Phase Transition And Surface Sublimation Of A Mobile Potts Model, 2015 Cleveland State University

#### Phase Transition And Surface Sublimation Of A Mobile Potts Model, A. Bailly Reyre, H. T. Diep, M. Kaufman

*Miron Kaufman*

We study in this paper the phase transition in a mobile Potts model by the use of Monte Carlo simulation. The mobile Potts model is related to a diluted Potts model, which is also studied here by a mean-field approximation. We consider a lattice where each site is either vacant or occupied by a q-state Potts spin. The Potts spin can move from one site to a nearby vacant site. In order to study the surface sublimation, we consider a system of Potts spins contained in a recipient with a concentration c defined as the ratio of the number of ...

Identifying Student Difficulties With Heat Engines, Entropy, And The Carnot Cycle, 2015 Rowan University

#### Identifying Student Difficulties With Heat Engines, Entropy, And The Carnot Cycle, Trevor I. Smith, Warren M. Christensen, Donald B. Mountcastle, John R. Thompson

*Physics and Astronomy Faculty Scholarship*

We report on several specific student difficulties regarding the second law of thermodynamics in the context of heat engines within upper-division undergraduate thermal physics courses. Data come from ungraded written surveys, graded homework assignments, and videotaped classroom observations of tutorial activities. Written data show that students in these courses do not clearly articulate the connection between the Carnot cycle and the second law after lecture instruction. This result is consistent both within and across student populations. Observation data provide evidence for myriad difficulties related to entropy and heat engines, including students’ struggles in reasoning about situations that are physically impossible ...

Student Understanding Of The Boltzmann Factor, 2015 Rowan University

#### Student Understanding Of The Boltzmann Factor, Trevor I. Smith, Donald B. Mountcastle, John R. Thompson

*Physics and Astronomy Faculty Scholarship*

We present results of our investigation into student understanding of the physical significance and utility of the Boltzmann factor in several simple models. We identify various justifications, both correct and incorrect, that students use when answering written questions that require application of the Boltzmann factor. Results from written data as well as teaching interviews suggest that many students can neither recognize situations in which the Boltzmann factor is applicable nor articulate the physical significance of the Boltzmann factor as an expression for multiplicity, a fundamental quantity of statistical mechanics. The specific student difficulties seen in the written data led us ...

Thermodynamic Effects Of A Local Bell State Projection Interaction In A One-Dimensional Dynamic Spin System, 2015 California Polytechnic State University, San Luis Obispo

#### Thermodynamic Effects Of A Local Bell State Projection Interaction In A One-Dimensional Dynamic Spin System, Nickolas H. Pilgram

*Physics*

No abstract provided.

Statistical Biophysics Blog: More Is Better: The Trajectory Ensemble Picture, 2015 Oregon Health & Science University

#### Statistical Biophysics Blog: More Is Better: The Trajectory Ensemble Picture, Daniel M. Zuckerman

*Scholar Archive*

The trajectory ensemble is fundamental in statistical physics and relatively easy to understand. It is also information-rich, as both equilibrium and non-equilibrium observables may be derived from it.

Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, 2015 AAR Aerospace Consulting, LLC

#### Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, Nihad E. Daidzic, Ph.D.,

*International Journal of Aviation, Aeronautics, and Aerospace*

Both, a global isothermal temperature model and a nonlinear quadratic temperature model of the ISA was developed and presented here. Constrained optimization techniques in conjunction with the least-square-root approximations were used to design best-fit isothermal models for ISA pressure and density changes up to 47 geopotential km for NLPAM, and 86 orthometric km for ISOAM respectively. The mass of the dry atmosphere and the relevant fractional-mass scale heights have been computed utilizing the very accurate eight-point Gauss-Legendre numerical quadrature for both ISOAM and NLPAM. Both, the ISOAM and the NLPAM represent viable alternatives to ISA in many practical applications and ...

Gait Transition Dynamics Are Modulated By Experimental Protocol, 2015 University of Connecticut - Storrs

#### Gait Transition Dynamics Are Modulated By Experimental Protocol, Mohammad Abdolvahab, Jason Gordon

*Mohammad Abdolvahab*

No abstract provided.

Statistical Biophysics Blog: Everything Is Markovian; Nothing Is Markovian, 2015 Oregon Health & Science University

#### Statistical Biophysics Blog: Everything Is Markovian; Nothing Is Markovian, Daniel M. Zuckerman

*Scholar Archive*

Most behavior, observed via a subset of coordinates or discretized states, should not be Markovian even though the underlying dynamics generally will be.

Temperature Dependent Surface Reconstruction Of Freely Suspended Films Of 4-N-Heptyloxybenzylidene-4-N-Heptylaniline, 2015 Lawrence University

#### Temperature Dependent Surface Reconstruction Of Freely Suspended Films Of 4-N-Heptyloxybenzylidene-4-N-Heptylaniline, Daniel E. Martinez Zambrano

*Lawrence University Honors Projects*

Surfaces of freely suspended thick films of 4-n-heptyloxybenzylidene-4-n-heptylaniline (7O.7) in the crystalline-B phase have been imaged using non-contact mode atomic force microscopy. Steps are observed on the surface of the film with a height of 3.0 +/- 0.1 nm corresponding to the upright molecular length of 7O.7. In addition, we find that the step width varies with temperature between 56 and 59 degrees C. The steps are many times wider than the molecular length, suggesting that the steps are not on the surface but instead originate from edge dislocations in the interior. Using a strain model for ...

Time-Frequency Analysis Reveals Pairwise Interactions In Insect Swarms, 2015 Gettysburg College

#### Time-Frequency Analysis Reveals Pairwise Interactions In Insect Swarms, James G. Puckett, Rui Ni, Nicholas T. Ouellette

*Physics and Astronomy Faculty Publications*

The macroscopic emergent behavior of social animal groups is a classic example of dynamical self-organization, and is thought to arise from the local interactions between individuals. Determining these interactions from empirical data sets of real animal groups, however, is challenging. Using multicamera imaging and tracking, we studied the motion of individual flying midges in laboratory mating swarms. By performing a time-frequency analysis of the midge trajectories, we show that the midge behavior can be segmented into two distinct modes: one that is independent and composed of low-frequency maneuvers, and one that consists of higher-frequency nearly harmonic oscillations conducted in synchrony ...

Application Of Transfer Matrix Method To Secondharmonic Generation In Nonlinear Photonic Bandgap Structures: Oblique Incidence, 2015 University of Dayton

#### Application Of Transfer Matrix Method To Secondharmonic Generation In Nonlinear Photonic Bandgap Structures: Oblique Incidence, Han Li

*Han Li*

No abstract provided.

Persistent Population Biases In Branching Random Walk Algorithms, 2015 College of William and Mary

#### Persistent Population Biases In Branching Random Walk Algorithms, David J. Geroski

*Undergraduate Honors Theses*

We explore the existence of a residual population bias in Diffusion Monte Carlo algorithms. We develop a model problem, which mimics the single-particle, one dimensional simple harmonic oscillator of unitary ground state energy, to study these biases. We then apply an importance sampling algorithms with a population of a single random walker to calculate the ground state energy and wavefunction of our modeled system in cases of both perfect and imperfect importance sampling. In the former case, we perfectly calculate both the ground state energy and corresponding wavefunction of our system, thus validating our calculations and assumed answer. In the ...

Statistical Biophysics Blog: “Proof” Of The Hill Relation Between Probability Flux And Mean First-Passage Time, 2015 Oregon Health & Science University

#### Statistical Biophysics Blog: “Proof” Of The Hill Relation Between Probability Flux And Mean First-Passage Time, Daniel M. Zuckerman

*Scholar Archive*

The “Hill relation” is a key result for anyone interested in calculating rates from trajectories of any kind, whether molecular simulations or otherwise. I am not aware of any really clear explanation, including Hill’s original presentation. Hopefully this go-around will make sense.

Statistical Biophysics Blog: A Hello: The Point Of This Blog, 2015 Oregon Health & Science University

#### Statistical Biophysics Blog: A Hello: The Point Of This Blog, Daniel M. Zuckerman

*Scholar Archive*

No abstract provided.

The Impact Of Imperfect Information On Network Attack, 2015 Boise State University

#### The Impact Of Imperfect Information On Network Attack, A. Melchionna, Jesus Caloca, S. Squires, T. Antonsen, E. Ott, M. Girvan

*McNair Scholars Research Journal*

This paper explores the effectiveness of network attack when the attacker has imperfect information about the network. For Erdös-Rényi networks, we observe that dynamical importance and betweenness centrality-based attacks are surprisingly robust to the presence of a moderate amount of imperfect information and are more effective compared with simpler degree-based attacks even at moderate levels of network information error. In contrast, for scale-free networks the effectiveness of attack is much less degraded by a moderate level of information error. Furthermore, in the Erdös-Rényi case the effectiveness of network attack is much more degraded by missing links as compared with the ...

Sucralose Destabilization Of Protein Structure, 2015 Wesleyan University

#### Sucralose Destabilization Of Protein Structure, Christina M. Othon

*Christina M Othon*

Sucralose is a commonly employed artificial sweetener that behaves very differently than its natural disaccharide counterpart, sucrose, in terms of its interaction with biomolecules. The presence of sucralose in solution is found to destabilize the native structure of two model protein systems: the globular protein bovine serum albumin and an enzyme staphylococcal nuclease. The melting temperature of these proteins decreases as a linear function of sucralose concentration. We correlate this destabilization to the increased polarity of the molecule. The strongly polar nature is manifested as a large dielectric friction exerted on the excited-state rotational diffusion of tryptophan using time-resolved fluorescence ...

Discrete Excitation Spectrum Of A Classical Harmonic Oscillator In Zero-Point Radiation, 2015 Texas A & M University - College Station

#### Discrete Excitation Spectrum Of A Classical Harmonic Oscillator In Zero-Point Radiation, Wayne Cheng-Wei Huang, Herman Batelaan

*Faculty Publications, Department of Physics and Astronomy*

We report that upon excitation by a single pulse, a classical harmonic oscillator immersed in the classical electromagnetic zero-point radiation exhibits a discrete harmonic spectrum in agreement with that of its quantum counterpart. This result is interesting in view of the fact that the vacuum field is needed in the classical calculation to obtain the agreement.

Second-Harmonic Generation At Oblique Angles In Photonic Bandgap Structures, 2015 University of Dayton

#### Second-Harmonic Generation At Oblique Angles In Photonic Bandgap Structures, Han Li

*Han Li*

No abstract provided.

Second Harmonic Generation At Oblique Angles In Photonic Bandgap Structures, 2015 University of Dayton

#### Second Harmonic Generation At Oblique Angles In Photonic Bandgap Structures, Han Li

*Han Li*

No abstract provided.

Charged Particle Dynamics In The Magnetic Field Of A Long Straight Current-Carrying Wire, 2015 Xavier University - Cincinnati

#### Charged Particle Dynamics In The Magnetic Field Of A Long Straight Current-Carrying Wire, M. Fatuzzo, A. Prentice, T. Toepker

*Faculty Scholarship*

The article discusses the concept behind motion of a charged particle in a non-uniform filed of a wire carrying current. Topics discussed include possible types of motion in a current carrying field**,** vector analysis of velocity and magnetic field of the particle and Coupled differential equations.