Direct Experimental Evidence of the Statistical Nature of the Electron Gas in Superconducting Films

In an Nb film an alternate electrical current is partitioned at a Y-shaped obstacle into two splitted beams. The intensity-fluctuation correlation of the two beams (cross-correlation) and the intensity- fluctuation correlation of one beam (auto-correlation) are measured within a low-frequency bandwidth as a function of the incident beam intensity, at temperatures T above or below the temperature Tc of the superconductive transition. The results of these measurements reveal the statistical nature of the electron gas in the normal film and in the superconducting film. The conceptual scheme of the present experiment is a version of the Hanbury Brown and Twiss (HBT) experiment, here adopted for a gas of particles in a solid

The usability of ventilators: a comparative evaluation of use safety and user experience

Setup of the testing facilities at the Clinical Skills and Patient Simulation Center at the University of North Carolina School of Medicine, where the simulator room and observation room can be seen. (TIF 9461 kb

Local allergic rhinitis: entopy or spontaneous response?

Background The existence of a local allergic rhintis was proposed on the basis of the detection of nasal IgE in the absence of a systemic sensitization. Nevertheless, the significance of this phenomenon remains still unclear.We assessed the presence of mucosal nasal IgE in patients with ascertained allergic rhinitis, nonallergic rhinitis with inflammation and in healthy controls.Methods Consecutive patients with a well ascertained diagnosis (clinical history, skin prick test, specific IgE assay, nasal endoscopy, nasal cytology) underwent an immunoenzymatic measurement of specific IgE to grass, cypress, parietaria and olive in nasal scrapings.Results Fifteen patients with allergic rhinitis, 12 with non allergic rhinitis and 14 healthy subjects were studied. The patients with allergic and nonallergic rhinitis had higher nasal symptoms as compared to control subjects. Systemic sensitizatition (assessed by skin test and CAP-RAST) was obviously more frequent in allergic rhinitis, than in the other two groups. Allergen-specific nasal IgE could be detected in all groups (86,7, 33,3, and 50 % positive, respectively), even more frequently in the control group than in nonallergic rhinitis patients. No difference among allergens was identified. Out of the 26 non-allergic patients (non allergic rhinitis + controls) nasal IgE were positive in 11(42 %).Discussion According to the results, the presence of nasal IgE against allergens seems to be a non-specific phenomenon, since they can be detected also in non allergic rhinitis and in healthy subjects.Conclusion It can be hypothesized that the nasal IgE production represents a form of spontaneous immune response. Keywords: Allergic rhinitis, Nonallergic rhinitis, Sensitization, Nasal IgE, Local allergic rhinitis, Entop

Usability of Paper-based Industrial Operating Procedures

Procedures are standardized lists of instructions that designate the safe and accepted way of accomplishing a task. This study intended to develop and compare the usability of paper-based industrial operating procedures. Two procedures at a plant were redesigned with evidence-based guidelines and human factors input. 16 operators of varying experience were asked to read through and assess the new and old procedures. The new procedures were rated significantly or moderately better than their predecessors for efficiency, effectiveness, and subjective satisfaction. On average, inexperienced operators reported fewer inaccuracies, more confusion, and higher workload ratings than their experienced counterparts, regardless of procedure type or area. For satisfaction, experienced and inexperienced operators reported similar ratings across both procedure types and areas. Future studies should attempt to discern which particular change in the procedures contributed the most to increased usability, and whether operator experience significantly correlates with usability ratings.MAS

Current balancing of cascaded H-bridge converters for PV systems with partial shading

Purpose – The purpose of this paper is to propose a new converter topology for integrating PV plants constituted by many panels into the grid. The converter is capable of implementing MPPT algorithms on different subset of modules and can balance the different energy supplied by panels differently irradiated. The output voltage presents a very low ripple also if small filters are used for grid connection. Design/methodology/approach – In the paper, at first the converter configuration is presented. Then a control strategy for obtaining, at the same time the distributed MPPT and the power balancing on the three phases is proposed. Finally, by means of numerical simulations, the good performances of the proposed converter are shown. Findings – The proposed converter, lent from MMC configurations, is deeply studied and a suitable control strategy is well analyzed in the paper. Analytical model for voltage and current balancing are given