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Articles 1 - 21 of 21

Full-Text Articles in Engineering Physics

Real Bullets, Plastic Guns: Evaluating The Strength Of 3-D Printed Gun Parts, Maria Latenia Mayol Aug 2026

Real Bullets, Plastic Guns: Evaluating The Strength Of 3-D Printed Gun Parts, Maria Latenia Mayol

Student Theses

Privately made firearms (PMFs), often referred to as “ghost guns,” are firearms manufactured or assembled by individuals rather than federally licensed manufacturers. Although the terms are frequently used interchangeably, “ghost gun” more specifically describes an unserialized firearm, whereas PMFs include a broader range of firearms produced through nontraditional manufacturing methods. PMFs may be entirely 3-D printed, assembled from partially completed firearm kits, or constructed by integrating additively manufactured components with commercially manufactured firearm parts. The increasing accessibility of additive manufacturing and widespread dissemination of computer-aided design files have raised concerns about concealment, regulation, and forensic evasion, particularly when factory-manufactured components …


Silver-Alloyed Cigs Thin-Film Solar Cells On Flexible Stainless-Steel Substrate, Zhi Huang Feb 2025

Silver-Alloyed Cigs Thin-Film Solar Cells On Flexible Stainless-Steel Substrate, Zhi Huang

Dissertations, Theses, and Capstone Projects

Our dissertation demonstrates the optimization of ACIGS (Ag-Cu-In-Ga-Se) thin-film solar cells, achieving an efficiency of 20.4% through the combined effects of silver incorporation and alkali metal post-deposition treatment (PDT). The incorporation of 2.8% Ag into the CIGS lattice enhanced crystal quality, reduced disorder, and widened the bandgap by 0.103 eV, as evidenced by a significant reduction in Urbach energy. These improvements resulted in stronger light absorption, increased carrier generation, and enhanced photovoltaic parameters, including a short-circuit current density Jsc of 35.31 mA/cm², an open-circuit voltage Voc of 0.74 V, and a fill factor (FF) of 75.8%. PDT using rubidium fluoride …


Electromagnetic Theory And Applications, 2nd Edition, Nicholas Madamopoulos, George Kliros Sep 2024

Electromagnetic Theory And Applications, 2nd Edition, Nicholas Madamopoulos, George Kliros

Open Educational Resources

This book intends to provide both the fundamentals of Electromagnetics but also some practical applications of the concepts covered. Having taught electromagnetics for several years, the authors feel that many times the field of electromagnetics comes as “old” and often times students do not appreciate the concepts and their importance in everyday applications. The authors intend to accompany the EM concepts with life applications. Hence, students may see the direct impact of the knowledge they acquire through the study of the field of electromagnetics and better appreciate the field.


Hydrodynamics Of Drops And Particles Driven By Marangoni And Diffusiophoretic Forces, Subramaniam Chembai Ganesh Jan 2024

Hydrodynamics Of Drops And Particles Driven By Marangoni And Diffusiophoretic Forces, Subramaniam Chembai Ganesh

Dissertations and Theses

This study investigates the hydrodynamics of particles and drops driven by forces generated by an asymmetrical physical and chemical surrounding environment. In the first part, a novel colloidal motor design driven by surface tension forces is proposed, utilizing an active Janus particle encapsulated in an immiscible liquid drop to form a compound drop/particle. Marangoni forces induced by asymmetric solute adsorption at the liquid-liquid interface of the drop propels the compound system. The propulsion speeds of the motor are analyzed for various relative sizes and configurations of the Janus particle and the encapsulating drop and the effects of varying the transport …


Robust Zero Modes In Non-Hermitian Systems Without Global Symmetries, Jose D. H. Rivero, Courtney Fleming, Bingkun Qi, Liang Feng, Li Ge Nov 2023

Robust Zero Modes In Non-Hermitian Systems Without Global Symmetries, Jose D. H. Rivero, Courtney Fleming, Bingkun Qi, Liang Feng, Li Ge

Publications and Research

We present an approach to achieve zero modes in lattice models that do not rely on any symmetry or topology of the bulk, which are robust against disorder in the bulk of any type and strength. Such symmetry-free zero modes (SFZMs) are formed by attaching a single site or small cluster with zero mode(s) to the bulk, which serves as the “nucleus” that expands to the entire lattice. We identify the requirements on the couplings between this boundary and the bulk, which reveals that this approach is intrinsically non-Hermitian. We then provide several examples with either an arbitrary or structured …


Non-Hermitian Gauged Laser Arrays With Localized Excitations: Anomalous Threshold And Generalized Principle Of Selective Pumping, Li Ge, Zihe Gao, Liang Feng Sep 2023

Non-Hermitian Gauged Laser Arrays With Localized Excitations: Anomalous Threshold And Generalized Principle Of Selective Pumping, Li Ge, Zihe Gao, Liang Feng

Publications and Research

We investigate non-Hermitian skin modes in laser arrays with spatially localized excitation. Intriguingly, we observe an unusual threshold behavior when selectively pumping either the head or the tail of these modes: both cases exhibit the same lasing threshold and hence defy the conventional principle of selective pumping, which aims to maximize the overlap between the pump profile and the target lasing mode. To shed light on this enigma, we reveal a previously overlooked phenomenon, i.e., energy exchange at non-Hermitian coupling junctions with the photonic environment, which does not occur with uniform gain or loss. Utilizing a transfer matrix approach, we …


Topological Shadow Of Higher-Order Topological Phases And Non-Hermitian Phases Protected By Generalized Rotational Symmetry, Kai Chen Sep 2022

Topological Shadow Of Higher-Order Topological Phases And Non-Hermitian Phases Protected By Generalized Rotational Symmetry, Kai Chen

Dissertations, Theses, and Capstone Projects

Topological phenomena in condensed matter physics have been investigated intensively in the past decades since the discovery of the integer quantum Hall effect (IQHE). For the IQHE, the energy band can be characterized by its topological invariants (Chern number or TKNN invariant), which relates to the quantized Hall conductance directly. Later, this expression was recognized as the first Chern class of a U(1) principal fiber bundle on a torus, where the fibers and torus correspond respectively to the magnetic Bloch waves and the magnetic Brillouin zone. And then, the discoveries of time-reversal symmetric topological insulators in two and three dimensions …


High Water-Responsiveness Of Peptidoglycan And Its Water-Responsive Mechanism, Haozhen Wang Sep 2022

High Water-Responsiveness Of Peptidoglycan And Its Water-Responsive Mechanism, Haozhen Wang

Dissertations, Theses, and Capstone Projects

Water-responsive materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. This thesis demonstrates that peptidoglycan exhibits ultrahigh water-responsive actuation energy and power densities, which are orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. Surprisingly, peptidoglycan exhibits an energy conversion efficiency of ~66.8%, which could be attributed to its super-viscous nanoconfined water that efficiently translates water’s movement to peptidoglycan’s mechanical deformation. The systematic water-responsive characterizations of peptidoglycan from different microorganisms and peptide crystals indicate that enhanced H-bonding interactions in water-responsive …


Nmr Characterization Of Novel Materials For Battery Electrolyte Applications, Sahana Bhattacharyya Sep 2022

Nmr Characterization Of Novel Materials For Battery Electrolyte Applications, Sahana Bhattacharyya

Dissertations, Theses, and Capstone Projects

The extensive application of renewable and non-renewable energy storage devices in commercial products and services and the global warming have created significant motivations to accelerate research in battery technology. In addition, the risk factors generated by the high heat generation and flammability of the batteries are being addressed by inventing new renewable or non-renewable energy resources that do not release greenhouse gases into the atmosphere. This thesis discusses the applications of Nuclear Magnetic Resonance (NMR) Spectroscopy in characterizing and understanding novel battery materials as potential battery electrolytes. Works discussed include: the variable temperature characterization of water-based solid polymer electrolyte for …


A Monolithic 3d Printed Axisymmetric Co-Flow Single And Compound Emulsion Generator, Amirreza Ghaznavi, Yang Lin, Mark Douvidzon, Adam Szmelter, Alannah Rodrigues, Malik Blackman, David Eddington, Tal Carmon, Lev Deych, Lan Yang, Jie Xu Jan 2022

A Monolithic 3d Printed Axisymmetric Co-Flow Single And Compound Emulsion Generator, Amirreza Ghaznavi, Yang Lin, Mark Douvidzon, Adam Szmelter, Alannah Rodrigues, Malik Blackman, David Eddington, Tal Carmon, Lev Deych, Lan Yang, Jie Xu

Publications and Research

We report a microfluidic droplet generator which can produce single and compound droplets using a 3D axisymmetric co-flow structure. The design considered for the fabrication of the device integrated a user-friendly and cost-effective 3D printing process. To verify the performance of the device, single and compound emulsions of deionized water and mineral oil were generated and their features such as size, generation frequency, and emulsion structures were successfully characterized. In addition, the generation of bio emulsions such as alginate and collagen aqueous droplets in mineral oil was demonstrated in this study. Overall, the monolithic 3D printed axisymmetric droplet generator could …


Photonics Of Time-Varying Media, Emanuele Galiffi, Romain Tirole, Shixiong Yin, Huanan Li, Stefano Vezzoli, Paloma A. Huidobro, Mário G. Silveirinha, Riccardo Sapienza, Andrea Alù, J. B. Pendry Jan 2022

Photonics Of Time-Varying Media, Emanuele Galiffi, Romain Tirole, Shixiong Yin, Huanan Li, Stefano Vezzoli, Paloma A. Huidobro, Mário G. Silveirinha, Riccardo Sapienza, Andrea Alù, J. B. Pendry

Advanced Science Research Center

Time-varying media have recently emerged as a new paradigm for wave manipulation, due to the synergy between the discovery of highly nonlinear materials, such as epsilon-near-zero materials, and the quest for wave applications, such as magnet-free nonreciprocity, multimode light shaping, and ultrafast switching. In this review, we provide a comprehensive discussion of the recent progress achieved with photonic metamaterials whose properties stem from their modulation in time. We review the basic concepts underpinning temporal switching and its relation with spatial scattering and deploy the resulting insight to review photonic time-crystals and their emergent research avenues, such as topological and non-Hermitian …


Moiré-Driven Topological Transitions And Extremeanisotropy In Elastic Metasurfaces, Simon Yves, Matheus Inguaggiato Nora Nora Rosa, Mohit Gupta, Massimo Ruzzene, Andrea Alù Jan 2022

Moiré-Driven Topological Transitions And Extremeanisotropy In Elastic Metasurfaces, Simon Yves, Matheus Inguaggiato Nora Nora Rosa, Mohit Gupta, Massimo Ruzzene, Andrea Alù

Advanced Science Research Center

The twist angle between a pair of stacked 2D materials has been recently shown to control remarkable phenomena, including the emergence of flat-band superconductivity in twisted graphene bilayers, of higher-order topological phases in twisted moiré superlattices, and of topological polaritons in twisted hyperbolic metasurfaces. These discoveries, at the foundations of the emergent field of twistronics, have so far been mostly limited to explorations in atomically thin condensed matter and photonic systems, with limitations on the degree of control over geometry and twist angle, and inherent challenges in the fabrication of carefully engineered stacked multilayers. Here, this work extends twistronics to …


Emulating Condensed Matter Systems In Classical Wave Metamaterials, Matthew Weiner Sep 2020

Emulating Condensed Matter Systems In Classical Wave Metamaterials, Matthew Weiner

Dissertations, Theses, and Capstone Projects

One of the best tools we have for the edification of physics is the analogy. When we take our classical set of states and dynamical variables in phase space and treat them as vectors and Hermitian operators respectively in Hilbert space through the canonical quantization, we lose out on a lot of the intuition developed with the previous classical physics. With classical physics, through our own experiences and understanding of how systems should behave, we create easy-to-understand analogies: we compare the Bohr model of the atom to the motion of the planets, we compare electrical circuits to the flow of …


Syllabus Ee330 Electromagnetics, Nicholas Madamopoulos Mar 2020

Syllabus Ee330 Electromagnetics, Nicholas Madamopoulos

Open Educational Resources

Concepts covered in the undergraduate electrical engineering class of electromagnetics


Topological Insulating States In Photonics And Acoustics, Xiang Ni May 2019

Topological Insulating States In Photonics And Acoustics, Xiang Ni

Dissertations, Theses, and Capstone Projects

Recent surge of interest in topological insulators, insulating in their interior but conducting at the surfaces or interfaces of different domains, has led to the discovery of a variety of new topological states, and their topological invariants are characterized by numerous approaches in the category of topological band theory. The common features shared by topological insulators include, the topological phase transition occurs if the bulk bandgap is formed due to the symmetries reduction, the topological invariants exist characterizing the global properties of the material and inherently robust to disorder and continuous perturbations irrespective of the local details. Most importantly, these …


Experiential Learning Opportunity (Elo) And Utilization Of Field-And-Data- Based Information Obtained Through The Infusion Of Technology: Highlights On Nasa Stem And Earth Science Curricula, Nazrul I. Khandaker, Matthew Khargie, Shuayb Siddiqu, Sol De Leon, Katina Singh, Newrence Wills, Krishna Mahibar Oct 2017

Experiential Learning Opportunity (Elo) And Utilization Of Field-And-Data- Based Information Obtained Through The Infusion Of Technology: Highlights On Nasa Stem And Earth Science Curricula, Nazrul I. Khandaker, Matthew Khargie, Shuayb Siddiqu, Sol De Leon, Katina Singh, Newrence Wills, Krishna Mahibar

Publications and Research

There is a greater emphasis on hands-on involvement and critical thinking skills in the geosciences and other STEM fields to inspire and engage K- 16 students to value scientific content and enable them to discover the well-documented nature of the fundamental scientific principles needed to explain various earth science and other STEM-related core phenomena. NASA MAA curricula are ideal for engaging K1-16 students in this context, since grade-specific lesson plans open-up a plethora of pedagogically sound and relevant earth science activities. These include earth’s materials and properties, meteorites, robotics, hot air balloon, flight simulation, star gazing, material science, crystal growth, …


Spin Polarisation Oft ̄Tγγproduction At Nlo+Ps With Gosam Interfaced To Madgraph5_Amc@Nlo, Hans Van Deurzen, Rikkert Frederix, Valentin Hirschi, Gionata Luisoni, Pierpaolo Mastrolia, Giovanni Ossola Apr 2016

Spin Polarisation Oft ̄Tγγproduction At Nlo+Ps With Gosam Interfaced To Madgraph5_Amc@Nlo, Hans Van Deurzen, Rikkert Frederix, Valentin Hirschi, Gionata Luisoni, Pierpaolo Mastrolia, Giovanni Ossola

Publications and Research

We present an interface between the multipurpose Monte Carlo toolMadGraph5_aMC@NLOand the automated amplitude generator GoSam. As a first application of this novel framework, we compute the NLO corrections topp→t ̄tHandpp→t ̄tγγmatched to a parton shower. In the phenomenological analyses of these processes, we focus our attention on observables which are sensitive to the polarisation of the top quarks.


Zncdmgse As A Materials Platform For Advanced Photonic Devices: Broadband Quantum Cascade Detectors And Green Semiconductor Disk Lasers, Joel De Jesus Feb 2016

Zncdmgse As A Materials Platform For Advanced Photonic Devices: Broadband Quantum Cascade Detectors And Green Semiconductor Disk Lasers, Joel De Jesus

Dissertations, Theses, and Capstone Projects

The ZnCdMgSe family of II-VI materials has unique and promising characteristics that may be useful in practical applications. For example they can be grown lattice matched to InP substrates with lattice matched bandgaps that span from 2.1 to 3.5 eV, they can be successfully doped n-type, have a large conduction band offset (CBO) with no intervalley scattering present when strained, they have lower average phonon energies, and the InP lattice constant lies in the middle of the ZnSe and CdSe binaries compounds giving room to experiment with tensile and compressive stress. However they have not been studied in detail for …


Electromechanical Magnetization Switching, Eugene M. Chudnovsky, Reem Jaafar Feb 2015

Electromechanical Magnetization Switching, Eugene M. Chudnovsky, Reem Jaafar

Publications and Research

We show that the magnetization of a torsional oscillator that, in addition to the magnetic moment also possesses an electrical polarization, can be switched by the electric field that ignites mechanical oscillations at the frequency comparable to the frequency of the ferromagnetic resonance. The 180° switching arises from the spin-rotation coupling and is not prohibited by the different symmetry of the magnetic moment and the electric field as in the case of a stationary magnet. Analytical equations describing the system have been derived and investigated numerically. Phase diagrams showing the range of parameters required for the switching have been obtained.


Gosam-2.0: A Tool For Automated One-Loop Calculations Within Thestandard Model And Beyond, Gavin Cullen, Hans Van Deurzen, Nicolas Greiner, Gudrun Heinrich, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro, Johannes Schlenk, Johann Felix Von Soden-Fraunhofen, Francesco Tramontano Aug 2014

Gosam-2.0: A Tool For Automated One-Loop Calculations Within Thestandard Model And Beyond, Gavin Cullen, Hans Van Deurzen, Nicolas Greiner, Gudrun Heinrich, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro, Johannes Schlenk, Johann Felix Von Soden-Fraunhofen, Francesco Tramontano

Publications and Research

We present the version 2.0 of the program pack-ageGoSamfor the automated calculation of one-loop ampli-tudes.GoSamis devised to compute one-loop QCD and/orelectroweak corrections to multi-particle processes withinand beyond the Standard Model. The new code containsimprovements in the generation and in the reduction of theamplitudes, performs better in computing time and numer-ical accuracy, and has an extended range of applicability.The extended version of the “Binoth-Les-Houches-Accord”interface to Monte Carlo programs is also implemented. Wegive a detailed description of installation and usage of thecode, and illustrate the new features in dedicated examples.


Advances In Ultrafast Time Resolved Fluorescence Physics For Cancer Detection In Optical Biopsy, R. R. Alfano Mar 2012

Advances In Ultrafast Time Resolved Fluorescence Physics For Cancer Detection In Optical Biopsy, R. R. Alfano

Publications and Research

We discuss the use of time resolved fluorescence spectroscopy to extract fundamental kinetic information on molecular species in tissues. The temporal profiles reveal the lifetime and amplitudes associated with key active molecules distinguishing the local spectral environment of tissues. The femtosecond laser pulses at 310 nm excite the tissue. The emission profile at 340 nm from tryptophan is non-exponential due to the micro-environment. The slow and fast amplitudes and lifetimes of emission profiles reveal that cancer and normal states can be distinguished. Time resolved optical methods offer a new cancer diagnostic modality for the medical community.