Dynamic lattice liquid (DLL) model in computer simulation of the structure and dynamics of polymer condensed systems

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Blim ◽  
Tomasz Kowalczyk
Keyword(s):  
Experimental Validation ◽  
Colloidal Particles ◽  
Excluded Volume ◽  
Linear Polymers ◽  
Simple Liquids ◽  
Structure And Dynamics ◽  
Polymer Liquids ◽  
Bottle Brush ◽  
Condensed Systems ◽  
Good Agreement

AbstractThis review presents the use of Dynamic Lattice Liquid (DLL) model proposed by Pakula and coworkers. In the model polymer liquids are represented as dense systems of macromolecules. The model fulfils requirements of the local continuity and excluded volume conditions. The use of the model for numerical simulations of simple liquids, colloidal particles systems, solutions of linear polymers, branched like bottle-brush or star shaped polymers is described. The use of simulations for the prediction of the properties of the systems and their experimental validation is described. The model is presented as an universal tool for investigation of different systems that provides good agreement between numerical and experimental results for a broad range of the systems and conditions.

Dendronized Polymers: Molecular Objects between Conventional Linear Polymers and Colloidal Particles

2014 ◽  
Vol 3 (10) ◽  
pp. 991-998 ◽  
Author(s):  
A. Dieter Schlüter ◽  
Avraham Halperin ◽  
Martin Kröger ◽  
Dimitris Vlassopoulos ◽  
Gerhard Wegner ◽  
...  
Keyword(s):  
Colloidal Particles ◽  
Linear Polymers ◽  
Dendronized Polymers

scholarly journals Evolution of polymer formation within the actin superfamily

2017 ◽  
Vol 28 (19) ◽  
pp. 2461-2469 ◽  
Author(s):  
Patrick R. Stoddard ◽  
Tom A. Williams ◽  
Ethan Garner ◽  
Buzz Baum
Keyword(s):  
Convergent Evolution ◽  
Atp Hydrolysis ◽  
Linear Polymers ◽  
Related Protein ◽  
Protein Families ◽  
Structure And Dynamics ◽  
Polymer Formation ◽  
Filament Structure ◽  
Related Proteins ◽  
Actin Superfamily

While many are familiar with actin as a well-conserved component of the eukaryotic cytoskeleton, it is less often appreciated that actin is a member of a large superfamily of structurally related protein families found throughout the tree of life. Actin-related proteins include chaperones, carbohydrate kinases, and other enzymes, as well as a staggeringly diverse set of proteins that use the energy from ATP hydrolysis to form dynamic, linear polymers. Despite differing widely from one another in filament structure and dynamics, these polymers play important roles in ordering cell space in bacteria, archaea, and eukaryotes. It is not known whether these polymers descended from a single ancestral polymer or arose multiple times by convergent evolution from monomeric actin-like proteins. In this work, we provide an overview of the structures, dynamics, and functions of this diverse set. Then, using a phylogenetic analysis to examine actin evolution, we show that the actin-related protein families that form polymers are more closely related to one another than they are to other nonpolymerizing members of the actin superfamily. Thus all the known actin-like polymers are likely to be the descendants of a single, ancestral, polymer-forming actin-like protein.

scholarly journals Wind Estimation in the Lower Atmosphere Using Multirotor Aircraft

2017 ◽  
Vol 34 (5) ◽  
pp. 1183-1191 ◽  
Author(s):  
Ross T. Palomaki ◽  
Nathan T. Rose ◽  
Michael van den Bossche ◽  
Thomas J. Sherman ◽  
Stephan F. J. De Wekker
Keyword(s):  
Wind Speed ◽  
Sonic Anemometer ◽  
Unmanned Aircraft ◽  
Lower Atmosphere ◽  
Promising Alternative ◽  
Atmospheric Structure ◽  
Structure And Dynamics ◽  
Sonic Anemometers ◽  
Vertical Profiling ◽  
Good Agreement

AbstractUnmanned aerial vehicles are increasingly used to study atmospheric structure and dynamics. While much emphasis has been on the development of fixed-wing unmanned aircraft for atmospheric investigations, the use of multirotor aircraft is relatively unexplored, especially for capturing atmospheric winds. The purpose of this article is to demonstrate the efficacy of estimating wind speed and direction with 1) a direct approach using a sonic anemometer mounted on top of a hexacopter and 2) an indirect approach using attitude data from a quadcopter. The data are collected by the multirotor aircraft hovering 10 m above ground adjacent to one or more sonic anemometers. Wind speed and direction show good agreement with sonic anemometer measurements in the initial experiments. Typical errors in wind speed and direction are smaller than 0.5 and 30°, respectively. Multirotor aircraft provide a promising alternative to traditional platforms for vertical profiling in the atmospheric boundary layer, especially in conditions where a tethered balloon system is typically deployed.

scholarly journals Coupled Dynamics of Cable-Harnessed Structures: Experimental Validation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Karthik Yerrapragada ◽  
Armaghan Salehian
Keyword(s):  
Experimental Study ◽  
Partial Differential Equations ◽  
Frequency Response ◽  
Experimental Validation ◽  
Response Functions ◽  
Beam Structure ◽  
Coupled Dynamics ◽  
Coupled Partial Differential Equations ◽  
Offset Distance ◽  
Good Agreement

The experimental study and model validations for the coupled dynamics of a cable-harnessed beam structure are presented. The system under consideration consists of multiple pretensioned cables attached along the length of the host beam structure positioned at an offset distance from the beam centerline. Analytical model presented by the coupled partial differential equations (PDEs) for various coordinates of vibrations is found, and the displacement frequency response functions (FRFs) obtained for both Euler–Bernoulli and Timoshenko-based models are compared to those from the experiments for validation. The results are shown to be in very good agreement with the experiments.

Experimental Validation of a Dynamic Model for Flexible Link Mechanisms

2001 ◽  
Author(s):  
R. Caracciolo ◽  
A. Gasparetto ◽  
A. Trevisani
Keyword(s):  
Mathematical Model ◽  
Experimental Validation ◽  
Numerical Results ◽  
Test Case ◽  
Planar Mechanisms ◽  
Transient Period ◽  
Element Approach ◽  
Multi Body ◽  
The Mathematical Model ◽  
Good Agreement

Abstract This paper presents an experimental validation of a finite element approach for the dynamic analysis of flexible multi-body planar mechanisms. The mathematical model employed accounts for mechanism geometric and inertial non-linearities and considers coupling effects among rigid-body and elastic motion. A flexible five-bar linkage actuated by two electric motors is employed as a test case. Experimentally determined link absolute deformations are compared with the numerical results obtained simulating the system dynamic behavior through the mathematical model. The experimental and numerical results are in good agreement especially after the very first transient period.

(Post-) Genomic approaches to tackle drug resistance in Leishmania

Parasitology ◽  
2013 ◽  
Vol 140 (12) ◽  
pp. 1492-1505 ◽  
Author(s):  
MAYA BERG ◽  
AN MANNAERT ◽  
MANU VANAERSCHOT ◽  
GERT VAN DER AUWERA ◽  
JEAN-CLAUDE DUJARDIN
Keyword(s):  
Drug Resistance ◽  
Experimental Validation ◽  
Genome Structure ◽  
Acquired Resistance ◽  
Deep Understanding ◽  
Neglected Diseases ◽  
Clear Definition ◽  
Structure And Dynamics ◽  
Definition Of ◽  
Versus Treatment

SUMMARYLeishmaniasis, like other neglected diseases is characterized by a small arsenal of drugs for its control. To safeguard the efficacy of current drugs and guide the development of new ones it is thus of utmost importance to acquire a deep understanding of the phenomenon of drug resistance and its link with treatment outcome. We discuss here how (post-)genomic approaches may contribute to this purpose. We highlight the need for a clear definition of the phenotypes under consideration: innate and acquired resistance versus treatment failure. We provide a recent update of our knowledge on the Leishmania genome structure and dynamics, and compare the contribution of targeted and untargeted methods for the understanding of drug resistance and show their limits. We also present the main assays allowing the experimental validation of the genes putatively involved in drug resistance. The importance of analysing information downstream of the genome is stressed and further illustrated by recent metabolomics findings. Finally, the attention is called onto the challenges for implementing the acquired knowledge to the benefit of the patients and the population at risk.

Experimental Validation of the Addition Principle for Pulsating Flow in Close-Coupled Catalyst Manifolds

2006 ◽  
Vol 128 (4) ◽  
pp. 656-670 ◽  
Author(s):  
Tim Persoons ◽  
Ad Hoefnagels ◽  
Eric Van den Bulck
Keyword(s):  
Experimental Validation ◽  
Engine Speed ◽  
Reverse Flow ◽  
Pulsating Flow ◽  
Exhaust Manifold ◽  
Flow Uniformity ◽  
Blow Down ◽  
Time Resolved ◽  
Flow Through ◽  
Good Agreement

Designing an exhaust manifold with close-coupled catalyst (CCC) relies heavily on time-consuming transient computional fluid dynamics. The current paper provides experimental validation of the addition principle for pulsating flow in CCC manifolds. The addition principle states that the time-averaged catalyst velocity distribution in pulsating flow equals a linear combination of velocity distributions obtained for steady flow through each of the exhaust runners. A charged motored engine flow rig provides cold pulsating flow in the exhaust manifold featuring blow down and displacement phases, typical of fired engine conditions. Oscillating hot-wire anemometry is used to measure the bidirectional velocity, with a maximum measurable negative velocity of −1m∕s. In part load and zero load conditions, instantaneous reverse flow occurs following the blow-down phase. The two-stage nature of the exhaust stroke combined with strong Helmholtz resonances results in strong fluctuations of the time-resolved mean catalyst velocity. The validity of the addition principle is quantified based on the shape and magnitude similarity between steady and pulsating flow distributions. Appropriate nondimensional groups are used to characterize the flow and quantify the similarity. Statistical significances are provided for the addition principle’s validity. The addition principle is valid when the nondimensional scavenging number S exceeds a critical value Scrit, corresponding to cases of low engine speed and/or high flow rate. This study suggests that the CCC manifold efficiency with respect to catalyst flow uniformity could be quantified using a single scalar parameter, i.e., Scrit. The results from the current study are discussed with respect to previously reported results. The combined results are in good agreement and provide a thorough statistically founded experimental validation of the addition principle, based on a broad applicability range.

Numerical and Experimental Examination of Ballistic System Subjected to IED Explosion

2014 ◽  
Vol 224 ◽  
pp. 276-285 ◽  
Author(s):  
Paweł Dybcio ◽  
Wiesław Barnat
Keyword(s):  
Blast Wave ◽  
Experimental Validation ◽  
Computational Analysis ◽  
Time Integration ◽  
Numerical Data ◽  
Integration Scheme ◽  
Standard Level ◽  
Time Integration Scheme ◽  
Level 1 ◽  
Good Agreement

This article presents results of experimental validation of complex phenomenon of blast wave and fragment impact on protective panel. Protective panel was made of HTK900K steel and Dyneema HB50 polyethylene. Standard level 1 IED surrogate was used. Test was conducted with regards to NATO STANAG 4569 and NATO AEP 55 standardizations. Computational analysis was performed using LS-DYNA code using explicit time integration scheme. Properties of steel, polyethylene and glue were obtained during laboratory tests. Steel was modeled using simplified Johnson-Cook model whereas polyethylene was modeled as composite material. Both blast wave and fragment impact was implemented in simulation. Good agreement between experimental and numerical data was obtained.

Internal structure and dynamics of dilute linear polymers

1992 ◽  
Vol 25 (18) ◽  
pp. 4635-4641 ◽  
Author(s):  
James E. Martin ◽  
Jess P. Wilcoxon ◽  
Judy Odinek
Keyword(s):  
Internal Structure ◽  
Linear Polymers ◽  
Structure And Dynamics
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