Search

The transition processes of the centrifugal pump in hydro accumulation power plant (HAPP) are studied in the article. The reliability of the pumping system is increased by the correct selection of the parameters of the transition process when regulating the operation of the pumping units. This prevents vibration damage and erosion. Based on the results obtained by calculating the hydraulic shock and the pressure loss in the system together, damage and failures in the pumping equipment and the network can be avoided. The results and graphs allow you to choose the right electric motor for the pump unit, taking into account the required pressure and water supply. Technical and economic efficiency is achieved by choosing a rated electric motor for the pump unit. Constructing graphic descriptions of the pump, determined the magnitude of the hydraulic effect in the grapho-analytical method.

Copyright of Matériaux et Techniques is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Petroleum drilling rigs are used for identifying geologic reservoirs and for creating wells for extraction. The mud pumps of drilling rigs are operated at high mud rates to make possible the drilling process. The durability of the mud pump valves to erosive wear, due to the action of abrasive drilling fluid containing solid particles, depends on their constructive form and on the mud flow velocity. This paper analyzes a few methods of increasing the wear resistance of mud pump valves.

Résumé Le nez et les fosses nasales assurent la ventilation, le conditionnement de l’air inspiré et l’olfaction. Ils peuvent être le siège de pathologies inflammatoires, infectieuses et tumorales ou d’anomalies architecturales préopératoires voire postopératoires, altérant ces fonctions, pour lesquelles l’examen clinique sera d’un rendement variable. Nous verrons tout d’abord, après un bref rappel physiologique, l’examen dit « de débrouillage » qui permettra au chirurgien non ORL de sélectionner les patients justifiant d’une exploration fonctionnelle préopératoire plus poussée. Nous présenterons ensuite les explorations complémentaires existantes : consultation ORL et endoscopie des fosses nasales, imagerie, technique de mesure du flux aérien nasal. À l’issue de ce bilan complémentaire, le praticien doit être en mesure : de savoir s’il existe ou non une obstruction nasale préopératoire et de la quantifier et de la rattacher à une cause, de dépister les contre-indications à la rhinoplastie mais aussi de connaître les structures anatomiques pouvant être à l’origine de troubles ventilatoires postopératoire, de prévoir d’emblée un geste adapté, qu’il soit esthétique pur ou esthético-fonctionnel. Au total, il existera 3 groupes de patients : ceux qui ne présentent aucune contre-indication au geste de rhinoplastie, ceux qui présentent une indication de geste esthético-fonctionnel, ceux qui présentent une contre-indication à la rhinoplastie. Summary Nose and nasal cavity provide ventilation, inspired air conditioning and olfaction. They may be the seat of inflammatory, infectious and malignant disease, or preoperative or postoperative architectural abnormalities, altering these functions, for which clinical examination will be a variable return. First of all, we’ll see, after a brief physiological reminder, descrambling examination which allows non-ENT surgeon to select patients justifying a further preoperative functional exploration. In total, there will be three groups of patients: those who have no cons-indication to rhinoplasty, those with an indication of aesthetic and functional rhinoseptoplasty, those with cons-indication for rhinoplasty. [ABSTRACT FROM AUTHOR]

Introduction: Percutaneous aortic valve replacement has been performed in daily practice for less than 10 years. This technique was until recently reserved for patients with very high surgical risk. There is little data in the literature documenting the impact of this percutaneous technique on the patient population continuing to benefit from a surgical replacement of the aortic valve. We studied the characteristics of these patients immediately before and after the introduction of the percutaneous technique in the CHU Brugmann., Materials and Methods: Two separate cohorts of patients were retrospectively studied: one before the percutaneous era between 2005 and 2010 and the other after introduction of the percutaneous technique in our daily practice between 2010 and 2015. Demographic, intraoperative, mortality and postoperative morbidity indices were compared., Results: The number of surgical replacements of the aortic valve was 194 before and 132 after introduction of the percutaneous technique. The demographic, operative characteristics and postoperative morbidity and mortality of the patients remained the same between the two cohorts. Only the incidence of pulmonary arterial hypertension (12.1 vs 25 %, p = 0.015) and recent myocardial infarction (0 vs 3 %, p = 0.003) were higher in the second cohort., Conclusion: Replacement of the aortic valve percutaneously did not significantly change the demographic characteristics and postoperative morbidity and mortality of patients candidate for surgical replacement of the aortic valve. Nevertheless, after its introduction, the number of surgical replacements dropped considerably in our center.

Nose and nasal cavity provide ventilation, inspired air conditioning and olfaction. They may be the seat of inflammatory, infectious and malignant disease, or preoperative or postoperative architectural abnormalities, altering these functions, for which clinical examination will be a variable return. First of all, we'll see, after a brief physiological reminder, descrambling examination which allows non-ENT surgeon to select patients justifying a further preoperative functional exploration. In total, there will be three groups of patients: those who have no cons-indication to rhinoplasty, those with an indication of aesthetic and functional rhinoseptoplasty, those with cons-indication for rhinoplasty., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)