scholarly journals Impact of second trip echoes for space-borne high PRF nadir-looking W-band cloud radars

2021 ◽  
Author(s):  
Alessandro Battaglia
Keyword(s):  
Multiple Scattering ◽  
W Band ◽  
Future Space ◽  
Sampling Window ◽  
Mechanisms Of Formation ◽  
The Moment ◽  
The One ◽  
The Tropics ◽  
Level 2 ◽  
Upper Boundary

Abstract. The appearance of second trip echoes generated by mirror images over the ocean and by multiple scattering tails in correspondence of deep convective cores has been investigated for space-borne nadir-looking W-band cloud radar observations. Examples extracted from the CloudSat radar are used to demonstrate the mechanisms of formation and to validate the modeling of such returns. A statistical analysis shows that, for CloudSat observations, second trip echoes are rare and appear only above 20 km (thus easy to remove). CloudSat climatology is then used to estimate the occurrence of second trip echoes in the different configurations envisaged for the operations of the EarthCARE radar, which will adopt pulse repetition frequencies much higher than the one used by the CloudSat radar in order to improve its Doppler capabilities. Our findings predict that the presence of such echoes in EarthCARE observations cannot be neglected: in particular, over the ocean, mirror images will tend to populate the EarthCARE sampling window with a maximum frequency at its upper boundary. This will create an additional fake cloud cover in the upper troposphere (of the order of 3 % at the top of the sampling window and steadily decreasing moving downwards) and, in much less frequent instances, it will cause an amplification of signals in areas where clouds are already present. Multiple scattering tails will produce also second trip echoes but with much lower frequencies: less than one profile out of 1000 in the Tropics and practically no effects at high latitudes. At the moment Level-2 algorithms of the EarthCARE radar do not account for such occurrences. We recommend to properly remove these second trip echoes and to correct for reflectivity enhancements, where needed. More generally this work is relevant for the design of future space-borne Doppler W-band radar missions.

scholarly journals Impact of second-trip echoes for space-borne high-pulse-repetition-frequency nadir-looking W-band cloud radars

2021 ◽  
Vol 14 (12) ◽  
pp. 7809-7820
Author(s):  
Alessandro Battaglia
Keyword(s):  
Multiple Scattering ◽  
Pulse Repetition Frequency ◽  
Pulse Repetition ◽  
W Band ◽  
Sampling Window ◽  
Mechanisms Of Formation ◽  
High Pulse ◽  
The Moment ◽  
The One ◽  
The Tropics

Abstract. The appearance of second-trip echoes generated by mirror images over the ocean and by multiple scattering tails in correspondence with deep convective cores has been investigated for space-borne nadir-looking W-band cloud radar observations. Examples extracted from the CloudSat radar are used to demonstrate the mechanisms of formation and to validate the modelling of such returns. A statistical analysis shows that, for CloudSat observations, second-trip echoes are rare and appear only above 20 km (thus easy to remove). CloudSat climatology is then used to estimate the occurrence of second-trip echoes in the different configurations envisaged for the operations of the EarthCARE radar, which will adopt pulse repetition frequencies much higher than the one used by the CloudSat radar in order to improve its Doppler capabilities. Our findings predict that the presence of such echoes in EarthCARE observations cannot be neglected: in particular, over the ocean, mirror images will tend to populate the EarthCARE sampling window with a maximum frequency at its upper boundary. This will create an additional fake cloud cover in the upper troposphere (of the order of 3 % at the top of the sampling window and steadily decreasing moving downwards), and, in much less frequent instances, it will cause an amplification of signals in areas where clouds are already present. Multiple scattering tails will also produce second-trip echoes but with much lower frequencies: less than 1 profile out of 1000 in the tropics and practically no effects at high latitudes. At the moment, level-2 algorithms of the EarthCARE radar do not account for such occurrences. We recommend to properly remove these second-trip echoes and to correct for reflectivity enhancements, where needed. More generally this work is relevant for the design of future space-borne Doppler W-band radar missions.

The Munich conference of Minister-Presidents of German lands in 1947

2020 ◽  
Vol 2020 (10-2) ◽  
pp. 86-98
Author(s):  
Ivan Popov
Keyword(s):  
The State ◽  
State Governments ◽  
The West ◽  
Constitutional Development ◽  
The Moment ◽  
The One

The paper deals with the organization and decisions of the conference of the Minister-Presidents of German lands in Munich on June 6-7, 1947, which became the one and only meeting of the heads of the state governments of the western and eastern occupation zones before the division of Germany. The conference was the first experience of national positioning of the regional elite and clearly demonstrated that by the middle of 1947, not only between the allies, but also among German politicians, the incompatibility of perspectives of further constitutional development was existent and all the basic conditions for the division of Germany became ripe. Munich was the last significant demonstration of this disunity and the moment of the final turn towards the three-zone orientation of the West German elite.

scholarly journals Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton
Keyword(s):  
Main Sequence ◽  
Open Clusters ◽  
Main Sequence Stars ◽  
Spectroscopic Analyses ◽  
Solar Metallicity ◽  
Metal Abundances ◽  
The Mean ◽  
The Moment ◽  
The One ◽  
Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

L'etica nella professione forense

2009 ◽  
pp. 163-172
Author(s):  
Angelo Abignente
Keyword(s):  
Public Interests ◽  
Legal Proceedings ◽  
Legal Professionals ◽  
Positive Law ◽  
Conflicting Interests ◽  
Discursive Participation ◽  
The Moment ◽  
The One ◽  
And Function ◽  
Role And Function

- The positive law tradition has hitherto had nothing to say about the legal profession's role and function, focusing more interest on questions of justice, of the legitimisation of power and of the genesis and organisation of normative material. This trend is now subject to a reversal promoted by new, neo-constitutionalist, narrativist, analytical and hermeneutic experiences, which no longer focuses attention on the moment when law is produced, but on the one when it is applied, reappraising and revitalising the function of the judge, of the attorneys and of other legal professionals. The attorney becomes an active protagonist, an intermediary not only between conflicting interests in a controversy, but also between opposing public interests, while the reappraisal of his role stimulates thinking about the ethical dimension of how the legal profession is practised. Referring to the theories of Habermas and of Alexy, the author treats the reasonable status of argumentation as the supreme ethical instance necessary for a decision that interferes in the sphere of another person's action. At the same time, however, the control of the reasonable status of the respective arguments on both sides is the ethical instance required of the attorneys taking part in the legal proceedings. It takes the form of compliance with the rules characteristic of the practical discourse, primarily the rule of free discursive participation that enables the onus of the argumentation to be explained. Ernesto de

“In the Moment I Wanted to Kill Myself, and Then After I Didn’t”: A Qualitative Investigation of Suicide Planning, Method Choice, and Method Substitution Among Adolescents Hospitalized Following a Suicide Attempt

2021 ◽  
pp. 0044118X2110359
Author(s):  
Joanna Almeida ◽  
Catherine Barber ◽  
Rochelle K. Rosen ◽  
Alexandra Nicolopoulos ◽  
Kimberly H. McManama O’Brien
Keyword(s):  
Suicide Attempt ◽  
Suicide Attempts ◽  
Planning Method ◽  
Easy Access ◽  
Future Research ◽  
Method Choice ◽  
The Moment ◽  
The One ◽  
Suicide Planning ◽  
Method Substitution

Research on planning, method choice, and method substitution in adolescents’ suicide attempts is limited. We conducted in-depth interviews with 20 adolescents following their suicide attempt to learn the extent to which the attempt was planned, why they used the method they did, and whether they would have substituted another method if the one they used had been unavailable. Applied Thematic Analysis was used to identify codes and develop themes. Attempts were largely unplanned, and planned attempts were often haphazard, as urgency to escape immediate pain was a main impetus for the attempt. Method choice was driven by easy access. Half of participants said they would not have attempted suicide if the method they used were inaccessible, but 7 of 20 said they would have, and 3 were unsure. Not all suicide attempts would be prevented by blocking access to methods that adolescent attempters would otherwise use. To understand whether restricting access to low-lethality methods could harm some attempters, future research should examine in-the-moment method substitution.

Der Fall des Philosophen

2019 ◽  
Author(s):  
Hanna Gekle
Keyword(s):  
20Th Century ◽  
Oedipus Complex ◽  
The Other ◽  
Philosophical Theory ◽  
Ernst Bloch ◽  
The Uncanny ◽  
History Of ◽  
Painful Experience ◽  
The Moment ◽  
The One

The history of mental development on the one and the history of his writings on the other hand form the two separate but essentially intertwined strands of an archeology of Ernst Bloch´s thought undertaken in this book. Bloch as a philosopher is peculiar in that his initial access to thought rose from the depths of early, painful experience. To give expression to this experience, he not only needed to develop new categories, but first and foremost had to find words for it: the experience of the uncanny and the abysmal, of which he tells in Spuren, is on the level of philosophical theory juxtaposed by the “Dunkel des gerade gelebten Augenblicks” (darkness of the moment just lived) and his discovery of a “Noch-nicht-Bewusstes” (not-yet-conscious), thus metaphysically undermining the classical Oedipus complex in the succession of Freud. In this book, psyche, work and the history of the 20th century appear concentrated in Ernst Bloch the philosopher and contemporary witness, who paid tribute to these supra-individual powers in his work as much as he hoped to transgress them.

scholarly journals Predictive anatomical factors for rupture in middle cerebral artery mirror bifurcation aneurysms

2018 ◽  
Vol 128 (6) ◽  
pp. 1799-1807 ◽  
Author(s):  
Homajoun Maslehaty ◽  
Crescenzo Capone ◽  
Roman Frantsev ◽  
Igor Fischer ◽  
Ramazan Jabbarli ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Internal Carotid ◽  
Rupture Risk ◽  
Significance Level ◽  
Ruptured Aneurysms ◽  
Regular Shape ◽  
The Moment ◽  
The One ◽  
Aneurysm Shape

OBJECTIVEThe aim of this study was to define predictive factors for rupture of middle cerebral artery (MCA) mirror bifurcation aneurysms.METHODSThe authors retrospectively analyzed the data in patients with ruptured MCA bifurcation aneurysms with simultaneous presence of an unruptured MCA bifurcation mirror aneurysm treated in two neurosurgical centers. The following parameters were measured and analyzed with the statistical software R: neck, dome, and width of both MCA aneurysms—including neck/dome and width/neck ratios, shape of the aneurysms (regular vs irregular), inflow angle of both MCA aneurysms, and the diameters of the bilateral A1 and M1 segments and the frontal and temporal M2 trunks, as well as the bilateral diameter of the internal carotid artery (ICA).RESULTSThe authors analyzed the data of 44 patients (15 male and 29 female, mean age 50.1 years). Starting from the usual significance level of 0.05, the Sidak-corrected significance level is 0.0039. The diameter of the measured vessels was statistically not significant, nor was the inflow angle. The size of the dome was highly significant (p = 0.0000069). The size of the neck (p = 0.0047940) and the width of the aneurysms (p = 0.0056902) were slightly nonsignificant at the stated significance level of 0.0039. The shape of the aneurysms was bilaterally identical in 22 cases (50%). In cases of asymmetrical presentation of the aneurysm shape, 19 (86.4%) ruptured aneurysms were irregular and 3 (13.6%) had a regular shape (p = 0.001).CONCLUSIONSIn this study the authors show that the extraaneurysmal flow dynamics in mirror aneurysms are nonsignificant, and the aneurysmal geometry also does not seem to play a role as a predictor for rupture. The only predictors for rupture were size and shape of the aneurysms. It seems as though under the same conditions, one of the two aneurysms suffers changes in its wall and starts growing in a more or less stochastic manner. Newer imaging methods should enable practitioners to see which aneurysm has an unstable wall, to predict the rupture risk. At the moment one can only conclude that in cases of MCA mirror aneurysms the larger one, with or without shape irregularities, is the unstable aneurysm and that this is the one that needs to be treated.

scholarly journals An Empire of Memory: Overseas British War Cemeteries, 1917–1983

2018 ◽  
Vol 38 (2) ◽  
pp. 255-286
Author(s):  
Sam Edwards
Keyword(s):  
Twentieth Century ◽  
South Atlantic ◽  
British Government ◽  
The South ◽  
Informal Empire ◽  
The Moment ◽  
The One

This article examines how a post-1918 Edwardian commemorative aesthetic focused on the “English Garden” was deployed in the later twentieth century as a means to establish an “informal” Empire of memory. The result is an architectural irony and a landscape at odds with the moment that made it: the post-1945 cemeteries of the Imperial War Graves Commission (IWGC) expanded the now defunct Empire’s commemorative possessions just as the actual deeds to land were surrendered. The one exception to this story of contemporaneous political withdrawal and commemorative appropriation nonetheless proves the broader point. For after the bloody imperial war fought in the South Atlantic in 1982 the Commission, at the behest of the British government, built its first and last post-1945 overseas war cemetery. And just as had been the case sixty years earlier, the form and style of this cemetery ensured it became the last outpost of an Edwardian Empire of memory.

A distributional theory for asymptotic expansions

1990 ◽  
Vol 428 (1875) ◽  
pp. 399-430 ◽  
Keyword(s):  
Asymptotic Expansions ◽  
Asymptotic Series ◽  
Generalized Functions ◽  
The Moment ◽  
The One ◽  
Topological Tensor Products ◽  
Multidimensional Integrals ◽  
Vector Valued ◽  
Selection Of ◽  
Mathematics And Physics

We present various techniques for the asymptotic expansions of generalized functions. We show that the moment asymptotic expansions hold for a very wide variety of kernels such as generalized functions of rapid decay and rapid oscillations. We do not use Mellin transform techniques as done by previous authors in the field. Instead, we introduce a direct approach that not only solves the one-dimensional problems but also applies to various multidimensional integrals and oscillatory kernels as well. This approach also helps in the development of various asymptotic series arising in diverse fields of mathematics and physics. We find that the asymptotic expansions of generalized functions depend on the selection of suitable spaces of test functions. Accordingly, we have exercised special care in classifying the spaces and the distributions defined on them. Furthermore, we use the theory of topological tensor products to obtain the expansions of vector-valued distributions. We present several examples to illustrate that many classical results follow in a simple manner. For instance, we derive from our results the asymptotic expansions of certain series considered by Ramanujan.

scholarly journals GOMOS ozone profile validation using ground-based and balloon sonde measurements

2010 ◽  
Vol 10 (21) ◽  
pp. 10473-10488 ◽  
Author(s):  
J. A. E. van Gijsel ◽  
D. P. J. Swart ◽  
J.-L. Baray ◽  
H. Bencherif ◽  
H. Claude ◽  
...  
Keyword(s):  
Selection Criteria ◽  
Polar Region ◽  
Temporal Trend ◽  
Microwave Radiometer ◽  
Line Of Sight ◽  
Night Time ◽  
Latitudinal Dependence ◽  
Ozone Profile ◽  
The Tropics ◽  
Level 2

Abstract. The validation of ozone profiles retrieved by satellite instruments through comparison with data from ground-based instruments is important to monitor the evolution of the satellite instrument, to assist algorithm development and to allow multi-mission trend analyses. In this study we compare ozone profiles derived from GOMOS night-time observations with measurements from lidar, microwave radiometer and balloon sonde. Collocated pairs are analysed for dependence on several geophysical and instrument observational parameters. Validation results are presented for the operational ESA level 2 data (GOMOS version 5.00) obtained during nearly seven years of observations and a comparison using a smaller dataset from the previous processor (version 4.02) is also included. The profiles obtained from dark limb measurements (solar zenith angle >107°) when the provided processing flag is properly considered match the ground-based measurements within ±2 percent over the altitude range 20 to 40 km. Outside this range, the pairs start to deviate more and there is a latitudinal dependence: in the polar region where there is a higher amount of straylight contamination, differences start to occur lower in the mesosphere than in the tropics, whereas for the lower part of the stratosphere the opposite happens: the profiles in the tropics reach less far down as the signal reduces faster because of the higher altitude at which the maximum ozone concentration is found compared to the mid and polar latitudes. Also the bias is shifting from mostly negative in the polar region to more positive in the tropics Profiles measured under "twilight" conditions are often matching the ground-based measurements very well, but care has to be taken in all cases when dealing with "straylight" contaminated profiles. For the selection criteria applied here (data within 800 km, 3 degrees in equivalent latitude, 20 h (5 h above 50 km) and a relative ozone error in the GOMOS data of 20% or less), no dependence was found on stellar magnitude, star temperature, nor the azimuth angle of the line of sight. No evidence of a temporal trend was seen either in the bias or frequency of outliers, but a comparison applying less strict data selection criteria might show differently.

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