Engineering Physics Commons^™

Air And Air-Steam Gasification Of Coconut Shell In A Fluidized Bed, Keynty Boy V. Magtoto, Rossana Marie C. Amongo, Sergio C. Capareda, Ronaldo B. Saludes

The Philippine Agricultural Scientist

Coconut shells’ abundance in tropical countries, along with its high volatile combustible matter (83.51%) and energy content (18.68 MJ kg^-1) make it a good biomass resource and a promising feedstock for gasification. In gasification, different mediums such as air, steam, oxygen, or their combinations can be used to react with the solid carbon and heavy hydrocarbons of biomass. Hence, the effects of using an air-steam mixture as a gasifying agent for the bench-scale fluidized bed gasification of coconut shells were studied. The steam-to-carbon ratio (SCR) was varied to evaluate its effect on the resulting syngas quality and gasification …

Effects Of Drying Temperature And Tempering Duration On Hybrid Rice Seed Germination, Thin-Layer Drying Characteristics, And Power Requirement, Rina A. Bawar, Joanne P. Foliente, Kevin F. Yaptenco, Mitchie Ann L. Cabiles

The Philippine Agricultural Scientist

This study presents the results of thin-layer drying tests for hybrid rice seeds. The independent factors were drying air temperature (45, 55, and 65 °C) and tempering duration (1, 2, and 4 h), while the dependent parameters were seed germination and drying characteristics, including drying rate, total and effective drying operation times, and power requirement. Considering one hybrid and 3 mo storage period after drying, the results showed that samples continuously dried at 45 and 55°C resulted in 91 and 86% germination percentages, respectively, which were above the acceptable Philippine national standard of at least 85%. However, when tempered for …

Towards An Understanding Of The Thermodynamic Properties Of Crtao4: A Computational Perspective, Tanner B. Gordon

Theses and Dissertations

Materials that can withstand higher temperatures are paramount for next-generation aircraft design. Hypersonic capabilities and jet-turbine engines operate in extreme environments. Choosing materials that have high thermal stability and oxidation resistance for these applications can increase engine efficiency, reduce size, weight and power (SWaP), and increase the maneuverability of the aircraft. The mixed oxide CrTaO₄ has been experimentally observed to significantly contribute to oxidation resistance at high temperatures. However, and despite its significance, its properties remain largely unknown. This work explores the thermal properties of this material from a multi-scale approach, by obtaining an accurate description of the thermodynamics …

Coupling To Quantum Topological Order In Superconducting Qubit Systems, Seth T. Hyra

Theses and Dissertations

The coupling of superconducting qubits to non-trivial topological phases offers a means of improving existing quantum computational capabilities in lieu of a fully realized topological quantum computer. I will show that although such systems do not completely avoid the necessary errors associated with an energetic qubit basis, they do provide a potential avenue for decoherence free quantum memory. Further, the physics behind such systems enables exploration of the nature of non-Abelian anyons, as well as the remaining challenges in realization of true topological quantum computation.

Hawc Detection Of A Tev Halo Candidate Surrounding A Radio-Quiet Pulsar, A. Albert, R. Alfaro, J. C. Arteaga-Velázquez, H. A. Ayala Solares, E. Belmont-Moreno, T. Capistrán, A. Carramiñana, S. Casanova, J. Cotzomi, S. Coutiño De León, E. De La Fuente, C. De León, R. Diaz Hernandez, M. A. Duvernois, J. C. Díaz-Vélez, C. Espinoza, K. L. Fan, N. Fraija, K. Fang, J. A. Garcia-Gonzalez, F. Garfias, A. Jardin-Blicq, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez, D. Huang, F. Hueyotl-Zahuantitla, P. Huntemeyer, A. Iriarte, V. Joshi, A. Lara, J. Lee, H. Leon Vargas, J. T. Linneman, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martinez-Castro, J. A. Matthews, J. A. Morales-Soto, E. Moreno, M. Mostafa, A. Nayerhoda, L. Nellen, M. Newbold, M. U. Nisa, Y. Perez Araujo, Y. Son, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, A. Sandoval, M. Schneider, J. Serna-Franco, A. J. Smith, R. W. Springer, K. Tollefson, I. Torres, R. Torres-Escobedo, Xiaojie Wang, K. Whitaker, E. Willox, H. Zhou

Physics Faculty Research & Creative Works

Extended very-high-energy (VHE; 0.1-100 TeV) γ-ray emission has been observed around several middle-aged pulsars and referred to as "TeV halos." Their formation mechanism remains under debate. It is also unknown whether they are ubiquitous or related to a certain subgroup of pulsars. With 2321 days of observation, the High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory detected VHE γ-ray emission at the location of the radio-quiet pulsar PSR J0359+5414 with >6σ significance. By performing likelihood tests with different spectral and spatial models and comparing the TeV spectrum with multiwavelength observations of nearby sources, we show that this excess is consistent with a …

Search For Gamma-Ray And Neutrino Coincidences Using Hawc And Antares Data, H. A. Ayala Solares, S. Coutu, D. Cowen, D. B. Fox, T. Grégoire, F. Mcbride, M. Mostafá, K. Murase, S. Wissel, A. Albert, S. Alves, M. André, M. Ardid, S. Ardid, J. J. Aubert, J. Aublin, B. Baret, S. Basa, B. Belhorma, M. Bendahman, F. Benfenati, V. Bertin, S. Biagi, M. Bissinger, J. Boumaaza, M. Bouta, M. C. Bouwhuis, H. Branzas, R. Bruijn, J. Brunner, J. Busto, B. Caiffi, D. Calvo, A. Capone, L. Caramete, J. Carr, V. Carretero, S. Celli, M. Chabab, T. N. Chau, R. Cherkaoui El Moursli, T. Chiarusi, M. Circella, J. A. B. Coelho, A. Coleiro, R. Coniglione, P. Coyle, A. Creusot, A. F. Diaz, G. De Wasseige, B. De Martino, C. Distefano, I. Di Palma, A. Domi, C. Donzaud, D. Dornic, D. Drouhin, T. Eberl, T. Van Eeden, D. Van Eijk, N. El Khayati, A. Enzenhofer, P. Fermani, G. Ferrara, F. Filippini, L. Fusco, J. Garcia, P. Gay, H. Glotin, R. Gozzini, R. Gracia Ruiz, K. Graf, C. Guidi, S. Hallmann, H. Van Haren, A. J. Heijboer, Y. Hello, J. J. Hernandez-Rey, J. Hobl, J. Hofestadt, F. Huang, G. Illuminati, C. W. James, B. Jisse-Jung, M. De Jong, P. De Jong, M. Kadler, O. Kalekin, U. Katz, A. Kouchner, I. Kreykenbohm, V. Kulikovskiy, R. Lahmann, M. Lamoureux, R. Le Breton, D. Lefevre, E. Leonora, G. Levi, S. Le Stum, D. Lopez-Coto, S. Loucatos, L. Maderer, J. Manczak, M. Marcelin, A. Margiotta, A. Marinelli, J. A. Martinez-Mora, K. Melis, P. Migliozzi, A. Moussa, R. Muller, L. Nauta, S. Navas, E. Nezri, B. O Fearraigh, A. Paun, G. E. Pavalas, C. Pellegrino, M. Perrin-Terrin, V. Pestel, P. Piattelli, C. Pieterse, C. Piore, V. Popa, T. Pradier, N. Randazzo, D. Real, S. Reck, G. Riccobene, A. Romanov, A. Sanchez-Losa, D. F. E. Samtleben, M. Sanguineti, P. Sapienza, J. Schnabel, J. Schumann, F. Schussler, J. Seneca, M. Spurio, Th. Stolarczyk, M. Taiuti, Y. Tayalati, S. J. Tingay, B. Vallage, V. Van Elewyck, F. Versari, S. Viola, D. Vivolo, J. Wilms, S. Zavatarelli, A. Zegarelli, J. D. Zornoza, J. Zuniga, A. Albert, C. Alvarez, J. C. Arteaga-Velazquez, R. Babu, E. Belmont-Moreno, K. S. Caballero-Mora, T. Capistran, A. Carraminana, S. Casanova, U. Cotti, O. Chaparro-Amaro, J. Cotzomi, S. Coutino De Leon, E. De La Fuenta, C. De Leon, R. Diaz Hernandez, M. A. Duvernois, M. Durocher, J. C. Diaz-Velez, K. Engel, C. Espinoza, K. L. Fan, M. Fernandez Alonso, N. Fraija, J. A. Garcia-Gonzalez, F. Garfias, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez, D. Huang, F. Hueyotl-Zahuantitla, P. Huntemeyer, A. Iriarte, V. Joshi, S. Kaufmann, A. Lara, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, I. Martinez-Castellanos, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Morales-Soto, E. Moreno, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, A. Peisker, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, H. Salazar, F. Salesa Greus, A. Sandoval, M. Schneider, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, Xiaojie Wang, K. Whitaker, E. Willox, A. Zepeda, H. Zhou

Physics Faculty Research & Creative Works

In the quest for high-energy neutrino sources, the Astrophysical Mult messenger Observatory Network has implemented a new search by combining data from the High-Altitude Water Cherenkov (HAWC) Observatory and the Astronomy with a Neutrino Telescope and Abyss environmental RESearch (ANTARES) neutrino telescope. Using the same analysis strategy as in a previous detector combination of HAWC and IceCube data, we perform a search for coincidences in HAWC and ANTARES events that are below the threshold for sending public alerts in each individual detector. Data were collected between 2015 July and 2020 February with a live time of 4.39 yr. Over this …

The Rise And Stall Of World Electricity Efficiency:1900–2017, Results And Insights For The Renewables Transition, Ricardo Pinto, Sofia T. Henriques, Paul E. Brockway, Matthew Kuperus Heun, Tania Sousa

University Faculty Publications and Creative Works

In the coming renewables-based energy transition, global electricity consumption is expected to double by 2050, entailing widespread end-use electrification, with significant impacts on energy efficiency. We develop a longrun, worldwide societal exergy analysis focused on electricity. Our 1900–2017 electricity world database contains the energy carriers used in electricity production, final end-uses, and efficiencies. We find world primary-tofinal exergy (i.e. conversion) efficiency increased rapidly from 1900 (6%) to 1980 (39%), slowing to 43% in 2017 as power station generation technology matured. Next, despite technological evolution, final-to-useful end-use efficiency was surprisingly constant (~48%), due to “efficiency dilution”, wherein individual end-use efficiency gains …

Numerical Study Of Owls’ Leading-Edge Serrations, Asif Shahriar Nafi

Electronic Theses and Dissertations

The silent flight ability of owls is often attributed to their unique wing morphology and its interaction with their wingbeat kinematics. Among these distinctive morphological features, leading-edge serrations stand out – these are rigid, miniature, hook-like patterns located at the leading edge of the primary feathers of their wings. It had been hypothesized that these leading-edge serrations serve as a passive flow control mechanism, influencing the aerodynamic performance and potentially affecting the boundary layer development over the wing, subsequently influencing wake flow dynamics. Despite being the subject of research spanning multiple decades, a consensus regarding the aerodynamic mechanisms underpinning owls’ …

Gamelan Gong Directivity Dataset, Samuel D. Bellows, Dallin T. Harwood, Kent L. Gee, Micah R. Shepherd

Directivity

No abstract provided.

Entropy-Driven Structural Transition From Tetragonal To Cubic Phase: High Thermoelectric Performance Of Cucdinse3 Compound, Tingting Luo, Yihao Hu, Shi Liu, Fanjie Xia, Junhao Qiu, Haoyang Peng, Keke Liu, Quansheng Guo, Xingzhong Li, Dongwang Yang, Xianli Su, Jinsong Wu, Xinfeng Tang

Nebraska Center for Materials and Nanoscience: Faculty Publications

Cu based chalcopyrite is an important class of thermoelectric materials with excellent electronic properties, however, the thermal conductivity is relatively high due to the simple tetragonal structure with highly ordered configuration on cation sites, limiting the thermoelectric performance. Herein, we realize that the modulation of entropy via alloying CdSe achieves the structural transition from tetragonal structure with ordered configuration on cations sites in CuInSe₂ compound to cubic CuCdInSe₃. CuCdInSe₃ crystallizes in a zinc blende (ZnS) structure where Cu, Cd and In cations randomly occupy the Zn site with the occupancy fraction 1/3. This entropy driven order-disorder …

New Features In Landyne 5 - A Software Suite For Materials Characterization And Crystallography By Transmission Electron Microscopy, Xing-Zhong Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

Landyne software suite (version 5) includes fifteen standalone computer programs for materials characterization and crystallography by transmission electron microscopy [1]. A launcher interface is provided for users to access all components conveniently. The purpose of this software suite is twofold: i) as research tools to analyze experimental results, ii) as teaching tools to explore the varieties of electron diffraction methods and crystallographic image processing principles.

The Landyne suite previously included: PTable, an interactive periodic table of elements; SVAT, a structural visual and analytical tool; SAED and PCED, simulation and analysis of electron diffraction (spot and ring) patterns; QSAED and QPCED, …

Structural, Electronic, And Magnetic Properties Of Cofevge-Based Compounds: Experiment And Theory, Parashu Kharel, Zachary Lehmann, Gavin Baker, Lukas Stuelke, Shah R. Valloppilly, Paul M. Shand, Pavel V. Lukashev

Nebraska Center for Materials and Nanoscience: Faculty Publications

We have carried out a combined theoretical and experimental investigation of both stoichiometric and nonstoichiometric CoFeVGe alloys. In particular, we have investigated CoFeVGe, Co_1.25Fe_0.75VGe, Co_0.75Fe_1.25VGe, and CoFe_0.75VGe bulk alloys. Our first principles calculations suggest that all four alloys show ferromagnetic order, where CoFeVGe, Co_1.25Fe_0.75VGe, and Co_0.75Fe_1.25VGe are highly spin polarized with spin polarization values of over 80%. However, the spin polarization value of CoFe_0.75VGe is only about 60%. We have synthesized all four samples using arc melting and high-vacuum annealing …

Tem Studies Of A New Modulated Structure In Mn2Rusn Alloy And Intermetallic Phases In Fe3+XCo3–XTi2 (X = 0, 1, 2, 3) Alloys, Xing-Zhong Li, Shah R. Valloppilly

Nebraska Center for Materials and Nanoscience: Faculty Publications

Heusler compounds are a remarkable class of intermetallic materials with wide-ranging and tunable properties. The Mn₂RuSn Heusler compound was reported as an L2₁B-type cubic phase, a = 0.62195 nm, distinguishing from the original L2₁ structure (or L2₁A-type). The L2₁B-type structure is a disordered variant of the inverse Heusler structure, XA-type (Prototype-CuHg₂Ti, space group No. 216, F4–3m).

In our recent work [1], we observed a new modulated structure derived from the XA-type structure and its orthogonal domains in the Mn₂RuSn Heusler alloy. The structural characterization was carried out …

Development Of Spintronic Materials By Stoichiometric Engineering Of Cofeval, Gavin Baker, Matthew Wieberdink, Jax Wysong

The Journal of Undergraduate Research

We have carried out an experimental investigation of the Heusler Alloy CoFeVAl and its two variants Co_1.5Fe_0.5VAl and CoFeVAl_0.5Si_0.5 for their potential application in the field of spintronics. Heusler alloys are investigated for their many remarkable properties, including half-metallicity and spin-gapless semi-conductivity. Spintronic technology utilizes the intrinsic spin of an electron for information storage and manipulation in solid state devices. We synthesized these alloys using arc-melting and annealing. All three alloys were found to have cubic crystal structures with varying disorders. The parent alloy CoFeVAl shows a magnetic transition at 65 K. However, …

Modeling A Nb3Sn Cryounit In Gpt At Uitf, Sunil Pokharel, A. S. Hofler, Geoffrey A. Krafft

Physics Faculty Publications

Nb₃Sn is a prospective material for future superconducting radio frequency (SRF) accelerator cavities. Compared to conventional niobium, the material can achieve higher quality factors, higher temperature operation, and potentially higher accelerating gradients (E_acc ≈ 96 MV/m). In this work, we performed modeling of the Upgraded Injector Test Facility (UITF) at Jefferson Lab utilizing newly constructed Nb₃Sn cavities. We studied the effects of the buncher cavity and varied the gun voltage from 200-500 keV. We have calibrated and optimized the SRF cavity gradients and phases for the Nb₃Sn five-cell cavities' energy gains with the …

Cavity And Cryomodule Developments For Eic, R. A. Rimmer, E. Daly, J. Guo, J. Henry, J. Matalevich, H. Wang, S. Wang, D. Holmes, K. Smith, W. Xu, A. Zaltsman, B. Xiao, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

The EIC is a major new project under construction at BNL in partnership with JLab. It relies upon a number of new SRF cavities at 197 MHz, 394 MHz, 591 MHz and 1773 MHz to pre-bunch, accelerate, cool and crab the stored beams. R&D is focusing on the 591 MHz elliptical cavity and 197 MHz crab cavity first as these are the most challenging. Preliminary designs of these cavities are presented along with an R&D status report. To avoid developing multiple different cryostats a modular approach is adopted using a high degree of commonality of parts and systems. This approach …

Quantum Efficiency Enhancement In Simulated Nanostructured Negative Electron Affinity Gaas Photocathodes, Md Aziz Ar Rahman, Shukui Zhang, Hani E. Elsayed-Ali

Physics Faculty Publications

Nanostructured negative electron affinity GaAs photocathodes for a polarized electron source are studied using finite difference time domain optical simulation. The structures studied are nanosquare columns, truncated nanocones, and truncated nanopyramids. Mie-type resonances in the 700–800 nm waveband, suitable for generation of polarized electrons, are identified. At resonance wavelengths, the nanostructures can absorb up to 99% of the incident light. For nanosquare columns and truncated nanocones, the maximum quantum efficiency (QE) at 780 nm obtained from simulation is 27%, whereas for simulated nanopyramids, the QE is ∼21%. The high photocathode quantum efficiency is due to the shift of Mie resonance …

Generation And Characterization Of Magnetized Electron Beam From A Dc High Voltage Photogun For Electron Beam Cooling Application, S.A.K. Wijethunga, M. A. Mamun, R. Suleiman, P. Adderley, B. Bullard, J. Benesch, Jean R. Delayen, J. Grames, C. Hernandez-Garcia, F. Hannon, Geoffrey A. Krafft, G. Palacios-Serrano, M. Poelker, M. Stefani, Y. Wang, S. Zhang

Physics Faculty Publications

One of the most challenging requirements for the proposed Electron–Ion Collider is the strong cooling of the proton beam, which is key to achieving the collider’s desired luminosity of order 10³³–10³⁴cm⁻²s⁻¹. Magnetized bunched-beam electron cooling could be a means to achieve the required high luminosity, where strong cooling is accomplished inside a cooling solenoid where the ions co-propagate with an electron beam generated from a source immersed in a magnetic field. To increase the cooling efficiency, a bunched electron beam with high bunch charge and high repetition rate is required. This work …

Development Of A Prototype Superconducting Radio-Frequency Cavity For Conduction Cooled Accelerators, Gianluigi Ciovati, J. Anderson, S. Balachandran, G. Cheng, B. Coritron, E. Daly, P. Dhakal, Alex Gurevich, F. Hannon, K. Harding, L. Holland, F. Marhauser, K. Mclaughlin, D. Packard, T. Powers, U. Pudasaini, J. Rathke, R. Rimmer, T. Schultheiss, H. Vennekate, D. Vollmer

Physics Faculty Publications

The higher efficiency of superconducting radio-frequency (SRF) cavities compared to normal -conducting ones enables the development of high-energy continuous-wave linear accelerators (linacs). Recent progress in the development of high-quality Nb₃Sn film coatings along with the availability of cryocoolers with high cooling capacity at 4 K makes it feasible to operate SRF cavities cooled by thermal conduction at relevant accelerating gradients for use in accelerators. A possible use of conduction-cooled SRF linacs is for environmental applications, requiring electron beams with energy of 1-10 MeV and 1 MW of power. We have designed a 915 MHz SRF linac for such …

Investigation Of The Multilayer Shielding Effect Through Nbtin-Ain Coated Bulk Niobium, Iresha Harshani Senevirathne, D. R. Beverstock, A-M Valente-Feliciano, Alex Gurevich, Jean R. Delayen

Physics Faculty Publications

We report measurements of the dc field onset B_p of magnetic flux penetration through NbTiN-AlN coating on bulk niobium using the Hall probe experimental setup. The measurements of B_p reveal the multilayer shielding effect on bulk niobium under high magnetic fields at cryogenic temperatures. We observed a significant enhancement in B_p for the NbTiN-AlN coated Nb samples as compared to bare Nb samples. The observed dependence of B_p on the coating thickness is consistent with theoretical predictions.