An observation on laser surface hardened steels - wear and dynamical contact stress characteristics

Bakalářská práce je rozdělena do dvou částí, teoretické a experimentální. Teoretická část se zabývá obecným tepelným zpracováním ocelí, technologií povrchového kalení a to především technologii indukčního povrchového kalení a laserového povrchového kalení. Experimentální část zkoumá velikost opotřebení povrchu povrchově kalených ocelí vybranými zkouškami. Dále se snaží vystihnout závislost opotřebení povrchu na tepelném zpracování základního materiálu před povrchovým kalením.Katedra materiálu a strojírenské metalurgieObhájenoThe bachelor´s thesis is divided into two parts ? theoretical and experimental. The theoretical part is focused on common ways of heat treatment and the vast majority is devoted to laser surface hardening technology and induction hardening technology. Firstly, the experimental part evaluates a volume wear of surface hardened steels. Secondly, it makes a description of a surface wear influential in heat treatment of basic material before surface hardening process

Fifty Shades of the Harlequin Ladybird and a Sexually Transmitted Fungus.

The ectoparasitic fungus Hesperomyces virescens was studied on its invasive host, the harlequin ladybird Harmonia axyridis, in the Czech Republic. A primary aim was to examine the relationship between fungal infection and elytral coloration of the ladybird. Furthermore, the role of host sex and mating status of females were analyzed. Beetles (n = 1,102) were sampled during autumn migration, and then sexed, weighed, and screened for infection. Females were dissected for detection of sperm in their spermathecae. Ladybirds were sorted according to color form and absorbance spectrophotometry was used to quantify carotenoid contents in their elytra. In individuals of the nonmelanic succinea form, the degree of melanization was measured using digital photographs and putative age groups were estimated based on background color of elytra. Sexual differences in infection patterns indicated transmission during copulation: males were infected mostly on elytra and venter, and females had infection almost exclusively on elytra. Mated females had higher infection rate than virgins. There was no influence of genetic color form on the fungal infection. Putative age groups (visual sorting to yellow, orange, and red) correlated with fungal infection. Infected individuals had elevated elytral carotenoid levels in comparison to uninfected individuals, which could be explained by host age. Infection-free succinea beetles were extensively melanized because they emerged later in the season at lower temperatures which induced melanization. Overall, we highlight that H. axyridis is a multivoltine species whose age, if not taken into account in ecophysiological studies, might present a considerable confounding factor

Effect of laser cladding parameters on the corrosion properties of the cladding

Diplomová práce řeší problematiku návrhu vhodných procesních parametrů technologie laser cladding pro navařování korozivzdorných materiálů. Cílem je stanovit vhodné procesní parametry, které zaručí korozní odolnost navařených korozivzdorných materiálů. Práce se dále zabývá příčinou korozního napadení korozivzdorných návarů.Katedra materiálu a strojírenské metalurgieObhájenoThis thesis is focused on finding the appropriate process parameters for cladding corrosion resistance coatings prepared by laser cladding technology. The aim is to determine the appropriate process parameters, which ensure corrosion resistance for cladded coatings. The thesis also observes mechanism of corrosion of the clads

An observation on laser surface hardened steels - wear and dynamical contact stress characteristics

Bakalářská práce je rozdělena do dvou částí, teoretické a experimentální. Teoretická část se zabývá obecným tepelným zpracováním ocelí, technologií povrchového kalení a to především technologii indukčního povrchového kalení a laserového povrchového kalení. Experimentální část zkoumá velikost opotřebení povrchu povrchově kalených ocelí vybranými zkouškami. Dále se snaží vystihnout závislost opotřebení povrchu na tepelném zpracování základního materiálu před povrchovým kalením.Katedra materiálu a strojírenské metalurgieObhájenoThe bachelor´s thesis is divided into two parts ? theoretical and experimental. The theoretical part is focused on common ways of heat treatment and the vast majority is devoted to laser surface hardening technology and induction hardening technology. Firstly, the experimental part evaluates a volume wear of surface hardened steels. Secondly, it makes a description of a surface wear influential in heat treatment of basic material before surface hardening process

Ventilation in a cultural center

Tato práce je zaměřena na návrh vzduchotechniky v kulturním domě v Úsobí. Cílem této práce je porovnání dvou druhů distribuce vzduchu do místnosti - směšování a zaplavování. Dle požadavků vnějšího prostředí bylo navrženo množství větracího vzduchu a koncepce větrání. Pro obě varianty distribuce vzduchu byl dále navržen potrubní systém, distribuční prvky a vzduchotechnická jednotka, včetně napojení jednotky na ostatní systémy. Byla zpracována výkresová dokumentace, technická zpráva a výkaz prvků. Výsledkem práce je objektivní porovnání obou druhů distribuce vzduchu, podložené výkresovou dokumentací a podrobnými technickými informacemi. Výsledky této práce umožňují čtenáři lépe pochopit výhody i nevýhody obou systémů.This work is focused on proposal of ventilation system in cultural center in Úsobí. An object of this study is comparison of two methods of air distribution to interior - mixing and displacement. According to the requirements of the external environment it was proposed amount of ventilation air and ventilation concept. For both methods of air distribution was also designed ducting, air diffusers and air-conditioning unit, including connecting the unit to other systems. Drawing documentation, technical report and the list of elements were worked out. The result of the study is an objective comparison of the two types of air distribution, supported by drawings and detailed technical information. The effect of this study is to allow the reader to better understand the advantages and disadvantages of both systems

Global early replication disrupts gene expression and chromatin conformation in a single cell cycle.

BACKGROUND: The early embryonic divisions of many organisms, including fish, flies, and frogs, are characterized by a very rapid S-phase caused by high rates of replication initiation. In somatic cells, S-phase is much longer due to both a reduction in the total number of initiation events and the imposition of a temporal order of origin activation. The physiological importance of changes in the rate and timing of replication initiation in S-phase remains unclear. RESULTS: Here we assess the importance of the temporal control of replication initiation using a conditional system in budding yeast to drive the early replication of the majority of origins in a single cell cycle. We show that global early replication disrupts the expression of over a quarter of all genes. By deleting individual origins, we show that delaying replication is sufficient to restore normal gene expression, directly implicating origin firing control in this regulation. Global early replication disrupts nucleosome positioning and transcription factor binding during S-phase, suggesting that the rate of S-phase is important to regulate the chromatin landscape. CONCLUSIONS: Together, these data provide new insight into the role of the temporal control of origin firing during S-phase for coordinating replication, gene expression, and chromatin establishment as occurs in the early embryo.AICR 10-0908, Wellcome Trust 107056/Z/15/Z, Cancer Research UK C15873/A12700 and Gurdon Institute funding (Cancer Research UK C6946/A14492, Wellcome Trust 092096). The first author was funded by the BBSRC BB/M011194/1 and a Cambridge Trust scholarship

New fluorescent auxin derivatives : anti-auxin activity and accumulation patterns in Arabidopsis thaliana

Auxin belongs among major phytohormones and governs multiple aspects of plant growth and development. The establishment of auxin concentration gradients, determines, among other processes, plant organ positioning and growth responses to environmental stimuli. Herein we report the synthesis of new NBD- or DNS-labelled IAA derivatives and the elucidation of their biological activity, fluorescence properties and subcellular accumulation patterns in planta. These novel compounds did not show auxin-like activity, but instead antagonized physiological auxin effects. The DNS-labelled derivatives FL5 and FL6 showed strong anti-auxin activity in roots and hypocotyls, which also occurred at the level of gene transcription as confirmed by quantitative PCR analysis. The auxin antagonism of our derivatives was further demonstrated in vitro using an SPR-based binding assay. The NBD-labelled compound FL4 with the best fluorescence properties proved to be unsuitable to study auxin accumulation patterns in planta. On the other hand, the strongest anti-auxin activity possessing compounds FL5 and FL6 could be useful to study binding mechanisms to auxin receptors and for manipulations of auxin-regulated processes

ABP1–TMK auxin perception for global phosphorylation and auxin canalization

The phytohormone auxin triggers transcriptional reprogramming through a well-characterized perception machinery in the nucleus. By contrast, mechanisms that underlie fast effects of auxin, such as the regulation of ion fluxes, rapid phosphorylation of proteins or auxin feedback on its transport, remain unclear1–3. Whether auxin-binding protein 1 (ABP1) is an auxin receptor has been a source of debate for decades1,4. Here we show that a fraction of Arabidopsis thaliana ABP1 is secreted and binds auxin specifically at an acidic pH that is typical of the apoplast. ABP1 and its plasma-membrane-localized partner, transmembrane kinase 1 (TMK1), are required for the auxin-induced ultrafast global phospho-response and for downstream processes that include the activation of H+-ATPase and accelerated cytoplasmic streaming. abp1 and tmk mutants cannot establish auxin-transporting channels and show defective auxin-induced vasculature formation and regeneration. An ABP1(M2X) variant that lacks the capacity to bind auxin is unable to complement these defects in abp1 mutants. These data indicate that ABP1 is the auxin receptor for TMK1-based cell-surface signalling, which mediates the global phospho-response and auxin canalization

Parasites of Harmonia axyridis: current research and perspectives

Harmonia axyridis (Coleoptera: Coccinellidae) has been introduced widely for biological control of agricultural pests. Harmonia axyridis has established in four continents outside of its native range in Asia and it is considered an invasive alien species (IAS). Despite a large body of work on invasion ecology, establishment mechanisms of IAS and their interactions with natural enemies remain open questions. Parasites, defined as multicellular organisms that do not directly kill the host, could potentially play an important role in regulating host populations. This study presents a review of the parasites of H. axyridis, discussing their distributions and effects on host populations across the host’s native and invasive range. These parasites are: Hesperomyces virescens Thaxt. fungi, Coccipolipus hippodamiae (McDaniel and Morrill) mites, and Parasitylenchus bifurcatus Poinar and Steenberg nematodes