Digital Commons Network^™

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 …

On The Hamilton-Waterloo Problem: The Case Of Two Cycles Sizes Of Different Parity, Melissa S. Keranen, Adrian Pastine

Michigan Tech Publications

The Hamilton-Waterloo problem asks for a decomposition of the complete graph of order v into r copies of a 2-factor F1 and s copies of a 2-factor F2 such that r+s = v−1 2 . If F1 consists of m-cycles and F2 consists of n cycles, we say that a solution to (m, n)- HWP(v; r, s) exists. The goal is to find a decomposition for every possible pair (r, s). In this paper, we show that for odd x and y, there is a solution to (2kx, y)-HWP(vm; r, s) if gcd(x, y) ≥ 3, m ≥ 3, and …

I Spy With My Little Eye … A Knee About To Go 'Pop'? Can Coaches And Sports Medicine Professionals Predict Who Is At Greater Risk Of Acl Rupture?, Anne Inger Mørtvedt, Tron Krosshaug, Roald Bahr, Erich Petushek

Michigan Tech Publications

BACKGROUND: The vertical drop jump (VDJ) test is widely used for clinical assessment of ACL injury risk, but it is not clear whether such assessments are valid.

AIM: To examine if sports medicine professionals and coaches are able to identify players at risk of sustaining an ACL injury by visually assessing player performance during a VDJ test.

METHODS: 102 video clips of elite female handball and football players performing a baseline VDJ test were randomly extracted from a 738-person prospective cohort study that tracked ACL injuries. Of the sample, 20 of 102 went on to suffer an ACL injury. These …

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, laboratory …

Families Of Major Index Distributions: Closed Forms And Unimodality, William Keith

Michigan Tech Publications

Closed forms for fλ,i(q):=∑τ∈SYT(λ):des(τ)=iqmaj(τ)fλ,i(q):=∑τ∈SYT(λ):des(τ)=iqmaj(τ), the distribution of the major index over standard Young tableaux of given shapes and specified number of descents, are established for a large collection of λλ and ii. Of particular interest is the family that gives a positive answer to a question of Sagan and collaborators. All formulas established in the paper are unimodal, most by a result of Kirillov and Reshetikhin. Many can be identified as specializations of Schur functions via the Jacobi-Trudi identities. If the number of arguments is sufficiently large, it is shown that any finite principal specialization of any Schur function sλ(1,q,q2,…,qn−1)sλ(1,q,q2,…,qn−1) …

Antibacterial Properties Of Mussel-Inspired Polydopamine Coatings Prepared By A Simple Two-Step Shaking-Assisted Method, Pegah Kord Fooroshani, Elizabeth Polega, Kevin Thomson, Mohammad Saleh Akram Bhuiyan, Rattapol Pinnaratip, Mikhail Trought, Chito E. Kendrick, Yuesheng Gao, Kahryn Perrine, Lei Pan, Bruce P. Lee

Michigan Tech Publications

A simple two-step, shaking-assisted polydopamine (PDA) coating technique was used to impart polypropylene (PP) mesh with antimicrobial properties. In this modified method, a relatively large concentration of dopamine (20 mg ml⁻¹) was first used to create a stable PDA primer layer, while the second step utilized a significantly lower concentration of dopamine (2 mg ml⁻¹) to promote the formation and deposition of large aggregates of PDA nanoparticles. Gentle shaking (70 rpm) was employed to increase the deposition of PDA nanoparticle aggregates and the formation of a thicker PDA coating with nano-scaled surface roughness (RMS = 110 …

Regional Scale Dryland Vegetation Classification With An Integrated Lidar-Hyperspectral Approach, Hamid Dashti, Andrew Poley, Nancy Glenn, Nayani Ilangakoon, Lucas Spaete, Dar Roberts, Et. Al.

Michigan Tech Publications

The sparse canopy cover and large contribution of bright background soil, along with the heterogeneous vegetation types in close proximity, are common challenges for mapping dryland vegetation with remote sensing. Consequently, the results of a single classification algorithm or one type of sensor to characterize dryland vegetation typically show low accuracy and lack robustness. In our study, we improved classification accuracy in a semi-arid ecosystem based on the use of vegetation optical (hyperspectral) and structural (lidar) information combined with the environmental characteristics of the landscape. To accomplish this goal, we used both spectral angle mapper (SAM) and multiple endmember spectral …

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 …

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 …

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

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(p^m), 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

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.

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 …

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.

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

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 …

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 …

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.

Evaluating Visible Derivative Spectroscopy By Varimax-Rotated, Principal Component Analysis Of Aerial Hyperspectral Images From The Western Basin Of Lake Erie, Joseph D. Ortiz, Dulci M. Avouris, Stephan J. Schiller, Jeffrey C. Luvall, John D. Lekki, Roger P. Tokars, Robert C. Anderson, Robert Shuchman, Michael Sayers, Richard Becker

Michigan Tech Publications

The Kent State University (KSU) spectral decomposition method provides information about the spectral signals present in multispectral and hyperspectral images. Pre-processing steps that enhance signal to noise ratio (SNR) by 7.37–19.04 times, enables extraction of the environmental signals captured by the National Aeronautics and Space Administration (NASA) Glenn Research Center's, second generation, Hyperspectral imager (HSI2) into multiple, independent components. We have accomplished this by pre-processing of Level 1 HSI2 data to remove stripes from the scene, followed by a combination of spectral and spatial smoothing to further increase the SNR and remove non-Lambertian features, such as waves. On average, …

Block-Avoiding Sequencings Of Points In Steiner Triple Systems, Donald L. Kreher, Douglas R. Stnson

Michigan Tech Publications

Given an STS(v), we ask if there is a permutation of the points of the design such that no L consecutive points in this permutation contain a block of the design. Such a permutation is called an L-good sequencing. We prove that 3-good sequencings exist for any STS(v) with v>3and 4-good sequencings exist for any STS(v) with v>71. Similar results also hold for partial STS(v). Finally, we determine the existence or nonexistence of 4-good sequencings for all the nonisomorphic STS(v) with v=7,9,13 and 15.

Determining Remote Sensing Spatial Resolution Requirements For The Monitoring Of Harmful Algal Blooms In The Great Lakes, John Lekki, Eric Deutsch, Michael Sayers, Karl Bosse, Robert Anderson, Roger Tokars, Reid W. Sawtell

Michigan Tech Publications

Harmful algal blooms (HABs) have become a major health and environmental concern in the Great Lakes. In 2014, severe HABs prompted the State of Ohio to request NASA Glenn Research Center (GRC) to assist with monitoring algal blooms in Lake Erie. The most notable species of HAB is Microcystis aeruginosa, a hepatotoxin producing cyanobacteria that is responsible for liver complications for humans and other fauna that come in contact with these blooms. NASA GRC conducts semiweekly flights in order to gather up-to-date imagery regarding the blooms' spatial extents and concentrations. Airborne hyperspectral imagery is collected using two hyperspectral imagers, HSI-2 …

Electrophilic Oligodeoxynucleotide Synthesis Using Dm-Dmoc For Amino Protection, Shahien Shahsavari, Dhananjani N. A. M. Eriyagama, Bhaskar Halami, Vagarshak Begoyan, Marina Tanasova, Jinsen Chen, Shiyue Fang

Department of Chemistry Publications

Solid-phase synthesis of electrophilic oligodeoxynucleotides (ODNs) was achieved using dimethyl-Dmoc (dM-Dmoc) as amino protecting group. Due to the high steric hindrance of the 2-(propan-2-ylidene)-1,3-dithiane side product from deprotection, the use of excess nucleophilic scavengers such as aniline to prevent Michael addition of the side product to the deprotected ODN during ODN cleavage and deprotection was no longer needed. The improved technology was demonstrated by the synthesis and characterization of five ODNs including three modified ones. The modified ODNs contained the electrophilic groups ethyl ester, α-chloroamide, and thioester. Using the technology, the sensitive groups can be installed at any location within …

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 …

Detecting Zn(Ii) Ions In Live Cells With Near-Infrared Fluorescent Probes., Mingxi Fang, Shuai Xia, Jianheng Bi, Travis P Wigstrom, Loredana Valenzano, Jianbo Wang, Marina Tanasova, Rudy Luck, Haiying Liu

Michigan Tech Publications

Two near-infrared fluorescent probes (A and B) containing hemicyanine structures appended to dipicolylamine (DPA), and a dipicolylamine derivative where one pyridine was substituted with pyrazine, respectively, were synthesized and tested for the identification of Zn(II) ions in live cells. In both probes, an acetyl group is attached to the phenolic oxygen atom of the hemicyanine platform to decrease the probe fluorescence background. Probe A displays sensitive fluorescence responses and binds preferentially to Zn(II) ions over other metal ions such as Cd²⁺ ions with a low detection limit of 0.45 nM. In contrast, the emission spectra of probe B is …

Bathymetric Surveying In Lake Superior: 3d Modeling And Sonar Equipment Comparing, Eugene Levin, Guy Meadows, Roman Shults, Utku Karacelebi, Hasan Salih Kulunk

School of Technology Publications

This paper represents the overview of hydrographic surveying and different types of modern and traditional surveying equipment, and data acquisition using the traditional single beam sonar system and a modern fully autonomous underwater vehicle (AUV) IVER3. During the study, the data sets were collected using the vehicles of the Great Lake Research Center at Michigan Technological University. This paper presents how to process and edit the bathymetric data on SonarWiz5. Lastly, it compares the accuracy of the two different sonar systems in the different missions and creates 3D models to display and understand the elevations changes. Moreover, the 3D models …

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 with …

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 …

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.

Assessing The Likelihood Of Having False Positives Caused By Population Stratification, Renfang Jiang, Jianping Dong

Michigan Tech Publications

Population stratification is always a concern in association analysis. There is a debate on the extent of the problem in less extreme situations (Thomas and Witte [1], Wacholder et al. [2]). Wacholder et al.[3] and Ardlie et al. [4] showed that hidden population structure is not a serious threat to case-control designs. We propose a method of assessing the seriousness of the population stratification before designing association studies. If population stratification is not a serious problem, one may consider using case-control study instead of family-based design to get more power. In a case-control design, we compare chi-square …

Design Of Single-Modal Take-Over Request In Sae Level 2 & 3 Automated Vehicle, Jiwon Lee, Hanna Yun, Jaewon Kim, Sujin Baek, Hyunseo Han, S. Maryam Fakhr Hosseini, Eric Vasey, Okkeun Lee, Myounghoon Jeon, Ji Hyun Yang

Michigan Tech Publications

Recently, cutting-edge technology has led to the development of automated vehicles, but the limitations of the related technology may lead to hazardous situations. This resulted in the remarkable significance of the interaction between automated vehicles and drivers. In particular, the transition between the driver and the automated vehicle in accordance with Level 3 of SAE J3016 is inevitable, and guidelines or standards regarding the takeover should be provided. Therefore, we aim to prepare the safety guidelines for the takeover and to conduct a comparative test. First, guidelines for visual, auditory, and haptic displays in existing vehicles were examined. Second, preliminary …