Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines,
2022
California Polytechnic State University, San Luis Obispo
Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter
Materials Engineering
Polymer concrete is a composite material used to replace cast iron and steel in wafer grinding machines for vibration damping. During the grinding and lapping processes of manufacturing silicon wafers, excessive vibrations may cause subsurface damage which requires additional polishing and reduces yield. Nine compositions containing various levels of granulated rubber and glass fibers were manufactured. CRM WRF-10 granulated rubber was examined at 0%, 5%, and 10% and Corning Cem-Fil glass fibers were added at 0%, 0.5%, and 1% by weight. Smooth-On EpoxAcast 690 epoxy resin was held constant at 16% for each composition. Crushed granite aggregate from Martin Marietta, …
Text Summarization Towards Scientific Information Extraction,
2022
DePaul University
Text Summarization Towards Scientific Information Extraction, Abigail Keller
College of Computing and Digital Media Dissertations
Despite the exponential growth in scientific textual content, research publications are still the primary means for disseminating vital discoveries to experts within their respective fields. These texts are predominantly written for human consumption resulting in two primary challenges; experts cannot efficiently remain well-informed to leverage the latest discoveries, and applications that rely on valuable insights buried in these texts cannot effectively build upon published results. As a result, scientific progress stalls. Automatic Text Summarization (ATS) and Information Extraction (IE) are two essential fields that address this problem. While the two research topics are often studied independently, this work proposes to …
Copolymer Microphase Separation, Properties, And Applications,
2022
The University of Southern Mississippi
Copolymer Microphase Separation, Properties, And Applications, Daniel Weller
Dissertations
Copolymers represent a broad, but critically important class of materials. Often having properties superior to either of its constituents, copolymers are used in virtually all industries including automotive, aerospace, coatings, packaging, and cosmetics. Certain copolymers microphase separate to form nanosized domains that improve the physical properties of the copolymer. The polymer community already has a thorough understanding of how phase separation occurs, but the commercialization of phase separating copolymers lags significantly behind academia. Many of the copolymers that exist that have been undercharacterized and underutilized. This dissertation examines two such polymers. The first, a hard polystyrene material with soft nanodomains. …
Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes,
2022
Technological University Dublin
Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal
Articles
The increased environmental pollution has led to finding sustainable solutions for non-renewable plastic-based food packaging materials. Thus, the use of biomaterial-based packaging material has become an immense trend. This work aims at developing an antimicrobial biodegradable chitosan-alginate bio-nano composite film with TiO2 nanoparticle (NPs) for food packaging applications. The film was developed by a solution casting method. The chemical, mechanical, thermal, barrier, antimicrobial, and biodegradable properties of the packaging films were evaluated. Packaging studies were performed for 15 days for cherry tomatoes. The designed packaging material had enhanced the mechanical properties with a significantly (p < 0.05) higher tensile strength of 15.76 folds and 2 fold higher elongation at break. The UV barrier properties increased by 88.6%, while the film transparency decreased by 87.23%. Molecular interaction of N-H covalent bonds was observed between alginate and chitosan together with TiO2 NPs. The developed bio-nano composite film showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene with a log reduction of 7.08, 7.28, 6.04 & 6.02 log CFU/ml respectively at 24 hours incubation period. The film was completely biodegraded and a weight loss of 89.06% was observed in bio-nanocomposite film during the 3 months. Shelf-life estimation of cherry tomato using developed packaging films showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth when packaged with prepared film. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability, the prepared active bio-nano composite packaging films could be considered a potential candidate for fruit packaging.
Analysis Of Hemp Fiber Reinforced Polylactide Composite Under High Strain-Rate,
2022
University of Mississippi
Analysis Of Hemp Fiber Reinforced Polylactide Composite Under High Strain-Rate, Benjamin Rhoads
Honors Theses
The introduction of hemp fibers into a polylactide (PLA) matrix creates a hemp fiber-reinforced composite with 10% hemp fibers and 90% PLA. Natural fibers are becoming a popular alternative to synthetic fibers since they are environmentally friendly, and hemp-fibers are becoming used more often as the demand for natural fibers increased. A Split-Hopkinson Pressure Bar was used to test this composite against a control group using elastic wave propagation theory. Strain gauges were mounted on the incident and transmission bars of the SHPB to measure the propagation of the wave that caused the strain in the sample, which were used …
Synthesis Of Aromatic Acetylene Alcohols Based On Benzaldehyde And Its Halogenated Products,
2022
Chirchik State Pedagogical Institute, Chirchik, Uzbekistan
Synthesis Of Aromatic Acetylene Alcohols Based On Benzaldehyde And Its Halogenated Products, Sanat Samatov, Abduvakhab Ikramov, Saida Abdurakhmanova, Odiljon Ziyadullayev, Guzal Otamukhamedova
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of this study is to synthesize the corresponding aromatic acetylenic alcohols by alkylation with phenylacetylene in a complex catalytic system based on Zn(OTf)2 and TBAF·3H2O for the first time with benzaldehyde and some of its halogen derivatives. The selectivity and stability of catalysts used for the yields of reactions for the synthesis of aromatic acetylene alcohols were analyzed. The effect of benzaldehyde and its halogenated derivatives on the product yield was analyzed. The nature, structure, isomerism, spatial structure and other properties influenced to this reactions were studied. Some features of reactions of synthesis of aromatic …
Study Of Sorption Of Some Metal Ions By The Obtained Phosphoric Acid Cation Exchanger Of Polycondensation Type,
2022
Tashkent Chemical Technological Institute, Tashkent, Uzbekistan
Study Of Sorption Of Some Metal Ions By The Obtained Phosphoric Acid Cation Exchanger Of Polycondensation Type, Malika Berdieva, Rano Nazirova, Alisher Yuldashev, Umida Sharipova, Dilmurod Azimov
CHEMISTRY AND CHEMICAL ENGINEERING
The purpose of this work is to investigate the sorption of Cu2+, Co2+, Ni2+, UO22+ ions, etc. depending on the ionic form of the cationite and the pH of the medium on phosphoric acid cationite obtained by forsforylation of a polymer based on cubic waste of the Shurtan gas-chemical complex and a secondary product of the hydrolysis industry – furfural. It was found that copper and UO22+ ions are best sorbed by cationite when the cationite is in Na form. The UO22+ ion is sorbed fairly well in …
Thermal Properties Of Polyelectrolyte Complexes Of Bombyx Mori Chitosan With Collagen,
2022
Institute of Chemistry and Physics of Polymers, Tashkent, Uzbekistan
Thermal Properties Of Polyelectrolyte Complexes Of Bombyx Mori Chitosan With Collagen, Shuhrat Khudoyberdiev, Noira Vokhidova, Mukhitdin Abdurazakov, Sayora Rashidova
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the work was to study the thermal behavior of the polyelectrolyte complexes of Bombyx mori ChS with collagen. As a result of the studies, the thermal properties of polyelectrolyte complexes based on Bombyx mori chitosan with collagen in wt. rel. 1:0,1 and 1:0,2 respectively. It has been determined that the most significant weight changes for chitosan with a molecular weight of 15×103 and the degree of deacetylation of 85% occur at a temperature is 270 °C, when the mass loss rate reaches its maximum value. For collagen, the same temperature is 277 °C. For complexes ChS/collagen …
Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics,
2022
University of Maine
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 …
Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors [Us Patent Us11320596b2],
2022
Air Force Institute of Technology
Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors [Us Patent Us11320596b2], Jeremiah C. Williams, Hengky Chandrahalim
Faculty Publications
A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of the optical fighter using a two-photon polymerization process on a photosensitive polymer by a three-dimensional micromachining device. The three-dimensional microscopic optical structure having a hinged optical layer pivotally connected to a distal portion of a suspended structure. A reflective layer is deposited on a mirror surface of the hinged optical layer while in an open position. The hinged optical layer is subsequently positioned in the closed position to align the mirror surface to at least partially reflect a light signal back …
Synthesis Of Monodisperse Nanoscintillators At High Temperatures For Biomedical Relevant Applications,
2022
Clemson University
Synthesis Of Monodisperse Nanoscintillators At High Temperatures For Biomedical Relevant Applications, Eric Zhang
All Dissertations
Luminescent sub-100 nm particulates continuously generate immense research interest in the biomedical field for imaging, theranostics, and optogenetics. Conventionally, upconversion nanoparticles or UV activated semiconductors are studied, however these materials are limited by biological barriers such as the skin which reduces the penetration depth of these excitation sources, tissue's auto- fluorescence, and toxicity. One approach to overcome these challenges is to use nanoscintillators (sub-100 nm materials that can generate visible light using high energy excitation sources such as x-rays) which can generate light locally to the human body. Numerous scintillators have been reported since the discovery of x-rays from the …
Additive Manufacturing Of Variable Contrast Computed Tomography Anatomical Phantoms Using A Single Feedstock In Fused Filament Fabrication,
2022
University of New Orleans
Additive Manufacturing Of Variable Contrast Computed Tomography Anatomical Phantoms Using A Single Feedstock In Fused Filament Fabrication, Cory J. Darling
University of New Orleans Theses and Dissertations
Anatomical phantoms used in biomedical education and training benefit greatly from Fused filament fabrication’s (FFF) ability to rapidly produce complex and unique models. Current materials and methods used in FFF have limited ability to accurately produce phantoms that can mimic the radiological properties of multiple biological tissues. This research demonstrates that the CT contrast of FFF produced models can be modified by varying the concentration of bismuth oxide in acrylonitrile butadiene styrene (ABS) filaments and a tunable CT contrast that mimics the CT contrast ranging from fatty tissue to cortical bone using a single composite filament without introducing artificial image …
Isolation And Production Of Tandem Collagen Binding Domain From Clostridial Collagenase Colg And Developments In C1q Reagent Production For Future Molecule Characterization Work,
2022
University of Arkansas, Fayetteville
Isolation And Production Of Tandem Collagen Binding Domain From Clostridial Collagenase Colg And Developments In C1q Reagent Production For Future Molecule Characterization Work, Stephanie Beitle
Chemical Engineering Undergraduate Honors Theses
This thesis covers a two part project: the production methods to create a double collagen binding domain molecule with a growth factor for wound healing applications and the development of a new in-house production method for isolating C1q from bovine blood. The wound healing molecule was created using transformation, sonication, and purification before being tested via electrophoresis SDS page and Western blots to confirm the molecule’s presence. The C1q in-house production method utilizes an ultrafiltration flow cell rather than dialysis at a critical point in the process, allowing for researchers to not only be able to use a single small …
Effects Of Sizing Agents On Mechanical Properties Of Carbon Fiber–Polymer Composites Via Fused Filament Fabrication Additive Manufacturing.,
2022
University of Louisville
Effects Of Sizing Agents On Mechanical Properties Of Carbon Fiber–Polymer Composites Via Fused Filament Fabrication Additive Manufacturing., Benjamin D. Mitchell
Electronic Theses and Dissertations
This study demonstrated the effects of changing the sizing agent parameter during the preparation of carbon fibers on the mechanical properties of composite made with acrylonitrile butadiene styrene (ABS) as the matrix material and carbon fibers as the fiber material. Three types of sizing agents produced by Allnex were used to coat three different batches of carbon fibers that were mixed with a torque rheometer and extruded with a barrel-style melt extruder into continuous spools of 1.75 mm filament for use with commercial 3D printers. Tensile tests were conducted on the filaments and tensile bars printed from the materials. Results …
Sustainable Composites From Agricultural And Petroleum Waste,
2022
Clemson University
Sustainable Composites From Agricultural And Petroleum Waste, Menisha S. Karunarathna
All Dissertations
Green gas emission has been a pervasive and persistent subject of debate for a prolonged period. The soaring number of industries and vehicle fuel emissions presage a concomitant rise in global CO2 emissions. Global cement production is responsible for 8% of the total CO2 release, yet, the production continues due to the surging demand. Hence, there is an ongoing quest to find alternatives for cement and building materials produced with zero to lower CO2 emissions. The work presented in this dissertation focuses on finding recyclable, zero CO2 gas-producing high sulfur biocomposites materials, which can compete with …
Extractive Membranes For The Detection And Screening Of Waterborne Plutonium,
2022
Clemson University
Extractive Membranes For The Detection And Screening Of Waterborne Plutonium, James Foster
All Dissertations
The development of rapid screening tools for special nuclear materials remains a crucial focus for nonproliferation efforts. Traditional approaches for the analysis of trace-level Pu isotopes in water requires tedious and time-consuming sample preparation steps that do not lend well to expeditious screening. Therefore, a novel analytical method that combines both Pu concentration and source preparation into a single detection system would make for an invaluable tool for nuclear security applications. Extractive membranes absorbers can help to fulfill this role as they are capable of concentrating Pu to detectable limits while subsequently serving as alpha spectrometry sample sources. In Chapter …
Insect Antennae As Bioinspirational Superstrong Fiber-Based Microfluidics,
2022
Clemson University
Insect Antennae As Bioinspirational Superstrong Fiber-Based Microfluidics, Griffin J. Donley
All Theses
Nature is frequently turned to for inspiration for the creation of new materials. Insect antennae are hollow, blood-filled fibers with complex shape, and are cantilevered at the head. The antenna is muscle-free, but the insect can controllably flex, twist, and maneuver it laterally. To explain this behavior, a comparative study of structural and tensile properties of the antennae of Periplaneta americana (American cockroach), Manduca sexta (Carolina hawkmoth), and Vanessa cardui (painted lady butterfly) was performed. These antennae demonstrate a range of distinguishable tensile properties, responding either as brittle fibers (Manduca sexta) or strain-adaptive fibers that stiffen when stretched (Vanessa cardui …
Mechanochromic Tunable Emissions Of Hydrogel Encapsulated Radioluminescent Crystalline Colloidal Arrays,
2022
Clemson University
Mechanochromic Tunable Emissions Of Hydrogel Encapsulated Radioluminescent Crystalline Colloidal Arrays, Sarah Mell
All Theses
Crystalline colloidal arrays (CCAs) are periodic dielectric arrays composed of monodisperse, negatively charged nanoparticles with unique optical characteristics. Poly(styrene-co-propargyl acrylate) (PS-PA) based copolymer nanoparticles synthesized via an emulsion polymerization form the basis of the CCAs in this work. The negatively charged surfaces result in the colloidal nanoparticles self-assembling into a face-centered cubic (fcc) crystal-like structure. The long-range order and spatial periodicity of the array result in a rejection wavelength, characteristic of CCAs, in which a specific wavelength of light is forbidden from propagating throughout the optical system. The CCAs exhibit mechanochromism through a rejection wavelength shift corresponding to a change …
Simplified Synthesis Of Conjugated Polymers Enabled Via 1,4-Dihydropyrrolo[3,2-B]Pyrrole,
2022
Kennesaw Sate University
Simplified Synthesis Of Conjugated Polymers Enabled Via 1,4-Dihydropyrrolo[3,2-B]Pyrrole, Kenneth-John Jack Bell
Master of Science in Chemical Sciences Theses
Conjugated polymers have attracted significant attention as the active layer material in organic electronics, such as organic photovoltaics and light-emitting diodes, partly due to the ability to influence a broad range of properties through structural design motifs. However, high performance conjugated polymers suffer from numerous synthetic steps, generation of toxic waste, and harsh reaction conditions all of which impart additional costs that inhibit their widespread utilization. Therefore, an emphasis on reducing synthetic complexity and utilizing abundant, commercially available starting materials is needed for organic electronics to reach their full potential. Dihydropyrrolo[3,2-b]pyrrole (H2DPP) chromophores offer a simple one-pot synthesis …
Detection Of Trace Heavy Metals In Water: Development Of Electrochemical Sensors,
2022
Kennesaw State University
Detection Of Trace Heavy Metals In Water: Development Of Electrochemical Sensors, Quang Lam, Joel Mututeke
Symposium of Student Scholars
The presence of heavy metals in our ecosystem poses significant ecological and physiological consequences. As a result, numerous techniques are developed for the detection of contaminants in aqueous solutions. However, early and trace detection of such contaminants still remains a challenge. Amongst many techniques, electrochemistry driven sensors have shown promise due to their possibility of miniaturization and low-cost. Our research investigates the use of electrically conducting polymer and atomically thin carbon materials as electrodes towards the development of electrochemical sensor. Nanocomposite electrode films have been synthesized and fabricated using in-situ polymerization technique and the relationship between number of cycles of …
