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212. Kinetics and mechanism of curing epoxy / anhydride systems

Creator:
Kolář, František and Svítilová, Jaroslava
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, epoxidové pryskyřice, kinetika, epoxy resins, kinetics, anhydrides, catalyzed, model reactions, 7, and 551
Language:
English
Description:
The paper reports the results of studying the kinetics of DGEBA reactions with maleic anhydride catalyzed by N, N-dimethyl aniline (DMA). This stuffs are used as phot oelastic model materials. The origination of monoester was studied separately on a model reaction of maleic anhydride with isopropyl alcohol. The subsequent reaction of epox y groups with monoester was examined on a system of epoxy resin and isopropyl maleic monoester. The curing process depends significantly on the content of hydroxyl groups in the system., František Kolář and Jaroslava Svítilová., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

213. Kinetics of Fe-catalyzed gasification of chars from lignite admixtures

Creator:
Pavel Straka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, zplyňování, polymery, kinetika, gasification, polymers, kinetics, magnetite, 7, and 551
Language:
English
Description:
Measurements of the gasification rate of chars from lignite with admixtures by steam or CO2 showed that the admixtures of polymers, celluloses and wood reduce reactivity of resulting chars. The decrease of reactivity significantly manifests itself at both 800 °C and 900 °C. This is caused mainly by lower inner surface area which resists the gasification reactions. This negative phenomenon can be compensated by addition of magnetite, which acts as Fe-catalyst of the reactions of chars with steam as well as CO2 and accelerates the gasification. Through the isoconversional analysis, it was proven that the presence of magnetite significantly lowers the effective activation energy of these reactions, thus accelerating their course. The measurements of the reaction rate showed that it leads to a two- or three-fold acceleration of gasification., Pavel Straka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

214. Krajiny snů: nerealizované projekty od středověku do současnosti

Creator:
Eva Semotanová and Robert Šimůnek
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Historická geografie, Výzkumné centrum historické geografie, Krajiny snů (11. : 2015 : Praha, Česko), věda a společnost, historická geografie, science and society, historical geography, 7, and 913:94
Language:
Czech
Description:
Takto byla s trochou nadsázky nazvána 11. historickogeografická konference, kterou 28. ledna 2015 uspořádaly v prostorách PřF UK na pražském Albertově Výzkumné centrum historické geografie - Historical Geography Research Centre (grantový projekt excelence GA ČR P410/12/G113, jehož řešiteli jsou Historický ústav AV ČR a Katedra sociální geografie a regionálního rozvoje Přírodovědecké fakulty UK) a Komise pro historickou geografii. and Eva Semotanová, Robert Šimůnek.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

215. Landslide susceptibility assessment in urbanized areas: example from flysch Carpathians, Czech Republic

Creator:
Jan Klimeš and Novotný, Roman
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, sesuvy půdy, rozvoj měst, landslides, urban development, Česko, Czechia, landslide susceptibility assessment, multi-variety statistical analysis, flysh highlands, 7, and 551
Language:
English
Description:
The ongoing development of landslide prone regions increases future potential losses caused by landslide occurrence. The first step towards landslide mitigation on a regional scale is a susceptibility assessment. This study focuses on the area surrounding the regional capital of Zlín, in the Outer Western Carpathians. The city is located in the flysch highlands. Statistical analysis of the distribution of landslide scarps was undertaken in relation to various preparatory factors (geology, slope angle, slope aspect, slope curvature, distance from closest stream). This analysis provided insights into the main initiating factors and allowed our results to be compared with other studies in similar regions. Thereafter, a regional landslide susceptibility assessment was undertaken. The model performance was evaluated with respect to the landslide information used during its preparation and with a separate validation dataset. The results show that the main predisposing factors are the claystone rich bedrock unit, thick accumulations of slope sediments, and slope angles between 10° and 15°. The possible application of the presented results for urban planning purposes is also outlined., Jan Klimeš and Roman Novotný., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

216. Landslides mapping in Roznow Lake vicinity, Poland using airborne laser scanning data

Creator:
Borkowski, Andrzej, Perski, Zbigniew, Wojciechowski, Tomasz, Jóźków, Grzegorz, and Wójcik, Antoni
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, letecké laserové skenování, sesuvy půdy, airborne laser scanning, landslides, Karpaty (pohoří), Carpathian Mountains, landslides mapping, 7, and 551
Language:
English
Description:
Southern Poland, especially Polish Carpathians, is a region affected by strong mass-movements. The importance of massmovements problems has been taken into consideration on the governmental level and Landslide Counteracting System (SOPO) program was launched in 2008. The main purpose of this program is to create inventory and map all active and inactive landslides and landslide prone areas in Poland. However, in case of such gigantic work, the traditional mapping methods meet sometimes their limitations. In order to overcome some of efficiency problems the new technology, the application of airborne laser scanning was tested. The main purpose of presented work is to test whether the LiDAR DTM is capable to support geological interpretation and landslide detection on steep and forested slopes for the purposes of landslide mapping within SOPO project. For this purpose the ALS dataset covering 40 km2 of the area near Roznow Lake in Polish Carpathians have been acquired in April 2010. The average scanning resolution was 7 points/m2 and LiteMapper 6800i system based on the full waveform, Riegl LMS-Q680i scanner have been used. Acquired point cloud was applied to generate DTM of 0.5 m resolution. For efficiency test purposes the detailed geological interpretation of constructed ALS DTM was focused on already well mapped large Zbyszyce landslide. The extents of the landslide and the zones of different level of activity have been mapped and then verified with field data. During the detailed analysis it was found that the level of the details of ALS DTM allows also performing morphometric analysis on landslides., Andrzej Borokowski, Zbigniew Perski, Tomasz Wojciechowski, Grzegorz Jóźków and Antoni Wójcik., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

217. Lanthanide tetrad effect in limestone: a tool to environment analysis of the ruteh formation, NW Iran

Creator:
Abedini, Ali, Rezaei Azizi, Mansour, and Calagari, Ali Asghar
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
vápenec, limestones, Írán, Iran, REE, tetrad effect, chemical environment analysis, 7, and 551
Language:
English
Description:
Exhibition of lanthanide tetrad effect in PAAS-normalized REE patterns, and non-CHARAC (non-CHArge-RAdius Control) behavior of Y/Ho and Zr/Hf in limestone of the Ruteh Formation, Kanigorgeh district (NW Iran), were studied in order to understand the reasons of occurrence of lanthanides tetrad effects. The computed values show that the third and fourth tetrads can be used as a good and powerful geochemical tool for investigation of physicochemical conditions of the depositional environment of the limestones. Here, a new mathematical-based method using polar coordination system for tetrad effect values (Tp) was used to evaluate under studying limestone. The correlation between Tp and some geochemical parameters revealed that the limestone was likely deposited under two different conditions. The obtained results indicated that paleo-redox conditions, adsorption and scavenging by kaolinite and metallic oxides, degree of detrital input, diagenesis intensity, and complexation by polycarbonate ligands are likely the main mechanisms for occurrence of tetrad effect phenomenon in REE distribution patterns in the limestone. This means that tetrad effect phenomenon in REE distribution patterns of limestone can be applied as a good geochemical indicator to evaluate the deposition conditions in limestones., Ali Abedini, Mansour Rezaei Azizi and Ali Asghar Calagari., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

218. Layered double hydroxides intercalated with organic anions and their application in preparation of LDH/polymer nanocomposites

Creator:
Kovanda, František, Jindová, Eva, Barbora Doušová, Koloušek, David, Pleštil, Josef, and Sedláková, Zdeňka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, nanokompozitní materiály, nanocomposites, hydrotalcite, layered double hydroxides, intercalation, polymethacrylate, nanocomposite materials, 7, and 551
Language:
English
Description:
The intercalation of organic anions, namely acrylate, methacrylate, 2-acrylamido-2-me thyl-1-propanesulfonate (AMPS), 4-vinylbenzoate, and 4,4’-azobis(4-cyanopentanoate) into Mg-Al and Zn-Al layered double hydroxides (LDHs) was studied. The coprecipitated Mg-Al-NO 3 and Zn-Al-NO 3 hydrotalcite-like compounds with M II /Al molar ratio of 2 were used as precursors. The anion exchange and rehydration of calcined LDH precursors were applied for the intercalation. The anion exchange appeared to be the most effective method; all examined organicanions were intercalated successfully by this way both in Mg-Al and Zn-Al host structur es. The intercalated LDHs were us ed as comonomer and initiator for preparation o f LDH/polymethacrylate nanocomposites: mixture of monomer and LDHs intercalated with organic anions were dispersed in aqueous phase and then the emulsion polym erization was performed in the presence of inorganic (nano)particles to obtain polybutylmethacrylate hybrid latexes. Na nostructured hybrid materials containing a low amount (1 - 3 wt%) of inorganic nanofiller were prepared. Particles with size of 60 - 100 nm were detected by dynamic light scattering and small-angle X-ray scattering methods. Furthermore, a hydrophobization of LDH nanof illers with dodecylsulfate (DS) was tested in order to facilitate their dispersion in the polymer matrix. A minor part of AMPS anions was incorporated into Mg-Al-DS LDH during anion exchange in the aqueous solution containing AMPS. Us ing Mg-Al-DS LDH modified w ith AMPS, the nanocomposites were obtained by emulsion polymerization and also by the solution polymer ization in 1-methyl-2-pyrolidone., František Kovanda, Eva Jindová, Barbora Doušová, David Koloušek, Josef Pleštil and Zdeňka Sedláková., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

219. Local effects in peak accelerations caused by mining tremors in Bytom Syncline region (Upper Silesia)

Creator:
Fref, Adam and Zuberek, Wacław Marian
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, amplification of vibration, HVSR technique, local effects, attenuation relation, 7, and 551
Language:
English
Description:
This paper shows how the local effects can change the value of maximum accelerations from mining-induced tremors. The analysis was carried out basing on data collected from acceleration stations installed in Bytom Syncline region (Upper Silesia). The estimation of the local effects was obtained on the basis of deviations from the attenuation relation. The accelerograms were recorded from the mining tremors in low seismic energy range and in epicentral distances in the range from 500m to 5000m. The obtained re sults were correlated with results from Horiz ontal to Vertical Spectral Ratio (HVSR) technique. This method is based on simple theoretical founda tion and is commonly used in natural seismicity studies. Our results show that the H/V ratio technique gives a reasonable estimate of the surface amplification for frequency range between about 2 and 8 Hz. In case of simple geology and when the signal to noise is adequately high the results are the best. All the results show that there occur local effects., Adam Fref and Wacław Marian Zuberek., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

220. Local geodynamics of the territory of Dniester pumped storage power plant

Creator:
Savchyn, Ihor and Vaskovets, Serhii
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
geodynamika, geomechanika, geofyzika, geologie, satelitní navigační systémy, satellite navigation systems, geodynamics, geomechanics, geophysics, geology, geotechnický monitoring, geotechnical monitoring, Dněstr (Ukrajina a Moldavsko : řeka : oblast), Dniester River Valley (Ukraine and Moldova), dilatace, recent local horizontal movements, GNSS, dilatation, monitoring, Dniester PSPP, 7, and 551
Language:
English
Description:
The aim of the study is to identify the recent local geodynamic processes on the territory of the Dniester PSPP (Ukraine), which arose as a result of the additional man-caused load during the construction of hydro-technical structures. The research is based on the results of 17 cycles of periodic static GNSS campaigns conducted during 2004-2017. In this work the vectors of horizontal displacement of the reference GNSS network points of Dniester PSPP are determined and their scheme is constructed. On the basis of average vectors of horizontal movement velocities during 2004-2017, the value of the velocities of dilatation - the parameter of Earth surface deformation which characterises the relative area expansion or compression, is calculated. As a result of the analysis of velocity distribution of the dilatation of Dniester PSPP territory, the areas of extreme values of compression and stretching are revealed, which testify to the increased geodynamic activity of the pivot part, as well as the main structures of the construction. and Savchyn Ihor, Vaskovets Serhii.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public