Open Access. Powered by Scholars. Published by Universities.®
- Institution
Articles 1 - 7 of 7
Full-Text Articles in Entire DC Network
Advances In Cellulose Nanomaterial-Based Foams For Environmental Applications, Md Musfiqur Rahman
Advances In Cellulose Nanomaterial-Based Foams For Environmental Applications, Md Musfiqur Rahman
Electronic Theses and Dissertations
The use of metal-oxide nanoparticles adsorbents is limited to fixed-bed columns in industrial-scale water treatment applications. This limitation is commonly attributed to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials, or a lack of adsorption capacity. Foams and aerogels derived from cellulose nanomaterials have unique characteristics, such as high porosity and low density, which enables their use in a variety of environmental applications, including water treatment. However, the overall use of cellulose nanomaterial-based foams in various environmental sectors is limited due to the high cost of production associated with time- and …
Feasibility Of Thermoplastic Extrusion Welding As A Joining Method For Vacuum-Assisted Additively Manufactured Tooling, Chase C. Flaherty
Feasibility Of Thermoplastic Extrusion Welding As A Joining Method For Vacuum-Assisted Additively Manufactured Tooling, Chase C. Flaherty
Electronic Theses and Dissertations
In recent years, additive manufacturing (AM) has been successfully utilized for the production of large-scale composite tooling. Within these endeavors, however, limited research has focused on joining methods between printed sections. This work evaluates the feasibility of thermoplastic extrusion welding as a joining method for additively manufactured tooling structures. This joining method was assessed based on industry specifications of conventional thermoset tooling for wind blade manufacturing utilizing the vacuum-assisted resin transfer molding (VARTM) process. The specifications include requirements for the mechanical strength, vacuum integrity, roughness, and hardness of the tool surface. The feasibility of this welded polymer joint was demonstrated …
Thermoplastics 3d Printing Using Fused Deposition Modeling On Fabrics, Maxwell M. Blais
Thermoplastics 3d Printing Using Fused Deposition Modeling On Fabrics, Maxwell M. Blais
Electronic Theses and Dissertations
The creation of objects with integrated flexibility is desired and this can be achieved by additive manufacturing on fabric. We propose to use a textile fabric as a flexible joint and create to create an entire object with smaller parts called segments. Such a novel technique will bring integrated flexibility and folded assemblies using extrusion based additive manufacturing machines. The proposed process allows segments to be created flat one at a time on a continuous fabric, which will be suitable for flat to folded assemblies and eliminate size limitations of the 3D printer. Techniques considering object segmentation were used to …
Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock
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 …
Characterization Of Directed Energy Deposition Additively Manufactured Grcop-42 Alloy, Scott Landes
Characterization Of Directed Energy Deposition Additively Manufactured Grcop-42 Alloy, Scott Landes
Electronic Theses and Dissertations
GRCop is an alloy family constructed of copper, chromium, and niobium and was developed by NASA for high heat flux applications. The first of its kind, GRCop-84, was specifically designed for the environments seen by channel cooled main combustion chamber liners. To further increase thermal conductivity while maintaining material strength characteristics, the percentage of alloying elements were cut in half and GRCop- 42 was developed. In recent years, NASA has successfully additively manufactured GRCop with comparable material characteristics to wrought GRCop using a Laser Powder Bed Fusion (L-PBF) process. Benefits of this process include fabrication of intricate cooling channels as …
Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer
Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer
Electronic Theses and Dissertations
This thesis is an examination of two material systems derived from polylactic acid (PLA) and polyethylene glycol (PEG). PLA is a polymer commonly sourced from renewable sources such as starches and sugars. It is a relatively strong, biodegradable polymer, making it ideal for use in the body. Even though it has a relative high strength, PLA is also brittle leading to the use of plasticizers to increase flexibility. One such plasticizer is PEG, which is a material that can exist at room temperature as either a thin liquid, or a hard waxy solid depending on the molecular weight. The first …
Development Of Material For 3d Printed Habitats With Extraplanetary Applications, Taylor Wait
Development Of Material For 3d Printed Habitats With Extraplanetary Applications, Taylor Wait
Electronic Theses and Dissertations
3D printing, also called Additive Manufacturing, has increasingly become a focus for research because of the potential to replace complicated assemblies or complex parts with a single printed item. The space industry is very interesting in studying 3d printing with parts being tested and used on rockets, a 3D printer being installed at the International Space Station and is being developed for use in manned exploration of extraplanetary bodies to build habitats. To encourage teams from around the world to develop technologies and materials for autonomous habitat construction using minimal Earth exports, NASA created the 3D Printed Habitat Challenge. NASA …