Transient nucleate boiling under stepwise heat generation for highly wetting fluids

Experiments of transient nucleate boiling are carried out on highly wetting fluids from two metallic specimen, a thick flat sample and a wire. The initial condition is controlled in terms of the system temperature as well as by a primary activation of the nucleation sites. A stepwise heat generation is investigated and the role of thermal inertia is clarified. The thermal behaviour of the system and the associated time scales are found to depend on temperature at boiling inception. This one is similar to the steady-state value for the thick flat sample but depends on the magnitude of the heating step in the case of the thin wire.     

Transient natural convection and conjugate transients around a line heat source

Transient natural convection in liquid nitrogen around a heated wire is studied experimentally and numerically. A thin bronze wire of 40 μm in diameter and 5.1 cm in length heated by Joule effect is used in experiments and time evolutions of the wire temperature are measured through its electrical resistance. Numerical simulations of such flows are performed by using velocity-pressure formulation, spectral methods and domain decomposition technique. Experimental data and numerical results are compared and show that although the wire is extremely thin its thermal inertia plays an important role during early transients.Scaling analyses performed for the convection set-up and transients yield t∼q^−1/2 and ΔT∼q^3/4, which are confirmed by numerical simulations.For wires heated by Joule effect hybrid thermal conditions--combined Dirichlet and Neumann conditions are proposed on the wire surface and validated by numerical simulations. On the other hand flow conditions to be imposed on the outer artificial boundary are not well known and the answer to the question remains still open: two types of flow conditions are tested and yield different velocity fields.     

Cognitive-Behavioral Therapy for Insomnia: Comparison of Individual Therapy, Group Therapy, and Telephone Consultations.

Forty-five adults with primary insomnia received cognitive-behavioral therapy (CBT) implemented in a group therapy format, in individual face-to-face therapy or through brief individual telephone consultations. The results indicate that CBT was effective in improving sleep parameters with all 3 methods of treatment implementation, and there was no significant difference across methods of implementation. All 3 treatment modalities produced improvements in sleep that were maintained for 6 months after treatment completion. These results suggest that group therapy and telephone consultations represent cost-effective alternatives to individual therapy for the management of insomnia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatigue following traumatic brain injury: Frequency, characteristics, and associated factors.

Objectives: To document the frequency, characteristics, and factors associated with fatigue following traumatic brain injury (TBI). Design: Survey methodology and multivariate statistical design. Setting: Rehabilitation center and community. Participants: 452 participants aged 16 years and over with minor to severe TBI who answered a questionnaire measuring diverse aspects of fatigue as well as different dimensions of psychological distress, pain, and sleep quality. Measures: Proportion of participants reporting being significantly fatigued. Validated measures of fatigue, sleep quality, and psychological distress. Results of a logistic regression analysis. Results: Significant fatigue was reported by 68.5% of participants. Mental fatigue was the most prominent type of fatigue, followed by physical fatigue. Fatigue was present even several years following the accident and had many perceived impacts on day-to-day function. Factors associated with fatigue were a shorter time since injury; being on long-term disability leave; and higher levels of sleep problems, cognitive disturbances, and anxiety. Conclusion: Fatigue is a prevalent problem after TBI that requires more clinical and scientific attention because it probably has important repercussions on the quality of rehabilitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do milking practices influence the bacterial diversity of raw milk?

The link between milk production practices and bacterial diversity of 67 raw milks from dairy farms in the Savoie and Haute-Savoie regions of France was studied by Single Strand Conformation Polymorphism (SSCP) analysis. The milking practices and the cleanliness of different parts of the cow housing were evaluated. The SSCP bacterial profiles allow to classify the 67 milks into three groups: group A was characterised by a majority of Gram-positive non-lactic acid bacteria (Corynebacterineae and Micrococcaceae) and a high level of hygiene in milking practices. The SSCP profiles of groups B and C were close but different from those of group A: they were both dominated by lactic acid bacteria and by a less intensive hygiene practices. The group B milks were characterised by the dominance of Gram-negative bacteria and Lactococcus lactis species while those of group C were dominated by Brevibacterium linens and Leuconostoc mesenteroides. The variation of balance between bacterial populations can be associated with differences in hygienic milking production practices.     

Reconstruction of three-dimensional data for electrical impedance tomography

A two-dimensional reconstruction algorithm based on a modified version of the method of sensitivity regions is used to reconstruct data obtained from a three-dimensional finite element model. By using data obtained from off-drive-plane measurements an improved image of changes in resistivity on the drive plane is obtained.<>     

A Sequence-Based Object-Oriented Model for Video Databases

Structuration, annotation and composition are amidst the most crucial modeling issues that video editing and querying in the context of a database entail. In this paper, we propose a sequence-based, object-oriented data model that addresses them in an unified, yet orthogonal way. Thanks to this orthogonality, the interactions between these three aspects are properly captured, i.e., annotations may be attached to any level of video structuration, and all the composition operators preserve the structurations and annotations of the argument videos. We also propose to query both the structuration and the annotations of videos using an extension of ODMG's OQL which integrates a set of algebraic operators on sequences. The overall proposal is formalized and implemented on top of an object-oriented DBMS.     

Diversity of lactic acid bacteria isolated from AOC Salers cheese

The objective of this work was to describe the diversity of lactic acid bacteria in traditional raw milk Salers cheeses at the species and strain levels. The characterization of 381 strains isolated during ripening and various strain collections was investigated using physiological analysis and molecular techniques: Rep-PCR, species and genus specific amplifications and the sequence analysis of 16S rDNA for strain typing and taxonomic identification. The strains belonged to Lactobacillus plantarum, Lactobacillus paracasei, Lactococcus lactis, Lactococcus garviae, Enterococcus faecalis, Enterococcus faecium, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, Streptococcus salivarius, Streptococcus millieri, Streptococcus macedonicus and Pediococcus pentosaceus. A wide phenotypic and genomic heterogeneity was observed within the different species (Lactobacillus plantarum, Lactobacillus paracasei and Leuconostoc mesenteroides) according to the origin and the time of ripening. The natural microflora was different from strain collection and each method must be combined to identify and characterize natural microflora. This study revealed the low selectivity of selective media used for the isolation of different groups of lactic acid bacteria except the Facultatively Heterofermentative lactobacilli medium selecting mesophile lactobacilli and SB medium selective for Enterococcus. The study reveals, for the first time, the microbial lactic acid bacteria community of Salers cheese and its diversity. A better knowledge of microbial flora will be useful to improve understanding of sensory quality of cheeses.