Mechanical Engineering Commons^™

Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo

Makara Journal of Technology

The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than …

The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan

Makara Journal of Technology

The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and …

Nd–Fe–B Nanoparticles Through Surfactant Assisted Mechanical Milling And Alloy Design, Jordann M. Bornhoft

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Surfactant-assisted mechanical milling has been used to produce discrete nanoparticles of both Nd-Fe-B and Sm-Co amenable for bottom-up production of nanostructured or nanocomposite permanent magnets. However, in Nd-Fe-B the comminution of the material proceeds by transgranular fracture, which influences both the morphology of the nanoparticles and the magnetic properties. This paper utilizes alloy design to alter the fracture behavior from transgranular fracture to intergranular fracture. Nd-rich Nd₂Fe₁₄B alloys were produced by melt spinning in an overquenched state. The melt spun ribbons were annealed at 700°C and 800°C to ensure complete crystallization and to form different grain …

Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto

Makara Journal of Technology

The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by …

Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan

Makara Journal of Technology

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …

Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut

Makara Journal of Technology

Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look …

Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura

Makara Journal of Technology

The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a …

Fabrication And In Vivo Thrombogenecity Testing Of Nitric Oxide Generating Artificial Lungs, Kagya Amoako, Patrick Montoya, Terry C. Major, Ahmed B. Suhaib, Hitesh Handa, David O. Brant, Mark E. Meyerhoff, Robert H. Bartlett, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

Hollow fiber artificial lungs are increasingly being used for long-term applications. However, clot formation limits their use to 1–2 weeks. This study investigated the effect of nitric oxide generating (NOgen) hollow fibers on artificial lung thrombogenicity. Silicone hollow fibers were fabricated to incorporate 50 nm copper particles as a catalyst for NO generation from the blood. Fibers with and without (control) these particles were incorporated into artificial lungs with a 0.1 m2 surface area and inserted in circuits coated tip-to-tip with the NOgen material. Circuits (N = 5/each) were attached to rabbits in a pumpless, arterio-venous configuration and run for …

S1nn Gmbh & Co. Kg (Automobile Connectivity Module 1.1), Tyler Alexander Ball

Industrial and Manufacturing Engineering

The results of this report show how when diagnostics were run on the Connectivity Module 1.1, the problems discovered such as potential short-circuiting, 90-degree copper tracing angles, and components overheating/tombstoning were addressed. By using the method of “DMAIC,” which stands for Design, Measure, Analyze, Implement, Control, successful corrections were made. In the first design of the Printed Circuit Board (PCB), 1454 critical issues were found. With the newly designed PCB’s modifications being implemented, only 12 critical issues remained, which were later addressed and corrected. The results from this report are a functional Automobile Connectivity Module 1.1.

Project Management Of High School Shadow And Building An Engineer Day, Andrea M. Carroll

Industrial and Manufacturing Engineering

Building an Engineer Day and High School Shadow are semi-annual outreach events hosted by Cal Poly’s Society of Women Engineers section during fall and spring quarters. The events focus on encouraging women and minorities to take an interest in engineering. These events are the two largest outreach events hosted by The Society of Women Engineers and need to run smoothly in order to provide student attendees with a meaningful experience.

Building an Engineer Day and High School Shadow are currently un-organized and un-planned, which leads to problems with officer retention, increase in expediting process and a low attendance rate at …

Equipment Maintenance And Replacement Decision Making Processes, Michael W. Gage

Industrial and Manufacturing Engineering

This project contains recommendations for the decision making processes for support and production equipment maintenance and replacement for a large defense contractor. Recent literature has been reviewed to provide perspective on current trends in the field. A complete evaluation of their current processes and systems is included with recommendations on areas for improvement. A decision support system is also proposed to supplement their existing decision making.

Fixture For Carbon Fiber Spar Of Human Powered Helicopter, David John Ikeda, Luis Gonzalez

Industrial and Manufacturing Engineering

The following report describes our contribution to Cal Poly Human Powered Helicopter for the 2012 competition for the Sikorsky Prize offered by the American Helicopter Society. In order to win this prize the team needs to build and fly a human powered helicopter for more than 60 seconds reaching and altitude of 3 meters while staying in a 10 meter square box. Our team was created to support the integration of Carbon Fiber parts, specifically the carbon fiber spars with rotor and landing gears. Precise cutting and accurate drilling was needed and our team was tasked with creating a fixture …

Ole Miss Engineer 2013-2014

Ole Miss Engineer

No abstract provided.

Loading Path Determination For Tube Hydroforming Process Of Automotive Component Using Apdl, E. Masoumi Khalil Abad, Amir Ghazanfari, R. Hashemi

Faculty Publications, Mechanical Engineering

In this study, an extended stress-based forming limit diagram (FLD) for prediction of necking based on the Marciniak and Kucznski (M-K) model is represented and applied in tube hydroforming. The bulge forming of a straight tube is simulated by finite element method and verified with published experimental data. This adaptive simulation technique is based on the ability to detect the onset and growth of defects (e.g., bursting and wrinkling) and to promptly readjust the loading paths. Thus, a suitable load path is determined by applying Adaptive Simulation Method in ANSYS Parametric Design Language (APDL).

Crack Growth Behavior Under Creep-Fatigue Conditions Using Compact And Double Edge Notch Tension-Compression Specimens, Santosh B. Narasimha Chary

Graduate Theses and Dissertations

The American Society for Testing and Materials (ASTM) has recently developed a new standard for creep-fatigue crack growth testing, E 2760-10, that supports testing compact specimens, C(T), under load controlled conditions. C(T) specimens are commonly used for fatigue and creep-fatigue crack growth testing under constant-load-amplitude conditions. The use of these specimens is limited to positive load ratios. They are also limited in the amount of crack growth data that can be developed at high stress intensity values due to accumulation of plastic and/or creep strains leading to ratcheting in the specimen. Testing under displacement control can potentially address these shortcomings …

Design And Construction Of An Omni-Directional Soccer Ball Thrower, Andrew James Marquette

Undergraduate Honors Capstone Projects

Introduction

We are ODST the Omni-Directional Soccer Ball Thrower team which designed the soccer ball launching machine. Working in direct correlation with the project sponsor John Meade from Athlonic Sports this is the report outlining the soccer ball thrower. John from Athlonic Sports came up with the overall project and initial project vision. There are soccer ball launching machines on the market but lacking mobility, not amiable and are heavy. The design needed to be mobile, amiable, lightweight, and have a soccer ball capacity incorporated into the machine. This will allow coaches to repeatability place the soccer ball in certain …

Physics Trick - Balanced Can, Said Shakerin

All Faculty Articles - School of Engineering and Computer Science

The ordinary 12-oz beverage cans in the figures below are not held up with any props or glue. The bottom of such cans is stepped at its circumference for better stacking. When this kind of can is tilted, as shown in Fig. 1, the outside corners of the step touch the surface beneath, providing an effective contact about 1 cm wide. Because the contact is relatively wide and the geometry is symmetrical, it is easy to balance an empty can by simply adding an appropriate amount of water so that the overall center of mass is located directly above the …

The Effects Of Wrist Orthoses On The Stiffness Of Wrist Rotations, Daniel Brad Seegmiller

Theses and Dissertations

Wrist orthoses are the most common upper limb orthoses, being used by thousands of individuals each year to stabilize, immobilize, or support the wrist joint. Wrist orthoses achieve their function by altering the stiffness of the wrist joint (Figure 1-1). However, there is no quantitative understanding of how wrist orthoses affect wrist stiffness, and consequently, wrist orthosis development often relies on feel, intuition, or empirical heuristics rather than a methodical, quantitative approach. Because wrist movement control is dominated by wrist joint stiffness (Charles and Hogan 2011) a quantitative understanding of how wrist orthoses alter the stiffness of the wrist is …

Subway Rail Car Filter Sampling Tool, Brian Hong, Julia Pollard, Philip Ybarra

Mechanical Engineering

The following design report has been prepared by Team Slice for both Cal Poly’s Mechanical Engineering Department and Lawrence Livermore National Laboratory. This report provides an overview of the design ideation process of creating a subway rail car filter sampling tool. This cutting tool will take samples of HVAC filters from subway railcars in New York City, NY. These samples will then be used for processing in biological terror emergency response situations. This device will provide an easy, safe, and user friendly tool to cut filter samples. The current method of cutting is a pair of scissors or shears, which …

Computer Controlled Vegetable Oil Fuel System, Joseph W. Souza

Mechanical Engineering

No abstract provided.

Development And Validation Of A Human Knee Joint Finite Element Model For Tissue Stress And Strain Predictions During Exercise, Spencer D. Wangerin

Master's Theses

Osteoarthritis (OA) is a degenerative condition of cartilage and is the leading cost of disability in the United States. Motion analysis experiments in combination with knee-joint finite element (FE) analysis may be used to identify exercises that maintain knee-joint osteochondral (OC) loading at safe levels for patients at high-risk for knee OA, individuals with modest OC defects, or patients rehabilitating after surgical interventions. Therefore, a detailed total knee-joint FE model was developed by modifying open-source knee-joint geometries in order to predict OC tissue stress and strain during the stance phase of gait. The model was partially validated for predicting the …

Cae Methods On Vibration-Based Health Monitoring Of Power Transmission Systems, Brian Fang

Master's Theses

This thesis focuses on different methods to analyze power transmission systems with computer software to aid in detection of faulty or damaged systems. It is split into three sections. The first section involves utilizing finite element software to analyze gear stiffness and stresses. A quasi-static and dynamic analysis are done on two sets of fixed axis spur gears and a planetary gear system using ABAQUS to analyze the stress, strain and gear mesh stiffness variation. In the second section, the vibrational patterns produced by a simple bevel gear system are investigated by an experiment and by dynamic modeling in ADAMS. …

Active Learning Using Model-Eliciting Activities And Inquiry-Based Learning Activities In Dynamics, Jeffrey Phillip Georgette

Master's Theses

This thesis focuses on a year-long project of implementing active learning in undergraduate dynamics courses at Cal Poly San Luis Obispo from 2012-2013. The purpose is to increase conceptual understanding of critical dynamics concepts and to repair misconceptions of the students. Conceptual understanding in Dynamics is vital to understanding the big picture, building upon previous knowledge, and better understanding the behavior of engineering systems. Through various hands-on activities, students make predictions, test their conceptions, and solve real world problems. These active learning methods allow students to improve their learning of Dynamics concepts. Education research on active learning is present in …

Low-Cost Scheffler Solar Concentrator For The Developing World, Darren Sholes, Jason Morgan, Nicholas Fuller

Mechanical Engineering

This report will outline an approach to design, test, and build a low-cost Scheffler solar concentrator to be used for safer, sustainable and cost effective cooking in the developing world. The function of Scheffler concentrators and a proposed method to create one in an economic, environmentally conscious manner is summarized. If successful, the design will be presented in a way that is readily and freely available to anyone in the world. The authors have examined existing technology and researched the availability and cost of different materials. Analysis was performed in order to verify the feasibility of the different design ideas …

The Collapsible Trailer: Design And Manufacture, Robert Hobson

Biomedical Engineering

No abstract provided.

Ultrasonic Propagation And Scattering In Pearlitic Steel, Hualong Du

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Diffuse ultrasonic backscatter measurements have been especially useful for extracting microstructural information and for improving flaw detection in materials. In this dissertation, this approach is applied to inspection of railroad wheels. To improve the wear resistance, the tread surfaces of railroad wheels are usually quenched with water to increase the hardness. The pearlite phase of iron, characterized by alternating ferrite and cementite phases, is created by the quenching and the lamellar spacing within grains increases progressively from the quenched tread surface to deeper locations due to the non-uniform cooling rate. The quench depth is an important parameter governing the wheel …

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles …

Structural And Magnetic Characterization Study Of Hfco7 Alloy With Substitutions Of Si, Ti, Fe, Mn And B, Jacob A. Lewis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Magnetic materials are a critical component of the modern technological society. The market of high-energy product hard magnets is dominated by the rare-earth element containing neodymium-iron-boron (NdFeB) magnets. As a result of worldwide demand coupled with trade restrictions on rare-earth minerals, new magnet compositions are explored to reduce pressure on the already strained market. The hafnium-cobalt alloy system has shown promise as a candidate for filling the gap in saturation magnetization between rare-earth containing alloys and those made with abundant elements. This study explores the magnetic effects of silicon, titanium, iron, manganese and boron substitutions in the hafnium-cobalt-7 (1:7 atomic …

Experimental Study On The Effect Of Air Flow On Soap Bubble Formation, John M. Davidson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Soap bubbles are a common interfacial fluid dynamics phenomenon having applications such as buoyant hollow spherical fillers and flow visualization of large scale airflows. In contrast to the dynamics of liquid drops in gas and gas bubbles in liquid, the dynamics of soap bubbles has not been well documented, possibly because soap bubbles have gas-liquid-gas interfaces. Having the thin-liquid-film interface seems to alter the characteristics of the bubble/drop creation process. Thus, the main objective of this study is to experimentally examine how airflow develops and interacts with the soap liquid film as the film stretches and finally collapses to pinch-off. …

Phonon Transport Analysis Of Semiconductor Nanocomposites Using Monte Carlo Simulations, Mayank Malladi

All Theses

Nanocomposites are composite materials which incorporate nanosized particles, platelets or fibers. The addition of nanosized phases into the bulk matrix can lead to significantly different material properties compared to their macrocomposite counterparts. For nanocomposites, thermal conductivity is one of the most important physical properties. Manipulation and control of thermal conductivity in nanocomposites have impacted a variety of applications. In particular, it has been shown that the phonon thermal conductivity can be reduced significantly in nanocomposites due to the increase in phonon interface scattering while the electrical conductivity can be maintained. This extraordinary property of nanocomposites has been used to enhance …