Mechanical Engineering Commons^™

Microstructural Evolution Of Nanotwinned Al-Zr Alloy With Significant 9r Phase, N.A. Richter, Y.F. Zhang, D. Y. Xie, R. Su, Q. Li, S. Xue, T. Niu, J. Wang, H. Wang, Xinghang Zhang

Department of Mechanical and Materials Engineering: Faculty Publications

Aluminum (Al) alloys have a multitude of applications, notably in the automotive, aerospace and coating industries, yet they exhibit significantly lower mechanical strength than conventional steels. Nanotwins drastically improve mechanical strength while retaining ductility. However, the high SFE of Al largely prevents twinning. Here, we synthesize Al-Zr alloy films containing an abundance of incoherent twin boundaries and 9R phases. These alloys exhibit an extended solid solubility of Zr, retaining a columnar nanotwinned structure across all compositions. These films reach a hardness up to 4.2 GPa with 10 at% Zr and demonstrate the capacity for producing strong Al alloys with nanotwins.

Sensor Fusion And Non-Linear Mpc Controller Development Studies For Intelligent Autonomous Vehicular Systems, Ahammad Basha Dudekula

Dissertations, Master's Theses and Master's Reports

The demand for safety and fuel efficiency on ground vehicles and advancement in embedded systems created the opportunity to develop Autonomous controller. The present thesis work is three fold and it encompasses all elements that are required to prototype the autonomous intelligent system including simulation, state handling and real time implementation. The Autonomous vehicle operation is mainly dependent upon accurate state estimation and thus a major concern of implementing the autonomous navigation is obtaining robust and accurate data from sensors. This is especially true, in case of Inertial Measurement Unit (IMU) sensor data. The IMU consists of a 3-axis gyro, …

3d Printing Of Iron Oxide Incorporated Polydimethylsiloxane Soft Magnetic Actuator, Rasoul Bayaniahangar

Dissertations, Master's Theses and Master's Reports

Soft actuators have grown to be a topic of great scientific interest recently. As the fabrication of soft actuators with conventional microfabrication methods are tedious, expensive, and time consuming, employment of 3-D printing fabrication methods appears promising as they can simplify fabrication and reduce the production cost. Complex structures can be fabricated with 3-D printing such as helical coils can achieve actuation performances that otherwise would not be possible with simpler geometries. In this thesis development of soft magnetic helical coil actuators of iron-oxide embedded polydimethylsiloxane (PDMS) was achieved with embedded 3-D printing techniques. Composites with three different weight ratios …

Impact Of Considering And Neglecting States On Descent-To-Landing Navigation, Kyle J. Demars, Kari C. Ward

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper develops a novel square-root formulation of the consider/neglect Kalman filter for navigation applications. The proposed filter partitions system parameters into three distinct categories: those to be estimated by the filter, those whose contribution to the system can be considered without explicitly estimating them, and those with sufficiently low effect on the system such that their contribution can be neglected altogether. Discussion on appropriate selection of consider and neglect parameters is provided with specific attention given to descent-to-landing navigation. Monte Carlo simulations and analysis are performed to assess the performance of the square-root consider/neglect filter.

Design And Analysis Of Descent-To-Landing Navigation Incorporating Terrain Effects, Kari C. Ward, Gunner S. Fritsch, J. Cameron Helmuth, Kyle J. Demars, James S. Mccabe

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This study investigated the ability of a navigation filter to process multiple terrain-based sensors, such as slant-range, slant-speed, and terrain relative navigation sensors, during a descent-to-landing scenario to estimate the state of a landing vehicle. The filtering technique leveraged was based upon a factorized form of the multiplicative extended Kalman filter, and terrain-based measurements were fused with star camera and inertial measurement unit sensor returns to estimate the position, velocity, and attitude of the landing vehicle. Monte Carlo simulations were carried out to assess the performance of the navigation filter along a lunar descent trajectory, as well as the consistency …

Characterization And Recyclability Of 304l Stainless Steel Powder For Use In The Selective Laser Melting Process, Austin Taylor Sutton

Doctoral Dissertations

"Powder-bed fusion refers to a subset of additive manufacturing (AM) methods which successively melts and solidifies selected regions within a powder bed on a layer-by-layer basis to construct components directly from computer-aided design files. Laser Powder-Bed Fusion (L-PBF) is a process among the powder-bed fusion techniques that utilizes a laser to consolidate particles into a material with little porosity. During the L-PBF process, the large energy input from the laser causes the production of ejecta in the form of laser spatter and condensate, both of which have the potential to settle in the surrounding powder bed compromising its reusability. In …

Hydrokinetic Turbine Composite Blades And Sandwich Structures: Damage Evaluation And Numerical Simulation, Mokhtar Fal

Doctoral Dissertations

“Composite materials are gaining interest due to their high strength to weight ratio. This study deals with both experimental and numerical approaches to cover the aspects of the failure of composite materials in hydrokinetic turbine applications. In Part I, the location and magnitude of failure in the horizontal axis water turbine carbon fiber-reinforced polymer (CFRP) composite blades with different laminate stacking sequences were investigated. Two lay-up orientations were adopted for this work ([0⁰]₄ and [0⁰/90⁰]_2s). A finite element analysis model was generated to examine the stresses along the blade. Five angles were introduced to study the effect …

Investigation Of Vapor Deposited Conduction Seed Layer For Electrodeposition On Polymers, Olivia Bray

UNF Graduate Theses and Dissertations

The use of three-dimensional printing (3d printing) technologies are becoming increasingly popular in today’s society due to the time and cost advantages associated with these processes. In industries with a high demand for customizable and one-of-a-kind parts at a low volume, these additive manufacturing processes offer a promising solution. Surgical devices are a great example of this demand. Despite the advantages offered by 3d printing, the mechanical integrity of these 3d printed parts are often not comparable to the solid metal parts that have historically been used. In an effort to create a superior part and reach operational requirements, reinforcement …

Efficacy Of Hard Hats In Attenuating Head Accelerations: A Combined Experimental And Computational Investigation, Arthur Aloisio Alves Dos Santos

UNF Graduate Theses and Dissertations

Struck-by accidents are a leading cause of traumatic brain injuries in the construction industry. While hard hats are the conventional means of industrial head protection, the current test standard to evaluate hard hat performance does not assess their ability to mitigate head accelerations from such impacts. To address this gap in knowledge, three investigations were pursued as part of this thesis. First, a variety of commercially available hard-hat designs – differentiated by shell design, number of suspension points, and suspension tightening system – were tested for their ability to attenuate accelerations during vertical impacts to the head. All hard-hats appreciably …

Very High Cycle Fatigue Behavior Of Laser Beam-Powder Bed Fused Inconel 718 Considering The Layer Orientation And Surface Finish Effects, Palmer Frye

UNF Graduate Theses and Dissertations

Additive Manufacturing (AM) techniques have recently gained popularity for fabrication of parts used in aerospace applications. Some of these parts may be subjected to cyclic loading at very high frequencies, leading to service life requirements exceeding ten-million cycles (>10⁷ cycles). Therefore, understanding the very high-cycle fatigue (VHCF) behavior of these AM parts is an important step in their design and qualification processes. In this thesis, both high-cycle fatigue (HCF) and VHCF behaviors of Inconel 718, a Ni-base superalloy, manufactured via a Laser Beam-Powder Bed Fusion (LB-PBF) process, are investigated. Uniaxial, fully reversed force-controlled fatigue tests were conducted utilizing …

Efficient Enhancement Of Micro-Nucleation Rates In Flow-Boiling - By Concurrent Micro-Structuring Of The Boiling-Surface And Its Judicious Energization By Piezoelectric-Transducer Induced Acoustic Vibrations., Atharva Rahane

Dissertations, Master's Theses and Master's Reports

The report describes the science and technology backgrounds and uses for the technology breakthrough reported for enhanced flow-boiling based cooling of high-power density electronics (chips, memory etc.). A controlled but explosive growth in micro-scale nucleation rates during flow-boiling of HFE-7100 (electronics and environment friendly liquid from 3M, Inc) is enabled by the uses of inexpensive meshed-copper for micro-structuring of the boiling surface and a pair of Piezoelectric-transducers for active imposition of suitable acoustic vibrations. The pair of piezo transducers mounted just outside the mini-channel impose “in plane” acoustic vibrations of controllable amplitudes and frequencies, and they are used to induce …

Magnetic Control Of Transport Of Particles And Droplets In Low Reynolds Number Shear Flows, Jie Zhang

Doctoral Dissertations

“Magnetic particles and droplets have been used in a wide range applications including biomedicine, biological analysis and chemical reaction. The manipulation of magnetic microparticles or microdroplets in microscale fluid environments is one of the most critical processes in the systems and platforms based on microfluidic technology. The conventional methods are based on magnetic forces to manipulate magnetic particles or droplets in a viscous fluid.

In contrast to conventional magnetic separation method, several recent experimental and theoretical studies have demonstrated a different way to manipulate magnetic non-spherical particles by using a uniform magnetic field in the microchannel. However, the fundamental mechanism …

Development Of Horizontal Axis Hydrokinetic Turbine Using Experimental And Numerical Approaches, Abdulaziz Abutunis

Doctoral Dissertations

“Hydrokinetic energy conversion systems (HECSs) are emerging as viable solutions for harnessing the kinetic energy in river streams and tidal currents due to their low operating head and flexible mobility. This study is focused on the experimental and numerical aspects of developing an axial HECS for applications with low head ranges and limited operational space. In Part I, blade element momentum (BEM) and neural network (NN) models were developed and coupled to overcome the BEM’s inherent convergence issues which hinder the blade design process. The NNs were also used as a multivariate interpolation tool to estimate the blade hydrodynamic characteristics …

ผลกระทบของมุมของหลุมจุลภาครูปร่างสี่เหลี่ยมข้าวหลามตัดในการสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อ, ธนภัทร ชุนฟ้ง

Chulalongkorn University Theses and Dissertations (Chula ETD)

การศึกษานี้แบ่งออกเป็นสองวัตถุประสงค์หลัก วัตถุประสงค์แรกเป็นการศึกษาผลกระทบของมุมของหลุมจุลภาครูปร่างทรงพีระมิดฐานสี่เหลี่ยมข้าวหลามตัดทั้ง 3 รูปร่างคือ มุมแหลม (66 องศา) มุมด้านเท่า (90 องศา) และมุมป้าน (106 องศา) ต่อการสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อสำหรับการเลี้ยงที่ใช้การไหลแบบต่อเนื่อง โดยแต่ละหลุมจุลภาควางเรียงชิดกันเพื่อลดพื้นที่ว่างไม่ให้เซลล์ไปเกาะหรือเกิดการสูญเสียเซลล์ไป ในบริเวณก้นหลุมจุลภาคมีทรงกระบอกรัศมี 450 ไมโครเมตร ติดตั้งอยู่ ซึ่งเป็นตำแหน่งที่จะเกิดการสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อขึ้น และทำให้ความลึกรวมทั้งหมดของหลุมจุลภาคเท่ากับ 550 ไมโครเมตร ในการทดลองได้ใช้อัตราการไหลเท่ากับ 10 ไมโครลิตรต่อชั่วโมง ทั้งจากผลการคำนวณ และผลการทดลองพบว่า ในกรณีหลุมจุลภาคที่มีมุม 66 องศา ของไหลที่ไหลผ่านหลุมมีการเบี่ยงเบนทิศทางเข้าสู่กึ่งกลางหลุมมากกว่าหลุมแบบอื่น และน่าจะทำให้เกิดการสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อของเซลล์ลำบาก เพราะถูกรบกวนจากของไหลค่อนข้างสูง ในกรณีหลุมจุลภาคที่มีมุม 90 องศา ของไหลมีการเบี่ยงเบนทิศทางเข้าสู่กึ่งกลางลดลง ทำให้มีการสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อได้ดีขึ้น อย่างไรก็ตาม เมื่อหลุมจุลภาคมีมุม 106 องศา ของไหลมีการเบี่ยงเบนทิศทางเข้าหากึ่งกลางหลุมน้อยลงมาก ทำให้เซลล์บางส่วนไม่ถูกพัดพามารวมกันที่บริเวณก้นหลุมทรงกระบอก โดยเซลล์บางส่วนติดอยู่บนบริเวณผนังด้านข้าง ทำให้การสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อลดต่ำลง ดังนั้นผลการศึกษาจึงบ่งชี้ว่าหลุมจุลภาคทรงพีระมิดฐานสี่เหลี่ยมข้าวหลามตัดมุม 90 องศา มีความเหมาะสมที่สุดในการสร้างกลุ่มเซลล์คล้ายเนื้อเยื่อ นอกจากนั้น ผลการทดลองยังแสดงให้เห็นด้วยว่าอัตราการรอดชีวิตของเซลล์มีแนวโน้มดีกว่าหลุมจุลภาคแบบอื่นอีกด้วย วัตถุประสงค์ที่สองคือการสร้างระบบของไหลจุลภาคที่ใช้ต้นทุนต่ำ และรวดเร็ว โดยการสร้างแม่พิมพ์ด้วยการพิมพ์สามมิติด้วยเรซิ่น สำหรับการพิมพ์สามมิติจะทำให้สร้างแม่พิมพ์ที่มีรูปร่างที่ซับซ้อนมากได้ แต่ขนาดที่เล็กสุดยังจำกัดอยู่ และความแข็งแรงทางกล และความทนทานต่อความร้อนไม่ดีนัก อย่างไรก็ตาม วิธีการที่พัฒนาที่ขึ้นสามารถใช้งานได้ดีในการหล่อสารพอลิไดเมทิลซิโลเซนสำหรับระบบของไหลจุลภาค ซึ่งใช้งานอย่างมากในงานวิจัยทางด้านนี้

Development Of An Integrated Microfluidic System For Cell Sorting And Trapping—Considering Sorting Efficacy And Cell Viability, Thammawit Suwannaphan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study is divided into two phases. The first phase is about the investigation of cell viability and damage of white blood cells after sorting in both a spiral microchannel and contraction and expansion array (CEA) at appropriate flow rates for cell separation. Three techniques such as Trypan Blue staining, Scanning Electron Microscopy (SEM) and Wright-Giemsa staining are employed in the experiments. After flowing the sample through a whole setup of spiral microchannel at 2 ml/min, 85% of cells are viable while 30% of cells are significantly deformed and 2% of cells are seriously damaged in their intracellular structures. In …

Utility-Scale Solar Pv Performance Enhancements Through System Level Modifications, Andrew D. S. Glick, Naseem Ali, Juliaan Bossuyt, Marc Calaf, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Performance of solar PV diminishes with the increase in temperature of the solar modules. Therefore, to further facilitate the reduction in cost of photovoltaic energy, new approaches to limit module temperature increase in natural ambient conditions should be explored. Thus far only approaches based at the individual panel level have been investigated, while the more complex, systems approach remains unexplored. Here, we perform the first wind tunnel scaled solar farm experiments to investigate the potential for temperature reduction through system-level flow enhancement. The percentage of solar irradiance converted into electric power depends upon module efficiency, typically less than 20%. The …

Openfoam Simulations Of Late Stage Container Draining In Microgravity, Joshua Thomas Mccraney, Mark M. Weislogel, Paul Steen

Mechanical and Materials Engineering Faculty Publications and Presentations

In the reduced acceleration environment aboard orbiting spacecraft, capillary forces are often exploited to access and control the location and stability of fuels, propellants, coolants, and biological liquids in containers (tanks) for life support. To access the ‘far reaches’ of such tanks, the passive capillary pumping mechanism of interior corner networks can be employed to achieve high levels of draining. With knowledge of maximal corner drain rates, gas ingestion can be avoided and accurate drain transients predicted. In this paper, we benchmark a numerical method for the symmetric draining of capillary liquids in simple interior corners. The free surface is …

Modelling Lagrangian Velocity And Acceleration In Turbulent Flows As Infinitely Differentiable Stochastic Process, Bianca Fontanin Viggiano, Jan Friedrich, Romain Volk, Mickael Bourgoin, Raúl Bayoán Cal, Laurent Chevillard

Mechanical and Materials Engineering Faculty Publications and Presentations

We develop a stochastic model for Lagrangian velocity as it is observed in experimental and numerical fully developed turbulent flows. We define it as the unique statistically stationary solution of a causal dynamics, given by a stochastic differential equation. In comparison to previously proposed stochastic models, the obtained process is infinitely differentiable at a given finite Reynolds number, and its second-order statistical properties converge to those of an Ornstein-Uhlenbeck process in the infinite Reynolds number limit. In this limit, it exhibits furthermore intermittent scaling properties, as they can be quantified using higher-order statistics. To achieve this, we begin with generalizing …

การประมาณปริมาตรของมันสำปะหลังโดยใช้กล้อง Rgb-D, ชนิกานต์ บัญชาจารุรัตน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

มันสำปะหลังเป็นพืชที่ปลูกง่ายและปลูกเป็นจำนวนมากในประเทศไทย เครื่องมือที่เกี่ยวข้องในการตรวจวัดคุณภาพมันสำปะหลังหลังการเก็บเกี่ยวจนไปถึงก่อนแปรรูปที่ใช้ในปัจจุบันเป็นเครื่องมือที่ใช้หลักการวัดทางกลพื้นฐานและใช้ความรู้สึกของผู้ประเมินร่วมด้วย ทำให้มีโอกาสที่จะได้ผลประเมินที่ไม่เป็นความจริง วิทยานิพนธ์นี้เสนอแนวทางการตรวจวัดคุณภาพมันสำปะหลังในห่วงโซ่อุปทานโดยใช้กล้อง Kinect ซึ่งเป็นกล้อง RGB-D ถ่ายรูปภาพของหัวมันสำปะหลังเพื่อหาปริมาตรของมันสำปะหลัง การศึกษาทำโดยถ่ายภาพมันสำปะหลังพันธุ์เกษตรศาสตร์ 50 จำนวน 90 ตัวอย่างแล้วนำมาวิเคราะห์หาปริมาตรด้วยโปรแกรม MATLAB และใช้วิธีการประมาณปริมาตรมันสำปะหลัง 2 วิธีได้แก่ การประมาณปริมาตรโดยใช้ Depth image และการประมาณปริมาตรโดยใช้ Point Cloud image ทั้งสองวิธีการนี้มีพื้นฐานมาจากการหาปริมาตรของรูปทรงเรขาคณิต ผลการหาปริมาตรของมันสำปะหลังจากการประมาณด้วยวิธีการ depth image และวิธีการ point cloud image เมื่อนำมาพล็อตกับปริมาตรของมันสำปะหลังที่ได้จากวิธีการแทนที่น้ำให้ค่าความคลาดเคลื่อน RMSE เท่ากับ 66.94 มิลลิลิตรและ 41.4 มิลลิลิตร หรือคิดเป็นร้อยละ 21.12 และ 13.06 ตามลำดับเมื่อเทียบกับค่าเฉลี่ยของปริมาตรของหัวมันสำปะหลังจากวิธีการแทนที่น้ำ และค่า R-squared ที่ได้จากการประมาณทั้งสองวิธีมีค่า 0.9561 และ 0.9626 ดังนั้นจึงสรุปได้ว่าการประมาณปริมาตรหัวมันสำปะหลังด้วยวิธีการใช้รูป point cloud จะดีกว่าจากค่า R-squared ที่มากกว่าและค่า RMSE ที่น้อยกว่า ปริมาตรของมันสำปะหลังที่ประมาณด้วยรูปถ่ายนี้สามารถนำไปประยุกต์หาเปอร์เซ็นต์แป้งมันสำปะหลังได้

Artificial Intelligence In Plasma Electrolytic Micro-Oxidation For Surface Hardening - Insights From Scholarly Citation Networks And Patents., Priya Jadhav, Dr.Arun Bongale, Dr.Satish Kumar, Dr.Amit Kumar Tiwari

Library Philosophy and Practice (e-journal)

Objective - The purpose of this article is to analyze the top work areas and patent domains in the field of surface hardening by micro-arc oxidation. Also, it is directed on the opportunities of data analysis by different machine learning tools. Material and methods - The www.lens.org database is used to collect articles from Elsevier, Trans tech publications, Springer New York, MDPI, etc. to review the relevant articles as well as patents related to the topic. The result - A total of 1057 articles were published in 60 different journals and 756 patents in the area of research under various …

Bibliometric Analysis Of Bearing Fault Detection Using Artificial Intelligence, Pooja Kamat, Rekha Sugandhi Dr.

Library Philosophy and Practice (e-journal)

The new industrial revolution called Industry 4.0 is proliferating at its peak. The time is no longer away when the human race is going to witness a huge paradigm shift. Intelligent machines empowered by Artificial Intelligence (AI)will take over the presence of human workers in the industrial manufacturing sector with the target of achieving 100% automation. With the emergence of cut-throat price competition in the product market, it has become equally important to manufacture goods at minimal costs and with the highest quality. Predicting the decrease in machinery efficiency at an earlier stage to accomplish this objective helps to reduce …

Observer-Based Event-Triggered And Set-Theoretic Neuro-Adaptive Controls For Constrained Uncertain Systems, Abdul Ghafoor

Doctoral Dissertations

"In this study, several new observer-based event-triggered and set-theoretic control schemes are presented to advance the state of the art in neuro-adaptive controls. In the first part, six new event-triggered neuro-adaptive control (ETNAC) schemes are presented for uncertain linear systems. These comprehensive designs offer flexibility to choose a design depending upon system performance requirements. Stability proofs for each scheme are presented and their performance is analyzed using benchmark examples. In the second part, the scope of the ETNAC is extended to uncertain nonlinear systems. It is applied to a case of precision formation flight of the microsatellites at the Sun-Earth/Moon …

Combustion And Emission Characteristics Of Ic Engines Fueled By Hydrogen And Hydrogen/Diesel Mixtures And Multi-Objective Optimization Of Operating Parameters, Abdulhakim Issa Jabbr

Doctoral Dissertations

“The present study considers combustion of hydrogen in IC engines. In general, the work focuses on simulating the engine performance and emissions at different operation parameters, and using optimization techniques. Task I work deals with the engine performance and emissions of a single cylinder spark-ignition (SI) engine fueled by hydrogen. The engine was simulated at different equivalence ratios, exhaust gas recirculation (EGR) and ignition timing. The results indicate that NOx emissions, engine power, and efficiency are reduced by increasing EGR level, and increased with increasing equivalence ratio and advanced ignition timing. The best operating conditions for hydrogen engines were obtained …

Theoretical Investigation Of The Low Frequency Fundamental Mechanism Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard

Études primaires

The objective occlusion effect induced by bone-conducted stimulation refers to the low frequency acoustic pressure increase that results from occluding the ear canal opening. This phenomenon is commonly interpreted as follows: the bone-conducted sound “leaks” through the earcanal opening and is “trapped” by the occlusion device. This instinctive interpretation misrepresents the fundamental mechanism of the occlusion effect related to the earcanal impedance increase and already highlighted by existing electro-acoustic models. However, these models simplify the earcanal wall vibration (i.e., the origin of the phenomenon) to a volume velocity source which, in the authors' opinion, (i) hinders an exhaustive comprehension of …

A Dynamic Neural Network Designed Using Analytical Methods Produces Dynamic Control Properties Similar To An Analogous Classical Controller, Wade William Hilts, Nicholas Szczecinski, Roger Quinn, Alexander Hunt

Mechanical and Materials Engineering Faculty Publications and Presentations

Human balance is achieved using many concurrent control loops that combine to react to changes in environment, posture, center of mass and other factors affecting stability. Though numerous engineering models of human balance control have been tested, no methods for porting these models to a neural architecture have been established. It is our hypothesis that the analytical methods we have developed, combined with classical control techniques will provide a reasonable starting point for developing dynamic neural controllers that can reproduce classical control capabilities. In previous work, we tested this hypothesis and demonstrated that a biologically-constrained neural controller that replicates human …

Computational Fluid Dynamics Study Of The Effects Of Secondary Flows In 90-Degree Pipe Elbow Erosion, O. Ayala, G. Rivera-Hernández, C. Knight

Engineering Technology Faculty Publications

Computational fluid dynamics (CFD) of particle-laden fluid flows through a 90-degree pipe elbow at Reynolds numbers 1,000 and 10,000 were completed; for different dimensionless elbow curvature ratios of 1.0, 1.5, and 2.5; and for particles with different Stokes numbers of 0.01, 0.1, 0.5, 1.0, 5.0, and 10.0. There were two scenarios in the study. For the first, the particles felt drag from the primary (or the axial) flow as well as from the secondary fluid flows in the elbow. For the second, the secondary fluid flow in the 90-degree bend was suppressed from the particle drag, thus the particles only …

Partnering Undergraduate Engineering Students With Preservice Teachers To Design And Teach An Elementary Engineering Lesson Through Ed+Gineering, Kristie Gutierrez, Stacie I. Ringleb, Jennifer Jill Kidd, Orlando M. Ayala, Pilar Pazos, Krishnanand Kaipa

Teaching & Learning Faculty Publications

Major challenges in engineering education include retention of undergraduate engineering students (UESs) and continued engagement after the first year when concepts increase in difficulty. Additionally, employers, as well as ABET, look for students to demonstrate non-technical skills, including the ability to work successfully in groups, the ability to communicate both within and outside their discipline, and the ability to find information that will help them solve problems and contribute to lifelong learning. Teacher education is also facing challenges given the recent incorporation of engineering practices and core ideas into the Next Generation Science Standards (NGSS) and state level standards of …

Effect Of Flow Velocity And Geometry On The Signal From A Piezoelectric Flow Rate Sensor, Jad Gerges Aboud

Open Access Theses & Dissertations

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Accurate Replication Of An Ear Pinnae Geometry For Use In Acoustic Testing Of Spatial Cues And Sound Localization, Alejandra Belmont

Open Access Theses & Dissertations

Additive manufacturing (AM) enables freedom of design as well as fabrication of complex objects such as the human hear. In medical modeling there is a need for patient-specific customizable parts. The outer human ear consists of these main parts: the pinna, which naturally filters sound, and the ear canal, which is the point at which sound enters before being moved up to the tympanic membrane, otherwise known as the eardrum. In an attempt to accurately replicate ear models, the use of scanning and reverse engineering methods was used. A comparison of 3D laser scanning systems was performed to determine their …

Design And Additive Manufacturing Of Shape Recovery Polymer Lattice Structure, Chien-Chun Chou

Open Access Theses & Dissertations

Studied mechanical properties of 3D printed metamaterials of BCC, FCC, and BFCC structure.