Hydrodynamic bead modelling of the 2:1 p50–IκBγ complex

2004 ◽  
Vol 108 (1-3) ◽  
pp. 259-271
Author(s):  
Michaela Smolle ◽  
Ronald T. Hay ◽  
Olwyn Byron
Keyword(s):  
Bead Modelling

Bead modelling and implementation of adaptive MAT path in wire and arc additive manufacturing

2016 ◽  
Vol 39 ◽  
pp. 32-42 ◽  
Author(s):  
Donghong Ding ◽  
Zengxi Pan ◽  
Dominic Cuiuri ◽  
Huijun Li ◽  
Stephen van Duin ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Bead Modelling

Rotne–Prager–Yamakawa approximation for different-sized particles in application to macromolecular bead models

2014 ◽  
Vol 741 ◽  
Author(s):  
P. J. Zuk ◽  
E. Wajnryb ◽  
K. A. Mizerski ◽  
P. Szymczak
Keyword(s):  
Brownian Dynamics ◽  
Ad Hoc ◽  
Positive Definiteness ◽  
Spherical Particles ◽  
Hydrodynamic Properties ◽  
Limiting Behaviour ◽  
Complete Set ◽  
Bead Modelling ◽  
Dynamics Simulations ◽  
Brownian Dynamics Simulations

AbstractThe Rotne–Prager–Yamakawa (RPY) approximation is a commonly used approach to model the hydrodynamic interactions between small spherical particles suspended in a viscous fluid at a low Reynolds number. However, when the particles overlap, the RPY tensors lose their positive definiteness, which leads to numerical problems in the Brownian dynamics simulations as well as errors in calculations of the hydrodynamic properties of rigid macromolecules using bead modelling. These problems can be avoided by using regularizing corrections to the RPY tensors; so far, however, these corrections have only been derived for equal-sized particles. Here we show how to generalize the RPY approach to the case of overlapping spherical particles of different radii and present the complete set of mobility matrices for such a system. In contrast to previous ad hoc approaches, our method relies on the direct integration of force densities over the sphere surfaces and thus automatically provides the correct limiting behaviour of the mobilities for the touching spheres and for a complete overlap, with one sphere immersed in the other one. This approach can then be used to calculate hydrodynamic properties of complex macromolecules using bead models with overlapping, different-sized beads, which we illustrate with an example.

scholarly journals Development of Bead Modelling for Distortion Analysis Induced by Wire Arc Additive Manufacturing using FEM and Experiment

2019 ◽  
Vol 269 ◽  
pp. 05003 ◽  
Author(s):  
Keval P Prajadhiama ◽  
Yupiter HP Manurung ◽  
Zaidi Minggu ◽  
Fetisia HS Pengadau ◽  
Marcel Graf ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computational Time ◽  
Equivalent Material ◽  
Low Carbon ◽  
Robotic Welding ◽  
Product Model ◽  
Rectangular Shape ◽  
Arc Shape ◽  
Bead Modelling ◽  
Wire Arc Additive Manufacturing

In this research, Wire Arc Additive Manufacturing is modelled and simulated to determine the most suitable bead modelling strategy. This analysis is aimed to predict distortion by means of thermomechanical Finite Element Method (FEM). The product model with wire as feedstock on plate as substrate and process simulation are designed in form of multi-layered beads and single string using MSC Marc/Mentat. This research begins with finding suitable WAAM parameters which takes into account the bead quality. This is done by using robotic welding system with 01.2mm filler wire (AWS A5.28 : ER80SNi1), shielding gas (80% Ar/ 20% CO2) and 6mm-thick low carbon steel as base plate. Further, modelling as well as simulation are to be conducted with regards to bead spreading of each layers. Two different geometrical modelling regarding the weld bead are modelled which are arc and rectangular shape. Equivalent material properties from database and previous researches are implemented into simulation to ensure a realistic resemblance. It is shown that bead modelling with rectangular shape exhibits faster computational time with less error percentage on distortion result compared to arc shape. Moreover, by using the rectangular shape, the element and meshing are much easier to be designed rather than arc shape bead.

A practical fabrication strategy for wire arc additive manufacturing of metallic parts with wire structures

2021 ◽  
Author(s):  
Ziping Yu ◽  
Zengxi Pan ◽  
Donghong Ding ◽  
Joseph Polden ◽  
Lei Yuan ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Complex Geometry ◽  
Free Form ◽  
Welding Parameter ◽  
High Deposition Rate ◽  
Manufacturing Strategy ◽  
Environmental Friendliness ◽  
Bead Modelling ◽  
Metallic Parts ◽  
Wire Arc Additive Manufacturing

Abstract Wire Arc Additive Manufacturing (WAAM) is well suited for the manufacture of sizeable metallic workpieces featuring medium-to-high geometrical complexity due to its high deposition rate, low processing conditions limit, and environmental friendliness. To enhance the current capability of the WAAM process for fabricating structures with complex geometry, this paper proposes a robot-based WAAM strategy adapted specifically for fabricating free-form parts with wire structures composed of multiple struts. Contributions in this work include: (i) The study of bead modelling, which establishes optimal welding parameter selection for the process; (ii) The novel manufacturing strategy, including the adaptive slicing methodology and height control system for accurately depositing every single strut; (iii) Detailed manufacturing procedures for multi-strut branch intersections as well as the collision-free path planning to control the overall fabrication process. To verify the effectiveness of this proposed WAAM approach, two complex wire structures were fabricated successfully, indicating the feasibility of the proposed fabrication strategy.

scholarly journals Dummy-atom modelling of stacked and helical nanostructures from solution scattering data

IUCrJ ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 390-401 ◽  
Author(s):  
Max Burian ◽  
Heinz Amenitsch
Keyword(s):  
Building Block ◽  
User Interaction ◽  
Shape Reconstruction ◽  
Analytical Models ◽  
Structural Motif ◽  
Scattering Data ◽  
Data Sets ◽  
Dummy Atom ◽  
Full Structure ◽  
Bead Modelling

The availability of dummy-atom modelling programs to determine the shape of monodisperse globular particles from small-angle solution scattering data has led to outstanding scientific advances. However, there is no equivalent procedure that allows modelling of stacked, seemingly endless structures, such as helical systems. This work presents a bead-modelling algorithm that reconstructs the structural motif of helical and rod-like systems. The algorithm is based on a `projection scheme': by exploiting the recurrent nature of stacked systems, such as helices, the full structure is reduced to a single building-block motif. This building block is fitted by allowing random dummy-atom movements without an underlying grid. The proposed method is verified using a variety of analytical models, and examples are presented of successful shape reconstruction from experimental data sets. To make the algorithm available to the scientific community, it is implemented in a graphical computer program that encourages user interaction during the fitting process and also includes an option for shape reconstruction of globular particles.

scholarly journals Hydrolysable ATP is a requirement for the correct interaction of molecular chaperonins cpn60 and cpn10

2002 ◽  
Vol 364 (3) ◽  
pp. 849-855 ◽  
Author(s):  
Chris WALTERS ◽  
Neil ERRINGTON ◽  
Arther J. ROWE ◽  
Stephen E. HARDING
Keyword(s):  
Light Scattering ◽  
Molecular Chaperone ◽  
Analytical Ultracentrifugation ◽  
Sedimentation Velocity ◽  
Dilute Solution ◽  
Binding Ability ◽  
Absorption Spectrophotometry ◽  
Molecular Hydrodynamic ◽  
Atp Analogues ◽  
Bead Modelling

Over recent years the binding ability of the molecular chaperone cpn60 (GroEL14) and its co-chaperone cpn10 (GroES7) has been reported to occur under an assortment of specific conditions from the use of non-hydrolysable ATP analogues (namely adenosine 5′-[γ-thio]triphosphate) to requiring hydrolysable ATP for any interaction to occur. We have investigated this further using the molecular hydrodynamic methods (hydrodynamic bead modelling, sedimentation-velocity analytical ultracentrifugation and dynamic light-scattering), allowing the process to be followed under physiologically relevant dilute solution conditions, combined with absorption spectrophotometry to determine GroES7—GroEL14 interaction through the rate inhibition of the cpn60's ATPase activity by GroES7. The results found here indicate that the presence of hydrolysable ATP is required to facilitate correct GroES7 interaction with GroEL14 in solution.

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