Engineering Science and Materials Commons^™

The Influence Of Heat And Mass Transfer On The Setting Rate Of Adhesives Between Porous Substrates, Mubarak Mohammed Khlewee

Electronic Theses and Dissertations

The dynamic penetration of fluid into a porous media where other changes are occurring such as temperature or concentration is of interest to a number of situations. However, little experimental and theoretical analysis of this situation is found in the literature where most of the previously published works have studied the penetration with constant physical properties, where there is no change of the fluid as it enters the pores. This situation is important in the setting of adhesives in porous medium such as in the setting of hot melt and water-based adhesives in the production of paper based packaging. The …

Thermal Stability Of Platinum-Silicon Alloy Films Grown On Langasite Substrates For Use In Microwave Acoustic Sensor Technology, Kell Fremouw

Honors College

Wireless sensors that can operate in temperatures up to 1000°C are widely needed for real time monitoring of large-scale industrial processes. Such sensors will improve efficiency and prevent component failure. Under previous work at UMaine, Surface Acoustic Wave Resonator (SAWR) sensors fabricated on piezoelectric langasite (La₃Ga₅SiO₁₄) wafers have shown promise for wireless strain measurements at high temperatures. However, there is a major technical challenge in attaching SAWR langasite based sensors to metal parts because the large differences in the coefficient of thermal expansion (CTE) between langasite and metals leads to large thermal stresses and …

Technology & Tradition: Shaping Indigenous Collections For The Future, Gretchen Faulkner, Harold Jacobs, Alex Cole, Jonathan Roy, Reed Hayden, Anna Martin, Duane Shimmel

Technical Publications

The Hudson Museum received a UMAI seed grant to support
a collaboration with the Advanced Structures and Composites
Center and Intermedia Programs to replicate a culturally -
sensitive object in our collection. This is a technical publication to describe the process of replicating a Tlingit Frog Clan Helmet (HM5040) requested for repatriation by the Central Council of Tlingit and Haida Indian Tribes of Alaska (CCTHITA).

Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock

Electronic Theses and Dissertations

This work focuses on evaluating different modeling approaches and model parameters for thermoplastic AM, with the goal of informing more efficient and effective modeling approaches. First, different modeling approaches were tested and compared to experiments. From this it was found that all three of the modeling approaches provide comparable results and provide similar results to experiments. Then one of the modeling approaches was tested on large scale geometries, and it was found that the model results matched experiments closely. Then the effect of different material properties was evaluated, this was done by performing a fractional factorial design of experiments where …

The Performance Assessment Of A Small Lighter-Than-Air Vehicle For Earth Science Remote Sensing Missions, Maxwell F. Burtis

Honors College

This summer, a lighter-than-air (LTA) drone was tested in Alaska to measure glacier bedrock fracture density and orientation. Five flights were made in low wind conditions, and the directional stability of the airship made it too challenging to control in flight to realistically acquire useful image sets. The directional stability of the airship, when compared to an actively stabilized consumer-grade quadcopter was inferior. Flight logs and GPS data from the GPS on the LTA drone were analyzed and a quantitative assessment of the observed instability was made. The yaw axis and pitch were analyzed, and the yaw axis instability was …

Development And Experimental Assessment Of Friction-Type Shear Connectors For Frp Bridge Girders With Composite Concrete Decks, William G. Davids, Dante Guzzi, Andrew Philip Schanck

Civil Engineering Faculty Scholarship

This paper details the development and experimental assessment of a friction-type connector, designed to transfer shear flow between the top flange of a fiber-reinforced polymer (FRP) tub girder and a composite concrete deck for bridge applications. In contrast with previously used bearing-type connectors, this system relies on a deformed FRP surface to transfer shear via direct interlock with the concrete deck. The connector is materially efficient, simple to fabricate, can be used with lower-grade structural or stainless-steel fasteners, and provides a high degree of interface stiffness. Six compression-shear specimens were tested to assess the connector fatigue resistance and ultimate connection …

Impact Resistance Of Fiber-Reinforced Composites Using Computational Simulations, Maitham Alabbad

Electronic Theses and Dissertations

Composite materials are widely used in aerospace, automotive and wind power industries due to their high strength-to-weight and stiffness-to-weight ratios and their improved mechanical properties compared to metals. The damage resistance of composite materials due to low velocity impact depends on fiber breakage, matrix cracking and delamination between the interfaces. In this research, a numerical investigation of low velocity impact response of a multidirectional symmetric carbon-epoxy composite laminate is carried out and presented. Two different finite element models are developed for composite laminates made of non-crimp fabric to investigate their behavior under different levels of impact energy. In the first …

Cellulose Nanofibrils (Cnf) For Textile Applications: Production Of Neat Cnf Filaments And Reinforcement Of Natural Fiber Yarns, Shokoofeh Ghasemi

Electronic Theses and Dissertations

Being the most abundant natural polymer on earth, cellulose materials have been used in many different applications. Cellulose nanofibrils (CNF) are a relatively new group of lignocellulose resource-based nanomaterials and have been the topic of many research efforts in wood products and material science field over the recent years. Using CNF in textile applications is one way to diversify product portfolio of these materials as they contain nanoscale fibrils with high mechanical properties which can fulfil textile industry’s demand for strong natural fibers. Considering that CNF is a wood-based cellulosic material in the form of water suspension, in order to …

Parameters That Influence The Performance Of Dispersion Barrier Coatings, Randy Raditya

Electronic Theses and Dissertations

Barrier coating layers are important in many paper grades used in food packaging and have the potential to help reduce our use of plastics in some situations. Barrier layers to produce water proof packaging such as milk or juice cartons or coffee cups are common. Water based dispersion barrier coatings have the potential to be a low-cost alternative to extrusion coated layers. Water borne coatings are reported to be easy to recycle and break down in the environment. However, barrier properties are often less than what is desired and expected for these water borne coatings. The reason for this poor …

Coating Component Migration In Paper Coatings, Emilia Purington

Electronic Theses and Dissertations

In many applications such as in paints and coatings, pigments are mixed with polymeric binders to generate the final product. In the coating of paper, properties like strength, durability, and print quality are affected not only by the binder type, but the final location of the binder relative to the pigments and the fibers. During the application and drying of a paper coating, binder is known to migrate. A number of methods are available to measure the migration of latex or starch. However, all of these methods have some limitations, especially when starch, latex and kaolin are components of the …

Metal Thin Film Stiffness Extraction Technique For Surface Acoustic Wave Filters, Travis R. Weismeyer

Electronic Theses and Dissertations

Accurate knowledge of the surface acoustic wave (SAW) properties propagating at the surface of a piezoelectric substrate with thin films, electrodes or temperature compensated films, is critical in SAW filter design to meet the target frequency response, power durability and performance prior to device fabrication. While reliable material constants exist for substrates such as LiNbO3 used in SAW filters, the absolute elastic constants associated with operational thin films used for electrodes or temperature compensation do not exist. Although the bulk values of the constituent materials are known, the composite film/substrate properties are difficult to predict since they depend strongly on …

Microwave Acoustic Saw Resonators For Stable High-Temperature Harsh-Environment Static And Dynamic Strain Sensing Applications, Anin K. Maskay

Electronic Theses and Dissertations

High-temperature, harsh-environment static and dynamic strain sensors are needed for industrial process monitoring and control, fault detection, structural health monitoring in power plant environments, steel and refractory material manufacturing, aerospace, and defense applications. Sensor operation in the aforementioned extreme environments require robust devices capable of sustaining the targeted high temperatures, while maintaining a stable sensor response. Current technologies face challenges regarding device or system size, complexity, operational temperature, or stability.

Surface acoustic wave (SAW) sensor technology using high temperature capable piezoelectric substrates and thin film technology has favorable properties such as robustness; miniature size; capability of mass production; reduced installation …

Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook

Electronic Theses and Dissertations

This dissertation is concerned with the development of robust numerical solution procedures for the generalized micromechanical analysis of linear and nonlinear constitutive behavior in heterogeneous materials. Although the methods developed are applicable in many engineering, geological, and materials science fields, three main areas are explored in this work. First, a numerical methodology is presented for the thermomechanical analysis of heterogeneous materials with a special focus on real polycrystalline microstructures obtained using electron backscatter diffraction techniques. Asymptotic expansion homogenization and finite element analysis are employed for micromechanical analysis of polycrystalline materials. Effective thermoelastic properties of polycrystalline materials are determined and compared …

Collaborative Research: Mechanics Of Growing Bodies: A Riemannian Geometric Approach, Alireza Shamsaei Sarvestani

University of Maine Office of Research Administration: Grant Reports

The research objective of this grant is to elucidate a differential/Riemannian geometric formulation for the mechanics of growing bodies. The proposed work is based on the concept of a changing material manifold whose dynamics predicts the evolution of the relaxed state of a material body. This theory is applicable to biological tissues in which growth and remodeling are coupled with large deformations. To achieve the research objective of this proposal, a theory of continuum mechanics based on a dynamic material manifold is introduced that couples the growth/remodeling of biological tissues with their large deformations. The proposed research will put growth …

Acquisition Of A Sub-Micron Resolution X-Ray Computed Tomography System, Eric N. Landis, Andre Khalil

University of Maine Office of Research Administration: Grant Reports

The award will be used to purchase a laboratory scale x-ray computed tomography system capable of sub-micron spatial resolution. The system is capable of imaging the internal structure of a wide range of materials. This capability will initially be exploited to answer questions regarding the uptake of trace metals in the environment, bone mineral density, defects in micromachines, membrane and filter processes, artery roughness and fluid flow, and microstructure-property relationships for a variety of heterogeneous and functionally graded materials. All these fields will be aided by the parallel adaptation and implementation of sophisticated 3D image analysis routines to maximize the …

Creel Census And Fisheries Utilization Study, Dickey-Lincoln School Lakes Project, Maine : For The Period 26 May 1976 To 15 August 1976, Final Report To U.S. Army Corps Of Engineers, Gordon W. Russell, Richard W. Hatch, Mary J. Hosmer

Dickey-Lincoln School Lakes Project

To describe the utilization of the existing fishery resource within the project area during the summer of 1976. Information collected between Memorial Day and August 15, 1976 is used to estimate angler use of the area, total catch and economic value of angler use and to profile the user group.