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Stress state rock mass monitoring ahead of longwall No. II/501/C, Mine Staszic-Wujek, PGG, Poland -Project RFCS DD-MET
Waclawik, Petr; Kukutsch, Radovan; Staš, Lubomír; Souček, Kamil; Vavro, Leona; Vavro, Martin; Kubina, Lukáš; Schuchová, Kristýna
2022 - anglický
For designing precisely the reinforcement of mine gate and reinforcing underground structures in general, knowing stress and deformation states in the rock massive in the immediate vicinity of these mine works as precisely as possible is absolutely decisive. In order to verify the rock mass stress state and its changes induced by longwall mining, the monitoring of rock mass stress changing in connection with the mine out of the coal seam No. 501, longwall face No. II/501/C in the Mine Staszic-Wujek, Poland, was suggested. The aim of the contractual research was the realisation and interpretation of the rock stress state monitoring using the CCBO (Compact Conical ended Borehole Overcoring method) and CCBM (Compact Conical ended Borehole Monitoring method) probes in the forefield of mentioned longwall face within geotechnical station. To verify stress monitoring, the survey of the state of the longwall gate was carried out using a pulse 3D scanner. The purpose was to capture deformation changes ahead of the advancing longwall face, specifically, at five stages in the ± 20 m section on each side from the installed geotechnical station.
Klíčová slova:
pre-mining stress; induced stress; 3D laser scanning
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Stress state rock mass monitoring ahead of longwall No. II/501/C, Mine Staszic-Wujek, PGG, Poland -Project RFCS DD-MET
For designing precisely the reinforcement of mine gate and reinforcing underground structures in general, knowing stress and deformation states in the rock massive in the immediate vicinity of these ...
TM03000027-V6: ESC 3 - Posouzení vlivu na přesnost navigačních systémů GNSS - Evaluation of factors influencing the GNSS positioning accuracy
Urbář, Jaroslav; Suchánek, P.; Chum, Jaroslav
2022 - anglický
Technická zpráva o vlivu na přesnost navigačních systémů GNSS. Získaná data k ověření vlivu na přesnost navigačních systémů GNSS při výskytu MSTID v ionosféře. \n\nTechnical report analyzing the effect of MSTIDs on an accuracy of GNSS based positioning. The analysis should be performed based on experimentally obtained data.\n
Klíčová slova:
medium-scale traveling ionospheric disturbances (MSTIDs); Global Navigation Satellite System (GNSS); GADIOD; GNSS
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
TM03000027-V6: ESC 3 - Posouzení vlivu na přesnost navigačních systémů GNSS - Evaluation of factors influencing the GNSS positioning accuracy
Technická zpráva o vlivu na přesnost navigačních systémů GNSS. Získaná data k ověření vlivu na přesnost navigačních systémů GNSS při výskytu MSTID v ionosféře. \n\nTechnical report analyzing the ...
Annular impinging jets and an active control of hysteretic effects
Devani, Yogendrasasidhar; Antošová, Zuzana; Trávníček, Zdeněk
2022 - anglický
An annular air jet with and without flow control was studied experimentally using flow visualization and measurements of the wall pressure and flow velocity by the Pitot and Prandtl probes and the hot-wire anemometer. To investigate flow control swirling effects, eight synthetic jets were generated from the annular nozzle center body.The experiments cover Reynolds numbers 4000–10000 (evaluated from the outer exit diameter of the annular nozzle). For Re<9000, the bistability and hysteresis were identified and two different flow field patterns (A and B) were found under the same boundary conditions. For A pattern, a small recirculation area (bubble) of separated flow is attached to the nozzle center body. For B pattern, a large recirculation area of separated flow bridges entire nozzle-to-wall distance. For higher Re > 9000, the bistability and hysteresis were not found.Flow control swirling effects causes suppression of the hysteresis. Moreover, weak flow control causes that the entire annular jet is forced into a precessing motion.
Klíčová slova:
annular jet; impinging jet; bistability; hysteresis
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Annular impinging jets and an active control of hysteretic effects
An annular air jet with and without flow control was studied experimentally using flow visualization and measurements of the wall pressure and flow velocity by the Pitot and Prandtl probes and the ...
Conservation standards for archaeological sites
Drdácký, Miloš; Drdácký, Tomáš; Novotný, Jakub; Přechová, Barbora
2022 - anglický
The report provides a set of principles for the preventive protection, conservation and management of archaeological sites exposed to the threats of global hazards, especially natural disasters and long-term weather effects.\n\n
Klíčová slova:
conservation; archaeological sites; Danube limes monument; natural hazards; preventive measures
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Conservation standards for archaeological sites
The report provides a set of principles for the preventive protection, conservation and management of archaeological sites exposed to the threats of global hazards, especially natural disasters and ...
Structural mapping of exploration geotechnical boreholes walls within 2nd phase – Decline
Waclawik, Petr; Schuchová, Kristýna; Kukutsch, Radovan; Georgiou, Lucie
2022 - anglický
Structural-geological analysis, i.e. fracturing assessment of the walls of geotechnical boreholes (CIS38 and CIS39) within the projected Decline in lithium exploratory area was carried out on the basis of optical (OPTV) and acoustic televiewer (HiRAT) records evaluation. HiRAT and OPTV probes are part of the Robertson Geologging logging equipment. The apparatus has an electric winch with a four core logging cable, which transmits the data recorded by the probes via a data logger to a computer. The spatial data obtained from interpretation of the geotechnical boreholes records were structurally analysed. The submitted research report comprehensively summarises the findings obtained from the structural mapping of geotechnical boreholes. On the basis measured data the rock mass quality evaluation of boreholes walls were additionally done. The complex data have been allowed very precise analysis of rock mass structural conditions, which are necessary for design of opening mine working.
Klíčová slova:
geotechnical boreholes; structural mapping; geotechnics
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Structural mapping of exploration geotechnical boreholes walls within 2nd phase – Decline
Structural-geological analysis, i.e. fracturing assessment of the walls of geotechnical boreholes (CIS38 and CIS39) within the projected Decline in lithium exploratory area was carried out on the ...
Final Report of the Centre of Excellence for Nonlinear Dynamic Behaviour of Advanced Materials in Engineering
Parma, Slavomír; Gabriel, Dušan
2022 - anglický
This final report presents the CeNDYNMAT Center of Excellence, which was established at the Institute of Thermomechanics of the Czech Academy of Sciences in 2016 and ended in 2022. The report summarizes the most important scientific results of the center. It also gives an overview of the main outcomes and developments of the project, including budgeting, purchasing instrumentation, international cooperation and organization of conferences and summer courses.
Klíčová slova:
nonlinear dynamic behavior; advanced materials; metal plasticity
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Final Report of the Centre of Excellence for Nonlinear Dynamic Behaviour of Advanced Materials in Engineering
This final report presents the CeNDYNMAT Center of Excellence, which was established at the Institute of Thermomechanics of the Czech Academy of Sciences in 2016 and ended in 2022. The report ...
Aerodynamic Measurements on Transonic Compressor Blade Cascades KR-D-5 and KR-D-6
Šimurda, David; Hála, Jindřich; Luxa, Martin
2022 - anglický
This report contains results and evaluation of aerodynamic measurements conducted on two variant transonic compressor blade cascades with MCA profile (KR-D-5) and DCA profile (KR-D-6).
Klíčová slova:
compressor blade cascade; experiment; transonic flow; MCA profile; DCA profile
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Aerodynamic Measurements on Transonic Compressor Blade Cascades KR-D-5 and KR-D-6
This report contains results and evaluation of aerodynamic measurements conducted on two variant transonic compressor blade cascades with MCA profile (KR-D-5) and DCA profile (KR-D-6).
Survey of the use of propane as refrigerant R290 in cooling circuits and heat pumps
Aminian, Ali; Prokopová, Olga; Vinš, Václav
2022 - anglický
The technical report presents a review on the application of propane as refrigerant R290 in cooling circuits and heat pumps (HVAC). Safety risks of R290 used in HVAC are addressed according to ANSI/ASHRAE and EN standards. Comparison of thermophysical properties of propane with other refrigerants, solubility and miscibility of propane in compressor oils and heat transfer in condenser and evaporator are discussed. The main aim of the study is to provide an overview about the potential use of propane in the cooling circuit and heat pump for the hydrogen bus developed by the SOR Libchavy company.
Klíčová slova:
cooling circuit; heat pump; hydrogen bus; refrigerant
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Survey of the use of propane as refrigerant R290 in cooling circuits and heat pumps
The technical report presents a review on the application of propane as refrigerant R290 in cooling circuits and heat pumps (HVAC). Safety risks of R290 used in HVAC are addressed according to ...
A Measure of Variability WIthin Parametric Families of Continuous Distributions
Fabián, Zdeněk
2022 - anglický
A continuous probability measure on an open interval of the real line induces in it a unique geometry, "center of gravity" of which is the typical value of the distribution. In the paper is identified a score variance as a finite measure of variability of distributions with respect to the typical value and discussed its properties and methods of estimation. Itroducing a generalized Rao distance in the sample space one can appraise the precision of the estimate of the typical value.
Klíčová slova:
scalar-valued score; score mean; score variance; distance in the sample space
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
A Measure of Variability WIthin Parametric Families of Continuous Distributions
A continuous probability measure on an open interval of the real line induces in it a unique geometry, "center of gravity" of which is the typical value of the distribution. In the paper is identified ...
Score correlation for skewed distributions
Fabián, Zdeněk
2022 - anglický
Based on the new concept of the scalar-valued score function of continuous distributions we introduce the score correlation coefficient ”tai-lored” to the assumed probabilistic model and study its properties by means of simulation experiments. It appeared that the new correlation method is useful for enormously skewed distributions.
Klíčová slova:
Scalar-valued score; score coefficient of variation; Monte Carlo
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Score correlation for skewed distributions
Based on the new concept of the scalar-valued score function of continuous distributions we introduce the score correlation coefficient ”tai-lored” to the assumed probabilistic model and study its ...
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