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Articles 241 - 270 of 325
Full-Text Articles in Physics
A Social Network Analysis Of An Introductory Calculus-Based Physics Class With Comparisons Of Traditional And Non-Traditional Students, Fci Scores, And Network Centralities, Emily Sandt
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The use of social network analysis in physics education research seeks to advance understanding of how students' collaborative tendencies influence trends of learning. Common useful measurements are network size, density of connections, and centrality measures that describe the importance of nodes' positions. This study compared four different centrality measures at the beginning and end of seven sections of an introductory calculus-based physics course. The Force Concept Inventory was used as a measure of conceptual learning at pre- and post-course administrations. The main focus of this study was to identify if differences in network centralities and conceptual learning/knowledge exist with respect …
Surface Effect Of Ferromagnetic Nanoparticles On Transition Between Single- And Multi-Domain Structure Or Between Single-Domain Structure And Superparamagnetic Phase, Hind Adawi
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Surface effects on critical dimensions of ferromagnetic nanoparticles were studied. Algebraic equations were derived and numerically solved for critical radius RC2 of ferromagnetic nanoparticles describing the transition between single- and multi-domain magnetic structure. Results were analyzed to illustrate the effect of surface parameters related to saturation magnetization a, exchange interaction ß, and anisotropy KS on the critical radius of nanoparticles with a core value of anisotropy KV. Available experimental data for MnBi, FePt, and CoPt or for Fe nanoparticles were used as examples of nanoparticles with high and low values of KV, respectively. Our studies clearly show that discrepancies existing …
Terahertz Spectroscopic Breath Analysis As A Viable Analytical Chemical Sensing Technique, Robert M. Schueler
Terahertz Spectroscopic Breath Analysis As A Viable Analytical Chemical Sensing Technique, Robert M. Schueler
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The ability to quantify trace chemicals in human breath enables the possibility of identifying breath biomarkers to aid in diagnosis. The vast majority of the studies in the analytical breath analysis rely on GC-MS techniques for quantification of the human breath composition1,2,3,4. THz spectroscopy of breath is rapid, sensitive, and highly specific molecular identification in complex mixtures containing 10-100 analytes with near `absolute' specificity. THz spectroscopic breath analyzers require chemical preconcentration. A newly developed custom preconcentrator was constructed and compared in its performance to a commercial system. Unlike the commercial counterpart, the new system does not require cryogenic liquids, is …
Heating Power Of Coated Fecov Magnetic Nanoparticles, Hanaa Ali Alshammari
Heating Power Of Coated Fecov Magnetic Nanoparticles, Hanaa Ali Alshammari
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The effect of coatings on the heating curves of magnetic nanoparticles was studied in this Thesis. Iron cobalt vanadium (FeCoV) nanoparticles with oxide (CoOFe2O3) and graphite (C) coating to prevent oxidation, were synthesized through thermal plasma processing method. The magnetic nanoparticles had an average diameter of 30 nm. In the case of FeCoV with oxide coating, the initial diameter of the pure FeCoV nanoparticles on average was 30 nm but after oxidation 5 nm thick oxide layer was created. As a result of this oxidation, the magnetic core of FeCoV nanoparticles was shrunk from 30 nm to 20 nm in …
Use Of Clearview Gel Dosimeter For Quality Assurance And Testing Of Stereotactic Radiosurgery, Erik Joseph-Leonard Courter
Use Of Clearview Gel Dosimeter For Quality Assurance And Testing Of Stereotactic Radiosurgery, Erik Joseph-Leonard Courter
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There exists a lack of accurate, reproducible three-dimensional dosimetry techniques for stereotactic radiosurgery (SRS) commissioning and quality assurance. This experiment evaluates the use of ClearView gel dosimeters as an alternative to current methods for small field dosimetry in SRS testing. ClearView differs from other gel dosimeters in that it uses tetrazolium salt in its chemical make-up in place of traditional Fricke-type compounds. Using a Varian TrueBeam radiotherapy system to deliver the radiation, three vials of ClearView gel dosimeter were tested in three different dose delivery scenarios. The first test examined the dosimeter's response to a static beam with the dose …
Social Network Analysis And The Representation Of Female Students In Introductory Undergraduate Physics, Sarah Teresa Hierath
Social Network Analysis And The Representation Of Female Students In Introductory Undergraduate Physics, Sarah Teresa Hierath
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Physics Education Research has begun to focus on the learning habits, success, and connections of students in physics classrooms using Social Network Analysis (SNA). SNA is an important tool in studying classroom dynamics because it can be used to map the social structure of a classroom's interactions and to aid in understanding how students work and study together. This study presents network diagrams, statistics, centrality measures, and conceptual understanding correlations for 7 different sections of introductory physics. Centrality measures were determined from a first and last week survey in which students were asked to indicate their study partners within the …
Correlations Between Introductory Students’ Attitudes About Physics And Conceptual Understanding, Raym Alzahrani
Correlations Between Introductory Students’ Attitudes About Physics And Conceptual Understanding, Raym Alzahrani
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The purpose of this study is to measure correlations between the students’ incoming attitudes, beliefs and expectations about physics and their conceptual understanding. The study presents a profile of the attitudes and beliefs for Wright State University students who enrolled in calculus-based General Physics I courses during academic years 2014-2015 and 2015-2016. Students’ initial and final attitudes, measured using the CLASS, are correlated with initial and final conceptual gain, measured using the Force Concept Inventory. Students’ initial attitudes (Opre) was correlated with students’ gain (FCIgain) in many sections. Correlations between students’ final attitudes (Opost) and their conceptual understanding (FCIpost), reported …
The Pierre Auger Cosmic Ray Observatory, A. Aab, P. Abreu, M. Aglietta, E. J. Ahn, I. Al Samarai, J. N. Albert, N. Dhital, J. C. Diaz, B. Fick, R. M. Kieckhafer, D. Nitz, T. Yapici
The Pierre Auger Cosmic Ray Observatory, A. Aab, P. Abreu, M. Aglietta, E. J. Ahn, I. Al Samarai, J. N. Albert, N. Dhital, J. C. Diaz, B. Fick, R. M. Kieckhafer, D. Nitz, T. Yapici
Michigan Tech Publications, Part 1
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km2 overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation …
Observations Of New Particle Formation In Enhanced Uv Irradiance Zones Near Cumulus Clouds, B. Wehner, F. Werner, F. Ditas, R. A. Shaw, M. Kulmala, H. Siebert
Observations Of New Particle Formation In Enhanced Uv Irradiance Zones Near Cumulus Clouds, B. Wehner, F. Werner, F. Ditas, R. A. Shaw, M. Kulmala, H. Siebert
Michigan Tech Publications, Part 1
During the CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over Barbados) campaign, the interaction between aerosol particles and cloud microphysical properties was investigated in detail, which also includes the influence of clouds on the aerosol formation. During two intensive campaigns in 2010 and 2011, helicopter-borne measurement flights were performed to investigate the thermodynamic, turbulent, microphysical, and radiative properties of trade-wind cumuli over Barbados. During these flights, 91 cases with increased aerosol particle number concentrations near clouds were detected. The majority of these cases are also correlated with enhanced irradiance in the ultraviolet (UV) spectral wavelength range. …
High-Resolution Measurement Of Cloud Microphysics And Turbulence At A Mountaintop Station, H. Siebert, R. A. Shaw, J. Ditas, T. Schmeissner, S. P. Malinowski, E. Bodenschatz, H. Xu
High-Resolution Measurement Of Cloud Microphysics And Turbulence At A Mountaintop Station, H. Siebert, R. A. Shaw, J. Ditas, T. Schmeissner, S. P. Malinowski, E. Bodenschatz, H. Xu
Michigan Tech Publications, Part 1
Mountain research stations are advantageous not only for long-term sampling of cloud properties but also for measurements that are prohibitively difficult to perform on airborne platforms due to the large true air speed or adverse factors such as weight and complexity of the equipment necessary. Some cloud-turbulence measurements, especially Lagrangian in nature, fall into this category. We report results from simultaneous, high-resolution and collocated measurements of cloud microphysical and turbulence properties during several warm cloud events at the Umweltforschungsstation Schneefernerhaus (UFS) on Zugspitze in the German Alps. The data gathered were found to be representative of observations made with similar …
Schneefernerhaus As A Mountain Research Station For Clouds And Turbulence, S. Risius, H. Xu, F. Di Lorenzo, H. Xi, H. Siebert, R. A. Shaw, E. Bodenschatz
Schneefernerhaus As A Mountain Research Station For Clouds And Turbulence, S. Risius, H. Xu, F. Di Lorenzo, H. Xi, H. Siebert, R. A. Shaw, E. Bodenschatz
Michigan Tech Publications, Part 1
Cloud measurements are usually carried out with airborne campaigns, which are expensive and are limited by temporal duration and weather conditions. Ground-based measurements at high-altitude research stations therefore play a complementary role in cloud study. Using the meteorological data (wind speed, direction, temperature, humidity, visibility, etc.) collected by the German Weather Service (DWD) from 2000 to 2012 and turbulence measurements recorded by multiple ultrasonic sensors (sampled at 10 Hz) in 2010, we show that the Umweltforschungsstation Schneefernerhaus (UFS) located just below the peak of Zugspitze in the German Alps, at a height of 2650 m, is a well-suited station for …
Perturbations Of The Optical Properties Of Mineral Dust Particles By Mixing With Black Carbon: A Numerical Simulation Study, B. V. Scarnato, S. China, K. Nielsen, C. Mazzoleni
Perturbations Of The Optical Properties Of Mineral Dust Particles By Mixing With Black Carbon: A Numerical Simulation Study, B. V. Scarnato, S. China, K. Nielsen, C. Mazzoleni
Michigan Tech Publications, Part 1
Field observations show that individual aerosol particles are a complex mixture of a wide variety of species, reflecting different sources and physico-chemical transformations. The impacts of individual aerosol morphology and mixing characteristics on the Earth system are not yet fully understood. Here we present a sensitivity study on climate-relevant aerosols optical properties to various approximations. Based on aerosol samples collected in various geographical locations, we have observationally constrained size, morphology and mixing, and accordingly simulated, using the discrete dipole approximation model (DDSCAT), optical properties of three aerosols types: (1) bare black carbon (BC) aggregates, (2) bare mineral dust, and (3) …
Ice Nucleation By Water-Soluble Macromolecules, B. G. Pummer, C. Budke, S. Augustin-Bauditz, D. Niedermeier, L. Felgitsch, C. J. Kampf, R. G. Huber, K. R. Liedl, T. Loerting, T. Moschen, M. Schauperl, M. Tollinger, C. E. Morris, H. Wex, H. Grothe, U. Pöschl, T. Koop, J. Fröhlich-Nowoisky
Ice Nucleation By Water-Soluble Macromolecules, B. G. Pummer, C. Budke, S. Augustin-Bauditz, D. Niedermeier, L. Felgitsch, C. J. Kampf, R. G. Huber, K. R. Liedl, T. Loerting, T. Moschen, M. Schauperl, M. Tollinger, C. E. Morris, H. Wex, H. Grothe, U. Pöschl, T. Koop, J. Fröhlich-Nowoisky
Michigan Tech Publications, Part 1
Cloud glaciation is critically important for the global radiation budget (albedo) and for initiation of precipitation. But the freezing of pure water droplets requires cooling to temperatures as low as 235 K. Freezing at higher temperatures requires the presence of an ice nucleator, which serves as a template for arranging water molecules in an ice-like manner. It is often assumed that these ice nucleators have to be insoluble particles. We point out that also free macromolecules which are dissolved in water can efficiently induce ice nucleation: the size of such ice nucleating macromolecules (INMs) is in the range of nanometers, …
Sensing Based On Fano-Type Resonance Response Of All-Dielectric Metamaterials, Elena Semouchkina, Ran Duan, George Semouchkin, Ravindra Pandey
Sensing Based On Fano-Type Resonance Response Of All-Dielectric Metamaterials, Elena Semouchkina, Ran Duan, George Semouchkin, Ravindra Pandey
Michigan Tech Publications, Part 1
A new sensing approach utilizing Mie resonances in metamaterial arrays composed of dielectric resonators is proposed. These arrays were found to exhibit specific, extremely high-Q factor (up to 15,000) resonances at frequencies corresponding to the lower edge of the array second transmission band. The observed resonances possessed with features typical for Fano resonances (FRs), which were initially revealed in atomic processes and recently detected in macro-structures, where they resulted from interference between local resonances and a continuum of background waves. Our studies demonstrate that frequencies and strength of Fano-type resonances in all-dielectric arrays are defined by interaction between local Mie …
A Comprehensive Laboratory Study On The Immersion Freezing Behavior Of Illite Nx Particles: A Comparison Of 17 Ice Nucleation Measurement Techniques, N. Hiranuma, S. Augustin-Bauditz, H. Bingemer, C. Budke, J. Curtius, A. Danielczok, K. Diehl, K. Dreischmeier, M. Ebert, F. Frank, N. Hoffmann, K. Kandler, A. Kiselev, T. Koop, T. Leisner, O. Möhler, B. Nillius, A. Peckhaus, D. Rose, S. Weinbruch, H. Wex, Y. Boose, P. J. Demott, J. D. Hader, T. C.J. Hill, Z. A. Kanji, G. Kulkarni, E. J.T. Levin, C. S. Mccluskey, M. Murakami, B. J. Murray, D. Niedermeier
A Comprehensive Laboratory Study On The Immersion Freezing Behavior Of Illite Nx Particles: A Comparison Of 17 Ice Nucleation Measurement Techniques, N. Hiranuma, S. Augustin-Bauditz, H. Bingemer, C. Budke, J. Curtius, A. Danielczok, K. Diehl, K. Dreischmeier, M. Ebert, F. Frank, N. Hoffmann, K. Kandler, A. Kiselev, T. Koop, T. Leisner, O. Möhler, B. Nillius, A. Peckhaus, D. Rose, S. Weinbruch, H. Wex, Y. Boose, P. J. Demott, J. D. Hader, T. C.J. Hill, Z. A. Kanji, G. Kulkarni, E. J.T. Levin, C. S. Mccluskey, M. Murakami, B. J. Murray, D. Niedermeier
Michigan Tech Publications, Part 1
Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety of instruments have examined immersion freezing activity of atmospherically relevant ice-nucleating particles. However, an intercomparison of these laboratory results is a difficult task because investigators have used different ice nucleation (IN) measurement methods to produce these results. A remaining challenge is to explore the sensitivity and accuracy of these techniques and to understand how the IN results are potentially influenced or biased by experimental parameters associated with these techniques. …
Intercomparing Different Devices For The Investigation Of Ice Nucleating Particles Using Snomax® As Test Substance, H. Wex, S. Augustin-Bauditz, Y. Boose, C. Budke, J. Curtius, K. Diehl, A. Dreyer, F. Frank, S. Hartmann, N. Hiranuma, E. Jantsch, Z. A. Kanji, A. Kiselev, T. Koop, O. Möhler, D. Niedermeier, B. Nillius, M. Rösch, D. Rose, C. Schmidt, I. Steinke, F. Stratmann
Intercomparing Different Devices For The Investigation Of Ice Nucleating Particles Using Snomax® As Test Substance, H. Wex, S. Augustin-Bauditz, Y. Boose, C. Budke, J. Curtius, K. Diehl, A. Dreyer, F. Frank, S. Hartmann, N. Hiranuma, E. Jantsch, Z. A. Kanji, A. Kiselev, T. Koop, O. Möhler, D. Niedermeier, B. Nillius, M. Rösch, D. Rose, C. Schmidt, I. Steinke, F. Stratmann
Michigan Tech Publications, Part 1
Seven different instruments and measurement methods were used to examine the immersion freezing of bacterial ice nuclei from Snomax® (hereafter Snomax), a product containing ice-active protein complexes from non-viable Pseudomonas syringae bacteria. The experimental conditions were kept as similar as possible for the different measurements. Of the participating instruments, some examined droplets which had been made from suspensions directly, and the others examined droplets activated on previously generated Snomax particles, with particle diameters of mostly a few hundred nanometers and up to a few micrometers in some cases. Data were obtained in the temperature range from -2 to -38 °C, …
Laser Guide Star Design Project For The Usaf John Bryan State Park Quad Axis Observatory, Nathan Michael Figlewski
Laser Guide Star Design Project For The Usaf John Bryan State Park Quad Axis Observatory, Nathan Michael Figlewski
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Atmospheric Turbulence has long remained one of the great unsolved problems in physics. Laser guide stars were invented in order for telescopes to overcome atmospheric turbulence while used in combination with adaptive optics. This study focuses on the design and implementation phase of a Rayleigh laser guide star for the John Bryan State Park Observatory, owned and operated by the United States Air Force. Atmospheric simulations, as well as optical modelling of proposed equipment, were completed to optimize the design of this laser guide star. In addition, a novel method for the implementation of the guide star onto this very …
Assessment Of The Applicability Of Terahertz Spectroscopic Breath Sensing Towards Monitoring Type 1 Diabetic Mellitus, Jessica Rose Thomas
Assessment Of The Applicability Of Terahertz Spectroscopic Breath Sensing Towards Monitoring Type 1 Diabetic Mellitus, Jessica Rose Thomas
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Type 1 diabetes is a condition that cumulatively costs around $14.9 billion in medical expenses every year in the United States. Besides being costly, the monitoring of this disease is invasive, painful, and often embarrassing to the afflicted individual; blood and urine testing is currently the daily method of monitoring blood glucose and ketone levels in the body of type 1 diabetics. Though the use of these samples is standard, another avenue for possibly determining blood glucose has not been completely explored. With over 3000 chemicals reportedly found in exhaled human breath, biomarkers associated with this disorder and many of …
The Immersion Mode Ice Nucleation Behavior Of Mineral Dusts: A Comparison Of Different Pure And Surface Modified Dusts, S. Augustin-Bauditz, H. Wex, S. Kanter, M. Ebert, D. Niedermeier, F. Stolz, A. Prager, F. Stratmann
The Immersion Mode Ice Nucleation Behavior Of Mineral Dusts: A Comparison Of Different Pure And Surface Modified Dusts, S. Augustin-Bauditz, H. Wex, S. Kanter, M. Ebert, D. Niedermeier, F. Stolz, A. Prager, F. Stratmann
Michigan Tech Publications, Part 1
In this study we present results from immersion freezing experiments with size-segregated mineral dust particles. Besides two already existing data sets for Arizona Test Dust (ATD), and Fluka kaolinite, we show two new data sets for illite-NX, which consists mainly of illite, a clay mineral, and feldspar, a common crustal material. The experiments were carried out with the Leipzig Aerosol Cloud Interaction Simulator. After comparing the different dust samples, it became obvious that the freezing ability was positively correlated with the K-feldspar content. Furthermore, a comparison of the composition of the ATD, illite-NX, and feldspar samples suggests that within the …
A Semi-Lagrangian View Of Ozone Production Tendency In North American Outflow In The Summers Of 2009 And 2010, B. Zhang, R. C. Owen, J A Perlinger, A. Kumar, S. Wu, M. Val Martin, L. Kramer, D. Helmig, R. E. Honrath
A Semi-Lagrangian View Of Ozone Production Tendency In North American Outflow In The Summers Of 2009 And 2010, B. Zhang, R. C. Owen, J A Perlinger, A. Kumar, S. Wu, M. Val Martin, L. Kramer, D. Helmig, R. E. Honrath
Michigan Tech Publications, Part 1
The Pico Mountain Observatory, located at 2225 m a.s.l. in the Azores Islands, was established in 2001 to observe long-range transport from North America to the central North Atlantic. In previous research conducted at the observatory, ozone enhancement (> 55 ppbv) in North American outflows was observed, and efficient ozone production in these outflows was postulated. This study is focused on determining the causes for high d[O3] / d[CO] values (~1 ppbv ppbv−1) observed in the summers of 2009 and 2010. The folded retroplume technique, developed by Owen and Honrath (2009), was applied to combine upwind FLEXPART transport …
Ultraviolet Rayleigh Scatter Imaging For Spatial Temperature Profiles In Atmospheric Microdischarges, James E. Caplinger
Ultraviolet Rayleigh Scatter Imaging For Spatial Temperature Profiles In Atmospheric Microdischarges, James E. Caplinger
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Spatially resolved temperature measurements within a microdischarge in atmospheric pressure air have been conducted using Rayleigh scattering of a pulsed ultraviolet laser. Scattering intensity images were used to generate a radial profile of translational temperature, with the analysis based on the ideal gas inverse relationship of temperature and gas density. Rayleigh scattering results were compared to standard optical emission spectral analyses of N2(C3Πu - B3Πg) bands, where the calculated rotational temperatures from emission were in reasonable agreement with the Rayleigh translational temperature profiles.
Thin Film Growth Of Dielectric Materials By Pulsed Laser Deposition, Jason Christopher Anders
Thin Film Growth Of Dielectric Materials By Pulsed Laser Deposition, Jason Christopher Anders
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Thin films of SryCa1-yZr1-xTixO3 (SCZT) with x = 0.8, y = 0.01, CaHf1-xTixO3 (CHT) with x = 0.8, and xBiScO3 - (1-x) BaTiO3 with x = 0.36 (BSBT(36/64)) showing a high permittivity are useful both in capacitor applications. These dielectric thin films with a SrRuO3 (SRO) conductive bottom electrodes were prepared by using pulsed laser deposition on <100< La0.3Sr0.7Al0.65Ta0.35O3 (LSAT) single crystal substrates. In a search of optimal conditions to achieve epitaxially grown SCZT, CHT, …
Thermal Properties Of Magnetic Nanoparticles In External Ac Magnetic Field, Anna Beata Lukawska
Thermal Properties Of Magnetic Nanoparticles In External Ac Magnetic Field, Anna Beata Lukawska
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This work studies thermal properties of magnetic nanoparticles in an external ac magnetic field. Dried iron and cobalt nanoparticles were prepared by thermal decomposition of iron pentacarbonyl (Fe(CO)5) and dicobalt octacarbonyl (Co2(CO)8), triscobalt nona(carbonyl)chloride (Co3(CO)9Cl), or tetracaobalt dodecacarbonyl (Co4(CO)12) [1]. The samples had different mean diameters: 5.6 - 21.4 nm for iron and 6.5 - 19.4 nm for cobalt. Each sample was exposed to ac magnetic field and the increase in temperature of the sample was measured. Results were analyzed to find the critical diameters for the transitions from multi-domain to single-domain and from single-domain to superparamagnetic regime. The nanoparticles …
Surface Effects On Critical Dimensions Of Ferromagnetic Nanoparticles, Vartika Chaudhary
Surface Effects On Critical Dimensions Of Ferromagnetic Nanoparticles, Vartika Chaudhary
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This work studies surface effects on the critical dimensions of ferromagnetic nanoparticles. Iron nanoparticles with different mean diameters from 5.9 nm to 21.4 nm used in this research were prepared by thermal decomposition of iron pentacarbonyl in the presence of oleic acid/octyl ether at Cambridge University, United Kingdom. Heating response of these ferromagnetic nanoparticles suspended in water were measured experimentally during which same amount of iron nanoparticles and di-ionized water were irradiated by an alternating magnetic field and the increase in temperature of these samples was measured. Heating performance of nanoparticles was described in terms of Specific Absorption Rate (SAR) …
Curie Temperature Measurement Of Ferromagnetic Nanoparticles By Using Calorimetry, Xing Zhao
Curie Temperature Measurement Of Ferromagnetic Nanoparticles By Using Calorimetry, Xing Zhao
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This Thesis studies the relationship between diameter (size) of ferromagnetic nanoparticles and Curie temperature. Iron nanoparticles with different diameters from 5.9 nm to 21.4 nm were prepared by thermal decomposition of iron pentacarbonyl in the presence of oleic acid/octyl ether at Cambridge University, United Kingdom. Heating response of these ferromagnetic nanoparticles suspended in water were measured experimentally during which the same amount of iron nanoparticles and di-ionized water were subjected to an alternating magnetic field and the increase in temperature of these samples was measured. Heating performance of nanoparticles was described by Specific Absorption Rate (SAR). Heating and cooling rate …
Chemical Analysis Of Exhaled Breath By Means Of Terahertz Rotational Spectroscopy, Tianle Guo
Chemical Analysis Of Exhaled Breath By Means Of Terahertz Rotational Spectroscopy, Tianle Guo
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Terahertz spectroscopy, due to the high sensitivity and specificity that it affords, has been incorporated in many fields to aid in the chemical analysis of gases. One potential application is to detect bio-markers in human breath for early diagnosis. Our current aim of our research is to establish a relationship between several chemicals and the glucose levels from human exhaled breath. 20 chemical including Acetone, Carbon monoxide (CO), Methanol were studied. Volunteers' breath samples were processed through a pre-concentration system before being injected into the spectrometer. Initially, a commercial preconcentration system, Entech 7100A, was used. However, due to the limitations …
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
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, Part 1
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 …
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
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, Part 1
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 …
Capturing And Modeling A Three-Dimensional Stationary Noise Source Directivity Pattern With A Dynamic Array In The Near Field, Randy Mieskoski
Capturing And Modeling A Three-Dimensional Stationary Noise Source Directivity Pattern With A Dynamic Array In The Near Field, Randy Mieskoski
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The author has studied several legacy landmark methodologies to develop an original measurement technique. Spherical harmonics modeling practices were leveraged to accurately represent a source directivity pattern. In this thesis a lightweight microphone measurement array that was manually maneuvered around a static noise source was employed. The measurement technique consisted of inserting a head-tracker sensor onto the microphone array to allow the location of the captured acoustic Sound Pressure Level (SPL) to be investigated. By leveraging the historical methodologies the acoustic SPL and location data collected with this technique were processes to represent a directivity pattern of the compressor source …
Electromagnetic Characterization Of Af455 With Dna-Ctma In Solvent Blends, Jessica Marie Hendricks
Electromagnetic Characterization Of Af455 With Dna-Ctma In Solvent Blends, Jessica Marie Hendricks
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This work studies the electromagnetic properties of AF455, a two photon dye, DNA bound with cetyltrimethyl ammonium (CTMA), in liquid solvent blends for use in thin film optical filters. The liquid properties of the materials are believed to be transferred to the films. The solvent blends used are ratios of toluene (T) and dimethyl sulfoxide (DMSO). The complex permittivity and permeability of the samples are measured using the short open coaxial line technique in the frequency range of 1.0 x 107 Hz to 2.0 x 109 Hz. In this frequency range, AF455 does not act as a two photon absorber. …