Experimentally measurement and analysis of stress under foundation slab

Understanding of a load redistribution into subsoil below building foundation is an important knowledge for reliable design and its economy too. The article presents the results of a physical model of a foundation slab and its interaction with the subsoil. The interactions were investigated comprehensively by monitoring the developments of stress in the subsoil and foundation slab settlement during its loading. The load acting on the foundation was applied by strutting the hydraulic press against heavy steel frame which was established by the Department of Building Structures, Faculty of Civil Engineering of VSB -TU Ostrava for this purpose. The preparatory phase of the present experiment involved the homogenization of soil during which trio pressure cells in three horizons were gradually fitted. The quality of homogenization was checked on an ongoing basis through field tests: dynamic penetration load test, dynamic plate load test and seismic measurement of foundation slab response. Finally, the homogenized soil was subjected to mechanical analysis to determine the strength and deformation parameters for basic Mohr-Coulomb constitutive model.Web of Science133513512

Opazovanje in simulacija nestabilnih pogojev med kontinuirnim litjem

Continuous casting comprises thermal, mechanical and chemical processes running in a complex system that contains a number of elements, such as a solidifying steel strand, a mould with an oscillation mechanism, a withdrawal mechanism, a water cooling sub-system with nozzles, several control sub-systems, etc. An external observer might see the process as robust and stable, but in reality there are fluctuations in the internal thermal and mechanical quantities, reflected in the structure and quality of the product. The research on unsteady behaviour of the quantities such as a solidifying strand temperature field, solid shell thickness and metallurgical length was conducted using an industrial diagnostic system DGS complemented with special measurement equipment and a thermal numerical model. Selected results of the monitoring and simulation of the non-standard process states are shown and analysed in the paper. Methods for determining the boundary conditions for the numerical model are also presented. The effect of the Leidenfrost phenomenon on the heat-transfer coefficient during water cooling by nozzles is also discussed. Since the determination of precise and immediate boundary conditions has technical limits, the model provides only smoothed values in time and space. As knowledge of the instantaneous state of the fluctuating process is a prerequisite for achieving quality and defect-free production, it is appropriate to complement the thermal numerical model by on-line monitoring of the machine's internal state. The results of the simulations are closely linked to the real process data.Kontinuirno litje obsega termične, mehanske in kemične procese, ki tečejo v kompleksnem sistemu, ki vsebuje vrsto elementov, kot so: strjujoča se jeklena žila (gredica), kokila z oscilacijskim mehanizmom, izvlečni mehanizem, vodno hlajenje s podsistemom hladilnih šob, več kontrolnih podsistemov itd. Zunanji opazovalec lahko vidi proces kot robusten in stabilen, toda v resnici imamo vrsto fluktuacij (nihanj) internih termičnih in mehanskih veličin in kakovosti produkta (nastajajoče konti lite gredice). Raziskave (časovno) nestabilnega obnašanja veličin, kot so: temperaturno polje strjujoče se konti gredice, debelina trdne skorje in metalurška dolžina, so avtorji prispevka izvajali z industrijskim diagnostičnim sistemom (DGS), dopolnjenim s specialno merilno opremo in termičnim numeričnim modelom. V članku avtorji predstavljajo izbrane rezultate analiz, opazovanja in simulacije nestandardni procesnih stanj. Prav tako predstavljajo metode določevanja robnih pogojev za numerični model. Diskusija obsega tudi t.i. Leidenfrostov fenomen in njegov vpliv na koeficient prenosa toplote med vodnim hlajenjem s šobami. Za natančno določitev vsakokratnih robnih pogojev obstajajo tehnične omejitve. Zato so v postavljenem modelu uporabljene le zglajene vrednosti v realnem času in prostoru. Poznavanje trenutnega stanja ves čas spreminjajočega stanja, je predpogoj za doseganje kvalitetne proizvodnje brez napak. Zato je primerno uporabljati termični numerični model s tekočim (on-line) oz. neposrednim spremljanjem internega stanja na konti livni napravi. Predstavljeni rezultati so tesno povezani z realnimi procesnimi podatki.Web of Science52211711

Russian Disinformation Threat : Comparative Case Study of Czech and Slovak Approaches

This comparative case analysis focuses on the approaches of the Czech and Slovak governments to Russian disinformation activities, with particular attention to the securitization of the threat. The paper argues that the extent of energy relations with Russia plays an important role in the securitization of the threat posed by the said state. It employs a rational model of policy-making to better understand the rationale for the decisions of the actors leading to the different approaches taken by the governments of the examined states. The analysis shows that while the Czech approach seems to be driven mostly by security interests, in Slovakia, the economic goals are of primary importance, with the primary factor being the importance of energy relations with Russia. The Czech approach is considered as an appropriate one in this paper, as it allows for more objective threat assessment and consequently better preparedness and resilience, whereas a rather pragmatic approach of Slovakia leads to increasing vulnerability of disinformation activities

Power restoration in medium voltage network using multiagent system

The article describes a novel approach to a power restoration in medium voltage power distribution network. It focuses primary at searching of a new network configuration enabling to minimalize the size of faulted area and to restore the power for the highest possible number of loads. It describes characteristic features of medium voltage power distribution network and discusses the implementation of the presented approach in existing networks. A software tool, developed by the authors, including physical simulation of model network and its autonomous control system is described. An example of fault situation in a virtual distribution network is presented. Afterwards, the solution of restoration problem by proposed multiagent system is simulated using the software tool described in the paper

ポテンショスタティック法による歯科用アマルガムの耐食性試験

The aim of this study was to examine the validity of a test method (report from ISO/TC meeting in London, October 1998, document N55) for the corrosion resistance of amalgam, considered for adoption as ISO (International Organization for Standardization) test. The corrosion resistance of six types of amalgam was evaluated using the proposed potentiostatic test (N55). The test procedure (N55) was found to be relatively simple and provide reproducible results. Therefore the proposed potentiostatic test can be justified as a standard test of corrosion resistance for dental amalgams

THE EFFECT OF SOIL GRAIN SIZE ON THE DEFORMATION PROPERTIES OF REINFORCED GEOCELL LAYERS

The effect of backfill material grading on the behaviour of geocell reinforced layers was experimentally investigated in this study. A series of loading tests were performed on a model with geocell reinforced and unreinforced layers. Five types of crushed aggregates were used as backfill materials in the experiment. The results showed that geocell reinforcement increased the deformation parameters. The rate of increase of the deformation characteristics depended on the backfill material grading

Construction Technological Project of "Campus Brno - Bohunice"

Předmětem diplomové práce je zpracování technologického projektu univerzitního kampusu v Brně - Bohunicích. Práce obsahuje komplexní studii realizaci hlavních technologických etap postupu výstavby řešených objektů UKB, konkrétně A25 a A36. Dále je zde technická zpráva, technologické postupy provádění ocelového nosného systému a monolitických železobetonových konstrukcí. Kontrolní a zkušební plán na řešené předpisy, časový plán, návrh strojní sestavy a plán BOZP.The subject of the Diploma thesis is the technological project of the university campus in Brno - Bohunice. The work includes a complex study of the realizacion of the main technological steps in the construction of buildings UKB, namely the A25 and A36. There is the technical report, technology processes steel bearing system and monolithic reinforced concrete structures. Inspection and test plan for addressing regulations, timetable of works, machine draft report, and occupational health and safety plan