Mechanics of Materials Commons^™

Evaluation Of Peritoneal Microbubble Oxygenation Therapy In A Rabbit Model Of Hypoxemia, Nathan D. Legband, Jameel A. Feshitan, Mark A. Borden, Benjamin S. Terry

Department of Mechanical and Materials Engineering: Faculty Publications

Alternative extrapulmonary oxygenation technologies are needed to treat patients suffering from severe hypoxemia refractory to mechanical ventilation. We previously demonstrated that peritoneal microbubble oxygenation (PMO), in which phospholipid-coated oxygen microbubbles (OMBs) are delivered into the peritoneal cavity, can successfully oxygenate rats suffering from a right pneumothorax. This study addressed the need to scale up the procedure to a larger animal with a splanchnic cardiac output similar to humans. Our results show that PMO therapy can double the survival time of rabbits experiencing complete tracheal occlusion from6.6 ± 0.6 min for the saline controls to 12.2 ± 3.0 min for the …

Efficiency Enhancement In Polymer Solar Cells With A Polar Small Molecule Both At Interface And In The Bulk Heterojunction Layer, Zhengguo Xiao, Qingfeng Dong, Qi Wang, Wenjing Tian, Hui Huang, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The polar molecules, including ferroelectric materials with large dipole moments, have been applied as interfacial layers to increase the efficiency of organic solar cells by increasing the bounded charge separation, tuning the energy levels, etc. Here, we report a small polar molecule 2-cyano-3- (4-(diphenylamino) phenyl)acrylic acid (TPACA) that can be either blended in the active layer or at the polymer/electrode interface to increase the efficiency of organic solar cell devices after poling. It is found that the built-in potential of the device is increased by 0.2 V after poling under negative bias. Blending TPACA into the active layer has shown …

Towards Tuning The Mechanical Properties Of Three-Dimensional Collagen Scaffolds Using A Coupled Fiber-Matrix Model, Shengmao Lin, Lauren A. Hapach, Cynthia Reinhart-King, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Scaffold mechanical properties are essential in regulating the microenvironment of three-dimensional cell culture. A coupled fiber-matrix numerical model was developed in this work for predicting the mechanical response of collagen scaffolds subjected to various levels of non-enzymatic glycation and collagen concentrations. The scaffold was simulated by a Voronoi network embedded in a matrix. The computational model was validated using published experimental data. Results indicate that both non-enzymatic glycation-induced matrix stiffening and fiber network density, as regulated by collagen concentration, influence scaffold behavior. The heterogeneous stress patterns of the scaffold were induced by the interfacial mechanics between the collagen fiber network …

Laparoscopic Devices And Methods Of Using, M. Susan Hallbeck, Jakeb Riggle, Adam De Laveaga, Jake Kaufman

Department of Mechanical and Materials Engineering: Faculty Publications

A number of improvements to laparoscopic devices are described herein, primarily to improve the ergonomic functionality of the devices. For example, an articulating rod system is described, a gripping mechanism is described, and an end effector is described

Two-Dimensional Scalar Differential Equations For Transversely Varying Thickness Modes In Piezoelectric Plates And Applications In Acoustic Wave Resonator Sensors, Huijing He

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

Generalizations are made for three types of well-known and widely used twodimensional scalar differential equations in the literature describing transversely varying thickness modes in piezoelectric plate resonators. They are for singly-rotated quartz plates, doubly-rotated quartz plates, and plates of crystals of class 6mm with the c-axis along the plate thickness, respectively. The purpose of the generalizations is to include the effects of surface mechanical loads such as mass layers or fluids for resonator -based acoustic wave sensor applications. Surface acoustic impedance is introduced to take into account various surface loads in a general manner for time-harmonic motions. Both unelectroded and …

High Strength Steel Fiber Reinforced Flow-Able Or Scc Concrete With Variable Fiber By Volume Fractions For Thin Plate And Shell Structures, Abebe Berhe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to incorporate discrete, short, mechanically deformed, small diameter steel fibers into high strength concrete with f'c > 70 MPa (10 ksi) in an attempt to reduce and partially eliminate the need for steel rebar in concrete construction. By introducing steel fibers to high strength concrete mixture, the overall tensile, compressive and shear strength of the mixture can be improved immensely thus, replacing portions or major parts of the longitudinal, temperature and shrinkage reinforcements. The reduction or elimination of longitudinal and transverse reinforcements in the construction of structural or non-structural members can result in savings in …

Modular And Cooperative Medical Devices And Related Systems And Methods, Shane M. Farritor, Mark Rentschler, Amy Lehman

Department of Mechanical and Materials Engineering: Faculty Publications

The various embodiments disclosed herein relate to modular medical devices, including various devices with detachable modular components and various devices with pivotally attached modular components. Additional embodiments relate to procedures in which various of the devices are used cooperatively. Certain embodiments of the medical devices are robotic in vivo devices.

Biphilic Nanoporous Surfaces Enabled Exceptional Drag Reduction And Capillary Evaporation Enhancement, Xianming Dai, Fanghao Yang, Ronggui Yang, Xinyu Huang, William A. Rigdon, Xiaodong Li, Chen Li

Faculty Publications

Simultaneously achieving drag reduction and capillary evaporation enhancement is highly desired but challenging because of the trade-off between two distinct hydrophobic and hydrophilic wettabilities. Here, we report a strategy to synthesize nanoscale biphilic surfaces to endow exceptional drag reduction through creating a unique slip boundary condition and fast capillary wetting by inducing nanoscopic hydrophilic areas. The biphilic nanoporous surfaces are synthesized by decorating hydrophilic functional groups on hydrophobic pristine multiwalled carbon nanotubes. We demonstrate that the carbon nanotube-enabled biphilic nanoporous surfaces lead to a 63.1% reduction of the friction coefficient, a 61.7% wetting speed improvement, and up to 158.6% enhancement …

Characterization Of Wide Band Gap Semiconductors And Multiferroic Materials, Bo Cai

Dissertations, Theses, and Capstone Projects

Structural, optical and electrical properties of zinc oxide (ZnO), aluminum nitride (AlN), and lutetium ferrite (LuFe₂O4) have been investigated. Temperature dependent Hall Effect measurements were performed between 80 and 800 K for phosphorus (P) and arsenic (As) doped ZnO thin films grown on c-plane sapphire substrate by RF magnetron sputtering. These samples exhibited n-type conductivity throughout the temperature range with carrier concentration of 3.85 × 10 ¹⁶ cm^-3 and 3.65 × 10 ¹⁷ cm^-3 at room temperature for P-doped and As-doped ZnO films, respectively. The Arrhenius plots of free electron concentration of those doped samples showed …

Design Of Well-Defined Mesoporous Silicas Via Surfactant Templating Method Enhanced By The Use Of Swelling Agents, Tiffany Man

Dissertations, Theses, and Capstone Projects

Surfactant-templated ordered mesoporous materials continue to attract tremendous attention as these materials are characterized by reproducibility and predictability of their synthesis as well as their wide range of potential applications, which serve as future opportunities for additional advancement. The main purpose of this dissertation is to advance the understanding how to control the structural features and properties in the synthesis of well-defined porous materials via surfactant templating method, while keeping in mind that the uniformity of pore size and structural ordering are essential characteristics for these well-defined materials. The work was primarily focused on the issue of the unit-cell size …

Synthesis And Evaluation Of Sensitizer Drug Photorelease Chemistry: Micro-Optic Method Applied To Singlet Oxygen Generation And Drug Delivery, Goutam Ghosh

Dissertations, Theses, and Capstone Projects

This thesis summarizes a new micro-optic method for singlet oxygen generation and sensitizer drug delivery, which include i) synthesis and evaluation of a first generation device for drug delivery from native and fluorinated silica probe tips, ii) synthesis of PEG conjugated sensitizers to study phototoxicity in ovarian cancer cells, and iii) synthesis and evaluation of tris-PEGylated chlorin conjugated fluorinated silica for its future integration into the device to use as a 2nd generation device. A first generation micro-optic device was developed that works by sparging O2 gas and light generating cytotoxic singlet oxygen that cleaves the covalently attached drug (sensitizer) …

Synthesis, Fabrication And Characterization Of Magnetic And Dielectric Nanoparticles And Nanocomposite Films, Xiaohua Liu

Dissertations, Theses, and Capstone Projects

Materials science is an interdisciplinary field investigating the structure-property relationship in solid-state materials scientifically and technologically. Nanoscience is concerned with the distinctive properties that matter exhibits when confined to physical dimensions on the order of 10^-9 meters. At these length scales, behaviors of particles or elaborate structures are often governed by the rules of quantum mechanics in addition to the physical properties associated with the bulk material.

The work reported here seeks to employ nanocystals, binary nanocomposites and thin films of materials, to build versatile, functional systems and devices. With a focus on dielectric, ferroelectric, and magnetoelectric performance, a …

Metal Nanoparticles Immobilized On Basic Supports As Catalysts For Hydrogenation And Dehydrogenation Reactions Of Relevance To Cleaner Fossil Fuels And Alternative Sources Of Energy, Reena Rahi

Dissertations, Theses, and Capstone Projects

We developed a series of catalysts, composed of metal nanoparticles immobilized on basic supports for the hydrogenation of heteroaromatics of relevance to cleaner fossil fuels and biodiesel, and for the dehydrogenation of heteroaromatics of relevance to hydrogen storage in organic liquids. Our catalyst design involves nanostructured catalysts composed of metal particles immobilized on basic supports capable of ionic mechanism that may avoid catalyst poisoning and enhance catalytic activity.

We prepared a new catalyst composed of Pd nanoparticles immobilized on MgO by NaBH4 reduction of Na2PdCl4 in methanol in the presence of the support. TEM measurements revealed well-dispersed 1.7 nm Pd …

Lightweight Uav Launcher, Ben Miller, Christian Valoria, Corinne Warnock, Jake Coutlee

Mechanical Engineering

This report discusses the design, construction, and testing of a lightweight, portable UAV launcher. There is a current need for a small team of soldiers to launch a US Marine Tier II UAV in a remote location without transport. Research was conducted into existing UAV launcher designs and the pros and cons of each were recorded. This research served as a basis for concept generation during the initial design development stage. It was required that the design weigh less than 110 lbs, occupy a smaller volume than 48" x 24" 18" in its collapsed state, be portable by a single …

Modification Of A Draw Bar Type Arena Harrow To Three Point Mounted Type Harrow, Clayton Alan Brown

BioResource and Agricultural Engineering

This senior project will be the design, and construction of a three point hitch to be attached to a draw bar type spike tooth harrow. Currently used by the Cal Poly Rodeo Team to cultivate their arena before performances, and practices.

The attachment will allow the harrow to be pulled in both directions to create different types of soil affects.

Also the fabrications has a minimal budget so the majority of the materials will be scrap material already in position of the rodeo team or donated to the project.

Handloaded Rifle Ammunition: A Look Into The Assembly Process, Load Development Methods, And Its Comparison To Factory Ammunition, Jeffrey Dalton Snyder

Senior Theses

The purpose of this thesis is to educate the reader on the appeal of assembling firearm ammunition from its individual components, a process known as “handloading,” in comparison to factory assembled ammunition. This is accomplished by providing the reader with the benefits of handloading with an overview of the handloading process. Then, an example of a handload development method (Ladder Test) is discussed and performed. The results from the test are then analyzed and explained. Finally, the handloaded ammunition from the test is compared by function and price to factory ammunition from three different market segments.

The project portion of …

Design Of A Uv Curing Cartridge For 3d Inkjet Printing, Richard Wiswell

Thinking Matters Symposium Archive

In printing multi-layer electronic circuits, each layer must be formed as a continuous pattern in high resolution from ink jetted liquid droplets and be in precise alignment with the other layers, precluding substrate removal for UV curing. This research seeks to determine the optimal method for in-situ UV curing of the ink jetted material in a single pass. The inkjet replacement cartridge designed for this purpose was constructed of aluminum, fit into the printer head assembly in good alignment with the other ink cartridges, and contained a UV LED for in-situ curing and a cooling fan to maintain safe operating …

Detailed Finite Element Analysis And Preliminary Study Of The Effects Of Friction And Fastener Pre-Tension On The Mechanical Behavior Of Fastened Built-Up Members, Francisco Javier Bonachera Martin

Open Access Theses

The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted …

Experimental Investigation Of Mechanical Behavior Of An Oxide/Oxide Ceramic Composite In Interlaminar Shear And Under Combined Tension-Torsion Loading, Skyler R. Hilburn

Theses and Dissertations

Creep behavior in interlaminar shear of an oxide-oxide ceramic composite, Nextel 720™/aluminosilicate (N720/AS), was investigated at 1100°C in laboratory air and in steam. The interlaminar shear strength (ILSS) was determined as 7.65 MPa. The creep behavior was examined for interlaminar shear stresses in the 2-6 MPa range. Primary and secondary creep regimes were observed in all tests conducted in air and in steam. Tertiary creep was noted in the tests performed at 6 MPa. Larger creep strains and higher creep strain rates were produced in steam. Surprisingly, the presence of steam had a beneficial effect on creep lifetimes. It appears …

Passive Biaxial Mechanical Properties And In Vivo Axial Pre-Stretch Of The Diseased Human Femoropopliteal And Tibial Arteries, Alexey Kamenskiy, Iraklis I. Pipinos, Yuris A. Dzenis, Clay Lomneth, Syed A. Jaffar Kazmi, Nicholas Y. Phillips, Jason N. Mactaggart

Department of Mechanical and Materials Engineering: Faculty Publications

Surgical and interventional therapies for atherosclerotic lesions of the infrainguinal arteries are notorious for high rates of failure. Frequently, this leads to expensive reinterventions, return of disabling symptoms, or limb loss. Interaction between the artery and repair material likely plays an important role in reconstruction failure, but data describing the mechanical properties and functional characteristics of human femoropopliteal and tibial arteries are currently not available. Diseased superficial femoral (SFA, n=10), popliteal (PA, n=8), and tibial arteries (TA, n=3) from 10 patients with critical limb ischemia were tested to determine passive mechanical properties using planar biaxial extension. All …