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2013

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Articles 151 - 180 of 8928

Full-Text Articles in Physical Sciences and Mathematics

Digital Outcrop Model And Paleoecology Of The Eight-Foot Rapid Algal Field (Middle Pennsylvanian Lower Ismay Sequence), Paradox Basin, Utah, Colton Lynn Goodrich Dec 2013

Digital Outcrop Model And Paleoecology Of The Eight-Foot Rapid Algal Field (Middle Pennsylvanian Lower Ismay Sequence), Paradox Basin, Utah, Colton Lynn Goodrich

Theses and Dissertations

Although phylloid algal mounds have been studied for 50 year, much remains to be determined concerning the ecology and sedimentology of these Late Paleozoic carbonate buildups. Herein we perform a digital outcrop study of the well-known Middle Pennsylvanian Lower Ismay mound interval in the Paradox Basin because outcropping mounds along the San Juan River are cited as outcrop analogs of reservoir carbonates in the Paradox Basin oil province of Utah and adjacent states. The principal field area is the Eight Foot algal field located at river mile 19.2 on the San Juan River, approximately 14 miles SSW of Bluff, Utah. …


Rigidity And Flexibility Of Protein-Nucleic Acid Complexes, Emily Flynn, Filip Jagodzinski, Sharon Pamela Santana, Ileana Streinu Dec 2013

Rigidity And Flexibility Of Protein-Nucleic Acid Complexes, Emily Flynn, Filip Jagodzinski, Sharon Pamela Santana, Ileana Streinu

Computer Science: Faculty Publications

The study of protein-nucleic acid complexes is relevant for the understanding of many biological processes, including transcription, translation, replication, and recombination. The individual molecules in such complexes must be rigid enough to allow geometric matching of complementary shapes, yet sufficiently flexible to perform their functions. © 2013 IEEE.


Universal Quantum Fluctuations Of A Cavity Mode Driven By A Josephson Junction, A. D. Armour, M. P. Blencowe, E. Brahimi, A. J. Rimberg Dec 2013

Universal Quantum Fluctuations Of A Cavity Mode Driven By A Josephson Junction, A. D. Armour, M. P. Blencowe, E. Brahimi, A. J. Rimberg

Dartmouth Scholarship

We analyze the quantum dynamics of a superconducting cavity coupled to a voltage-biased Josephson junction. The cavity is strongly excited at resonances where the voltage energy lost by a Cooper pair traversing the circuit is a multiple of the cavity photon energy. We find that the resonances are accompanied by substantial squeezing of the quantum fluctuations of the cavity over a broad range of parameters and are able to identify regimes where the fluctuations in the system take on universal values.


Analysis Of Mathematical Models Of The Human Lung, Cooper Racheal Dec 2013

Analysis Of Mathematical Models Of The Human Lung, Cooper Racheal

Theses and Dissertations

The processes of lung ventilation and perfusion, diffusion, and gas transport make up the system of breathing and tissue oxygenation. Here, we present several mathematical formulations of the essential processes that contribute to breathing. These models aid in our understanding and analysis of this complex system and can be used to form treatments for patients on ventilators. With the right analysis and treatment options, patients can be helped and money can be saved. We conclude with the formulation of a mathematical model for the exchange of gasses in the body based on basic reaction kinetics.


Multi-Column Multi-Layer Computational Model Of Neocortex, Beata Strack Dec 2013

Multi-Column Multi-Layer Computational Model Of Neocortex, Beata Strack

Theses and Dissertations

We present a multi-layer multi-column computational model of neocortex that is built based on the activity and connections of known neuronal cell types and includes activity-dependent short term plasticity. This model, a network of spiking neurons, is validated by showing that it exhibits activity close to biology in terms of several characteristics: (1) proper laminar flow of activity; (2) columnar organization with focality of inputs; (3) low-threshold-spiking (LTS) and fast-spiking (FS) neurons function as observed in normal cortical circuits; and (4) different stages of epileptiform activity can be obtained with either increasing the level of inhibitory blockade, or simulation of …


Using Delay-Differential Equations For Modeling Calcium Cycling In Cardiac Myocytes, Ryan Thompson Dec 2013

Using Delay-Differential Equations For Modeling Calcium Cycling In Cardiac Myocytes, Ryan Thompson

Theses

The cycling of calcium at the intracellular level of cardiac cells plays a key role in the excitation-contraction process. The interplay between ionic currents, buffering agents, and calcium release from the sarcoplasmic reticulum (SR) is a complex system that has been shown experimentally to exhibit complex dynamics including period-2 states (alternans) and higher-order rhythms. Many of the calcium cycling activities involve the sensing, binding, or diffusion of calcium between intracellular compartments; these are physical processes that take time and typically are modeled by “relaxation” equations where the steady-state value and time course of a particular variable are specified through an …


Mathematical Model Of Dynamic Protein Interactions Regulating P53 Protein Stability For Tumor Suppression, Hua Wang, Guang Peng Dec 2013

Mathematical Model Of Dynamic Protein Interactions Regulating P53 Protein Stability For Tumor Suppression, Hua Wang, Guang Peng

Mathematical Sciences: Faculty Publications

In the field of cancer biology, numerous genes or proteins form extremely complex regulatory network, which determines cancer cell fate and cancer cell survival. p53 is a major tumor suppressor that is lost in more than 50% of human cancers. It has been well known that a variety of proteins regulate its protein stability, which is essential for its tumor suppressive function. It remains elusive how we could understand and target p53 stabilization process through network analysis. In this paper we discuss the use of random walk and stationary distribution to measure the compound effect of a network of genes …


Designing Optimal Innovation Portfolio, Arcot Desai Narasimhalu Dec 2013

Designing Optimal Innovation Portfolio, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

There have been many approaches towards investing in innovation projects. There has been very little discussion about the need to align such investments with the mission, vision, goals, leadership style, value discipline and risk appetite of an organization. This paper reviews existing approaches to innovation related investments and suggests the setting up of a proper innovation portfolio management process along with three dashboards that will help make innovation related investment decisions in an informed manner. The resulting innovation portfolio will be optimal in its alignment with an organizations mission and vision. We expect this method to be used by all …


Halogenation Effects In Intramolecular Furan Diels-Alder Reactions: Broad Scope Synthetic And Computational Studies, Robert L. Rae, Justyna M. Zurek, Martin J. Paterson, Magnus Bebbington Dec 2013

Halogenation Effects In Intramolecular Furan Diels-Alder Reactions: Broad Scope Synthetic And Computational Studies, Robert L. Rae, Justyna M. Zurek, Martin J. Paterson, Magnus Bebbington

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

For the first time a comprehensive synthetic and computational study of the effect of halogen substitution on both furan and dienophile for the intramolecular Furan Diels-Alder (IMDAF) reaction has been undertaken. Contrary to our initial expectations, halogen substitution on the dienophile was found to have a significant effect, making the reactions slower and less thermodynamically favourable. However, careful choice of the site of furan halogenation could be used to overcome dienophile halogen substitution, leading to highly functionalised cycloadducts. These reactions are thought to be controlled by the interplay of three factors: positive charge stabilisation in the transition state and product, …


The Unexpectedly Bright Comet C/2012 F6 (Lemmon) Unveiled At Near-Infrared Wavelengths, Lucas Paganini, Michael Disanti, Michael Mumma, Geronimo Villanueva, Boncho Bonev, Jacqueline Keane, Erika Gibb, Hermann Boehnhardt, Karen Meech Dec 2013

The Unexpectedly Bright Comet C/2012 F6 (Lemmon) Unveiled At Near-Infrared Wavelengths, Lucas Paganini, Michael Disanti, Michael Mumma, Geronimo Villanueva, Boncho Bonev, Jacqueline Keane, Erika Gibb, Hermann Boehnhardt, Karen Meech

Physics Faculty Works

We acquired near-infrared spectra of the Oort cloud comet C/2012 F6 (Lemmon) at three different heliocentric distances (R h) during the comet's 2013 perihelion passage, providing a comprehensive measure of the outgassing behavior of parent volatiles and cosmogonic indicators. Our observations were performed pre-perihelion at R h = 1.2 AU with CRIRES (on 2013 February 2 and 4), and post-perihelion at R h = 0.75 AU with CSHELL (on March 31 and April 1) and R h = 1.74 AU with NIRSPEC (on June 20). We detected 10 volatile species (H2O, OH* prompt emission, C2H6, CH3OH, H2CO, HCN, CO, CH4, …


The Progenitors Of The Compact Early-Type Galaxies At High Redshift, Christina C. Williams, Mauro Giavalisco, Paolo Cassata, Elena Tundo, Tommy Wiklind, Yicheng Guo, Bomee Lee, Guillermo Barro, Stijn Wuyts, Eric F. Bell, Christopher J. Conselice, Avishai Dekel, Sandra M. Faber, Henry C. Ferguson, Norman A. Grogin, Nimish Hathi, Kuang-Han Huang, Dalibor D. Kocevski, Anton M. Koekemoer, David C. Koo, Swara Ravindranath, Sarah Salimbeni Dec 2013

The Progenitors Of The Compact Early-Type Galaxies At High Redshift, Christina C. Williams, Mauro Giavalisco, Paolo Cassata, Elena Tundo, Tommy Wiklind, Yicheng Guo, Bomee Lee, Guillermo Barro, Stijn Wuyts, Eric F. Bell, Christopher J. Conselice, Avishai Dekel, Sandra M. Faber, Henry C. Ferguson, Norman A. Grogin, Nimish Hathi, Kuang-Han Huang, Dalibor D. Kocevski, Anton M. Koekemoer, David C. Koo, Swara Ravindranath, Sarah Salimbeni

Physics and Astronomy Faculty Publications

We use GOODS and CANDELS images to identify progenitors of massive (M > 1010 M ☉) compact early-type galaxies (ETGs) at z ~ 1.6. Because merging and accretion increase the size of the stellar component of galaxies, if the progenitors are among known star-forming galaxies, these must be compact themselves. We select candidate progenitors among compact Lyman-break galaxies at z ~ 3 on the basis of their mass, star-formation rate (SFR), and central stellar density, and we find that these account for a large fraction of, and possibly all, compact ETGs at z ~ 1.6. We find that …


Using Intelligent Prefetching To Reduce The Energy Consumption Of A Large-Scale Storage System, Brian Romoser, Ziliang Zong, Ribel Fares, Joal Wood, Rong Ge Dec 2013

Using Intelligent Prefetching To Reduce The Energy Consumption Of A Large-Scale Storage System, Brian Romoser, Ziliang Zong, Ribel Fares, Joal Wood, Rong Ge

Mathematics, Statistics and Computer Science Faculty Research and Publications

Many high performance large-scale storage systems will experience significant workload increases as their user base and content availability grow over time. The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) center hosts one such system that has recently undergone a period of rapid growth as its user population grew nearly 400% in just about three years. When administrators of these massive storage systems face the challenge of meeting the demands of an ever increasing number of requests, the easiest solution is to integrate more advanced hardware to existing systems. However, additional investment in hardware may significantly increase the …


Environmental Analysis Of Goes-R Proving Ground Convection Initiation Forecasting Algorithms, Jason M. Apke Dec 2013

Environmental Analysis Of Goes-R Proving Ground Convection Initiation Forecasting Algorithms, Jason M. Apke

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The enhanced temporal and spatial resolution of the GOES-R series will allow for the use of cloud top cooling based convection initiation (CI) forecasting algorithms. Two such algorithms have been created on the current generation of GOES satellites: theUniversityofWisconsincloud top cooling algorithm (UWCTC) and the University of Alabama-Huntsville’s satellite convection analysis and tracking algorithm (SATCAST). Preliminary analysis of algorithm products has led to speculation over pre-convective environmental effects on algorithm performance, which this study aims to examine. CI indications are used with objective segmentation tools to identify and cluster radar objects over theGreat Plainsbased on reflectivity quantitative and spatial thresholds. …


A Decentralized Fault Accommodation Scheme For Nonlinear Interconnected Systems, H. Ferdowsi, S. Jagannathan Dec 2013

A Decentralized Fault Accommodation Scheme For Nonlinear Interconnected Systems, H. Ferdowsi, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel decentralized detection and accommodation (FDA) methodology is proposed for interconnected nonlinear continuous-time systems by using local subsystem states alone in contrast with traditional distributed FDA schemes where the entire measured or the estimated state vector is needed. First, the detection scheme is revisited where a network of local fault detectors (LFD) is proposed. A fault is detected by generating a residual from the measured and estimated state vectors locally and the fault dynamics are estimated by using an online approximator upon detection. Subsequently, a fault accommodation scheme is initiated in the subsystem by using a …


A Neural Network Based Outlier Identification And Removal Scheme, H. Ferdowsi, S. Jagannathan, M. Zawodniok Dec 2013

A Neural Network Based Outlier Identification And Removal Scheme, H. Ferdowsi, S. Jagannathan, M. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Identifying and removing the outliers is important in order to make the data more trustworthy and improve the reliability of fault detection, since outliers in the measured data can cause false alarms. An online outlier identification and removal (OIR) scheme, suitable for nonlinear dynamic systems, is proposed in this paper. A neural network (NN) is utilized to estimate the actual outlier-free system states using only the measured system states which involve outliers. Outlier identification is performed online by finding the difference between measured and estimated states and comparing it with its median and standard deviation over a dynamic time window. …


Optically-Pumped Spin-Exchange Polarized Electron Source, Munir Pirbhai Dec 2013

Optically-Pumped Spin-Exchange Polarized Electron Source, Munir Pirbhai

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Polarized electron beams are an indispensable probe of spin-dependent phenomena in fields of atomic and molecular physics, magnetism and biophysics. While their uses have become widespread, the standard source based on negative electron affinity gallium arsenide (GaAs) remains technically complicated. This has hindered progress on many experiments involving spin-polarized electrons, especially those using target gas loads, which tend to adversely affect the performance of GaAs sources. A robust system based on an alternative way to make polarized electron beams has been devised in this study, which builds on previous work done in our lab. It involves spin-exchange collisions between free, …


When All Seems Lost: A Discussion On The Implications Of Using Medicine For Scientific Advances, Rebecca Monterusso Dec 2013

When All Seems Lost: A Discussion On The Implications Of Using Medicine For Scientific Advances, Rebecca Monterusso

Honors Theses

When All is Lost is a creative non-fiction piece following the lives of two fictional characters living during World War" and the Holocaust. It is meant to discuss the moral quandary when human experimentation is used for the purpose of scientific advancement. The two main characters lives' are depicted in a series of modified scenes that describe what happens to them throughout the war. Leo Weinstock is a Jewish man who is chosen for the high-altitude experiments at Dachau after he is imprisoned during Kristallnacht. Erich, on the other hand, is a young, successful Luftwaffe pilot defending his country. Both …


Stability And Entanglement In An Optomechanical System, Matthew Schumacher Dec 2013

Stability And Entanglement In An Optomechanical System, Matthew Schumacher

Theses

Optomechanical systems are currently of great interest as they lie at the boundary between quantum and classical mechanics, promising fundamental insights as well as new technologies. The practical operation of an optomechanical system requires that it satisfy the criteria of mechanical stability. Further, for quantum applications, it is important to characterize the degree of nonclassical correlation present between the mechanical and optical subsystems. In this study, we analyze the stability and entanglement in an optomechanical system where couplings linear as well as quadratic in the mechanical displacement are present simultaneously. Such systems can be realized experimentally. Our analysis of the …


Shifting Environmental Controls On Ch4 Fluxes In A Sub-Boreal Peatland, Thomas G. Pypker, P. A. Moore, John A. Hribljan, Rodney Chimner Dec 2013

Shifting Environmental Controls On Ch4 Fluxes In A Sub-Boreal Peatland, Thomas G. Pypker, P. A. Moore, John A. Hribljan, Rodney Chimner

Michigan Tech Publications, Part 1

We monitored CO2 and CH4 fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH4 from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH4 over the measurement period. Net daily CH4 fluxes increased from 70 mg CH4 m−2 d−1 to 220 mg CH4 m−2 d−1 from mid May to mid July. After July, CH4 …


The Fierce Green Fire: Vol. 4 Issue 12, Wofford College Environmental Studies Program Dec 2013

The Fierce Green Fire: Vol. 4 Issue 12, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.


2013 Fall Engr333 Vehicle Poster, 2013 Fall Engr333 Dec 2013

2013 Fall Engr333 Vehicle Poster, 2013 Fall Engr333

ENGR 333

Waste vegetable oil (WVO) was chosen by the class as the best fuel source for the Calvin Biofuel Vehicle Project. The class then considered vehicle options and selected a lawnmower to be powered by WVO.


2013 Fall Engr333 Fuel And Facilities Poster, 2013 Fall Engr333 Dec 2013

2013 Fall Engr333 Fuel And Facilities Poster, 2013 Fall Engr333

ENGR 333

The objective of the project was to answer the question: “What would it take for Calvin College to operate a biofuel vehicle from campus resources.” The class split into 3 teams:

  • Fuel/Feedstock
  • Facilities/Infrastructure
  • Vehicle


College Of Engineering Senior Design Competition Fall 2013, University Of Nevada, Las Vegas Dec 2013

College Of Engineering Senior Design Competition Fall 2013, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …


Effect Of Embedded Pd Microstructures On The Flat-Band-Voltage Operation Of Room Temperature Zno-Based Liquid Petroleum Gas Sensors, Ghusoon M. Ali, Cody V. Thompson, Ali K. Jasim, Isam M. Abdulbaki, James C. Moore Dec 2013

Effect Of Embedded Pd Microstructures On The Flat-Band-Voltage Operation Of Room Temperature Zno-Based Liquid Petroleum Gas Sensors, Ghusoon M. Ali, Cody V. Thompson, Ali K. Jasim, Isam M. Abdulbaki, James C. Moore

Chemistry

Three methods were used to fabricate ZnO-based room temperature liquid petroleum gas (LPG) sensors having interdigitated metal-semiconductor-metal (MSM) structures. Specifically, devices with Pd Schottky contacts were fabricated with: (1) un-doped ZnO active layers; (2) Pd-doped ZnO active layers; and (3) un-doped ZnO layers on top of Pd microstructure arrays. All ZnO films were grown on p-type Si(111) substrates by the sol-gel method. For devices incorporating a microstructure array, Pd islands were first grown on the substrate by thermal evaporation using a 100 μm mesh shadow mask. We have estimated the sensitivity of the sensors for applied voltage from -5 to …


The Crustal Thickness Of West Antarctica, Julien A. Chaput, Richard C. Aster, Audrey D. Huerta, X. Sun, Andrew Lloyd, Douglas A. Wiens, Andrew Nyblade, Sridhar Anandakrishnan, J. Paul Winberry, Terry Wilson Dec 2013

The Crustal Thickness Of West Antarctica, Julien A. Chaput, Richard C. Aster, Audrey D. Huerta, X. Sun, Andrew Lloyd, Douglas A. Wiens, Andrew Nyblade, Sridhar Anandakrishnan, J. Paul Winberry, Terry Wilson

Geological Sciences Faculty Scholarship

P-to-S receiver functions (PRFs) from the Polar Earth Observing Network (POLENET) GPS and seismic leg of POLENET spanning West Antarctica and the Transantarctic Mountains deployment of seismographic stations provide new estimates of crustal thickness across West Antarctica, including the West Antarctic Rift System (WARS), Marie Byrd Land (MBL) dome, and the Transantarctic Mountains (TAM) margin. We show that complications arising from ice sheet multiples can be effectively managed and further information concerning low-velocity subglacial sediment thickness may be determined, via top-down utilization of synthetic receiver function models. We combine shallow structure constraints with the response of deeper layers using a …


Cosm News, Georgia Southern University Dec 2013

Cosm News, Georgia Southern University

College of Science & Mathematics: News & Publications (2012-2022)

  • Georgia Southern Professors Win Top Regents’ Awards


Polarization-Coupled Transport Behavior In Ultrathin Ferroelectric Heterostructures, Haidong Lu Dec 2013

Polarization-Coupled Transport Behavior In Ultrathin Ferroelectric Heterostructures, Haidong Lu

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Ferroelectric polarization-coupled resistive switching behavior in ferroelectric tunnel junctions (FTJs), the tunneling electroresistance (TER) effect, is a recently predicted new phenomenon, which attracts interest due to potential application in the next generation non-volatile ferroelectric random access memories (FeRAMs). In this dissertation, we demonstrate the TER effect in FTJ devices by means of scanning probe microscopy (SPM) techniques. We have investigated several device configurations for enhancement of polarization stability and for demonstration of the resistive switching behavior: (i) using the SPM probe as a top electrode; (ii) using heterostructures with engineered interfacial atomic terminations; (iii) using metal electrodes; (iv) adding an …


Asymptotic Multi-Layer Analysis Of Wind Over Unsteady Monochromatic Surface Waves, Shahrdad Sajjadi, Julian Hunt, Frederique Drullion Dec 2013

Asymptotic Multi-Layer Analysis Of Wind Over Unsteady Monochromatic Surface Waves, Shahrdad Sajjadi, Julian Hunt, Frederique Drullion

Publications

Asymptotic multi-layer analyses and computation of solutions for turbulent flows over steady and unsteady monochromatic surface wave are reviewed, in the limits of low turbulent stresses and small wave amplitude. The structure of the flow is defined in terms of asymptotically-matched thin-layers, namely the surface layer and a critical layer, whether it is ‘elevated’ or ‘immersed’, corresponding to its location above or within the surface layer. The results particularly demonstrate the physical importance of the singular flow features and physical implications of the elevated critical layer in the limit of the unsteadiness tending to zero. These agree with the variational …


Differentiation Of Solutions Of Second-Order Bvps With Integral Boundary Conditions, Alfredo Janson, Bibi Juman Dec 2013

Differentiation Of Solutions Of Second-Order Bvps With Integral Boundary Conditions, Alfredo Janson, Bibi Juman

Mathematics Colloquium Series

Janson’s and Juman’s research involves differentiating solutions of boundary value problems with integral conditions, as well as showing that the resulting functions solve an associated boundary value problem—called the variational equation—with new integral boundary values.


A Conceptual Model For Federated Authentication In The Cloud, Abdulwahid Al Abdulwahid, Nathan Clarke, Steven Furnell, Ingo Stengel Dec 2013

A Conceptual Model For Federated Authentication In The Cloud, Abdulwahid Al Abdulwahid, Nathan Clarke, Steven Furnell, Ingo Stengel

Australian Information Security Management Conference

Authentication is a key security control for any computing system, whether that is a PC, server, laptop, tablet or mobile phone. However, authentication is traditionally poorly served, with existing implementations falling foul of a variety of weaknesses. Passwords are poorly selected, reused and shared (to name but a few). Research has suggested novel approaches to authentication such as transparent authentication and cooperative and distributed authentication. However, these technologies merely focus upon individual platforms rather than providing a universal and federated authentication approach that can be used across technologies and services. The advent of cloud computing, its universal connectivity, scalability and …