Engineering Commons^™

Human-Robot Interaction For Assistive Robotics, Jiawei Li

Dissertations

This dissertation presents an in-depth study of human-robot interaction (HRI) withapplication to assistive robotics. In various studies, dexterous in-hand manipulation is included, assistive robots for Sit-To-stand (STS) assistance along with the human intention estimation. In Chapter 1, the background and issues of HRI are explicitly discussed. In Chapter 2, the literature review introduces the recent state-of-the-art research on HRI, such as physical Human-Robot Interaction (HRI), robot STS assistance, dexterous in hand manipulation and human intention estimation. In Chapter 3, various models and control algorithms are described in detail. Chapter 4 introduces the research equipment. Chapter 5 presents innovative theories and …

Experiments And Modeling Of The Chemo-Mechanically Coupled Behavior Of Polymeric Gels, Nikola Bosnjak

Dissertations

Polymeric materials consist of mutually entangled or chemically crosslinked long njitmolecular chains which form a polymer network. Due to their molecular structure, the njitpolymeric materials are known to undergo large deformation in response to various njitenvironmental stimuli, such as temperature, chemical potential and light.

When a polymer network is exposed to a suitable chemical solvent, the solvent molecules are able to diffuse inside the network, causing it to undergo a large volumetric deformation, known as swelling. In addition to volumetric deformation, this process involves the chemical mixing of the polymer network and solvent molecules, and is typically environmentally responsive. A …

Blast Shock-Wave Characterization In Experimental Shock Tubes, Sudeepto Kahali

Dissertations

Blast-induced traumatic brain injuries have affected U.S. soldiers deployed for extended periods in the gulf and Afghanistan wars. To identify the biomechanical and biochemical mechanisms of injury, critical in the identification of diagnostic and therapeutic tools, compressed gas-driven shock tubes are used by investigators to study shockwave-animal specimen interactions and its biological consequences. However, shock tubes are designed and operated in a variety of geometry with a range of process parameters, and the quality of shock wave characteristics relevant to field conditions and therefore the study of blast-induced traumatic brain injuries suffered by soldiers is affected by those conditions. Lab-to-lab …

Practical Adhesion Measurements In Organic Coatings; Advancing Understanding And Mechanical Methods Development, Diana Gottschalk

Dissertations

“Adhesion” can be considered either a mechanical or chemical phenomenon. The mechanical interpretation describes the difficulty of separating surfaces and is useful for quantifying performance within applications that depend on bulk and interfacial properties. Chemical adhesion describes interfacial resistance to chemical attack and does not depend on bulk properties. Predicting chemical failure through mechanical measurement is confounded by the influence of bulk properties. However, the prospect is attractive because of the robust tolerance for sample geometries, allowing experiments to resemble an end-use system. The present work's primary goal was to elevate mechanical methods to provide a detailed interfacial characterization of …

Resonant Triad Interactions In One And Two-Layer Systems, Malik Chabane

Dissertations

This dissertation is a study of the weakly nonlinear resonant interactions of a triad of gravity-capillary waves in systems of one and two fluid layers of arbitrary depth, in one and two-dimentions. For one-layer systems, resonant triad interactions of gravity-capillary waves are considered and a region where resonant triads can be always found is identified, in the two-dimensional wavevector angles-space. Then a description of the variations of resonant wavenumbers and wave frequencies over the resonance region is given. The amplitude equations correct to second order in wave slope are used to investigate special resonant triads that, providing their initial amplitude …

Turbulence Investigations In The Core-Flow Of An Internal Combustion Engine, James R. Macdonald

Dissertations

Turbulence significantly impacts the operation of energy conversion devices. In internal combustion (IC) engines, mixing, heat transfer, and combustion are all strongly dependent on the turbulence inside the cylinder. Consequently, knowledge of the state of turbulence is critical for improving our understanding and modeling of engine processes.

Turbulence states may be determined through analysis of the Reynolds stress tensor, which can in turn be experimentally quantified using velocity data. In this research, stereoscopic particle image velocimetry (stereo-PIV) experiments were conducted in a single-cylinder, motored engine with optical access to measure the two-dimensional, three-component (2D-3C) velocity fields throughout the compression stroke. …

Use Of Dimpling Techniques To Alter The Vibration And Acoustic Characteristics Of Beams And Plates, Mofareh Ghazwani

Dissertations

Structures such as beams and plates can produce potentially high levels of unwanted vibrations and noises in the environment. A method for improving the vibroacoustic characteristics of structures based on creating dimples on its surfaces is presented in this study. The goal of this technique is to keep the mass of the subject structure the same while changing its vibration and sound radiation characteristics. A boundary value model (BVM), derived using Hamilton’s Variational Principle, is used for modeling dimpled beams subjected to various boundary conditions. Using this method, the non-dimensional equations of motion, boundary conditions, and continuity conditions for a …

Experimental Study Of Collecting Running Water From Moderately Heated Water Vapors Using Turbulence-Induced Particles Collision (Tipc) Device, Hassan Ali Ghazwani

Dissertations

This dissertation describes the development of an alternative technique to collect water vapors or changing any vapor state to liquid state using a device called the turbulence-induced particles collision generator (TIPC). The experiment of collecting water vapors using the TIPC device is conducted at different values of temperature. The spatial patterns of droplets deposited on a wall due to the TIPC are measured at different values of pressure using luminescent oil technique, and the integrated intensity of deposited droplets is calculated. Also, the luminescent oil technique has been used to visualize the deposited particles on a pipe wall. ANSYS FLUENT …

Experimental And Numerical Investigation Of Free Water Surface Evaporation In Case Of Natural Convection, Hassan Fagehi

Dissertations

Evaporation of water can be considered an essential part of the hydrological cycle. It is important for many technological applications such as industrial cooling towers, air conditioning, solid material drying, distillation, and liquid film cooling. Moreover, the interfacial convection caused by the density gradient belongs to Rayleigh convection, which plays an important role in the evaporation process by means of intensifying heat and mass transfer, as in an isopropanol‒water system. In addition, natural convection, which can be defined as a buoyancy-driven flow, is important in astrophysics, geophysics, and numerous engineering applications such as solar energy systems, cooling of electrical equipment, …

Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii

Dissertations

The vulnerability of urban populations to natural hazards and climate change is a major theme in many reports on coastal cities with flooding ranking highly among the climate change concerns. Flooding could occur as a result of runoff for inland rainfall that accumulates at the mouth of the estuary to the sea or it could occur due to a storm surge emanating from the ocean. The techniques for modeling the flooding from these events are very different, as they were developed in different scientific fields: hydrology and hydraulic engineering for inland rainfall versus coastal oceanography and coastal engineering for offshore …

Mechanical Characterization Of Animal Derived Starting Materials For Tissue Engineering, Bin Zhang

Dissertations

Animal derived starting materials are well established in the production of Tissue Engineered Medical Devices. Porcine specifically can be found in products ranging in application from hernia repair to breast reconstruction. Although this material has been largely accepted in the Tissue Engineering industry, little is known of its material properties and mechanical characteristics. A review of the scientific literature describes limited mechanical measures only on uncontrolled research grade material. The objective of this work is to mechanically characterize porcine starting material used in the medical device industry. Porcine skin is provided by Midwest Research Swine, LLC (MRS) an established supplier …

Team Creation Methods In Practice: Understanding The Potential Effects Of Nonverbal Communication In The Leadership Of Team Formation, Troy Allen Robertson

Dissertations

Teams require leadership, even if they are self-managed. The group of individuals who make up a team must be gathered in some form or another. For self managed teams to function successfully, the first step is the process of creating the team. Many aspects may factor into the creation process. Often time is of the essence and methods to quickly assess and form teams show merit. First impressions in general are based largely on nonverbal communication. The focus of this mixed-methods concurrent embedded study is to analyze the potential effects of nonverbal communication on influencing team creation. A group of …

Evaporation Rate From Free Water Surface, Safa M. Aldarabseh

Dissertations

This work aims to perform an experiment in the laboratory and investigate the effect of the wave steepness, airflow velocity, air relative humidity, air temperature, and water surface temperature on the evaporation rate from still and wavy water surface. In this investigation, the experimental results are used to quantify an evaporation rate from a still and wavy water surface under different convection regimes that are free, mixed, and forced convection under turbulent airflow conditions. Empirical correlations are also derived using the experimental results based on modified Dalton’s law and Similarity method (analogy between mass and heat transfer equation). In this …