Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 68731 - 68760 of 294409

Full-Text Articles in Physical Sciences and Mathematics

A Unifying Framework For Parallel And Distributed Processing In R Using Futures, Henrik Bengtsson Dec 2021

A Unifying Framework For Parallel And Distributed Processing In R Using Futures, Henrik Bengtsson

The R Journal

A future is a programming construct designed for concurrent and asynchronous evaluation of code, making it particularly useful for parallel processing. The future package implements the Future API for programming with futures in R. This minimal API provides sufficient constructs for implementing parallel versions of well-established, high-level map-reduce APIs. The future ecosystem supports exception handling, output and condition relaying, parallel random number generation, and automatic identification of globals lowering the threshold to parallelize code. The Future API bridges parallel frontends with parallel backends, following the philosophy that end-users are the ones who choose the parallel backend while the developer focuses …

Go to article

Compmodels: A Suite Of Computer Model Test Functions For Bayesian Optimization, Tony Pourmohamad Dec 2021

Compmodels: A Suite Of Computer Model Test Functions For Bayesian Optimization, Tony Pourmohamad

The R Journal

The CompModels package for R provides a suite of computer model test functions that can be used for computer model prediction/emulation, uncertainty quantification, and calibration. Moreover, the CompModels package is especially well suited for the sequential optimization of computer models. The package is a mix of real-world physics problems, known mathematical functions, and black-box functions that have been converted into computer models with the goal of Bayesian (i.e., sequential) optimization in mind. Likewise, the package contains computer models that represent either the constrained or unconstrained optimization case, each with varying levels of difficulty. In this paper, we illustrate the use …

Go to article

Generalized Linear Randomized Response Modeling Using Glmmrr, Jean-Paul Fox, Konrad Klotzke, Duco Veen Dec 2021

Generalized Linear Randomized Response Modeling Using Glmmrr, Jean-Paul Fox, Konrad Klotzke, Duco Veen

The R Journal

Randomized response (RR) designs are used to collect response data about sensitive behaviors (e.g., criminal behavior, sexual desires). The modeling of RR data is more complex since it requires a description of the RR process. For the class of generalized linear mixed models (GLMMs), the RR process can be represented by an adjusted link function, which relates the expected RR to the linear predictor for most common RR designs. The package GLMMRR includes modified link functions for four different cumulative distributions (i.e., logistic, cumulative normal, Gumbel, Cauchy) for GLMs and GLMMs, where the package lme4 facilitates ML and REML estimation. …

Go to article

An R Package For Non-Normal Multivariate Distributions: Simulation And Probability Calculations From Multivariate Lomax (Pareto Type Ii) And Other Related Distributions, Zhixin Lun, Ravindra Khattree Dec 2021

An R Package For Non-Normal Multivariate Distributions: Simulation And Probability Calculations From Multivariate Lomax (Pareto Type Ii) And Other Related Distributions, Zhixin Lun, Ravindra Khattree

The R Journal

Convenient and easy-to-use programs are readily available in R to simulate data from and probability calculations for several common multivariate distributions such as normal and t. However, functions for doing so from other less common multivariate distributions, especially those which are asymmetric, are not as readily available, either in R or otherwise. We introduce the R package NonNorMvtDist to generate random numbers from multivariate Lomax distribution, which constitutes a very flexible family of skewed multivariate distributions. Further, by applying certain useful properties of multivariate Lomax distribution, multivariate cases of generalized Lomax, Mardia’s Pareto of Type I, Logistic, Burr, Cook-Johnson’s uniform, …

Go to article

Gpu-Based Monte Carlo Applications In Radiation Medicine, Youfang Lai Dec 2021

Gpu-Based Monte Carlo Applications In Radiation Medicine, Youfang Lai

Physics Dissertations - Archive

Radiation can be used to image tumor site or kill tumor cells noninvasively, playing an important role in tumor diagnosis and treatment. Because of the increasing burden that cancer brings to the society, there always exists the demand of improving imaging resolution and contrast and improving radiation conformity for therapy. This depends on not only the advances of techniques, but, probably more importantly, the accurate and efficient modelling of radiation transport, enabling research on proof-of-concept for new tech and more complicated physics and chemical process in a quantitative way. Monte Carlo (MC) simulation method has been extensively used in medical …

Go to article

Understanding Students’ Global Interdependence In Science Instruction, Walter S. Smith Dec 2021

Understanding Students’ Global Interdependence In Science Instruction, Walter S. Smith

Journal of Global Education and Research

Multiple American educational organizations such as the National Education Association, Association for Supervision and Curriculum Development, and the Council of Chief State School Officers have advocated for globalizing the K-12 curriculum. The National Science Teaching Association (NSTA) in a position statement on international education and the Next Generation Science Standards have produced goals and standards for internationalizing the science curriculum by addressing topics such as climate change, environment, and disease that cross borders. In contrast to those pronouncements on the curriculum, this article views global science education through an instructional lens that focuses on a students’ global interdependence in science …

Go to article

Energy Dissipation During Geomagnetic Storms, Fatemeh Bagheri Dec 2021

Energy Dissipation During Geomagnetic Storms, Fatemeh Bagheri

Physics Dissertations - Archive

Some fraction of the solar wind energy is transferred to the Earth magnetosphere and ionosphere. Sometimes this transfer of energy is exceptionally large, producing a magnetic storm. Storms occur when the Interplanetary Magnetic Field (IMF) turns southward and remains southward for an extended period of time. During the main phase of many magnetic storms, the solar wind Mach number is low, and IMF magnitude is large. Under these conditions, the ionospheric potential saturates, and it becomes relatively insensitive to further increases in the IMF magnitude. On the other hand, the dayside merging rate and the potential become sensitive to the …

Go to article

The Arecibo Observatory As An Instrument For Investigating Orbital Debris, James Isaiah Murray Dec 2021

The Arecibo Observatory As An Instrument For Investigating Orbital Debris, James Isaiah Murray

Physics Dissertations - Archive

In this dissertation, the Arecibo Observatory, both past and future, as an instrument for investigating orbital debris is investigated. For over three decades, models of the orbital debris environment in low Earth orbit (LEO) have been developed to assess the risk posed by orbital debris to spacecraft. While terrestrial radar measures debris 3 mm and larger and in-situ measurements provide data for debris smaller than 1 mm, no good data sources exist for debris between 1 mm and 3 mm in size. This results in large variations between competing orbital debris models. It also happens to be the size regime …

Go to article

Electronic And Magnetic Properties Of Metal Doped Silicon-Carbide Fullerene-Type Nanostructures, Hussain Jabreel Alathlawi Dec 2021

Electronic And Magnetic Properties Of Metal Doped Silicon-Carbide Fullerene-Type Nanostructures, Hussain Jabreel Alathlawi

Physics Dissertations - Archive

Silicon carbide (SiC) is a technologically significant material. A recent report on the abundance of C60 fullerenes in interstellar space, along with the presence of SiC precursors, sparked interest in potentially similar SiC nanostructures. C60 and C70 fullerenes were found experimentally and are an exceptionally stable form of carbon. As Si and C have similar valence electron configurations, it has been long envisioned that Si and SiC could also form similar fullerene-type structures. In this dissertation, Si30C30 fullerene-derived clusters were studied from the first principles theory, starting from an ideal Si60 fullerene template with various arrangements of silicon and carbon …

Go to article

Nonlinear Mode Coupling Coefficients In Extrasolar Hot Jupiter Systems With Non-Solar Type Host Stars, Niyousha Davachi Dec 2021

Nonlinear Mode Coupling Coefficients In Extrasolar Hot Jupiter Systems With Non-Solar Type Host Stars, Niyousha Davachi

Physics Theses - Archive

Short period planets tidally excite internal gravity modes within their host star. These excited modes, known collectively as the dynamical tide, dissipate orbital energy and cause the planet’s orbit to decay. In hot Jupiter systems, resonantly excited gmodes are driven to such large amplitudes in the stellar core that they nonlinearly excite a sea of secondary modes. These secondary modes can greatly enhance the efficiency of tidal dissipation compared to linear theory predictions and thus significantly increase the rate of orbital decay. In this thesis we calculate the three-mode coupling coefficients between the excited g-modes of hot Jupiter host stars. …

Go to article

Headspace-Solid Phase Micro Extraction – Gas Chromatography – Mass Spectrometry (Hs-Spme-Gc-Ms) Analysis For Oak Barrel Flavor Compounds In Whiskey, Hailey F. Jarzynka Dec 2021

Headspace-Solid Phase Micro Extraction – Gas Chromatography – Mass Spectrometry (Hs-Spme-Gc-Ms) Analysis For Oak Barrel Flavor Compounds In Whiskey, Hailey F. Jarzynka

Chemistry & Biochemistry Theses - Archive

This study presents a method to simultaneously detect both fault compounds and oak barrel flavor compounds in whiskey using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). A major contaminant in whiskey is geosmin and an array of oak barrel compounds includes 2-methoxy-4-methylphenol, 5-methylfurfural, guaiacol, trans-whiskey lactone, 2-methoxy-4-vinylphenol, 4-ethylguaiacol, eugenol, vanillin, and 4-ethylphenol. Geosmin is a fault compound that produces a musty or moldy taste to the whiskey and the other compounds originate from the barrels in which the whiskey is aged in and transfer to the whiskey in the aging process. Each compound was quantitated and 15 different whiskies were compared …

Go to article

Soil Structure And Soil Moisture Dynamics Inferred From Time-Lapse Electrical Resistivity Tomography, Travis Nielson, John Bradford, Jen Pierce, Mark Seyfried Dec 2021

Soil Structure And Soil Moisture Dynamics Inferred From Time-Lapse Electrical Resistivity Tomography, Travis Nielson, John Bradford, Jen Pierce, Mark Seyfried

Geosciences Faculty Publications and Presentations

The semi-arid sagebrush steppe in the western United States faces pressures from the agriculture industry, recreation use, invasive grasses, and a changing climate. A key to facilitating the healthy management of this ecosystem is understanding the distribution and behavior of soil moisture in the vadose zone in both natural and agricultural settings. Within unsaturated environments, soil moisture is spatially and temporally heterogeneous, and changes in porosity and permeability within arid soils complicate characterization of soil hydrologic properties. Importantly, accumulations of ‘caliche’ or pedogenic calcium carbonate in arid soils can greatly limit permeability; however, observing the role that caliche plays in …

Go to article

Comparison Of Different Analytical Strategies For Classifying Invasive Wetland Vegetation In Imagery From Unpiloted Aerial Systems (Uas), Louis Will Jochems, Jodi Brandt, Andrew Monks, Megan Cattau, Nicholas Kolarik, Jason Tallant, Shane Lishawa Dec 2021

Comparison Of Different Analytical Strategies For Classifying Invasive Wetland Vegetation In Imagery From Unpiloted Aerial Systems (Uas), Louis Will Jochems, Jodi Brandt, Andrew Monks, Megan Cattau, Nicholas Kolarik, Jason Tallant, Shane Lishawa

Human-Environment Systems Research Center Faculty Publications and Presentations

Detecting newly established invasive plants is key to prevent further spread. Traditional field surveys are challenging and often insufficient to identify the presence and extent of invasions. This is particularly true for wetland ecosystems because of difficult access, and because floating and submergent plants may go undetected in the understory of emergent plants. Unpiloted aerial systems (UAS) have the potential to revolutionize how we monitor invasive vegetation in wetlands, but key components of the data collection and analysis workflow have not been defined. In this study, we conducted a rigorous comparison of different methodologies for mapping invasive Emergent (Typha …

Go to article

Experimental Measurement Of Sharp Thz Absorption Signatures From Nucleic Acid Solutions In Nanofluidic Channels, Elliott R. Brown, Edgar A. Mendoza Dec 2021

Experimental Measurement Of Sharp Thz Absorption Signatures From Nucleic Acid Solutions In Nanofluidic Channels, Elliott R. Brown, Edgar A. Mendoza

Physics Faculty Publications

We report on the room-temperature experimental measurement of THz absorption signatures in aqueous, double-stranded nucleic acid solutions confined to the submicron silica channels on fused quartz substrates using THz frequency-domain (photomixing) spectroscopy. Three sharp (i.e., strong and narrow) signatures, ~10–20 GHz FWHM, are observed in the shortest base pair sample—small interfering, double-stranded (ds) RNA—in the range of 800 GHz to 1.1 THz. Three similar signatures are also observed in a 50-bp dsDNA ladder sample. For a 1-kbp dsDNA ladder sample, the three are still evident, but are broadened and weakened. For a 48.5-kbp sample (λ-DNA), no prominent signatures are observed, …

Go to article

Supercritical Co2 Recompression Closed Brayton Cycle Analysis, Andres Eduardo Gutierrez Hernandez Dec 2021

Supercritical Co2 Recompression Closed Brayton Cycle Analysis, Andres Eduardo Gutierrez Hernandez

Open Access Theses & Dissertations

On this research, the results of an analysis made of a Supercritical Carbon Dioxide (sCO2) Recuperated Closed Brayton Cycle (RCBC) done by performing theorical calculations and comparing it to the results obtained with the use of the software ASPEN Plus will be presented. To demonstrate and determine that this software is a useful tool for modeling the proposed type of cycle, a preliminary comparison was made to verify with previous studies found in literature. A comparison and analysis between the possible working fluids and thermal energy sources was also performed to emphasize the decision of using CO2 as the cycle …

Go to article

Examining The Effects Of Information And Communication Technologies In The Legal Representation Of Latin American Asylum Seekers, Victor M. Portillo Ochoa Dec 2021

Examining The Effects Of Information And Communication Technologies In The Legal Representation Of Latin American Asylum Seekers, Victor M. Portillo Ochoa

Open Access Theses & Dissertations

The purpose of this thesis was to explore how legal defense nonprofit organizations (NPO) are using Information and Communication Technologies (ICT) to provide legal defense for asylum seekers and improve the conditions of immigrants at detention centers. In addition, this research explored the impact of ICTs on legal defense NPOs, bottlenecks, and security implications when supporting vulnerable communities. ICTs profoundly impacted the way we interact in a post-pandemic world, and it presents new challenges and possibilities for legal defense nonprofit organizations that are helping vulnerable communities. This study consists of staff and volunteers from different legal defense nonprofit organizations NPOs …

Go to article

Millipyde: A Cross-Platform Python Framework For Transparent Gpu Acceleration, James B. Asbury Dec 2021

Millipyde: A Cross-Platform Python Framework For Transparent Gpu Acceleration, James B. Asbury

Master's Theses

The prevalence of general-purpose GPU computing continues to grow and tackle a wider variety of problems that benefit from GPU-acceleration. This acceleration often suffers from a high barrier to entry, however, due to the complexity of software tools that closely map to the underlying GPU hardware, the fast-changing landscape of GPU environments, and the fragmentation of tools and languages that only support specific platforms. Because of this, new solutions will continue to be needed to make GPGPU acceleration more accessible to the developers that can benefit from it. AMD’s new cross-platform development ecosystem ROCm provides promise for developing applications and …

Go to article

Jited: A Framework For Jit Education In The Classroom, Caleb Watts Dec 2021

Jited: A Framework For Jit Education In The Classroom, Caleb Watts

Master's Theses

The study of programming languages is a rich field within computer science, incorporating both the abstract theoretical portions of computer science and the platform specific details. Topics studied in programming languages, chiefly compilers or interpreters, are permanent fixtures in programming that students will interact with throughout their career. These systems are, however, considerably complicated, as they must cover a wide range of functionality in order to enable languages to be created and run. The process of educating students thus requires that the demanding workload of creating one of the systems be balanced against the time and resources present in a …

Go to article

2021 December - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University Dec 2021

2021 December - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Go to article

Predictors Of Poor Glycemic Control In Diabetic Clients With Mental Health Illness, Community Alliance, Omaha, Nebraska, Rachelle Flick Dec 2021

Predictors Of Poor Glycemic Control In Diabetic Clients With Mental Health Illness, Community Alliance, Omaha, Nebraska, Rachelle Flick

Capstone Experience: Master of Public Health

People with severe mental illness tend to die 10-25 years earlier than the general population (WHO). Main contributors to these premature deaths include comorbidities such as hypertension, cardiovascular disease, and diabetes. Diabetes prevalence in mentally ill people is 2 times higher than the general population (WHO). The World Health Organization is taking action to improve the health of people with severe mental illness. These efforts include creating protocols of prevention, identification, assessment, and treatment for mentally ill people, as well as improving access to general health services through the integration of physical and mental health services. Community Alliance, located in …

Go to article

Studying Users Interactions And Behavior In Social Media Using Natural Language Processing, Sultan Alshamrani Dec 2021

Studying Users Interactions And Behavior In Social Media Using Natural Language Processing, Sultan Alshamrani

Electronic Theses and Dissertations, 2020-2023

Social media platforms have been growing at a rapid pace, attracting users' engagement with the online content due to their convenience facilitated by many useful features. Such platforms provide users with interactive options such as likes, dislikes as well as a way of expressing their opinions in the form of text (i.e., comments). As more people engage in different social media platforms, such platforms will increase in both size and importance. This growth in social media data is becoming a vital new area for scholars and researchers to explore this new form of communication. The huge data from social media …

Go to article

Machine Learning Techniques For Topic Detection And Authorship Attribution In Textual Data, Fereshteh Jafariakinabad Dec 2021

Machine Learning Techniques For Topic Detection And Authorship Attribution In Textual Data, Fereshteh Jafariakinabad

Electronic Theses and Dissertations, 2020-2023

The unprecedented expansion of user-generated content in recent years demands more attempts of information filtering in order to extract high-quality information from the huge amount of available data. In this dissertation, we begin with a focus on topic detection from microblog streams, which is the first step toward monitoring and summarizing social data. Then we shift our focus to the authorship attribution task, which is a sub-area of computational stylometry. It is worth mentioning that determining the style of a document is orthogonal to determining its topic, since the document features which capture the style are mainly independent of its …

Go to article

Spectral Dependence Of Deep Subwavelength Metallic Apertures In The Mid-Wave Infrared, Heath Gemar Dec 2021

Spectral Dependence Of Deep Subwavelength Metallic Apertures In The Mid-Wave Infrared, Heath Gemar

Electronic Theses and Dissertations, 2020-2023

For two decades, extraordinary optical transmission (EOT) has amplified exploration into subwavelength systems. Researchers have previously suggested exploiting the spectrally selective electromagnetic field confinement of subwavelength cavities for multispectral detectors. Utilizing the finite-difference frequency domain (FDFD) method, we examine electromagnetic field confinement in both 2-dimensional and 3-dimensional scenarios from 2.5 to 6 microns (i.e., mid-wave infrared or MWIR). We explore the trade space of deep subwavelength cavities and its impact on resonant enhancement of the electromagnetic field. The studies provide fundamental understanding of the coupling mechanisms allowing for prediction of resonant spectral behavior based on cavity geometry and material properties. …

Go to article

Volatiles Characterization During Whiskey Production Using Headspace - Solid Phase Microextraction - Gas Chromatography - Mass Spectrometry, Robert H. Magnuson Dec 2021

Volatiles Characterization During Whiskey Production Using Headspace - Solid Phase Microextraction - Gas Chromatography - Mass Spectrometry, Robert H. Magnuson

Chemistry & Biochemistry Theses - Archive

Whiskey is the second most consumed distilled alcoholic beverage type, by brand, on the planet behind Chinese Baijiu. A prominent component in many varieties of whiskey, maize, contributes a wide profile of compounds that undergo modification in the production pathway, ultimately influencing the final flavor profile. In this study, headspace/solid phase microextraction-gas chromatography/mass spectrometry (HS/SPME-GC/MS) was used to characterize the volatile profile of 5 different maize varieties, mashes produced from each, and 4 post-fermentation mixtures. Headspace sampling was performed using a high capacity SPME Arrow device, in an effort maximize the species detected. Compound identification was supplied by matches within …

Go to article

Use Patterns And Influencing Factors Of Irrigation Best Management Practices In The Lower Mississippi River Basin, Merri E. Day Dec 2021

Use Patterns And Influencing Factors Of Irrigation Best Management Practices In The Lower Mississippi River Basin, Merri E. Day

Graduate Theses and Dissertations

This study uses the 2016 Irrigation Survey from Arkansas, Louisiana, and Mississippi to document the use of irrigation best management practices (IBMPs), analyze use patterns, and use quantitative methods to determine factors that influence producers’ decisions regarding IBMPs. IBMPs included in the survey can be grouped as: field management practices (zero-grade leveling, precision-grade leveling, end blocking, warped surface, and deep tillage), water flow control practices (computerized pipe-hole selection, multiple-inlet irrigation, surge irrigation, alternate wetting and drying, cutback irrigation, flow meters, and pump timers), water recovery/storage practices (tail-water recovery system and on-farm storage reservoir), and advanced irrigation scheduling practices (soil moisture …

Go to article

Using Iphone Significant Location Data To Improve Air Pollution Exposure Estimation, Elizabeth Eastman Dec 2021

Using Iphone Significant Location Data To Improve Air Pollution Exposure Estimation, Elizabeth Eastman

Electronic Theses and Dissertations, 2020-2023

An accurate estimation of human exposure to ambient air pollution is crucial for air pollution health studies. Time-activity patterns may introduce substantial uncertainties in exposure estimation. As smartphones are becoming increasingly popular and their ownership is becoming ubiquitous in the US. Virtually all smartphones can collect location data, and such data is continuously somewhere. Therefore, it is clear that such stored location data has the potential to be used for characterizing an individual's time-activity patterns for air pollution health studies. However, studies on the accuracy and feasibility of using a smartphone's location data in air pollution exposure estimation are still …

Go to article

Utilizing High Throughput Computing Techniques For The Predictions Of Spectroscopic Properties Of Astrophysically Relevant Molecules, Brian Ferrari Dec 2021

Utilizing High Throughput Computing Techniques For The Predictions Of Spectroscopic Properties Of Astrophysically Relevant Molecules, Brian Ferrari

Electronic Theses and Dissertations, 2020-2023

Here, we utilize Quantum Chemistry (QC) approaches to predict the structures, vibrational frequencies, infrared intensities and Raman activities of unusual molecular species using the General Atomic and Molecular Structure System (GAMESS(US)) package. A Python-based software, AutoGAMESS, was developed to automate the workflow and take advantage of High Throughput Computing (HTC) techniques enabling the automated generation of spectroscopic data from hundreds of calculations. This approach was utilized to determine these properties for a series of carbon oxides (C2On; n = 3 to 4), anticipated to be produced during the radiation of pure carbon dioxide ices, under conditions relevant to the interstellar …

Go to article

High Spectral Brightness, Broad Area Quantum Cascade Lasers, Enrique Sanchez Cristobal Dec 2021

High Spectral Brightness, Broad Area Quantum Cascade Lasers, Enrique Sanchez Cristobal

Electronic Theses and Dissertations, 2020-2023

Quantum cascade lasers are unipolar semiconductor lasers that offer a unique combination of compact size, high efficiency, high optical power, and flexibility to achieve a targeted emission wavelength with the same laser core material composition, employing so-called bandgap engineering. Since their invention in 1994, watt-level CW power with 5 to 20 % wallplug efficiency was demonstrated for QCLs throughout the entire 4 to 12 µm range, which makes QCLs very attractive for a number of practical applications. Our earlier work on broad-area QCLs emitting in the 4.6 µm to 5.7 µm spectral range demonstrated that CW power scaling with lateral …

Go to article

Wavelet Particle Hydrodynamics For Less Smooth Flow, Oddny Brun Dec 2021

Wavelet Particle Hydrodynamics For Less Smooth Flow, Oddny Brun

Electronic Theses and Dissertations, 2020-2023

The purpose of this research was to improve the smoothing operation in smoothed particle hydrodynamics, SPH, when the flow of matter is not smooth. Our main focuses are on the kernel selection, identifying the discontinuities in the sequences to be smoothed, and use of the Laplacian as opposed to artificial viscosity for improved physical accuracy. The results show that alternative kernels result in differences in how matter flows. These effects are explained by the kernels' gradient and Laplacian properties. Five alternative kernels were included in our analysis and our SPH-based simulation cases. Further, the sequences to be smoothed by the …

Go to article

Nonlinear Light-Matter Interactions In Novel Crystals For Broadband Mid-Infrared Generation, Taiki Kawamori Dec 2021

Nonlinear Light-Matter Interactions In Novel Crystals For Broadband Mid-Infrared Generation, Taiki Kawamori

Electronic Theses and Dissertations, 2020-2023

Mid-infrared (MIR) laser sources have demonstrated diverse applications in science and technology. For spectroscopy applications, numerous molecules have unique absorption features in this range, and one needs a spectrally broad coherent laser source for parallel detection of mixtures of species. Frequency down-conversion in nonlinear optical materials via second-order nonlinear susceptibility is one of the promising techniques to generate the spectral coverage of more than an octave in the MIR, assisted by emerging novel crystals. The nonlinear light-matter interactions in such special crystals as ZnSe ceramics have not been analyzed. Additionally, through the use of high-intensity few-cycle optical pulses, high-order nonlinear …

Go to article

First Prev Next Last