4,001 research outputs found
Emotions and identity work: Emotions as discursive resources in the constitution of junior professionals’ identities
© The Author(s) 2018. For junior professionals, notions of professional identity established during their education are often called into question in the early stages of their professional careers. The workplace gives rise to identity challenges that manifest in significant emotional struggles. However, although extant literature highlights how emotions trigger and accompany identity work, the constitutive role of emotions in identity work is under-researched. In this article, we analyse how junior professionals mobilize emotions as discursive resources for identity work. Drawing on an empirical study of junior architects employed in professional service firms, we examine how professional identities, imbued with varying forms of discipline and agency, are discursively represented. The study makes two contributions to the literature on emotions and identity work. First, we identify three key identity work strategies (idealizing, reframing and distancing) that are bound up in junior architects’ emotion talk. We suggest that these strategies act simultaneously as a coping mechanism and as a disciplinary force in junior architects’ efforts to constitute themselves as professionals. Second, we argue that identity work may not always lead to the accomplishment of a positive sense of self but can express a sense of disillusionment that leads to the constitution of dejected professional identities
Practical Forecasting of AC Losses in Multi-layer 2G-HTS Cold Dielectric Conductors
With the recent progresses on the designing and manufacturing of lightweight
and high engineering current density superconducting cables, the need for an
established, fast, and sufficiently accurate computational model for the
forecasting of AC-losses in cold-dielectric conductors, is pivotal for
increasing the investment confidence of power grid operators. However,
validating such models is not an easy task, this because on the one hand, there
is a low availability of experimental results for large scale power cables and,
on the other hand, there is a large number of 2G-HTS tapes involved whose
cross-sectional aspect ratio hinders the numerical convergence of the models
within reasonable delivery times. Thus, aiming to overcome this challenge, we
present a detailed two-dimensional H-model capable to reproduce the
experimentally measured AC-losses of multi-layer power cables made of tens of
2G-HTS tapes. Two cable designs with very high critical currents have been
considered, the first rated at 1.7 kA critical current, consisting of fifty 4
mm width 2G-HTS tapes, these split in 5 concentric layers wound over a
cylindrical former, with the three inner layers forming an arrangement of 24
tapes shielded by two further layers with 13 tapes each. This cable is
contrasted with a size wise equivalent cable with 67 superconducting tapes
rated at 3.2 kA critical current, whose design implies the use of 40 tapes of 3
mm width split within four core layers, and 27 tapes of 4 mm width distributed
in two shielding layers. In both situations a remarkable resemblance between
the simulations and experiments has been found, rendering to acceptable
estimates of the AC-losses for cold dielectric conductors, and offering a
unique view of the local electrodynamics of the wound tapes where the
mechanisms of shielding, magnetization, and transport currents can coexist
within the hysteretic process.Comment: 4 Figures, 6 page
Demixing, remixing and cellular networks in binary liquids containing colloidal particles
We present a confocal-microscopy study of demixing and remixing in binary
liquids containing colloidal particles. First, particle-stabilized emulsions
have been fabricated by nucleation and growth of droplets upon cooling from the
single-fluid phase. We show that their stability mainly derives from
interfacial particles; the surplus of colloids in the continuous phase possibly
provides additional stability. Upon heating these emulsions, we have observed
the formation of polyhedral cellular networks of colloids, just before the
system remixes. Given a suitable liquid-liquid composition, the initial
emulsions cross the binary-liquid symmetry line due to creaming. Therefore,
upon heating, the droplets do not shrink and they remain closely packed. The
subsequent network formation relies on a delicate balance between the Laplace
pressure and the pressure due to creaming/remixing. As high concentrations of
colloids in the cell walls inhibit film thinning and rupture, the networks can
be stabilized for more than 30 minutes. This opens up an avenue for their
application in the fabrication of advanced materials.Comment: http://dx.doi.org/10.1039/b918002
High-resolution x-ray study of the nematic - smectic-A and smectic-A - smectic-C transitions in 8barS5-aerosil gels
The effects of dispersed aerosil nanoparticles on two of the phase
transitions of the thermotropic liquid crystal material
4-n-pentylphenylthiol-4'-n-octyloxybenzoate 8barS5 have been studied using
high-resolution x-ray diffraction techniques. The aerosils hydrogen bond
together to form a gel which imposes a weak quenched disorder on the liquid
crystal. The smectic-A fluctuations are well characterized by a two-component
line shape representing thermal and random-field contributions. An elaboration
on this line shape is required to describe the fluctuations in the smectic-C
phase; specifically the effect of the tilt on the wave-vector dependence of the
thermal fluctuations must be explicitly taken into account. Both the magnitude
and the temperature dependence of the smectic-C tilt order parameter are
observed to be unaffected by the disorder. This may be a consequence of the
large bare smectic correlation length in the direction of modulation for this
transition. These results show that the understanding developed for the nematic
to smectic-A transition for octylcyanobiphenyl (8CB) and octyloxycyanobiphenyl
(8OCB) liquid crystals with quenched disorder can be extended to quite
different materials and transitions.Comment: 7 pages, 8 figure
Accurate Measurements of Aerosol Hygroscopic Growth over a Wide Range in Relative Humidity
Using a comparative evaporation kinetics approach, we describe a new and accurate method for determining the equilibrium hygroscopic growth of aerosol droplets. The time-evolving size of an aqueous droplet, as it evaporates to a steady size and composition that is in equilibrium with the gas phase relative humidity, is used to determine the time-dependent mass flux of water, yielding information on the vapor pressure of water above the droplet surface at every instant in time. Accurate characterization of the gas phase relative humidity is provided from a control measurement of the evaporation profile of a droplet of know equilibrium properties, either a pure water droplet or a sodium chloride droplet. In combination, and by comparison with simulations that account for both the heat and mass transport governing the droplet evaporation kinetics, these measurements allow accurate retrieval of the equilibrium properties of the solution droplet (i.e., the variations with water activity in the mass fraction of solute, diameter growth factor, osmotic coefficient or number of water molecules per solute molecule). Hygroscopicity measurements can be made over a wide range in water activity (from >0.99 to, in principle, 0.9 and ∼±1% below 80% RH, and maximum uncertainties in diameter growth factor of ±0.7%. For all of the inorganic systems examined, the time-dependent data are consistent with large values of the mass accommodation (or evaporation) coefficient (>0.1)
A new infrared band in the Interstellar and Circumstellar Clouds: C_4 or C_4H?
We report on the detection with the Infrared Space Observatory (ISO) of a
molecular band at 57.5 microns (174 cm^{-1}) in carbon-rich evolved stars and
in Sgr B2. Taking into account the chemistry of these objects the most
likelihood carrier is a carbon chain. We tentatively assign the band to the
nu_5 bending mode of C_4 for which a wavenumber of 170-172.4 cm^{-1} has been
derived in matrix experiments (Withey et al. 1991). An alternate carrier might
be C_4H, although the frequency of its lowest energy vibrational bending mode,
nu_7, is poorly known (130-226 cm^{-1}). If the carrier is C_4, the derived
maximum abundance is nearly similar to that found for C_3 in the interstellar
and circumstellar media by Cernicharo, Goicoechea & Caux (2000). Hence,
tetra-atomic carbon could be one of the most abundant carbon chain molecules in
these media.Comment: 11 pages, 1 figure, accepted in ApJ Letter
Vita contemplativa: a life in part
Life, art and science are irremediably intertwined: how, where and with whom one shares the brief moments of existence necessarily affect what one thinks, how one writes, and what one will address. Being a scholar is a vocation, as Weber knew only too well, in which science, ethics and art blend; sometimes seamlessly, sometimes not. None who live an intellectual and public life are immune to the normal glosses of the sociology of knowledge and this paper provides glimpses, through a personal lens, of what such a gloss might see. It is a glimpse of a life still living and lived; an artist still at work, an agenda still being developed, frozen like a snapshot of an instant - and just as representative. Can a snapshot capture an essence? Sometimes. Whether this does is left to others to judge. Copyright © 2005 SAGE Publications
3D Modelling and Validation of the Optimal Pitch in Commercial CORC Cables
Conductor on a rounded core (CORC\textsuperscript{\textregistered}) cables
with current densities beyond 300 A/mm at 4.2 K, and a capacity to
retain around 90 of critical current after bending to a diameter of 3.5
cm, make them a strong candidate for high field power applications and magnets.
In this paper, we present a full 3D-FEM model based upon the so-called
H-formulation for commercial CORC\textsuperscript{\textregistered} cables
manufactured by Advanced Conductor Technologies LLC. The model presented
consists of tapes ranging from 1 up to 3 SuperPower 4mm-width tapes in 1 single
layer and at multiple pitch angles. By varying the twist pitch, local
electromagnetic characteristics such as the current density distribution along
the length and width are visualized. Measurements of macroscopical quantities
such as AC-losses are disclosed in comparison with available experimental
measurements. We particularly focused on the influence of the twist pitch by
comparing the efficiency and performance of multiple cables, critically
assessing the optimal twist pitch angle.Comment: 9 pages, 3 figures, CEC/ICMC'21 Conference, IOP Conference Series:
Materials Science and Engineering, Advances in Cryogenic Engineerin
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