1,098 research outputs found
Innovative all composite multi-pultrusion truss system for stressed arch deployable shelters
Trusses are one of the successful structural forms that have been utilised, at extended scale, since the nineteen century. Fibre composite materials are relatively new to civil engineering applications. The increased interest in using composites in civil applications can be attributed to advantages when compared to other construction materials that offset their associated costs. Using conventional approaches for truss systems in composite materials can undermine their efficiency. This is mainly due to concentration of stresses at connections which usually govern the truss design.
The Military Modular Shelter System (M2S2) initiative is a research project that aims to develop a fibre composite re-deployable arched shelter system with rigid PVC or fabric cladding. The main frames are formed from modular fibre composite panels that are connected and stressed into position by prestressing cables. Different geometries can be obtained using this system by changing the number of panels per frame and the packer sizes between panels.
This paper presents the development and testing of innovative fibre composite truss modules that were investigated as part of this project. The truss system is based on using multi-pultrusion sections for the chord and vertical members. Truss bracing is provided by a double skin laminated web. This structure offers many advantages including semi-ductile failure that occurred outside the joint area and ease of manufacturing. In spite of being developed for the M2S2 system, the concept is similarly applicable as a general purpose truss system
Rate constants for diffusive processes by partial path sampling
We introduce a path sampling method for the computation of rate constants for
systems with a highly diffusive character. Based on the recently developed
algorithm of transition interface sampling (TIS) this procedure increases the
efficiency by sampling only parts of complete transition trajectories confined
within a certain region. The algorithm assumes the loss of memory for highly
diffusive progression along the reaction coordinate. We compare the new
technique to the TIS method for a simple diatomic system and show that the
computation time of the new method scales linearly, instead of quadraticaly,
with the length of the diffusive barrier. The validity of the memory loss
assumption is also discussed.Comment: 12 pages, including 8 figures, RevTeX
Ignoring God Triune? The Doctrine of the Trinity in Dutch Theology
Contains fulltext :
82094.pdf (publisher's version ) (Closed access
A Novel Path Sampling Method for the Calculation of Rate Constants
We derive a novel efficient scheme to measure the rate constant of
transitions between stable states separated by high free energy barriers in a
complex environment within the framework of transition path sampling. The
method is based on directly and simultaneously measuring the fluxes through
many phase space interfaces and increases the efficiency with at least a factor
of two with respect to existing transition path sampling rate constant
algorithms. The new algorithm is illustrated on the isomerization of a diatomic
molecule immersed in a simple fluid.Comment: 14 pages, including 13 figures, RevTeX
Openbaarmaking van inspectie-oordelen
Zoals ook elders in dit themanummer aan de orde komt, wordt informatie over de kwaliteit van zorginstellingen en zorgverleners in toenemende mate openbaar gemaakt. Onder andere maakt de Inspectie voor de Gezondheidszorg (IGZ) sinds enkele jaren de namen openbaar van instellingen die onder verscherpt toezicht zijn geplaatst. Komt dat de kwaliteit van de zorg ten goede? In deze opinierubriek legt prof. dr. Gerrit van der Wal, Inspecteur-generaal voor de Gezondheidszorg, uit waarom de IGZ de namen van instellingen met verscherpt toezicht publiceert en welke effecten de IGZ hiermee beoogt te realiseren. Dr. Judith van Erp, criminoloog bij de Erasmus School of Law en auteur van diverse publicaties over openbaarmaking in het toezicht, waaronder het boek Naming en shaming in het markttoezicht (Boom Juridische uitgevers 2009), waarschuwt voor onbedoelde neveneffecten
Elaborating Transition Interface Sampling Methods
We review two recently developed efficient methods for calculating rate
constants of processes dominated by rare events in high-dimensional complex
systems. The first is transition interface sampling (TIS), based on the
measurement of effective fluxes through hypersurfaces in phase space. TIS
improves efficiency with respect to standard transition path sampling (TPS)
rate constant techniques, because it allows a variable path length and is less
sensitive to recrossings. The second method is the partial path version of TIS.
Developed for diffusive processes, it exploits the loss of long time
correlation. We discuss the relation between the new techniques and the
standard reactive flux methods in detail. Path sampling algorithms can suffer
from ergodicity problems, and we introduce several new techniques to alleviate
these problems, notably path swapping, stochastic configurational bias Monte
Carlo shooting moves and order-parameter free path sampling. In addition, we
give algorithms to calculate other interesting properties from path ensembles
besides rate constants, such as activation energies and reaction mechanisms.Comment: 36 pages, 5 figure
Towards structured sharing of raw and derived neuroimaging data across existing resources
Data sharing efforts increasingly contribute to the acceleration of
scientific discovery. Neuroimaging data is accumulating in distributed
domain-specific databases and there is currently no integrated access mechanism
nor an accepted format for the critically important meta-data that is necessary
for making use of the combined, available neuroimaging data. In this
manuscript, we present work from the Derived Data Working Group, an open-access
group sponsored by the Biomedical Informatics Research Network (BIRN) and the
International Neuroimaging Coordinating Facility (INCF) focused on practical
tools for distributed access to neuroimaging data. The working group develops
models and tools facilitating the structured interchange of neuroimaging
meta-data and is making progress towards a unified set of tools for such data
and meta-data exchange. We report on the key components required for integrated
access to raw and derived neuroimaging data as well as associated meta-data and
provenance across neuroimaging resources. The components include (1) a
structured terminology that provides semantic context to data, (2) a formal
data model for neuroimaging with robust tracking of data provenance, (3) a web
service-based application programming interface (API) that provides a
consistent mechanism to access and query the data model, and (4) a provenance
library that can be used for the extraction of provenance data by image
analysts and imaging software developers. We believe that the framework and set
of tools outlined in this manuscript have great potential for solving many of
the issues the neuroimaging community faces when sharing raw and derived
neuroimaging data across the various existing database systems for the purpose
of accelerating scientific discovery
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