Abstract
The functional properties of cuprates are strongly determined by the doping state and carrier density. We present an oxygen doping study of YBa
2
Cu
3
O
7-δ
(YBCO) thin films from underdoped ...to overdoped state, correlating the measured charge carrier density,
$${n}_{\mathrm{H}}$$
n
H
, the hole doping,
p
, and the critical current density,
$${J}_{c}$$
J
c
. Our results show experimental demonstration of strong increase of
$${J}_{c}$$
J
c
with
$${n}_{\mathrm{H}}$$
n
H
, up to Quantum Critical Point (QCP), due to an increase of the superconducting condensation energy. The ultra-high
$${J}_{c}$$
J
c
achieved, 90 MA cm
−2
at 5 K corresponds to about a fifth of the depairing current, i.e. a value among the highest ever reported in YBCO films. The overdoped regime is confirmed by a sudden increase of
$${n}_{\mathrm{H}}$$
n
H
, associated to the reconstruction of the Fermi-surface at the QCP. Overdoping YBCO opens a promising route to extend the current carrying capabilities of rare-earth barium copper oxide (REBCO) coated conductors for applications.
Phosphorus is a crucial element for the development of life, but so far P-bearing molecules have been detected only in a few astrophysical objects; hence, its interstellar chemistry is almost totally ...unknown. Here, we show new detections of phosphorus nitride (PN) in a sample of dense cores in different evolutionary stages of the intermediate- and high-mass star formation process: starless, with protostellar objects, and with ultracompact H II regions. All detected PN line widths are smaller than Asymptotically = to 5 km s super(-1), and they arise from regions associated with kinetic temperatures smaller than 100 K. Because the few previous detections reported in the literature are associated with warmer and more turbulent sources, the results of this work show that PN can arise from relatively quiescent and cold gas. This information is challenging for theoretical models that invoke either high desorption temperatures or grain sputtering from shocks to release phosphorus into the gas phase. Derived column densities are of the order of 10 super(11-12) cm super(-2), marginally lower than the values derived in the few high-mass star-forming regions detected so far. New constraints on the abundance of phosphorus monoxide, the fundamental unit of biologically relevant molecules, are also given.
This paper assesses annual and seasonal trends in runoff and sediment load resulting from climate variability and afforestation in an upland Mediterranean basin, the Ribera Salada (NE Iberian ...Peninsula). We implemented a hydrological and sediment transport distributed model (TETIS) with a daily time-step, using continuous discharge and sediment transport data collected at a monitoring station during the period 2009–2013. Once calibrated and validated, the model was used to simulate the hydrosedimentary response of the basin for the period 1971–2014 using historical climate and land use data. Simulated series were further used to (i) detect sediment transport and hydrologic trends at different temporal scales (annual, seasonal); (ii) assess changes in the contribution of extreme events (i.e. low and high flows) and (ii) assess the relative effect of forest expansion and climate variability on trends observed by applying a scenario of constant land use. The non-parametric Mann–Kendall test indicated upward trends for temperature and decreasing trends (although non-significant) for precipitation. Downward trends occurred for annual runoff, and less significantly for sediment yield. Reductions in runoff were less intense when afforestation was not considered in the model, while trends in sediment yield were reversed. Results also indicated that an increase in the river's torrential behaviour may have occurred throughout the studied period, with low and high flow events gaining importance with respect to the annual contribution, although its magnitude was reduced over time.
Display omitted
•We applied a distributed hydrological model to reconstruct runoff and sediment yield.•Decreasing trends were detected for both variables at the annual and seasonal time scales.•Afforestation seemed to be the main factor driving the trends observed.•An increase in the torrential behaviour and reduction of peak flows was detected.
Context. Theory predicts, and observations confirm, that the column density ratio of a molecule containing D to its counterpart containing H can be used as an evolutionary tracer in the low-mass star ...formation process. Aims. Since it remains unclear if the high-mass star formation process is a scaled-up version of the low-mass one, we investigated whether the relation between deuteration and evolution can be applied to the high-mass regime. Methods. With the IRAM-30 m telescope, we observed rotational transitions of N2D+ and N2H+ and derived the deuterated fraction in 27 cores within massive star-forming regions understood to represent different evolutionary stages of the massive-star formation process. Results. The abundance of N2D+ is higher at the pre-stellar/cluster stage, then drops during the formation of the protostellar object(s) as in the low-mass regime, remaining relatively constant during the ultra-compact HII region phase. The objects with the highest fractional abundance of N2D+ are starless cores with properties very similar to typical pre-stellar cores of lower mass. The abundance of N2D+ is lower in objects with higher gas temperatures as in the low-mass case but does not seem to depend on gas turbulence. Conclusions. Our results indicate that the N2D+-to-N2H+ column density ratio can be used as an evolutionary indicator in both low- and high-mass star formation, and that the physical conditions influencing the abundance of deuterated species likely evolve similarly during the processes that lead to the formation of both low- and high-mass stars.
Introduction
Bipolar disorder, especially Bipolar II subtype, is a mental disorder that has one of the greatest risk of completed suicide (CS).
Objectives
Determine the rate and the risk factors of ...CS in a cohort of Bipolar II patients followed after their first hospitalization
Methods
We choose all Bipolar II patients (DSM-IV) who were hospitalized for first time in our Psychiatric unit between 1996 and 2016. We reviewed the charts of first hospitalization and recorded multiple baseline variables. In the follow-up we updated the database recording all patients who CS. We compared the different baseline variables between Bipolar II patients who CS and the rest
Results
Of a total of 59 bipolar II patients 6 (10 %) CS in the mean of 13 years of follow up (rate 120 times higher than General Population). The average age at CS was 45.3 years (range between 33 and 57 years old) so there was a 2 years gap on average between the first psychiatric hospitalization and suicide. CS was characterized by a violent act (5 out of 6 cases, 83 %). When we compared BP II patients who CS with the rest, only history of previous violent suicide attempt was detected as a risk factor significantly associated (P<0.04) with CS.
Conclusions
Bipolar II patients CS early after their first hospitalization and at very high rate (120 times than GP) almost always by violent method. History of previous violent suicide attempt is predictor of completed suicide
Disclosure
No significant relationships.
Introduction
Bipolar disorder is a mental disorder that has one of the greatest risk of completed suicide (CS)
Objectives
Determine the rate and the risk factors of CS in a cohort of Bipolar I ...patients followed after their first hospitalization
Methods
We choose all Bipolar I patients (DSM-IV) who were first time hospitalized in our Psychiatric unit between 1996 and 2016. We reviewed the charts of first hospitalization and recorded multiple baseline variables. In the follow-up we updated the database recording all patients who CS. We compared the different baseline variables between Bipolar patients who CS and the rest.
Results
Of a total of 254 bipolar I patients 9 (3,5%) CS in the mean of 13 years of follow up (rate 40 times higher than General Population). The average age at CS was 41.1 years (range between 26 and 71 years old) so there was a 9 years gap on average between the first psychiatric hospitalization and suicide. CS was characterized by a violent act (8 out of 9 cases, 89 %). When we compared BP patients who CS with the rest, only history of suicide in first-degree relatives was detected as a risk factor significantly associated (P<0.01) with CS. Conversely baseline treatment with anticonvulsants (mainly valproate) was detected as a significantly (P<0.004) protective factor of CS.
Conclusions
1-Bipolar I patients after first hospitalization completed suicide 40 times higher than general population almost always by violent method 2-History of CS in first-degree relatives is predictor of completed suicide
Disclosure
No significant relationships.
Hydropeaked rivers need attention Batalla, R J; Gibbins, C N; Alcázar, J ...
Environmental research letters,
02/2021, Letnik:
16, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Hydropower is considered a renewable form of energy production, but generating electricity from rivers is not always environmentally benign. The global demand for renewables is increasing rapidly as ...fossil fuels are gradually phased out, so rivers will continue to be subjected to the pressures imposed by hydropower for decades to come. Finding ways of operating hydropower plants that limit impacts on downstream river ecosystems is therefore a pressing global concern. Usually, these plants cause marked and rapid fluctuations in flow in downstream river reaches, termed 'hydropeaking'. Hydropeaks result in a variety of ecological changes in the dynamic mountain rivers they typically affect; declines in fish and insect populations are evident, especially in reaches immediately downstream from the plant. While these changes are often acute and readily apparent, the underlying causal mechanisms remain unclear. We argue here that riverbed sediments are a critical but neglected causal link between hydropeaking flow regimes and ecological changes. We outline how a variety of tools from different branches of river science can now be brought together to understand precisely why hydropeaking alters sediment dynamics; these tools provide a mechanistic explanation for changes in bed sedimentary conditions and channel form across multiple scales and, consequently, a better understanding of ecological changes. By allowing us to simulate the effects of flow fluctuations on sediment dynamics and channel form, these tools also allow us to develop ways of releasing water from hydropeaking dams that limit impacts on aquatic habitat and species.
Context. The Kleinmann-Low nebula in Orion (Orion-KL) is the nearest example of a high-mass star-forming environment. Studying the resolved chemical substructures of this complex region provides ...important insight into the chemistry of high-mass star-forming regions (HMSFRs), as it relates to their evolutionary states. Aims. The goal of this work is to resolve the molecular line emission from individual substructures of Orion-KL at high spectral and spatial resolution and to infer the chemical properties of the associated gas. Methods. We present a line survey of Orion-KL obtained from combined Submillimeter Array (SMA) interferometric and IRAM 30 m single-dish observations. Covering a 4 GHz bandwidth in total, this survey contains over 160 emission lines from 20 species (25 isotopologues), including 11 complex organic molecules (COMs). Spectra are extracted from individual substructures and the intensity-integrated distribution map for each species is provided. We then estimate the rotation temperature for each substructure, along with their molecular column densities and abundances. Results. For the first time, we complement 1.3 mm interferometric data with single-dish observations of the Orion-KL region and study small-scale chemical variations in this region. (1) We resolve continuum substructures on ~3′′ angular scale. (2) We identify lines from the low-abundance COMs CH3COCH3 and CH3CH2OH, as well as tentatively detect CH3CHO and long carbon-chain molecules C6H and HC7N. (3) We find that while most COMs are segregated by type, peaking either towards the hotcore (e.g., nitrogen-bearing species) or the compact ridge (e.g., oxygen-bearing species like HCOOCH3 and CH3OCH3), the distributions of others do not follow this segregated structure (e.g., CH3CH2OH, CH3OH, CH3COCH3). (4) We find a second velocity component of HNCO, SO2, 34SO2, and SO lines, which may be associated with a strong shock event in the low-velocity outflow. (5) Temperatures and molecular abundances show large gradients between central condensations and the outflow regions, illustrating a transition between hot molecular core and shock-chemistry dominated regimes. Conclusions. Our observations of spatially resolved abundance variations in Orion-KL provide the nearest reference source for hot molecular core and outflow chemistry, which will be an important example for interpreting the chemistry of more distant HMSFRs.
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