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Articles 1531 - 1560 of 6056

Full-Text Articles in Physical Sciences and Mathematics

Toward Dmd Illuminated Spatial-Temporal Modulated Thermography, Joshua D. Pribe, Srinivas Chakravarthi Thandu, Zhaozheng Yin, Edward C. Kinzel May 2016

Toward Dmd Illuminated Spatial-Temporal Modulated Thermography, Joshua D. Pribe, Srinivas Chakravarthi Thandu, Zhaozheng Yin, Edward C. Kinzel

Computer Science Faculty Research & Creative Works

This paper reports on a system using a Digital Micromirror Device (DMD) to modulate a near-infrared laser source spatially and temporally. The DMD can produce an arbitrary heat source varying both spatially and temporally over the target. When the thermal response of the target surface is recorded using a thermal imager, this provides new possibilities in subsurface defect detection, partially with regard to features whose orientation does not allow them to be resolved using conventional thermographic inspection techniques. In this respect it is similar to conventional focused spot detection approaches; however, the DMD allows the signal to be frequency/phase multiplexed …

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Employing Synergetic Effect Of Doping And Thin Film Coating To Boost The Performance Of Lithium-Ion Battery Cathode Particles, Rajankumar L. Patel, Yingbing Jiang, Amitava Choudhury, Xinhua Liang May 2016

Employing Synergetic Effect Of Doping And Thin Film Coating To Boost The Performance Of Lithium-Ion Battery Cathode Particles, Rajankumar L. Patel, Yingbing Jiang, Amitava Choudhury, Xinhua Liang

Chemistry Faculty Research & Creative Works

Atomic layer deposition (ALD) has evolved as an important technique to coat conformal protective thin films on cathode and anode particles of lithium ion batteries to enhance their electrochemical performance. Coating a conformal, conductive and optimal ultrathin film on cathode particles has significantly increased the capacity retention and cycle life as demonstrated in our previous work. In this work, we have unearthed the synergetic effect of electrochemically active iron oxide films coating and partial doping of iron on LiMn1.5 Ni0.5O4 (LMNO) particles. The ionic Fe penetrates into the lattice structure of LMNO during the ALD process. …

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Extracting Conformational Structure Information Of Benzene Molecules Via Laser-Induced Electron Diffraction, Yuta Ito, Chuncheng Wang, Anh-Thu Le, Misaki Okunishi, Dajun Ding, C. D. Lin, Kiyoshi Ueda May 2016

Extracting Conformational Structure Information Of Benzene Molecules Via Laser-Induced Electron Diffraction, Yuta Ito, Chuncheng Wang, Anh-Thu Le, Misaki Okunishi, Dajun Ding, C. D. Lin, Kiyoshi Ueda

Physics Faculty Research & Creative Works

We have measured the angular distributions of high energy photoelectrons of benzene molecules generated by intense infrared femtosecond laser pulses. These electrons arise from the elastic collisions between the benzene ions with the previously tunnel-ionized electrons that have been driven back by the laser field. Theory shows that laser-free elastic differential cross sections (DCSs) can be extracted from these photoelectrons, and the DCS can be used to retrieve the bond lengths of gas-phase molecules similar to the conventional electron diffraction method. From our experimental results, we have obtained the C-C and C-H bond lengths of benzene with a spatial resolution …

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Big Changes For Small Noncovalent Dimers: Revisiting The Potential Energy Surfaces Of (P2)2 And (Pccp)2 With Ccsd(T) Optimizations And Vibrational Frequencies, Eric Van Dornshuld, Gregory S. Tschumper Apr 2016

Big Changes For Small Noncovalent Dimers: Revisiting The Potential Energy Surfaces Of (P2)2 And (Pccp)2 With Ccsd(T) Optimizations And Vibrational Frequencies, Eric Van Dornshuld, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

This article details the re-examination of low-lying stationary points on the potential energy surfaces (PESs) of two challenging noncovalent homogeneous dimers, (P2)2 and (PCCP)2. The work was motivated by the rather large differences between MP2 and CCSD(T) energetics that were recently reported for these systems (J. Comput. Chem. 2014, 35, 479-487). The current investigation reveals significant qualitative and quantitative changes when the CCSD(T) method is used to characterize the stationary points instead of MP2. For example, CCSD(T) optimizations and harmonic vibrational frequency computations with the aug-cc-pVTZ basis set indicate that the parallel-slipped (PS) structure is …

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Expansion Of The Tetragonal Magnetic Phase With Pressure In The Iron Arsenide Superconductor Ba₁₋ₓkₓfe₂As₂, E. Hassinger, G. Gredat, F. Valade, S. René De Cotret, O. Cyr-Choinière, A. Juneau-Fecteau, J. Ph Reid, Hyunsoo Kim, M. A. Tanatar, For Full List Of Authors, See Publisher's Website. Apr 2016

Expansion Of The Tetragonal Magnetic Phase With Pressure In The Iron Arsenide Superconductor Ba₁₋ₓkₓfe₂As₂, E. Hassinger, G. Gredat, F. Valade, S. René De Cotret, O. Cyr-Choinière, A. Juneau-Fecteau, J. Ph Reid, Hyunsoo Kim, M. A. Tanatar, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

In the temperature-concentration phase diagram of most iron-based superconductors, antiferromagnetic order is gradually suppressed to zero at a critical point, and a dome of superconductivity forms around that point. The nature of the magnetic phase and its fluctuations is of fundamental importance for elucidating the pairing mechanism. In Ba1-xKxFe2As2 and Ba1-xNaxFe2As2, it has recently become clear that the usual stripelike magnetic phase, of orthorhombic symmetry, gives way to a second magnetic phase, of tetragonal symmetry, near the critical point, in the range from x = …

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The Anisotropy Of Hexagonal Close-Packed And Liquid Interface Free Energy Using Molecular Dynamics Simulations Based On Modified Embedded-Atom Method, Ebrahim Asadi, Mohsen Asle Zaeem Apr 2016

The Anisotropy Of Hexagonal Close-Packed And Liquid Interface Free Energy Using Molecular Dynamics Simulations Based On Modified Embedded-Atom Method, Ebrahim Asadi, Mohsen Asle Zaeem

Materials Science and Engineering Faculty Research & Creative Works

This work aims to comprehensively study the anisotropy of the hexagonal close-packed (HCP)-liquid interface free energy using molecular dynamics (MD) simulations based on the modified-embedded atom method (MEAM). As a case study, all the simulations are performed for Magnesium (Mg). The solid-liquid coexisting approach is used to accurately calculate the melting point and melting properties. Then, the capillary fluctuation method (CFM) is used to determine the HCP-liquid interface free energy (γ) and anisotropy parameters. In CFM, a continuous order parameter is employed to accurately locate the HCP-liquid interface location, and the HCP symmetry-adapted spherical harmonics are used to expand γ …

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The Ideal And Real Gas Heat Capacity Of Potassium Atoms At High Temperatures, Louis Biolsi, Michael Biolsi Apr 2016

The Ideal And Real Gas Heat Capacity Of Potassium Atoms At High Temperatures, Louis Biolsi, Michael Biolsi

Chemistry Faculty Research & Creative Works

The Ideal Gas Heat Capacity, Cp, of Potassium Atoms is Calculated to High Temperatures using Statistical Mechanics. Since There Are a Large Number of Electronic Energy Levels in the Partition Function (Boltzmann Sum) Below the First Ionization Potential, the Partition Function and Cp will become very large as the Temperature Increases Unless the Number of Energy Levels Contributing to the Partition Function is Constrained. Two Primary Categories of Arguments Are Used to Do This. First, at High Temperatures, the Increased Size of the Atoms Constrains the Sum (Bethe Method). Second, an Argument based on the Existence of Interacting …

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Evolution Of Stellar-To-Halo Mass Ratio At Z = 0-7 Identified By Clustering Analysis With The Hubble Legacy Imaging And Early Subaru/Hyper Suprime-Cam Survey Data, Yuichi Harikane, Masami Ouchi, Yoshiaki Ono, Surhud More, Shun Saito, For Full List Of Authors, See Publisher's Website. Apr 2016

Evolution Of Stellar-To-Halo Mass Ratio At Z = 0-7 Identified By Clustering Analysis With The Hubble Legacy Imaging And Early Subaru/Hyper Suprime-Cam Survey Data, Yuichi Harikane, Masami Ouchi, Yoshiaki Ono, Surhud More, Shun Saito, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present clustering analysis results from 10,381 Lyman break galaxies (LBGs) at z ∼ 4-7, identified in the Hubble legacy deep imaging and new complimentary large-area Subaru/Hyper Suprime-Cam data. We measure the angular correlation functions of these LBGs at z ∼ 4, 5, 6, and 7 and fit these measurements using halo occupation distribution (HOD) models that provide an estimate of halo masses, Mh ~ (1 - 20 ) x 1011 M⊙. Our Mh estimates agree with those obtained by previous clustering studies in a UV-magnitude versus Mh plane and allow us to calculate …

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A 1-D Coordination Polymer Route To Catalytically Active Co@C Nanoparticles, Anand Pariyar, Siddharth Gopalakrishnan, Joseph Stansbery, Rajankumar L. Patel, Xinhua Liang, Nikolay Nikolaevich Gerasimchuk, Amitava Choudhury Apr 2016

A 1-D Coordination Polymer Route To Catalytically Active Co@C Nanoparticles, Anand Pariyar, Siddharth Gopalakrishnan, Joseph Stansbery, Rajankumar L. Patel, Xinhua Liang, Nikolay Nikolaevich Gerasimchuk, Amitava Choudhury

Chemistry Faculty Research & Creative Works

Pyrolysis of a 1-D polymeric cobalt(ii) coordination complex ([Co(BDC)(Mim)2]n, H2BDC = benzenedicarboxylic acid; Mim = N-methylimidazole) results in the formation of carbon embedded fcc cobalt nanoparticle composites, Co@C. The as-prepared Co@C shows an agglomerated secondary structure with a highly embedded carbon shell comprising of cobalt nanoparticles of 20-100 nm. These Co@C particles show excellent catalytic activity in the reduction of nitrophenol to aminophenol, studied as a model reaction, and evolves as a promising candidate for the gas phase reduction process.

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Gw150914: Implications For The Stochastic Gravitational-Wave Background From Binary Black Holes, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Mar 2016

Gw150914: Implications For The Stochastic Gravitational-Wave Background From Binary Black Holes, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M⊙, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near …

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Gw150914: The Advanced Ligo Detectors In The Era Of First Discoveries, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Mar 2016

Gw150914: The Advanced Ligo Detectors In The Era Of First Discoveries, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10-23√/Hz at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The …

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Dirac Hamiltonian And Reissner-Nordström Metric: Coulomb Interaction In Curved Space-Time, J. H. Noble, Ulrich D. Jentschura Mar 2016

Dirac Hamiltonian And Reissner-Nordström Metric: Coulomb Interaction In Curved Space-Time, J. H. Noble, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We investigate the spin-1/2 relativistic quantum dynamics in the curved space-time generated by a central massive charged object (black hole). This necessitates a study of the coupling of a Dirac particle to the Reissner-Nordström space-time geometry and the simultaneous covariant coupling to the central electrostatic field. The relativistic Dirac Hamiltonian for the Reissner-Nordström geometry is derived. A Foldy-Wouthuysen transformation reveals the presence of gravitational and electrogravitational spin-orbit coupling terms which generalize the Fokker precession terms found for the Dirac-Schwarzschild Hamiltonian, and other electrogravitational correction terms to the potential proportional to αnG, where α is the fine-structure constant and …

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Spatio-Temporal Generalization Of The Harris Criterion And Its Application To Diffusive Disorder, Thomas Vojta, Ronald Dickman Mar 2016

Spatio-Temporal Generalization Of The Harris Criterion And Its Application To Diffusive Disorder, Thomas Vojta, Ronald Dickman

Physics Faculty Research & Creative Works

We investigate how a clean continuous phase transition is affected by spatiotemporal disorder, i.e., by an external perturbation that fluctuates in both space and time. We derive a generalization of the Harris criterion for the stability of the clean critical behavior in terms of the space-time correlation function of the external perturbation. As an application, we consider diffusive disorder, i.e., an external perturbation governed by diffusive dynamics, and its effects on a variety of equilibrium and nonequilibrium critical points. We also discuss the relation between diffusive disorder and diffusive dynamical degrees of freedom in the example of model C of …

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Retrieving Transient Conformational Molecular Structure Information From Inner-Shell Photoionization Of Laser-Aligned Molecules, Xu Wang, Anh-Thu Le, Chao Yu, R. R. Lucchese, C. D. Lin Mar 2016

Retrieving Transient Conformational Molecular Structure Information From Inner-Shell Photoionization Of Laser-Aligned Molecules, Xu Wang, Anh-Thu Le, Chao Yu, R. R. Lucchese, C. D. Lin

Physics Faculty Research & Creative Works

We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. A simple …

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Shape Dependence Of Transmission, Reflection, And Absorption Eigenvalue Densities In Disordered Waveguides With Dissipation, Alexey Yamilov, Sasha Petrenko, Raktim Sarma, Hui Cao Mar 2016

Shape Dependence Of Transmission, Reflection, And Absorption Eigenvalue Densities In Disordered Waveguides With Dissipation, Alexey Yamilov, Sasha Petrenko, Raktim Sarma, Hui Cao

Physics Faculty Research & Creative Works

The universal bimodal distribution of transmission eigenvalues in lossless diffusive systems underpins such celebrated phenomena as universal conductance fluctuations, quantum shot noise in condensed matter physics, and enhanced transmission in optics and acoustics. Here, we show that in the presence of absorption, the density of the transmission eigenvalues depends on the confinement geometry of the scattering media. Furthermore, in an asymmetric waveguide, the densities of the reflection and absorption eigenvalues also depend on the side from which the waves are incident. With increasing absorption, the density of absorption eigenvalues transforms from a single-peak to a double-peak function. Our findings open …

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A Uniform Database Of Teleseismic Shear-Wave Splitting Measurements For The Western And Central United States: December 2014 Update, Bin B. Yang, Kelly H. Liu, Haider H. Dahm, Stephen S. Gao Mar 2016

A Uniform Database Of Teleseismic Shear-Wave Splitting Measurements For The Western And Central United States: December 2014 Update, Bin B. Yang, Kelly H. Liu, Haider H. Dahm, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We present a new version of a shear-wave splitting (SWS) database for the western and central United States (WCUS) using broadband seismic data recorded up to the end of 2014 to update a previous version that used data recorded prior to the end of 2012, when the USArray Transportable Array stations were still recording in the easternmost region of theWCUS. A total of 7452 pairs of additional measurements recorded by 1202 digital broadband seismic stations are obtained, and all the measurements in the previous database are rechecked. The resulting uniform SWS database contains a total of 23,448 pairs of well-defined …

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The Mantle Transition Zone Beneath The Afar Depression And Adjacent Regions: Implications For Mantle Plumes And Hydration, Cory A. Reed, Stephen S. Gao, Kelly H. Liu, Y. Yu Mar 2016

The Mantle Transition Zone Beneath The Afar Depression And Adjacent Regions: Implications For Mantle Plumes And Hydration, Cory A. Reed, Stephen S. Gao, Kelly H. Liu, Y. Yu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Afar Depression and its adjacent areas are underlain by an upper mantle marked by some of the world's largest negative velocity anomalies, which are frequently attributed to the thermal influences of a lower-mantle plume. In spite of numerous studies, however, the existence of a plume beneath the area remains enigmatic, partially due to inadequate quantities of broad-band seismic data and the limited vertical resolution at the mantle transition zone (MTZ) depth of the techniques employed by previous investigations. In this study, we use an unprecedented quantity (over 14 500) of P-to-S receiver functions (RFs) recorded by 139 stations from …

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Graphene Valley, Daniel Applebaum Feb 2016

Graphene Valley, Daniel Applebaum

Missouri S&T’s Peer to Peer

Silicon Valley in northern California is the proverbial hub of technological innovation and industry. Its namesake derives from the fact that silicon acts as the main component in modern electronics; however, a new material called graphene is challenging its role. In its early years of research, it was evident that the qualities of graphene far exceeded expectations. Industries are going mad trying to come up with applications and consumer products. While headway has been made, it is hard to say how long it will take to see products advertising their new graphene capabilities. Before touch screens or graphene-based microprocessors can …

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Innumeracy: The Product Of Misrepresentation, Elizabeth Cundiff Feb 2016

Innumeracy: The Product Of Misrepresentation, Elizabeth Cundiff

Missouri S&T’s Peer to Peer

Innumeracy refers to one’s inability to understand mathematics. Or, more simply, innumeracy is mathematical illiteracy. The main problem with innumeracy is the fact that most of society does not see it as a problem. In fact, many people boast about their innumeracy. Consider a table of five people at a restaurant: they split the check and attempt to calculate the tip. More often than not, at least one individual at the table will joke about the fact that they don’t know how to do make that simple calculation. This flippancy toward the prevalence of mathematics has become an accepted norm, …

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Why Smart Watches Shouldn't Just Become A Trend: Using Smart Watches In The Treatment Of Diabetes, Caelan Rapp Feb 2016

Why Smart Watches Shouldn't Just Become A Trend: Using Smart Watches In The Treatment Of Diabetes, Caelan Rapp

Missouri S&T’s Peer to Peer

As mobile technologies have advanced, the idea of using them in health care applications has expanded greatly. In a 2011 paper by Boulos et al, the impact of mobile technology such as smartphones in health care was examined. Numerous benefits of the implementations were noted, such as how smartphones are able to provide a connection between both doctors and patients due to the network access capabilities of the device. Additionally, using the existing monitoring and sensor technologies on a smartphone can eliminate the need for other external devices, thus reducing the maintenance required by the patient. All in all, keeping …

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The Implications Of Rfid Technology In University Id Cards, Michael Beaver Feb 2016

The Implications Of Rfid Technology In University Id Cards, Michael Beaver

Missouri S&T’s Peer to Peer

Radio frequency identification (RFID) chips have been rising in popularity because of their usefulness and convenience, and have now made their way into the ID cards of universities. An RFID chip is an identification device that, when powered by some nearby source, sends out a signal with information that was stored in the chip. RFID physical security systems work just like a lock and key, with the RFID chip acting as the key. Instead of having a unique pattern, RFID chips have an identification code that is read by the lock. Some RFID chips also hide this code behind a …

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Cs In Hs: Promoting Computer Science Education In High School, Trevor Ross Feb 2016

Cs In Hs: Promoting Computer Science Education In High School, Trevor Ross

Missouri S&T’s Peer to Peer

The world is in the midst of a technology revolution. Each day, new computing devices are introduced, hundreds of new websites are created, and people who have never used the Internet are trying it out for the first time. Nearly two thirds of Americans currently own a smartphone, and that number will only continue to climb (Fingas, 2014). Even cars, thermostats and refrigerators are becoming computerized and connected. This isn't groundbreaking information; most people are aware of this. What isn’t common knowledge, however, is who creates this technology. How does Google always seem to know exactly what you are asking …

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In Crystallo Capture Of A Covalent Intermediate In The Udp-Galactopyranose Mutase Reaction, Ritcha Mehra-Chaudhary, Yumin Dai, Pablo Sobrado, John J. Tanner Feb 2016

In Crystallo Capture Of A Covalent Intermediate In The Udp-Galactopyranose Mutase Reaction, Ritcha Mehra-Chaudhary, Yumin Dai, Pablo Sobrado, John J. Tanner

Chemistry Faculty Research & Creative Works

UDP-galactopyranose mutase (UGM) plays an essential role in galactofuranose biosynthesis in pathogens by catalyzing the conversion of UDP-galactopyranose to UDP-galactofuranose. Here we report the first crystal structure of a covalent intermediate in the UGM reaction. The 2.3 Å resolution structure reveals UDP bound in the active site and galactopyranose linked to the FAD through a covalent bond between the anomeric C of galactopyranose and N5 of the FAD. The structure confirms the role of the flavin as nucleophile and supports the hypothesis that the proton destined for O5 of galactofuranose is shuttled from N5 of the FAD via O4 of …

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Analytical Model For Calibrating Laser Intensity In Strong-Field-Ionization Experiments, Song-Feng. Zhao, Anh-Thu Le, Cheng Jin, Xu Wang, C. D. Lin Feb 2016

Analytical Model For Calibrating Laser Intensity In Strong-Field-Ionization Experiments, Song-Feng. Zhao, Anh-Thu Le, Cheng Jin, Xu Wang, C. D. Lin

Physics Faculty Research & Creative Works

The interaction of an intense laser pulse with atoms and molecules depends extremely nonlinearly on the laser intensity. Yet experimentally there still exists no simple reliable methods for determining the peak laser intensity within the focused volume. Here we present a simple method, based on an improved Perelomov-Popov-Terent'ev model, that would allow the calibration of laser intensities from the measured ionization signals of atoms or molecules. The model is first examined by comparing ionization probabilities (or signals) of atoms and several simple diatomic molecules with those from solving the time-dependent Schrödinger equation. We then show the possibility of using this …

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Neutron And Magnetic Studies Of La₀.₇Sr₀.₃Mn₁₋ₓcrₓo₃(X ≤ 0.7): A Homogeneous Charge-Ordered System, Thomas F. Creel, Jinbo Yang, Satish K. Malik, Sylvio Quezado, Oran Allan Pringle, William B. Yelon, William Joseph James Feb 2016

Neutron And Magnetic Studies Of La₀.₇Sr₀.₃Mn₁₋ₓcrₓo₃(X ≤ 0.7): A Homogeneous Charge-Ordered System, Thomas F. Creel, Jinbo Yang, Satish K. Malik, Sylvio Quezado, Oran Allan Pringle, William B. Yelon, William Joseph James

Physics Faculty Research & Creative Works

Structural and magnetic properties of La0.7Sr0.3Mn1-xCrxO3 (0 < x ≤ 0.7) have been studied in order to determine the effect of substitution of Cr3+ for Mn3+. The data consist of neutron and x-ray powder-diffraction and magnetization measurements. We previously suggested these systems transition from ferromagnetic to antiferromagnetic ordering with the intermediate concentrations containing coexisting ferromagnetic and antiferromagnetic domains. Upon further detailed examination, we find that the neutron data can be fit using a single homogeneous long-range magnetically ordered state and compositionally dependent charge ordering. The magnetic structures are controlled by the competition between Mn-Mn, Mn-Cr, and Cr-Cr interactions (double exchange and superexchange). The metal to …

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Random Field Disorder At An Absorbing State Transition In One And Two Dimensions, Hatem Barghathi, Thomas Vojta Feb 2016

Random Field Disorder At An Absorbing State Transition In One And Two Dimensions, Hatem Barghathi, Thomas Vojta

Physics Faculty Research & Creative Works

We investigate the behavior of nonequilibrium phase transitions under the influence of disorder that locally breaks the symmetry between two symmetrical macroscopic absorbing states. In equilibrium systems such "random-field" disorder destroys the phase transition in low dimensions by preventing spontaneous symmetry breaking. In contrast, we show here that random-field disorder fails to destroy the nonequilibrium phase transition of the one- and two-dimensional generalized contact process. Instead, it modifies the dynamics in the symmetry-broken phase. Specifically, the dynamics in the one-dimensional case is described by a Sinai walk of the domain walls between two different absorbing states. In the two-dimensional case, …

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Metabolic Disorders, Drug Development, Drug Design And Biomarkers, Gjumrakch Aliev, Ramon Cacabelos, V. Prakash Reddy Feb 2016

Metabolic Disorders, Drug Development, Drug Design And Biomarkers, Gjumrakch Aliev, Ramon Cacabelos, V. Prakash Reddy

Chemistry Faculty Research & Creative Works

No abstract provided.

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Astrophysical Implications Of The Binary Black Hole Merger Gw150914, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Feb 2016

Astrophysical Implications Of The Binary Black Hole Merger Gw150914, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

The discovery of the gravitational-wave (GW) source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black hole (BH) systems that inspiral and merge within the age of the universe. Such BH mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively "heavy" BHs (≳25 M⊙) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with …

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Observing Gravitational-Wave Transient Gw150914 With Minimal Assumptions, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Feb 2016

Observing Gravitational-Wave Transient Gw150914 With Minimal Assumptions, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

The gravitational-wave signal GW150914 was first identified on September 14, 2015, by searches for short-duration gravitational-wave transients. These searches identify time-correlated transients in multiple detectors with minimal assumptions about the signal morphology, allowing them to be sensitive to gravitational waves emitted by a wide range of sources including binary black hole mergers. Over the observational period from September 12 to October 20, 2015, these transient searches were sensitive to binary black hole mergers similar to GW150914 to an average distance of ∼600 Mpc. In this paper, we describe the analyses that first detected GW150914 as well as the parameter estimation …

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First Low Frequency All-Sky Search For Continuous Gravitational Wave Signals, J. Aasi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Feb 2016

First Low Frequency All-Sky Search For Continuous Gravitational Wave Signals, J. Aasi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

In this paper we present the results of the first low frequency all-sky search of continuous gravitational wave signals conducted on Virgo VSR2 and VSR4 data. The search covered the full sky, a frequency range between 20 and 128 Hz with a range of spin-down between -1.0 x 10-10 and +1.5 x 10-11 Hz/s, and was based on a hierarchical approach. The starting point was a set of short fast Fourier transforms, of length 8192 s, built from the calibrated strain data. Aggressive data cleaning, in both the time and frequency domains, has been done in order to …

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