153 research outputs found
Conveying personality traits trough product design for a symbolic product
Product design, through its sensory attributes, plays a major role in product perceptions and its understanding by consumers. It conveys rich symbolic associations and contributes to shape brand image and its personality traits. A flower is a singular product, expressive and particularly evocative through its design. We postulate that flowers can be considered as brands possessing human-like traits. An experiment being run on two flowers\u27 varieties (tulips and roses) with 509 French participants shows how shape (pointed or rounded petals) and brightness (pink for the light color or purple for the dark color) influence the perceived flower\u27s personality, with gender as a moderating variable. The findings confirm the power of design to shape consumers\u27 perceptions, especially for symbolic products such as flowers
Numerical study of an arcan tensile compression shear test in dynamic: application to bonded joints
This paper presents a numerical study of the Arcan TCS testing device under dynamic conditions. This test is commonly used to characterize the mechanical behavior of bonded joints subjected to combined quasi-static loadings. In this study, the question of its extensibility to dynamic loadings by the use of an impactor guided in a drop tower is investigated. A dedicated finite element model is built under the plane stress assumption. Stress distributions in the adhesive are analysed trought time ans space for several configurations
Hot-Carrier Cooling in High-Quality Graphene is Intrinsically Limited by Optical Phonons
Many promising optoelectronic devices, such as broadband photodetectors,
nonlinear frequency converters, and building blocks for data communication
systems, exploit photoexcited charge carriers in graphene. For these systems,
it is essential to understand, and eventually control, the cooling dynamics of
the photoinduced hot-carrier distribution. There is, however, still an active
debate on the different mechanisms that contribute to hot-carrier cooling. In
particular, the intrinsic cooling mechanism that ultimately limits the cooling
dynamics remains an open question. Here, we address this question by studying
two technologically relevant systems, consisting of high-quality graphene with
a mobility >10,000 cmVs and environments that do not
efficiently take up electronic heat from graphene: WSe-encapsulated
graphene and suspended graphene. We study the cooling dynamics of these two
high-quality graphene systems using ultrafast pump-probe spectroscopy at room
temperature. Cooling via disorder-assisted acoustic phonon scattering and
out-of-plane heat transfer to the environment is relatively inefficient in
these systems, predicting a cooling time of tens of picoseconds. However, we
observe much faster cooling, on a timescale of a few picoseconds. We attribute
this to an intrinsic cooling mechanism, where carriers in the hot-carrier
distribution with enough kinetic energy emit optical phonons. During phonon
emission, the electronic system continuously re-thermalizes, re-creating
carriers with enough energy to emit optical phonons. We develop an analytical
model that explains the observed dynamics, where cooling is eventually limited
by optical-to-acoustic phonon coupling. These fundamental insights into the
intrinsic cooling mechanism of hot carriers in graphene will play a key role in
guiding the development of graphene-based optoelectronic devices
Position and momentum mapping of vibrations in graphene nanostructures in the electron microscope
Propagating atomic vibrational waves, phonons, rule important thermal,
mechanical, optoelectronic and transport characteristics of materials. Thus the
knowledge of phonon dispersion, namely the dependence of vibrational energy on
momentum is a key ingredient to understand and optimize the material's
behavior. However, despite its scientific importance in the last decade, the
phonon dispersion of a freestanding monolayer of two dimensional (2D) materials
such as graphene and its local variations has still remained elusive because of
experimental limitations of vibrational spectroscopy. Even though electron
energy loss spectroscopy (EELS) in transmission has recently been shown to
probe the local vibrational charge responses, these studies are yet limited to
polar materials like boron nitride or oxides, in which huge signals induced by
strong dipole moments are present. On the other hand, measurements on graphene
performed by inelastic x-ray (neutron) scattering spectroscopy or EELS in
reflection do not have any spatial resolution and require large microcrystals.
Here we provide a new pathway to determine the phonon dispersions down to the
scale of an individual freestanding graphene monolayer by mapping the distinct
vibration modes for a large momentum transfer. The measured scattering
intensities are accurately reproduced and interpreted with density functional
perturbation theory (DFPT). Additionally, a nanometre-scale mapping of selected
momentum (q) resolved vibration modes using graphene nanoribbon structures has
enabled us to spatially disentangle bulk, edge and surface vibrations
Understanding Novel Superconductors with Ab Initio Calculations
This chapter gives an overview of the progress in the field of computational
superconductivity.
Following the MgB2 discovery (2001), there has been an impressive
acceleration in the development of methods based on Density Functional Theory
to compute the critical temperature and other physical properties of actual
superconductors from first-principles. State-of-the-art ab-initio methods have
reached predictive accuracy for conventional (phonon-mediated) superconductors,
and substantial progress is being made also for unconventional superconductors.
The aim of this chapter is to give an overview of the existing computational
methods for superconductivity, and present selected examples of material
discoveries that exemplify the main advancements.Comment: 38 pages, 10 figures, Contribution to Springer Handbook of Materials
Modellin
Modeling and experiment of the suspended seismometer concept for attenuating the contribution of tilt motion in horizontal measurements
In vitro shoot induction and multiplication from nodal segments of adult Ginkgo biloba plants
Reassessing the effect of colour on attitude and behavioural intentions in promotional activities: The moderating role of mood and involvement
The present research examines the effect of background colour on attitude and behavioural intentions in various promotional activities taking into consideration the moderating role of mood and involvement. Three experiments reflecting different promotional activities (window display, consumer trade show, guerrilla marketing) were conducted for this purpose. Overall, findings indicate that cool background colours, in contrast to warm colours, induce more positive attitudes and behavioural intentions mainly in positive mood, and low involvement conditions. Implications are also discussed
- …