Search results for " Architecture"

Frictional drag between polymer bearing surfaces

2002

Some fundamental features of friction between two polymer bearing surfaces in relative sliding motion are investigated by molecular dynamics simulations. End-tethered and adsorbed polymers are considered under good and poor solvent conditions. The shear stress is measured while varying the solvent's viscosity, surface separation, degree of polymerization and grafting density. For all systems we observe shear thinning that is attributed to the orientation of the chains along the shear direction. This effect is particularly strong for brushes, for which the shear stress during the steady sliding state is mainly determined by the degree of overlap between the brushes.

A fast Monte Carlo algorithm for studying bottle-brush polymers

2011

Obtaining reliable estimates of the statistical properties of complex macromolecules by computer simulation is a task that requires high computational effort as well as the development of highly efficient simulation algorithms. We present here an algorithm combining local moves, the pivot algorithm, and an adjustable simulation lattice box for simulating dilute systems of bottle-brush polymers with a flexible backbone and flexible side chains under good solvent conditions. Applying this algorithm to the bond fluctuation model, very precise estimates of the mean square end-to-end distances and gyration radii of the backbone and side chains are obtained, and the conformational properties of s…

Simulations of phase transitions in macromolecular systems

2002

Abstract The study of phase transitions in concentrated solutions and melts of flexible or stiff polymers is a computational challenge for computer simulations, since already a single polymer coil exhibits nontrivial structure from the scale of a chemical bond (1 A) to the coil radius (100 A), and for the simulation of collective phenomena huge simulation boxes containing many polymers are required. A strategy to deal with this problem is the use of highly coarse-grained models on a lattice, such as the bond fluctuation model. Several studies employing such models will be briefly reviewed, e.g.: temperature-driven isotropic-nematic phase transition in concentrated solutions of semiflexible …

Chain linear dimensions in the surface-enriched layer of polymer mixtures

1992

We calculate the mean-square end-to-end distances and mean-square gyration radii using the bond fluctuation model for a binary polymer blend in the presence of a wall by Monte Carlo simulation. In the bulk, the size of the minority, low-concentration polymer species is compressed compared to the majority one. In the vicinity of the wall, where the minority polymer concentration is enriched due to attraction from the wall, the dimensions of the two types of polymers are approximately equal and are essentially the same as in an athermal polymer melt. Thus, the geometric constraint is more important to the structure of the polymers than the polymer-polymer and polymer-wall interactions.

Branched versus linear polyisoprene: Fractionation and phase behavior

2007

Abstract Branched polyisoprene (PI) was prepared from PI-macromonomers. Linear byproducts of the synthesized polymer were removed by means of inverse spin fractionation, using the solvent cyclohexane (CH) and the precipitant acetone (AC). A well-defined fraction (Mw = 17.5 kg/mol, Mw/Mn = 1.8) of the branched polyisoprene obtained in this manner was used to determine different phase diagrams with branched and/or linear PI in the mixed solvent CH/AC at 25 °C. For comparable molar masses of the polymers the two-phase area is smallest for the branched PI and slightly larger for the linear PI; in the case of the unfractionated original sample of the branched polymer one observes a pronounced pe…

Changing forest stakeholders’ perception of ecosystem services with linguistic nudging

2019

This paper explores whether the perceptions of forest owners and professionals could be nudged towards more sustainable management practices by adjusting a policy text's metaphorical content. Recent research has demonstrated a link between information interventions and preference change, but there is a need to further explore individuals' reactions to information on forest-based ecosystem services and to link these to the design of policy instruments. We contribute to narrowing this gap by nudging the content of a policy text comparing rotation forest management (RFM) and continuous cover forestry (CCF), and exposing it to forest stakeholders. The research is carried out in Finland, the so-…

Abitare in estensione

2014

Il saggio “Abitare in estensione” costituisce un’articolata premessa ai diversi contributi presenti nel volume esito delle attività dell’Unità di ricerca della Facoltà di Architettura di Palermo del Prin 2009 dal titolo Dalla campagna urbanizzata alla “città in estensione”: le norme compositive dell’architettura del territorio dei centri minori (Coordinatore nazionale Prof. Lugi Ramazzotti, responsabile dell’UDR locale Prof. Andrea Sciascia). Dalla stesura del modello B alla pubblicazione finale del Prin trascorrono in media tre anni. Anzi, qualche mese in meno, in considerazione dei tempi sempre più brevi imposti dalle nuove norme che regolano la rendicontazione finale. Durante questo peri…

A tale of two palaces and a city: Valencia, 1238-1460

2013

Este artículo estudia las relaciones entre el palacio del Real (Palau del Real), la residencia de los reyes de Aragón en Valencia y la Casa de la Ciudad (Casa de la Ciutat o Sala del Consell) desde la conquista cristiana hasta el final del reinado de Alfonso V el Magnánimo. Durante dos siglos la corte real y el gobierno de la ciudad manifestaron la alianza, la rivalidad y los conflictos a través de la arquitectura y la decoración de sus respectivas sedes. Los emplazamientos, las grandes salas, las capillas con reliquias y las fiestas cívicas desempeñaron un papel notable como instrumentos al servicio tanto de los reyes y sus oficiales como de los consejeros municipales. Aunque ambos palacio…

Dynamic aspects of industrial middleware architectures

2011

A gearbox model for processing large volumes of data by using pipeline systems encapsulated into virtual containers

2020

Software pipelines enable organizations to chain applications for adding value to contents (e.g., confidentially, reliability, and integrity) before either sharing them with partners or sending them to the cloud. However, the pipeline components add overhead when processing large volumes of data, which can become critical in real-world scenarios. This paper presents a gearbox model for processing large volumes of data by using pipeline systems encapsulated into virtual containers. In this model, the gears represent applications, whereas gearboxes represent software pipelines. This model was implemented as a collaborative system that automatically performs Gear up (by using parallel patterns…