4,090 research outputs found
Preliminary optical design of PANIC, a wide-field infrared camera for CAHA
In this paper, we present the preliminary optical design of PANIC (PAnoramic
Near Infrared camera for Calar Alto), a wide-field infrared imager for the
Calar Alto 2.2 m telescope. The camera optical design is a folded single
optical train that images the sky onto the focal plane with a plate scale of
0.45 arcsec per 18 micron pixel. A mosaic of four Hawaii 2RG of 2k x 2k made by
Teledyne is used as detector and will give a field of view of 31.9 arcmin x
31.9 arcmin. This cryogenic instrument has been optimized for the Y, J, H and K
bands. Special care has been taken in the selection of the standard IR
materials used for the optics in order to maximize the instrument throughput
and to include the z band. The main challenges of this design are: to produce a
well defined internal pupil which allows reducing the thermal background by a
cryogenic pupil stop; the correction of off-axis aberrations due to the large
field available; the correction of chromatic aberration because of the wide
spectral coverage; and the capability of introduction of narrow band filters
(~1%) in the system minimizing the degradation in the filter passband without a
collimated stage in the camera. We show the optomechanical error budget and
compensation strategy that allows our as built design to met the performances
from an optical point of view. Finally, we demonstrate the flexibility of the
design showing the performances of PANIC at the CAHA 3.5m telescope.Comment: This paper has been presented in the SPIE of Astronomical Telescopes
and Instrumentation 2008 in Marseille (France
Hormonal differences in intimate partner violence perpetrators when they cope with acute stress: A pilot study
Background: Only a few studies have paid attention to the ability of perpetrators of intimate partner violence (IPVAW) against women to cope with acute stress, including hormonal pa-rameters. In fact, previous studies assessed how salivary testosterone (Tsal) and cortisol (Csal) changed after coping with an acute emotional stressor (directly related to IPVAW), and they con-cluded that an imbalance between the two hormones might be characteristic of these men. Never-theless, they neglected to examine the role of other hormones, such as salivary oxytocin (OXsal), which also seemed to play an important role in behavioral regulation, and whether this response could be generalized to other types of stress not directly related to IPVAW. Methods: This study aims to assess whether IPVAW perpetrators (n = 19) present differential hormonal (Tsal, Csal, OXsal and their ratios) and psychological state (anxiety, anger, and general affect) responses when coping with an acute cognitive laboratory stressor (a set of neuropsychological tests performed in front of an expert committee) in comparison with non-violent men (n = 16). This quasi-experimental study also assessed whether the psychological state variables drive this different hormonal response. Re-sults: Our results revealed that IPVAW perpetrators had lower Csal and higher Tsal/Csal ratio levels during the post-task period, as well as higher total levels (average) of OXsal than controls. We also found that, only in IPVAW perpetrators, high levels of baseline anxiety and negative affect were related to high rises in Csal during the stress task. Conclusions: These data present a background showing that IPVAW perpetrators and non-violent men cope differently with stress. These findings might help to identify idiosyncratic profiles of IPVAW perpetrators that can then be employed to establish their therapeutic needs. Moreover, we reinforced the importance of combining biological markers with self-reports, thus increasing the reliability of these forensic assessments. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Wetting Properties of Seven Phosphonium Cation-Based Ionic Liquids
This paper studies the wetting properties of seven phosphonium cation-based ionic liquids: trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate [P66614][(iC8)2PO2], trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate [P66614][BEHP], trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl) imide [P66614][NTf2], tributyltetradecylphosphonium dodecylbenzenesulfonate [P44414][DBS], tributylethylphosphonium diethylphosphate [P4442][DEP], trihexyltetradecylphosphonium dicyanamide [P66614][DCA], and trihexyltetradecylphosphonium chloride [P66614][Cl]. The surface tension was analyzed using the Gibbs free energy in a temperature range of 293-353 K, obtaining the expected linear decrease with temperature rise. The contact angle was measured on four different surfaces (AISI 52100 steel, CrN, TiN, and ZrN) and all liquids with high surface tensions interacting with hydrophobic systems displayed high contact angles as expected. The polarity fraction (PF) and the spreading parameter (SP) were estimated to complete and improve the wetting characterization of these ionic liquids, finding TiN-[P66614][BEHP] and TiN-[P66614][(iC8)2PO2] as the most favorable surface-ionic liquid combinations from a wetting point of view
Factorial Invariance of Self-efficacy in Physical Health Care Scale for Men and Women University Students
The present study analyses the psychometric properties of the Selfefficacy in Physical Health Care Scale. The overall sample consisted of 2006 subjects: 902 women and 1104 men, with a mean age of 18.53 years (SD= 1.52) and 18.84 years (SD= 1.55) respectively. The Factorial Psychometric analysis showed that a three-factorial structure (nutrition, physical health and hydration) was viable and adequate for both populations (men and woman) according to the established psychometric requirements when the informers are the students themselves. The results showed that factor structure, factor loadings and intercepts of the instrument could be considered invariant across groups; however, there are differences between groups in favor of men for the means of the nutrition and physical health factors
Formation of calcium sulfate through the aggregation of sub-3 nanometre primary species
The formation pathways of gypsum remain uncertain. Here, using truly in situ and fast time-resolved small-angle X-ray scattering, we quantify the four-stage solution-based nucleation and growth of gypsum (CaSO4 ·2H2O), an important mineral phase on Earth and Mars. The reaction starts through the fast formation of well-defined, primary species of <3 nm in length (stage I), followed in stage II by their arrangement into domains. The variations in volume fractions and electron densities suggest that these fast forming primary species contain Ca-SO4-cores that self-assemble in stage III into large aggregates. Within the aggregates these well-defined primary species start to grow (stage IV), and fully crystalize into gypsum through a structural rearrangement. Our results allow for a quantitative understanding of how natural calcium sulfate deposits may form on Earth and how a terrestrially unstable phase-like bassanite can persist at low-water activities currently dominating the surface of Mars
Incidents control in radiotherapy oncology
Primer pla de l'escut del monarca del s. XVI,
conservat i ubicat a la porta de la UB. Mesura
1,60 x 2,20 metre si Ă©s de pedra sorrenca
Physiological responses of coccolithophores to abrupt exposure of naturally low pH deep seawater
Upwelling is the process by which deep, cold, relatively high-CO2, nutrient-rich seawater rises to the sunlit surface of the ocean. This seasonal process has fueled geoengineering initiatives to fertilize the surface ocean with deep seawater to enhance productivity and thus promote the drawdown of CO2. Coccolithophores, which inhabit many upwelling regions naturally âfertilizedâ by deep seawater, have been investigated in the laboratory in the context of ocean acidification to determine the extent to which nutrients and CO2 impact their physiology, but few data exist in the field except from mesocosms. Here, we used the Porcupine Abyssal Plain (north Atlantic Ocean) Observatory to retrieve seawater from depths with elevated CO2 and nutrients, mimicking geoengineering approaches. We tested the effects of abrupt natural deep seawater fertilization on the physiology and biogeochemistry of two strains of Emiliania huxleyi of known physiology. None of the strains tested underwent cell divisions when incubated in waters obtained from 1,000 m, artificial upwelling using shallower waters may not be a suitable approach for promoting carbon sequestration for some locations and assemblages, and should therefore be investigated on a site-by-site basis
Morphological properties of slender Ca II H fibrils observed by SUNRISE II
We use seeing-free high spatial resolution Ca II H data obtained by the
SUNRISE observatory to determine properties of slender fibrils in the lower
solar chromosphere. In this work we use intensity images taken with the SUFI
instrument in the Ca II H line during the second scientific flight of the
SUNRISE observatory to identify and track elongated bright structures. After
the identification, we analyze theses structures in order to extract their
morphological properties. We identify 598 slender Ca II H fibrils (SCFs) with
an average width of around 180 km, a length between 500 km and 4000 km, an
average lifetime of ~400 s, and an average curvature of 0.002 arcsec^-1. The
maximum lifetime of the SCFs within our time series of 57 minutes is ~2000 s.
We discuss similarities and differences of the SCFs with other small-scale,
chromospheric structures such as spicules of type I and II, or Ca II K fibrils.Comment: Accepted for publication in The Astrophysical Journal Supplement
Serie
Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study
Ultrafast time-resolved
electronic and infrared absorption measurements
have been carried out on a series of RuÂ(II) polypyridyl complexes
in an effort to delineate the dynamics of vibrational relaxation in
this class of charge transfer chromophores. Time-dependent density
functional theory calculations performed on compounds of the form
[RuÂ(CN-Me-bpy)x(bpy)3âx]2+ (x = 1â3 for compounds 1â3, respectively, where CN-Me-bpy is
4,4âČ-dicyano-5,5âČ-dimethyl-2,2âČ-bipyridine and
bpy is 2,2âČ-bipyridine) reveal features in their charge-transfer
absorption envelopes that allow for selective excitation of the RuÂ(II)â(CN-Me-bpy)
moiety, the lowest-energy MLCT state(s) in each compound of the series.
Changes in band shape and amplitude of the time-resolved differential
electronic absorption data are ascribed to vibrational cooling in
the CN-Me-bpy-localized 3MLCT state with a time constant
of 8 ± 3 ps in all three compounds. This conclusion was corroborated
by picosecond time-resolved infrared absorption measurements; sharpening
of the CN stretch in the 3MLCT excited state was observed
with a time constant of 3.0 ± 1.5 ps in all three members of
the series. Electronic absorption data acquired at higher temporal
resolution revealed spectral modulation over the first 2 ps occurring
with a time constant of Ï = 170 ± 50 fs, in compound 1; corresponding effects are significantly attenuated in compound 2 and virtually absent in compound 3. We assign
this feature to intramolecular vibrational redistribution (IVR) within
the 3MLCT state and represents a rare example of this process
being identified from time-resolved electronic absorption data for
this important class of chromophores
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