Water-Tight Concrete Constructions and Directives for their Design and Realization

2017 ◽  
Vol 908 ◽  
pp. 154-158
Author(s):  
Adam Hubáček ◽  
Iveta Hájková
Keyword(s):  
Compressive Strength ◽  
Czech Republic ◽  
Experimental Work ◽  
Frost Resistance ◽  
Crack Formation ◽  
Current Knowledge ◽  
Laboratory Work ◽  
The Czech Republic ◽  
Early Stages ◽  
Heat Development

The paper describes problems of water-tight concrete constructions, their design, manufacture and testing of quality in accordance with regulations and directives used in the Czech Republic and abroad. Current knowledge of water-tight constructions and water-tight concrete imply that main focus is on problems of use of water-tight concrete for construction of so-called white bath and preventing crack formation in concrete. Laboratory work is focused mainly on design of concrete based on individual regulations. Subsequently, influence of various types of cement and additions partly replacing cement on properties of water-tight concrete is examined. Research of heat development during hydration at early stages of maturing is and inseparable part of the experimental work, as well as development of compressive strength, water-tightness and frost resistance of concrete

scholarly journals Effect of missense mutation Asp298Asn in MC4R on growth and fatness traits in commercial pig crosses in the Czech Republic

2011 ◽  
Vol 56 (No. 4) ◽  
pp. 176-180 ◽  
Author(s):  
V. Dvořáková ◽  
R. Stupka ◽  
M. Šprysl ◽  
J. Čítek ◽  
M. Okrouhlá ◽  
...  
Keyword(s):  
Growth Rate ◽  
Czech Republic ◽  
Missense Mutation ◽  
Feed Intake ◽  
Current Knowledge ◽  
Production Traits ◽  
The Czech Republic ◽  
Mc4r Gene ◽  
Longissimus Lumborum ◽  
Commercial Farms

The current knowledge of factors regulating voluntary feed intake in pigs is quite limited. The objective of this study was to test the influence of the missense mutation p.Asp298Asn (AF087937:c.746G>A) of the MC4R gene on selected production traits in pig crosses. These crosses are commonly used on commercial farms in the Czech Republic. The allele frequencies of c.746G>A were as follows: G allele – 0.59 and A allele – 0.41. We detected statistically significant differences in the content of intramuscular fat in the musculus longissimus lumborum et thoracis, and a similar trend was observed in shoulder and neck. A allele correlated with higher values of fatness and G allele with a higher percentage of lean meat. However, we did not find any significant influence on either feed intake or growth rate in this study. For another mutation, p.Arg236His (NM_214173.1:c.707G>A), frequencies of alleles were disproportional (A allele – 0.02 and G allele – 0.98), only two genotypes were observed (AG and GG) and linkage disequilibrium was not detected. Therefore, we assume that the effect of this polymorphism on growth rate and fatness in the Czech population of pigs is negligible.

Study of Properties of Concrete for Water-Tight Tunnel Lining

2015 ◽  
Vol 1106 ◽  
pp. 17-20 ◽  
Author(s):  
Adam Hubáček ◽  
Tomáš Jarolím ◽  
Petra Macháňová
Keyword(s):  
Compressive Strength ◽  
Czech Republic ◽  
Fresh Concrete ◽  
Concrete Structures ◽  
Tunnel Lining ◽  
Hardened Concrete ◽  
The Czech Republic ◽  
Water Durability ◽  
Pressure Water

The paper deals with the topic of concrete for water-tight tunnel lining. This theme is currently very topical both in the Czech Republic and abroad. The focus is on requirements and properties of fresh concrete for manufacture of these specific concrete structures. Properties of hardened concrete will be examined, too: compressive strength, resistance to pressure water, durability and other parameters.

scholarly journals Application of current knowledge and trends in sports training of top level volleyball teams in the Czech Republic

2010 ◽  
Vol 33 (1) ◽  
pp. 81-97 ◽  
Author(s):  
Michal Lehnert ◽  
Jiří Stierand ◽  
František Chmelík ◽  
Zdeněk Haník
Keyword(s):  
Czech Republic ◽  
Current Knowledge ◽  
Sports Training ◽  
The Czech Republic

African Trachelomonas saccasii found in a European mesotrophic pond (Czech Republic). Implication for euglenoid biogeography and recommendations for euglenoid flagship species

Phytotaxa ◽  
2018 ◽  
Vol 334 (3) ◽  
pp. 201 ◽  
Author(s):  
JOSEF JURÁŇ ◽  
ALAIN COUTÉ
Keyword(s):  
Czech Republic ◽  
Ivory Coast ◽  
Current Knowledge ◽  
Global Distribution ◽  
Flagship Species ◽  
Original Material ◽  
The Czech Republic ◽  
Worldwide Distribution ◽  
Initial Description ◽  
A New Species

This work reports the identification of Trachelomonas saccasii in a small mesotrophic pond in the Czech Republic. Trachelomonas saccasii was originally described from a small lake in Ivory Coast (West Africa) in 2009. This report from the Czech Republic is the second known record of this taxon after the initial description of this species. Trachelomonas saccasii represents a new species of euglenoid for the Czech Republic and Europe. This finding highlights the current knowledge gaps regarding the biogeography and worldwide distribution of euglenoids. The first aim of this study is to describe the identification of Trachelomonas saccasii using light and scanning electron microscopy and to compare it with the description of the original material from Africa. Second, we discuss the current knowledge of euglenophyte biogeography and propose methods that could be used to explore biogeographical distributions using floristic databases. These methods could be useful especially for the following flagship species: Colacium epiphyticum, C. minimum, Lepocinclis crassicollis, Phacus plicatus, Trachelomonas argentinensis, T. hemispherica and T. magdaleniana. This study provides new data on the global distribution of euglenoids and proposes possible strategies to obtain further information about the global distribution of this group of microorganisms.

Systems and Regulations for Design and Application of Water-Tight Concrete Structures

2018 ◽  
Vol 272 ◽  
pp. 203-208
Author(s):  
Adam Hubáček
Keyword(s):  
Compressive Strength ◽  
Czech Republic ◽  
Concrete Structure ◽  
Fresh Concrete ◽  
Concrete Structures ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
The Czech Republic ◽  
Pressure Water ◽  
Design And Application

The paper focuses on the problems of concrete for water-tight concrete structure and with systém and regulations for design and application of these structures. The theme is currently quite topical in the Czech Republic and abroad. The accent is put particularly on the requirements and properties of fresh concrete or self-compacting concrete for manufacture of specific concrete structures. Properties of hardened concrete will be also observed; in particular compressive strength, resistance to pressure water, durability and other parameters.

Commercially Used Sulphate Binders Based on Anhydrite

2012 ◽  
Vol 598 ◽  
pp. 314-317 ◽  
Author(s):  
Dominik Gazdič ◽  
Marcela Fridrichová ◽  
Karel Dvořák
Keyword(s):  
Czech Republic ◽  
Experimental Work ◽  
Applied Research ◽  
Initial Study ◽  
Hydration Process ◽  
The Czech Republic ◽  
Know How ◽  
Binding Phase ◽  
German Producer ◽  
The Given

The work was devoted to the analysis of a commercially manufactured binder imported from Germany which is supposed to represent a natural anhydrite according to the accompanying documentation, industrially modified by hydration process activating agents. A similar analysis of the anhydrite binder commercially manufactured in Germany was carried out at the very beginning of investigation into the given problem. In the introductory study of applied research engaged in the feasibility of preparation of self-levelling mixes based on anhydrite binder, a specimen binder made by a German producer declared as a purely anhydrite binder, was analysed. However, it was found out by the analyses performed that this binder is a premium quality -gypsum according to all manifestations by a modified liquefying and retarding agent, possibly by other compounds. Due to potential changes that may have occurred since the initial study in the composition of the so-called anhydrite binders, exploration of composition of the binders currently used in the Czech Republic for preparation of self-levelling mixtures was carried out in this part of the experimental work. The exploration detected that the composition of the binding phase is the matter of know-how for the majority of companies, and as a result, the only one sample of binder has been obtained so far from the company which reserved their anonymity for this work.

Concrete with High Content of Fly Ash Intended for Constructions with Long Durability

2016 ◽  
Vol 249 ◽  
pp. 21-27 ◽  
Author(s):  
Adam Hubáček ◽  
Rudolf Hela
Keyword(s):  
Compressive Strength ◽  
Czech Republic ◽  
Fly Ash ◽  
Fresh Concrete ◽  
Ash Content ◽  
Hardened Concrete ◽  
The Czech Republic ◽  
Concrete Properties ◽  
Pressure Water ◽  
Long Life

The article deals with theme of high fly ash content concretes intended for long life constructions. Considering the still growing consumption of fly ash in construction concretes it is a live theme in the Czech Republic and abroad as well. The emphasis will be laid namely on characteristics and requirements for fresh concrete intended for construction of these specific concrete constructions. They are for instance waterproof constructions, tunnel linings, concretes for bridge and road constructions etc. Also the hardened concrete properties like compressive strength, resistance to pressure water, durability and further necessary parameters for obtainment of required properties of these concretes will be monitored.

Problems of Watertight Concrete for the Concrete Tunnel Lining

2014 ◽  
Vol 1000 ◽  
pp. 360-364
Author(s):  
Adam Hubáček
Keyword(s):  
Compressive Strength ◽  
Czech Republic ◽  
Fresh Concrete ◽  
Concrete Structures ◽  
Tunnel Lining ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
The Czech Republic ◽  
Water Durability ◽  
Pressure Water

The paper focuses on the problems of concrete for watertight tunnel lining. The theme is currently quite topical in the Czech Republic and abroad. The accent is put particularly on the requirements and properties of fresh concrete or self-compacting concrete for manufacture of specific concrete structures. Properties of hardened concrete will be also observed; in particular compressive strength, resistance to pressure water, durability and other parameters.

scholarly journals Human Prion Disorders: Review of the Current Literature and a Twenty-Year Experience of the National Surveillance Center in the Czech Republic

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1821
Author(s):  
Nikol Jankovska ◽  
Robert Rusina ◽  
Magdalena Bruzova ◽  
Eva Parobkova ◽  
Tomas Olejar ◽  
...  
Keyword(s):  
Czech Republic ◽  
Prion Protein ◽  
Active Surveillance ◽  
Current Knowledge ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathies ◽  
National Surveillance ◽  
Spongiform Encephalopathies ◽  
Tissue Samples ◽  
The Czech Republic

Human prion disorders (transmissible spongiform encephalopathies, TSEs) are unique, progressive, and fatal neurodegenerative diseases caused by aggregation of misfolded prion protein in neuronal tissue. Due to the potential transmission, human TSEs are under active surveillance in a majority of countries; in the Czech Republic data are centralized at the National surveillance center (NRL) which has a clinical and a neuropathological subdivision. The aim of our article is to review current knowledge about human TSEs and summarize the experience of active surveillance of human prion diseases in the Czech Republic during the last 20 years. Possible or probable TSEs undergo a mandatory autopsy using a standardized protocol. From 2001 to 2020, 305 cases of sporadic and genetic TSEs including 8 rare cases of Gerstmann–Sträussler–Scheinker syndrome (GSS) were confirmed. Additionally, in the Czech Republic, brain samples from all corneal donors have been tested by the NRL immunology laboratory to increase the safety of corneal transplants since January 2007. All tested 6590 corneal donor brain tissue samples were negative for prion protein deposits. Moreover, the routine use of diagnostic criteria including biomarkers are robust enough, and not even the COVID-19 pandemic has negatively impacted TSEs surveillance in the Czech Republic.

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