Normal ranges for automated analysis of global LV function using 2D Strain

Background: Automated measurement of LV function could extend the clinical utility of echo by less expert readers. We sought to define normal ranges of global 2D strain (2DS) and strain-rate (SR) in an international, multicenter study of healthy subjects, and to assess the determinants of variation. Methods: SR and 2DS were measured in 18 myocardial segts in both apical and short axis views of 227 normal subjects (38% men, 48±14y) with no cardiac history, risk factors or drug therapy. The association of age and resting hemodynamics with global strain indices was sought using multiple regression. Differences in variance were expressed as F values. Results: Baseline SBP was 127±18 mmHg, pulse was 76±13/min and ejection fraction 50±20%. Although global longitudinal strain was influenced by endsystolic volume (F=4.2, p

Power quality improvements for LV networks

In order to increase the capacity of the existing Low Voltage grid, one solution is to increase the nominal residential network voltage from 230 V to 300 V, which is easily accommodated within the voltage rating of existing infrastructure such as cabling. A power electronic AC-AC converter would then be used to step the voltage back down to 230 V at an individual property. Such equipment could also be used to provide power quality improvements on both the utility and customer side of the converter depending on its topology. This paper provides an overview of a project which is looking at the development of such a device. The project is being carried out in collaboration with the local UK, Distribution Network Operator (DNO).

High efficiency SiC AC chopper for LV networks

A proposal to increase the existing residential LV grid voltage from 230 V has been made in order to increase existing network capacity. A power-electronic AC-AC converter is then used to provide 230 V at each property. Several constraints such as temperature rise at the converter location lead to a converter design requiring very high efficiency. In this paper results from a recent feasibility study in terms of LV network capacity increase are presented along with the design and testing of a SiC based 1 kW, AC/AC prototype module, which forms the basis of a much larger 15 kW multi-module converter.

Connection design without accurate LV feeder load data:an argument for LV monitoring

Since privatisation, maintenance of DNO LV feeder maximum demand information has gradually demised in some Utility Areas, and it is postulated that lack of knowledge about 11kV and LV electrical networks is resulting in a less economical and energy efficient Network as a whole. In an attempt to quantify the negative impact, this paper examines ten postulated new connection scenarios for a set of real LV load readings, in order to find the difference in design solutions when LV load readings were and were not known. The load profiles of the substations were examined in order to explore the utilisation profile. It was found that in 70% of the scenarios explored, significant cost differences were found. These cost differences varied by an average of 1000%, between schemes designed with and without load readings. Obviously, over designing a system and therefore operating more, underutilised transformers becomes less financially beneficial and less energy efficient. The paper concludes that new connection design is improved in terms of cost when carried out based on known LV load information and enhances the case for regular maximum feeder demand information and/or metering of LV feeders. © 2013 IEEE.

A forgalomban lévő fásszárú dísznövénytaxonok szárazságtűrésének értékelése a klímaváltozás tükrében (Evaluation of the impact climate change on current drought-tolerant woody plants)

Regionális klímaváltozási forgatókönyvek szerint hazánk éghajlata az elkövetkező 90 évben a mainál jóval melegebb, a nyári évszakban csapadékszegényebb, összességében pedig szárazabb lesz. Kutatásunk célja volt felmérni szárazságtűrésük szerint a legjelentősebb faiskolák katalógusában fellelhető fa- és cserjefajokat (a gyűjtésben nem szerepelnek a faj alatti taxonok). A vizsgálatainkban szereplő öt faiskola növénykínálatát a tudományos nevek ellenőrzése után összesítettük, majd ezt követően az egyes fajokat vízigény szerinti kategóriákba soroltuk. A tényleges statisztikai értékelésbe – a 451 összegyűjtött faj tudományos neveinek ellenőrzése után – 420 fajt vontunk be, melyek 20%-a vízigényes, 53%-a közepesen vízigényes és 27%-a szárazságtűrő. Várakozásainkkal ellentétben a vízigényes fajok részaránya kevésnek mondható, ugyanakkor a szárazságtűrő fajok magasabb aránya kívánatos lenne. Ezért, a gyakorlati alkalmazást elősegítve, kiemeltünk olyan nemzetségeket, melyek kereskedelmi forgalmazását meg kellene kezdeni vagy fokozni, mint pl a Cupressus, Eucommia, Halimodendron, Paliurus, Pyrus, Rhus, Yucca Zanthoxylum, Zelkova, illetve olyanokat, melyek telepítését a jövőben nem, vagy csak kellő körültekintéssel javasoljuk, mint például a Clematis, Hydrangea, Liquidambar, Magnolia, Rhododendron nemzetségek. _____ According to regional climate change scenarios, the climate in Hungary will be warmer. Less precipitation is predicted in the summer seasons so, on the whole, it will be drier over the next 90 years. Our research attempted to survey the ornamental plant species in the most important nurseries in Hungary, in terms of their drought tolerance. The intraspecifi c taxa are not included. The plant assortment of the fi ve nurseries was merged after researching their scientifi c names. We then categorized species to 3 groups of drought tolerance. Out of 451 species, 420 of them were used in the statistical research. 20% of them were water demanding, 53% were medium drought tolerant and 27% were drought tolerant. In contrast to our initial expectation, the proportion of water demanding species was not too high. Nevertheless, the proportion of drought tolerant species should have been greater. We classifi ed the genera to assist in practical application. The trade of some of these species, such as Cupressus, Eucommia, Halimodendron, Paliurus, Pyrus, Rhus, Yucca, Zanthoxylum, Zelkova should be initiated or increased in the future. Other species, especially Clematis, Hydrangea, Liquidambar, Magnolia, Rhododendron are not recommended due to either their drought intolerance or their high maintenance requirement.