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Michigan Technological University

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2019

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Universal Rank-Order Transform To Extract Signals From Noisy Data, Glenn Ierley, Alexander Kostinski Sep 2019

Universal Rank-Order Transform To Extract Signals From Noisy Data, Glenn Ierley, Alexander Kostinski

Michigan Tech Publications

We introduce an ordinate method for noisy data analysis, based solely on rank information and thus insensitive to outliers. The method is nonparametric and objective, and the required data processing is parsimonious. The main ingredients include a rank-order data matrix and its transform to a stable form, which provide linear trends in excellent agreement with least squares regression, despite the loss of magnitude information. A group symmetry orthogonal decomposition of the 2D rank-order transform for iid (white) noise is further ordered by principal component analysis. This two-step procedure provides a noise “etalon” used to characterize arbitrary stationary stochastic processes. The …


Analysis Of An Updated Paleointensity Database (Qpi‐Pint) For 65–200 Ma: Implications For The Long‐Term History Of Dipole Moment Through The Mesozoic, E. V. Kulakov, C. J. Sprain, P. V. Doubrovine, A. V. Smirnov, G. A. Paterson, L. Hawkins, L. Fairchild, E. J. Piispa, A. J. Biggin Sep 2019

Analysis Of An Updated Paleointensity Database (Qpi‐Pint) For 65–200 Ma: Implications For The Long‐Term History Of Dipole Moment Through The Mesozoic, E. V. Kulakov, C. J. Sprain, P. V. Doubrovine, A. V. Smirnov, G. A. Paterson, L. Hawkins, L. Fairchild, E. J. Piispa, A. J. Biggin

Michigan Tech Publications

The global paleointensity database for 65–200 Ma was analyzed using a modified suite of paleointensity quality criteria (QPI) such that the likely reliability of measurements is assessed objectively and as consistently as possible across the diverse data set. This interval was chosen because of dramatic extremes of geomagnetic polarity reversal frequency ranging from greater than 10 reversals per million years in the Jurassic hyperactivity period (155–171 Ma) to effectively zero during the Cretaceous Normal Superchron (CNS; 84–126 Ma). Various attempts to establish a relationship between the strength of Earth's magnetic field and the reversal frequency have been made …


Me-Em Enewsbrief, September 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Sep 2019

Me-Em Enewsbrief, September 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical Engineering-Engineering Mechanics eNewsBrief

No abstract provided.


Revisiting "Home" In Ghanaian Poetry: Awoonor, Anyidoho And Adzei, Gabriel Edzordzi Agbozo Sep 2019

Revisiting "Home" In Ghanaian Poetry: Awoonor, Anyidoho And Adzei, Gabriel Edzordzi Agbozo

Michigan Tech Publications

The idea of “home” is a significant occurrence in postcolonial literature, as it connects to other ideas as identity, nationhood, and culture. This paper discusses “home” in Ghanaian poetry focusing on three well-regarded poets: Kofi Awoonor, Kofi Anyidoho, and Mawuli Adzei. These poets come from the Ewe ethnic group, and engage with the Pan-African project in both their scholarly and creative expressions. Drawing on John Berger, Sara Dessen, and Ewe thought on the afterlife, this paper suggests two major types of “home” in the works of these three poets: the physical, and the metaphysical. Physical “home” refer to the Wheta …


Detecting Dynamic System Regime Boundaries With Fisher Information: The Case Of Ecosystems, Eva Konig, Heriberto Cabezas, Audrey L. Mayer Sep 2019

Detecting Dynamic System Regime Boundaries With Fisher Information: The Case Of Ecosystems, Eva Konig, Heriberto Cabezas, Audrey L. Mayer

Michigan Tech Publications

The direct measurement of the resilience (resistance to disturbances) of an ecosystem’s current regime (or “alternative stable state”) remains a key concern for managing human impacts on these ecosystems and their risk of collapse. Approaches which utilize statistics or information theory have demonstrated utility in identifying regime boundaries. Here, we use Fisher information to establish the limits of the resilience of a dynamic regime of a predator–prey system. This is important because previous studies using Fisher information focused on detecting whether a regime change has occurred, whereas here we are interested in determining how much an ecological system can vary …


Low-Cost Open Source Ultrasound-Sensing Based Navigational Support For The Visually Impaired, Aliaksei Petsiuk, Joshua M. Pearce Aug 2019

Low-Cost Open Source Ultrasound-Sensing Based Navigational Support For The Visually Impaired, Aliaksei Petsiuk, Joshua M. Pearce

Michigan Tech Publications

Nineteen million Americans have significant vision loss. Over 70% of these are not employed full-time, and more than a quarter live below the poverty line. Globally, there are 36 million blind people, but less than half use white canes or more costly commercial sensory substitutions. The quality of life for visually impaired people is hampered by the resultant lack of independence. To help alleviate these challenges this study reports on the development of a low-cost, open-source ultrasound-based navigational support system in the form of a wearable bracelet to allow people with the lost vision to navigate, orient themselves in their …


Multiscale Collection And Analysis Of Submerged Aquatic Vegetation Spectral Profiles For Eurasian Watermilfoil Detection, Colin Brooks, Amanda Grimm, Amy Marcarelli, Richard Dobson Aug 2019

Multiscale Collection And Analysis Of Submerged Aquatic Vegetation Spectral Profiles For Eurasian Watermilfoil Detection, Colin Brooks, Amanda Grimm, Amy Marcarelli, Richard Dobson

Michigan Tech Publications

The ability to differentiate a non-native aquatic plant, Myriophyllum spicatum (Eurasian watermilfoil or EWM), from other submerged aquatic vegetation (SAV) using spectral data collected at multiple scales was investigated as a precursor to mapping of EWM. Spectral data were collected using spectroradiometers for SAV taken out of the water, from the side of a boat directly over areas of SAV and from a lightweight portable radiometer system flown from an unmanned aerial system (UAS). EWM was spectrally different from other SAV when using 651 spectral bands collected in ultraviolet to near-infrared range of 350 to 1000 nm but does not …


High-Temperature Performance Of Polymer-Modified Asphalt Mixes: Preliminary Evaluation Of The Usefulness Of Standard Technical Index In Polymer-Modified Asphalt., Kezhen Yan, Lingyun You, Daocheng Wang Aug 2019

High-Temperature Performance Of Polymer-Modified Asphalt Mixes: Preliminary Evaluation Of The Usefulness Of Standard Technical Index In Polymer-Modified Asphalt., Kezhen Yan, Lingyun You, Daocheng Wang

Michigan Tech Publications

The objectives of this study are to evaluate the high-temperature performance of polymer-modified asphalt and asphalt mixtures, and to investigate if the standard technical indexes are useful in the performance evaluation of the polymer-modified asphalt. There are four typically used polymer-modified asphalt types employed in the study. The standard high-temperature rheological test, such as the temperature sweep test, was used to express the high-temperature performance of the polymer-modified asphalt. Also, considering the non-Newtonian fluid properties of the polymer-modified asphalt, the multiple stress creep recovery (MSCR) and zero-shear viscosity (ZSV) tests were employed for the characterizations. Besides, based on the mixture …


Surface Water Microbial Community Response To The Biocide 2-2-Dibromo-3-Nitrilopropionamide Used In Unconventional Oil And Gas Extraction., Maria Fernanda Campa, Stephen Techtmann, Mallory P Ladd, Jun Yan, Megan Patterson, Amanda Garcia De Matos Amaral, Et. Al. Aug 2019

Surface Water Microbial Community Response To The Biocide 2-2-Dibromo-3-Nitrilopropionamide Used In Unconventional Oil And Gas Extraction., Maria Fernanda Campa, Stephen Techtmann, Mallory P Ladd, Jun Yan, Megan Patterson, Amanda Garcia De Matos Amaral, Et. Al.

Michigan Tech Publications

Production of unconventional oil and gas continues to rise, but the effects of high-density hydraulic fracturing (HF) activity near aquatic ecosystems are not fully understood. A commonly used biocide in HF, 2,2-dibromo-3-nitrilopropionamide (DBNPA), was studied in microcosms of HF-impacted vs. HF-unimpacted surface water streams to (1) compare the microbial community response, (2) investigate DBNPA degradation products based on past HF exposure, and (3) compare the microbial community response differences and similarities between the HF biocides DBNPA and glutaraldehyde. The microbial community responded to DBNPA differently in HF-impacted vs. HF-unimpacted microcosms in terms of 16S rRNA gene copies quantified, alpha and …


Observations Of Internal Waves Generated By An Anticyclonic Eddy: A Case Study In The Ice Edge Region Of The Greenland Sea, O. M. Johannessen, S. Sandven, I. P. Chunchuzov, R. A. Shuchman Aug 2019

Observations Of Internal Waves Generated By An Anticyclonic Eddy: A Case Study In The Ice Edge Region Of The Greenland Sea, O. M. Johannessen, S. Sandven, I. P. Chunchuzov, R. A. Shuchman

Michigan Tech Publications

Internal waves in the ocean play an important role in turbulence generation due to wave-breaking processes and mixing of the ocean. Airborne radar images of internal waves and ocean eddies north of Svalbard suggested that ocean eddies could generate internal waves. Here, we test this hypothesis using data from a dedicated internal wave experiment in the Greenland Sea. Internal waves with dominant frequencies of 1–3 cycles per hour and amplitudes up to 15 m were observed using three thermistor chains suspended from a drifting array conveniently placed on the ice in a triangle with sides of several km. Analysis shows …


Docking Control Of An Autonomous Underwater Vehicle Using Reinforcement Learning, Enrico Anderlini, Gordon Parker, Giles Thomas Aug 2019

Docking Control Of An Autonomous Underwater Vehicle Using Reinforcement Learning, Enrico Anderlini, Gordon Parker, Giles Thomas

Michigan Tech Publications

To achieve persistent systems in the future, autonomous underwater vehicles (AUVs) will need to autonomously dock onto a charging station. Here, reinforcement learning strategies were applied for the first time to control the docking of an AUV onto a fixed platform in a simulation environment. Two reinforcement learning schemes were investigated: one with continuous state and action spaces, deep deterministic policy gradient (DDPG), and one with continuous state but discrete action spaces, deep Q network (DQN). For DQN, the discrete actions were selected as step changes in the control input signals. The performance of the reinforcement learning strategies was compared …


Experimental Investigation Of The Effects Of Drilling Fluid Activity On The Hydration Behavior Of Shale Reservoirs In Northwestern Hunan, China, Han Cao, Zheng Zhang, Ting Bao, Pinghe Sun, Tianyi Wang, Qiang Gao Aug 2019

Experimental Investigation Of The Effects Of Drilling Fluid Activity On The Hydration Behavior Of Shale Reservoirs In Northwestern Hunan, China, Han Cao, Zheng Zhang, Ting Bao, Pinghe Sun, Tianyi Wang, Qiang Gao

Michigan Tech Publications

The interaction between drilling fluid and shale has a significant impact on wellbore stability during shale oil and gas drilling operations. This paper investigates the effects of the drilling fluid activity on the surface and osmotic hydration characteristics of shale. Experiments were conducted to measure the influence of drilling fluid activity on surface wettability by monitoring the evolution of fluid-shale contact angles. The relationship between drilling fluid activity and shale swelling ratio was determined to investigate the osmotic hydration behavior. The results indicate that, with increasing drilling fluid activity, the fluid–shale contact angles gradually increase—the higher the activity, the faster …


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 …


Cyclotomic Trace Codes, Dean Crnkovic, Andrea Svob, Vladimir Tonchev Aug 2019

Cyclotomic Trace Codes, Dean Crnkovic, Andrea Svob, Vladimir Tonchev

Michigan Tech Publications

A generalization of Ding’s construction is proposed that employs as a defining set the collection of the sth powers (s ≥ 2) of all nonzero elements in GF(pm), where p ≥ 2 is prime. Some of the resulting codes are optimal or near-optimal and include projective codes over GF(4) that give rise to optimal or near optimal quantum codes. In addition, the codes yield interesting combinatorial structures, such as strongly regular graphs and block designs.


Spontaneous Selective Deposition Of Iron Oxide Nanoparticles On Graphite As Model Catalysts, Chathura De Alwis, Timothy Leftwich, Pinaki Mukherjee, Alex Denofre, Kahryn Perrine Aug 2019

Spontaneous Selective Deposition Of Iron Oxide Nanoparticles On Graphite As Model Catalysts, Chathura De Alwis, Timothy Leftwich, Pinaki Mukherjee, Alex Denofre, Kahryn Perrine

Michigan Tech Publications

Iron oxide nanomaterials participate in redox processes that give them ideal properties for their use as earth-abundant catalysts. Fabricating nanocatalysts for such applications requires detailed knowledge of the deposition and growth. We report the spontaneous deposition of iron oxide nanoparticles on HOPG in defect areas and on step edges from a metal precursor solution. To study the nucleation and growth of iron oxide nanoparticles, tailored defects were created on the surface of HOPG using various ion sources that serve as the target sites for iron oxide nucleation. After solution deposition and annealing, the iron oxide nanoparticles were found to nucleate …


Experimental Nitrogen Addition Alters Structure And Function Of A Boreal Bog: Critical Load And Thresholds Revealed, R. Kelman Wieder, Dale H. Vitt, Melanie A. Vile, Jeremy A. Graham, Jeremy A. Hartsock, Hope Fillingim, Et Al. Aug 2019

Experimental Nitrogen Addition Alters Structure And Function Of A Boreal Bog: Critical Load And Thresholds Revealed, R. Kelman Wieder, Dale H. Vitt, Melanie A. Vile, Jeremy A. Graham, Jeremy A. Hartsock, Hope Fillingim, Et Al.

Michigan Tech Publications

Bogs and fens cover 6% and 21%, respectively, of the 140,329 km2 Oil Sands Administrative Area in northern Alberta. Development of the oil sands has led to increasing atmospheric N deposition, with values as high as 17 kg N.ha-1yr-1; regional background deposition is N.ha-1yr-1. Bogs, being ombrotrophic, may be especially susceptible to increasing N deposition. To examine responses to N deposition, over five years, we experimentally applied N (as NH4NO3) to a bog near Mariana Lake, Alberta, unaffected by oil sands activities, at …


Identifying Genetic Markers For A Range Of Phylogenetic Utility–From Species To Family Level, Bokyung Choi, Michael D. Crisp, Lyn G. Cook, Karen Meusemann, Robert D. Edwards, Alicia Toon, Carsten Kulheim Aug 2019

Identifying Genetic Markers For A Range Of Phylogenetic Utility–From Species To Family Level, Bokyung Choi, Michael D. Crisp, Lyn G. Cook, Karen Meusemann, Robert D. Edwards, Alicia Toon, Carsten Kulheim

Michigan Tech Publications

Resolving the phylogenetic relationships of closely related species using a small set of loci is challenging as sufficient information may not be captured from a limited sample of the genome. Relying on few loci can also be problematic when conflict between gene-trees arises from incomplete lineage sorting and/or ongoing hybridization, problems especially likely in recently diverged lineages. Here, we developed a method using limited genomic resources that allows identification of many low copy candidate loci from across the nuclear and chloroplast genomes, design probes for target capture and sequence the captured loci. To validate our method we present data from …


Stability Analysis On Nonequilibrium Supersonic Boundary Layer Flow With Velocity-Slip Boundary Conditions, Xin He, Chunpei Cai Jul 2019

Stability Analysis On Nonequilibrium Supersonic Boundary Layer Flow With Velocity-Slip Boundary Conditions, Xin He, Chunpei Cai

Michigan Tech Publications

This paper presents our recent work on investigating velocity slip boundary conditions’ effects on supersonic flat plate boundary layer flow stability. The velocity-slip boundary conditions are adopted and the flow properties are obtained by solving boundary layer equations. Stability analysis of two such boundary layer flows is performed by using the Linear stability theory. A global method is first utilized to obtain approximate discrete mode values. A local method is then utilized to refine these mode values. All the modes in these two scenarios have been tracked upstream-wisely towards the leading edge and also downstream-wisely. The mode values for the …


Understanding Cumulative Hazards In A Rustbelt City: Integrating Gis, Archaeology, And Spatial History, Daniel Trepal, Don Lafreniere Jul 2019

Understanding Cumulative Hazards In A Rustbelt City: Integrating Gis, Archaeology, And Spatial History, Daniel Trepal, Don Lafreniere

Michigan Tech Publications

We combine the Historical Spatial Data Infrastructure (HSDI) concept developed within spatial history with elements of archaeological predictive modeling to demonstrate a novel GIS-based landscape model for identifying the persistence of historically-generated industrial hazards in postindustrial cities. This historical big data approach draws on over a century of both historical and modern spatial big data to project the presence of specific persistent historical hazards across a city. This research improves on previous attempts to understand the origins and persistence of historical pollution hazards, and our final model augments traditional archaeological approaches to site prospection and analysis. This study also demonstrates …


Multi-Functional Electrospun Nanofibers From Polymer Blends For Scaffold Tissue Engineering, Samerender Nagam Hanumantharao, Smitha Rao Jul 2019

Multi-Functional Electrospun Nanofibers From Polymer Blends For Scaffold Tissue Engineering, Samerender Nagam Hanumantharao, Smitha Rao

Michigan Tech Publications

Electrospinning and polymer blending have been the focus of research and the industry for their versatility, scalability, and potential applications across many different fields. In tissue engineering, nanofiber scaffolds composed of natural fibers, synthetic fibers, or a mixture of both have been reported. This review reports recent advances in polymer blended scaffolds for tissue engineering and the fabrication of functional scaffolds by electrospinning. A brief theory of electrospinning and the general setup as well as modifications used are presented. Polymer blends, including blends with natural polymers, synthetic polymers, mixture of natural and synthetic polymers, and nanofiller systems, are discussed in …


Arbuscular Mycorrhizal Inoculation Has Similar Benefits To Fertilization For Thuja Occidentalis L. Seedling Nutrition And Growth On Peat Soil Over A Range Of Ph: Implications For Restoration, Guswarni Anwar, Erik A. Lilleskov, Rodney Chimner Jul 2019

Arbuscular Mycorrhizal Inoculation Has Similar Benefits To Fertilization For Thuja Occidentalis L. Seedling Nutrition And Growth On Peat Soil Over A Range Of Ph: Implications For Restoration, Guswarni Anwar, Erik A. Lilleskov, Rodney Chimner

Michigan Tech Publications

Arbuscular mycorrhizal (AM) fungi are hypothesized to assist growth of northern white-cedar in acid peatlands, yet there is little direct evidence that they can provide sufficient resources, especially nitrogen (N), from unfertilized peat soils. Our objective was to determine mycorrhizal efficacy to support cedar growth and nutrient supply as part of a low-impact approach for ecological restoration of cedar in peatlands. We tested the effectiveness of AM inoculation in a greenhouse experiment in factorial combination with fertilization and liming. We also determined AM colonization rate in the different treatment combinations. We found that AM inoculation in the absence of fertilization …


Thermal Conduction Simulation Based On Reconstruction Digital Rocks With Respect To Fractures, Haiyuan Yang, Li Zhang, Ronghe Liu, Xianli Wen, Yongfei Yang, Roohollah Askari, Et. Al. Jul 2019

Thermal Conduction Simulation Based On Reconstruction Digital Rocks With Respect To Fractures, Haiyuan Yang, Li Zhang, Ronghe Liu, Xianli Wen, Yongfei Yang, Roohollah Askari, Et. Al.

Michigan Tech Publications

Effective thermal conductivity (ETC), as a necessary parameter in the thermal properties of rock, is affected by the pore structure and the thermal conduction conditions. To evaluate the effect of fractures and saturated fluids on sandstone’s thermal conductivity, we simulated thermal conduction along three orthogonal (X, Y, and Z) directions under air- and water-saturated conditions on reconstructed digital rocks with different fractures. The results show that the temperature distribution is separated by the fracture. The significant difference between the thermal conductivities of solid and fluid is the primary factor influencing the temperature distribution, and the thermal conduction mainly depends on …


Characterizing Boreal Peatland Plant Composition And Species Diversity With Hyperspectral Remote Sensing, Mara Y. Mcpartland, Michael J. Falkowski, Jason R. Reinhardy, Evan Kane, Randall K Kolka, Merritt R. Turetsky, Et Al. Jul 2019

Characterizing Boreal Peatland Plant Composition And Species Diversity With Hyperspectral Remote Sensing, Mara Y. Mcpartland, Michael J. Falkowski, Jason R. Reinhardy, Evan Kane, Randall K Kolka, Merritt R. Turetsky, Et Al.

Michigan Tech Publications

Peatlands, which account for approximately 15% of land surface across the arctic and boreal regions of the globe, are experiencing a range of ecological impacts as a result of climate change. Factors that include altered hydrology resulting from drought and permafrost thaw, rising temperatures, and elevated levels of atmospheric carbon dioxide have been shown to cause plant community compositional changes. Shifts in plant composition affect the productivity, species diversity, and carbon cycling of peatlands. We used hyperspectral remote sensing to characterize the response of boreal peatland plant composition and species diversity to warming, hydrologic change, and elevated CO2. …


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 the …


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 …


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 …


Evaluation Of Copper-Contaminated Marginal Land For The Cultivation Of Vetiver Grass (Chrysopogon Zizanioides) As A Lignocellulosic Feedstock And Its Impact On Downstream Bioethanol Production, Emily Geiger, Dibyendu Sarkar, Rupali Datta Jul 2019

Evaluation Of Copper-Contaminated Marginal Land For The Cultivation Of Vetiver Grass (Chrysopogon Zizanioides) As A Lignocellulosic Feedstock And Its Impact On Downstream Bioethanol Production, Emily Geiger, Dibyendu Sarkar, Rupali Datta

Michigan Tech Publications

Metal-contaminated soil could be sustainably used for biofuel feedstock production if the harvested biomass is amenable to bioethanol production. A 60-day greenhouse experiment was performed to evaluate (1) the potential of vetiver grass to phytostabilize soil contaminated with copper (Cu), and (2) the impact of Cu exposure on its lignocellulosic composition and downstream bioethanol production. Dilute acid pretreatment, enzymatic hydrolysis, and fermentation parameters were optimized sequentially for vetiver grass using response surface methodology (RSM). Results indicate that the lignocellulosic composition of vetiver grown on Cu-rich soil was favorably altered with a significant decrease in lignin and increase in hemicellulose and …


Coupling Ocean Currents And Waves With Wind Stress Over The Gulf Stream, Qi Shi, Mark A. Bourassa Jun 2019

Coupling Ocean Currents And Waves With Wind Stress Over The Gulf Stream, Qi Shi, Mark A. Bourassa

Michigan Tech Publications

This study provides the first detailed analysis of oceanic and atmospheric responses to the current-stress, wave-stress, and wave-current-stress interactions around the Gulf Stream using a high-resolution three-way coupled regional modeling system. In general, our results highlight the substantial impact of coupling currents and/or waves with wind stress on the air–sea fluxes over the Gulf Stream. The stress and the curl of the stress are crucial to mixed-layer energy budgets and sea surface temperature. In the wave-current-stress coupled experiment, wind stress increased by 15% over the Gulf Stream. Alternating positive and negative bands of changes of Ekman-related vertical velocity appeared in …


Neural Network-Based Diagnostic Tool For Detecting Stator Inter-Turn Faults In Line Start Permanent Magnet Synchronous Motors, Luqman S. Maraaba, Zakariya M. Al-Hamouz, Abdulaziz S. Milhem, M. A. Abido Jun 2019

Neural Network-Based Diagnostic Tool For Detecting Stator Inter-Turn Faults In Line Start Permanent Magnet Synchronous Motors, Luqman S. Maraaba, Zakariya M. Al-Hamouz, Abdulaziz S. Milhem, M. A. Abido

Michigan Tech Publications

Three-phase line-start permanent magnet synchronous motors are considered among the most promising types of motors in industrial applications. However, these motors experience several faults, which may cause significant financial losses. This paper proposed a feed-forward neural network-based diagnostic tool for accurate and fast detection of the location and severity of stator inter-turn faults. The input to the neural network is a group of representative statistical and frequency-based features extracted from the steady-state three-phase stator current signals. The current signals with different numbers of shorted turns and loading conditions are captured using the developed finite element JMAG ™ model for interior …


Perspectives On Micrornas And Phased Small Interfering Rnas In Maize (Zea Mays L.): Functions And Big Impact On Agronomic Traits Enhancement, Zhanhui Zhang, Sachin Teotia, Jihua Tang, Guiliang Tang Jun 2019

Perspectives On Micrornas And Phased Small Interfering Rnas In Maize (Zea Mays L.): Functions And Big Impact On Agronomic Traits Enhancement, Zhanhui Zhang, Sachin Teotia, Jihua Tang, Guiliang Tang

Department of Biological Sciences Publications

Small RNA (sRNA) population in plants comprises of primarily micro RNAs (miRNAs) and small interfering RNAs (siRNAs). MiRNAs play important roles in plant growth and development. The miRNA-derived secondary siRNAs are usually known as phased siRNAs, including phasiRNAs and tasiRNAs. The miRNA and phased siRNA biogenesis mechanisms are highly conserved in plants. However, their functional conservation and diversification may differ in maize. In the past two decades, lots of miRNAs and phased siRNAs have been functionally identified for curbing important maize agronomic traits, such as those related to developmental timing, plant architecture, sex determination, reproductive development, leaf morphogenesis, root development …