The paper investigates ways to model the response of vibro-isolation mounts that utilise viscoelastic materials. Simple models based on linear and nonlinear static stiffness are developed. Dynamic response is approximated through appropriate scaling of the viscoelastic Young's modululs and use of the measured material loss factor. The approach is validated using cylindrical mounts made of polyurethane. The response of a 68 kg mass supported by two mounts and subjected to two different high-amplitude shock loads is predicted. Measured and predicted behaviour correlate closely for the nonlinear model while the linear model gives a reasonable representation. It is noted that the sensitivity of such mounts to temperature is high: the change in response associated with a temperature excursion of 10 °C is significantly greater than the inaccuracy involved with using the linear model. and Obsahuje seznam literatury
Různé přístupy к teoretickému popisu jazyka je třeba porovnávat jak co do empirického rozsahu popisného rámce, tak co do kvalit a stupně dodržování jejich principů. Důležité je diskutoval věcně o možnosti spojení jednotlivých dílčích řešení do bezrozporných celků a o možnostech, jak co nejekonomičtěji zachytit jádro (centrum) jazykového systému.
The concept of a semiprime ideal in a poset is introduced. Characterizations of semiprime ideals in a poset P as well as characterizations of a semiprime ideal to be prime in P are obtained in terms of meet-irreducible elements of the lattice of ideals of P and in terms of maximality of ideals. Also, prime ideals in a poset are characterized.
Studie navazuje na předchozí autočino zkoumání české literaturu z hlediska hodnot, které se v ní odrážejí (viz Seimotic Odyssey through Czech Literature, 1997). V předkládáné studii srovnává přístup ke smrti v některých závažných dílech české literatury jak 19. a 20. století. Nejdříve srovnává pojetí smrti v Máchově Máji a Němcové Babičce a dospívá k závěru, že Němcová neprojevuje strach ze smrti jako Mácha, ale podvědomě odráží určité trauma, charakteristické pro tehdejší společnost a toto vlastní trauma projektuje do postavy vyvrženkyně Viktorky. Následně upozorňuje na neočekávanou podobnost mezi Máchou a Němcovou, a to v ohledu vztahu mezi smrtí a sexualitou. Jak Máchův hrdina, tak Viktorka hynou násilně na následky pomýleného sexuálního vztahu, podvedeni svým partnerem. Smrt je tak přímo usouvztažněna k nepřítomnosti lásky. Jediný rozdíl je v tom, že Mácha je v tomto ohledu k roli společnosti kritický, kdežto Němcová ji pasivně přijímá. V další části studie je analyzováno pojetí smrti v Nerudových Povídkách malostranských. Autorka konstatuje, že smrt je u Nerudy běžná, každodenní záležitost provázená většinou lhostejností bližních a někdy způsobená i jejich krutostí. Nemá skrytou symbolickou hodnotu jako u Máchy či Němcové. Autor prezentuje smrt jako vnější realistický pozorovatel. Závěrečná část analyzuje pojetí smrti u Bohumila Hrabala a Milana Kundery. Celkově pak dospívá k závěru, že přístup ke smrti je podmíněn jak individuální a dobovou poetikou, tak společenským systémem hodnot charakteristickým pro jistou lokalitu, dobu a společenskou vrstvu, tak osobním přístupem a zkušeností, ba i fyzickým věkem autora. Autorka upozorňuje, že když mluvíme o smrti jako sémiotické události, nevyhneme se nikdy otázce sémiotiky vypravěčova života. and This article further develops the author’s previous investigations of Czechliterature from the point of view of the values reflected in it, see for example,her Semiotic Odyssey through Czech Literature (1997). It compares theapproach to death in some important Czech works from the nineteenth andtwentieth centuries. First, she compares the conception of death in KarelHynek Mácha’s Máj (1836) and Němcová’s Babička (1855) and comes to theconclusion that although Němcová does not express fear of death like Máchadoes, she subconsciously reflects a certain trauma, characteristic of society ofthe time and projects that trauma into the character Viktorka, the outcast.She then points out the unexpected similarity between Mácha and Němcováin the relationship between death and sexuality. Both Mácha’s hero andNěmcová’s Viktorka meet violent deaths in consequence of a mistaken sexualrelationship, cheated by their lovers. Death is thus directly related to the absence of love. The only difference is that Mácha is in this respect critical ofthe role of society, whereas Němcová passively accepts it.The next part of the article analyzes the conception of death in Jan Neruda’sPovídky malostranské (1878). It argues that here death is a regular everydaymatter, usually accompanied by the indifference of the deceased’s neighboursand kin and sometimes even caused by their cruelty. It has no concealedsymbolic value as it does, by contrast, in Mácha and Němcová. Nerudapresents death as a realistic external observer.The last part analyzes the conception of death in works by Bohumil Hrabaland Milan Kundera and distinguishes between innovative values incorporatedinto different works by these two authors and values passively accepted fromthe society’s code of the time. On the whole the author concludes that theapproach to death is contingent on individual and period styles and socialvalues characteristic of a particular area, time, and social strata, as well as onpersonal approach and experience, indeed even on the age of the authors atthe time they were writing. The article points out that contemplating death asa semiotic event mandates consideration of the semiotics of the narrator’s life.
The territory of the Polar Urals is characterized by significant forecast resources of natural zeolites. In case of their successful development, the resources of the zeolite deposits can provide a positive impact on the development of a number of industries in the adjacent regions of the Urals and Western Siberia. At the same time, the available data about the zeolite-bearing rocks of the Polar Urals present in published research paper and materials of geological funds is rather contradictory. The results of research performed by different scientific groups often contain opposed conclusions on the mineralogical composition, the content of the commercial component in the ore, as well as on the ore reserves calculation and the potential of commercial exploitation for the same mineral occurrences. In many respects, this situation can be explained by the complexity of the geological and geomorphological conditions of the territory under consideration, the remoteness of the promising mineral occurrences from large scientific and industrial centers, and the variety of ore occurrences. This work presents the study results of lithological–petrographic features and the material composition of the eluvial debris of the Middle–Late (Givetian–Frasnian) Devonian zeolite-bearing rocks of the volcanogenic-sedimentary origin within the Naunpe area of the Polar Urals., The main objective of the proposed research was to evaluate the economic feasibility of their development and possible directions for commercial exploitation of this type of ores. Research methods included petrographic study of samples of zeolite-bearing rocks in thin sections, SEM-EDS, determination of the total mineral composition by XRD and the chemical composition by XRF. Within the Naunpe area, the outcrops of zeolite-bearing rocks on the surface are represented by blankets and debris of small lumpy–gravel eluvial deposits with indistinct outlines. Macroscopically, zeolite-bearing eluvial deposits are represented by reddish or pinkish in color, massive and relatively homogenous rocks. The ore occurrences are well interpreted based on the remote sensing data. According to the results of petrographic, lithological, and mineralogical studies, three main rock types were distinguished among the eluvial debris deposits: zeolite-bearing crystallo–lithoclastic tuffs of the mafic, intermediate, and felsic composition, and also tuffoargillites, and siliceous rocks., and Crystallo–lithoclastic tuffs and tuffoargillites contain Ca-zeolites, represented mainly by laumontite (13.8–18.9 %), which fill small open spaces between crystallites and lithoclasts. Volcanic glass fragments and feldspars from tuffoargillites are replaced partially or completely by zeolites. The content of zeolites in these rocks is even lower (less than 10 %). The characteristic features of the studied zeolite-bearing rocks from the ores of the known deposits of the Polar and Subpolar Urals have higher contents of Fe2O3, CaO и Na2O and lower content of K2O. The obtained results show that the studied rocks are quite complex, diverse, and polygenetic, as well as their formation is a result of several stages of post-volcanic authigenic mineral formation. The rather low content of zeolite minerals in these rocks and high variability of the material composition decrease the industrial potential of that eluvial debris deposits as an object of mineral raw material base. At this, they can be considered as prospecting indicator for prospecting the areas with a similar geological structure.