Assessment of blasting operations effects during highway tunnel construction

Blasting operations are one of the fundamental parts of daily civil engineering. Drilling and blasting still remain the only possible ways of tunnelling in very adverse geological conditions. However, this method is a source of various disadvantages, the main one being tremors propagating through the geological environment which not only affect buildings, but also disturb the comfort of living in the vicinity of the source. Designing this procedure is mostly done using standardized empirical relations. This article shows the possibility of using a FEM technique in predicting blast effects. This approach is demonstrated in a simple case study on the impact of blasting operations on steel pipes

Clays, clay minerals and cordierite ceramics - a review

The conventional methods for the synthesis of cordierite ceramics include the solid-state sintering of individual oxides of magnesium, aluminium and silicon of the corresponding chemical composition of cordierite, or sintering of the natural raw materials. Clays are used in the ceramics industries largely because of their contribution to the molding and drying properties. The most effective use of clays meets with the problems of the improvement of the working properties of clays and bodies through additions of non-plastic materials or chemicals and the influence of the clay content of ceramic bodies on their behavior during firing. Applicable nomenclatures for clays, clay minerals, ceramic raw materials, cordierite ceramics and characteristic structural properties of the cordierite and cordierite polymorphs are summarized. Selected published data confirmed the fact that identical formulation of clay mineral mixtures led to a variable mineral phases sintered in cordierite ceramics. Among the many factors, important roles play chemical and structural characteristics of individual clay minerals used in the clay mineral mixtures and methodology of processing of the green body and sintering conditions.Web of Science59434033

Structural characteristics of cordierites based on commercial vermiculites in relation to the natural and synthetic cordierites

The preparation and characterization of cordierites based on the commercial vermiculites obtained from the powder pre-ceramic mixtures containing talc, kaolinite and vermiculite in the composition close to the cordierite 2MgO.2Al(2)O(3).5SiO(2) has been reported since 2009. The aim of this paper was to characterize the structural properties of the nine synthetic cordierites sintered from the pre-ceramic mixtures containing commercial vermiculites at 1300 degrees C, in comparison with the orthorhombic natural and synthetic hexagonal cordierites (indialites) selected from literature. The orthorhombic natural cordierites showed the elements Fe and Mn replacing Mg in an appropriate correlation F = (Fe+Mn)/(Fe+Mn+Mg) with the unit cell parameter a, and an inverse correlation with parameter c. The unit cell parameters c calculated for the nine synthetic cordierites based on vermiculites (Ver) were in good linear relation with the F-ver = (Fe/(Fe+Mg)(oct) + (K+Na+Ca)(int)) per formula unit of the corresponding vermiculites in the pre-ceramic mixtures. The structural disorder of cordierites based on vermiculites was determined higher, according to the wide index W1/3 of (211) reflection varying in a narrow range W1/36((211)) from 0.290 degrees to 0.299 degrees 2 theta, in comparison with the W1/3((211))= 0.324 degrees 2 theta of the cordierites based on the alumina.Web of Science60431630

Family House

Obsahem bakalářské práce je návrh rodinného domu pro čtyřčlennou rodinu v Praze 6 na Hanspaulce. V okolí parcely je převážně zástavba rodinných domů o dvou až tří podlaží, v blízkosti parcely se nachází slavná vila Lídy Baarové a známá osada Baba s funkcionalistickými vilami z 30.let 20.století Cílem návrhu je vytvořit rodinný dům architektonické kvality s výhledem na Prahu a maximálního propojení interiéru s exteriérem formou velkoformátových oken a zelených teras. Bylo také dbáno na to, aby dům dispozične rodinnu co nejvíce stmeloval. Součástí dispozice je také návrh garsoniéry pro prarodiče s možností pronájmu v budoucnosti.The content of the bachelor thesis is to design a family house for family of four member in Prague 6 in Hanspaulka. The plot of land is located in the neighbourghood with mostly family houses of two and three floors, close to the parcel is famous Lída Baarová villa and famous village Baba with funkcionalism villas from 30´s of 20th century. The goal was to design architectural family house with the outlook on Prague and maximal connection between interior and exterior by using hufe-size of windows and green terraces. It was also important to design a house to keep family together for most of the time. In the house is also one-room flat for grandparents with possibily of renting it in the futur

α-Fe2O3 nanoparticles/vermiculite clay material: Structural, optical and photocatalytic properties

Photocatalysis is increasingly becoming a center of interest due to its wide use in environmental remediation. Hematite (-Fe2O3) is one promising candidate for photocatalytic applications. Clay materials as vermiculite (Ver) can be used as a carrier to accommodate and stabilize photocatalysts. Two different temperatures (500 degrees C and 700 degrees C) were used for preparation of -Fe2O3 nanoparticles/vermiculite clay materials. The experimental methods used for determination of structural, optical and photocatalytic properties were X-ray fluorescence (ED-XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), N-2 adsorption method (BET), diffuse reflectance UV-Vis spectroscopy (DRS), photoluminescence spectroscopy (PL) and photocatalytic reduction of CO2, respectively. The data from XRD were confronted with molecular modeling of the material arrangement in the interlayer space of vermiculite structure and the possibility of anchoring the -Fe2O3 nanoparticles to the surface and edge of vermiculite. Correlations between structural, textural, optical and electrical properties and photocatalytic activity have been studied in detail. The -Fe2O3 and -Fe2O3/Ver materials with higher specific surface areas, a smaller crystallite size and structural defects (oxygen vacancies) that a play crucial role in photocatalytic activity, were prepared at a lower calcination temperature of 500 degrees C.Web of Science1211art. no. 188

Vibrational spectroscopy of acid treated vermiculites

The natural vermiculites from different localities (Bulgaria, Brazil, and South Africa) after acid treatment were used for this study. Differently acidified vermiculite samples were prepared from the natural vermiculite sample using different concentrations of hydrochloric acid (0.5 M and 1 M) and different reaction time (2 h and 4 h) at 80 °C. Natural vermiculites and acid treated vermiculites were analyzed by elemental analysis, X-ray diffraction (XRD) analysis and studied using Fourier transform infrared (FTIR) spectroscopy and dispersive Raman spectroscopy. According to the XRD analysis vermiculites are interstratified structures created in the different two-one-zero sheet hydrated phases. Ratio of intensities of spectrally deconvoluted bands at 1075 cm−1 and 1000 cm−1 (stretching vibration of Sisingle bondO bonds of vermiculites and stretching vibration of Sisingle bondO bonds of amorphous silica, respectively) was used to determine the content of amorphous silica in acid treated vermiculite samples. Study of the infrared and Raman spectra of the acidified vermiculites enable a comparison of these two spectroscopic data that have not yet been performed.Web of Science70696

Basic generated universal fuzzy measures

AbstractThe concept of basic generated universal fuzzy measures is introduced. Special classes and properties of basic generated universal fuzzy measures are discussed, especially the additive, the symmetric and the maxitive case. Additive (symmetric) basic universal fuzzy measures are shown to correspond to the Yager quantifier-based approach to additive (symmetric) fuzzy measures. The corresponding fuzzy integral-based aggregation operators are introduced, including the generated OWA operators

Enforcement of Tax Arrears in the Czech Republic including their Security and Tax Execution

Import 22/07/2015Tato bakalářská práce se zaměřuje na problematiku vymáhání daňových nedoplatků v České republice včetně jejich zajištění a daňové exekuce. V práci jsou popsány základní zásady v oblasti správy daní a také vznik daňových nedoplatků včetně postupu správce daně při jejich zajištění a následného vymáhání. Poslední část se zabývá konkrétními způsoby vymáhání daňových nedoplatků na zvoleném finančním a na vybraných obecních úřadech v České republice.This bachelor’s thesis focuses on issue of enforcement of tax arrears in the Czech Republic including their security and tax execution. This bachelor’s thesis describes basic principles in the sphere of administration of taxes; also it describes the establishment of tax arrears including the steps of tax administrators leading to their security and tax execution. The last part of this thesis deals with the ways of enforcement of the tax arrears in chosen tax office and municipal authorities in the Czech Republic.117 - Katedra účetnictvívýborn