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Full-Text Articles in Engineering

Exploring Methods For Recycling Filament Waste In 3d Printing, Max Rios Carballo May 2023

Exploring Methods For Recycling Filament Waste In 3d Printing, Max Rios Carballo

Publications and Research

The goal of the current study is to investigate cutting-edge techniques for recycling filament waste from 3D printing procedures. Appropriate waste management techniques are required to reduce this trash's harmful environmental consequences. The goal of the project is to look at new methods for recycling filament waste in order to minimize disposal and encourage reuse. To acquire data from pertinent papers and research, a thorough literature review methodology was used. The findings show that this issue may be resolved utilizing a variety of recycling techniques, including shredding, melting, and re-extrusion. The type of filament waste and the intended goal will …


The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr. Dec 2022

The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy impacted 443,000 people and caused nearly $19 billion (about $58 per person in the US) worth of damage within New York City. As part of the New York City infrastructure reparation plan, the Living Breakwaters project in Tottenville addressed coastal resilience, allocating $100M of public funds to a series of artificial breakwaters by the southwest coast of Staten Island. Each breakwater is constructed and designed to mitigate water flow in storm events. ECOncrete, a primary element of the breakwater, is a specialty cast cementitious product that is marine organism-friendly that encourages biocalcification and photosynthesis. …


The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr. May 2022

The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy caused nearly $19 billion in damages in New York City including 69,000 residential units across the five boroughs. This disaster precipitated a post-disaster-rebuilding (PDR) project including roughly $4.2 billion in a Community Development Block Grant allocated towards PDR projects. A portion of the grant was used to construct a living breakwater in Tottenville, Staten Island, consisting of a resiliency approach to risk reduction through erosion prevention, wave energy attenuation, and enhancement of ecosystems and social resiliency to improve resistance to storms for the community of Tottenville. The ridges of each breakwater are designed with …


An Archimedes' Screw For Light, Emanuele Galiffi, Paloma A. Huidobro, J. B. Pendry Jan 2022

An Archimedes' Screw For Light, Emanuele Galiffi, Paloma A. Huidobro, J. B. Pendry

Advanced Science Research Center

An Archimedes’ Screw captures water, feeding energy into it by lifting it to a higher level. We introduce the first instance of an optical Archimedes’ Screw, and demonstrate how this system is capable of capturing light, dragging it and amplifying it. We unveil new exact analytic solutions to Maxwell’s Equations for a wide family of chiral space-time media, and show their potential to achieve chirally selective amplification within widely tunable parity-time-broken phases. Our work, which may be readily implemented via pump-probe experiments with circularly polarized beams, opens a new direction in the physics of time-varying media by merging the rising …


Review: Factors Affecting Composite Laminates Against Lightning Strikes, Aaryan Manoj Nair Jul 2021

Review: Factors Affecting Composite Laminates Against Lightning Strikes, Aaryan Manoj Nair

Publications and Research

Lightning strike protection (LSP) have recently been a newly developing field particularly with the emergence of graphene thin film integration into carbon fiber composite structures. This technology has a widespread application in airplanes, wind turbines, and other instruments which are susceptible to frequent lightning strikes. Electrical discharge of the instrument in a safe manner is vital for the safety of the passengers (in the case of flights) as well as the integrity of the aircraft structures because of their specific mechanical and structural properties, which are essential for their functioning. The purpose of the study is to fabricate graphene thin …


Simultaneous Effects Of Rice Husk Silica And Silicon Carbide Whiskers On The Mechanical Properties And Morphology Of Sodium Geopolymer, Akm Rahman, Chirag Shah, Nihkil Gupta Jun 2020

Simultaneous Effects Of Rice Husk Silica And Silicon Carbide Whiskers On The Mechanical Properties And Morphology Of Sodium Geopolymer, Akm Rahman, Chirag Shah, Nihkil Gupta

Publications and Research

The current research is focused on developing a geopolymer binder using rice husk ash–derived silica nanoparticles. Four types of rice husks were collected directly from various rice fields of Bangladesh in order to evaluate the pozzolanic activity and compatibility of the derived rice husk ashes with precursors of sodium-based geopolymers. Silicon carbide whiskers were introduced into sodium-based geopolymers in order to evaluate the response of silicon carbide whiskers to the interfacial bonding and strength of sodium-based geopolymers along with rice husk ashes. Compression, flexural and short beam shear tests were performed to investigate the synergistic effect of rice husk ashes–derived …


Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey Jun 2020

Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey

Publications and Research

La(Fe,Si)13–based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. Many studies have focused on this material family but only in bulk form. In this paper we report on the fabrication of thick films of La(Fe,Si)13, both with and without post-hydriding. These films exhibit magnetic and structural properties comparable to bulk materials. We also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in the cases of …


Fly Ash Based Geopolymer For High Temperature And High Compressive Strength Applications In Aggressive Environment, Aaryan Manoj Nair, Akm S. Rahman May 2020

Fly Ash Based Geopolymer For High Temperature And High Compressive Strength Applications In Aggressive Environment, Aaryan Manoj Nair, Akm S. Rahman

Publications and Research

Geopolymers are the results of geosynthetic reactions between aluminosilicates and strong bases. This results in chemical bonds between aluminum (Al), Silicon (Si)and oxygen (O) composing polymer rings in tetrahedral coordination. These bonds give them widespread useful applications such as high heat bearing ceramics, and base construction material whilst being far more environmentally conscious. The purpose of the experiment is to examine the effect of Silicon Carbide whisker and inorganic glass particles on thermal and mechanical properties of Geopolymers. This study will help understand the effect of various compositions and concentrations of SiO2 in mechanical strength. In this experiment, the …


Optically Pumped Spin Polarization As A Probe Of Many-Body Thermalization, Daniela Pagliero, Pablo R. Zangara, Jacob Henshaw, Ashok Ajoy, Rodolfo H. Acosta, Jeffrey A. Reimer, Alexander Pines, Carlos A. Meriles May 2020

Optically Pumped Spin Polarization As A Probe Of Many-Body Thermalization, Daniela Pagliero, Pablo R. Zangara, Jacob Henshaw, Ashok Ajoy, Rodolfo H. Acosta, Jeffrey A. Reimer, Alexander Pines, Carlos A. Meriles

Publications and Research

Disorder and many body interactions are known to impact transport and thermalization in competing ways, with the dominance of one or the other giving rise to fundamentally different dynamical phases. Here we investigate the spin diffusion dynamics of 13C in diamond, which we dynamically polarize at room temperature via optical spin pumping of engineered color centers. We focus on low-abundance, strongly hyperfine-coupled nuclei, whose role in the polarization transport we expose through the integrated impact of variable radio-frequency excitation on the observable bulk 13C magnetic resonance signal. Unexpectedly, we find good thermal contact throughout the nuclear spin bath, …


Characterization Of A Sagnac Loop Mirror-Based Hybrid Passive Variable Optical Coupler/Attenuator, Simeon Bikorimana, Muhammad A. Ummy, Abdullah Hossain, Richard Lin, Roger Dorsinville Mar 2020

Characterization Of A Sagnac Loop Mirror-Based Hybrid Passive Variable Optical Coupler/Attenuator, Simeon Bikorimana, Muhammad A. Ummy, Abdullah Hossain, Richard Lin, Roger Dorsinville

Publications and Research

The implementation and performance of a unidirectional all-single mode fiber hybrid passive variable optical coupler/attenuator based on a Sagnac loop mirror with a continuous variable coupling ratio using off-the-shelf optical sub-components are discussed. Parameters of two output ports of the unidirectional hybrid passive variable optical coupler/attenuator, such as maximum coupling ratio, insertion loss, excess loss, and wavelength-dependent return loss over the C-band at room temperature are reported. The reflectivity of the Sagnac loop mirror continuously varies from 0.1% to 99.9% by adjusting retarders of a polarization controller. The 3-dB coupling ratio (i.e., 50:50) between the two output ports of the …


Highly Effective Geni Alloy Contact Diffusion Barrier For Bisbte Long-Term Thermal Exposure, Erdong Song, Brian S. Swartzentruber, Chowdary R. Koripella, Julio A. Martinez May 2019

Highly Effective Geni Alloy Contact Diffusion Barrier For Bisbte Long-Term Thermal Exposure, Erdong Song, Brian S. Swartzentruber, Chowdary R. Koripella, Julio A. Martinez

Publications and Research

A GeNi alloy diffusion barrier for contacts on bismuth antimony telluride is proposed. Multiple gold contact diffusion barriers were tested at different thermal aging conditions in air and reducing atmospheres. Among all diffusion barriers, the GeNi alloy barrier shows the best performance for bulk samples with no substantial degradation of the contact resistance, no contact color change, and no change of thermoelectric properties. We observed DAu−GeNi = (9.8 ± 2.7) × 10−20 m2/s within the GeNi alloy barrier, which is 4 times smaller than DAu−BiSbTe. The presence of the initial Ge layer also proves to be effective in reducing nickel …


A Novel Technique For Designing High Power Semiconductor Optical Amplifier (Soa)-Based Tunable Fiber Compound-Ring Lasers Using Low Power Optical Components, Muhammad A. Ummy, Simeon Bikorimana, Roger Dorsinville May 2017

A Novel Technique For Designing High Power Semiconductor Optical Amplifier (Soa)-Based Tunable Fiber Compound-Ring Lasers Using Low Power Optical Components, Muhammad A. Ummy, Simeon Bikorimana, Roger Dorsinville

Publications and Research

A simple, stable and inexpensive dual-output port widely tunable semiconductor optical amplifier (SOA)-based fiber compound-ring laser structure is demonstrated. This unique nested ring cavity enables high optical power to split into different branches where amplification and wavelength selection are achieved by using low-power SOAs and a tunable filter. Furthermore, two Sagnac loop mirrors, which are spliced at the two ends of the compound-ring cavity not only serve as variable reflectors but also channel the optical energy back to the same port without using any high optical power combiner. We propose and discuss how the demonstrated fiber compound-ring laser structure can …


Investigation Of Electric Field–Induced Structural Changes At Fe-Doped Srtio3 Anode Interfaces By Second Harmonic Generation, David Ascienzo, Haochen Yuan, Steven Greenbaum, Thorsten J. Bayer, Russell A. Maier, Jian-Jun Wang, Clive A. Randall, Elizabeth C. Dickey, Haibin Zhao, Yuhang Ren Oct 2016

Investigation Of Electric Field–Induced Structural Changes At Fe-Doped Srtio3 Anode Interfaces By Second Harmonic Generation, David Ascienzo, Haochen Yuan, Steven Greenbaum, Thorsten J. Bayer, Russell A. Maier, Jian-Jun Wang, Clive A. Randall, Elizabeth C. Dickey, Haibin Zhao, Yuhang Ren

Publications and Research

We report on the detection of electric field–induced second harmonic generation (EFISHG) from the anode interfaces of reduced and oxidized Fe-doped SrTiO3 (Fe:STO) single crystals. For the reduced crystal, we observe steady enhancements of the susceptibility components as the imposed dc-voltage increases. The enhancements are attributed to a field-stabilized electrostriction, leading to Fe:Ti-O bond stretching and bending in Fe:Ti-O6 octahedra. For the oxidized crystal, no obvious structural changes are observed below 16 kV/cm. Above 16 kV/cm, a sharp enhancement of the susceptibilities occurs due to local electrostrictive deformations in response to oxygen vacancy migrations away from the anode. Differences between …


Imaging Thermal Conductivity With Nanoscale Resolution Using A Scanning Spin Probe, Abdelghani Laraoui, Halley Aycock-Rizzo, Yang Gao, Xi Lu, Elisa Riedo, Carlos A. Meriles Nov 2015

Imaging Thermal Conductivity With Nanoscale Resolution Using A Scanning Spin Probe, Abdelghani Laraoui, Halley Aycock-Rizzo, Yang Gao, Xi Lu, Elisa Riedo, Carlos A. Meriles

Advanced Science Research Center

The ability to probe nanoscale heat flow in a material is often limited by lack of spatial resolution. Here, we use a diamond-nanocrystal-hosted nitrogen-vacancy centre attached to the apex of a silicon thermal tip as a local temperature sensor. We apply an electrical current to heat up the tip and rely on the nitrogen vacancy to monitor the thermal changes the tip experiences as it is brought into contact with surfaces of varying thermal conductivity. By combining atomic force and confocal microscopy, we image phantom microstructures with nanoscale resolution, and attain excellent agreement between the thermal conductivity and topographic maps. …


Molecular Helices As Electron Acceptors In High-Performance Bulk Heterojunction Solar Cells, Yu Zhong, M. Tuan Trinh, Rongsheng Chen, Geoffrey E. Purdum, Petr P. Khlyabich, Melda Sezen, Seokjoon Oh, Haiming Zhu, Brandon Fowler, Boyuan Zhang, Wei Wang, Chang-Yong Nam, Matthew Y. Sfeir, Charles T. Black, Michael L. Steigerwald, Yueh-Lin Loo, Fay Ng, X.-Y. Zhu, Colin Nuckolls Sep 2015

Molecular Helices As Electron Acceptors In High-Performance Bulk Heterojunction Solar Cells, Yu Zhong, M. Tuan Trinh, Rongsheng Chen, Geoffrey E. Purdum, Petr P. Khlyabich, Melda Sezen, Seokjoon Oh, Haiming Zhu, Brandon Fowler, Boyuan Zhang, Wei Wang, Chang-Yong Nam, Matthew Y. Sfeir, Charles T. Black, Michael L. Steigerwald, Yueh-Lin Loo, Fay Ng, X.-Y. Zhu, Colin Nuckolls

Publications and Research

Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed …


Molecular-Like Hierarchical Self-Assembly Of Monolayers Of Mixtures Of Particles, P. Singh, Md. Shahadat Hossain, S. K. Gurupatham, K. Shah, E. Amah, D. Ju, M. Janjua, S. Nudurupati, I. Fischer Dec 2014

Molecular-Like Hierarchical Self-Assembly Of Monolayers Of Mixtures Of Particles, P. Singh, Md. Shahadat Hossain, S. K. Gurupatham, K. Shah, E. Amah, D. Ju, M. Janjua, S. Nudurupati, I. Fischer

Publications and Research

We present a technique that uses an externally applied electric field to self-assemble monolayers of mixtures of particles into molecular-like hierarchical arrangements on fluid-liquid interfaces. The arrangements consist of composite particles (analogous to molecules) which are arranged in a pattern. The structure of a composite particle depends on factors such as the relative sizes of the particles and their polarizabilities, and the electric field intensity. If the particles sizes differ by a factor of two or more, the composite particle has a larger particle at its core and several smaller particles form a ring around it. The number of particles …


Performance Analysis Of A Hybrid Raman Optical Parametric Amplifier In The O- And E-Bands For Cwdm Pons, Sasanthi Peiris, Nicolas Madamopoulos, Neophytos A. Antoniades, Dwight Richards, Roger Dorsinville Dec 2014

Performance Analysis Of A Hybrid Raman Optical Parametric Amplifier In The O- And E-Bands For Cwdm Pons, Sasanthi Peiris, Nicolas Madamopoulos, Neophytos A. Antoniades, Dwight Richards, Roger Dorsinville

Publications and Research

We describe a hybrid Raman-optical parametric amplifier (HROPA) operating at the O- and E-bands and designed for coarse wavelength division multiplexed (CWDM) passive optical networks (PONs). We present the mathematical model and simulation results for the optimization of this HROPA design. Our analysis shows that separating the two amplification processes allows for optimization of each one separately, e.g., proper selection of pump optical powers and wavelengths to achieve maximum gain bandwidth and low gain ripple. Furthermore, we show that the proper design of optical filters incorporated in the HROPA architecture can suppress idlers generated during the OPA process, as well …


Fabrication Of Size-Tunable Metallic Nanoparticles Using Plasmid Dna As A Biomolecular Reactor, Jacopo Samson, Irene Piscopo, Alex Yampolski, Patrick Nahirney, Andrea Parpas, Amit Aggarwal, Raihan Saleh, Charles Michael Drain Oct 2011

Fabrication Of Size-Tunable Metallic Nanoparticles Using Plasmid Dna As A Biomolecular Reactor, Jacopo Samson, Irene Piscopo, Alex Yampolski, Patrick Nahirney, Andrea Parpas, Amit Aggarwal, Raihan Saleh, Charles Michael Drain

Publications and Research

Plasmid DNA can be used as a template to yield gold, palladium, silver, and chromium nanoparticles of different sizes based on variations in incubation time at 70 °C with gold phosphine complexes, with the acetates of silver or palladium, or chromium acetylacetonate. The employment of mild synthetic conditions, minimal procedural steps, and aqueous solvents makes this method environmentally greener and ensures general feasibility. The use of plasmids exploits the capabilities of the biotechnology industry as a source of nanoreactor materials.