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Articles 1 - 30 of 238

Full-Text Articles in Physics

Data Supporting The Paper "The Role Of Turbulent Fluctuations In Aerosol Activation And Cloud Formation", Prasanth Prabhakaran, Abu Sayeed Md Shawon, Greg Kinney, Subin Thomas, Will Cantrell, Raymond Shaw May 2020

Data Supporting The Paper "The Role Of Turbulent Fluctuations In Aerosol Activation And Cloud Formation", Prasanth Prabhakaran, Abu Sayeed Md Shawon, Greg Kinney, Subin Thomas, Will Cantrell, Raymond Shaw

Data Files

This data supports the following paper:

Prasanth Prabhakaran, Abu Sayeed Md Shawon, Gregory Kinney, Subin Thomas, Will Cantrell and Raymond A. Shaw, “The role of turbulent fluctuations in aerosol activation and cloud formation”, Proceedings of the National Academy of Sciences (2020), in review.


Secular Changes In Atmospheric Turbidity Over Iraq And A Possible Link To Military Activity, Alexandra Chudnovsky, A. Kostinski May 2020

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 May 2020

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 ...


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. Jan 2020

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 ...


Phase Diagrams Of Polymer-Containing Liquid Mixtures With A Theory-Embedded Neural Network, Issei Nakamura Jan 2020

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.


Optical Dispersion Relations From Three-Dimensional Chiral Gold Nanocubes In Periodic Arrays, Manpreet Boora Jan 2020

Optical Dispersion Relations From Three-Dimensional Chiral Gold Nanocubes In Periodic Arrays, Manpreet Boora

Dissertations, Master's Theses and Master's Reports

Chiral metamaterials are artificially tailored materials that are composed of nanoparticles that lack in-plane mirror symmetry. Application of chirality to plasmonic nanostructures can lead to chiro-optical effects such as asymmetric transmission of circularly polarized light, circular dichroism and optical activity. When light is incident on metallic nanoparticles, conduction electrons undergo collective oscillations within the nanoparticles, resulting in localized surface plasmon (LSP) resonance. Surface lattice resonances (SLRs) are hybrid plasmonic-photonic modes arising from the radiative coupling between LSPs and electromagnetic waves diffracted in the plane of the periodic array. Because of the collective dipole interactions, SLRs have less radiative losses compared ...


Is Contact Nucleation Caused By Pressure Perturbation?, Fan Yang, Will Cantrell, Alexander Kostinski, Raymond Shaw, Andrew M. Vogelmann Dec 2019

Is Contact Nucleation Caused By Pressure Perturbation?, Fan Yang, Will Cantrell, Alexander Kostinski, Raymond Shaw, Andrew M. Vogelmann

Michigan Tech Publications

The reason why ice nucleation is more efficient by contact nucleation than by immersion nucleation has been elusive for over half a century. Six proposed mechanisms are summarized in this study. Among them, the pressure perturbation hypothesis, which arose from recent experiments, can qualitatively explain nearly all existing results relevant to contact nucleation. To explore the plausibility of this hypothesis in a more quantitative fashion and to guide future investigations, this study assessed the magnitude of pressure perturbation needed to cause contact nucleation and the associated spatial scales. The pressure perturbations needed were estimated using measured contact nucleation efficiencies for ...


Laboratory Study Of The Heterogeneous Ice Nucleation On Black-Carbon-Containing Aerosol, Leonid Nichman, Martin Wolf, Paul Davidovits, Timothy Onasch, Yue Zhang, Doug Worsnop, Janarjan Bhandari, Claudio Mazzoleni, Daniel Cziczo Oct 2019

Laboratory Study Of The Heterogeneous Ice Nucleation On Black-Carbon-Containing Aerosol, Leonid Nichman, Martin Wolf, Paul Davidovits, Timothy Onasch, Yue Zhang, Doug Worsnop, Janarjan Bhandari, Claudio Mazzoleni, Daniel Cziczo

Michigan Tech Publications

Soot and black carbon (BC) particles are generated in the incomplete combustion of fossil fuels, biomass, and biofuels. These airborne particles affect air quality, human health, aerosol–cloud interactions, precipitation formation, and climate. At present, the climate effects of BC particles are not well understood. Their role in cloud formation is obscured by their chemical and physical variability and by the internal mixing states of these particles with other compounds. Ice nucleation in field studies is often difficult to interpret. Nonetheless, most field studies seem to suggest that BC particles are not efficient ice-nucleating particles (INPs). On the other hand ...


Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni Aug 2019

Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni

Michigan Tech Publications

Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after ...


Astro2020 Apc White Paper: Elevating The Role Of Software As A Product Of The Research Enterprise, Arfon Smith, Dara Norman, Kelle Cruz, Vandana Desai, Eric Bellm, Robert J. Nemiroff, Et. Al. Jul 2019

Astro2020 Apc White Paper: Elevating The Role Of Software As A Product Of The Research Enterprise, Arfon Smith, Dara Norman, Kelle Cruz, Vandana Desai, Eric Bellm, Robert J. Nemiroff, Et. Al.

Michigan Tech Publications

Software is a critical part of modern research, and yet there are insufficient mechanisms in the scholarly ecosystem to acknowledge, cite, and measure the impact of research software. The majority of academic fields rely on a one-dimensional credit model whereby academic articles (and their associated citations) are the dominant factor in the success of a researcher's career. In the petabyte era of astronomical science, citing software and measuring its impact enables academia to retain and reward researchers that make significant software contributions. These highly skilled researchers must be retained to maximize the scientific return from petabyte-scale datasets. Evolving beyond ...


Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber, Subin Thomas, Mikhail Ovichinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw Jul 2019

Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber, Subin Thomas, Mikhail Ovichinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw

Michigan Tech Publications

The Pi Cloud Chamber offers a unique opportunity to study aerosol-cloud microphysics interactions in a steady-state, turbulent environment. In this work, an atmospheric large-eddy simulation (LES) model with spectral bin microphysics is scaled down to simulate these interactions, allowing comparison with experimental results. A simple scalar flux budget model is developed and used to explore the effect of sidewalls on the bulk mixing temperature, water vapor mixing ratio, and supersaturation. The scaled simulation and the simple scalar flux budget model produce comparable bulk mixing scalar values. The LES dynamics results are compared with particle image velocimetry measurements of turbulent kinetic ...


Searching For Dark Matter Sub-Structure With Hawc, A. U. Abeysekara, A. Albert, R. Alfaro, C. Alvarez, R. Arceo, J. C. Arteaga-Valazquez, Chad Brisbois, H. Fleischhack, Binita Hona, P. Huntemeyer, Et Al. Jul 2019

Searching For Dark Matter Sub-Structure With Hawc, A. U. Abeysekara, A. Albert, R. Alfaro, C. Alvarez, R. Arceo, J. C. Arteaga-Valazquez, Chad Brisbois, H. Fleischhack, Binita Hona, P. Huntemeyer, Et Al.

Michigan Tech Publications

Numerical simulations show that the dark matter halos surrounding galaxies are expected to contain many over-densities or sub-halos. The most massive of these sub-halos can be optically observed in the form of dwarf galaxies. However, most lower mass sub-halos are predicted to exist as dark dwarf galaxies: sub-halos like dwarf galaxies with no luminous counterpart. It may be possible to detect these unseen sub-halos from gamma-ray signals originating from dark matter annihilation. The High Altitude Water Cherenkov Observatory (HAWC) is a very high energy (500 GeV to >100 TeV) gamma ray detector with a wide field-of-view and near continuous duty ...


Data Supporting The Paper "Aerosol Mediated Glaciation Of Mixed-Phase Clouds: Steady-State Laboratory Measurements", N. Desai, K. K. Chandrakar, G. Kinney, W. Cantrell, R. A. Shaw Jun 2019

Data Supporting The Paper "Aerosol Mediated Glaciation Of Mixed-Phase Clouds: Steady-State Laboratory Measurements", N. Desai, K. K. Chandrakar, G. Kinney, W. Cantrell, R. A. Shaw

Department of Physics Publications

No abstract provided.


Tailoring Of The Electronic Property Of Zn-Btc Metal–Organic Framework Via Ligand Functionalization: An Ab Initio Investigation, Gemechis Degaga, Ravindra Pandey, Chansi Gupta, Lalit Bharadwaj May 2019

Tailoring Of The Electronic Property Of Zn-Btc Metal–Organic Framework Via Ligand Functionalization: An Ab Initio Investigation, Gemechis Degaga, Ravindra Pandey, Chansi Gupta, Lalit Bharadwaj

Department of Physics Publications

Metal–organic frameworks (MOFs) are porous materials of recent interest due to their promising properties for technological applications. In this paper, the structure–property relationships of pristine and functionalized Zn-BTC (Zn3(BTC)2) MOFs are investigated. The results based on density functional theory (DFT) find that MOFs with coordinatively saturated secondary building units (SBU) are metallic, and MOFs with coordinatively unsaturated SBU are semi-conducting. The ligand functionalization with electron acceptor (cyano-) and electron donor (amino-) groups appears to tailor the electronic properties of Zn-BTC MOFs; amino-functionalization led to a significant upward shift of the band-edges whereas cyano-functionalization ...


Turbulence-Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz Apr 2019

Turbulence-Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz

Michigan Tech Publications

The phenomenon of “cloud voids”, i.e., elongated volumes inside a cloud that are devoid of droplets, was observed with laser sheet photography in clouds at a mountain-top station. Two experimental cases, similar in turbulence conditions yet with diverse droplet size distributions and cloud void prevalence, are reported. A theoretical explanation is proposed based on the study of heavy inertial sedimenting particles inside a Burgers vortex. A general conclusion regarding void appearance is drawn from theoretical analysis. Numerical simulations of polydisperse droplet motion with realistic vortex parameters and Mie scattering visual effects accounted for can explain the presence of voids ...


Leidenfrost Pattern Formation And Boiling, Prasanth Prabhakaran, Alexei Krekhov, Eberhard Bodenschatz, Stephan Weiss Apr 2019

Leidenfrost Pattern Formation And Boiling, Prasanth Prabhakaran, Alexei Krekhov, Eberhard Bodenschatz, Stephan Weiss

Department of Physics Publications

We report on Leidenfrost patterns and boiling with compressed sulfur hexafluoride ( SF6). The experiments were carried out in a large aspect ratio Rayleigh–Bénard convection cell, where the distance between the horizontal plates is comparable with the capillary length of the working fluid. Pressures and temperatures were chosen such that the bottom plate was above and the top plate was below the liquid–vapor transition temperature of SF6. As a result, SF6 vapor condenses at the top plate and forms drops that grow in size. Leidenfrost patterns are formed as the drops do not fall but levitate ...


The Dawn Of Non-Hermitian Optics, Ramy El-Ganainy, Mercedeh Khajavikhan, Demetrios Christodoulides, Sahin Ozdemir Mar 2019

The Dawn Of Non-Hermitian Optics, Ramy El-Ganainy, Mercedeh Khajavikhan, Demetrios Christodoulides, Sahin Ozdemir

Department of Physics Publications

Recent years have seen a tremendous progress in the theory and experimental implementations of non-Hermitian photonics, including all-lossy optical systems as well as parity-time symmetric systems consisting of both optical loss and gain. This progress has led to a host of new intriguing results in the physics of light–matter interactions with promising potential applications in optical sciences and engineering. In this comment, we present a brief perspective on the developments in this field and discuss possible future research directions that can benefit from the notion of non-Hermitian engineering.


Data Supporting The Paper "Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations", Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn R. Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra Dubey, Allison Aiken, Rajan K. Chakrabarty, Hans Moosmüller, Timothy B. Onasch, Rahul A. Zaveri, Barbara Scarnato, Paolo Fialho, Claudio Mazzoleni Feb 2019

Data Supporting The Paper "Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations", Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn R. Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra Dubey, Allison Aiken, Rajan K. Chakrabarty, Hans Moosmüller, Timothy B. Onasch, Rahul A. Zaveri, Barbara Scarnato, Paolo Fialho, Claudio Mazzoleni

Department of Physics Publications

No abstract provided.


Natural Graphite Cuboids, Andrey Korsakov, Olga V. Rezvukhina, John Jaszczak, Dmitriy I. Rezvukhin, Denis Mikhailenko Feb 2019

Natural Graphite Cuboids, Andrey Korsakov, Olga V. Rezvukhina, John Jaszczak, Dmitriy I. Rezvukhin, Denis Mikhailenko

Department of Physics Publications

Graphite cuboids are abundant in ultrahigh-pressure metamorphic rocks and are generally interpreted as products of partial or complete graphitization of pre-existing diamonds. The understanding of the graphite cuboid structure and its formation mechanisms is still very limited compared to nanotubes, cones, and other carbon morphologies. This paper is devoted to the natural occurrences of graphite cuboids in several metamorphic and magmatic rocks, including diamondiferous metamorphic assemblages. The studied cuboids are polycrystalline aggregates composed either of numerous smaller graphite cuboids with smooth surfaces or graphite flakes radiating from a common center. Silicates, oxides, and sulphides are abundant in all the samples ...


Data Supporting The Paper "Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber", Subin Thomas, Mikhail S. Ovchinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw Feb 2019

Data Supporting The Paper "Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber", Subin Thomas, Mikhail S. Ovchinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw

Department of Physics Publications

No abstract provided.


Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar Jan 2019

Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar

Dissertations, Master's Theses and Master's Reports

Coherent light - such as that from a laser - on interaction with biological tissues, undergoes scattering. This scattered light undergoes interference and the resultant field has randomly added phases and amplitudes. This random interference pattern is known as speckles, and has been the subject of multiple applications, including imaging techniques. These speckle fields inherently contain optical vortices, or phase singularities. These are locations where the intensity (or amplitude) of the interference pattern is zero, and the phase is undefined.

In the research presented in this dissertation, dynamic speckle patterns were obtained through computer simulations as well as laboratory setups involving scattering ...


Energy Transfer Between Eu2+ And Mn2+ For Na(Sr,Ba)Po4 And Ba2mg(Bo3)2, Kevin Bertschinger Jan 2019

Energy Transfer Between Eu2+ And Mn2+ For Na(Sr,Ba)Po4 And Ba2mg(Bo3)2, Kevin Bertschinger

Dissertations, Master's Theses and Master's Reports

There is no debate of the affect that solid-state lighting has had on the world we live in. Throughout the centuries, lighting has continued to improve from kerosene lanterns to white light emitting diodes. Even though lighting today is sufficient there is still much room to improve color rendering index and efficiency. An active area of research to improve today's lighting technology is by doping inorganic phosphors with luminescent ion centers. There have been numerous reports of inorganic phosphors showing a variety of emission color and luminescence. In this thesis we discuss two new inorganic phosphors codoped with Eu ...


Optimization And Control Of Arrays Of Wave Energy Converters, Jianyang Lyu Jan 2019

Optimization And Control Of Arrays Of Wave Energy Converters, Jianyang Lyu

Dissertations, Master's Theses and Master's Reports

Wave Energy Converter Array is a practical approach to harvest ocean wave energy. To leverage the potential of the WEC array in terms of energy extraction, it is essential to have a properly designed array configuration and control system. This thesis explores the optimal configuration of Wave Energy Converters (WECs) arrays and their optimal control. The optimization of the WEC array allows both dimensions of individual WECs as well as the array layout to varying. In the first optimization problem, cylindrical buoys are assumed in the array where their radii and drafts are optimization parameters. Genetic Algorithms are used for ...


The Solvation Energy Of Ions In A Stockmayer Fluid, Cameron John Shock Jan 2019

The Solvation Energy Of Ions In A Stockmayer Fluid, Cameron John Shock

Dissertations, Master's Theses and Master's Reports

The solvation of ions in polar solvents has been a long studied system since the early twentieth century. A common technique to calculate the energy associated with ion solvation is the Born Solvation energy equation. This equation assumes an ion is placed in an incompressible, homogeneous dielectric, which is not necessarily representative of a real system. In this work the Stockmayer Fluid Model is used in a molecular dynamics simulation through the software LAMMPS to check the quantitative correctness of the Born equation. It is also shown how solvation energies of ions placed in polymerized and non-polymerized solvents differ. It ...


Physics And Applications Of Exceptional Points, Qi Zhong Jan 2019

Physics And Applications Of Exceptional Points, Qi Zhong

Dissertations, Master's Theses and Master's Reports

Exceptional points (EPs) are singularities that arise in non-Hermitian physics. Crossing EPs is believed to be related with phase transitions between parity-time-(PT-)symmetric phase and broken PT phase. Owing to their peculiar topology, EPs can remotely induce observable effects when encircled by closed trajectories in the parameter space. In this dissertation, first of all, we investigate the extreme dynamics of non-Hermitian systems near higher order EPs constructed using the bosonic algebra method. The strong power oscillations for certain initial conditions can occur as a result of the peculiar eigenspace geometry and its dimensionality collapse near these singularities. And in ...


Electron Spectrum Of The Dragonfly Pulsar Wind Nebula From X-Ray To Tev, Chad Brisbois, V. Joshi Jan 2019

Electron Spectrum Of The Dragonfly Pulsar Wind Nebula From X-Ray To Tev, Chad Brisbois, V. Joshi

Michigan Tech Publications

The Dragonfly nebula is a Vela-like Pulsar Wind Nebula (PWN) in the Cygnus region powered by the spin down of PSR J2021+3651. In X-rays, the inner nebula is a few arcseconds across, whereas at TeV energies VERITAS and HAWC has observed extended emission much larger than the extension in X-rays. The TeV gamma-ray source HAWC J2019+368 was originally discovered in 2007 by the Milagro Observatory and has been associated with this pulsar. Recent work has shown hints of energy dependent morphology for the source at TeV energies, supporting the interpretation of the gamma-ray emission being due to Inverse ...


Testing The Limits Of Particle Acceleration In Cygnus Ob2 With Hawc, Binita Hona, H. Fleischhack, Petra Huentemeyer Jan 2019

Testing The Limits Of Particle Acceleration In Cygnus Ob2 With Hawc, Binita Hona, H. Fleischhack, Petra Huentemeyer

Michigan Tech Publications

Star forming regions (SFRs) have been postulated as possible sources of cosmic rays (CRs) in our galaxy. One example of a gamma-ray source associated with an SFR is the Fermi-LAT cocoon, an extended region of gamma-ray emission in the Cygnus X region and attributed to a possible superbubble with freshly accelerated CRs. Because the emission region is surrounded by ionization fronts, it has been named the Cygnus cocoon. CRs in the cocoon could have originated in the OB2 association and been accelerated at the interaction sites of stellar winds of massive O type stars. So far, there is no clear ...


Aerosol-Cloud Interactions In Turbulent Clouds: A Combined Cloud Chamber And Theoretical Study, Kamal Kant Chandrakar Jan 2019

Aerosol-Cloud Interactions In Turbulent Clouds: A Combined Cloud Chamber And Theoretical Study, Kamal Kant Chandrakar

Dissertations, Master's Theses and Master's Reports

The influence of aerosol concentration on the cloud droplet size distribution is investigated in a laboratory chamber that enables turbulent cloud formation through moist convection. In chapter 2, moist Rayleigh-Bénard convection with water saturated boundaries is explored using a one-dimensional-turbulence model. This study provides some background about supersaturation statistics in moist convection. Chapters 3 - 7 discuss the experimental and theoretical investigation of aerosol-cloud interactions and cloud droplet size-distributions in turbulent conditions. The experiments are performed in a way so that steady-state microphysics are achieved, with aerosol input balanced by cloud droplet growth and fallout. As aerosol concentration is increased the ...


Light Propagation Through A Turbulent Cloud: Comparison Of Measured And Computed Extinction, Eduardo Rodriguez-Feo Bermudez Jan 2019

Light Propagation Through A Turbulent Cloud: Comparison Of Measured And Computed Extinction, Eduardo Rodriguez-Feo Bermudez

Dissertations, Master's Theses and Master's Reports

Remote sensing techniques used for measurement of atmospheric cloud properties operate under the notion that light extinction caused by scattering and absorption is exponential due to Beer-Lambert law. This is expected to be valid for a uni-form medium with no spatial correlations between particle position. The aim of this research was to show that under turbulent conditions, cloud droplets cannot be interpreted as non-correlated, and in turn will exhibit a lower than exponential light decay from scattering. The research took place at the MTU π-Chamber laboratory. A temperature difference between the floor and ceiling of the chamber was applied to ...


Physical Foundations Of Biological Mentality, Kenneth Augustyn Jan 2019

Physical Foundations Of Biological Mentality, Kenneth Augustyn

Michigan Tech Publications

Dualism struggles to connect two layers: the conscious mind and the physical workings of matter. It ignores a vast middle layer between the two, a layer that is beneath consciousness yet above known physical law. This middle layer is trans-robotic mentality, a means discovered by Nature to transcend robotic mentality. This middle layer evolved over billions of years before consciousness emerged from it, assuming more and more functions critical to survival as species evolved. Consciousness eventually emerged from trans-robotic mentality (not from robotic mentality), first intermittently then later more-or-less continuously. But there is no direct link between consciousness and matter ...