1,480 research outputs found
Does urbanization matter in the expenditure-happiness nexus?
This study aims to improve the regional well-being literature on the so-called âreversal issueâ of the expenditure-happiness nexus, accounting for two main sources of heterogeneity: degree of urbanization and individual spending habits. Moreover, we investigate the role of happiness across the entire expenditure distribution using a quantile modelling approach. The results show that satisfaction has a positive, significant and non-linear effect on total expenditure across different urbanization categories. To better investigate the multidimensional nature of happiness, analysis of the nexus is expounded to different satisfaction domains and related spending aggregates offering a comprehensive and complex behavioural profile of individuals
Effect of grain refinement on enhancing critical current density and upper critical field in undoped MgB2 ex-situ tapes
Ex-situ Powder-In-Tube MgB2 tapes prepared with ball-milled, undoped powders
showed a strong enhancement of the irreversibility field H*, the upper critical
field Hc2 and the critical current density Jc(H) together with the suppression
of the anisotropy of all of these quantities. Jc reached 104 A/cm2 at 4.2 K and
10 T, with an irreversibility field of about 14 T at 4.2 K, and Hc2 of 9 T at
25 K, high values for not-doped MgB2. The enhanced Jc and H* values are
associated with significant grain refinement produced by milling of the MgB2
powder, which enhances grain boundary pinning, although at the same time also
reducing the connectivity from about 12% to 8%. Although enhanced pinning and
diminished connectivity are in opposition, the overall influence of ball
milling on Jc is positive because the increased density of grains with a size
comparable with the mean free path produces strong electron scattering that
substantially increases Hc2, especially Hc2 perpendicular to the Mg and B
planes.Comment: 26 pages, 9 figures, submitted to J. Appl. Phy
Poverty-happiness nexus: Does the use of regional poverty lines matter?
This analysis aims to provide a comprehensive representation of the role of regional disparities in the nexus between poverty and subjective well-being, by adding the territorial dimension to the definition of poverty conditions. We investigate the nexus using regional poverty lines, including different poverty measures and considering different life domains. The analysis focuses on Italy because of its strong regional socio-economic disparities. Results show that the relevance of being poor on the well-being of citizens is in general higher and significant; the intensity and severity of poverty also change for different life domains. Findings are fundamental in designing local policies against poverty
Thermal properties of MgB2: the effect of disorder on gap amplitudes and relaxation times of p and s bands
We present thermal conductivity and specific heat measurements on MgB2 and
Mg-AlB2 samples. Thermal properties have been analysed by using a two-gap model
in order to estimate the gap amplitudes, D(0)p and D(0)s and the intra-band
scattering rates, Gss and Gpp. As a function of Al doping and disorder D(0)s
rapidly decreases, while D(0)p is rather constant. Gss and Gpp are increased by
the disorder, being Gpp more affected than Gss.Comment: 2 pages, 3 figures, presented to the conference M2S-HTSC, 25-30 May
2003, Rio de Janeir
Towards Micromechanical Sensors with (La,Sr)MnO3 Epitaxial Filmsâ
Abstract The rich spectrum of functionalities exhibited by oxide thin films is an appealing feature for the development of micro and nanomechanical devices [1,2] . MEMS made of heterostructures of crystalline oxide materials having targeted physical properties may be applied as sensors having different integrated functionalities. In this work, we explore the feasibility of manganite thin film based epitaxial MEMS for magnetic micromechanical sensing. We investigate the electromechanical properties of LSMO freestanding structures for future applications in the field of micromechanical magnetic sensors
Low-field Instabilities in NbSn Multifilamentary Wires: the Possible Role of Unreacted Nb
We report an experimental study aiming to demonstrate the not negligible role of unreacted Nb on the magnetic instabilities in superconducting NbSn multifilamentary wires, observable through partial flux jumps at magnetic field values below 0.5 T. The analysed wires were recently developed for use as dipoles required in future high-energy proton accelerators and are based on powder-in-tube technology. We studied both unreacted (only involving Nb filaments) and reacted wires, finding flux jump instabilities in both cases when performing magnetic measurements. The results can be interpreted on the basis of the critical state model and are coherent with the intrinsic stability criterion
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