Mechanical Engineering Commons^™

Solar Power And The Electric Grid, Energy Analysis, Nrel Energy Analysis

Publications (E)

In today’s electricity generation system, different resources make different contributions to the electricity grid. This fact sheet illustrates the roles of distributed and centralized renewable energy technologies, particularly solar power, and how they will contribute to the future electricity system. The advantages of a diversified mix of power generation systems are highlighted.

Scaffold Based In-Vitro Osteodistraction For Bone Tissue Engineering, Cesar Adrian Terrazas

Open Access Theses & Dissertations

Engineering of hard tissues such as bone is a challenge because of the limited ability of the body to heal large defects. Current treatment options, such as employing bone sections from the patient or a deceased donor have been utilized for some time now with various degrees of success. However, these methods still exhibit many limitations such as limited supply and the possibility of transmission of disease.

To address the many limitations of bone grafts, synthetic engineered substitutes have been developed and widely researched for nearly three decades. Generally termed scaffolds, these are matrices that serve the purpose of temporary …

Dual Axis Solar Tracker, Weston Sapia, Jason Birnie

Electrical Engineering

No abstract provided.

Multidisciplinary Collaborative Model For Complex, Angel Ernesto Delgado

Open Access Theses & Dissertations

Nowadays, most devices with advanced technology require the development of embedded systems with mechanical and electrical components as well as software including more than one discipline. These are devices that are usually complex in terms of composition and functionality and that design must follow a methodology in order to successfully design and launch a device of this nature. Hence, the assembly of a multidisciplinary engineering group is required to carry out such complex devices and develop a fully functional product. The group may also need an expert on the field that can provide guidance and knowledge where needed. This is …

On The Effect Of Hydrodynamic Slip On The Polarization Of A Nonconducting Spherical Particle In An Alternating Electric Field, Hui Zhao

Mechanical Engineering Faculty Research

The polarization of a charged, dielectric, spherical particle with a hydrodynamically slipping surface under the influence of a uniform alternating electric field is studied by solving the standard model (the Poisson–Nernst–Planck equations). The dipole moment characterizing the strength of the polarization is computed as a function of the double layer thickness, the electric field frequency, the particle’s surface charge, and the slip length. Our studies reveal that two processes contribute to the dipole moment: ion transport inside the double layer driven by the electric field and the particle’s electrophoretic motion. The hydrodynamic slip will simultaneously impact both processes. In the …

Electro-Osmotic Flow Over A Charged Superhydrophobic Surface, Hui Zhao

Mechanical Engineering Faculty Research

Bubbles can be trapped inside textured structures such as grooves, forming a superhydrophobic surface. A superhydrophobic surface has a large effective hydrodynamic slip length compared to a smooth hydrophobic surface and holds the promise of enhancing electrokinetic flows that find many interesting applications in microfluidics. However, recent theoretical studies suggested that electro-osmotic flows over a weakly charged superhydrophobic surface

the zeta potential of the surface is smaller than the thermal potential (25 mV) can only be enhanced when liquid-gas interfaces are charged [T. M. Squires, Phys. Fluids 20, 092105 (2008); Bahga et al., J. Fluid Mech. 644, 245 (2010)]. So …

Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory

Publications (E)

The National Renewable Energy Laboratory (NREL) is the nation’s primary laboratory for renewable energy and energy efficiency research and development.

NREL’s mission and strategy are focused on advancing the U.S. Department of Energy’s and our nation’s energy goals. The laboratory’s scientists and researchers support critical market objectives to accelerate research from scientific innovations to market-viable alternative energy solutions. At the core of this strategic direction are NREL’s research and technology development competencies. These areas span from understanding renewable resources for energy, to the conversion of these resources to renewable electricity and fuels, and ultimately to the use of renewable electricity …

Near-Field Radiative Transfer: Thermal Radiation, Thermophotovoltaic Power Generation And Optical Characterization, Mathieu Francoeur

University of Kentucky Doctoral Dissertations

This dissertation focuses on near-field radiative transfer, which can be defined as the discipline concerned with energy transfer via electromagnetic waves at sub-wavelength distances. Three specific subjects related to this discipline are investigated, namely nearfield thermal radiation, nanoscale-gap thermophotovoltaic (nano-TPV) power generation and optical characterization. An algorithm for the solution of near-field thermal radiation problems in one-dimensional layered media is developed, and several tests are performed showing the accuracy, consistency and versatility of the procedure. The possibility of tuning near-field radiative heat transfer via thin films supporting surface phononpolaritons (SPhPs) in the infrared is afterwards investigated via the computation of …

The Influence Of Branches In The Performance Of Power-Line Communication Systems That Use Mc-Coma With Reed Solomon Coding, Emmanuel Felix

Tanzania Journal of Engineering and Technology (TJET)

Power-line network is proposed as an infrastructure for Information and Communications Technologies (ICTs)
services provision. However, there are a number of factors that contribute greatly to power-line communication performance degradation. These include number of branches that can be added or removed from the power- line network, lengths of the branch lines, loading etc. It has been pointed out that the number of branches is one of the factors that affects power-line performance to a certain extent. In this paper the influence of number of branches on the performance of Broadband Power-line communication (BPLC) that uses MC- CDMA modulation scheme with …

College Of Engineering Senior Design Competition Fall 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Each student in his or her senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. The senior design project encourages the student to use everything learned in the engineering program to create a practical, real-world solution to an engineering challenge.

A highlight of the year-long senior design project is the senior design competition. This competition, which usually takes place the week before finals each semester, helps focus the senior students on increasing the quality and potential for commercial application for their design projects.

Judges from local industry evaluate the projects on innovation, commercial …

Semi-Automatic Image Segmentation For Volumetric Visualization Of Pelvis Ct Scan-Images, Suprijanto Suprijanto, Farida I. Muchtadi, Irwan Setiawan

Makara Journal of Technology

Semi-Automatic Image Segmentation for Volumetric Visualization of Pelvis CT Scan-Images. The current development of computerized tomography (CT) has enable us to obtain cross sectional image using multi slicing techniques in an order of few seconds. The obtained images represent several tissue structures on cross section slice being imaged. One challenge to help diagnosis using CT images is extracting an anatomic structure of interest using a method of image segmentation and volumetric visualization with the assistance of computers. In case of volumetric visualization of pelvis bones extracted from multi-slice CT images, whole images which are containing part of pelvis bone structures …

Implementation Of Six Sigma Method To Maintain The Quality Of Construction Projects, Yusuf Latief, Retyaning Puji Utami

Makara Journal of Technology

Implementation of Six Sigma Method to Maintain The Quality of Construction Projects. Six sigma (6-sigma) is a method that widely developed in the world, especially in manufacturing industry to decrease failures in achieving good quality in construction projects. The objective of this research is to explore the existing condition of quality management and the aplication of 6-sigma method in maintaining quality of construction projects. Structured interviews to experienced experts and people who were recommended by their companies were conducted. Non-parametric analysis using frequencies distribution procedures were used for analysis. The result shows that existing condition in quality management of construction …

Mechanical Properties Of Ramie Fiber Reinforced Epoxy Lamina Composite For Socket Prosthesis, Tresna P. Soemardi, Widjajalaksmi Kusumaningsih, Agustinus Purna Irawan

Makara Journal of Technology

Mechanical properties of ramie fiber reinforced epoxy lamina composite for socket prosthesis. This paper presents an investigation into the application of natural fiber composite especially ramie fiber reinforced epoxy lamina composite for socket prosthesis. The research focuses on the tensile and shear strength from ramie fiber reinforced epoxy lamina composite which will be applied as alternative material for socket prosthesis. The research based on American Society for Testing Material (ASTM) standard D 3039/D 3039M for tensile strength and ASTM D 4255/D 4255M-83 for shear strength. The ramie fiber applied is a fiber continue 100 % Ne14'S with Epoxy Resin Bakelite …

Potency Of Thermoelectric Generator For Hybrid Vehicle, Nandy Putra, Raldi Artono Koestoer, Mohammad Adhitya, Ardian Roekettino, Bayu Trianto

Makara Journal of Technology

Potency of Thermoelectric Generator for Hybrid Vehicle. Thermoelectric Generator (TEG) has been known as electricity generation for many years. If the temperature difference occurred between two difference semi conductor materials, the current will flow in the material and produced difference voltage. This principle is known as Seebeck effect that is the opposite of Peltier effect Thermoelectric Cooling (TEC). This research was conducted to test the potential of electric source from twelve peltier modules. Then, these thermoelectric generators were applied in hybrid car by using waste heat from the combustion engine. The experiment has been conducted with variations of peltier module …

Effects Of Ph On Calcium Carbonate Precipitation Under Magnetic Field, Nelson Saksono, Yuliusman Yuliusman, Setijo Bismo, Roekmijati W. Soemantojo, Azwar Manaf

Makara Journal of Technology

Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3 solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In …

Performance Of Hollow Fiber Membrane Gas-Liquid Contactors To Absorb Co2 Using Diethanolamine (Dea) As A Solvent, Sutrasno Kartohardjono, Pan Ade Nata, Eko Prasetio, Yuliusman Yuliusman

Makara Journal of Technology

This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the …

Intermetallic Cu3sn Phase Layer On Electrode’S Tip Of Galvanized Resistance Spot Welding, Muhammad Anis, Aulia Irsyadi, Deni Ferdian

Makara Journal of Technology

Intermetallic Cu3Sn Phase Layer on Electrode’s Tip of Galvanized Resistance Spot Welding. A resistance spot welding method is commonly used in automotive industries application. In a resistance spot welding method, the copper electrode has a significant role as an electric current carrier for joining thin metal sheet. This research was focused on studying the effect of tin layer at the electrode tip for joining galvanized steel sheet. The main variable of this research is in the thickness of the intermetallic Cu3Sn layer. The result showed that the introduction of tin layer less than 1 μm in thickness on the electrode …

Simple Ml Detector For Multiple Antennas Communication System, Ahmad Taqwa, Soegijardjo Soegijoko, Sugihartono Sugihartono, Suhartono Tjondronegoro

Makara Journal of Technology

Simple ML Detector for Multiple Antennas Communication System. In order to support providing broadband wireless communication services against limited and expensive frequency bandwidth, we have to develop a bandwidth efficient system. Therefore, in this paper we propose a closed-loop MIMO (Multiple-Input-Multiple-Output) system using ML (Maximum Likelihood) detector to optimize capacity and to increase system performance. What is especially exciting about the benefits offered by MIMO is that a high capacity and performance can be attained without additional frequency-spectral resource. The grand scenario of this concept is the attained advantages of transformation matrices having capability to allocate transmitted signals power suit …

Shaped Mems Contact, Ronald A. Coutu Jr., Paul E. Kladitis, Robert L. Crane

AFIT Patents

A MEMS switch fabrication process and apparatus inclusive of a bulbous rounded surface movable contact assembly that is integral with the switch movable element and achieving of long contact wear life with low contact electrical resistance. The disclosed process is compatible with semiconductor integrated circuit fabrication materials and procedures and includes an unusual photoresist reflow step in which the bulbous contact shape is quickly defined in three dimensions from more easily achieved integrated circuit mask and etching-defined precursor shapes. A plurality of differing photoresist materials are used in the process. A large part of the contact and contact spring formation …

Reinforcement-Learning-Based Output-Feedback Control Of Nonstrict Nonlinear Discrete-Time Systems With Application To Engine Emission Control, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier

Electrical and Computer Engineering Faculty Research & Creative Works

A novel reinforcement-learning-based output adaptive neural network (NN) controller, which is also referred to as the adaptive-critic NN controller, is developed to deliver the desired tracking performance for a class of nonlinear discrete-time systems expressed in nonstrict feedback form in the presence of bounded and unknown disturbances. The adaptive-critic NN controller consists of an observer, a critic, and two action NNs. The observer estimates the states and output, and the two action NNs provide virtual and actual control inputs to the nonlinear discrete-time system. The critic approximates a certain strategic utility function, and the action NNs minimize the strategic utility …

Towards Supervised Autonomous Task Completion Using An In Vivo Surgical Robot, Jason J. Dumpert

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

Laparoscopy is a minimally invasive alternative to traditional abdominal surgery. Unlike traditional surgery, a laparoscopic procedure can be completed using small incisions. The use of these small incision results in reduced pain to the patient, shorter recovery times, and less trauma to skin, muscle and other tissues. However, these benefits to the patient are offset by the increased difficulty to the surgeon performing the procedure. These difficulties include reduced dexterity, reduced perception, and longer procedure times. The use of small in vivo robotic devices in minimally invasive surgery is one possible solution to these problems. The movement of these devices …

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …

Stability Analysis, Modeling, Simulation And Experimental Testing Of An Ems Maglev System With Structural Flexibility, Aravind M. Hanasoge

Mechanical & Aerospace Engineering Theses & Dissertations

Vehicle-guideway interaction studies of Magnetically Levitated (Maglev) vehicles indicate that structural flexibility can adversely affect the overall stability and performance of such systems. This is one of the reasons why guideways are generally made very rigid. This in turn leads to increased cost of the overall system since guideway construction forms a significant portion of the overall cost. In this dissertation, the influence of structural flexibility on the stability of Electromagnetic Suspension (EMS) Maglev systems is studied. It is shown how inherently unstable and flexible structure EMS Maglev systems can achieve guaranteed stability by using collocated actuators and sensors, along …

Dynamics And Control Of Cable-Drogue System In Aerial Recovery Of Micro Air Vehicles Based On Gauss's Principle, Liang Sun, Randal W. Beard, Mark B. Colton, Timothy W. Mclain

Faculty Publications

This paper presents a new concept for aerial recovery of Micro Air Vehicles (ARMAVs) using a large mothership and a recovery drogue. The mothership drags a drogue attached to a cable and the drogue is controlled to match the flight patten of the MAV. This paper uses Gauss’s Principle to derive the dynamic model of the cable-drogue systems. A controllable drogue plays a key role in recovering MAVs in windy conditions. We develop a control approach for the drogue using its drag coefficient. Simulation results based on multilink cable-drogue systems present the feasibility of the aerial recovery concept and the …

Biology-Inspired Adaptive And Nonlinear Robust Control Of Bauv Using Pectoral-Like Fins, Subramanian Ramasamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aquatic animals have splendid ability to move smoothly through water using variety of oscillating fins. Presently researchers are involved in developing biorobotic autonomous underwater vehicles (BAUVs) which have the ability to swim like marine animals. Multiple oscillating fins (dorsal, caudal, pectoral, pelvic, etc.) can be mounted on BAUVs to generate control forces for propulsion and maneuvering. In this research work, control of the BAUVs using pectoral fins alone is considered. The oscillating pectoral fins produce unsteady periodic forces. The control of motion of an BAUV in yaw and dive planes are considered.

College Of Engineering Senior Design Competition Spring 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

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. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Modulated Nanopores Using Pulse Anodization On Thin Aluminum, Mahesh Babu Gunukula

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nanoporous anodic aluminum oxide has traditionally been made in one of two ways: "Mild Anodization (MA)" or "Hard Anodization (HA)". The former method produces self-ordered pore structures but it is slow and only works for a narrow range of processing conditions; the latter method, which is widely used in the aluminum industry, is faster but it produces films with disordered pore structures. Here we report a novel approach termed "pulse anodization" that combines the advantages of the MA and HA processes. By designing the pulse sequences it is possible to control both the composition and pore structure of the anodic …

Payload Directed Flight Of Miniature Air Vehicles, Randal W. Beard, Clark Taylor, Jeff Saunders, Ryan Holt, Timothy W. Mclain

Faculty Publications

This paper describes three applications of payload directed flight using miniature air vehicles: vision-based road following, vision-based target tracking, and vision-based mapping. A general overview of each application is given, followed by simulation and flight-test results. Results demonstrate the viability of utilizing electo-optical video imagery to directly control the air vehicle flight path to enhance performance relative to the sensing objective.

Improved Predictive Power Control Of Cdma System In Rayleigh Fading Channel, Adit Kurniawan, Iskandar Iskandar, Sayid Machdar

Makara Journal of Technology

In this paper an improved prediction-based power control is proposed for code division multiple access (CDMA) systems in Rayleigh fading channel environments. One of the most serious problems which degrades the performance of power control algorithm is the effect of feedback delay. To overcome the effect of feedback delay, power control needs to employ prediction algorithm which utilises the correlation property of the past channel samples measurements to predict the future sample values. In CDMA power control, however, the correlation property of channel measurements is destroyed because the transmit power is continuously updated for each power control interval. The prediction …