16,345 research outputs found
Electromagnetism and multiple-valued loop-dependent wave functionals
We quantize the Maxwell theory in the presence of a electric charge in a
"dual" Loop Representation, i.e. a geometric representation of magnetic
Faraday's lines. It is found that the theory can be seen as a theory without
sources, except by the fact that the wave functional becomes multivalued. This
can be seen as the dual counterpart of what occurs in Maxwell theory with a
magnetic pole, when it is quantized in the ordinary Loop Representation. The
multivaluedness can be seen as a result of the multiply-connectedness of the
configuration space of the quantum theory.Comment: 5 page
Determination of compressor in-stall characteristics from engine surge transients
A technique for extracting the in-stall pumping characteristics for an axial flow compressor operating in an engine system environment is developed. The technique utilizes a Hybrid computer simulation of the compressor momentum equation into which actual transient data are used to provide all terms but the desired compressor characteristic. The compressor force characteristic as a function of corrected flow and speed result from the computation. The critical problem of data filtering is addressed. Results for a compressor operating in a turbofan engine are presented and comparison is made with the conventional compressor map. The relationship of the compressor surge characteristic with its rotating stall characteristic is explored. Initial interpretation of the measured results is presented
Orthorexia nervosa and self-attitudinal aspects of body image in female and male university students.
The present study was designed to investigate orthorexia nervosa, or the phenomenon of being preoccupied with consuming healthy food. Specific aims were to explore relationships between orthorexia features and attitudes towards body image, fitness and health in normal weight female and male university students with high levels of healthy food preoccupation, i.e. orthorexia nervosa.
METHODS Participants were 327 female (N = 283) and male (N = 44) students aged 18 to 25 years. All participants completed the Polish adaptation of the 15-item questionnaire assessing orthorexia eating behaviours (the ORTHO-15) and the Multidimensional Body-Self Relations Questionnaire (the MBSRQ). Relationships between scores on the ORTHO-15 and MBSRQ were explored in the 213 students who had high levels of preoccupation with a healthy food intake (68.55% women and 43.18% men, respectively).
RESULTS: There were no statistically significant differences in the levels of orthorexia behaviours between females and males. In female students with orthorexia nervosa, preoccupation with consuming healthy food was significantly correlated with the MBSRQ subscale scores for overweight preoccupation, appearance orientation, fitness orientation, health orientation, body areas satisfaction and appearance evaluation. Conversely, in male students with orthorexia nervosa there were no correlations between orthorexic behaviours and the MBSRQ subscales. In female students with orthorexia nervosa multivariable linear regression analysis found high body areas (parts) satisfaction, low fitness orientation, low overweight preoccupation and low appearance orientation were independent predictors of greater fixation on eating healthy food. In male students, we found that aspects of body image were not associated with preoccupation with healthy eating.
CONCLUSION: A strong preoccupation with healthy and proper food was not associated with an unhealthy body-self relationship among Polish female student with orthorexia nervosa
Bures metric over thermal state manifolds and quantum criticality
We analyze the Bures metric over the manifold of thermal density matrices for
systems featuring a zero temperature quantum phase transition. We show that the
quantum critical region can be characterized in terms of the temperature
scaling behavior of the metric tensor itself. Furthermore, the analysis of the
metric tensor when both temperature and an external field are varied, allows to
complement the understanding of the phase diagram including cross-over regions
which are not characterized by any singular behavior. These results provide a
further extension of the scope of the metric approach to quantum criticality.Comment: 9 pages, 4 figures, LaTeX problems fixed, references adde
Patterns of variability in early life traits of a Mediterranean coastal fish
Spawning dates and pelagic larval duration (PLD) are early life traits (ELT) crucial for understanding life cycles, properly assessing patterns of connectivity and gathering indications about patchiness or homogeneity of larval pools. Considering that little attention has been paid to spatial variability in these traits, we investigated variability of ELT from the analysis of otolith microstructure in the common two-banded sea bream Diplodus vulgaris. In the southwestern Adriatic Sea, along ~200 km of coast (∼1° in latitude, 41.2° to 40.2°N), variability of ELT was assessed at multiple spatial scales. Overall, PLD (ranging from 25 to 61 d) and spawning dates (October 2009 to February 2010) showed significant variability at small scales (i.e. <6 km), but not at larger scales. These outcomes suggest patchiness of the larval pool at small spatial scales. Multiple causal processes underlying the observed variability are discussed, along with the need to properly consider spatial variability in ELT, for example when delineating patterns of connectivity. Copyright © 2013 Inter-Research
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