this is very seldom the case in the built environment, due to the proliferation of non-linear loads. Examples of non-linear loads are those containing switched mode power supplies, reactors and electronic rectifiers/inverters. Common devices such as personal computers, fluorescent lighting, electric motors, variable speed drives, transformers and reactors and virtually all other electronic equipment are examples of non-linear loads. Non-linear loads are the norm in the built environment rather than the exception. Such loads produce complex current and voltage waves and simple spectral analysis of these …

Formula Electric : Powertrain, Mark Allison, Bryan Bidwell, Stuart Hopson, Jackson Smith, Carlos Streegan, Dominic Villa

Interdisciplinary Design Senior Theses

The Santa Clara Formula Electric team designed, and manufactured a powertrain for an electric racecar according to the rules prescribed by the SAE International Formula Electric competition. The powertrain is divided into subsystems: the battery pack, battery pack cooling system, motor controller, and the motor. The battery pack was constructed, but full electrical connection of all cells were not made. The pack was not integrated with the motor and motor controller. In addition, due to time constraints, extensive testing could not be completed.

Lunalight - Bringing Light To The Expanding World, Gabriela M. Igel, Daniel J. Patrick, Kimberley M. Smith

Materials Engineering

The LunaLight, a solar rechargeable light and cell phone charger, addresses the lack of access to electricity faced by 1.4 billion of the world’s population (International Finance Corporation). The LunaTech team has developed a product that is bright, simple, compact, versatile and competitive with existing products. Through a partnership with the non-profit organization One Million Lights, LunaTech has improved a previous team’s design to address user feedback, concerns of durability, and manufacturability.

The LunaLight design includes a 5 component plastic housing held together by 4 screws, a surface mounted PCB, a lithium-ion (Li-Ion) battery, one high-brightness LED, a solar panel, …

An Efficient Navigation-Control System For Small Unmanned Aircraft, Jonathan Alejandro Girwar-Nath

Electronic Theses and Dissertations

Unmanned Aerial Vehicles have been research in the past decade for a broad range of tasks and application domains such as search and rescue, reconnaissance, traffic control, pipe line inspections, surveillance, border patrol, and communication bridging.

This work describes the design and implementation of a lightweight Commercial-Off-The-Shelf (COTS) semi-autonomous Fixed-Wing Unmanned Aerial Vehicle (UAV). Presented here is a methodology for System Identification utilizing the Box-Jenkins model estimator on recorded flight data to characterize the system and develop a mathematical model of the aircraft. Additionally, a novel microprocessor, the XMOS, is utilized to navigate and maneuver the aircraft utilizing a PD …

Structural Health Monitoring Data Transmission For Composite Hydrokinetic Turbine Blades, A. Heckman, Joshua L. Rovey, K. Chandrashekhara, Steve Eugene Watkins, Daniel S. Stutts, Arindam Banerjee, Rajiv S. Mishra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Rapid Tool Heating, Jason Chi, Bobby Dodge

Mechanical Engineering

Quatro Composites creates various molded parts for an array of industries. They are seeking to improve their thermoplastic molding process by decreasing the amount of time to heat up the steel tool that molds the thermoplastics. Currently, it takes approximately 1 hour to heat up their 120 pound steel mold from room temperature to approximately 700°F. The goal of this project is to create an optimum heating method that will minimize that heating time to about 20 minutes or less. It is critical for the stakeholders (Quatro Composites) to have a faster heating time in order to increase their production …

Design Of An Energy Efficient Virtual End Node Client Using Openadr2.0a And Smap, Kevin Navero

BioResource and Agricultural Engineering

Demand Response (DR) describes the set of actions taken to impose a reduction in electrical loads to stabilize the power grid and decrease costs. It is used when power grid emergencies or extremely high demand and congestion, threaten the electricity supply-demand balance. Automated Demand Response (ADR) describes a web-based control system that triggers DR events automatically by signaling other pre-programmed control systems. This project intends to use the OpenADR2.0 specifications provided by the OpenADR Alliance to construct an open source Virtual End Node (VEN) client to retrieve DR signals. The Simple Measurement and Actuation Profile (sMAP) software is also used …

Low Speed Alternator Design, Scott Merrick

Electrical Engineering

No abstract provided.

Micro Hydropower System, Christpher Neally, Ian Verstuyft

Electrical Engineering

The micro hydropower project strives to meet the needs of a specific village in northern Thailand in partnership with Engineers Without Borders. Specifically, the electrical side of the system must be designed to convert the mechanical power of a flowing river that is turning a turbine into sustainable and dependable power. Currently available hydropower systems will be considered, analyzed, and tailored to suit the specific needs of the community in need. The system to be designed will be flexible enough to demonstrate proof-of-concept with the limited maximum generable power in lab while having the ability to be easily scaled for …

Cal Poly Brocade Challenge 2013, Chandler Morehardt, Alexa Coburn, Juan Silva, Kerry Sun, Greg Wang, Raul Chagoya, Jd Torres

Architectural Engineering

No abstract provided.

Wind And Hydroelectric Power Simulation For The Dc House Project, Randy Lormand, Christopher Goloskie

Electrical Engineering

This project details the design and integration of a wind and hydroelectric power simulation system in correlation with the DC House Project. The simulator uses variable speed drives to rotate a DC motor which then drives a generator to produce output. This output is then regulated using a DC to DC converter which holds the voltage level constant making it easier to interface with other power sources for the house. The test results indicate that the simulator will be able to produce two separate power outputs that will provide at least 70 Watts of power in the acceptable speed range …

Swing Human Powered Generator: For The Dc House Project, Juan Vicente Avelar, Juan Jose Galindo, Juan Pramyr Ramos

Electrical Engineering

The Play Park Human Powered Generator project addresses various ways of generating power. More specifically, this project entails the design and construction of the Swing Power Generator to provide electrical power from mechanical energy. The swing generator will eventually be used as part of the human-powered generators utilized in the DC House project.

A swing generator prototype was built for this project, which demonstrates the feasibility of its use for electrical power source. Detailed design and construction of the swing generator is presented in this report along with results from hardware testing.

Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.

Master's Theses

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …

Micro Modeling Study Of Cathode/Electrolyte Interfacial Stresses For Solid Oxide Fuel Cells, Xinfang Jin, Xingjian Xue

Faculty Publications

Delamination of the cathode/electrolyte interface is an important degradation phenomenon in solid oxide fuel cells (SOFCs). While the thermal stress has been widely recognized as one of the major reasons for such delamination failures, the role of chemical stress does not receive too much attention. In this paper, a micro-model is developed to study the cathode/electrolyte interfacial stresses, coupling oxygen ion transport process with structural mechanics. Results indicate that the distributions of chemical stress are very complicated at the cathode/electrolyte interface and show different patterns from those of thermal stress. The maximum principal stresses take place at the cathode/electrolyte interface …

College Of Engineering Senior Design Competition Spring 2013, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Senior Design Experience

Part of every UNLV engineering student's academic experience, the Senior Design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. Working in teams, the senior design project encourages students to use everything learned in the engineering and computer design programs to create a practical, real world solution to an engineering challenge.

Beyond the classroom ...

Because of the requirement to work in teams, students also build good communication skills, presentation skills and even business writing skills. They also have to …

Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type …

Design And Testing Of Novel Mouthguard With Intermediate Nitinol And Foam Layers, Adam Kessler

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is the aim of this study to investigate a novel mouthguard design that incorporates the use of a nickel-titanium (Nitinol) layer and thin foam layer in addition to EVA layers. It is thought that the Nitinol layer can distribute the force of an impact and that the thin foam layer may absorb this distributed force better than a solid EVA mouthguard of the same thickness. Rectangular, flat coupons representative of several mouthguard configurations were constructed for testing using an instrumented drop-weight impact tower. The coupon configurations include a control made of laminated EVA, a group of laminated EVA and …

Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor, Lorin E. Stevens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to the current public demand of faster, more powerful, and more reliable electronic devices, research is prolific these days in the area of high electron mobility transistor (HEMT) devices. This is because of their usefulness in RF (radio frequency) and microwave power amplifier applications including microwave vacuum tubes, cellular and personal communications services, and widespread broadband access. Although electrical transistor research has been ongoing since its inception in 1947, the transistor itself continues to evolve and improve much in part because of the many driven researchers and scientists throughout the world who are pushing the limits of what modern …

Analysis Of An Improved Imu-Based Observer For Multirotor Helicopters, John Charles Macdonald, Robert C. Leishman, Randal W. Beard, Timothy W. Mclain

Faculty Publications

Multirotor helicopters are increasingly popular platforms in the robotics community. Making them fully autonomous requires accurate state estimation. We review an improved dynamic model for multirotor helicopters and analyze the observability properties of an estimator based on this model. The model allows better use of IMU data to facilitate accurate state estimates even when updates from a sensor measuring position become less frequent and less accurate. We demonstrate that the position update rate can be cut in half versus typical approaches while maintaining the same accuracy. We also find that velocity estimates are at least twice as accurate no matter …

Biodiesel Reactor Design With Glycerol Separation To Increase Biodiesel Production Yield, Budy Rahmat, Imas Siti Setiasih, Roni Kastaman

Makara Journal of Technology

The study consisted of reactor design used for transesterification process, effect of glycerol separation on transesterification reaction, determination of biodiesel quality, and mass balance analysis. The reactor was designed by integrating circulated pump/stirrer, static mixer, and sprayer that intensify the reaction in the outer tank reactor. The objective was to reduce the use of methanol in excess and to shorten the processing time. The results showed that the reactor that applied the glycerol separation was able to compensate for the decreased use of the reactant methanol from 6:1 to 5:1 molar ratio, and changed the mass balance in the product, …

Development Of Seebeck-Coefficient Measurement Systems Using Kelvin-Probe Force Microscopy, Kazutoshi Miwa, Faiz Salleh, Hiroya Ikeda

Makara Journal of Technology

Thermoelectric device is investigated by a number of researchers in order to enhance the thermoelectric efficiency. It is known that the efficiency can be improved by quantum effect. However, it is difficult to measure the thermoelectric characteristics of nanometer-scale structures. Thus a new measurement method is expected to be developed. We propose to apply Kelvin-probe force microscopy (KFM) to characterization of thermoelectric materials. KFM can locally observe surface potential of Fermi energy of a sample without touching the sample surface. In the present paper, we estimate the Seebeck coefficient of thin Si-on-insulator layers using KFM.