Engineering Commons^™

Design, Fabrication, And Physical Properties Analysis Of Laminated Low-E Coated Glass For Retrofit Window Solutions, Mohammad Nur-E-Alam, Mikhail Vasiliev, Boon Kar Yap, Mohammad Aminul Islam, Yaseer Fouad, Tiong Sieh Kiong

Research outputs 2022 to 2026

The ever-growing demand for improved energy efficiency in buildings has stimulated a stream of research focused on innovative retrofit energy solutions. Laminated low emissivity (Low-E) type coated glass components can be used in retrofitting window systems for enhancing energy savings provided by the insulating properties of glass laminates containing these heat-mirror-type coatings. In particular, custom-designed double-silver low-E coatings embedded into the laminate structure (directly facing the polymer interlayers during and after the lamination) are of interest due to being protected from environmental exposure, enabling easy component transportation, storage, and window retrofits. In this study, we provide some details on the …

Residual Optical Absorption From Native Defects In Cdsip2 Crystals, Timothy D. Gustafson, Nancy C. Giles, Elizabeth M. Scherrer, Kevin T. Zawilski, Peter G. Schunemann, Kent L. Averett, Jonathan E. Slagle, Larry E. Halliburton

Faculty Publications

CdSiP₂ crystals are used in optical parametric oscillators to produce tunable output in the mid-infrared. As expected, the performance of the OPOs is adversely affected by residual optical absorption from native defects that are unintentionally present in the crystals. Electron paramagnetic resonance (EPR) identifies these native defects. Singly ionized silicon vacancies (V^-_Si) are responsible for broad optical absorption bands peaking near 800, 1033, and 1907 nm. A fourth absorption band, peaking near 630 nm, does not involve silicon vacancies. Exposure to 1064 nm light when the temperature of the CdSiP₂ crystal is near 80K converts …

Direct Spectroscopic Observation Of Cross-Plane Heat Transfer In A Two-Dimensional Van Der Waals Heterostructure, Du Chen, Matthieu Fortin-Deschênes, Yuchen Lou, Huiju Lee, Kenji Watanabe, Takaaki Taniguchi, Fengnian Xia, Peijun Guo, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

Two-dimensional (2D) transition metal chalcogenides (TMDs) have drawn significant attention in recent years due to their extraordinary optical and electronic properties. As heat transfer plays an important role in device performance, various methods such as optothermal Raman spectroscopy and time-domain thermoreflectance have been developed to measure the thermal conductivity and interfacial thermal conductance in 2D van der Waals (vdW) heterostructures. Here, we employ the vibrational-pump-visible-probe (VPVP) spectroscopy to directly visualize the heat transfer process in a heterostructure of multilayer h-BN and monolayer WS2. Following an impulsive vibrational excitation of h-BN in the mid-infrared, we probe the heat transfer …

Enhanced Internal Coating Structure And Light Reflectance Of Coated Papers: A Sludge Valorization Process, Bilge N. Altay, Anamika Huq, Burak Aksoy, Richard Hailstone, Muslum Demir, Cem Aydemir, Arif Karademir, Scott Williams

Articles

Paper mill sludge (PMS) is a high-volume waste of the pulppapermaking industry, containing cellulose fibers. This paper introduces cellulose nanofibers extracted from PMS (CNFsPMS) and their application in paper coatings using a wire-wound coating method to enhance internal and optical properties of paper. Three factors were investigated: (i) CNFsPMS amount, (ii) number of layers, and (iii) surface treatment via a 4 × 2 × 2 factorial design. The experimental responses were tracked by fundamentally important internal properties including porosity, air permeability, thickness, roughness, and optical properties of brightness, gloss, and CIE L*a*b* color coordination. The results showed that CNFPMS enhances …

Effect Of Substituent Location On The Relationship Between The Transition Dipole Moments, Difference Static Dipole, And Hydrophobicity In Squaraine Dyes For Quantum Information Devices, Maia Ketteridge, Austin Biaggne, Ryan Rau, German Barcenas, Olga A. Mass, William B. Knowlton, Bernard Yurke, Lan Li

Materials Science and Engineering Faculty Publications and Presentations

Aggregates of organic dyes that exhibit excitonic coupling have a wide array of applications, including medical imaging, organic photovoltaics, and quantum information devices. The optical properties of a dye monomer, as a basis of dye aggregate, can be modified to strengthen excitonic coupling. Squaraine (SQ) dyes are attractive for those applications due to their strong absorbance peak in the visible range. While the effects of substituent types on the optical properties of SQ dyes have been previously examined, the effects of various substituent locations have not yet been investigated. In this study, density functional theory (DFT) and time-dependent density functional …

Microstructural And Optical Properties Of Mgal2o4 Spinel: Effects Of Mechanical Activation, Y2o3 And Graphene Additions, Nina Obradovic, William Fahrenholtz, Cole Corlett, Suzana Filipovic, Marko Nikolic, Bojan A. Marinkovic, Simone Failla, Diletta Sciti, Daniele Di Rosa, Elisa Sani

Materials Science and Engineering Faculty Research & Creative Works

Magnesium Aluminate and Other Alumina-Based Spinels Attract Attention Due to their High Hardness, High Mechanical Strength, and Low Dielectric Constant. MgAl₂O₄ Was Produced by a Solid-State Reaction between MgO and Α-Al₂O₃ Powders. Mechanical Activation for 30 Min in a Planetary Ball Mill Was Used to Increase the Reactivity of Powders. Yttrium Oxide and Graphene Were Added to Prevent Abnormal Grain Growth during Sintering. Samples Were Sintered by Hot Pressing under Vacuum at 1450◦C. Phase Composition and Microstructure of Sintered Specimens Were Characterized by X-Ray Powder Diffraction and Scanning Electron Microscopy. Rietveld Analysis Revealed 100% …

Mechanical Properties, Translucency, And Low Temperature Degradation (Ltd) Of Yttria (3–6 Mol%) Stabilized Zirconia, R. Sharon Uwanyuze, Sulekha Ramesh, Mark K. King, Nathaniel Lawson, Manoj K. Mahapatra

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties (hardness and biaxial flexural strength), optical properties (translucency and gloss), and low temperature degradation (LTD) of 3–6 mol% yttria stabilized zirconia have been investigated. The specimens were prepared by conventional solid-state sintering at 1400 °C. The mechanical and optical properties were evaluated for sintered and polished specimens. X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used, respectively, for structural and microstructural investigation. LTD was determined by XRD analysis of the samples aged in a hydrothermal autoclave at 134 °C for 5–108 h. The mechanical and optical properties are found to be microstructure sensitive. The LTD, due …

First-Principles Density Functional Theory Studies On Perovskite Materials, Aneer Lamichhane

Dissertations

Perovskites are a family of materials with a diverse combination of different elements. As a consequence, they exhibit numerous functionalities such as pyroelectric, piezoelectric, ferroelectric, and ferromagnetic with applications in photovoltaic cells, LEDs, superconductivity, colossal magneto-resistance, and topological insulators. After 2009, perovskites have gained notoriety as suitable materials for solar cells and alternative candidates to silicon-based conventional solar cells. Generally, oxide perovskites exhibit good dielectric properties, halide perovskites display good photonic qualities, and chalcogenide perovskites are used in applications in solid-state lighting, sensing, and energy harvesting. In this dissertation, various types of perovskites ranging from oxide to halide are investigated …

Reflection And Transmission Of Electromagnetic Pulses At A Planar Dielectric Interface: Theory And Quantum Lattice Simulations, Abhay K. Ram, George Vahala, Linda Vahala, Min Soe

Electrical & Computer Engineering Faculty Publications

There is considerable interest in the application of quantum information science to advance computations in plasma physics. A particular point of curiosity is whether it is possible to take advantage of quantum computers to speed up numerical simulations relative to conventional computers. Many of the topics in fusion plasma physics are classical in nature. In order to implement them on quantum computers, it will require couching a classical problem in the language of quantum mechanics. Electromagnetic waves are routinely used in fusion experiments to heat a plasma or to generate currents in the plasma. The propagation of electromagnetic waves is …

Tunable Luminescence Of Rare Earth Doped Nanophosphors Via Adaptive Optical Properties Of Transition Metals, Pragathi Darapaneni

LSU Doctoral Dissertations

Over the past decades, the development of light-emitting diodes (LEDs) to produce a wide range of wavelengths has revolutionized the solid-state lighting industry due to their higher energy efficiency and operational lifetimes. These LEDs employ rare earth (RE) doped phosphors due to their stable emission wavelengths which can be amplified when sensitized by other RE dopants (Yb, Ce) or shell layer passivation. However, there has been a push to replace the RE elements in LEDs due to increased socioeconomic issues. One proposed alternative, transition metal (TM) dopants, is typically avoided due to their susceptibility to the local crystal environment resulting …

Optical Properties Of Polymers And Their Applications, Samiha Hossain

Theses

The last decade has witnessed explosive growth in the world of photoactive polymers for a variety of applications in several sectors of the global economy. The need for efficient, reliable, and low-cost data acquisition, storage, processing, transmission, and display technologies has made it necessary for research aimed at addressing these needs. Recent accomplishments in this materials area represent exciting opportunities for major innovations in various fields. However, further work needs to be done to transfer the technology from fundamental R&D to manufacturing. The goal of this study is to provide a better understanding of the optical properties of polymers and …

Light Scattering Measured With Spatial Frequency Domain Imaging Can Predict Stromal Versus Epithelial Proportions In Surgically Resected Breast Tissue, David M. Mcclatchy, Elizabeth J. Rizzo, Wendy A. Wells, Candice C. Black, Keith D. Paulsen, Stephen C. Kanick, Brian W. Pogue

Dartmouth Scholarship

This study aims to determine if light scatter parameters measured with spatial frequency domain imaging (SFDI) can accurately predict stromal, epithelial, and adipose fractions in freshly resected, unstained human breast specimens. An explicit model was developed to predict stromal, epithelial, and adipose fractions as a function of light scattering parameters, which was validated against a quantitative analysis of digitized histology slides for N  =  31 specimens using leave-one-out cross-fold validation. Specimen mean stromal, epithelial, and adipose volume fractions predicted from light scattering parameters strongly correlated with those calculated from digitized histology slides (r  =  0.90, 0.77, and 0.91, respectively, p-value× …

Silicon Based Uncooled Microbolometer, Asahel Banobre

Dissertations

During the last decade, uncooled microbolometer infrared detectors have attracted the attention of military and civilian infrared detection and imaging industry due to their significant advantages. In actuality, infrared imaging systems play a critical role in sectors such as thermography (predictive maintenance and building inspection), commercial and civilian applications (vision automotive, surveillance, navigation and fire-fighting), and defense industry (thermal weapon sight, soldier vision and vehicle vision enhancer). Compared with the cryogenically cooled infrared photon detectors, uncooled infrared imaging technology offers advantages such as operation at room temperature, light weight and size, reduced power consumption, easy integration with read-out electronics and …

Optimal Wavelength Selection For Optical Spectroscopy Of Hemoglobin And Water Within A Simulated Light-Scattering Tissue, Mikael Marois, Stephen L. Jacques, Keith D. Paulsen

Dartmouth Scholarship

An algorithm that selects optimal wavelengths for spectral fitting of diffuse light reflectance spectra using a nonnegative least squares method is presented. Oxyhemoglobin, deoxyhemoglobin, and water are considered representative absorbers, but the approach is not constrained or limited by absorber selection provided native basis spectra are available. The method removes wavelengths iteratively from a scattering-modulated absorption matrix by maximizing the product of its singular values and offers considerable improvements over previously published wavelength selection schemes. Resulting wavelength selections are valid for a broad range of optical properties and yield lower RMS errors than other wavelength combinations. The method is easily …

Performance Assessment Of Diffuse Optical Spectroscopic Imaging Instruments In A 2-Year Multicenter Breast Cancer Trial, Anais Leproux, Thomas D.O. Sullivan, Albert E. Cerussi, Amanda Durkin, Brian Hill, Nola M. Hylton, Arjun G. Yodh, Stefan A. Carp, David A. Boas, Shudong Jiang, Keith D. Paulsen, Brian W. Pogue, Darren M. Roblyr, Wei T. Yang, Bruce J. Tromberg

Dartmouth Scholarship

We present a framework for characterizing the performance of an experimental imaging technology, diffuse optical spectroscopic imaging (DOSI), in a 2-year multicenter American College of Radiology Imaging Network (ACRIN) breast cancer study (ACRIN-6691). DOSI instruments combine broadband frequency-domain photon migration with time-independent near-infrared (650 to 1000 nm) spectroscopy to measure tissue absorption and reduced scattering spectra and tissue hemoglobin, water, and lipid composition. The goal of ACRIN-6691 was to test the effectiveness of optically derived imaging endpoints in predicting the final pathologic response of neoadjuvant chemotherapy (NAC). Sixty patients were enrolled over a 2-year period at participating sites and received …

Impact Of Wastewater Strength And Photocatalyst Loading On Decolourization Of Acid Orange 7 By Co-Doped Tio2, Erick Butler, Oliver Mulamba, Yung Tse Hung, Ching Cheng Chen, Yen Pei Fu

Civil and Environmental Engineering Faculty Publications

© 2017, Chemical Publishing Co. All rights reserved. Heterogeneous photocatalysis has proved to be a successful method for the degradation of water pollutants. In this work, the photocatalytic decolourization of acid orange 7 was performed by cobalt-doped titanium dioxide (Co-doped TiO2). The Co-doped TiO2 was synthesized and characterized using X-ray diffraction, scanning electron microscopy, energy diffraction spectroscopy, UV-visible reflective dispersion spectroscopy and adsorption of nitrogen gas. The acid orange 7 was prepared as a synthetic textile wastewater at three initial concentrations (24, 34 and 44 mg/L) with three photocatalyst loadings (0.025 g, 0.050, 0.1 g/100 mL acid orange 7). Results …

A New Formulation Of Time Boundary Integral Equation For Acoustic Wave Scattering In The Presence Of A Uniform Mean Flow, Fang Q. Hu, Michelle E. Pizzo, Douglas M. Nark

Mathematics & Statistics Faculty Publications

It has been well-known that under the assumption of a constant uniform mean flow, the acoustic wave propagation equation can be formulated as a boundary integral equation, in both the time domain and the frequency domain. Compared with solving partial differential equations, numerical methods based on the boundary integral equation have the advantage of a reduced spatial dimension and, hence, requiring only a surface mesh. However, the constant uniform mean flow assumption, while convenient for formulating the integral equation, does not satisfy the solid wall boundary condition wherever the body surface is not aligned with the uniform mean flow. In …

Photoluminescence Of Lead Sulfide Quantum Dots Of Different Sizes In A Nanoporous Silicate Glass Matrix, Aleksandr P. Litvin, Anton Babaev, Peter Parfenov, Elena Ushakova, Mikhail Baranov, Olga Andreeva, Kevin Berwick, Anatoly Fedorov, Alexander Baranov

Articles

The optical properties of lead sulfide quantum dots (QDs) of different sizes embedded in a nanoporous silicate glass matrix (NSM) are investigated by steady-state and transient photoluminescence spectroscopy. The use of this matrix allows the fabrication of samples with reproducible optical characteristics, for both isolated and close-packed QDs. Low-temperature PL analysis of isolated QDs with sizes of 3.7 and 4.5 nm shows that the coefficient of temperature shift of the PL position changes sign with reducing QD size because of size-dependent contributions from thermal expansion, mechanical strain, and electron–phonon coupling. The PL intensity is determined by size-dependent splitting of the …

Plasmonic Devices Based On Transparent Conducting Oxides For Near Infrared Applications, Kim Jongbum

Open Access Dissertations

In the past decade, there have been many breakthroughs in the field of plasmonics and nanophotonics that have enabled optical devices with unprecedented functionalities. Even though remarkable demonstration of at photonic devices has been reported, constituent materials are limited to the noble metals such as gold (Au) and silver (Ag) due to their abundance of free electrons which enable the support of plasmon resonances in the visible range. With the strong demand for extension of the optical range of plasmonic applications, it is now a necessity to explore and develop alternative materials which can overcome intrinsic issues of noble metals …

Statistical Mechanical Treatments Of The Optical Properties Of Cadmium Selenide Quantum Dots, Amogh Srihari

Dissertations - ALL

Semiconductors that exist in the nanoscale are referred to as Quantum Dots (QDs). This distinction is made because in the nanoscale, semiconductors behave much differently compared to their bulk counterparts. QDs possess band gaps that change based on their size and this unique property enables them to emit different colors, rendering them useful in a number of applications. QDs are widely used in LED technology and are becoming commonplace in biological applications involving in-vivo imaging. Efforts have gone into making QDs viable for photovoltaic applications as well. Although a lot is understood about the effects of size and shape on …

Modeling And Simulation Of Optical Properties Of Noble Metals Triangular Nanoprisms, Soad Zahir Alsheheri

Electronic Theses and Dissertations

Gold and silver has gained huge attention across the scientific community for its applications arising from its plasmonic properties. The optical properties achieved by these materials via excitation of plasmons is very unique to these materials and used as diagnostic and therapeutic agents in the field of medicine, and as sensors in a gamut of disciplines such as energy and environmental protection to name a few. Surface plasmon resonance (SPR) properties of the gold and silver are size and shape dependent. Of the various shapes reported in literature, triangular nanoprisms has tunable optical properties in the visible and near IR …

Simulation Of Electronic And Optical Properties Of Graphene, Biao Leng

Theses

Graphene is a recently discovered two-dimensional crystal. Due to its excellent electronic properties, transport properties, optical properties, and many other features, it has tremendous potential for applications in many areas. This thesis discusses the structure and properties of graphene using several different models of graphene and carries out detailed theoretical studies and calculations of its electronic and optical properties. Using two modules of Materials Studio, CASTAP and Doml3, four graphene models have been constructed. Their electronic and optical properties have also been calculated via these two modules. By comparing the results of calculations with experimental results and the literature, the …

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 and Ag-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while the Cu-doped …

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photocatalytic Applications, Haya Abdel Ra'ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO₂ nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO₂ nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO₂ nanomaterials. In this work, we have prepared Cu-doped TiO₂ nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO₂ catalyst was prepared by the sol-gel method while …

Spotlight On Available Optical Properties And Models Of Nanofluids: A Review

Faculty of Engineering University of Malaya

Optical characteristics besides unique thermo-physical properties of nanoparticles have encouraged researchers to use nanofluids in solar energy collectors or reservoirs as electromagnetic wave absorbing media. Recently, different analyses and approaches have been proposed by researchers. However, the appropriate electro-magnetic phenomenon of nanofluids is not established till date because of the complex dependence between nanoparticles and base fluids. In this work, optical properties of nanofluids are discussed on the basis of published data; mostly used models are presented along with their limitations and applications. (C) 2014 Elsevier Ltd. All rights reserved. Link to Full-Text Articles : http://www.sciencedirect.com/science/article/pii/S1364032114009411

Optical Properties Of Strain-Engineered Multilayer Si/Sige Nanostructures, Selina Akter Mala

Dissertations

The long carrier radiative lifetimes in indirect band gap semiconductors such as crystalline Si (c-Si) and Ge impede the development of efficient light-emitting devices and lasers. Multilayer Si/SiGe nanostructures are considered to be the strong candidates for efficient and high-speed optoelectronic devices integrated into CMOS platforms. Since c-Si and Ge have a considerable lattice mismatch of ~ 4.2%, Si/Si_1-xGe_x(x < 0.5) nanostructures in the form of nano-layers (NLs) or cluster multilayers (CMs) modify the band structure and create non-uniform strain distribution. Engineering of Si/Si_1-xGe_xnanostructures with the predicted composition and interface abruptness, which controls spatial separation between electrons and holes and carrier radiative recombination rate, is critical in producing the desired fast and efficient photoluminescence …

Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf

Faculty Publications

By sorting through hundreds of globally stable Si₁₂C₁₂ isomers using a potential surface search and using simulated annealing, we have identified low-energy structures. Unlike isomers knit together by Si–C bonds, the lowest energy isomers have segregated carbon and silicon regions that maximize stronger C–C bonding. Positing that charge separation between the carbon and silicon regions would produce interesting optical absorption in these cluster molecules, we used time-dependent density functional theory to compare the calculated optical properties of four isomers representing structural classes having different types of silicon and carbon segregation regions. Absorptions involving charge transfer between segregated …

Design Optimization And Optical Characterization Of A High Temperature Solar Receiver, Samia Afrin

Open Access Theses & Dissertations

Concentrated solar power (CSP) is a fast forwarding technology in power generation sector because of its' competitive price, abundance in nature and the most important fact is its' energy storage capability. Among the four types of available CSP technology, central receiver has more potential concerning with high temperature, power block efficiency and levelized cost of energy (LCOE). Other than conventional type of receiver design, the concept of this work is very particular in a sense of its design novelty.

National Renewable Energy Laboratory (NREL) come up with a new concept of high temperature solar receiver called near black body (NBB) …

Formation Of Circular Optical Membranes Under Free-Form Yielding, Christopher Tuan, David White

Christopher Y. Tuan

High‐quality optical reflector surfaces are attainable with the use of pressure‐formed membranes. The formation technique involves gradual application of fluid pressure on initially flat, simply supported circular membranes until a desirable center deflection is reached. After the fluid is removed, a uniform pressure is subsequently applied to offset the surface slope error. Empirical testing of membrane‐forming technique was conducted at two scales to define the critical process variables that controlled material yielding. Aluminum membranes with 54‐in. (1.4‐m) diameter were constructed for the smaller scale and with 144‐in. (3.7‐m) diameter for the larger scale. The experiments were carried out with the …

Nanometric Structure-Property Relationship In Hafnium Oxide Thin Films Made By Sputter-Deposition, Mirella Vargas

Open Access Theses & Dissertations

Hafnium oxide (HfO2) is technologically an important material, which exhibits a unique set of properties such as a high dielectric constant (k~25) and wide band gap (~5.7 eV) which make this material attractive in the fields of microelectronics and optoelectronics. HfO2 has become the leading candidate to replace SiO2 dielectrics in gate oxides due to a higher permittivity and reportedly lower electron tunneling effects. HfO2 exhibits various polymorphs; the thermodynamic stability and phase existence depends on the temperature and pressure conditions. In addition, the controlled growth and manipulation of specific HfO2 crystal structures at the nanoscale dimensions is the driving …