Review Of Γ’ Rafting Behavior In Nickel-Based Superalloys: Crystal Plasticity And Phase-Field Simulation,
2020
Northwestern Polytechnical University, China
Review Of Γ’ Rafting Behavior In Nickel-Based Superalloys: Crystal Plasticity And Phase-Field Simulation, Zhiyuan Yu, Xinmei Wang, Fuqian Yang, Zhufeng Yue, James C. M. Li
Chemical and Materials Engineering Faculty Publications
Rafting is an important phenomenon of the microstructure evolution in nickel-based single crystal superalloys at elevated temperature. Understanding the rafting mechanism and its effect on the microstructure evolution is of great importance in determining the structural stability and applications of the single crystal superalloys. Phase-field method, which is an excellent tool to analyze the microstructure evolution at mesoscale, has been gradually used to investigate the rafting behavior. In this work, we review the crystal plasticity theory and phase-field method and discuss the application of the crystal plasticity theory and phase-field method in the analysis of the creep deformation and microstructure …
Water Conservation Potential Of Self-Funded Foam-Based Flexible Surface-Mounted Floatovoltaics,
2020
Michigan Technological University
Water Conservation Potential Of Self-Funded Foam-Based Flexible Surface-Mounted Floatovoltaics, Kaomi Soulemane Hayibo, Pierce Mayville, Ravneet Kaur Kailey
Michigan Tech Publications, Part 1
A potential solution to the coupled water–energy–food challenges in land use is the concept of floating photovoltaics or floatovoltaics (FPV). In this study, a new approach to FPV is investigated using a flexible crystalline silicon-based photovoltaic (PV) module backed with foam, which is less expensive than conventional pontoon-based FPV. This novel form of FPV is tested experimentally for operating temperature and performance and is analyzed for water-savings using an evaporation calculation adapted from the Penman–Monteith model. The results show that the foam-backed FPV had a lower operating temperature than conventional pontoon-based FPV, and thus a 3.5% higher energy output per …
A First Investigation Of Agriculture Sector Perspectives On The Opportunities And Barriers For Agrivoltaics,
2020
Michigan Technological University
A First Investigation Of Agriculture Sector Perspectives On The Opportunities And Barriers For Agrivoltaics, Alexis Pascaris, Chelsea Schelly, Joshua M. Pearce
Michigan Tech Publications, Part 1
Agrivoltaic systems are a strategic and innovative approach to combine solar photovoltaic (PV)-based renewable energy generation with agricultural production. Recognizing the fundamental importance of farmer adoption in the successful diffusion of the agrivoltaic innovation, this study investigates agriculture sector experts’ perceptions on the opportunities and barriers to dual land-use systems. Using in-depth, semistructured interviews, this study conducts a first study to identify challenges to farmer adoption of agrivoltaics and address them by responding to societal concerns. Results indicate that participants see potential benefits for themselves in combined solar and agriculture technology. The identified barriers to adoption of agrivoltaics, however, include: …
Aerosol Jet Printed Capacitive Strain Gauge For Soft Structural Materials,
2020
Boise State University
Aerosol Jet Printed Capacitive Strain Gauge For Soft Structural Materials, Kiyo T. Fujimoto, Jennifer K. Watkins, Timothy Phero, Takoda Bingham, Kshama Lakshmi Ranganatha, Benjamin C. Johnson, Zhangxian Deng, Brian Jaques, David Estrada
Materials Science and Engineering Faculty Publications and Presentations
Soft structural textiles, or softgoods, are used within the space industry for inflatable habitats, parachutes and decelerator systems. Evaluating the safety and structural integrity of these systems occurs through structural health monitoring systems (SHM), which integrate non-invasive/non-destructive testing methods to detect, diagnose, and locate damage. Strain/load monitoring of these systems is limited while utilizing traditional strain gauges as these gauges are typically stiff, operate at low temperatures, and fail when subjected to high strain that is a result of high loading classifying them as unsuitable for SHM of soft structural textiles. For this work, a capacitance based strain gauge (CSG) …
Study On Cation Exchange Of A Lead Coordination Polymer Targeting Dynamic Mixed Cation Doped And Mixed-Valent Coordination Polymers,
2020
Universiti Malaya
Study On Cation Exchange Of A Lead Coordination Polymer Targeting Dynamic Mixed Cation Doped And Mixed-Valent Coordination Polymers, Hamisu Aliyu Mohammed
Student Works (2020-2029)
Solid solution in Metal-Organic Coordination Polymers (MOCPs) is an emerging synthetic pathway for modifying chemical compositions and has been expansively investigated. It has been demonstrated to be an important tool for engineering novel functional materials that otherwise have not been synthesized via the conventional technique. Although stable solid material with variable functionalities and intriguing structural motifs could be engineered by judicious selection of multivariate metal centers and multifunctional ligands. However, solid solution featuring mixed valence in MOCP is rare. Motivated by the ability of Pb2+ to adopt range of coordination numbers (CN) and chemical environments (CE), in addition to its …
Machine Learning Augmentation Micro-Sensors For Smart Device Applications,
2020
University of Nebraska-Lincoln
Machine Learning Augmentation Micro-Sensors For Smart Device Applications, Mohammad H. Hasan
Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research
Novel smart technologies such as wearable devices and unconventional robotics have been enabled by advancements in semiconductor technologies, which have miniaturized the sizes of transistors and sensors. These technologies promise great improvements to public health. However, current computational paradigms are ill-suited for use in novel smart technologies as they fail to meet their strict power and size requirements. In this dissertation, we present two bio-inspired colocalized sensing-and-computing schemes performed at the sensor level: continuous-time recurrent neural networks (CTRNNs) and reservoir computers (RCs). These schemes arise from the nonlinear dynamics of micro-electro-mechanical systems (MEMS), which facilitates computing, and the inherent ability …
Radiation Modified Chitosan/Polyvinyl Alcohol Film With Polyvinyl Pyrrolidone Coating For Heavy Metal Ion Removal,
2020
Universiti Malaya
Radiation Modified Chitosan/Polyvinyl Alcohol Film With Polyvinyl Pyrrolidone Coating For Heavy Metal Ion Removal, Norhashidah Talip
Student Works (2020-2029)
Chitosan (CS) / Polyvinyl Alcohol (PVA) films were obtained by solution casting method. To be used in the water treatment application, these film need to be improved in mechanical strength. In this study, 2% (w/v) chitosan and 5% (w/v) PVA were blend at different CS: PVA weight ratios (50:50, 70:30 and 90:10). These mixtures were then transformed into films by solution casting method. Mechanical properties of the films were evaluated using tensile strength test where, at 70:30 of CS: PVA ratio gave the best tensile strength. Therefore, this composition was selected to proceed with the radiation modification with Polyvinyl Pyrrolidone …
Examination Of Early Stage Grey Iron Solidification Through The Development Of Fast-Quench Methodology,
2020
Georgia Southern University
Examination Of Early Stage Grey Iron Solidification Through The Development Of Fast-Quench Methodology, James C. Liggett
Honors College Theses
As grey iron casting accounts for a significant share of the foundry industry, proper understanding of the effects of solidification and growth mechanisms on the mechanical properties of grey iron is crucial. Prior experimentation has been performed examining early stage solidification and growth of the carbon phase of ductile iron, in which rapid quench samples are obtained which detail austenite-graphite interactions during solidification. This prior experimentation is built upon in though this research and applied to examine the early stage growth of flake graphite in grey iron. The purpose of this research is to validate a proposed fast-quench method by …
Laser Powder Bed Fusion Of Nitihf High-Temperature Shape Memory Alloy: Effect Of Process Parameters On The Thermomechanical Behavior,
2020
University of Toledo
Laser Powder Bed Fusion Of Nitihf High-Temperature Shape Memory Alloy: Effect Of Process Parameters On The Thermomechanical Behavior, Mohammadreza Nematollahi, Guher P. Toker, Keyvan Safaei, Alejandro Hinojos, S. Ehsan Saghaian, Othmane Benafan, Michael J. Mills, Haluk E. Karaca, Mohammad Elahinia
Mechanical Engineering Faculty Publications
Laser powder bed fusion has been widely investigated for shape memory alloys, primarily NiTi alloys, with the goal of tailoring microstructures and producing complex geometries. However, processing high temperature shape memory alloys (HTSMAs) remains unknown. In our previous study, we showed that it is possible to manufacture NiTiHf HTSMA, as one of the most viable alloys in the aerospace industry, using SLM and investigated the effect of parameters on defect formation. The current study elucidates the effect of process parameters (PPs) on the functionality of this alloy. Shape memory properties and the microstructure of additively manufactured Ni-rich NiTiHf alloys were …
Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles,
2020
University of New Mexico
Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles, Deepak Kunwar
Chemistry and Chemical Biology ETDs
Diesel oxidation catalysts deactivate due to Pt sintering, a major problem in automotive industries. To make sure they operate effectively throughout the lifetime of the vehicle, automotive industries are putting an excessive amount of Pt. There is a need to develop a catalyst that serves long term performance with minimal use of Pt. Jones et al.1 demonstrated that ceria traps Pt atoms. His work generated some logical and valid questions such as what is the mechanism for the formation of anomalously large Pt particles? What is the upper limit of Pt metal loading in the form of single atoms …
A Bibliometric Survey On Polymer Composites In Energy Storage Applications,
2020
Symbiosis Institute of Technology (SIT), Symbiosis International (Deemed University) (SIU), Lavale, Pune, India
A Bibliometric Survey On Polymer Composites In Energy Storage Applications, Babaji Ghule, Meena Laad
Library Philosophy and Practice (e-journal)
Ceramic polymer composites have gained a significant place in energy storage applications for electrical capacitors due to their distinguished properties. There is a huge demand of capacitors with high energy density, high dielectric strength, negligibly low dielectric loss, light weight, chemically less reactive in energy storage applications. These requirements can be fulfilled by ceramic polymer composites only which exhibit all the above-mentioned characteristics. Considering the huge demand of such capacitors, it has attracted the attention of researchers around the world. The present work attempts to summarise all the research conducted on Polymer Composites for energy storage applications and provides an …
Desorption From Hot Scandate Cathodes: Effects On Vacuum Device Interior Surfaces After Long-Term Operation,
2020
University of Kentucky
Desorption From Hot Scandate Cathodes: Effects On Vacuum Device Interior Surfaces After Long-Term Operation, Mujan N. Seif, Thomas John Balk, Matthew J. Beck
Chemical and Materials Engineering Faculty Publications
Scandate cathodes have exhibited superior emission properties compared to current state-of-the-art “M-type” thermionic cathodes. However, their integration into vacuum devices is limited in part by a lack of knowledge regarding their functional lifespan and behavior during operation. Here, we consider thermal desorption from scandate cathodes by examining the distribution of material deposited on interior surfaces of a sealed vacuum device after ~26,000 h of cathode operation. XPS, EDS, and TEM analyses indicate that on the order of 1 wt.% of the initial impregnate is desorbed during a cathode’s lifetime, Ca does not desorb uniformly with time, and little to no …
Effects Of Laser Power And Substrate On The Raman Shift Of Carbon-Nanotube Papers,
2020
University of Kentucky
Effects Of Laser Power And Substrate On The Raman Shift Of Carbon-Nanotube Papers, Fuqian Yang, Shanshan Wang, Yuling Zhang
Chemical and Materials Engineering Faculty Publications
The progress in the fabrication of carbon-nanotube-based structures has made it possible to use Raman spectroscopy to measure the deformation states of carbon nanotubes and abutting materials. In this work, we investigate the effects of laser power and surrounding materials on the Raman shift of carbon-nanotube (CNT) papers for the laser intensity in a range of 0.071 to 1.415 kW/mm2 without action of mechanical loading. Two different configurations of the CNT papers are used in the Raman measurement; one uses a suspended CNT paper, and the other places a CNT paper on a glass or aluminum substrate. The experimental …
Conversion From Metal Oxide To Mof Thin Films As A Platform Of Chemical Sensing,
2020
University of South Florida
Conversion From Metal Oxide To Mof Thin Films As A Platform Of Chemical Sensing, Meng Chen
USF Tampa Graduate Theses and Dissertations
Chemical sensor is working as a widely used device which can be applied to the detection of specific chemicals that are existing in the environment especially in gas phase. The detection of combustible and toxic chemicals can be extremely important in the field of both industrial and civil activities. The chemical sensor is commonly operating by utilizing a chemical or physical interaction between the specific chemical compound and the sensing functional unit, to obtain an electronic signal caused by the property change and realize the chemical detection. Traditional chemical gas sensors such as catalytic gas sensor, thermal conductivity gas sensor, …
Proximity-Induced Magnetization In Graphene: Towards Efficient Spin Gating,
2020
Institute Ruder Boskovic
Proximity-Induced Magnetization In Graphene: Towards Efficient Spin Gating, Mihovil Bosnar, Ivor Lončarić, P. Lazić, Kirill Belashchenko, Igor Žutić
Kirill Belashchenko Publications
Gate-tunable spin-dependent properties could be induced in graphene at room temperature through the magnetic proximity effect by placing it in contact with a metallic ferromagnet. Because strong chemical bonding with the metallic substrate makes gating ineffective, an intervening passivation layer is needed. Previously considered passivation layers result in a large shift of the Dirac point away from the Fermi level, so that unrealistically large gate fields are required to tune the spin polarization in graphene (Gr). We show that a monolayer of Au or Pt used as the passivation layer between Co and graphene brings the Dirac point closer to …
New Metal Based Saturable Absorber For Ultrashort Pulse Generation,
2020
Universiti Malaya
New Metal Based Saturable Absorber For Ultrashort Pulse Generation, Muhammad Taufiq Ahmad
Student Works (2020-2029)
Cost-efficient, robust and flexible laser systems are vital for a wide-range of applications ranging from high-precision material processing to biomedicine. This thesis aims to explore pure silver and gold based saturable absorbers (SAs) as Q-switcher and mode-locker in various fibre laser cavities. The generations of Q-switched pulses in 1-,1.55-, and 2-micron regions have been successfully demonstrated using a pure gold, which was deposited using electron beam deposition onto a PVA thin-film as SA. For instance, a stable Q-switched thulium-doped fibre laser (TDFL) operating at 1949 nm was successfully demonstrated with the gold SA. The proposed laser generates Q switched pulses …
Tuning Degradation And Cell Adhesion In Next Generation Resorbable Implants,
2020
University of South Florida
Tuning Degradation And Cell Adhesion In Next Generation Resorbable Implants, Ufuomaroghene Ikoba
USF Tampa Graduate Theses and Dissertations
Osteoarthritic and bone degenerative diseases are expected to grow immensely as the aging population, 65 years and older increases. Orthopedic implants are one sub-class of medical devices that are used to treat bone breaks and fractures. Traditionally, internal fixation implants are manufactured using titanium or stainless steel. Magnesium, a bioresorbable and biodegradable material, has been proposed as an alternative to titanium and stainless steel. The goal of this research is to control the degradation behavior of magnesium implants by developing crystallized thin poly(lactic acid) copolymer films as protective coatings. To do this, this work was divided into two aims. Aim …
Urine Volume Reduction During Long-Duration Cave Exploration By A Light-Weight And Portable Forward Osmosis System,
2020
University of Akron
Urine Volume Reduction During Long-Duration Cave Exploration By A Light-Weight And Portable Forward Osmosis System, Sebastian Engelhardt, Katey E. Bender, Jörg Vogel, Stephen E. Duirk, Francisco B. Moore, Hazel A. Barton
International Journal of Speleology
The preservation of caves is a challenge during long-duration cave expeditions where human waste can add significant nitrogen to the cave ecosystem. Since the removal of urine that accumulates during a multi-day caving trip is not always feasible due to weight and volume constraints, a light-weight and portable filtration system that is capable of reducing urine volume would be desirable. In this study we tested the Aquaporin Inside hollow fiber membrane in a forward osmosis (FO) setup to evaluate its capability to reduce urine volume while rejecting nitrogenous compounds using different draw solution chemistries and water recovery rates. As a …
Laser-Induced Modifications In Two-Dimensional Materials,
2020
University of South Florida
Laser-Induced Modifications In Two-Dimensional Materials, Tariq Afaneh
USF Tampa Graduate Theses and Dissertations
Atomically thin two-dimensional (2D) materials have attracted a growing interest in the lastdecade from the fundamental point of view as well as their potential applications in functional devices. Due to their high surface-to-volume ratio, the physical properties of 2D materials are very sensitive to the environmental factor such as surrounding media and illumination conditions (e.g. light-mater interaction). In the first part of this dissertation I will present recent advances in developing laser-assisted methods to tune the physical properties of 2D transition metal dichalcogenides (TMDs). We demonstrate laser-assisted chemical modification ultrathin TMDs, locally replacing selenium by sulfur atoms. The photo-conversion process …
Ensemble Labeling Towards Scientific Information Extraction (Elsie),
2020
DePaul University
Ensemble Labeling Towards Scientific Information Extraction (Elsie), Erin Murphy
College of Computing and Digital Media Dissertations
Extracting scientific facts from unstructured text is difficult due to challenges specific to the ambiguity of the language, the complexity of the scientific named entities and relations to be extracted. This problem is well illustrated through the extraction of polymer names and their properties. Even in the cases where the property is a temperature, identifying the polymer name associated with the temperature may require expertise due to the use of acronyms, synonyms, complicated naming conventions and by the fact that new polymer names are being “introduced” to the vernacular as polymer science advances. While there exist domain-specific machine learning toolkits …
