Microstructure And Microchemistry Of Laser Welds Of Irradiated Austenitic Steels, 2021 Boise State University
Microstructure And Microchemistry Of Laser Welds Of Irradiated Austenitic Steels, Yaqiao Wu, Megha Dubey
Materials Science and Engineering Faculty Publications and Presentations
This article investigates the integrity of laser welds on neutron irradiated, He-containing steels. Life extension of the current fleet of light water reactors could necessitate repair of cracks on irreplaceable internal components, but heat input of weld repairs exacerbates the problem by initiating He-induced cracking. Laser welding is a promising low-heat-input technology thought to limit the extent of He-induced cracking. In this study, we produce laser welds in a hot cell on AISI 304L stainless steel plates previously irradiated in the Experimental Breeder Reactor (EBR)-II. We select a systematic set of three specimens spanning fluences ~1–28 displacements per ...
Advanced Research And Development Of Face Masks And Respirators Pre And Post The Coronavirus Disease 2019 (Covid-19) Pandemic: A Critical Review, Ebuka A. Ogbuoji, Amr M. Zaky, Isabel C. Escobar
Chemical and Materials Engineering Faculty Publications
The outbreak of the COVID-19 pandemic, in 2020, has accelerated the need for personal protective equipment (PPE) masks as one of the methods to reduce and/or eliminate transmission of the coronavirus across communities. Despite the availability of different coronavirus vaccines, it is still recommended by the Center of Disease Control and Prevention (CDC), World Health Organization (WHO), and local authorities to apply public safety measures including maintaining social distancing and wearing face masks. This includes individuals who have been fully vaccinated. Remarkable increase in scientific studies, along with manufacturing-related research and development investigations, have been performed in an attempt ...
Assessment Of Carbon Dioxide Emission And Its Impact On High-Rise Mixed-Use Buildings In Egypt, 2021 The American University in Cairo AUC
Assessment Of Carbon Dioxide Emission And Its Impact On High-Rise Mixed-Use Buildings In Egypt, Ahmed Salah Hamza
Theses and Dissertations
With Egypt's vision of 2030 focusing on sustainable development with a true emphasis on Carbon Dioxide (CO2) emission reduction in the newly built cities and high-rise buildings, efforts are exerted on various levels towards accomplishing the vision’s goals. This is achieved through multiple tools and models associated with aiding the reduction of carbon emissions, yet not a clear one was introduced for the mixed-use buildings in Egypt.
Through this work, a significant gap was identified with respect to high-rise buildings carbon emission assessment in Egypt. This was a main driving force for this work in an attempt ...
Neural Network Model For Estimation Of The Induced Electric Field During Transcranial Magnetic Stimulation, 2021 Iowa State University
Neural Network Model For Estimation Of The Induced Electric Field During Transcranial Magnetic Stimulation, Oluwaponmile F. Afuwape, Olumide Olafasakin, David C. Jiles
Electrical and Computer Engineering Publications
Transcranial Magnetic Stimulation (TMS) is a non-invasive neuromodulation technique with applications in brain mapping and effective neuronal connectivity. In its repetitive mode, it is used for the treatment of neurological and psychiatric disorders. It functions on the principle of electromagnetic induction, where generated magnetic fields (H-field) induce electric field (E-field) that stimulates the brain’s neurons. With TMS studies, accurate estimation of the induced E-field is usually necessary. However, this requires a lot of processes, including the three-dimensional head model generation from magnetic resonance images (MRI) using the SimNIBS software and finite element analysis to calculate the induced E-field. These ...
Incommensurate Transition-Metal Dichalcogenides Via Mechanochemical Reshuffling Of Binary Precursors, Ihor Hlova, Prashant Singh, Serhiy Z. Malynych, Roman V. Gamernyk, Oleksandr Dolotko, Vitalij K. Pecharsky, Duane D. Johnson, Raymundo Arroyave, Arjun K. Pathak, Viktor P. Balema
Ames Laboratory Accepted Manuscripts
A new family of heterostructured transition-metal dichalcogenides (TMDCs) with incommensurate (“misfit”) spatial arrangements of well-defined layers was prepared from structurally dissimilar single-phase 2H-MoS2 and 1T-HfS2 materials. The experimentally observed heterostructuring is energetically favorable over the formation of homogeneous multi-principle element dichalcogenides observed in related dichalcogenide systems of Mo, W, and Ta. The resulting three-dimensional (3D) heterostructures show semiconducting behavior with an indirect band gap around 1 eV, agreeing with values predicted from density functional theory. Results of this joint experimental and theoretical study open new avenues for generating unexplored metal-dichalcogenide heteroassemblies with incommensurate structures and tunable physical properties.
Solvent Analysis Of Phenolic Resin Glass Fiber Reinforced Prepreg During Out-Time, 2021 California Polytechnic State University, San Luis Obispo
Solvent Analysis Of Phenolic Resin Glass Fiber Reinforced Prepreg During Out-Time, Sixin Zhai, Crystal Ipong
Phenolic resin glass fiber reinforced prepregs are highly suitable for airplane interior components due to their high fire resistance, high temperature performance, and low-density characteristics. Safran Cabin seeks to improve their storage of the phenolic resin prepreg during their manufacturing process. The issues the company faces are the occasional delamination of prepreg laminas or the loss of tackiness rendering the lamina unfit for use. The area of investigation was determining the weight loss of volatiles during out-time. The term “out-time” consists of the time the prepreg experiences in transit, on the shop floor, and in short-term temperature-controlled storage. Simulated storage ...
The Effects Of Glass Fiber Fillers On Epoxy Resin Performance, 2021 California Polytechnic State University, San Luis Obispo
The Effects Of Glass Fiber Fillers On Epoxy Resin Performance, Ashton Robert Reinhold, Manuel Jose Aguirre Ii
Premature failure of filtration members in biochemical processing is a costly issue for manufacturers. This research aims to determine whether or not the premature failure due to thermal fatigue in medical filtration devices can be mitigated by glass fiber addition. The study was conducted to identify the effects of e-glass fiber filler content in an epoxy matrix on the mechanical and thermal properties of the epoxy system. The epoxy was evaluated over a filler content of 0-50wt% in level increments of 12.5wt% and temperatures ranging from ambient to 160°C in increments of 15°C. Cylindrical and tensile bar ...
Metallurgical And Thermal Processing Investigation Of Additively Manufactured Superalloys Jbk-75 And Nasa-Hr-1, 2021 California Polytechnic State University, San Luis Obispo
Metallurgical And Thermal Processing Investigation Of Additively Manufactured Superalloys Jbk-75 And Nasa-Hr-1, Allyse Birken, Derek Noel
Aerojet Rocketdyne is investigating the use of directed energy deposition (DED), an additive manufacturing process, to reduce cost and lead time for manufacturing complex rocket engine components for their RS-25 engines. JBK-75 and NASA-HR-1, two Fe-Ni-base, age-hardenable (γ′) superalloys, are used for nozzle structural jackets and hot gas manifolds. Currently, these parts are produced using traditional forging or casting methods followed by intensive machining operations. Additionally, these alloys were designed for use in the wrought condition and require a different set of post-processing heat treatments when produced using DED due to their dendritic, segregated microstructure in the as-built condition. Homogenization ...
Pressure Driven Desalination Membranes: Lyotropic Liquid Crystals Containing Single Walled Carbon, 2021 California Polytechnic State University, San Luis Obispo
Pressure Driven Desalination Membranes: Lyotropic Liquid Crystals Containing Single Walled Carbon, Matteo A. Del Giudice, Samantha Castillo Merigold
This project presents a potential alternative desalination technique that utilizes the ion rejection properties of single walled carbon nanotubes dispersed in a lyotropic liquid crystal (LLC) matrix. Previous research has pointed to the polymerizable surfactant methacryloxy ethyl hexadecyl dimethyl ammonium bromide (C16MA) having capabilities of filtering molecular components smaller than a nanometer, when oriented in cylindrical micelles. SWCNTs were dispersed in deionized water by probe sonication and addition of surfactant cetyltrimethylammonium bromide (CTAB) due to SWCNTs’ hydrophobic properties. Membranes were produced containing 55wt% C16MA, 37wt% DI water, 0.1wt% with respect to the monomer (WRM) SWCNTs, 1.9 wt% WRM ...
Effects Of Uv Exposure On The Thermo-Mechanical Properties Of Cactus Based Biopolymers, 2021 California Polytechnic State University, San Luis Obispo
Effects Of Uv Exposure On The Thermo-Mechanical Properties Of Cactus Based Biopolymers, Madison Glozer, Megan Bolling, Addison Wolfson
The viability of renewable biopolymers as sustainable alternatives to synthetic plastics is promising, however ultra-violet (UV) radiation can lead to premature degradation and reduction in the material’s performance. Biopolymers comprised of nopal cactus juice, animal protein, natural wax, and glycerin in differing percentages were studied to obtain thermo-mechanical data in relation to UV exposure. To quantify degradation, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, goniometry and gravimetric measurements were performed. Each formulation experienced mass loss as a result of UV exposure, which could be attributed to water evaporation. The thermogravimetric analysis indicated a reduction in the ...
Analysis Of The Use Of Waste Material In 3d Printing, 2021 California Polytechnic State University, San Luis Obispo
Analysis Of The Use Of Waste Material In 3d Printing, Alexander Laurence
Globally, only 9% of plastic by mass is recycled. Allowing consumers to directly convert polyethylene terephthalate (PET) waste into 3D filament can increase the recycling rate by reducing contamination and costs from traditional large-scale recycling methods. This was tested by heating strips of PET to various temperatures within its glass transition region and pressing a roller with a 1.75 mm indentation against it to observe strip deformation. PET was also placed in a hemispherical well with a 1.75 mm diameter hole at the bottom and heated above its melting temperature to determine the mass of PET required to ...
Strengthening Of 7175 Aluminum Alloy Through Multi-Step Aging Process, 2021 California Polytechnic State University, San Luis Obispo
Strengthening Of 7175 Aluminum Alloy Through Multi-Step Aging Process, Colin E. Masterson, Ryland W. Jolliffe
7175 is a heat-treatable aluminum alloy commonly used in aerospace forgings. This alloy is aged with a multi-step heat treatment. This treatment must balance strength with stress corrosion cracking resistance through a degree of overaging. The team was tasked by Weber Metals to increase the strength of this treatment without sacrificing stress corrosion cracking resistance. Both two-step and retrogression and reaging treatments were tested in experiments to find a heat treatment that could increase the yield and tensile strength by 1-2 ksi while maintaining a minimum electrochemical conductivity equivalence of 38% relative to copper. Two-step aging is the more conventional ...
Development Of A Marine Biodegradable Target Balloon, 2021 California Polytechnic State University, San Luis Obispo
Development Of A Marine Biodegradable Target Balloon, Blake Samuel Robinson, Arash Sam Akhavi, David Leonardo Albarran-Martinez
The US Navy utilizes PVC target balloons, known as Killer Tomatoes, that are inflated onboard a naval vessel then deployed into the ocean to calibrate a variety of weaponry. The Navy has requested the investigation of biodegradable polymers to replace the PVC in attempts to reduce ocean waste that is generated from the leftover PVC material. After communicating with American Pacific Plastic Fabricators (APPF), the current manufacturer of the Killer Tomatoes, we gained an understanding of the manufacturing process and the material requirements that would allow a new material to be integrated into their current process. Two proprietary, trial polymers ...
Use Of Biomimicry Design Approach In Constructing Sustainable Resilient Structures (Case Study: Port Of Beirut), 2021 Master's Student, Faculty of Architecture - Design & Built Environment, Beirut Arab University, Lebanon
Use Of Biomimicry Design Approach In Constructing Sustainable Resilient Structures (Case Study: Port Of Beirut), Farouk Bader, Marwan Halabi, Hiba Mohsen, Maged Youssef
BAU Journal - Creative Sustainable Development
Resiliency is not the same as sustainability, nor its substitute, but definitely the two concepts complement each other’s. Sustainability is the avoidance of depletion of natural resources to maintain ecological balance whereas resiliency is to recover, adapt and keep going in the face of setbacks. While designing with green approach is important but what will happen to leed points if the building becomes uninhabitable due to disasters, that’s where resiliency comes into play. The 2019 statistics showed that natural disasters accounted for 133 billion dollars losses and manmade ones accounted for other 7 billion in addition to 11 ...
Control Of Polarization In Bulk Ferroelectrics By Mechanical Dislocation Imprint, 2021 Technical University of Darmstadt
Control Of Polarization In Bulk Ferroelectrics By Mechanical Dislocation Imprint, Marion Höfling, Xiandong Zhou, Lukas M. Riemer, Enrico Bruder, Binzhi Liu, Lin Zhou, Pedro B. Groszewicz, Fangping Zhuo, Bai-Xiang Xu, Karsten Durst, Xiaoli Tan, Dragan Damjanovic, Jurij Koruza, Jürgen Rödel
Materials Science and Engineering Publications
Defects are essential to engineering the properties of functional materials ranging from semiconductors and superconductors to ferroics. Whereas point defects have been widely exploited, dislocations are commonly viewed as problematic for functional materials and not as a microstructural tool. We developed a method for mechanically imprinting dislocation networks that favorably skew the domain structure in bulk ferroelectrics and thereby tame the large switching polarization and make it available for functional harvesting. The resulting microstructure yields a strong mechanical restoring force to revert electric field–induced domain wall displacement on the macroscopic level and high pinning force on the local level ...
Targeted Microfluidic Manufacturing To Mimic Biological Microenvironments: Cell-Encapsulated Hollow Fibers, 2021 Iowa State University
Targeted Microfluidic Manufacturing To Mimic Biological Microenvironments: Cell-Encapsulated Hollow Fibers, Marilyn C. Mcnamara, Saurabh S. Aykar, Reza Montazami, Nicole N. Hashemi
Mechanical Engineering Publications
At present, the blood–brain barrier (BBB) poses a challenge for treating a wide range of central nervous system disorders; reliable BBB models are still needed to understand and manipulate the transfer of molecules into the brain, thereby improving the efficiency of treatments. In this study, hollow, cell-laden microfibers are fabricated and investigated as a starting point for generating BBB models. The genetic effects of the manufacturing process are analyzed to understand the implications of encapsulating cells in this manner. These fibers are created using different manufacturing parameters to understand the effects on wall thickness and overall diameter. Then, dopaminergic ...
Mash 2016 Test Level 3 And Test Level 4 Evaluation Of Roadside Safety Barrier With Pedestrian Features, 2021 University of Nebraska-Lincoln
Mash 2016 Test Level 3 And Test Level 4 Evaluation Of Roadside Safety Barrier With Pedestrian Features, Miguel Angel Hinojosa Palacios
Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research
The Minnesota Department of Transportation (MnDOT) desires to use a vehicle, bicycle, and pedestrian combination bridge railing system along pedestrian and bicycle bridge paths. The system was evaluated per MASH 2016.
In full-scale crash test no. MNPD-3, the system was evaluated according to MASH test designation no. 3-11. The 2014 Dodge Ram 1500 crew cab pickup truck impacted the system 71¼ in. upstream from the centerline of post no. 4 with a speed of 63.4 mph at an angle of 25.3 degrees. The combination railing system was found to meet the AASHTO MASH 2016 TL-3 impact safety criteria ...
Composite Elastomer Materials Based On New Ingredients, 2021 Tashkent Chemiсal-Technological Institute, Tashkent, Uzbekistan
Composite Elastomer Materials Based On New Ingredients, Akhmadjon Ibadullaev, Elmira Teshabaeva, Murodjon Vapaev
CHEMISTRY AND CHEMICAL ENGINEERING
The results of a study present the effect of new modified ingredients on the complex of properties of composite elastomeric materials. Methods for modifying mineral fillers have developed. It found that the introduction of modified ingredients into the composition of elastomeric compositions enhances the interfacial interaction at the “rubber-filler” interface and the formation of additional bonds between rubber macromolecules and functional groups, resulting in an improvement in the complex of properties of the compositions. New accelerators, activators for vulcanization of rubbers and plasticizers with stabilizing properties have proposed, and their optimal contents in the composition have determined.
Composition For Protecting Technological Equipment Against Salt Deposits And Internal Corrosion, 2021 Tashkent Chemical-Technological Institute, Tashkent, Uzbekistan
Composition For Protecting Technological Equipment Against Salt Deposits And Internal Corrosion, Hasan Kadirov, Sadritdin Turabdjanov
CHEMISTRY AND CHEMICAL ENGINEERING
Aimed studies on the synthesis of metal complexonates have carried out. The reaction of obtaining zincate zincate oxyethylene diphosphonic acid OEDP has studied. On the basis of synthesized zincate-OEDP, compositions of corrosion inhibitors and deposits of mineral salts with the addition of a vacuum residue of monoethanolamine (RMEA) and polyaminocrotanol (PKI-3), which are able to effectively suppress corrosion processes in environments with different initial corrosive activity, have been compiled. It is proved that the high efficiency of the composition OEDP : zincate-OEDP : PKI-3 (maximum protective effect - 97.9%) is much more effective than the composition OEDP : zincate-OEDP : RMEA (maximum protective effect ...
Rational Disposal Of Pet Containing Waste And Prospects For The Synthesis Of New Polymers, 2021 Tashkent Chemical-Technological Institute, Tashkent, Uzbekistan
Rational Disposal Of Pet Containing Waste And Prospects For The Synthesis Of New Polymers, Asror Juraev, Muzaffar Alimukhamedov, Ravshan Adilov, Farhod Magrupov
CHEMISTRY AND CHEMICAL ENGINEERING
As a result of the research on the utilization of polyethylene terephthalate-containing household waste, a promising direction was identified in the production of a new type of secondary polyethylene terephthalate (SPET) - unsaturated polyesters.It was revealed that the final product, which formed when the alcoholization process is complete in any proportion of of glycol and secondary polyethylene terephthalate, is the bisalkylent terephthalate of terephthalic acid; the content of the alcoholysis product consists of bisalkylent terephthalate, different molecule mass, functionally hydroxyl-containing complex polyester polyol and free diols.
The laws of alcoholization of secondary polyethylene terephthalate have been studied and ...