143 research outputs found
Relationship initiation and formation in post-match Tinder chat conversations
This article uses conversation analysis to investigate the communicative practices of unacquainted, matched Tinder users in chat conversations, in the process of developing a potential romantic relationship. Drawing on data from 157 Tinder conversations, the analysis explores the occasioning of talk about personal and intimate matters. The analysis shows that the interactional device through which the revelation of personal and intimate information is prompted is the ‘elicited self-disclosure sequence’. In cases in which a direct question fails to prompt a disclosure from the recipient, the ‘volunteered self-disclosure sequence’ emerges as an alternative to promote the revelation of further intimate information. We conclude by observing that relationships are ongoing routine accomplishments arising in mundane sociorelational contexts. The data are in Spanish and Catalan with English translations
Intermittent-Contact Heterodyne Force Microscopy
Heterodyne Force Microscopy opens up a way to monitor nanoscale events with high temporal sensitivity from the quasistatic cantilever mechanical-diode response taking advantage of the beat effect. Here, a novel heterodyne ultrasonic force method is proposed, in which the cantilever is driven in amplitude-modulation mode, at its fundamental flexural eigenmode. Ultrasonic vibration in the megahertz range is additionally input at the tip-sample contact from the cantilever base and from the back of the sample. The ultrasonic frequencies are chosen in such a way that their difference is coincident with the second cantilever eigenmode. In the presence of ultrasound, cantilever vibration at the difference frequency is detected. Similarly as in heterodyne force microscopy, it is expected that the phase response yields information with increased sensitivity due to the beat effect
Ultrasonic force microscopy on 'poly(vinyl alcohol)/SrTiO3' nano-perovskites hybrid films
Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) have been
applied to the characterization of composite samples formed by SrTiO 3 (STO)
nanoparticles (NPs) and polyvinyl alcohol (PVA). The morphological features of
the STO NPs were much better resolved in UFM than in contact-mode AFM
topography. For high STO concentrations the individual STO NPs formed
nanoclusters, which gathered in microaggregates. The STO aggregates, covered by
PVA, exhibited no AFM frictional contrast, but were clearly distinguished from
the PVA matrix using UFM. Similar aggregation was observed for NPs in the
composite samples than for NPs deposited on top of a flat silicon substrate
from a milliQ water solution in the absence of polymer. In the hybrid films,
most STO nanoparticles typically presented a lower UFM contrast than the PVA
matrix, even though stiffer sample regions such as STO should give rise to a
higher UFM contrast. STO NPs with intermediate contrast were characterized by
an UFM halo of lower contrast at the PVA/STO interface. The results may be
explained by considering that ultrasound is effectively damped on the nanometer
scale at PVA/ STO interfaces. According to our data, the nanoscale ultrasonic
response at the PVA/STO interface plays a fundamental role in the UFM image
contrast
Nanoscale Visualization of Elastic Inhomogeneities at TiN Coatings Using Ultrasonic Force Microscopy
Ultrasonic force microscopy has been applied to the characterization of titanium nitride coatings deposited by physical vapor deposition dc magnetron sputtering on stainless steel substrates. The titanium nitride layers exhibit a rich variety of elastic contrast in the ultrasonic force microscopy images. Nanoscale inhomogeneities in stiffness on the titanium nitride films have been attributed to softer substoichiometric titanium nitride species and/or trapped subsurface gas. The results show that increasing the sputtering power at the Ti cathode increases the elastic homogeneity of the titanium nitride layers on the nanometer scale. Ultrasonic force microscopy elastic mapping on titanium nitride layers demonstrates the capability of the technique to provide information of high value for the engineering of improved coatings
The intensity contrast of solar granulation: comparing Hinode SP results with MHD simulations
The contrast of granulation is an important quantity characterizing solar
surface convection. We compare the intensity contrast at 630 nm, observed using
the Spectro-Polarimeter (SP) aboard the Hinode satellite, with the 3D radiative
MHD simulations of V{\"o}gler & Sch{\"u}ssler (2007). A synthetic image from
the simulation is degraded using a theoretical point-spread function of the
optical system, and by considering other important effects. The telescope
aperture and the obscuration by the secondary mirror and its attachment spider,
reduce the simulated contrast from 14.4 % to 8.5 %. A slight effective defocus
of the instrument brings the simulated contrast down to 7.5 %, close to the
observed value of 7.0 %. A proper consideration of the effects of the optical
system and a slight defocus, lead to sufficient degradation of the synthetic
image from the MHD simulation, such that the contrast reaches almost the
observed value. The remaining small discrepancy can be ascribed to straylight
and slight imperfections of the instrument, which are difficult to model.
Hence, Hinode SP data are consistent with a granulation contrast which is
predicted by 3D radiation MHD simulations.Comment: 5 pages, 4 figures, to be published in A&
Photometric properties of resolved and unresolved magnetic elements
We investigate the photometric signature of magnetic flux tubes in the solar
photosphere. We developed two dimensional, static numerical models of isolated
and clustered magnetic flux tubes. We investigated the emergent intensity
profiles at different lines-of-sight for various spatial resolutions and
opacity models. We found that both geometric and photometric properties of
bright magnetic features are determined not only by the physical properties of
the tube and its surroundings, but also by the particularities of the
observations, including the line/continuum formation height, the spatial
resolution and the image analyses techniques applied. We show that some
observational results presented in the literature can be interpreted by
considering bright magnetic features to be clusters of smaller elements, rather
than a monolithic flux tube.Comment: 12 page
Interaction imaging with amplitude-dependence force spectroscopy
Knowledge of surface forces is the key to understanding a large number of
processes in fields ranging from physics to material science and biology. The
most common method to study surfaces is dynamic atomic force microscopy (AFM).
Dynamic AFM has been enormously successful in imaging surface topography, even
to atomic resolution, but the force between the AFM tip and the surface remains
unknown during imaging. Here, we present a new approach that combines high
accuracy force measurements and high resolution scanning. The method, called
amplitude-dependence force spectroscopy (ADFS) is based on the
amplitude-dependence of the cantilever's response near resonance and allows for
separate determination of both conservative and dissipative tip-surface
interactions. We use ADFS to quantitatively study and map the nano-mechanical
interaction between the AFM tip and heterogeneous polymer surfaces. ADFS is
compatible with commercial atomic force microscopes and we anticipate its
wide-spread use in taking AFM toward quantitative microscopy
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