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Start Over Rights http://creativecommons.org/licenses/by-nc-sa/4.0/ Date Unknown

34952. Zhroucení budov Světového obchodního centra (WTC) z hlediska stavební mechaniky

Creator:
Bažant, Zdeněk P. and Jirásek, Milan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
stavební mechanika, structural mechanics, 6, and 53
Language:
Czech
Description:
The widely accepted cause of the collapse of the World Trade Center (WTC) towers in New York on Sept. 11, 2001, has been confirmed mathematically and firmly supported by mechanical analysis. Some lay critics, however, still question the conclusions of this analysis, even without presenting any meaningful calculations. They blame the collapse on a controlled demolition, implying a conspiracy by the republican government. many mass media outlets, including Czech ones, blindly gave this misinformation wide publicity. The present invited article summarizes why the collapse was a spontaneous and inevitable result of aircraft impact, and how this fact is explained and confirmed by mathematical analysis of the mechanics of collapse, and by numerous observed data., Zdeněk P. Bažant, Milan Jirásek., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34953. Žiarenie slnečnej chromosféry

Creator:
Koza, Július
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
sluneční záření, Slunce, spektroskopie, solar radiation, Sun, spectroscopy, 6, and 53
Language:
Czech and English
Description:
This contribution gives a brief description of the characteristics of spectral lines formed in the solar chromosphere in the visual range and its continuum in the visual, millimetre, and sub-millimetre (mm-submm) spectral range. The contribution reviews processes responsible for continuum radiation of the limb in the visual range and continua in the mm-submm spectral range. The spectral lines of sodium doublet Na I D1 and D2 are not genuine chromospheric lines since their cores are formed predominately by resonant scattering of radiation from the upper photosphere. Therefore, the cores of Na I D1 and D2 provide information only about chromospheric velocities. An occurrence of the doublet Na I D1, D2 together with helium lines with large excitation and ionization potential indicates an intricate thermodynamic structure of the chromosphere. As numerical simulations indicate, the chromospheric internetwork comprises of cooler cavities surrounded with hotter sheets allowing the occurrence of spectral lines over a large range of excitation and ionization potentials. The contribution accentuates the large diagnostic potential of the mm-submm continua of the chromospheric spectrum. It will be fully exploited after finishing of the ALMA array for the study of the chromospheric fine structure with large angular and temporal resolution., Príspevok podáva stručnú charakteristiku čiarového spektra slnečnej chromosféry vo vizuálnej oblasti a jej spojitého spektra (kontinua) vo vizuálnej, milimetrovej a submilimetrovej (mm-submm) oblasti. Príspevok predstavuje procesy tvoriace vizuálne kontinuum pozorovatel'né na limbe a kontinuá v mm-submm oblasti. Čiary sodíkového dubletu NA I D1 a D2 nie sú v pravom slova zmysle chromosférické, pretože ich jadrá sú tvorené hlavne rezonančným rozptylom žiarenia hornej fotosféry, a preto poskytujú informáciu iba o rýchlostných poliach v chromosfére. Výskyt dubletu Na I D1 a D2 spolu s čiarami hélia s veľkou excitačnou a ionizačnou energiou naznačuje zložitú termodynamickú štruktúru chromosféry. Ako ukazujú numerické simulácie, chromosféra sa v oblastiach mimo magnetickej siete skládá z chladnejších oblastí obalených horúcou látkou, čo umožňuje vznik spektrálnych čiar vo vel'kom rozsahu excitačných a ionizačných energií. Príspevok poukazuje na vel'ký diagnostický potenciál kontinuí v mm-submm oblasti spektra chromosféry, ktorý bude naplno využitý po dokončení rádioteleskopu ALMA pri štúdiu jemnej štruktúry chromosféry s vel'mi vel'kým uhlovým a časovým rozlíšením., Július Koza., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34954. Zíbrtův "Český lid" a moravští národopisci

Creator:
Altman, Karel and Křížová, Markéta
Format:
print
Type:
model:internalpart and TEXT
Language:
Czech
Description:
Cultural historian and ethnographer Čeněk Zíbrt, scientist, university professor and editor of popular periodicals, entered the awareness of his contemporaries as a prominent, erudite specialist. As such he had been accepted not only in Bohemia, but also in Moravia. To his fame contributed also his role of an editor of the ethnographic journal „Český lid“ [Czech Folk], published since the year 1892. Precisely for the Moravian ethnographes the contacts with this journal and with Zíbrt himself were of multilateral importance. They were sending him their publications, books and various treatises to be reviewed or propagated in Český lid. Themselves they also contributed to the journal with their articles, texts of varied quality and different genres, extensive studies, shorter articles and various bagatelles. An important contribution represented also the illustrations, sent from Moravia by artistically competent ethnographers and photographers. Český lid, on the other hand, offered a welcome source of income to many authors. However, Zíbrt selected carefully from the contributions sent by the ethnographers, so many of them waited long for the publication of their article. Many of the contributors asked their texts and illustrations to be returned to them, sometimes not successfully. Such inauspicious experiences with publicating in Český lid resulted in limitation of contacts of some ethnographers with Zíbrt. In špite of this, the majority of them appreciated the periodical very much. This fact was documented also by their not pretended joy from the renewal of Český lid in the 1920 ’s. Zíbrt, editor of the renewed journal, was contacted by new or renewed contributors.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34957. Židovské náboženské právo v právním systému Státu Izrael: koncept vázané ženy - "aguna"

Creator:
Sedláková, Dominika
Type:
article, články, model:article, and TEXT
Subject:
Sociologie kultury. Kulturní život, sociologie kultury, sociology of culture, 1, and 316.7
Language:
Czech
Description:
The marriage and divorce law of the State of Israel was influenced by Jewish religious law. The matter of agunot, „chained“ women, is an example of the usage of Jewish religious law in the legal system of the modern country. Aguna is a woman who is not able to remarry beacuse she has not been given a divorce list. The motive behind withholding a get is in most cases economic or other benefit. The matter of agunot is very old and Jewish scholars have tried to find a solution for many centuries. There are proposed solutions how to help women tobe released from marriage and to begin a new life. Some of them are very old and they are developer in many responses, others are new. All of them have the same aim to free women from a nonfunctional marriage by means which are contrary to Jewish religious law of marriage and divorce., Dominika Sedláková., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34960. Žijeme v době šestého masového vymírání?: Odhady rozsahu současných změn biodiverzity po deseti letech

Creator:
Storch, David
Type:
article, model:article, and TEXT
Language:
Czech
Description:
Do we live in the era of Earth´s sixth mass extinction? Estimates of current biodiversity changes. Current biodiversity crisis is often compared to the live mass extinction in geological history. Here I review the evidence concerning current global extinction, showing that its extent is so far much smaller than was in the case of the live big extinction events. However, global extinction rate is currently quite high, so that if the rate remains the same, the magnitude of the sixth global mass extinction could be reached within next several hundreds years. The topics are now much more vulnerable to animal and plant extinction than is the temperate zone.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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