Heat Transport in Mesoscopic Systems

Phonon heat transport in mesoscopic systems is investigated using methods analogous to the Landauer description of electrical conductance. A "universal heat conductance" expression that depends on the properties of the conducting pathway only through the mode cutoff frequencies is derived. Corrections due to reflections at the junction between the thermal body and the conducting bridge are found to be small except at very low temperatures where only the lowest few bridge modes are excited. Various non-equilibrium phonon distributions are studied: a narrow band distribution leads to clear steps in the cooling curve, analogous to the quantized resistance values in narrow wires, but a thermal distribution is too broad to show such features.Comment: To be published in Superlattices and Microstructures, special issue in honor of Rolf Landauer, March 198

Renal cysts managed laparoscopically

Introduction: The transperitoneal laparoscopically management of renal cysts is presented. Materials and Methods: The retrospective study concerns 13 cases operated laparoscopically, during last year in our center. Special attention was paid for large cysts. In one patient the cyst was infected (E. Coli). Overall time for cysts resection was between 30 and 95 minutes, with a median of 63 minutes. Results: No mortality was recorded. No open surgery was necessary. Two postoperative complications are noted; a tiny uretheric urinary fistula dried after uretheric stenting and a necrotic perforation of ascending colon managed by right haemicolectomy. The patients were seen at 3 and 6 months postoperative. Conclusions: However, laparoscopic excision of renal cysts is generally accepted as a minimally invasive technique with similar results as open surgery

Parietal defects. Laparoscopic aproach

Spitalul Elias, București, România, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Experiența clinicii țn defectele parietale abdominale prin abord laparoscopic.Clinic experience in abdominal parieteal defects with laparoscopic aproach

The Effect of Surface Roughness on the Universal Thermal Conductance

We explain the reduction of the thermal conductance below the predicted universal value observed by Schwab et al. in terms of the scattering of thermal phonons off surface roughness using a scalar model for the elastic waves. Our analysis shows that the thermal conductance depends on two roughness parameters: the roughness amplitude $\delta$ and the correlation length $a$. At sufficiently low temperatures the conductance decrease from the universal value quadratically with temperature at a rate proportional to $\delta ^{2}a$. Values of $\delta$ equal to 0.22 and $a$ equal to about 0.75 of the width of the conduction pathway give a good fit to the data.Comment: 10 pages, 5 figures. Ref. added, typo correcte

Penetrating brain injury with 2 nails as an attempt of suicide

We report the case of a 47-year-old man that was admitted to our hospital secondary to a penetrating brain injury with 2 nails as an attempt of suicide. Emergency head CT scan revealed the presence of 2 nails intracranially. The patient underwent surgical removal of the nails by minimal craniectomy. The particularity of the case is the minimal invasiveness of the approach completed by specific follow-up imagistic studies to maximise the outcome

Large Deviations in the Superstable Weakly Imperfect Bose Gas

The superstable Weakly Imperfect Bose Gas {(WIBG)} was originally derived to solve the inconsistency of the Bogoliubov theory of superfluidity. Its grand-canonical thermodynamics was recently solved but not at {point of} the {(first order)} phase transition. This paper proposes to close this gap by using the large deviations formalism and in particular the analysis of the Kac distribution function. It turns out that, as a function of the chemical potential, the discontinuity of the Bose condensate density at the phase transition {point} disappears as a function of the particle density. Indeed, the Bose condensate continuously starts at the first critical particle density and progressively grows but the free-energy per particle stays constant until the second critical density is reached. At higher particle densities, the Bose condensate density as well as the free-energy per particle both increase {monotonously}

Self-esteem depends on beliefs about the rate of change of social approval

A major challenge in understanding the neurobiological basis of psychiatric disorders is rigorously quantifying subjective metrics that lie at the core of mental illness, such as low self-esteem. Self-esteem can be conceptualized as a ‘gauge of social approval’ that increases in response to approval and decreases in response to disapproval. Computational studies have shown that learning signals that represent the difference between received and expected social approval drive changes in self-esteem. However, it is unclear whether self-esteem based on social approval should be understood as a value updated through associative learning, or as a belief about approval, updated by new evidence depending on how strongly it is held. Our results show that belief-based models explain self-esteem dynamics in response to social evaluation better than associative learning models. Importantly, they suggest that in the short term, self-esteem signals the direction and rate of change of one’s beliefs about approval within a group, rather than one’s social position

Low-temperature heat transfer in nanowires

The new regime of low-temperature heat transfer in suspended nanowires is predicted. It takes place when (i) only ``acoustic'' phonon modes of the wire are thermally populated and (ii) phonons are subject to the effective elastic scattering. Qualitatively, the main peculiarities of heat transfer originate due to appearance of the flexural modes with high density of states in the wire phonon spectrum. They give rise to the $T^{1/2}$ temperature dependence of the wire thermal conductance. The experimental situations where the new regime is likely to be detected are discussed.Comment: RevTex file, 1 PS figur