... and accelerators, such as MD-GRAPE for molecular dynamics or Clearspeed [148] devices for accelerating floating point computations also show ...
DTIC Science & Technology
We use accelerated molecular dynamics to simulate temperature-programed desorption (TPD) of n-pentane from the basal plane of graphite in the first atomistic simulations to probe TPD over laboratory time scales. Although the simulated TPD spectra agree with experiment, a detailed analysis reveals underlying kinetic phenomena that ...
NASA Astrophysics Data System (ADS)
... a part out of the seeded boron beam which ... and are accelerated towards a stainless steel target coated ... the grid and the quadrupole rods): 36 eV. ...
A biased potential molecular dynamics simulation approach, accelerated molecular dynamics (AMD), has been implemented in the framework of ab initio molecular dynamics for the study of chemical reactions. Using two examples, the double proton transfer ...
PubMed
... Accelerators and Colliders; Beam Dynamics; Applications and New Methods of Acceleration; New Methods; Linear Accelerators and Pulsed Power ...
?-dynamics is an accelerated molecular dynamics method for systems with slow transitions between stable states. Short trajectories are integrated from a transition state separating a reactant state from products. The first trajectory found that leads directly to a product without recrossing the transition state and ...
Accelerated molecular dynamics (aMD) is an enhanced sampling method that improves the conformational space sampling by reducing energy barriers separating different states of a system. Here, we present the implementation of aMD in the parallel simulation program NAMD. We show that aMD simulations performed with NAMD have only a small ...
The melting stage of bulk silicon is studied using classical molecular dynamics simulation. The mean square displacement and diffusion coefficient are focused allowing statistics analysis of the dynamics displacement of each atom. Three stages of the melting processes, premelting, accelerated melting and ...
... Descriptors : *ACCELEROMETERS, *LINEAR ACCELERATORS, USSR, DYNAMICS, IMPACT SHOCK, TRANSLATIONS, ACCELERATION ...
This report contains lecture notes on beam dynamics and acceleration concepts in particle accelerators. (LSP)
Energy Citations Database
Accelerated molecular dynamics simulations are routinely being used to recover the correct canonical probability distributions corresponding to the original potential energy landscape of biomolecular systems. However, the limits of time reweighting, based on transition state theory, in obtaining true kinetic rates from ...
We present the three-dimensional molecular theory of solvation (also known as 3D-RISM) coupled with molecular dynamics (MD) simulation by contracting solvent degrees of freedom, accelerated by extrapolating solvent-induced forces and applying them in large multi-time steps (up to 20 fs) to enable simulation of ...
PubMed Central
We investigate density inversion in vertically oscillated granular layers using continuum and molecular dynamics simulations. Layers of grains atop a plate that is shaken sinusoidally in the direction of gravity will leave the plate at some time in the cycle if the maximum acceleration of the plate amax exceeds the ...
... joint planning, national and international politics ... Beam Dynamics; Accelerator Technology I ... Descriptors : *PARTICLE ACCELERATORS, SYMPOSIA ...
Temperature accelerated dynamics (TAD) simulations allow one to reach long time scales without needing any a priori information on the system dynamics. As a consequence, TAD is a powerful method for simulating complex phenomena where the dynamics is highly unpredictable and the time scale is longer than the one ...
DOE Information Bridge
... Title : Molecular Dynamics and Protein Structure. ... a Workship on Molecular Dynamics of Proteins. ... Dynamics and Structure Refinement; Simulation ...
. Rossler, Ann. NY Acad, Sci. 504, 229 (1987). [6] M. Taiji and T. Ikegami, Physica D134, 253 (1999). [7] R
E-print Network
-grain continuum model that can be parameterized to experiment. The only input required for this approach for example G.A. Shvetsov, V.M. Titov. Railgun accelerators of macroparticles: Hopes and reality. In Megagauss
Hydrodynamic instability of an accelerating ionization front (IF) is investigated with 2D hydrodynamic simulations, including absorption of incident photoionizing photons, recombination in the Hll region, and radiative molecular cooling. When the amplitud...
National Technical Information Service (NTIS)
@mist.i.u-tokyo.acjp Taiji Suzuki1 s-taiji@stat.t.u-tokyo.ac.jp Masashi Sugiyama2 sugi@cs.titech.ac.jp Hisashi Kashima1
The dynamic mechanical properties and molecular weight distribution of two polymer bonded explosives, LX-10-1 and PBX-9502, maintained at 23, 60, and 74 exp 0 C for 3 years were studied. LX-10-1 is 94.5% 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane expl...
A simple method is introduced to achieve efficient random walking in the energy space in molecular dynamics simulations which thus enhances the sampling over a large energy range. The approach is closely related to multicanonical and replica exchange simulation methods in that it allows configurations of the system to be sampled in a wide energy range by ...
We describe a complete implementation of all-atom protein molecular dynamics running entirely on a graphics processing unit (GPU), including all standard force field terms, integration, constraints, and implicit solvent. We discuss the design of our algorithms and important optimizations needed to fully take advantage of a GPU. We evaluate its performance, ...
(3)J scalar couplings report on the conformational averaging of backbone phi angles in peptides and proteins, and therefore represent a potentially powerful tool for studying the details of both structure and dynamics in solution. We have compared an extensive experimental dataset with J-couplings predicted from unrestrained molecular ...
The dynamics of peptides and proteins generated by classical molecular dynamics (MD) is described by using a Markov model. The model is built by clustering the trajectory into conformational states and estimating transition probabilities between the states. Assuming that it is possible to influence the dynamics of ...
A new self-learning algorithm for accelerated dynamics, reconnaissance metadynamics, is proposed that is able to work with a very large number of collective coordinates. Acceleration of the dynamics is achieved by constructing a bias potential in terms of a patchwork of one-dimensional, locally valid collective ...
Molecular dynamics simulations are used to investigate the effects of deformation on the segmental dynamics in an aging polymer glass. Individual particle trajectories are decomposed into a series of discontinuous hops, from which we obtain the full distribution of relaxation times and displacements under three deformation protocols: ...
dynamics of molecular species on the millisecond to femtosecond time scales, 2) photochemistry and relaxation dynamics of molecular species in gases, heterogeneous and...
Science.gov Websites
... Title : Light Scattering Studies of Molecular Dynamics in Molecular Crystals, Liquid Crystals and Polymers for Applications in Chemical Defense. ...
Oxygen vacancy diffusion in rutile was studied by Born-Oppenheimer molecular dynamics techniques in the framework of the semiempirical molecular orbital method MSINDO. Migration of an oxygen vacancy from the rutile (110) surface towards the bulk was simulated. The metadynamics technique was employed to accelerate ...
The use of accelerators such as graphics processing units (GPUs) has become popular in scientific computing applications due to their low cost, impressive floating-point capabilities, high memory bandwidth, and low electrical power requirements. Hybrid high-performance computers, machines with more than one type of floating-point processor, are now becoming more prevalent due ...
We propose a hybrid Monte Carlo (MC) -Molecular Dynamics (MD) technique to study temporally rare event dynamics. By using biased MC sampling (Metropolis-Hastings), we avoid actually visiting low energy states in the MD and instead carry out a quick estimate of the mean escape time to be added to the computer clock. The method does not ...
... Accession Number : ADA101766. Title : Preliminary Study of the Effects of Prolonged Acceleration on Spinal Dynamics of Baboons. 1. Acceleration. ...
... conducted on accelerator facilities, involving zero ... of similar exposures on accelerators. ... IMPACT ACCELERATION, EXPERIMENTAL DATA, HIGH ...
Page 1. Acceleration Properties of Planar Manipulators ... Acceleration Properties of Planar Manipulators from a Dynamic Standpoint 12. ...
The dynamic mechanical response of mesoporous silica with coated inner surfaces confining the glass-forming liquid salol is measured as a function of temperature and frequency (1-100 Hz) for various pore sizes (2.4-7.3 nm). Compared to former results on natural pores, a distinct acceleration of dynamics due to the removal of ...
The author investigates the onset of patterns in vertically oscillated layers of dissipative particles using numerical solutions of continuum equations to Navier-Stokes order. Above a critical accelerational amplitude of the cell, standing waves form stripe patterns which oscillate subharmonically with respect to the cell. Continuum simulations neglecting interparticle ...
... ADD422981. Title : On the Use of Acceleration Waves to Characterize the Dynamic Response of Nonlinear Viscoelastic Materials,. ...
... HUMAN TOLERANCE TO ACCELERATION Prepared under Contract No. ... IN THE ANALYSIS OF HUMAN TOLERANCE TO ACCELERATION ...
The present study investigates the variation of static contact angle of a water droplet in equilibrium with a solid surface in the absence of a body force and the dynamic contact angles of water droplet moving on a solid surface for different characteristic energies using the molecular dynamics simulation. With increasing ...
The dynamic behavior of the oxidation reaction of the Cu surface during the Cu chemical-mechanical polishing (CMP) process was investigated by a novel tight-binding quantum chemical molecular dynamics method. We confirmed that our tight-binding quantum chemical molecular dynamics method with ...
... operational warfare, joint planning, national and international ... of a gas gun accelerator for dynamic warhead tests in the Laboratory for Ballistic ...
... Descriptors : *ACCELERATION, *FINITE ELEMENT ANALYSIS, *SHELTERS, *DYNAMIC LOADS, STRESSES, MATHEMATICAL MODELS, MASS ...
... Accession Number : ADA420006. Title : An Analysis of Airship Acceleration Dynamics for Airborne Gravimetry. Descriptive Note : Rept. ...
The most widely used experimental method for quantifying thermal desorption is temperature-programmed desorption (TPD). Despite its extensive use, interpretation of this experiment can still be controversial. A significant difficulty with interpreting TPD is that this macroscopic experiment offers a limited picture of the underlying microscopic kinetic events. In this work, we use ...
We show that our accelerated molecular-dynamics (MD) approach can extend the time scale in all-atom MD simulations of biopolymers. We also show that this technique allows for the kinetic rate information to be recaptured. In deducing the kinetic rates, the relationship between the local energetic roughness of the potential-energy landscape and the ...
We present the first temperature accelerated dynamics (TAD) simulations of crystal growth. The TAD method [1] allows to extend the simulation time scale so that typical experimental deposition fluxes can be considered. We investigate the initial growth stages of the Ag/Ag(100) system, reaching a total simulation time of ~ 60 s. This represents a boost of ~ ...
The quantum nature of nuclei plays an important role in the accurate modelling of light atoms such as hydrogen, but it is often neglected in simulations due to the high computational overhead involved. It has recently been shown that zero-point energy effects can be included comparatively cheaply in simulations of harmonic and quasiharmonic systems by augmenting classical ...
... ACCELERATED SABOT SYSTEM FOR THE PRODUCTION OF INTENSE MOLECULAR BEAMS. ... promise of producing a molecular beam in the ...
The problem of dynamics optimization for charged particle beams in RFQ accelerators is discussed in this article. The problems of the optimization of particle capture into the acceleration mode are analyzed. Accelerators with low injection energies are considered.
... DYNAMIC RESPONSE, ENERGY TRANSFER, MOLECULAR STRUCTURE, OSCILLATION, VIBRATIONAL SPECTRA, MORSE POTENTIAL. ...
... hydrogen and obtain solid plasmas. ... HYDROGEN, *DYNAMICS, *MOLECULAR PROPERTIES, *SOLIDS, MEASUREMENT, GAMMA ...
The results of molecular dynamics calculations on the equilibrium interface between liquid water and
NASA Technical Reports Server (NTRS)
... Descriptors : *ALUMINUM, *MOLECULAR DYNAMICS, *NICKEL, *NANOPARTICLES, SINTERING, INTERMETALLIC COMPOUNDS ...
The present recursive algorithm for solving molecular systems' dynamical equations of motion employs
... A VALIDATION OF A MOLECULAR DYNAMICS SIMULATION IN DETERMINING THE THERMAL CONDUCTIVITY OF A LA-ZR PYROCHLORE ...
... Title : A Molecular Dynamics Investigation of the Structural Characteristics of Amorphous and Annealed Poly (Vinylidene Fluoride) and Vinylidene ...
The longitudinal particle dynamics in a linear accelerator in the acceleration regime of two waves with multiple frequency without regard for space charge is considered. The accelerating structure of a cavity resonator with 100 MeV drift tubes of is chose...
... Molecular dynamics is used to model the structurc and dynamics of electric double laycr� ... Page 5. Molecular Dynamics Modeling of Electric ...
Graphics processing units (GPUs) have traditionally been used in molecular modeling solely for visualization of molecular structures and animation of trajectories resulting from molecular dynamics simulations. Modern GPUs have evolved into fully programmable, massively parallel co-processors that can now be ...
The compatibility of atomistic simulations with continuum methods is tested by applying empirical molecular dynamics to the diffusion of a boron dopant atom in silicon. Extended timescale simulations of the diffusion path are performed. The analysis of the position of boron during the migration events reveals a preference for a kick-out mechanism. The ...
Recently, we introduced an integrated tempering approach to enhance sampling in the energy and configuration space for large systems. In this paper, we show that this new method has a higher efficiency than bias potential and generalized ensemble methods, such as accelerated molecular dynamics and replica-exchange ...
This paper investigates the dynamics and acceleration levels of a new tethered system for micro- and
