294 research outputs found
Borderline and schizotypal traits in college students: Relationship and personality profiles
The relationships between borderline and schizotypal traits are still debated. Borderline traits, schizotypal traits, and several psychopathological symptoms were assessed among 2,341 college students. A factor analysis was performed on borderline and schizotypal personality measures, leading to 10 factors. Borderline factors were largely intercorrelated, as were schizotypal factors. Moreover, borderline factors were weakly to largely correlated to schizotypal factors. Five factors were very strongly correlated (r > .50). Dissociation was strongly related to Odd Beliefs/Unusual Perceptive Experiences and Anxious-Depressive factors. Social Anxiety was strongly related to Suspiciousness. Based on these 10 factors, a cluster analysis was conducted, and resulted in four clearly distinct groups: a Low Traits cluster, a Narcissistic cluster, a Social Anxiety cluster, and a High Traits cluster. This High Traits cluster had the lowest levels of academic achievement and the highest levels of internalizing behaviors and externalizing behaviors. The clinical implications of the results are discussed
Investigation on reconstruction methods applied to 3D terahertz computed tomography
International audience3D terahertz computed tomography has been performed using a monochromatic millimeter wave imaging system coupled with an infrared temperature sensor. Three different reconstruction methods (standard back-projection algorithm and two iterative analysis) have been compared in order to reconstruct large size 3D objects. The quality (intensity, contrast and geometric preservation) of reconstructed cross-sectional images has been discussed together with the optimization of the number of projections. Final demonstration to real-life 3D objects has been processed to illustrate the potential of the reconstruction methods for applied terahertz tomography
Dielectrophoresis of charged colloidal suspensions
We present a theoretical study of dielectrophoretic (DEP) crossover spectrum
of two polarizable particles under the action of a nonuniform AC electric
field. For two approaching particles, the mutual polarization interaction
yields a change in their respective dipole moments, and hence, in the DEP
crossover spectrum. The induced polarization effects are captured by the
multiple image method. Using spectral representation theory, an analytic
expression for the DEP force is derived. We find that the mutual polarization
effects can change the crossover frequency at which the DEP force changes sign.
The results are found to be in agreement with recent experimental observation
and as they go beyond the standard theory, they help to clarify the important
question of the underlying polarization mechanisms
Electronic structure of wurtzite and zinc-blende AlN
The electronic structure of AlN in wurtzite and zinc-blende phases is studied
experimentally and theoretically. By using x-ray emission spectroscopy, the Al
3p, Al 3s and N 2p spectral densities are obtained. The corresponding local and
partial theoretical densities of states (DOS), as well as the total DOS and the
band structure, are calculated by using the full potential linearized augmented
plane wave method, within the framework of the density functional theory. There
is a relatively good agreement between the experimental spectra and the
theoretical DOS, showing a large hybridization of the valence states all along
the valence band. The discrepancies between the experimental and theoretical
DOS, appearing towards the high binding energies, are ascribed to an
underestimation of the valence band width in the calculations. Differences
between the wurtzite and zinc-blende phases are small and reflect the slight
variations between the atomic arrangements of both phases
The effect of yeast on the anthocyanin characteristics of fermented model solutions
The sensory quality of red wines is basically determined by the colour, which depends on the amount and on the evolution of anthocyanins and other phenolic compounds extracting from the berries into the wine during wine-making. The anthocyanin-monomers are responsible for the development of the red colour, and their acylated derivatives provide stability for the colour of the wines. The anthocyanin profile of wines is affected by several factors: the grape variety, the conditions during wine-making, and also the yeast culture used for the fermentation. In our experiments a self-compiled model solution was fermented by spontaneous fermentation, as well as by four commercial yeasts under laboratory conditions. After fermentation total polyphenolics, anthocyanins, anthocyanin monomer profile, colour intensity, hue, and the ratio of polymeric anthocyanins were studied. Our results show that the spontaneous yeast fermentation resulted in a higher anthocyanin concentration in the fermented model solution, but the commercial yeast strains provided a more advantageous colour characteristic compared to the spontaneous fermentation. After the spontaneous fermentation less sediment was left than in the commercial yeast fermented samples
Characterization of Fabric-to-Fabric Friction: Application to Medical Compression Bandages
Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics
Polarimetric interferometer for nanoscale positioning applications
International audienceWe propose and demonstrate a displacement control method at the subnanometric scale based on a Michelson interferometer combined with a polarimeter and a phase-locked loop electronic board. Step by step displacements with a step value of 5 nm are presented. A repeatability of 0.47 nm is obtained from back and forth displacements over 1 m range. We show that a residual ellipticity of less than 10° on the polarization state leads to a positioning error of less than 1 nm. Such system could be used over millimeter range displacements in a controlled surrounding environment leading to numerous applications in nanometrology
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