Effect of annealing treatments on the anisotropy of a magnesium alloy sheet processed by severe rolling

The effect of annealing treatments on the normal plastic anisotropy (r-value) of a magnesium alloy, AZ61, processed by severe rolling was investigated. The various annealing treatments produce two effects on microstructure: grain coarsening and slight weakening of the texture. In addition, these treatments produce a noticeable decrease of the anisotropy that was correlated with an increase in strain rate sensitivity and a decrease of work hardening rate. It is concluded that an enhanced contribution of basal slip occurs as a consequence of the annealing treatments.The authors acknowledge the financial support from the CICYT grant MAT 2006-02672 awarded by the Spanish Ministry of Education and Science.Peer reviewe

НАДЕЖНОСТЬ КОНВЕЙРНОГО ТРАНСПОРТА

Досліджено питання комплексної надійності функціонування конвеєрних ліній при відкритій розробці корисних копалин. Наведено статистичні закони розподілу для напрацювання на відмову і термінів служби роликових опор для конвеєрних ліній. Побудовано діаграму причин і результатів для системати- зації причин простоїв конвейєрних ліній з переміщення гірської маси в кар'єрах. Исследован вопрос комплексной надежности функционирования конвейерных линий при открытой разра- ботке полезных ископаемых. Приведены статистические законы распределения для наработки на отказ и сроков службы роликовых опор для конвейерных линий. Построена диаграмма причин и результатов для систематизации причин простоев конвейерных линий по перемещению горной массы в карьерах

European association of echocardiography recommandations for standardization of performance, digital staorage and reporting of echocardiographic studies

peer reviewedIn view of the European Association of Echocardiography (EAE) mission statement “To promote excellence in clinical diagnosis, research, technical development, and education in cardiovascular ultrasound in Europe” and the increasing demand for standardization and quality control, the EAE have established recommendations and guidelines for standardization of echocardiography performance, data acquisition (images, measurements and morphologic descriptors), digital storage and reporting of echocardiographic studies. The aim of these recommendations is to provide a European consensus document on the minimum acceptable requirements for the clinical practice of echocardiography today and thus improve the quality and consistency of echocardiographic practice in Europe

Patterns of normal transvalvular regurgitation in mechanical valve prostheses

AbstractThe magnitude and spatial distribution of normal leakage through mechanical prosthetic valves were studied in an in vitro model of mitral regurgitation. The effective regurgitant orifice was calculated from regurgitant rate at different transvalvular pressure differences and flow velocities. This effective orifice area was 0.6 to 2 mm2for three tilting disc prostheses (Medtronic-Hall sizes 21, 25 and 29) and 0.2 to 1.1 mm2for three bileaflet valves (St. Jude Medical sizes 21, 25 and 33).In the single disc valves, Doppler color flow examination disclosed a prominent central regurgitant jet around the central hole for the strut, accompanied by minor leakage along the rim of the disc (central to peripheral jet area ratio 3.3 ± 1.2). The bileaflet prostheses showed a peculiar complex pattern: in planes parallel to the two disc axes, convergent peripherally arising jets were visualized, whereas in orthogonal planes several diverging jets were seen.Mounting the disc and bileaflet valves on a water-filled tube allowed reproduction and interpretation of this pattern: for the bileaflet valve, the jets originated predominantly from valve ring protrusions that contained the axis hinge points and created a converging V pattern in planes parallel to the leaflets and a diverging V pattern in orthogonal planes.Similar patterns were observed during transesophageal echocardiography in 20 patients with a normally functioning St. Jude prosthesis. In 10 patients with a Medtronic-Hall valve, a dominant central jet was observed with one or more smaller peripheral jets. The median central to peripheral jet area ratio was 5 to 1.In summary, in two types of mechanical valve prostheses, effective leakage orifice areas are reported and criteria proposed for the differentiation of “physiologic” and pathologic regurgitation based on the spatial configuration of the jets

Исследование кинетики превращения веществ в процессе гидроочистки дизельного топлива

Объектами исследования являются дизельное топливо с общим со-держанием серы 1,430 %; алюмоникельмолибденовый катализатор ГКД-202. Цель работы – изучение структурно группового состава дизельной фракции до и после процесса гидроочистки с целью нахождения кинетических параметров протекающих химических реакций. В процессе исследования проводился процесс гидроочистки дизельного топлива и анализ полученных продуктов. В результате исследования составлены схемы превращения серосо-держащих соединений дизельной фракции, рассчитаны константы скоростей превращения сернистых соединений в процессе гидроочистки дизельного топлива.The objects of research are diesel with common-with sulfur content of 1.430%; alyumonikelmolibdenovy catalyst GCD-202. Objective - study of the structural group composition diesel fraction before and after the hydrotreating process to find the kinetic parameters of the chemical reactions. The study was conducted diesel hydrotreating process and analysis of the resulting products. The study drawn up conversion circuits seroso-containing compounds of the diesel fraction, calculated conversion rate constants of sulfur compounds in the processes of Hydrotreating of diesel fuel

Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography

A

Three-dimensional transoesophageal echocardiography: how to use and when to use-a clinical consensus statement from the European Association of Cardiovascular Imaging of the European Society of Cardiology.

peer reviewedThree-dimensional transoesophageal echocardiography (3D TOE) has been rapidly developed in the last 15 years. Currently, 3D TOE is particularly useful as an additional imaging modality for the cardiac echocardiographers in the echo-lab, for cardiac interventionalists as a tool to guide complex catheter-based procedures cardiac, for surgeons to plan surgical strategies, and for cardiac anaesthesiologists and/or cardiologists, to assess intra-operative results. The authors of this document believe that acquiring 3D data set should become a 'standard part' of the TOE examination. This document provides (i) a basic understanding of the physic of 3D TOE technology which enables the echocardiographer to obtain new skills necessary to acquire, manipulate, and interpret 3D data sets, (ii) a description of valvular pathologies, and (iii) a description of non-valvular pathologies in which 3D TOE has shown to be a diagnostic tool particularly valuable. This document has a new format: instead of figures randomly positioned through the text, it has been organized in tables which include figures. We believe that this arrangement makes easier the lecture by clinical cardiologists and practising echocardiographers