566 research outputs found
Influence of strain on magnetization and magnetoelectric effect in La0.7A0.3MnO3 / PMN-PT(001) (A = Sr; Ca)
We investigate the influence of a well-defined reversible biaxial strain
<=0.12 % on the magnetization (M) of epitaxial ferromagnetic manganite films. M
has been recorded depending on temperature, strain and magnetic field in 20 -
50 nm thick films. This is accomplished by reversibly compressing the isotropic
in-plane lattice parameter of the rhombohedral piezoelectric 0.72PMN-0.28PT
(001) substrates by application of an electric field E <= 12 kV cm-1. The
magnitude of the total variable in-plane strain has been derived.
Strain-induced shifts of the ferromagnetic Curie temperature (Tc) of up to 19 K
were found in La0.7Sr0.3MnO3 (LSMO) and La0.7Ca0.3MnO3 films and are
quantitatively analysed for LSMO within a cubic model. The observed large
magnetoelectric coupling coefficient alpha=mu0 dM/dE <= 6 10-8 s m-1 at ambient
temperature results from the strain-induced M change in the
magnetic-film-ferroelectric-substrate system. It corresponds to an enhancement
of mu0 DeltaM <= 19 mT upon biaxial compression of 0.1 %. The extraordinary
large alpha originates from the combination of three crucial properties: (i)
the strong strain dependence of M in the ferromagnetic manganites, (ii) large
piezo-strain of the PMN-PT substrates and (iii) effective elastic coupling at
the film-substrate interface.Comment: 15 pages, 6 figures, 1 tabl
Rapid sea ice changes in the future Barents Sea
Observed and future winter Arctic sea ice loss is strongest in the Barents Sea.
However, the anthropogenic signal of the sea ice decline is superimposed by pronounced internal variability that represents a large source of uncertainty in future climate projections.
A notable manifestation of internal variability is rapid ice change events (RICEs) that greatly exceed the anthropogenic trend.
These RICEs are associated with large displacements of the sea ice edge which could potentially have both local and remote impacts on the climate system.
In this study we present the first investigation of the frequency and drivers of RICEs in the future Barents Sea, using multi-member ensemble simulations from CMIP5 and CMIP6.
A majority of RICEs are triggered by trends in ocean heat transport or surface heat fluxes.
Ice loss events are associated with increasing trends in ocean heat transport and decreasing trends in surface heat loss.
RICEs are a common feature of the future Barents Sea until the region becomes close to ice-free.
As their evolution over time is closely tied to the average sea ice conditions, rapid ice changes in the Barents Sea may serve as a precursor for future changes in adjacent seas.</p
High prevalence of vitamin D insufficiency in professional handball athletes
OBJECTIVES: Vitamin D affects multiple body functions through the regulation of gene expression. In sports medicine, its influence on musculoskeletal health and performance is of particular interest. Vitamin D insufficiency might decrease athletic performance and increase the risk of musculoskeletal injuries. Several studies have demonstrated vitamin D deficiency in professional athletes; however, the prevalence of vitamin D insufficiency in professional handball players is yet unknown.
METHODS: The study was planned as a prospective, non-interventional study. We examined 70 male elite handball athletes (first league) in a pre-competition medical assessment in July. Age, height, weight, body mass index, 25-OH vitamin D, calcium, and parathyroid hormone were evaluated, and a sun exposure score was calculated. Players were then divided into two groups of vitamin D levels: insufficient (<30 ng/mL) and sufficient (≥30 ng/mL).
RESULTS: The mean 25-OH vitamin D level of the 70 players was 33.5 ± 10.9 ng/mL (median 32.2, IQR 26.5-38.9 ng/mL). Thirty-nine (55.7%) had sufficient and 31 (44.3%) insufficient levels. Athletes with sufficient vitamin D levels had significantly lower parathyroid hormone levels than athletes with insufficiency (24.9 ± 12.1 vs. 33.5 ± 15.1 ng/mL, p = 0.02). All other parameters evaluated demonstrated no significant difference between the two groups.
CONCLUSION: Vitamin D insufficiency is a common finding in professional handball athletes even in summer, which might negatively affect physical performance. Furthermore, it might lead to an increased risk of musculoskeletal injuries and infections. This should be evaluated in further studies
Monitoring of tritium purity during long-term circulation in the KATRIN test experiment LOOPINO using laser Raman spectroscopy
The gas circulation loop LOOPINO has been set up and commissioned at Tritium
Laboratory Karlsruhe (TLK) to perform Raman measurements of circulating tritium
mixtures under conditions similar to the inner loop system of the neutrino-mass
experiment KATRIN, which is currently under construction. A custom-made
interface is used to connect the tritium containing measurement cell, located
inside a glove box, with the Raman setup standing on the outside. A tritium
sample (purity > 95%, 20 kPa total pressure) was circulated in LOOPINO for more
than three weeks with a total throughput of 770 g of tritium. Compositional
changes in the sample and the formation of tritiated and deuterated methanes
CT_(4-n)X_n (X=H,D; n=0,1) were observed. Both effects are caused by hydrogen
isotope exchange reactions and gas-wall interactions, due to tritium {\beta}
decay. A precision of 0.1% was achieved for the monitoring of the T_2
Q_1-branch, which fulfills the requirements for the KATRIN experiment and
demonstrates the feasibility of high-precision Raman measurements with tritium
inside a glove box
Produção de base ecológica e agroecologia na percepção de estudantes de Ciências Agrárias da Universidade Federal de Santa Maria (UFSM)
O artigo analisa as percepções de estudantes de graduação do Centro de Ciências Rurais da Universidade Federal de Santa Maria (UFSM) referentes á Agroecologia e técnicas de produção sustentável. Pressupondo que Agroecologia e técnicas correlatas fazem parte de complexo sistema de estudos e práticas, em um novo paradigma cientÃfico e produtivo, não há consenso quanto aos conteúdos. Para verificar o nÃvel de entendimento dos temas por parte de estudantes de ensino superior, foi realizado um questionário com amostra da população universitária da UFSM, tratando questões particulares, de entendimento dos temas, e da abordagem em aula. Observa-se alto nÃvel de interesse para com as temáticas.
Entretanto, os dados mostram dúvidas em relação aos conteúdos e insatisfação quanto ao modo e frequência como são tratados em aula. O fator ambiental predominou no entendimento do paradigma e a Agroecologia é abordada como conjunto de práticas, não sendo considerada, pela maioria, como ciência.The article analyzes the perceptions of Rural Sciences Center undergraduate students, of the Federal University of Santa Maria (UFSM), regarding Agroecology and sustainable production techniques. Assuming Agroecology and related technics as part of complex studies and a practical system in a new scientific and productive paradigm, no consensus was found in contents. To check the understanding level of the issues by undergraduate students, it was done a questionnaire applied to a sample of the UFSM university population addressing personal, understanding of the issues, and approach in class questions. It is observed high level of interest related to the main issue. However, the data showed doubts about the content and no satisfaction regarding the manner and frequency these subjects are handled in class. The environmental aspect prevailed regarding to the paradigm’s understanding and, Agroecology was addressed as practices set, it was not considered for most a science.Eje A5: Sistemas de conocimientoFacultad de Ciencias Agrarias y Forestale
Produção de base ecológica e agroecologia na percepção de estudantes de Ciências Agrárias da Universidade Federal de Santa Maria (UFSM)
O artigo analisa as percepções de estudantes de graduação do Centro de Ciências Rurais da Universidade Federal de Santa Maria (UFSM) referentes á Agroecologia e técnicas de produção sustentável. Pressupondo que Agroecologia e técnicas correlatas fazem parte de complexo sistema de estudos e práticas, em um novo paradigma cientÃfico e produtivo, não há consenso quanto aos conteúdos. Para verificar o nÃvel de entendimento dos temas por parte de estudantes de ensino superior, foi realizado um questionário com amostra da população universitária da UFSM, tratando questões particulares, de entendimento dos temas, e da abordagem em aula. Observa-se alto nÃvel de interesse para com as temáticas.
Entretanto, os dados mostram dúvidas em relação aos conteúdos e insatisfação quanto ao modo e frequência como são tratados em aula. O fator ambiental predominou no entendimento do paradigma e a Agroecologia é abordada como conjunto de práticas, não sendo considerada, pela maioria, como ciência.The article analyzes the perceptions of Rural Sciences Center undergraduate students, of the Federal University of Santa Maria (UFSM), regarding Agroecology and sustainable production techniques. Assuming Agroecology and related technics as part of complex studies and a practical system in a new scientific and productive paradigm, no consensus was found in contents. To check the understanding level of the issues by undergraduate students, it was done a questionnaire applied to a sample of the UFSM university population addressing personal, understanding of the issues, and approach in class questions. It is observed high level of interest related to the main issue. However, the data showed doubts about the content and no satisfaction regarding the manner and frequency these subjects are handled in class. The environmental aspect prevailed regarding to the paradigm’s understanding and, Agroecology was addressed as practices set, it was not considered for most a science.Eje A5: Sistemas de conocimientoFacultad de Ciencias Agrarias y Forestale
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