scholarly journals Analysis of severe convective events from two operational dual polarisation doppler radars

2006 ◽  
Vol 6 (3) ◽  
pp. 397-405
Author(s):  
M. Celano ◽  
P. P. Alberoni ◽  
V. Levizzani ◽  
A. R. Holt
Keyword(s):  
Temperature Field ◽  
Classification Scheme ◽  
Gradual Increase ◽  
Severe Storms ◽  
Cloud Systems ◽  
Po Valley ◽  
Radar Systems ◽  
Field Estimation ◽  
Points Of View

Abstract. The recent gradual increase in the use of polarimetric radars prompts for possible improvements in the estimation of precipitation and the identification of the prevailing hydrometeor type. An analysis of different convection episodes (20 May 2003, 4 and 7 May 2004) is conducted in order to explore the attenuation effects at C band and their consequences on the rainfall field estimation using two polarimetric radars in the Po Valley, Italy, located about 90 km apart. A hydrometeor classification scheme, developed at the National Severe Storms Laboratory (NSSL), is used to detect the microphysical structure of the different cloud systems. The work is focused on the reconstruction of the 3-D organisation of the convective events, highlighting how the two radar systems ''see'' the storms from different points of view. Furthermore, the two distinct observations and the temperature field are used to correct the effect of attenuation.

Heat Flux and Temperature Field Estimation Using Differential Interferometer

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
S. Prasanna ◽  
S. P. Venkateshan
Keyword(s):  
Heat Flux ◽  
Temperature Field ◽  
Fourier Transforms ◽  
Gradient Field ◽  
Two Dimensional ◽  
Convective Heat Flux ◽  
Field Temperature ◽  
Field Estimation ◽  
Least Squares Approach

A new methodology based on least-squares approach has been developed to estimate the temperature field from an interferogram recorded using a Differential interferometer (DI). The interferograms are digitally evaluated using two dimensional Fourier transforms to retrieve the temperature gradient field. Temperature field is constructed by fitting a cubic spline to the first derivatives data. The methodology has been applied to both experimental and synthetic interferograms. Both convective heat flux and temperature field were predicted accurately. The role of image noise and errors in the temperature measurements on the temperature field estimation have been studied with the aid of synthetic interferograms.

scholarly journals Why Italy First? Health, Geographical and Planning Aspects of the COVID-19 Outbreak

2020 ◽  
Vol 12 (12) ◽  
pp. 5064 ◽  
Author(s):  
Beniamino Murgante ◽  
Giuseppe Borruso ◽  
Ginevra Balletto ◽  
Paolo Castiglia ◽  
Marco Dettori
Keyword(s):  
Spatial Association ◽  
Analytical Techniques ◽  
Po Valley ◽  
Italian Case ◽  
Containment Measures ◽  
Points Of View ◽  
Socio Economic Variables ◽  
Valley Area ◽  
And Diffusion ◽  
Related Mortality

COVID-19 hit Italy in February 2020 after its outbreak in China at the beginning of January. Why was Italy first among the Western countries? What are the conditions that made Italy more vulnerable and the first target of this disease? What characteristics and diffusion patterns could be highlighted and hypothesized from its outbreak to the end of March 2020, after containment measures, including a national lockdown, were introduced? In this paper, we try to provide some answers to these questions, analyzing the issue from medical, geographical and planning points of view. With reference to the Italian case, we observed the phenomenon in terms of the spatial diffusion process and by observing the relation between the epidemic and various environmental elements. In particular, we started from a hypothesis of the comparable economic, geographical, climatic and environmental conditions of the areas of Wuhan (in the Hubei Province in China, where the epidemic broke out) and the Po Valley area (in Italy) where most cases and deaths were registered. Via an ecological approach, we compared the spatial distribution and pattern of COVID-19-related mortality in Italy with several geographical, environmental and socio-economic variables at a Provincial level, analyzing them by means of spatial analytical techniques such as LISA (Local Indicators of Spatial Association). Possible evidence arose relating to COVID-19 cases and Nitrogen-related pollutants and land take, particularly in the Po Valley area.

scholarly journals Non-Uniformity of the Combustor Exit Flow Temperature in Front of the Gas Turbine

2014 ◽  
Vol 8 (4) ◽  
pp. 209-213
Author(s):  
Józef Błachnio ◽  
Wojciech I. Pawlak
Keyword(s):  
Temperature Field ◽  
Gas Turbine ◽  
Gradual Increase ◽  
Turbine Blades ◽  
Static Properties ◽  
Flow Temperature ◽  
Jet Engine ◽  
Simulation Results ◽  
Object Of Control ◽  
Working Agent

Abstract Various types of damages to gas-turbine components, in particular to turbine blades, may occur in the course of gas turbine operation. The paper has been intended to discuss different forms of damages to the blades due to non-uniformity of the exit flow temperature. It has been shown that the overheating of blade material and thermal fatigue are the most common reasons for these damages. The paper presents results from numerical experiments with use of the computer model of the aero jet engine designed for simulations. The model has been purposefully modified to take account of the assumed non-homogeneity of the temperature field within the working agent at the turbine intake. It turned out that such non-homogeneity substantially affects dynamic and static properties of the engine considered as an object of control since it leads to a lag of the acceleration time and to increase in fuel consumption. The summarized simulation results demonstrate that the foregoing properties of a jet engine are subject to considerable deterioration in pace with gradual increase of the assumed non-homogeneity of the temperature field. The simulations made it possible to find out that variations of the temperature field nonhomogeneity within the working agent at the turbine intake lead to huge fluctuation of the turbine rpm for the idle run.

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