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Full-Text Articles in Physics
Toward Non-Invasive Measurement Of Atmospheric Temperature Using Vibro-Rotational Raman Spectra Of Diatomic Gases, Tyler Capek, Jacek Borysow, Claudio Mazzoleni, Massimo Moraldi
Toward Non-Invasive Measurement Of Atmospheric Temperature Using Vibro-Rotational Raman Spectra Of Diatomic Gases, Tyler Capek, Jacek Borysow, Claudio Mazzoleni, Massimo Moraldi
Michigan Tech Publications
We demonstrate precise determination of atmospheric temperature using vibro-rotational Raman (VRR) spectra of molecular nitrogen and oxygen in the range of 292–293 K. We used a continuous wave fiber laser operating at 10 W near 532 nm as an excitation source in conjunction with a multi-pass cell. First, we show that the approximation that nitrogen and oxygen molecules behave like rigid rotors leads to erroneous derivations of temperature values from VRR spectra. Then, we account for molecular non-rigidity and compare four different methods for the determination of air temperature. Each method requires no temperature calibration. The first method involves fitting …
Spatial And Temporal Variability Of Carbonaceous Aerosol Absorption In The Po Valley, Stefania Gilardoni, Paola Massoli, Angela Marinoni, Claudio Mazzoleni, Andrew Freedman, Giovanni Lonati, Silvana De Iuliis, Vorne Gianelle
Spatial And Temporal Variability Of Carbonaceous Aerosol Absorption In The Po Valley, Stefania Gilardoni, Paola Massoli, Angela Marinoni, Claudio Mazzoleni, Andrew Freedman, Giovanni Lonati, Silvana De Iuliis, Vorne Gianelle
Michigan Tech Publications
Knowledge gaps in the optical properties of carbonaceous aerosols account for a significant fraction of the uncertainty of aerosol-light interactions in climate models. Both black carbon (BC) and brown carbon (BrC) can display a range of optical properties in ambient aerosol due to different sources and chemical transformation pathways. This study investigates the optical absorption properties of BC and BrC at an urban and a rural site in the Po Valley (Italy), a known European pollution hot spot. We observed spatial and seasonal variability of aerosol absorption coefficients, with the highest values measured in winter at the urban site of …
All-Dielectric Magnetic Metasurface For Advanced Light Control In Dual Polarizations Combined With High-Q Resonances, Daria O. Ignatyeva, Dolendra Karki, Andrey A. Voronov, Mikhail A. Kozhaev, Denis M. Krichevsky, Alexander I. Chernov, Miguel Levy, Vladimir I. Belotelov
All-Dielectric Magnetic Metasurface For Advanced Light Control In Dual Polarizations Combined With High-Q Resonances, Daria O. Ignatyeva, Dolendra Karki, Andrey A. Voronov, Mikhail A. Kozhaev, Denis M. Krichevsky, Alexander I. Chernov, Miguel Levy, Vladimir I. Belotelov
Michigan Tech Publications
Nanostructured magnetic materials provide an efficient tool for light manipulation on sub-nanosecond and sub-micron scales, and allow for the observation of the novel effects which are fundamentally impossible in smooth films. For many cases of practical importance, it is vital to observe the magneto-optical intensity modulation in a dual-polarization regime. However, the nanostructures reported on up to date usually utilize a transverse Kerr effect and thus provide light modulation only for p-polarized light. We present a concept of a transparent magnetic metasurface to solve this problem, and demonstrate a novel mechanism for magneto-optical modulation. A 2D array of bismuth-substituted iron-garnet …
Reconstruction Of Events Recorded With The Surface Detector Of The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.
Reconstruction Of Events Recorded With The Surface Detector Of The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.
Michigan Tech Publications
Cosmic rays arriving at Earth collide with the upper parts of the atmosphere, thereby inducing extensive air showers. When secondary particles from the cascade arrive at the ground, they are measured by surface detector arrays. We describe the methods applied to the measurements of the surface detector of the Pierre Auger Observatory to reconstruct events with zenith angles less than 60 using the timing and signal information recorded using the water-Cherenkov detector stations. In addition, we assess the accuracy of these methods in reconstructing the arrival directions of the primary cosmic ray particles and the sizes of the induced showers.
Diel Cycle Of Sea Spray Aerosol Concentration Over Vast Areas Of The Tropical Pacific Ocean And The Caribbean Sea, J. Michel Flores, Guillaume Bourdin, A. Kostinski, Orit Altaratz, Guy Dagan, Fabien Lombard, Et. Al.
Diel Cycle Of Sea Spray Aerosol Concentration Over Vast Areas Of The Tropical Pacific Ocean And The Caribbean Sea, J. Michel Flores, Guillaume Bourdin, A. Kostinski, Orit Altaratz, Guy Dagan, Fabien Lombard, Et. Al.
Michigan Tech Publications
Ocean-atmosphere interactions such as sea spray aerosol (SSA) formation have a major role in the climate system, but a global-scale assessment of this micro-scale process is highly challenging. We measured high-resolution temporal patterns of SSA number concentration over the Atlantic Ocean, Caribbean Sea, and the Pacific Ocean covering 42,000 km of open ocean waters. We discovered a ubiquitous 24-hour rhythm to the number concentration, clearly seen for particle diameters > ~ 0.58 µm, with spikes at dawn and drops at dusk throughout the Pacific Ocean and Caribbean Sea, showing more than doubling of the SSA number concentration during the day than …
Features Of The Energy Spectrum Of Cosmic Rays Above 2.5 × 10 18 Ev Using The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.
Features Of The Energy Spectrum Of Cosmic Rays Above 2.5 × 10 18 Ev Using The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.
Michigan Tech Publications
We report a measurement of the energy spectrum of cosmic rays above 2.5×1018 eV based on 215 030 events. New results are presented: at about 1.3×1019 eV, the spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving to 5.1±0.3(stat)±0.1(syst) beyond 5×1019 eV, while no significant dependence of spectral features on the declination is seen in the accessible range. These features of the spectrum can be reproduced in models with energy-dependent mass composition. The energy density in cosmic rays above 5×1018 eV is [5.66±0.03(stat)±1.40(syst)]×1053 erg Mpc−3.
Measurement Of The Cosmic-Ray Energy Spectrum Above 2.5×1018 Ev Using The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.
Measurement Of The Cosmic-Ray Energy Spectrum Above 2.5×1018 Ev Using The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.
Michigan Tech Publications
We report a measurement of the energy spectrum of cosmic rays for energies above 2.5×1018 eV based on 215,030 events recorded with zenith angles below 60°. A key feature of the work is that the estimates of the energies are independent of assumptions about the unknown hadronic physics or of the primary mass composition. The measurement is the most precise made hitherto with the accumulated exposure being so large that the measurements of the flux are dominated by systematic uncertainties except at energies above 5×1019 eV. The principal conclusions are(1) The flattening of the spectrum near 5×1018 eV, the so-called …
Refinements To Data Acquired By 2-Dimensional Video Disdrometers, Michael L. Larsen, Christopher K. Blouin
Refinements To Data Acquired By 2-Dimensional Video Disdrometers, Michael L. Larsen, Christopher K. Blouin
Michigan Tech Publications
The 2-Dimensional Video Disdrometer (2DVD) is a commonly used tool for exploring rain microphysics and for validating remotely sensed rain retrievals. Recent work has revealed a persistent anomaly in 2DVD data. Early investigations of this anomaly concluded that the resulting errors in rain measurement were modest, but the methods used to flag anomalous data were not optimized, and related considerations associated with the sample sensing area were not fully investigated. Here, we (i) refine the anomaly-detecting algorithm for increased sensitivity and reliability and (ii) develop a related algorithm for refining the estimate of sample sensing area for all detected drops, …
Direct Measurement Of The Muonic Content Of Extensive Air Showers Between 2× 1017 And 2×1018 Ev At The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P. R. Araújo Ferreira, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R. J. Barreira Luz, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann, T. Bister, J. Biteau, A. Blanco, J. Blazek, B. Fick, D. F. Nitz, A. Puyleart
Direct Measurement Of The Muonic Content Of Extensive Air Showers Between 2× 1017 And 2×1018 Ev At The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P. R. Araújo Ferreira, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R. J. Barreira Luz, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann, T. Bister, J. Biteau, A. Blanco, J. Blazek, B. Fick, D. F. Nitz, A. Puyleart
Michigan Tech Publications
The hybrid design of the Pierre Auger Observatory allows for the measurement of the properties of extensive air showers initiated by ultra-high energy cosmic rays with unprecedented precision. By using an array of prototype underground muon detectors, we have performed the first direct measurement, by the Auger Collaboration, of the muon content of air showers between 2 × 10 17 and 2 × 10 18 eV. We have studied the energy evolution of the attenuation-corrected muon density, and compared it to predictions from air shower simulations. The observed densities are found to be larger than those predicted by models. We …
Light Scattering In A Turbulent Cloud: Simulations To Explore Cloud-Chamber Experiments, Corey D. Packard, Michael L. Larsen, Subin Thomas, Will H. Cantrell, Raymond A. Shaw
Light Scattering In A Turbulent Cloud: Simulations To Explore Cloud-Chamber Experiments, Corey D. Packard, Michael L. Larsen, Subin Thomas, Will H. Cantrell, Raymond A. Shaw
Michigan Tech Publications
Radiative transfer through clouds can be impacted by variations in particle number size distribution, but also in particle spatial distribution. Due to turbulent mixing and inertial effects, spatial correlations often exist, even on scales reaching the cloud droplet separation distance. The resulting clusters and voids within the droplet field can lead to deviations from exponential extinction. Prior work has numerically investigated these departures from exponential attenuation in absorptive and scattering media; this work takes a step towards determining the feasibility of detecting departures from exponential behavior due to spatial correlation in turbulent clouds generated in a laboratory setting. Large Eddy …
Secular Changes In Atmospheric Turbidity Over Iraq And A Possible Link To Military Activity, Alexandra Chudnovsky, A. Kostinski
Secular Changes In Atmospheric Turbidity Over Iraq And A Possible Link To Military Activity, Alexandra Chudnovsky, A. Kostinski
Michigan Tech Publications
We examine satellite-derived aerosol optical depth (AOD) data during the period 2000-2018 over the Middle East to evaluate the contribution of anthropogenic pollution. We focus on Iraq, where US troops were present for nearly nine years. We begin with a plausibility argument linking anthropogenic influence and AOD signature. We then calculate the percent change in AOD every two years. To pinpoint the causes for changes in AOD on a spatial basis, we distinguish between synoptically "calm" periods and those with vigorous synoptic activity. This was done on high-resolution 10 km AOD retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor …
Richardsite, Zn2cugas4, A New Gallium-Essential Member Of The Stannite Group From The Gem Mines Near Merelani, Tanzania, Luca Bindi, John A. Jaszczak
Richardsite, Zn2cugas4, A New Gallium-Essential Member Of The Stannite Group From The Gem Mines Near Merelani, Tanzania, Luca Bindi, John A. Jaszczak
Michigan Tech Publications
The new mineral richardsite occurs as overgrowths of small (50–400 μm) dark gray, disphenoidal crystals with no evident twinning, but epitaxically oriented on wurtzite–sphalerite crystals from the gem mines near Merelani, Lelatema Mountains, Simanjiro District, Manyara Region, Tanzania. Associated minerals also include graphite, diopside, and Ge,Ga-rich wurtzite. It is brittle, dark gray in color, and has a metallic luster. It appears dark bluish gray in reflected plane-polarized light, and is moderately bireflectant. It is distinctly anisotropic with violet to light-blue rotation tints with crossed polarizers. Reflectance percentages for Rmin and Rmax in air at the respective wavelengths are 23.5, 25.0 …
Characterization And First Results From Lacis-T: A Moist-Air Wind Tunnel To Study Aerosol-Cloud-Turbulence Interactions, Dennis Niedermeier, Jens Voigtländer, Silvio Schmalfuß, Daniel Busch, Jörg Schumacher, Raymond A. Shaw, Frank Stratmann
Characterization And First Results From Lacis-T: A Moist-Air Wind Tunnel To Study Aerosol-Cloud-Turbulence Interactions, Dennis Niedermeier, Jens Voigtländer, Silvio Schmalfuß, Daniel Busch, Jörg Schumacher, Raymond A. Shaw, Frank Stratmann
Michigan Tech Publications
The interactions between turbulence and cloud microphysical processes have been investigated primarily through numerical simulation and field measurements over the last 10 years. However, only in the laboratory we can be confident in our knowledge of initial and boundary conditions and are able to measure under statistically stationary and repeatable conditions. In the scope of this paper, we present a unique turbulent moist-air wind tunnel, called the Turbulent Leipzig Aerosol Cloud Interaction Simulator (LACIS-T) which has been developed at TROPOS in order to study cloud physical processes in general and interactions between turbulence and cloud microphysical processes in particular. The …
Constraining The Local Burst Rate Density Of Primordial Black Holes With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, H. A.Ayala Solares, V. Baghmanyan, E. Belmont-Moreno, S. Y. Benzvi, C. Brisbois, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, U. Cotti, J. Cotzomi, E. De La Fuente, C. De León, B. L. Dingus, M. A. Duvernois, J. C. Díaz-Vélez, R. W. Ellsworth, K. L. Engel, C. Espinoza, H. Fleischhack, N. Fraija, A. Galván-Gámez, J. A. García-González, F. Garfias, M. M. González, J. A. Goodman, B. Hona, D. Huang, Petra Huentemeyer
Constraining The Local Burst Rate Density Of Primordial Black Holes With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, H. A.Ayala Solares, V. Baghmanyan, E. Belmont-Moreno, S. Y. Benzvi, C. Brisbois, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, U. Cotti, J. Cotzomi, E. De La Fuente, C. De León, B. L. Dingus, M. A. Duvernois, J. C. Díaz-Vélez, R. W. Ellsworth, K. L. Engel, C. Espinoza, H. Fleischhack, N. Fraija, A. Galván-Gámez, J. A. García-González, F. Garfias, M. M. González, J. A. Goodman, B. Hona, D. Huang, Petra Huentemeyer
Michigan Tech Publications
Primordial Black Holes (PBHs) may have been created by density fluctuations in the early Universe and could be as massive as > 109 solar masses or as small as the Planck mass. It has been postulated that a black hole has a temperature inversely-proportional to its mass and will thermally emit all species of fundamental particles via Hawking Radiation. PBHs with initial masses of ∼ 5 × 1014 g (approximately one gigaton) should be expiring today with bursts of high-energy gamma radiation in the GeV-TeV energy range. The High Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays with energies …
A 3-Year Sample Of Almost 1,600 Elves Recorded Above South America By The Pierre Auger Cosmic-Ray Observatory, A. Aab, P. Abreu, M. Aglietta, I. F.M. Albuquerque, J. M. Albury, I. Allekotte, David Nitz, Et. Al.
A 3-Year Sample Of Almost 1,600 Elves Recorded Above South America By The Pierre Auger Cosmic-Ray Observatory, A. Aab, P. Abreu, M. Aglietta, I. F.M. Albuquerque, J. M. Albury, I. Allekotte, David Nitz, Et. Al.
Michigan Tech Publications
©2020. The Authors. Elves are a class of transient luminous events, with a radial extent typically greater than 250 km, that occur in the lower ionosphere above strong electrical storms. We report the observation of 1,598 elves, from 2014 to 2016, recorded with unprecedented time resolution (100 ns) using the fluorescence detector (FD) of the Pierre Auger Cosmic-Ray Observatory. The Auger Observatory is located in the Mendoza province of Argentina with a viewing footprint for elve observations of 3.106 km2, reaching areas above the Pacific and Atlantic Oceans, as well as the Córdoba region, which is known for severe convective …
Coherent Virtual Absorption Of Light In Microring Resonators, Q. Zhong, L. Simonson, T. Kottos, Ramy El-Ganainy
Coherent Virtual Absorption Of Light In Microring Resonators, Q. Zhong, L. Simonson, T. Kottos, Ramy El-Ganainy
Michigan Tech Publications
Light trapping and radiation process from linear reciprocal photonic resonators is one of the fundamental processes in optical science and engineering. Recently, the concept of coherent virtual absorption (CVA) of light was introduced and investigated for planar and cylindrical optical structures. The key feature of CVA is that by engineering the time dependence of the excitation waveform, one can temporarily store all the input energy in the optical structure without any leakage. Here we further explore this concept in integrated photonic setups made of microring resonators. By using coupled-mode theory, we derive an analytical expression for CVA in this platform. …
Phase Diagrams Of Polymer-Containing Liquid Mixtures With A Theory-Embedded Neural Network, Issei Nakamura
Phase Diagrams Of Polymer-Containing Liquid Mixtures With A Theory-Embedded Neural Network, Issei Nakamura
Michigan Tech Publications
We develop a deep neural network (DNN) that accounts for the phase behaviors of polymer-containing liquid mixtures. The key component in the DNN consists of a theory-embedded layer that captures the characteristic features of the phase behavior via coarse-grained mean-field theory and scaling laws and substantially enhances the accuracy of the DNN. Moreover, this layer enables us to reduce the size of the DNN for the phase diagrams of the mixtures. This study also presents the predictive power of the DNN for the phase behaviors of polymer solutions and salt-free and salt-doped diblock copolymer melts.
Radiative Absorption Enhancements By Black Carbon Controlled By Particle-To-Particle Heterogeneity In Composition, Laura Fierce, Timothy B. Onasch, Christopher D. Cappa, Claudio Mazzoleni, Swarup China, Janarjan Bhandari, Et Al.
Radiative Absorption Enhancements By Black Carbon Controlled By Particle-To-Particle Heterogeneity In Composition, Laura Fierce, Timothy B. Onasch, Christopher D. Cappa, Claudio Mazzoleni, Swarup China, Janarjan Bhandari, Et Al.
Michigan Tech Publications
Black carbon (BC) absorbs solar radiation, leading to a strong but uncertain warming effect on climate. A key challenge in modeling and quantifying BC’s radiative effect on climate is predicting enhancements in light absorption that result from internal mixing between BC and other aerosol components. Modeling and laboratory studies show that BC, when mixed with other aerosol components, absorbs more strongly than pure, uncoated BC; however, some ambient observations suggest more variable and weaker absorption enhancement. We show that the lower-than-expected enhancements in ambient measurements result from a combination of two factors. First, the often used spherical, concentric core-shell approximation …
Acoustics To Quantum Materials: A Centennial History Of The Department Of Physics, University Of Arkansas, Rajendra Gupta, Paul C. Sharrah
Acoustics To Quantum Materials: A Centennial History Of The Department Of Physics, University Of Arkansas, Rajendra Gupta, Paul C. Sharrah
Physics Faculty Publications and Presentations
The department of physics at the University of Arkansas was established in the 1907-08 academic year, although physics was taught from the very start of the University in 1872. The department celebrated its centennial in 2007-2008. Acoustics to Quantum Materials is a centennial history of the department covering the period 1907-08 to 2007-08. While the emphasis is on this period, instruction of physics over the period 1872-1907 is covered in two prologues, and the period 2009-18 is briefly covered in an epilogue. The first research laboratory to be established was in the area of acoustics. Subsequently, the department’s faculty have …
Consciousness As A Factor In Evolution, Kenneth A. Augustyn
Consciousness As A Factor In Evolution, Kenneth A. Augustyn
Michigan Tech Publications
What I call the mind began as a non-conscious robotic biochemical process control system in the very earliest forms of life. As life evolved, problems in control became more difficult and exceeded the computational capabilities of the organisms. Nature discovered a means of transcending computable physical processes resulting in non-computational subjective mental capabilities that, while still not conscious, had a degree of genuine autonomy from the physical world. These autonomous subjective wants and goals now affected the course of (but not the mechanism of) evolution. The integrated amalgam of robotic and transrobotic unconscious capabilities eventually gave rise to consciousness, which …
Special Issue On The Third Workshop On Biological Mentality, Kenneth A. Augustyn
Special Issue On The Third Workshop On Biological Mentality, Kenneth A. Augustyn
Michigan Tech Publications
The Third Workshop on Biological Mentality was held from September 23, 2019 to March 2, 2020 as a series of twenty-one Monday online conferencing sessions, each consisting of a talk followed by a Q&A discussion. Like the two previous workshops [1, 2], the objective of this workshop was to seek a deeper level of understanding the physical foundations of biological mentality (whether conscious or nonconscious).