Engineering Commons^™

Stochastic Lightning Damage Prediction Of Carbon/Epoxy Composites With Material Uncertainties, S.Z.H. Shah, Juhyeong Lee

Mechanical and Aerospace Engineering Faculty Publications

This study presents a novel stochastic modeling framework predicting lightning thermal damage in carbon/epoxy composites. The stochastic lightning damage model (SLDM) was developed with random distributions of composite’s electrical conductivity and void. The Box-Muller transformation was applied to generate random in-plane and through-thickness electrical conductivities with Gaussian distributions. The SLDM suggested that the predicted lightning thermal damage to carbon/epoxy composites increased slightly with the use of stochastic electrical conductivity, but the presence of voids did not significantly affect the damage development. The predicted size and shape of lightning thermal damage agreed fairly well with experimental results. In addition, the proposed …

Design Survey Of Laminated Composite I-Beam, Mrinmoy Saha

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing …

Technical Developments In Fish Exclusion, Guidance, And Collection Materials, A. L. Peters

International Symposium on Hydraulic Structures

Construction of mills, dams and other structures in rivers and streams, and the withdrawal of water for irrigation or cooling industrial facilities vital to social and economic progress, have impacted the survival of marine life. Barriers and guidance or collection nets can protect fish and aquatic species while allowing water to flow unimpeded for commercial and industrial use. However, nets can attract aquatic growth, fill with debris, degrade with environmental stress, and be expensive to operate and maintain.

A closer look at the technical developments of materials and net designs in diverse settings can offer guidance that will be of …

Thermal Property Measurement Of Thin Fibers By Complementary Methods, Troy Robert Munro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thin fibers are prevalent in many engineering materials. Measuring how well heat transfers in such small fibers can be difficult to determine, and previous methods have led to erroneous results. This dissertation details three proposed methods to improve the measurement of the thermal conductivity, thermal diffusivity, and volumetric heat capacity of thin fibers. Of particular interest is natural and synthetic spider silks because previously published values of the natural silk thermal conductivity was similar to copper, an excellent thermal conductor.

The three methods developed are the improved transient electrothermal technique (which was redeveloped to include radiation and convection heat losses …

Methods For Growing Retinal Pigment Epithelial Cells: Current Protocols And Future Recommendations, Aaron H. Fronk

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The retinal pigment epithelium (RPE) is a layer of tissue found in the vertebrate eye between Bruch’s membrane and the photoreceptor layer of the neural retina [1]. It is derived from the outer layer of the optic cup [2], possesses an innate immune system [3], and consists of a monolayer of highly pigmented cells that fit together in a tight matrix (fig. 1) [4]–[6]. The monolayer is often compared to a mosaic or cobblestones in its configuration, while the shape of the individual cells is usually described as polygonal/hexagonal, columnar (aligned perpendicular to the underlying membrane), or “epithelioid”. The cells …

Designing A Clarifier To Recover Wastewater Algae Biomass For Production Of Biofuels, Elizabeth Martinez

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Logan Lagoons, Logan City’s Wastewater Treatment Facility ensures 15 million gallons of wastewater are cleaned and filtered each day. With the implementation of new and stricter wastewater effluent standards, the city of Logan now has to guarantee the phosphorous concentration in the effluent is also reduced. Algal biomass produced and harvested from the lagoons has been proven to affect the way nitrogen and phosphorous are removed, while having the potential to be converted to biofuels. Therefore, implementing a secondary type clarifier in the Logan Lagoons would produce treated water with a reduced phosphorous concentration, and algae feedstock for biofuel …

Surface-Enhanced Raman Spectroscopy-Based Biomarker Detection For B-Cell Malignancies, Nathan Israelsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

B-cells are responsible for the production of antibodies and the recognition of dangerous pathogens. When B-cells become cancerous, they no longer perform these vital functions. This reduced B-cell activity results in greater susceptibility to opportunistic infections and increasing health risks. To effectively care for different cancer subtypes, targeted diagnosis and treatment is required. To determine the specific B-cell cancer type, up to twenty different cancer biomarkers on the cell surface need to be detected at the same time. Traditional methods are not capable of detecting such a large number of biomarkers simultaneously. This paper presents the design of a system …

Observations On Braided Thin Wire Nucleate Boiling In Microgravity, Justin P. Koeln, Jeffrey C. Boulware, Heng Ban, Jr Dennison

Publications

A microgravity experiment was conducted on the Space Shuttle Endeavor (STS-108) to observe sustained nucleate boiling of water. Subcooled water was boiled with a single strand and a braid of three 0.16. mm diameter and 80. mm long Nichrome resistive wires. A CCD video camera recorded the experiment while six thermistors recorded the temperature of the fluid at various distances from the heating element. This paper reports experimental results in observations, measurements, and data analysis. Bubble explosions were found to take place shortly after the onset of boiling for both the single and braid of wires. The explosion may produce …

In-Pile Thermal Conductivity Measurement Methods For Nuclear Fuels, Brandon S. Fox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measuring nuclear fuel thermal conductivity in-pile can provide much needed data for understanding fuel performance during irradiation and yield thermophysical property data needed for simulation codes and fuel databases. The objective of this research is to develop and compare two in-pile thermal conductivity methods in a laboratory setting using surrogate fuel materials.

A steady-state radial heat flow method was investigated to understand its viability as an in-pile steady-state thermal conductivity technique. By using Joule heating to simulate volumetric heat generation within a surrogate fuel rod, thermal conductivity was measured with two thermocouples at different radial positions within the rod. Examinations …

Intergranular Phases In Cyclically Annealed Yba2cu3o7-X And Their Implications For Critical Current Densities, Andrew Peter Clarke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We report changes in the intergranular material and grain morphology of YBa₂Cu₃O_7-x during cyclic anneals between 780 and 980 ºC in oxygen at atmospheric pressure. Two endothermic reactions were detected: (a) the eutectic reaction of YBa₂Cu₃O_7-x with CuO and BaCuO₂ at 900 ºC (enthalpy ∆H_a) and (b) the peritectic reaction of YBa₂Cu₃O_7-x with CuO at 950 ºC (∆H_b). During the first anneal, only reaction (b) is detected, and although it should only occur if there is an excess of CuO, …

A Collection Of New Studies Using Existing And Proposed Techniques And Instrumentation For Nondestructive Testing And Analysis Of Concrete Materials And Structures, Shane D. Boone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A variety of studies were performed using existing and newly proposed techniques and instrumentation to further the understanding of nondestructive testing of concrete. A new combined stress wave propagation method was developed that combined the existing methods of the spectral analysis of surface waves, impact echo, and free-free resonant column experimental and analysis techniques. The method was used to determine the stiffness profile and location of embedded voids in a concrete tunnel lining modeled as a three layer concrete slab. A new equation was proposed that predicted the level of damage of concrete samples based on the functions of the …

Surface And Thin Film Analysis Of Microelectronics Materials, Harland G. Tompkins

Scanning Microscopy

The use of probing techniques in the analysis of microelectronics materials is discussed in general and several examples are presented to illustrate the use of these techniques. The emphasis of this paper is for using electrons as the probing particles and both electrons and x-rays as the analyzed particles to deal with analysis of microelectronics materials. The first example involves the interaction of titanium and silicon dioxide. It is shown that when titanium is sputter deposited onto silicon dioxide, the titanium reduces a small amount of the oxide to elemental silicon at the interface. The second example shows how a …

Stabilization Studies On Soil-Cement Mixtures For Experimental Lining--Logan Experimental Section--Logan, Utah, United States Department Of The Interior, Bureau Of Reclamation

Elusive Documents

Earth Materials Laboratory Report No. EM-170 covers the laboratory tests made on one type of soil from Logan, Utah, for the purpose of using the soil in soil-cement canal lining experiments. The intention was that two types of soil would be used for experimental linings at Logan, Utah; a fine sandy soil, poorly graded with little or no silt (Classification Symbol SP) and a fine sandy soil with excess silt (Classification Symbol SF-silty). These field test sections which will provide durability and permeability information gathered under natural conditions were carried out as part of a joint lower-cost canal lining experiment …