Search results for "equation"
showing 10 items of 4219 documents
Study of the accretion torque during the 2014 outburst of the X-ray pulsar GRO J1744−28
2017
We present the spectral and timing analysis of the X-ray pulsar GRO J1744-28 during its 2014 outburst using data collected with the X-ray satellites Swift, INTEGRAL, Chandra, and XMM-Newton. We derived, by phase-connected timing analysis of the observed pulses, an updated set of the source ephemeris. We were also able to investigate the spin-up of the X-ray pulsar as a consequence of the accretion torque during the outburst. Relating the spin-up rate and the mass accretion rate as $\dot{\nu}\propto\dot{M}^{\beta}$, we fitted the pulse phase delays obtaining a value of $\beta=0.96(3)$. Combining the results from the source spin-up frequency derivative and the flux estimation, we constrained …
Speciation Studies of Bifunctional 3-Hydroxy-4-Pyridinone Ligands in the Presence of Zn2+ at Different Ionic Strengths and Temperatures
2019
The acid&ndash
Sport commitment and adherence: A social-cognitive analysis. (Compromiso deportivo y adherencia: Un análisis cognitivo social).
2011
Abstract Statement of problem: This study aimed to analyse the ability of a model based on achievement motivation and self-determination theories to predict adherence to competitive sport. This model incorporated commitment as predictor of adherence. A prospective study was performed with a sample of 302 handball players aged between 14 and 18 years. Structural equation modelling gave support to the model proposed. It was verified the sequence of relationships between perceptions of coach-created mastery climate, psychological needs, self-determined motivation, commitment, and adherence. The major contribution of the study was to confirm a motivational model of adherence based on social-cog…
Steady‐state solutions of the aerotaxis problem
2022
We study the steady-state system of aerotaxis equations in higher dimensions.It is shown that the existence and multiplicity of solutions depend on the totalmass of the colony of bacteria, the energy function, and the boundary conditions.
Climate and agriculture: empirical evidence for countries and agroecological zones of the Sahel
2022
International audience; ow heterogenous is the impact of climate change across space and the type of agricultural production? In this paper, we investigate the relationship between climate change and variability, measured by temperature and rainfall, and agricultural production at the country and agroecological zone levels of the Sahel. We consider a crop production index and five cereals (maize, millet, sorghum, wheat and rice). Based on an original climate database and an agricultural production function estimated for the period 1961–2016, we show that average rainfall and temperature during the growing season indeed have highly heterogeneous effects on agricultural production, depending …
Temperamentally inhibited children are at risk for poorer maths performance : self-concept as mediator
2020
AbstractIt has repeatedly been found that temperamental inhibition and low academic achievement are associated with each other: children with cautious and wary or shy behaviour are at risk for low academic achievement. Several suggestions about the mechanism behind this association have been made, these highlighting for example, the fewer learning opportunities of cautious and wary children and more negative interaction between teachers and inhibited children. However, the empirical studies about these mechanisms are rare and, thus, they have remained unclear. This study examined whether children’s maths-related self-concept of ability acts as a mediator between their temperamental inhibiti…
Fixed point theorems for twisted (α,β)-ψ-contractive type mappings and applications
2013
The purpose of this paper is to discuss the existence and uniqueness of fixed points for new classes of mappings defined on a complete metric space. The obtained results generalize some recent theorems in the literature. Several applications and interesting consequences of our theorems are also given.
Parabolic equations with nonlinear singularities
2011
Abstract We show the existence of positive solutions u ∈ L 2 ( 0 , T ; H 0 1 ( Ω ) ) for nonlinear parabolic problems with singular lower order terms of the asymptote-type. More precisely, we shall consider both semilinear problems whose model is { u t − Δ u + u 1 − u = f ( x , t ) in Ω × ( 0 , T ) , u ( x , 0 ) = u 0 ( x ) in Ω , u ( x , t ) = 0 on ∂ Ω × ( 0 , T ) , and quasilinear problems having natural growth with respect to the gradient, whose model is { u t − Δ u + ∣ ∇ u ∣ 2 u γ = f ( x , t ) in Ω × ( 0 , T ) , u ( x , 0 ) = u 0 ( x ) in Ω , u ( x , t ) = 0 on ∂ Ω × ( 0 , T ) , with γ > 0 . Moreover, we prove a comparison principle and, as an application, we study the asymptotic behav…
Attitudes toward sad music are related to both preferential and contextual strategies.
2015
Music-related sadness and its paradoxical pleasurable aspects have puzzled researchers for decades. Previous studies have highlighted the positive effects of listening to sad music and the listening strategies that focus on mood-regulation. The present study explored people’s attitudes toward sad music by focusing on a representative sample of the Finnish population. Three hundred and fifty-eight participants rated their agreement with 30 statements concerning attitudes toward sad music. The ratings were subjected to factor analysis, resulting in 6 factors explaining 51% of the variance (RMSEA = 0.049). The factors were labeled Avoidance, Autobiographical, Revival, Appreciation, Intersubjec…
Are Facebook brand community members truly loyal to the brand?
2015
Investigates two Facebook brand communities and their relationship with loyalty.Community commitment is associated with community promotion behavior and loyalty.Community promotion behavior is associated with different types of loyalty.User activity in Facebook has little or no effect on brand loyalty. This study examines members of Facebook brand communities and tests the relationships between their commitment to the community and brand loyalty. A conceptual model on the linkages between brand community commitment, community promotion behavior and brand loyalty including attitudinal loyalty, repurchase intention and positive word-of-mouth (WOM) is developed and tested with two samples. Dat…