Proposition of stiffness reduction in analysis of clay brick masonry under cyclic/seismic loads

Analysis of masonry buildings situated on seismic or mining activity terrains as well as subjected to dynamic human-induced vibrations and influences should base on the appropriated mechanical properties of masonry. There main parameters describing bending and shear stiffness’s of masonry shear walls are modulus of elasticity as well as shear modulus. Values of these parameters under seismic or cyclic loading are rapidly coming down due to the inelastic behaviour of the masonry. The problem of degradation of modulus of elasticity E as well as shear modulus G is presented and discussed based on the tests results of three types of clay brick masonry wall specimens subjected to compressive cyclic loads and some specimens under cyclic horizontally and vertical shearing (in one cycle) carried out at the Department of Structural Engineering of the Silesian University of Technology in Gliwice as well as results obtained by other researchers and available at the technical publications. As result there is proposed to determine the value of modulus of elasticity as 40 % of calculated with accordance with Eurocode 6 [1]. In case of shear modulus it is suggested to determine the G values as 20 % of initial values of modulus of elasticity, that is mean 50 % less than recommended in current version of Eurocode 6 [1] and perfectly correct with requirements given in Eurocode 8 [2]

Natural Text Processing and its Categorization

Zaměřením této práce byla problematika zpracovávání textu v přirozeném jazyce a jeho kategorizace. Konkrétním cílem bylo vyvinout program pro zpracování textů v češtině a angličtině a jejich následnou analýzu. Po zvážení výběru jazyka pro implementaci byl vybrán programovací jazyk Python a pro extrakci dat z internetu byla využita jeho knihovna Scrapy. Lemmatizace textů je realizována skrze knihovnu Majka. Program umí, po naučení z dodaných datasetů, porovnat několik možných algoritmů pro kategorizaci textu a nové data do daných kategorií zařadit. V programu je také implementováno shlukování textů pro kategorizaci bez počátečních datasetů.The aim of this work was the issue of text processing in natural language and its categorization, and specifically to develop a program for processing texts in Czech and English and their subsequent analysis. After considering the choice of language for implementation was selected programming language Python and its Scrapy library was used to extract data from the Internet. Lemmatization of texts is realized through its library Majka. The program can, after learning from the supplied datasets, compare several possible algorithms for text categorization and include new data in the given categories. The program also implements grouping of texts for categorization without initial datasets.460 - Katedra informatikyvýborn

Determination of bond model for 7-wire strands in pretensioned concrete beam

A correct choice of a bond model for prestressing tendons is crucial for the right modelling of a structural behaviour of a pretensioned concrete structure. The aim of this paper is the determination of an optimal bond model for 7-wire strands in a prestressed concrete beam produced in a precast concrete plant of Consolis Poland. ATENA 3D is used to develop finite element models of the beam that differ only in a bond stress-slip relationship of tendons. The bond stress-slip relationships for modelling are taken from the results of bond tests carried out by different researchers in previous years. Moreover, for comparison purposes, a simplified 2D model of the beam is created in Autodesk Robot. The strain distribution at the time of the strand release is found for each of the finite element models. The determined strain distributions are compared with the strain distribution in the beam established by an experimental test using a measuring system based on a digital image correlation. On the basis of the comparison results, the most appropriate bond models for 7-wire strands used in the beam are identified

Stress–strain characteristics of brick masonry under compressive cyclic loading

This paper presents the results of laboratory experiments carried out on twelve clay brick masonry wallettes of two types under cyclic compressive loading. In the paper, the procedure adapted for testing is described and the results are discussed. The failure models and cracking patterns of the tested specimens are presented. The effects of the repeated load on the behaviour and mechanical properties of the wall are observed and discussed. Based on the results, the analytical formula for the determination of the failure envelope curve is also proposed

Behaviour of unreinforced and reinforced masonry wallettes made of ACC blocks subjected to diagonal compresion

Od ponad 10 lat elementy wykonane z autoklawizowanego betonu komórkowego są jednym z najbardziej popularnych materiałów stosowanych do wznoszenia budynków mieszkalnych zarówno w Polsce, jak i Europie. Zalecana technologia wykonywania konstrukcji z takich materiałów wymaga stosowania cienkich spoin wspornych i niewypełnionych spoin czołowych. Niestety konstrukcje wznoszone w tej technologii są podatne na zarysowania. Jedną z metod ograniczania zarysowań jest wprowadzenie do spoin wspornych prefabrykowanego zbrojenia. Głównym celem prezentowanych badań jest analiza zachowania się muru niezbrojonego oraz zbrojonego zbrojeniem typu MURFOR®. Badane elementy poddano ukośnemu ściskaniu. Przebadano trzy grupy elementów próbnych, różniące się sposobem otulenia zbrojenia zaprawą. W trakcie analizy zwrócono szczególną uwagę na główny technologiczny problem, dotyczący zapewnienia prawidłowej przyczepności zbrojenia do elementu murowego

The reliability of noninvasive cardiac output measurement using the inert gas rebreathing method in patients with advanced heart failure

Background: Impaired cardiac output (CO) is a key element of heart failure (HF). So far, there has been no simple, reliable, inexpensive and non-invasive CO measurement method feasible for clinical practice. Not a single diagnostic test has been elaborated to diagnose and monitor HF. The aim of the study was the evaluation of the reliability of a new, non-invasive CO measurement device utilizing an inert gas rebreathing technique and an infrared photoacoustic gas analyzer, in comparison with standard invasive methods. Methods: In 21 patients with advanced HF (NYHA classes III and IV) undergoing cardiac catheterization as a routine hemodynamic evaluation before heart transplantation, CO measurements with the tested non-invasive method were carried out during invasive examination. Results: CO measured by the inert gas rebreathing technique (CORB), according to the statistical Bland-Altman method, was, on average, 0.1 L/min higher than that determined by thermodilution (COTD) and 0.006 L/min higher than the CO determined by the Fick formula (COFick). This magnitude of difference equals 2.8% of COTD and 0.15% of COFick values. The limits of agreement between CORB and COTD were ± 1.4 L/min, and between CORB and COFick ± 1.3 L/min. In the subgroup with atrial fibrillation, the mean difference between tested and reference methods (0.3 ± 1.0 L/min for both COTD and COFick) was higher than in the sinus rhythm subgroup (0.06 ± 1.5 L/min for COTD and 0.08 ± 1.5 for COFick). Conclusions: CO measurement with the inert gas rebreathing method utilizing an infrared photoacoustic gas analyzer seems reliable enough to be employed in clinical practice. Being non-invasive, it may well be used for repeated determinations in patients with HF. (Cardiol J 2008; 15: 63-70

Structural Analysis of Slender Glass Panel Subjected to Static and Impact Loading

Slender glass panels are widely used as storefronts and indoor separating walls in shopping malls and public buildings. To ensure that the design and construction is technically safe for general use and that it meets current and accepted technical standards, in-situ testing is required by the building administrator or authorities. A case study was performed of an indoor glass lantern in a public building made from slender two-side supported glass panels with a complex geometry. It provides structural assessments and results of in-situ experiments including static loading and soft body impact test. Results from numerical simulations of impact loading on the glass panels complementing the experimental results are also presented. The in-situ testing proved that the structural design meets current standards regarding the static loading. The soft body impact test proved the safety of the intact panel and the panel with one ply deliberately broken. The numerical study showed that, for a more complicated geometry, the stress distribution can dramatically change over time and that stress concentrations can develop at certain locations at a late stage in the impact history

Specific traits of Islamic law in relation to economic and financial systems

Islamic law is a legal system with a number of specific traits, which determine the path to the Islamic economic system. The Islamic banking system has been overlooked as an alternative to our financial system for years. The lack of interest to which it was exposed in the past clearly left a trace of misconceptions, with which we are accustomed to view it. It does not just concern the concept of our Western world banking in an Islamic environment. It is a system based on pillars, which are based on a very different historical context. The goal of the paper is to describe and explain the principles of the Islamic laws and the actual behaviour of the economy, as well as the economic entities formally operating under Islamic principles (mainly banks). Based on an understanding of the principles of Islamic law and the principles on which Islamic banks work and on an explanation of the banks’ main characteristics, in particular the relationship with interest, loan usury and clarification of the method of profit gain, the paper aims to evaluate the effect of Islamic finance and outline the current practice in the light of compliance with the fundamentals of Islamic financial law

Evaluation of thrombinogenesis in vivo in acute myocardial infarction in relation to concentrations of thrombin-antithrombin III complexes and antithrombin III activity

Background: Thrombotic processes play an essential role in the progression of the atheromatosis and pathogenesis of acute coronary syndromes. The role of haemostatic factors in the development of circulatory system diseases, ischaemic heart disease in particular, has met with great research interest. The purpose of the present research is to define the role of haemostatic factors in the pathogenesis of atheromatosis and ischaemic heart disease and also to deal with their impact on diagnosis and prognosis. The aim of the present study was to evaluate thrombin generation in vivo and to define the role of the main inhibitor of coagulation in patients with acute myocardial infarction. Methods: The study was performed using a group of 70 patients with acute myocardial infarction with ST segment elevation (STEMI). The control group comprised 25 healthy subjects matched for age and gender. Concentrations of thrombin-antithrombin III complexes (TAT complexes) and antithrombin III (AT III) activity were measured; the sample was taken before essential treatment was administered. Results: In a group of patients with myocardial infarction, significantly higher average concentrations of TAT complexes (p < 0.0001) and AT III activity (p < 0.001) were found. An inverse correlation between AT III activity and kinase phosphocreatine concentration (p < 0.02) was shown as well as a positive correlation between AT III activity and the time elapsing from the onset of infarction symptoms to admission (p < 0.05). The increase in TAT complex concentration and AT III activity did not depend on sex, age and risk factors for ischaemic heart disease, nor did it predict late complications.Conclusions: The results provide evidence of an intensification of thrombinogenesis processes in patients with acute myocardial infarction. The increase of AT III activity may reflect a compensatory mechanism of the haemostatic system with regard to intensified thrombinogenesis

Epidemia niewydolności serca - problem zdrowotny i społeczny starzejących się społeczeństw Polski i Europy

Niewydolność serca (HF) jest zespołem klinicznym będącym końcowym wspólnym etapem wielu chorób sercowo-naczyniowych. Mimo znacznych postępów w zrozumieniu patofizjologii, wdrożenia szeroko zakrojonej profilaktyki i wprowadzenia do leczenia nowoczesnych metod terapeutycznych, zarówno zachowawczych, jak i zabiegowych, HF stanowi coraz większy problem zdrowotny i społeczny w Europie. Obecnie jest ona jedyną jednostką chorobową układu sercowo-naczyniowego o wciąż wzrastającej częstości, a ponadto najczęstszą i najbardziej kosztowną przyczyną hospitalizacji pacjentów powyżej 65. roku życia, którzy są obarczeni największą śmiertelnością. W ostatnich latach istotny postęp w dziedzinie leczenia farmakologicznego i chirurgicznego wpłynął na znaczące wydłużenie życia, a w konsekwencji na proporcjonalny wzrost liczby chorych z przewlekłą niewydolnością serca, która występuje głównie u osób starszych. Obecnie najczęstszymi przyczynami HF w Polsce i Europie są choroba niedokrwienna serca i nadciśnienie tętnicze. W badaniach epidemiologicznych w celu rozpoznania HF najczęściej wykorzystuje się objawy kliniczne oraz wartość frakcji wyrzutowej (EF), które dotyczą głównie skurczowej HF. Nie istnieją jeszcze wiarygodne informacje na temat rozkurczowej dysfunkcji lewej komory. Niewydolność serca jest jednostką chorobową o bardzo złym rokowaniu, zwłaszcza w sytuacjach, gdy nie można zastosować leczenia przyczynowego. Wskaźniki 5-letniego przeżycia w przypadku HF są gorsze od wskaźników przeżycia osób z chorobami nowotworowymi (z wyjątkiem raka płuc), gdyż w zaawansowanej HF (IV klasa wg NYHA) około 50% chorych umiera w ciągu jednego roku. Koszty leczenia pacjentów z HF, nie wliczając wydatków związanych z transplantacją serca, ciągle wzrastają i obecnie wynoszą 1,5-2,5% wszystkich wydatków na służbę zdrowia. Niewydolność serca stanowi istotny problem zdrowotny i społeczny, a koszty leczenia tej grupy pacjentów będą stale wzrastały. W Polsce są to wydatki bardzo niedoszacowane, zarówno w zakresie lecznictwa szpitalnego, jak i ambulatoryjnego, więc w najbliższym czasie będą wymagać nowych rozwiązań organizacyjnych i finansowych