The Influence of Geometric Parameters of 3D Printed Structured Beds on Hydrodynamic Characteristics of Trickle-Bed Reactor
Nyklíčková, Kateřina
2024 - English The study examines a parametric set of POCS structures, where cubic cell is the basic element. The parameters such as strut diameter sd and cell size cs were varied1. These modifications are implemented with an emphasis on maintaining similar porosity and specific surface area for these structures. Keywords: trickle-bed reactor; pressure dop; POCS structures Available in digital repository of the ASCR The Influence of Geometric Parameters of 3D Printed Structured Beds on Hydrodynamic Characteristics of Trickle-Bed Reactor

The study examines a parametric set of POCS structures, where cubic cell is the basic element. The parameters such as strut diameter sd and cell size cs were varied1. These modifications are ...

Nyklíčková, Kateřina
Ústav chemických procesů, 2024

Evaluation of root system architecture and osmotic adaptation in barley
Klem, Karel; Findurová, Hana; Urban, Otmar; Holub, Petr
2024 - Czech Drought tolerance based on improving root system architecture, in particular by increasing rooting depth, increasing root density at deeper layers, or osmotic adjustment, is one of the most effective ways of adapting to drought, especially in conditions where sufficient water remains in the deeper soil layers during the dry season. Moreover, osmotic adjustment is a trait that allows plants to take up water even when water availability is limited, including the deeper soil layers. On the other hand, however, these are traits that are very difficult to evaluate, given their hidden nature or the need to laboriously excavate roots growing in the soil. This is also the reason why, despite their considerable importance, these features have long been overlooked. Breeding for these traits is done only indirectly by evaluating yield response to drought or indirect physiological or morphological parameters. \nIn this methodology, three methods for evaluating root system architecture or osmotic adjustment are presented which allow selection for specific root system architecture traits or osmotic adjustment, to be carried out on a large number of genotypes, using a relatively simple method based on the cultivation of roots on black filter paper, either hydroponically or aeroponically. This method allows a detailed analysis of root system architecture parameters that are important for drought tolerance and also a relatively easy test of osmotic adjustment by inducing osmotic stress with polyethylene glycol (PEG) solution. Both methods have been successfully validated, in the first case in a model experiment with nutrient deficiency, in which the effect on root system architecture is confounded, and in the second case in a set of barley genetic resources and varieties in which previously obtained information on drought tolerance of some genotypes was confirmed. \nAnother of the methods presented is the cultivation of roots in rhizoboxes filled with sand with a grid of spikes that hold the roots in the position in which they grew when washed. This method again allows the root system architecture to be assessed, but in this case under conditions that more closely match real soil conditions. The method was validated in three barley genotypes with contrasting root system vigor. The method used not only demonstrated the expected differences in rooting depth and root density distribution but also showed a relationship to the physiological response to reduced water availability in terms of photosynthetic CO2 assimilation rate. \nTherefore, all the methods presented here are suitable tools to help breeders in the selection of drought-tolerant barley genotypes. Tolerance vůči suchu, založená na zlepšení architektury kořenového systému, zejména pak na zvýšení hloubky zakořenění, zvýšení hustoty kořenů ve větší hloubce, nebo na schopnosti osmotického přizpůsobení, představuje jeden z nejefektivnějších způsobů adaptace k suchu, zejména pak v podmínkách, kde v období sucha zůstává dostatek vody v hlubších vrstvách půdy. Osmotické přizpůsobení navíc představuje znak, který umožňuje rostlinám příjem vody i při její omezené dostupnosti, včetně snížené dostupnosti v hlubších vrstvách půdy. Na druhou stranu se ovšem jedná o znaky, které jsou velmi obtížně vyhodnotitelné, vzhledem k jejich skrytému charakteru nebo nutnosti pracného odkrývání kořenů rostoucích v půdě. To je také důvod, proč jsou tyto znaky i přes jejich značný význam dlouhodobě přehlíženy. Šlechtění na tyto znaky probíhá fakticky pouze nepřímo pomocí vyhodnocení výnosové reakce na sucho, nebo nepřímých fyziologických či morfologických parametrů. \nV této metodice jsou představeny tři metody vyhodnocení architektury kořenového systému nebo osmotického přizpůsobení, které umožňují provedení selekce na zvolené znaky kořenového systému či osmotického přizpůsobení u velkého počtu genotypů s využitím relativně jednoduché metody založené na kultivaci kořenů na černém filtračním papíru ať již hydroponicky nebo aeroponicky. Tato metoda umožňuje podrobnou analýzu parametrů architektury kořenového systému, které jsou důležité pro toleranci k suchu a rovněž také relativně snadný test osmotického přizpůsobení pomocí indukce osmotického stresu roztokem polyethylen-glykolu (PEG). Obě metody byly úspěšně validovány, v prvním případě na modelovém experimentu s deficitem živin, u kterého je zmámý vliv na architekturu kořenového systému, a v druhém případě na souboru genetických zdrojů a odrůd ječmene, v němž byly potvrzeny dříve získané informace o toleranci některých genotypů k suchu. \nDalší z prezentovaných metod je kultivace kořenů v rhizoboxech naplněných pískem se sítí hrotů, které udržují kořeny při vymývání v poloze, v jakých kořeny rostly. Tato metoda umožňuje opět posouzení architektury kořenového systému, nicméně v tomto případě v podmínkách, které lépe odpovídají reálné situaci v půdě. Validace metody proběhla u tří genotypů ječmene s kontrastní mohutností kořenového systému. Použitá metoda prokázala nejen předpokládané rozdíly v hloubce zakořenění a distribuci hustoty kořenů, ale rovněž prokázala vztah k fyziologické odezvě na sníženou dostupnost vody v podobě rychlosti fotosyntetické asimilace CO2. \nVšechny předkládané metody proto představují vhodný nástroj, který by měl pomoci šlechtitelům v selekci genotypů ječmene tolerantních k suchu. \n\n Keywords: spring barley; drought; drought tolerance; root system architecture; root phenotyping; osmotic adjustment; plant physiology Available at various institutes of the ASCR Evaluation of root system architecture and osmotic adaptation in barley

Drought tolerance based on improving root system architecture, in particular by increasing rooting depth, increasing root density at deeper layers, or osmotic adjustment, is one of the most effective ...

Klem, Karel; Findurová, Hana; Urban, Otmar; Holub, Petr
Ústav výzkumu globální změny , 2024

Surface changes induced by plasma treatment and high temperature annealing of silicon dioxide microparticles
Babčenko, Oleg; Remeš, Zdeněk; Beranová, Klára; Kolářová, Kateřina; Lörinc, J.; Prošek, Z.; Tesárek, P.
2024 - English Due to the high surface to volume ratio, the particles’ surface properties modification defines its properties in general, which is crucial for their use. From this point of view, plasma processing or high temperature annealing can be considered as the universal techniques for efficient modification of materials in the form of powder. In this study, the silicon dioxide microparticles have been treated in a hydrogen, oxygen or vacuum by low temperature plasma or annealing. The change of SiO2 microparticles properties was investigated by photoluminescence spectroscopy at room and low temperature. High temperature annealing in hydrogen induced under UV excitation photoluminescence in the near UV and visible light indicating the change of defect states on the surface of the microparticles. We believe that observed findings clearly demonstrate useful method for analysis of SiO2 microparticles surface modification attractive also for fundamental research. Keywords: silicon dioxide; plasma treatment; annealing; photoluminescence; measuring setup Fulltext is available at external website. Surface changes induced by plasma treatment and high temperature annealing of silicon dioxide microparticles

Due to the high surface to volume ratio, the particles’ surface properties modification defines its properties in general, which is crucial for their use. From this point of view, plasma processing or ...

Babčenko, Oleg; Remeš, Zdeněk; Beranová, Klára; Kolářová, Kateřina; Lörinc, J.; Prošek, Z.; Tesárek, P.
Fyzikální ústav, 2024

MINOR PHASES IN TIN-RICH HISTORICAL MATERIALS
Michalcová, A.; Msallamová, Š.; Fink, D.; Friák, Martin
2024 - English The historical organ pipes used to be manufactured from tin and tin-lead alloys. The tin-rich organ pipes usually contained copper as alloying elements, which make them similar to modern lead free soldering materials. The historical organ pipe materials can be used as model materials for natural ageing of soldering materials. Tin pest is a term for modification from white tin to grey tin, which leads to degradation of tin or tin-rich alloys. The influence of individual alloying elements has not been reliably described, yet. Not only on the concentration of the alloying element, but also the distribution may play the important role. In dependence on heat-treatment, the Cu can be in the Sn matrix present in these forms: i) as large intermetallic particles after casting (Cu6Sn5), ii) as solid solution after homogenization annealing and iii) as fine precipitates after ageing. The microstructure of the real historical organ-pipes material was studied and it was proven that contradictionary to the equilibrium phase diagram the Cu enriched was observed. Keywords: Metallurgy; tin; copper; tin pest; tem Available at various institutes of the ASCR MINOR PHASES IN TIN-RICH HISTORICAL MATERIALS

The historical organ pipes used to be manufactured from tin and tin-lead alloys. The tin-rich organ pipes usually contained copper as alloying elements, which make them similar to modern lead free ...

Michalcová, A.; Msallamová, Š.; Fink, D.; Friák, Martin
Ústav fyziky materiálů, 2024

Book of Abstracts and Programme
Beneš, Hynek; Starý, Zdeněk
2024 - English The Book of Abstracts and Programme contains time order and the summaries of all the contributions to the international conference “Polymers for Sustainable Future 2024” was organized simultaneously as the 85th Prague Meeting on Macromolecules (PMM) and 11th Conference on Green Chemistry and Nanotechnologies in Polymeric Materials. The participants presented 84 lectures and 91 posters. Keywords: polymers; sustainable; green chemistry Available at various institutes of the ASCR Book of Abstracts and Programme

The Book of Abstracts and Programme contains time order and the summaries of all the contributions to the international conference “Polymers for Sustainable Future 2024” was organized simultaneously ...

Beneš, Hynek; Starý, Zdeněk
Ústav makromolekulární chemie, 2024

Studijní zkoušky pevnosti malty v omítce severního průčelí st. zámku Litomyšl
Drdácký, Miloš; Urushadze, Shota; Vála, Ondřej
2024 - Czech Available at various institutes of the ASCR Studijní zkoušky pevnosti malty v omítce severního průčelí st. zámku Litomyšl

Drdácký, Miloš; Urushadze, Shota; Vála, Ondřej
Ústav teoretické a aplikované mechaniky, 2024

Assessment of the condition and measuring of properties of the truss and 1st floor ceiling timber structures in the state-owned castle Hrádek u Nechanic, National Cultural Heritage registration no.: 18278/6-619
Kloiber, Michal; Drdácký, Miloš
2024 - Czech The survey described in this report contains the assessment of physical and mechanical properties of selected beams within timber structures of the truss and 1st floor ceiling in the state-owned castle called Hrádek u Nechanic (Fig. 1.1). The report has been elaborated based on an order placed by Projekční ateliér pro dokumentaci, průzkum a obnovu historických staveb, spol. s.r.o., headquartered Nerudova 1139, 544 01 Dvůr Králové nad Labem. The order included the demand to assess the condition of selected timber elements by Resistograph, and mainly to measure the mechanical properties that can contribute to static assessment and a design of non-intrusive renewal of the unique structures of both the truss and the ceiling. Průzkum popisovaný v této zprávě obsahuje vyhodnocení fyzikálních a mechanických vlastností vybraných nosných trámů dřevěné konstrukce krovu a stropu 1. patra státního zámku Hrádek u Nechanic (obr. 1.1). Podnětem k sepsání zprávy byla objednávka od Projekčního ateliéru pro dokumentaci, průzkum a obnovu historických staveb, spol. s.r.o., se sídlem Nerudova 1139, 544 01 Dvůr Králové nad Labem. Objednávka obsahovala požadavek na posouzení stavu vybraných dřevěných prvků pomocí přístroje Resistograph a především měření mechanických vlastností, které mohou přispět ke statickému posouzení a návrhu šetrné obnovy unikátní konstrukce krovu a stropu. Keywords: timber structures; truss; ceiling; state-owned castle; timber mechanical properties Available at various institutes of the ASCR Assessment of the condition and measuring of properties of the truss and 1st floor ceiling timber structures in the state-owned castle Hrádek u Nechanic, National Cultural Heritage registration no.: 18278/6-619

The survey described in this report contains the assessment of physical and mechanical properties of selected beams within timber structures of the truss and 1st floor ceiling in the state-owned ...

Kloiber, Michal; Drdácký, Miloš
Ústav teoretické a aplikované mechaniky, 2024

The U.S. low-wage structure: a McWage comparison
Ashenfelter, O.; Jurajda, Štěpán
2024 - English Thanks to standardized work protocol and technology of McDonald’s restaurants, the hourly wage of McDonald’s Basic Crew enables wage comparisons under near-identical skill inputs and hedonic job conditions. McWages capture labor costs in entry-level jobs, while the Big Macs (earned) Per Hour (BMPH) index measures corresponding purchasing power of wages. We document large and growing geographical wage differences in standardized jobs using data covering most U.S. counties during 2016-2023. Before the Covid-19 pandemic, there was no BMPH growth where minimum wages stayed constant, but the pandemic wage increase, which diminished the importance of minimum wages, was stronger in these areas. Keywords: wage comparisons; labor costs; purchasing power Fulltext is available at external website. The U.S. low-wage structure: a McWage comparison

Thanks to standardized work protocol and technology of McDonald’s restaurants, the hourly wage of McDonald’s Basic Crew enables wage comparisons under near-identical skill inputs and hedonic job ...

Ashenfelter, O.; Jurajda, Štěpán
Národohospodářský ústav, 2024

Development of Polymeric Enantioselective Membranes
Čížek, Jan
2024 - English Enantiomers are molecules that share the same chemical formula but in space form mirror images of each other. Their reactions with other chiral molecules can be remarkably different, which is crucial mainly for pharmaceuticals and agrochemicals. However, industrialscale synthetic production of enantiomerically pure compounds is not always available. Therefore, the need for pure enantiomeric compounds drives the development and research on various separation methods. However, most methods used on the industrial scale are limited to specific compounds (diastereomeric recrystallization) or generally difficult and/or expensive to scale up (chromatography-related methods). Separation of enantiomers using membranes is promising\nthanks to the easy scalability and continuous operation of membrane processes. Various ideas about how the enantioselective membranes should look like have been published in the last thirty years. The mechanism of enantiomeric separation on a membrane is, however, highly specific, and still requires extensive research. In this work, four types of enantioselective polymeric membranes are presented. Available in a digital repository NRGL Development of Polymeric Enantioselective Membranes

Enantiomers are molecules that share the same chemical formula but in space form mirror images of each other. Their reactions with other chiral molecules can be remarkably different, which is crucial ...

Čížek, Jan
Ústav chemických procesů, 2024

Synthesis of Fluorinated Methyl β-Lactosides
Krčil, Aleš
2024 - English In my contribution, I will describe the synthesis of a complete series of mono-deoxyfluorinated methyl β-lactosides (1–7). Their affinity towards hgals will be determined by analytical method ELISA. The synthesis relies on monosaccharide building blocks, which serves as key intermediates that are transformed into the target products through glycosylation followed by final deprotection steps. Keywords: flurinated carbohydrates; galectin; deoxyfluorination Available in a digital repository NRGL Synthesis of Fluorinated Methyl β-Lactosides

In my contribution, I will describe the synthesis of a complete series of mono-deoxyfluorinated methyl β-lactosides (1–7). Their affinity towards hgals will be determined by analytical method ELISA. ...

Krčil, Aleš
Ústav chemických procesů, 2024