Využití obnovitelných zdrojů energie v extrémních podmínkách na výzkumných stanicích v Antarktidě

Snižování energetické náročnosti a maximální využití obnovitelných zdrojů v energetickém mixu je předpokladem pro udržitelný rozvoj a minimalizaci dopadu lidské činnosti na ekosystémy. Výjimečný význam má v místech, které jsou doposud lidskou činností téměř nedotčené, jakými je též Antarktida. Jedná se o kontinent nejchladnější, s nejvyšší průměrnou nadmořskou výškou, nejnižším slunečním ozářením a současně nejméně prozkoumaný. Objem výzkumných aktivit v Antarktidě každoročně roste, vznikají nové vědecké základny, roste i počet států podílejících se na výzkumu terestrických ekosystémů Antarktidy. Využití obnovitelných zdrojů pro zajištění potřeb personálu vede ke snížení spotřeby fosilních paliv a emisí a hraje důležitou roli v ochraně zdejší přírody. Tento příspěvek popisuje současný stav, technické a ekonomické možnosti využití obnovitelných zdrojů na vědeckých stanicích v Antarktidě s ohledem na klimatické poměry a požadavky provozu. Podrobněji popisuje energetický systém na České vědecké stanici Johanna Gregora Mendela na ostrově Jamese Rosse.Snižování energetické náročnosti a maximální využití obnovitelných zdrojů v energetickém mixu je předpokladem pro udržitelný rozvoj a minimalizaci dopadu lidské činnosti na ekosystémy. Výjimečný význam má v místech, které jsou doposud lidskou činností téměř nedotčené, jakými je též Antarktida. Jedná se o kontinent nejchladnější, s nejvyšší průměrnou nadmořskou výškou, nejnižším slunečním ozářením a současně nejméně prozkoumaný. Objem výzkumných aktivit v Antarktidě každoročně roste, vznikají nové vědecké základny, roste i počet států podílejících se na výzkumu terestrických ekosystémů Antarktidy. Využití obnovitelných zdrojů pro zajištění potřeb personálu vede ke snížení spotřeby fosilních paliv a emisí a hraje důležitou roli v ochraně zdejší přírody. Tento příspěvek popisuje současný stav, technické a ekonomické možnosti využití obnovitelných zdrojů na vědeckých stanicích v Antarktidě s ohledem na klimatické poměry a požadavky provozu. Podrobněji popisuje energetický systém na České vědecké stanici Johanna Gregora Mendela na ostrově Jamese Rosse.Reduction of energy consumption and utilisation of renewable energy sources are required to achieve sustainability and to minimise the impact of human activities on ecosystems. This is especially important in landscapes untouched by human activity, such as Antarctica. Antarctica is the coldest, least explored continent with the highest average mean sea level and the lowest solar insolation. The amount of research conducted in Antarctica grows every year, new research stations are built and more countries are getting involved in research of terrestrial ecosystems. The use of renewables for research activities reduces fossil fuels consumption and emissions and protects the local environment. This article sheds light on the current situation, technical and economic options for renewable energy use at research station in Antarctica with regard to climatic conditions and operation requirements. In details it describes energy system at Johann Gregor Mendel Czech Antarctic Station on James Ross Island

Effect of extraction methods on aroma profile, antioxidant activity and sensory acceptability of specialty coffee brews

Specialty coffees from various geographical origins were processed using different extraction methods. Four extraction techniques were employed: cold brew (CB), espresso (ES), French press (FR), and aeropress (AE). The potential health benefits of coffee brews were linked to their antioxidant activity, as determined by the DPPH assay, and total polyphenol content (TPC) measured through the Folin–Ciocalteu reducing-capacity assay. The Columbia (C) espresso coffee type (omni-roasting) exhibited the highest antioxidant activity (86.31 ± 0.70) μmol/100 mL, with a TPC value of (44.41 ± 0.35) mg GAE/g. Quantitative analyses of caffeine and chlorogenic acid were conducted using high-performance liquid chromatography (HPLC). The evaluation of coffee aroma profiles involved the application of headspace solid-phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS) and was complemented by sensory analysis following the Specialty Coffee Association (SCA) standard protocol. The predominant volatile compounds found in all samples included furans, phenols, pyrazines, and terpenes. The EY espresso type (medium dark roasting) had the highest levels of most coffee volatiles. The C cold brew type (omni-roasting) was rated as the preferred coffee in terms of its sensory characteristics and flavour. In summary, ES and CB were found to be more effective extraction methods for the parameters assessed.Tomas Bata University in Zlín, TBU, (IGA/FT/2023/007); Univerzita Palackého v Olomouci, UP, (IGA_PRF_2023_024)Palacky University in Olomouc [IGA_PRF_2023_024]; Tomas Bata University in Zlin [IGA/FT/2023/007

The singing activity of the Yellowhammer (Emberiza citrinella) under traffic noise around highways

Steadily increasing human population is changing the environment in many ways. One of the most disturbing impacts is the development of anthropogenic noise pollution connected to ever-growing traffic intensity. The road network can have both positive and negative effects on biodiversity and populations. Many bird species use acoustic communication to establish and maintain their territories and for intra-pair and adult–young communication. Noise pollution can impact negatively on breeding success and biorhythm if this communication is masked by noise and the individuals must adjust their singing activity. Yellowhammer (Emberiza citrinella) is a common bird species of agricultural landscapes whose population is declining due to agricultural intensification. It is found also in habitats near highways with forest steppe-like characteristics, where it is affected by the high levels of anthropogenic noise pollution. This study aimed to determine how this species adapts to noise from highway traffic by adjusting its singing activity. The influence of locality type, immediate and long-term impact of traffic noise on the average and total length of song sequences in the birdsong, and influence on the total number of recorded song sequences during the second hour after sunrise were evaluated in this study. Our results showed that Yellowhammer’s singing activity changed in localities close to highways compared to agricultural landscape. With increasing long-term traffic intensity on highways, song duration of the Yellowhammer song was decreasing. The present traffic intensity led to later onset of dawn chorus and decreasing strophe length with increasing number of passing vehicles. Furthermore, in the agricultural landscape, Yellowhammer’s song duration increased with increasing distance from the nearest road

Habitats as predictors in species distribution models: Shall we use continuous or binary data?

The representation of a land cover type (i.e. habitat) within an area is often used as an explanatory variable in species distribution models. However, it is possible that a simple binary presence/absence of the suitable habitat might be the most important determinant of the presence/absence of some species and, thus, be a better predictor of species occurrence than the continuous parameter (area). We hypothesize that the binary predictor is more suitable for relatively rare habitats (e.g. wetlands) while for common habitats (e.g. forests) the amount of the focal habitat is a better predictor. We used the Third Atlas of Breeding Birds in the Czech Republic as the source of species distribution data and CORINE Land Cover inventory as the source of the landcover information. To test our hypothesis, we fitted generalized linear models of 32 water and 32 forest bird species. Our results show that for water bird species, models using binary predictors (presence/absence of the habitat) performed better than models with continuous predictors (i.e. the amount of the habitat); for forest species, however, we observed the opposite. Thus, future studies using habitats as predictors of species occurrences should consider the prevalence of the habitat in the landscape, and the biological role of the habitat type in the particular species' life history. In addition, performing a preliminary comparison of the performance of the binary and continuous versions of habitat predictors (e.g. using information criteria) prior to modelling, during variable selection, can be beneficial. These are simple steps that will improve explanatory and predictive performance of models of species distributions in biogeography, community ecology, macroecology and ecological conservation

Scale mismatches between predictor and response variables in species distribution modelling: A review of practices for appropriate grain selection

There is a lack of guidance on the choice of the spatial grain of predictor and response variables in species distribution models (SDM). This review summarizes the current state of the art with regard to the following points: (i) the effects of changing the resolution of predictor and response variables on model performance; (ii) the effect of conducting multi-grain versus single-grain analysis on model performance; and (iii) the role of land cover type and spatial autocorrelation in selecting the appropriate grain size. In the reviewed literature, we found that coarsening the resolution of the response variable typically leads to declining model performance. Therefore, we recommend aiming for finer resolutions unless there is a reason to do otherwise (e.g. expert knowledge of the ecological scale). We also found that so far, the improvements in model performance reported for multi-grain models have been relatively low and that useful predictions can be generated even from single-scale models. In addition, the use of high-resolution predictors improves model performance; however, there is only limited evidence on whether this applies to models with coarser-resolution response variables (e.g. 100 km2 and coarser). Low-resolution predictors are usually sufficient for species associated with fairly common environmental conditions but not for species associated with less common ones (e.g. common vs rare land cover category). This is because coarsening the resolution reduces variability within heterogeneous predictors and leads to underrepresentation of rare environments, which can lead to a decrease in model performance. Thus, assessing the spatial autocorrelation of the predictors at multiple grains can provide insights into the impacts of coarsening their resolution on model performance. Overall, we observed a lack of studies examining the simultaneous manipulation of the resolution of predictor and response variables. We stress the need to explicitly report the resolution of all predictor and response variables.Peer reviewe

Public law contracts

Diplomová práce se snaží podat ucelený náhled na institut veřejnoprávních smluv, jejichž obecná úprava vznikla teprve zákonem č. 500/2004 Sb., správní řád. Práce začíná historickým vývojem institutu veřejnoprávních smluv a následující kapitoly se věnují současnému pojetí institutu veřejnoprávních smluv, jejich členění, kontraktaci, přezkumu souladu veřejnoprávních smluv s právními předpisy, změně obsahu, výpovědi a zrušení veřejnoprávních smluv, sporům z těchto smluv vzniklých a poslední kapitoly se věnují příkladům veřejnoprávních smluv z pozitivní právní úpravy.Katedra správního právaObhájenoThe dissertation is attempting to present an integral insight into the institute of public-law contracts which was only introduced with the Act No. 500/2004 Coll., Administrative Code. The paper begins with the evolutionary history of the institute of public-law contracts and the following chapters have been devoted to the contemporary conception of the institute of public-law contracts, their compartmentalisation, entering into and reviewing the compliance of public-law contracts with the legal regulations, amendments to contents, notice and the cancellation of public-law contracts, disputes resulting from such contracts and the final chapters concentrate on examples of public-law contracts from the effective legal form

Influence of foreign private actors on political decision-making in the Czech Republic: case study of Japanese and German economic actors

Influence of non-state transnational actors on decision-making of sovereign states is one of the most important topics in the international relations discipline. Some academic approaches consider this influence as quite important. Others perceive it as only secondary. Economic actors are a specific case because they on one hand bring know-how, employment and economic growth. On the other hand, they decrease sovereignty of the host states. This thesis tries to uncover influence of the two strongest non-state transnational economic actors in the Czech Republic - German and Japanese Chambers of Commerce. The topic of lobbying of these actors in the case of lack of labor force in the Czech Republic was chosen because of its good empirics. The text also aims to test assumptions according to which bargaining power of such actors is influenced by geographical distance between the host state and home country of the transnational actor. This thesis also wants to address the general topic of influence of the transnational actors on states in the international relations, based on the findings of this case study

Increasing effectiveness of hot-dip galvanizing in the enterprise Sempra a.s. Praha, machinery works Děčín

katedra: KOM; přílohy: CD ROM; rozsah: 40Thesis summarizes information on hot-dip galvanizing technology. It deals with new developments in the process of pre-treatment and coating - composition for baths technological degreasing, pickling and zinc melt composition. The challenge is to increase the efficiency of hot-dip galvanizing operation.Práce shrnuje informace o technologii žárového zinkování. Zabývá se novými poznatky v procesu předúpravy a pokovení - složení technologických lázní pro odmaštění, moření a složení zinkové taveniny. Úkolem této práce je zvýšení efektivnosti provozu žárové zinkovny