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Articles 1 - 30 of 2604

Full-Text Articles in Physical Sciences and Mathematics

Steady-State Method To Measure The In-Plane Thermal Conductivity Of Thin Sheet Materials, Evgeny Pakhomenko, Andrew James Wildridge, Abraham Mathew Koshy, Souvik Das, Andreas Jung Aug 2018

Steady-State Method To Measure The In-Plane Thermal Conductivity Of Thin Sheet Materials, Evgeny Pakhomenko, Andrew James Wildridge, Abraham Mathew Koshy, Souvik Das, Andreas Jung

The Summer Undergraduate Research Fellowship (SURF) Symposium

A new generation of silicon pixel detectors is required to cope with the unprecedented luminosities at the high-luminosity phase of the Large Hadron Collider (HL-LHC) in 2025. The HL-LHC provides a high radiation, high interaction rate environment for the innermost detector region of the CMS detector. This can lead to an uncontrolled increase in temperature of the detector that can destroy the silicon pixels. Moreover, too high operating temperature can add noise to the data obtained from the detector and can slow the read out cheap down. Therefore, the Phase II upgrade to the Compact Muon Solenoid (CMS) experiment requires ...


Majorana Spin-Flip Transition In The Alpha Magnetic Trap, Miguel Alarcon, Colin Riggert, Francis Robicheaux Aug 2018

Majorana Spin-Flip Transition In The Alpha Magnetic Trap, Miguel Alarcon, Colin Riggert, Francis Robicheaux

The Summer Undergraduate Research Fellowship (SURF) Symposium

The main purpose of the ALPHA collaboration is to trap antihydrogen atoms so that the Charge Conjugation-Parity Transformation-Time Reversal (CPT) symmetry can be tested. The trapping mechanism consists on an octupole magnet that traps the atoms near the magnetic field minima. Once trapped, due to the Majorana spin-flip effect, atoms can escape by changing the orientation of its spin. The magnetic field generated by the octupole magnet present in the trap has multiple zeroes of different orders. These zeroes could affect the probability of a spin flip, and therefore alter the number of escaped atoms. The main problem tackled by ...


Incorporating Collisions And Resistance Into The Transition From Field Emission To The Space Charge Regime, Samuel D. Dynako, Adam M. Darr, Allen L. Garner Aug 2018

Incorporating Collisions And Resistance Into The Transition From Field Emission To The Space Charge Regime, Samuel D. Dynako, Adam M. Darr, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

Advancements in microelectromechanical systems (MEMS) and microplasmas, particularly with respect to applications in combustion and biotechnology, motivate studies into microscale gas breakdown to enable safe system design and implementation. Breakdown at microscale deviates from that predicted by Paschen’s law due to field emission—the stripping of electrons from the cathode in the presence of strong surface field—and follows the Fowler-Nordheim (FN) law. As injected current increases at this length scale, electrons accumulate in the gap and FN electron emission becomes space charge limited, leading to the Child-Langmuir (CL) law at vacuum and the Mott-Gurney (MG) law at high ...


Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li Aug 2018

Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heterogeneous catalysts are used widely by chemical and energy industries because they show high reactivity but often suffer from lack of selectivity. On the other hand, ligands are commonly used in homogeneous catalysts to control the reactivity and selectivity; however, the effects of the ligands on the steric and electronic properties of heterogeneous catalysts are less understood. We examine the effects of four different ligands: 1-adamantanethiol, 1-adamantylamine, 1-dodecanethiol, and 1-dodecylamine, for the commercial hydrogenation catalyst palladium on carbon. Hydrogenation reactions are used as a screening tool to see the behavior that the different catalysts exhibit in the presence of unsaturated ...


Estimating Watershed Residence Times In Artificially-Drained Landscapes And Relation To Nutrient Concentrations, Emma Beck, Lisa Welp, Alexandra L. Meyer Aug 2018

Estimating Watershed Residence Times In Artificially-Drained Landscapes And Relation To Nutrient Concentrations, Emma Beck, Lisa Welp, Alexandra L. Meyer

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nutrient runoff from agricultural lands feeds harmful algae blooms that create a variety of problems in freshwater ecosystems. In order to reduce the effects of this nutrient runoff, Best Management Practices (BMPs) are being put in place in agricultural lands. Most of these BMPs focus on slowing down the flow of water through the watershed to give nutrient concentrations time to deplete before the water flows to the stream or river. However, the effectiveness of these BMPs are highly unknown and the process of monitoring nutrient runoff is often complex and costly. The data in this study consists of 7 ...


Investigating Dataset Distinctiveness, Andrew Ulmer, Kent W. Gauen, Yung-Hsiang Lu, Zohar R. Kapach, Daniel P. Merrick Aug 2018

Investigating Dataset Distinctiveness, Andrew Ulmer, Kent W. Gauen, Yung-Hsiang Lu, Zohar R. Kapach, Daniel P. Merrick

The Summer Undergraduate Research Fellowship (SURF) Symposium

Just as a human might struggle to interpret another human’s handwriting, a computer vision program might fail when asked to perform one task in two different domains. To be more specific, visualize a self-driving car as a human driver who had only ever driven on clear, sunny days, during daylight hours. This driver – the self-driving car – would inevitably face a significant challenge when asked to drive when it is violently raining or foggy during the night, putting the safety of its passengers in danger. An extensive understanding of the data we use to teach computer vision models – such as ...


Mass Spectrometry Image Creator (Msic): Ion Mobility / Mass Spectrometry Imaging Workflow In Python, Stephen Creger, Julia Laskin, Daniela Mesa Sanchez Aug 2018

Mass Spectrometry Image Creator (Msic): Ion Mobility / Mass Spectrometry Imaging Workflow In Python, Stephen Creger, Julia Laskin, Daniela Mesa Sanchez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Mass spectrometry (MS) is a powerful characterization technique that enables identification of compounds in complex mixtures. Acquiring mass spectra in a spatially-resolved manner (i.e. over a grid), allows the data to be used to generate images that show the spatial distribution and relative intensities of every compound in a sample. These images can be used to monitor and identify biomarkers, explore the metabolism of compounds within tissues, and much more. However, the limitations of mass spectrometry can result in ambiguous compound identifications. Another characterization tool, ion mobility spectrometry (IM) can be integrated into existing MS routines to address this ...


Remote Sensing Using I-Band And S-Band Signals Of Opportunity, Kadir Efecik, Benjamin R. Nold, James L. Garrison Aug 2018

Remote Sensing Using I-Band And S-Band Signals Of Opportunity, Kadir Efecik, Benjamin R. Nold, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Measurement of soil moisture, especially the root zone soil moisture, is important in agriculture, meteorology, and hydrology. Root zone soil moisture is concerned with the first meter down the soil. Active and passive remote sensing methods used today utilizing L-band(1-2GHz) are physically limited to a sensing depth of about 5 cm or less. To remotely sense the soil moisture in the deeper parts of the soil, the frequency should be lowered. Lower frequencies cannot be used in active spaceborne instruments because of their need for larger antennas, radio frequency interference (RFI), and frequency spectrum allocations. Ground-based passive remote sensing ...


Deep Machine Learning For Mechanical Performance And Failure Prediction, Elijah Reber, Nickolas D. Winovich, Guang Lin Aug 2018

Deep Machine Learning For Mechanical Performance And Failure Prediction, Elijah Reber, Nickolas D. Winovich, Guang Lin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Deep learning has provided opportunities for advancement in many fields. One such opportunity is being able to accurately predict real world events. Ensuring proper motor function and being able to predict energy output is a valuable asset for owners of wind turbines. In this paper, we look at how effective a deep neural network is at predicting the failure or energy output of a wind turbine. A data set was obtained that contained sensor data from 17 wind turbines over 13 months, measuring numerous variables, such as spindle speed and blade position and whether or not the wind turbine experienced ...


Stability Of The Interface Between Two Immiscible Liquids During Injection Into A Tapered Hele-Shaw Cell, Zihao Lin, Ivan C. Christov, Daihui Lu Aug 2018

Stability Of The Interface Between Two Immiscible Liquids During Injection Into A Tapered Hele-Shaw Cell, Zihao Lin, Ivan C. Christov, Daihui Lu

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the early twentieth century, petroleum and mining engineers noticed that water does not displace oil uniformly. This phenomenon, when water penetrates through oil, is now known as viscous fingering. This discovery and the following extensive research have contributed to enhancing oil recovery. In this paper, we describe a numerical study conducted on the stability of the interface between two immiscible liquids in converging and diverging Hele-Shaw cells with varying gradients. Hele-Shaw cells are narrow flow geometries that mimic the properties of a porous medium with fixed permeability. By using computational tools built on the OpenFOAM platform, the multiphase flow ...


Exploring Confidentiality Issues In Hyperledger Fabric Business Applications, Shivam Bajpayi, Pedro Moreno-Sanchez, Donghang Lu, Sihao Yin Aug 2018

Exploring Confidentiality Issues In Hyperledger Fabric Business Applications, Shivam Bajpayi, Pedro Moreno-Sanchez, Donghang Lu, Sihao Yin

The Summer Undergraduate Research Fellowship (SURF) Symposium

The rise of Bitcoin and cryptocurrencies over the last decade have made its underlying technology (blockchain) come into the spotlight. Blockchain is a secure ledger of linked records called blocks. These records are cryptographically immutable and any tampering with the block is evident through a change in the cryptographic signature of the block. Among the blockchains deployed in practice today, Hyperledger Fabric is a platform that allows businesses to make use of blockchains in their applications. However, confidentiality issues arise with respects to the blocks in this blockchain network due to the fact that blocks might contain sensitive information accessible ...


Efvs Effects On Pilot Performance, Michael Campbell, Nsikak Udo-Imeh, Steven J. Landry Aug 2018

Efvs Effects On Pilot Performance, Michael Campbell, Nsikak Udo-Imeh, Steven J. Landry

The Summer Undergraduate Research Fellowship (SURF) Symposium

Flight tests have been conducted at Purdue University using a computer-based flying simulator in an attempt to determine and measure the effects of Enhanced Flight Vision Systems (EFVS) on the performance of pilots during landing. Knowledge of these effects could help guide future design and implementation of EFVS in modern commercial aircraft, and further increase pilots’ ability to control the aircraft in low-visibility conditions. The problem that has faced researchers in the past has revolved around the difficulty in interpreting the data which is generated by these tests. The difficulty in making a generalized conclusion based on the large amount ...


Deep Neural Network Architectures For Modulation Classification Using Principal Component Analysis, Sharan Ramjee, Shengtai Ju, Diyu Yang, Aly El Gamal Aug 2018

Deep Neural Network Architectures For Modulation Classification Using Principal Component Analysis, Sharan Ramjee, Shengtai Ju, Diyu Yang, Aly El Gamal

The Summer Undergraduate Research Fellowship (SURF) Symposium

In this work, we investigate the application of Principal Component Analysis to the task of wireless signal modulation recognition using deep neural network architectures. Sampling signals at the Nyquist rate, which is often very high, requires a large amount of energy and space to collect and store the samples. Moreover, the time taken to train neural networks for the task of modulation classification is large due to the large number of samples. These problems can be drastically reduced using Principal Component Analysis, which is a technique that allows us to reduce the dimensionality or number of features of the samples ...


Electronic Effect Of Platinum Alloy Catalysts On Olefin Hydrogenation Kinetics, Colin Reedy, Jeff Miller, Stephen Purdy Aug 2018

Electronic Effect Of Platinum Alloy Catalysts On Olefin Hydrogenation Kinetics, Colin Reedy, Jeff Miller, Stephen Purdy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Dehydrogenation of alkanes is the first step in transforming light hydrocarbons into liquid fuels and chemicals. This process has traditionally used platinum alloys as catalysts. Alloys are used industrially because they have a greater selectivity than monometallic platinum. Alloying platinum with an inactive promoter modifies the crystalline structure of the surface (geometric effect), and the 5d electrons in platinum responsible for chemistry (electronic effect); both have been suggested to be primarily responsible for dehydrogenation selectivity in platinum alloys. Alloy catalysts have been synthesized using early 3d transition metal promoters with the same Pt3M crystal structure. X-Ray Absorption Spectroscopy ...


Sort Vs. Hash Join On Knights Landing Architecture, Victor L. Pan, Felix Lin Aug 2018

Sort Vs. Hash Join On Knights Landing Architecture, Victor L. Pan, Felix Lin

The Summer Undergraduate Research Fellowship (SURF) Symposium

With the increasing amount of information stored, there is a need for efficient database algorithms. One of the most important database operations is “join”. This involves combining columns from two tables and grouping common values in the same row in order to minimize redundant data. The two main algorithms used are hash join and sort merge join. Hash join builds a hash table to allow for faster searching. Sort merge join first sorts the two tables to make it more efficient when comparing values. There has been a lot of debate over which approach is superior. At first, hash join ...


Remote Sensing Of Soil Moisture Using S-Band Signals Of Opportunity: Model Development And Experimental Validation, Marvin Jesse, Benjamin Nold, James L. Garrison Aug 2018

Remote Sensing Of Soil Moisture Using S-Band Signals Of Opportunity: Model Development And Experimental Validation, Marvin Jesse, Benjamin Nold, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Root zone soil moisture (RZSM) is a vital aspect in meteorology, hydrology, and agriculture. There are currently some methods in passive and active remote sensing at L-band, but these methods are limited to a sensing depth of approximately 10 cm. Observing RZSM (water in the top meter of soil) will require lower frequencies, thus presenting significant difficulties for a spaceborne instrument, because of the required antenna size, the presence of radio-frequency interference (RFI), and competition for spectrum allocations (in the case of active radar). Bistatic radar using Signal of Opportunity (SoOp) (e.g. digital satellite transmitters) provides an opportunity for ...


A Divide-And-Conquer Approach To Syntax-Guided Synthesis, Peiyuan Shen, Xiaokang Qiu Aug 2018

A Divide-And-Conquer Approach To Syntax-Guided Synthesis, Peiyuan Shen, Xiaokang Qiu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Program synthesis aims to generate programs automatically from user-provided specifications. One critical research thrust is called Syntax-Guideds Synthesis. In addition to semantic specifications, the user should also provide a syntactic template of the desired program, which helps the synthesizer reduce the search space. The traditional symbolic approaches, such as CounterExample-Guided Inductive Synthesis (CEGIS) framework, does not scale to large search spaces. The goal of this project is to explore a compositional, divide-n-conquer approach that heuristically divides the synthesis task into subtasks and solves them separately. The idea is to decompose the function to be synthesized by creating a set of ...


Expected Length Of The Longest Chain In Linear Hashing, Pongthip Srivarangkul, Hemanta K. Maji Aug 2018

Expected Length Of The Longest Chain In Linear Hashing, Pongthip Srivarangkul, Hemanta K. Maji

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hash table with chaining is a data structure that chains objects with identical hash values together with an entry or a memory address. It works by calculating a hash value from an input then placing the input in the hash table entry. When we place two inputs in the same entry, they chain together in a linear linked list. We are interested in the expected length of the longest chain in linear hashing and methods to reduce the length because the worst-case look-up time is directly proportional to it.

The linear hash function used to calculate hash value is defined ...


Short-Term Organic Carbon Release And Chlorine Disinfectant Decay For Cross-Linked Polyethylene (Pex) Plumbing Pipes, Miriam Tariq, Christian J. Ley, Maryam Salehi, Andrew J. Whelton Aug 2018

Short-Term Organic Carbon Release And Chlorine Disinfectant Decay For Cross-Linked Polyethylene (Pex) Plumbing Pipes, Miriam Tariq, Christian J. Ley, Maryam Salehi, Andrew J. Whelton

The Summer Undergraduate Research Fellowship (SURF) Symposium

The use of cross-linked polyethylene (PEX) plumbing pipes has grown in popularity for residential applications. However, PEX pipes can leach organic materials into water that can enable biofilm growth, cause off-tastes and -odors, and may react with disinfectants to form disinfection by-products (DBP). Varied manufacturing processes that are applied to create PEX pipes add to the complexity of understanding organic materials released. In this study, organic carbon release from three PEX pipe brands was monitored for up to five days using a series of stagnation periods. Seven stagnation periods of 1, 2, 4, 8, 24, 72, and 120 hours were ...


Predict The Failure Of Hydraulic Pumps By Different Machine Learning Algorithms, Yifei Zhou, Monika Ivantysynova, Nathan Keller Aug 2018

Predict The Failure Of Hydraulic Pumps By Different Machine Learning Algorithms, Yifei Zhou, Monika Ivantysynova, Nathan Keller

The Summer Undergraduate Research Fellowship (SURF) Symposium

Pump failure is a general concerned problem in the hydraulic field. Once happening, it will cause a huge property loss and even the life loss. The common methods to prevent the occurrence of pump failure is by preventative maintenance and breakdown maintenance, however, both of them have significant drawbacks. This research focuses on the axial piston pump and provides a new solution by the prognostic of pump failure using the classification of machine learning. Different kinds of sensors (temperature, acceleration and etc.) were installed into a good condition pump and three different kinds of damaged pumps to measure 10 of ...


Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei Aug 2018

Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential ...


Tool For Correlating Ebsd And Afm Data Arrays, Andrew Krawec, Matthew Michie, John Blendell Aug 2018

Tool For Correlating Ebsd And Afm Data Arrays, Andrew Krawec, Matthew Michie, John Blendell

The Summer Undergraduate Research Fellowship (SURF) Symposium

Ceramic and semiconductor research is limited in its ability to create holistic representations of data in concise, easily-accessible file formats or visual data representations. These materials are used in everyday electronics, and optimizing their electrical and physical properties is important for developing more advanced computational technologies. There is a desire to understand how changing the composition of the ceramic alters the shape and structure of the grown crystals. However, few accessible tools exist to generate a dataset with the proper organization to understand correlations between grain orientation and crystallographic orientation. This paper outlines an approach to analyzing the crystal structure ...


International Energy Geopolitics, Bert Chapman Jun 2018

International Energy Geopolitics, Bert Chapman

Libraries Faculty and Staff Presentations

Overview of international energy geopolitical trends. Emphasizes the importance of the Persian Gulf, South China Sea, East China Sea, Russia, and the Arctic to U.S. and international economic and strategic developments. Stresses the continuing importance of fossil fuels in domestic and international energy consumption, the variety of energy sources being used by various global regions, the potential for military conflict over access to natural resources, and how emerging energy leaders will determine global energy, environmental, and international security developments.


Brightness Perception Involves Local Adaptation Opposed By Lateral Interaction, Qasim Zaidi, Romain Bachy, Jose-Manuel Alonso May 2018

Brightness Perception Involves Local Adaptation Opposed By Lateral Interaction, Qasim Zaidi, Romain Bachy, Jose-Manuel Alonso

MODVIS Workshop

No abstract provided.


Understanding Qualitative 3d Shape From Texture And Shading, Benjamin Kunsberg, Steven W. Zucker May 2018

Understanding Qualitative 3d Shape From Texture And Shading, Benjamin Kunsberg, Steven W. Zucker

MODVIS Workshop

No abstract provided.


Measuring Symmetry In Real-World Scenes Using Derivatives Of The Medial Axis Radius Function, Morteza Rezanejad, John D. Wilder, Kaleem Siddiqi, Sven Dickinson, Allan Jepson, Dirk B. Walther May 2018

Measuring Symmetry In Real-World Scenes Using Derivatives Of The Medial Axis Radius Function, Morteza Rezanejad, John D. Wilder, Kaleem Siddiqi, Sven Dickinson, Allan Jepson, Dirk B. Walther

MODVIS Workshop

Symmetry has been shown to be an important principle that guides the grouping of scene information. Previously, we have described a method for measuring the local, ribbon symmetry content of line-drawings of real-world scenes (Rezanejad, et al., MODVIS 2017), and we demonstrated that this information has important behavioral consequences (Wilder, et al., MODIVS 2017). Here, we describe a continuous, local version of the symmetry measure, that allows for both ribbon and taper symmetry to be captured. Our original method looked at the difference in the radius between successive maximal discs along a symmetric axis. The number of radii differences in ...


Consistent Saliency Benchmarking: How One Model Can Win On All Metrics, Matthias Kümmerer, Thomas S.A. Wallis, Matthias Bethge May 2018

Consistent Saliency Benchmarking: How One Model Can Win On All Metrics, Matthias Kümmerer, Thomas S.A. Wallis, Matthias Bethge

MODVIS Workshop

No abstract provided.


Extreme Precipitation Events, Impacts, Trends And Projections For Indiana, Sam Lashley Mar 2018

Extreme Precipitation Events, Impacts, Trends And Projections For Indiana, Sam Lashley

Purdue Road School

The National Weather Service is working with core partners to build a Weather Ready Nation for present and future generations by taking advanced action against the devastating impacts of extreme weather events, including extreme precipitation and flooding. One way in which this can be accomplished is by studying trends in historical weather data and applying what we learn to future mitigation efforts. The goal is to gain a better understanding of the magnitude and impacts that future extreme precipitation events may have on local infrastructure.

This presentation will review extreme rainfall and flooding events that have occurred across Indiana along ...


Roadside Integrated Vegetation Management Bmps: Right Tool For The Right Job, Cheryl Daniels, Davey Resource Group, Inc. Mar 2018

Roadside Integrated Vegetation Management Bmps: Right Tool For The Right Job, Cheryl Daniels, Davey Resource Group, Inc.

Purdue Road School

Based on a 3-year ODOT IVM research project, lessons learned and techniques for innovative and adaptive IVM for diverse midwestern landscapes will be presented that can increase Indiana DOTs’ efficiency and cost-effectiveness and simultaneously improve worker safety, foster safe highway use, improve roadside aesthetics, and promote environmental stewardship.


On The Removal Of Motivation And Structural Barriers In The Classroom And Across The Mathematics Curriculum, Benjamin Wiles, Chantal Levesque-Bristol Feb 2018

On The Removal Of Motivation And Structural Barriers In The Classroom And Across The Mathematics Curriculum, Benjamin Wiles, Chantal Levesque-Bristol

IMPACT Presentations

Presentation at the research roundtable discussion at the 2018 Critical Issues in Math Education Workshop, Mathematical Sciences Research Institute, in Berkeley, CA.

Presents data on the ability of active learning methods to impact motivation and promote learning outcomes in mathematics courses.