Physical Sciences and Mathematics Commons^™

Atmospheric Organic Matter In Clouds: Exact Masses And Molecular Formula Identification Using Ultrahigh-Resolution Ft-Icr Mass Spectrometry, Y. Zhao, A. G. Hallar, Lynn Mazzoleni

Department of Chemistry Publications

Clouds alter the composition of atmospheric aerosol by acting as a medium for interactions between gas- and particulate-phase substances. To determine the cloud water atmospheric organic matter (AOM) composition and study the cloud processing of aerosols, two samples of supercooled clouds were collected at the Storm Peak Laboratory near Steamboat Springs, Colorado (3220 m a.s.l.). Approximately 3000 molecular formulas were assigned to ultrahigh-resolution mass spectra of the samples after using a reversed-phase extraction procedure to isolate the AOM components from the cloud water. Nitrogen-containing compounds (CHNO compounds), sulfur-containing compounds (CHOS and CHNOS compounds) and other oxygen-containing compounds (CHO compounds) with …

Photoacoustic And Nephelometric Spectroscopy Of Aerosol Optical Properties With A Supercontinuum Light Source, Neha Sharma, I. J. Arnold, H. Moosmüller, W. P. Arnott, C. Mazzoleni

Michigan Tech Publications

A novel multi-wavelength photoacousticnephelometer spectrometer (SC-PNS) has been developed for the optical characterization of atmospheric aerosol particles. This instrument integrates a white light supercontinuum laser with photoacoustic and nephelometric spectroscopy to measure aerosol absorption and scattering coefficients at five wavelength bands (centered at 417, 475, 542, 607, and 675 nm). These wavelength bands are selected from the continuous spectrum of the laser (ranging from 400-2200 nm) using a set of optical interference filters. Absorption and scattering measurements on laboratory-generated aerosol samples were performed sequentially at each wavelength band. To test the instrument we measured the wavelength dependence of absorption and …

Shifting Environmental Controls On Ch4 Fluxes In A Sub-Boreal Peatland, Thomas G. Pypker, P. A. Moore, John A. Hribljan, Rodney Chimner

Michigan Tech Publications

We monitored CO₂ and CH₄ fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH₄ from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH₄ over the measurement period. Net daily CH₄ fluxes increased from 70 mg CH₄ m⁻² d⁻¹ to 220 mg CH₄ m⁻² d⁻¹ from mid May to mid July. After July, CH_{4 …}

La Yeguada Volcanic Vomplex In The Republic Of Panama: An Assessment Of The Geologic Hazards Using 40ar/39ar Geochronology, Karinne L. Knutsen, William I. Rose, Brian Jicha

Department of Geological and Mining Engineering and Sciences Publications

La Yeguada volcanic complex is one of three Quaternary volcanic centers in Panama. To assess potential geologic hazards, new samples were analyzed using argon analysis (⁴⁰Ar/³⁹Ar), and obtained the following: the most recent eruption occurred approximately 32,000 years ago at the Media Luna cinder cone; the youngest dated eruption from the main dome complex occurred 357 ± 19 ka, producing the Castillo dome unit; Cerro Picacho, a separate dacite dome 1.5 km east of the main complex is 4.47 ± 0.23 Ma; and the El Satro Pyroclastic Flow unit surrounds the northern portion of the volcanic …

Modeling Acute Respiratory Illness During The 2007 San Diego Wildland Fires Using A Coupled Emissions-Transport System And General Additive Modeling, Brian Thelen, Nancy H. F. French, Benjamin W. Koziol, Michael Billmire, Robert Chris Owen, Jeffrey Johnson, Michele Ginsberg, Tatiana Loboda, Shiliang Wu

Michigan Tech Research Institute Publications

Background

A study of the impacts on respiratory health of the 2007 wildland fires in and around San Diego County, California is presented. This study helps to address the impact of fire emissions on human health by modeling the exposure potential of proximate populations to atmospheric particulate matter (PM) from vegetation fires. Currently, there is no standard methodology to model and forecast the potential respiratory health effects of PM plumes from wildland fires, and in part this is due to a lack of methodology for rigorously relating the two. The contribution in this research specifically targets that absence by modeling …

Formation Of Nanodiamonds At Near-Ambient Conditions Via Microplasma Dissociation Of Ethanol Vapour, Ajay Kumar, Pin Ann Lin, Albert Xue, Boyi Hao, Yoke Khin Yap, R. Mohan Sankaran

Department of Physics Publications

Clusters of diamond-phase carbon, known as nanodiamonds, exhibit novel mechanical, optical and biological properties that have elicited interest for a wide range of technological applications. Although diamond is predicted to be more stable than graphite at the nanoscale, extreme environments are typically used to produce nanodiamonds. Here we show that nanodiamonds can be stably formed in the gas phase at atmospheric pressure and neutral gas temperatures <100 °C by dissociation of ethanol vapour in a novel microplasma process. Addition of hydrogen gas to the process allows in flight purification by selective etching of the non-diamond carbon and stabilization of the nanodiamonds. The nanodiamond particles are predominantly between 2 and 5 nm in diameter, and exhibit cubic diamond, n-diamond and lonsdaleite crystal structures, similar to nanodiamonds recovered from meteoritic residues. These results may help explain the origin of nanodiamonds in the cosmos, and offer a simple and inexpensive route for the …

The Fine-Scale Structure Of The Trade Wind Cumuli Over Barbados – An Introduction To The Carriba Project, H. Siebert, M. Beals, J. Bethke, E. Bierwirth, T. Conrath, K. Dieckmann, F. Ditas, A. Ehrlich, D. Farrell, S. Hartmann, M. A. Izaguirre, J. Katzwinkel, L. Nuijens, G. Roberts, M. Schäfer, R. A. Shaw, T. Schmeissner, I. Serikov, B. Stevens, F. Stratmann, B. Wehner, M. Wendisch, F. Werner, H. Wex

Michigan Tech Publications

The CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) project, focused on high resolution and collocated measurements of thermodynamic, turbulent, microphysical, and radiative properties of trade wind cumuli over Barbados, is introduced. The project is based on two one-month field campaigns in November 2010 (climatic wet season) and April 2011 (climatic dry season). Observations are based on helicopter-borne and ground-based measurements in an area of 100 km2 off the coast of Barbados. CARRIBA is accompanied by long-term observations at the Barbados Cloud Observatory located at the East coast of Barbados since early in 2010 and …

The Size Range Of Bubbles That Produce Ash During Explosive Volcanic Eruptions, Kimberly Genareau, Gopal K. Mulukutla, Alexander A. Proussevitch, Adam J. Durant, William I. Rose, Dork L. Sahagian

Department of Geological and Mining Engineering and Sciences Publications

Volcanic eruptions can produce ash particles with a range of sizes and morphologies. Here we morphologically distinguish two textural types: Simple (generally smaller) ash particles, where the observable surface displays a single measureable bubble because there is at most one vesicle imprint preserved on each facet of the particle; and complex ash particles, which display multiple vesicle imprints on their surfaces for measurement and may contain complete, unfragmented vesicles in their interiors. Digital elevation models from stereo-scanning electron microscopic images of complex ash particles from the 14 October 1974 sub-Plinian eruption of Volcán Fuego, Guatemala and the 18 May 1980 …

Radar Measurements Of Nhtsa’S Surrogate Vehicle ‘Ss-V’, William Buller, Brian Wilson, James Ebling, Line Van Nieuwstadt, Benjamin E. Hart

Michigan Tech Research Institute Publications

NHTSA seeks to objectively quantify the performance of forward-looking advanced technologies such as Crash Imminent Braking (CIB) and Dynamic Brake Support (DBS) on the test track. Since these evaluations are expected to result in collisions between the subject vehicle (SV) and a principal other vehicle (POV) positioned directly in front of it, safety necessitates that the POV be a surrogate. However, to insure the tests will provide an accurate assessment of the SV’s CIB and/or DBS capabilities, the surrogate must present as realistic. One way “realism” must be quantified involves a surrogate’s radar return characteristics. The tests described in this …

Algebraic Techniques In Designing Quantum Synchronizable Codes, Yuichiro Fujiwara, Vladimir Tonchev, Tony Wong

Department of Mathematical Sciences Publications

Quantum synchronizable codes are quantum error-correcting codes that can correct the effects of quantum noise as well as block synchronization errors. We improve the known general framework for designing quantum synchronizable codes through more extensive use of the theory of finite fields. This makes it possible to widen the range of tolerable magnitude of block synchronization errors while giving mathematical insight into the algebraic mechanism of synchronization recovery. Also given are families of quantum synchronizable codes based on punctured Reed-Muller codes and their ambient spaces.

Shape-Induced Gravitational Sorting Of Saharan Dust During Transatlantic Voyage: Evidence From Caliop Lidar Depolarization Measurements, Weidong Yang, Alexander Marshak, Alexander Kostinski, Tamás Várnai

Department of Physics Publications

Motivated by the physical picture of shape‐dependent air resistance and, consequently, shape‐induced differential sedimentation of dust particles, we searched for and found evidence of dust particle asphericity affecting the evolution and distribution of dust‐scattered light depolarization ratio (δ). Specifically, we examined a large data set of Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) observations of Saharan dust from June to August 2007. Observing along a typical transatlantic dust track, we find that (1) median δ is uniformly distributed between 2 and 5 km altitudes as the elevated dust leaves the west coast of Africa, thereby indicating uniformly random mixing of particle …

Inhibition Of Fast Axonal Transport By Pathogenic Sod1 Involves Activation Of P38 Map Kinase, Gerardo Morfini, Daryl Bosco, Hannah Brown, Rodolfo Gatto, Agnieszka Kaminska, Yuyu Song, Ashutosh Tiwari, Et. Al.

Department of Chemistry Publications

Dying-back degeneration of motor neuron axons represents an established feature of familial amyotrophic lateral sclerosis (FALS) associated with superoxide dismutase 1 (SOD1) mutations, but axon-autonomous effects of pathogenic SOD1 remained undefined. Characteristics of motor neurons affected in FALS include abnormal kinase activation, aberrant neurofilament phosphorylation, and fast axonal transport (FAT) deficits, but functional relationships among these pathogenic events were unclear. Experiments in isolated squid axoplasm reveal that FALS-related SOD1 mutant polypeptides inhibit FAT through a mechanism involving a p38 mitogen activated protein kinase pathway. Mutant SOD1 activated neuronal p38 in mouse spinal cord, neuroblastoma cells and squid axoplasm. Active p38 …

Record-Breaking Statistics For Random Walks In The Presence Of Measurement Error And Noise, Yaniv Edrey, Alexander Kostinski, Satya N. Majumdar, Brian Berkowitz

Department of Physics Publications

We examine distance record setting by a random walker in the presence of a measurement error δ and additive noise γ and show that the mean number of (upper) records up to n steps still grows universally as ⟨R_n⟩∼n^1/2 for large n for all jump densities, including Lévy distributions, and for all δ and γ. In contrast, the pace of record setting, measured by the amplitude of the n^1/2 growth, depends on δ and γ. In the absence of noise (γ=0), the amplitude S(δ) is evaluated explicitly for arbitrary jump distributions and it decreases monotonically with …

Applicability Of Carbon And Boron Nitride Nanotubes As Biosensors: Effect Of Biomolecular Adsorption On The Transport Properties Of Carbon And Boron Nitride Nanotubes, Xiaoliang Zhong, Saikat Mukhopadhyay, Gowtham S, Ravindra Pandey, Shashi P. Karna

Data Science Publications

The effect of molecular adsorption on the transport properties of single walled carbon and boron nitride nanotubes (CNTs and BNNTs) is investigated using density functional theory and nonequilibrium Green’s function methods. The calculated I-V characteristics predict noticeable changes in the conductivity of semiconducting BNNTs due to physisorption of nucleic acid base molecules. Specifically, guanine which binds to the side wall of BNNT significantly enhances its conductivity by introducing conduction channels near the Fermi energy of the bioconjugated system. For metallic CNTs, a large background current masks relatively small changes in current due to the biomolecular adsorption. The results therefore suggest …

Enumeration Of (16,4,16,4) Relative Difference Sets, David C. Clark, Vladimir Tonchev

Department of Mathematical Sciences Publications

A complete enumeration of relative difference sets (RDS) with parameters (16, 4, 16, 4) in a group of order 64 with a normal subgroup N of order 4 is given. If N = Z₄ , three of the 11 abelian groups of order 64, and 23 of the 256 nonabelian groups of order 64 contain (16, 4, 16, 4) RDSs. If N = Z₂ × Z₂ , nine of the abelian groups and 194 of the non-abelian groups of order 64 contain (16, 4, 16, 4) RDSs.

Hetero-Junctions Of Boron Nitride And Carbon Nanotubes: Synthesis And Characterization, Yoke Khin Yap

Department of Physics Publications

Hetero-junctions of boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) are expected to have appealing new properties that are not available from pure BNNTs and CNTs. Theoretical studies indicate that BNNT/CNT junctions could be multifunctional and applicable as memory, spintronic, electronic, and photonics devices with tunable band structures. This will lead to energy and material efficient multifunctional devices that will be beneficial to the society. However, experimental realization of BNNT/CNT junctions was hindered by the absent of a common growth technique for BNNTs and CNTs. In fact, the synthesis of BNNTs was very challenging and may involve high temperatures (up …

Exploring Techniques For Vision Based Human Activity Recognition: Methods, Systems, And Evaluation, Xin Xu, Jinshan Tang, Xiaolong Zhang, Xiaoming Liu, Hong Zhang, Yimin Qiu

Michigan Tech Publications

With the wide applications of vision based intelligent systems, image and video analysis technologies have attracted the attention of researchers in the computer vision field. In image and video analysis, human activity recognition is an important research direction. By interpreting and understanding human activity, we can recognize and predict the occurrence of crimes and help the police or other agencies react immediately. In the past, a large number of papers have been published on human activity recognition in video and image sequences. In this paper, we provide a comprehensive survey of the recent development of the techniques, including methods, systems, …

On-Chip Non-Reciprocal Optical Devices Based On Quantum Inspired Photonic Lattices, Ramy El-Ganainy, A. Eisfeld, Miguel Levy, Demetrios N. Christodoulides

Department of Physics Publications

We propose integrated optical structures that can be used as isolators and polarization splitters based on engineered photonic lattices. Starting from optical waveguide arrays that mimic Fock space (quantum state with a well-defined particle number) representation of a non-interacting two-site Bose Hubbard Hamiltonian, we show that introducing magneto-optic nonreciprocity to these structures leads to a superior optical isolation performance. In the forward propagation direction, an input TM polarized beam experiences a perfect state transfer between the input and output waveguide channels while surface Bloch oscillations block the backward transmission between the same ports. Our analysis indicates a large isolation ratio …

Simulation Of Charge Transport In Multi-Island Tunneling Devices: Application To Disordered One-Dimensional Systems At Low And High Biases, Madhusudan A. Savaikar, Douglas R. Banyai, Paul Bergstrom, John A. Jaszczak

Department of Physics Publications

Although devices have been fabricated displaying interesting single-electron transport characteristics, there has been limited progress in the development of tools that can simulate such devices based on their physical geometry over a range of bias conditions up to a few volts per junction. In this work, we present the development of a multi-island transport simulator, MITS, a simulator of tunneling transport in multi-island devices that takes into account geometrical and material parameters, and can span low and high source-drain biases. First, the capabilities of MITS are demonstrated by modeling experimentaldevices described in the literature, and showing that the simulated device …

Acetyl Radical In Tobacco Smoke: Detection, Quantification And Simulation, Na Hu

Dissertations, Master's Theses and Master's Reports - Open

Free radicals are present in cigarette smoke and can have a negative effect on human health by attacking lipids, nucleic acids, proteins and other biologically important species. However, because of the complexity of the tobacco smoke system and the dynamic nature of radicals, little is known about the identity of the radicals, and debate continues on the mechanisms by which those radicals are produced. In this study, acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5- tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high performance liquid chromatography (HPLC), mass …

A Study Of The Impacts Of Freeze-Thaw On Cliff Recession At The Calvert Cliffs In Calvert County, Maryland, Bonnie Elizabeth Zwissler

Dissertations, Master's Theses and Master's Reports - Open

The Calvert Cliffs, which form much of the western coastline of the Chesapeake Bay in Calvert County, Maryland, are actively eroding and destabilizing, resulting in a critical situation for many homes in close proximity to the slope's crest. Past studies have identified that where waves directly interact with the toe of the slope, wave action controls cliff recession; however, where waves do not regularly interact with the slope toe, the past work identified that freeze-thaw controls recession. This study investigated the validity of this second claim by analyzing the recession rate and freeze-thaw behavior of six study sites along the …

Spatial And Temporal Evolution Of The Volcanics And Sediments Of The Kenya Rift, Alexandria L. Guth

Dissertations, Master's Theses and Master's Reports - Open

New volumetric and mass flux estimates have been calculated for the Kenya Rift. Spatial and temporal histories for volcanic eruptions, lacustrine deposition, and hominin fossil sites are presented, aided by the compilation of a new digital geologic map. Distribution of volcanism over time indicates several periods of southward expansion followed by relative positional stasis. Volcanism occurs throughout the activated rift length, with no obvious abandonment as the rift system migrated. The main exception is a period of volcanic concentration around 10 Ma, when activity was constrained within 2° of the equator.

Volumes derived from seismic data indicate a total volume …

Evaluation Of Non-Stationarity In Annual Maximum Flood Series Of Moderately Impaired Watersheds In The Upper Midwest And Northeastern United States, Neila Salvadori

Dissertations, Master's Theses and Master's Reports - Open

United States federal agencies assess flood risk using Bulletin 17B procedures which assume annual maximum flood series are stationary. This represents a significant limitation of current flood frequency models as the flood distribution is thereby assumed to be unaffected by trends or periodicity of atmospheric/climatic variables and/or anthropogenic activities. The validity of this assumption is at the core of this thesis, which aims to improve understanding of the forms and potential causes of non-stationarity in flood series for moderately impaired watersheds in the Upper Midwest and Northeastern US. Prior studies investigated non-stationarity in flood series for unimpaired watersheds; however, as …

Electron Transport In Low-Dimensional Nanostructures - Theoretical Study With Application, Xiaoliang Zhong

Dissertations, Master's Theses and Master's Reports - Open

Graphene as a carbon monolayer has attracted extensive research interest in recent years. My research work within the frame of density functional theory has suggested that positioning graphene in proximity to h-BN may induce a finite energy gap in graphene, which is important for device applications. For an AB-stacked graphene/BN bilayer, a finite gap is induced at the equilibrium configuration. This induced gap shows a linear relationship with the applied strain. For a graphene/BN/graphene trilayer, a negligible gap is predicted in the ground state due to the overall symmetry of the system. When an electric field is applied, a tunable …

Nonlinear Effects In Magnetic Garnet Films And Nonreciprocal Optical Bloch Oscillations In Waveguide Arrays, Pradeep Kumar

Dissertations, Master's Theses and Master's Reports - Open

This dissertation presents detailed experimental and theoretical investigations of nonlinear and nonreciprocal effects in magnetic garnet films. The dissertation thus comprises two major sections. The first section concentrates on the study of a new class of nonlinear magneto-optic thin film materials possessing strong higher order magnetic susceptibility for nonlinear optical applications. The focus was on enlarging the nonlinear performance of ferrite garnet films by strain generation and compositional gradients in the sputter-deposition growth of these films. Under this project several bismuth-substituted yttrium iron garnet (Bi,Y) ₃ (Fe,Ga)₅ O₁₂(acronym as Bi:YIG) films have been sputter-deposited over gadolinium gallium …

Properties And Structures Of Li-N Based Hydrogen Storage Materials, Junqing Zhang

Dissertations, Master's Theses and Master's Reports - Open

Traditional transportation fuel, petroleum, is limited and nonrenewable, and it also causes pollutions. Hydrogen is considered one of the best alternative fuels for transportation. The key issue for using hydrogen as fuel for transportation is hydrogen storage. Lithium nitride (Li3N) is an important material which can be used for hydrogen storage. The decompositions of lithium amide (LiNH2) and lithium imide (Li2NH) are important steps for hydrogen storage in Li3N. The effect of anions (e.g. Cl-) on the decomposition of LiNH2 has never been studied. Li3N can react with LiBr to form lithium nitride bromide Li13N4Br which has been proposed as …

Modern Computational Chemistry Methods For Prediction Of Ground- And Excited-State Properties In Open-Shell Systems, Nina Tyminska

Dissertations, Master's Theses and Master's Reports - Open

The main goal of the research presented in this work is to provide some important insights about computational modeling of open-shell species. Such projects are: the investigation of the size-extensivity error in Equation-of-Motion Coupled Cluster methods, the analysis of the Long-Range corrected scheme in predicting UV-Vis spectra of Cu(II) complexes with the 4-imidazole acetate and its ethylated derivative, and the exploration of the importance of choosing a proper basis set for the description of systems such as the lithium monoxide anion. The most significant findings of this research are: (i) The contribution of the left operator to the size-extensivity error …

Ground-Based And Satellite Remote Sensing Of Paroxysmal Eruptions At Etna Volcano, 2011-2012., Estelle Bonny

Dissertations, Master's Theses and Master's Reports - Open

Mt Etna's activity has increased during the last decade with a tendency towards more explosive eruptions that produce paroxysmal lava fountains. From January 2011 to April 2012, 25 lava fountaining episodes took place at Etna's New South-East Crater (NSEC). Improved understanding of the mechanism driving these explosive basaltic eruptions is needed to reduce volcanic hazards. This type of activity produces high sulfur dioxide (SO2) emissions, associated with lava flows and ash fall-out, but to date the SO2 emissions associated with Etna's lava fountains have been poorly constrained. The Ultraviolet (UV) Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the …

Validation Of A 'Displacement Tomography' Inversion Method For Modeling Sheet Intrusions, Sarah J. Menassian

Dissertations, Master's Theses and Master's Reports - Open

The study of volcano deformation data can provide information on magma processes and help assess the potential for future eruptions. In employing inverse deformation modeling on these data, we attempt to characterize the geometry, location and volume/pressure change of a deformation source. Techniques currently used to model sheet intrusions (e.g., dikes and sills) often require significant a priori assumptions about source geometry and can require testing a large number of parameters. Moreover, surface deformations are a non-linear function of the source geometry and location. This requires the use of Monte Carlo inversion techniques which leads to long computation times. Recently, …

Simulations Of Newtonian And Non-Newtonian Flows In Deformable Tubes, Abdallah A. Al-Habahbeh

Dissertations, Master's Theses and Master's Reports - Open

Computational models for the investigation of flows in deformable tubes are developed and implemented in the open source computing environment OpenFOAM. Various simulations for Newtonian and non-Newtonian fluids under various flow conditions are carried out and analyzed. First, simulations are performed to investigate the flow of a shear-thinning, non-Newtonian fluid in a collapsed elastic tube and comparisons are made with experimental data. The fluid is modeled by means of the Bird-Carreau viscosity law. The computational domain of the deformed tube is constructed from data obtained via computer tomography imaging. Comparison of the computed velocity fields with the ultrasound Doppler velocity …