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Articles 142741 - 142770 of 302638

Full-Text Articles in Physical Sciences and Mathematics

Nanoparticle Plasmonics: Going Practical With Transition Metal Nitrides, U. Guler, V. M. Shalaev, A. Boltasseva Apr 2015

Nanoparticle Plasmonics: Going Practical With Transition Metal Nitrides, U. Guler, V. M. Shalaev, A. Boltasseva

U. Guler

Promising designs and experimental realizations of devices with unusual properties in the field of plasmonics have attracted a great deal of attention over the past few decades. However, the high expectations for realized technology products have not been met so far. The main complication is the absence of robust, high performance, low cost plasmonic materials that can be easily integrated into already established technologies such as microelectronics. This review provides a brief discussion on alternative plasmonic materials for localized surface plasmon applications and focuses on transition metal nitrides, in particular, titanium nitride, which has recently been shown to be a …


Topological Data Analysis Of Biological Aggregation Models, Chad M. Topaz, Lori Ziegelmeier, Tom Halverson Apr 2015

Topological Data Analysis Of Biological Aggregation Models, Chad M. Topaz, Lori Ziegelmeier, Tom Halverson

Chad M. Topaz

We apply tools from topological data analysis to two mathematical models inspired by biological aggregations such as bird flocks, fish schools, and insect swarms. Our data consists of numerical simulation output from the models of Vicsek and D'Orsogna. These models are dynamical systems describing the movement of agents who interact via alignment, attraction, and/or repulsion. Each simulation time frame is a point cloud in position-velocity space. We analyze the topological structure of these point clouds, interpreting the persistent homology by calculating the first few Betti numbers. These Betti numbers count connected components, topological circles, and trapped volumes present in the …


Comprehensive Quantification Of Triacylglycerols In Soybean Seeds By Electrospray Ionization Mass Spectrometry With Multiple Neutral Loss Scans, Maoyin Li, Emily Butka, Xuemin Wang Apr 2015

Comprehensive Quantification Of Triacylglycerols In Soybean Seeds By Electrospray Ionization Mass Spectrometry With Multiple Neutral Loss Scans, Maoyin Li, Emily Butka, Xuemin Wang

Xuemin (Sam) Wang

Soybean seeds are an important source of vegetable oil and biomaterials. The content of individual triacylglycerol species (TAG) in soybean seeds is difficult to quantify in an accurate and rapid way. The present study establishes an approach to quantify TAG species in soybean seeds utilizing an electrospray ionization tandem mass spectrometry with multiple neutral loss scans. Ten neutral loss scans were performed to detect the fatty acyl chains of TAG, including palmitic (P, 16:0), linolenic (Ln, 18:3), linoleic (L, 18:2), oleic (O, 18:1), stearic (S, 18:0), eicosadienoic (20:2), gadoleic (20:1), arachidic (20:0), erucic (22:1), and behenic (22:0). The abundance of …


Org Or Inorg? Atmospheric Carbon Controls That Initiated The Late Paleozoic Ice Age 326mya, Paco Defrancis Apr 2015

Org Or Inorg? Atmospheric Carbon Controls That Initiated The Late Paleozoic Ice Age 326mya, Paco Defrancis

CLAS: Colby Liberal Arts Symposium

The Late Paleozoic Ice Age (LPIA) was a major global icehouse that initiated in the Mississippian (326 million years ago; ma) and lasted through the Early Permian (267ma). An ice sheet nucleated in southern Gondwana near the South Pole, which either paleogeography (positioning of paleocontinents) or atmospheric concentration of the greenhouse gas CO2 controlled. In this paper I accept recent findings that prove atmospheric pCO2 and not paleogeography forced global cooling that resulted in the nucleation of Gondwanan ice sheets that defined the LPIA. There remains no broad consensus of what caused pCO2 lowering in the Mississippian. Organic carbon found …


An Exploration Into Computer Graphics: L-Systems And A Non-Photorealistic Filter, Victoria Edwards Apr 2015

An Exploration Into Computer Graphics: L-Systems And A Non-Photorealistic Filter, Victoria Edwards

CLAS: Colby Liberal Arts Symposium

This past fall I worked on developing a graphics pipeline. I implemented a handful of graphics algorithms that allowed me to render creative scenes. This semester we explored the world of computer graphics by doing an in-depth study of different areas in the field. To do this we read critical SIGGRAPH papers on the subjects. SIGGRAPH is the publication forum for computer graphics and it maps the last forty years of research in the computer graphics world. This semester I have decided to focused on the photorealistic method of creating L-Systems and a non-photo realistic image filter.


Exploring Computer Graphics: Photorealistic And Non-Photorealistic Rendering, Brittany Chin Apr 2015

Exploring Computer Graphics: Photorealistic And Non-Photorealistic Rendering, Brittany Chin

CLAS: Colby Liberal Arts Symposium

Over the course of the year, the Advanced Computer Graphics course has explored a variety of image rendering techniques starting with the basic filling of polygons, and working all the way up to non-photorealistic rendering techniques. I have implemented a variety of these techniques in projects which demonstrate the growth and advancements of graphics over time. The implementations that are featured are an interactive tile game, a curve editor, a ray-tracer, and a non-photorealistic project. The capabilities of computer graphics are seemingly endless, and it is getting easier and easier to model the real world in synthetic systems. Where will …


Graphics, Beatrice Liang Apr 2015

Graphics, Beatrice Liang

CLAS: Colby Liberal Arts Symposium

Here I show images generating using computer graphics methods ranging from green screen images to 3D models


Photorealistic Computer Rendering, William Kearney Apr 2015

Photorealistic Computer Rendering, William Kearney

CLAS: Colby Liberal Arts Symposium

Sample portfolio demonstrating photorealistic and non-photorealistic computer graphic techniques such as ray tracing and edge detection.


3d Model Generation From Flat Images And Other Pretty Pictures, Matthew Levine Apr 2015

3d Model Generation From Flat Images And Other Pretty Pictures, Matthew Levine

CLAS: Colby Liberal Arts Symposium

We present a novel method of generating 3D models from 2D images using neural network techniques. We also show a custom implementation of a global illumination model natively integrated into Python's standard 2D image library (with a fast C backend).


Trees And Non-Photorealistic Images, Christopher Burnham Apr 2015

Trees And Non-Photorealistic Images, Christopher Burnham

CLAS: Colby Liberal Arts Symposium

Showing of a graphics system with some trees and non-photorealistic images.


A Look Into Graphics Engines And Non-Photorealistic Rendering, Margaux Leblanc Apr 2015

A Look Into Graphics Engines And Non-Photorealistic Rendering, Margaux Leblanc

CLAS: Colby Liberal Arts Symposium

Throughout the year I have created a graphics pipeline that can render both photorealistic and non-photorealistic images. It all starts with defining what a pixel is and building from there. For instance, an image is a collection of pixels, a color is just three numbers (red, green, and blue values), a line is coloring certain pixels with such a color based on Bresenham's line algorithm and so on. My graphics engine can draw and shade points, lines, polylines, and polygons according to different algorithms. Using these basic shapes I can create photorealistic images of L-systems and non-photorealistic images of paintbrush …


Computer Graphics Presentation, Itrat Akhter Apr 2015

Computer Graphics Presentation, Itrat Akhter

CLAS: Colby Liberal Arts Symposium

The aim of this poster presentation is to display the works that I did over two semester of computer graphics classes. As such, I will give a brief glimpse of the methods and images involving fractals, bezier curves and surfaces, hierarchical modeling, shading and lighting, particle systems and others.


The Fierce Green Fire: Vol 5 Issue 22, Wofford College Environmental Studies Program Apr 2015

The Fierce Green Fire: Vol 5 Issue 22, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.


Mapping Regional Inundation With Spaceborne L-Band Sar, Bruce Chapman, Kyle Macdonald, Masanobu Shimada, Ake Rosenqvist, Ronny Schroeder, Laura Hess Apr 2015

Mapping Regional Inundation With Spaceborne L-Band Sar, Bruce Chapman, Kyle Macdonald, Masanobu Shimada, Ake Rosenqvist, Ronny Schroeder, Laura Hess

Publications and Research

Shortly after the launch of ALOS PALSAR L-band SAR by the Japan Space Exploration Agency (JAXA), a program to develop an Earth Science Data Record (ESDR) for inundated wetlands was funded by NASA. Using established methodologies, extensive multi-temporal L-band ALOS ScanSAR data acquired bi-monthly by the PALSAR instrument onboard ALOS were used to classify the inundation state for South America for delivery as a component of this Inundated Wetlands ESDR (IW-ESDR) and in collaboration with JAXA’s ALOS Kyoto and Carbon Initiative science programme. We describe these methodologies and the final classification of the inundation state, then compared this with results …


Changes In Heavy Rainstorm Characteristics With Time And Temperature, Barry A. Palynchuk Phd, Yiping Guo Phd Apr 2015

Changes In Heavy Rainstorm Characteristics With Time And Temperature, Barry A. Palynchuk Phd, Yiping Guo Phd

Barry A. Palynchuk PhD

The effects of climate change upon extreme rainfall is evaluated, based upon the identification of individual storms, and the changes in their statistical parameters and distributions. Those changes will be measured based upon historical time spans, and climatic temperature associated with the events. A brief review and comparison with other research is provided.


Changes In Heavy Rainstorm Characteristics With Time And Temperature - Presentation, Barry A. Palynchuk Phd Apr 2015

Changes In Heavy Rainstorm Characteristics With Time And Temperature - Presentation, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

The effects of climate change upon extreme rainfall is evaluated, based upon the identification of individual storms, and the changes in their statistical parameters and distributions. Those changes will be measured based upon historical time spans, and climatic temperature associated with the events. A brief review and comparison with other research provided.


Langmuir Probes In A Microwave Generated Plasma, Wesley Rawlins Apr 2015

Langmuir Probes In A Microwave Generated Plasma, Wesley Rawlins

Physics Capstone Projects

In this work, we considered a microwave generated plasma, in a toroidal device. In this set up, we tend to meet the conditions for several known plasma instabilities. Not all the gas in the chamber was ionized. Using a Langmuir probe we were able to determine the population temperature and the plasma density in the chamber. The existence of a plasma was determined by measuring the strength of reflected microwaves. We varied the fill pressure in the chamber, as well as the strength of an externally imposed magnetic field. From this, we determined that the plasma temperature decreased with an …


Imaging The Brigham City Fault Segment Using Electrical Resistivity Tomography Techniques, Alex Barker Apr 2015

Imaging The Brigham City Fault Segment Using Electrical Resistivity Tomography Techniques, Alex Barker

Physics Capstone Projects

Geologic faults are a result of rock structures that have given away to tectonic compression, extension, or lateral tension. Because of a fault’s propensity to slip and cause earthquakes, they are of major concern to any populated area near by. The Wasatch Fault is a result of extensional stress that runs the entire length of Utah from north the south. It has been analyzed and broken up into several segments. By stratigraphic analysis, scientists have been able to estimate when each of these segments has last experienced a rupture. Out of all the segments that make up the Wasatch Fault, …


Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James Bashkin, Gregory Poon Apr 2015

Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James Bashkin, Gregory Poon

Chemistry & Biochemistry Faculty Works

The ETS family of transcription factors exemplifies current uncertainty in how eukaryotic genetic regulators with overlapping DNA sequence preferences achieve target site specificity. PU.1 and Ets-1 represent archetypes for studying site discrimination by ETS proteins because their DNA-binding domains are the most divergent in sequence, yet they share remarkably superimposable DNA-bound structures. To gain insight into the contrasting thermodynamics and kinetics of DNA recognition by these two proteins, we investigated the structure and dynamics of site discrimination by their DNA-binding domains. Electrophoretic mobilities of complexes formed by the two homologs with circularly permuted binding sites showed significant dynamic differences only …


Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James K. Bashkin, Gregory M. K. Poon Apr 2015

Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James K. Bashkin, Gregory M. K. Poon

James Bashkin

The ETS family of transcription factors exemplifies current uncertainty in how eukaryotic genetic regulators with overlapping DNA sequence preferences achieve target site specificity. PU.1 and Ets-1 represent archetypes for studying site discrimination by ETS proteins because their DNA-binding domains are the most divergent in sequence, yet they share remarkably superimposable DNA-bound structures. To gain insight into the contrasting thermodynamics and kinetics of DNA recognition by these two proteins, we investigated the structure and dynamics of site discrimination by their DNA-binding domains. Electrophoretic mobilities of complexes formed by the two homologs with circularly permuted binding sites showed significant dynamic differences only …


Optical Down-Conversion In Doped Znse:Tb3+ Nanocrystals, Sandip Das, K. C. Mandal Apr 2015

Optical Down-Conversion In Doped Znse:Tb3+ Nanocrystals, Sandip Das, K. C. Mandal

Krishna C. Mandal

No abstract provided.


In Situ Infrared Evidence For The Electrochemical Incorporation Of Hydrogen Into Si And Ge, K. C. Mandal, F. Ozanam, J.-N. Chazalviel Apr 2015

In Situ Infrared Evidence For The Electrochemical Incorporation Of Hydrogen Into Si And Ge, K. C. Mandal, F. Ozanam, J.-N. Chazalviel

Krishna C. Mandal

No abstract provided.


Investigation Of Cdznte Crystal Defects Using Scanning Probe Microscopy, Goutam Koley, J. Liu, K. C. Mandal Apr 2015

Investigation Of Cdznte Crystal Defects Using Scanning Probe Microscopy, Goutam Koley, J. Liu, K. C. Mandal

Krishna C. Mandal

No abstract provided.


A Photometric Study Of The Eclipsing Binary Star Uv Lyncis, Edward J. Michaels Apr 2015

A Photometric Study Of The Eclipsing Binary Star Uv Lyncis, Edward J. Michaels

Bright Ideas Conference

UV Lyncis is a short period, over contact eclipsing binary star. These stars are physically in contact with each other, sharing a common atmosphere. Photometric observations were made on 10 nights in February and March 2014 using the 0.3 meter robotic telescope and a CCD science imager at the Waffelow Creek Observatory. 3051 images were acquired, calibrated and then reduced to record the changing brightness as the two stars orbited and eclipsed each other. Data collected resulted in complete light curves in 5 band passes and several times of minima. A period analysis confirmed previous studies that the orbital period …


A Fixed-Inverse Binary Misclassification Model Under Possible False-Positive Misclassification, Asmerom Tesfamichael, Kent Riggs Apr 2015

A Fixed-Inverse Binary Misclassification Model Under Possible False-Positive Misclassification, Asmerom Tesfamichael, Kent Riggs

Bright Ideas Conference

In this project, we develop a particular statistical model for binary data that allows for the possibility of false-positive misclassification. To account for the misclassification, the model incorporates a two-stage sampling scheme.

• Next, we apply maximum likelihood methods to find estimators of the primary prevalence parameter p as well as the false-positive misclassification rate parameter ϕ. In addition, we derive confidence intervals for p based on inverting Wald, score and likelihood ratio statistics.

• Also, we graphically compare coverage and width properties of the Wald-based, score-based, and likelihood ratio-based confidence intervals for p through a Monte Carlo simulation. The …


Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal, B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal Apr 2015

Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal, B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal

Krishna C. Mandal

No abstract provided.


Characterizations Of Antimony Tri‐Sulfide Chemically Deposited With Silicotungstic Acid, O. Savadogo, K. C. Mandal Apr 2015

Characterizations Of Antimony Tri‐Sulfide Chemically Deposited With Silicotungstic Acid, O. Savadogo, K. C. Mandal

Krishna C. Mandal

No abstract provided.


Erratum: “Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal” [Appl. Phys. Lett.87, 182104 (2005)], B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal Apr 2015

Erratum: “Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal” [Appl. Phys. Lett.87, 182104 (2005)], B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal

Krishna C. Mandal

No abstract provided.


Investigation Of Cdznte Crystal Defects Using Scanning Probe Microscopy, Goutam Koley, J. Liu, K. C. Mandal Apr 2015

Investigation Of Cdznte Crystal Defects Using Scanning Probe Microscopy, Goutam Koley, J. Liu, K. C. Mandal

Krishna C. Mandal

No abstract provided.


Tb3+-Doped K Pb2Br5: Low-Energy Phonon Mid-Infrared Laser Crystal, U. N. Roy, R. H. Hawrami, Y. Cui, S. Morgan, A. Burger, K. C. Mandal, C. C. Noblitt, S. A. Speakman, K. Rademaker, S. A. Payne Apr 2015

Tb3+-Doped K Pb2Br5: Low-Energy Phonon Mid-Infrared Laser Crystal, U. N. Roy, R. H. Hawrami, Y. Cui, S. Morgan, A. Burger, K. C. Mandal, C. C. Noblitt, S. A. Speakman, K. Rademaker, S. A. Payne

Krishna C. Mandal

No abstract provided.