Strength Analysis of Steel Construction of Washing Box

V této bakalářské práci se zabývám výpočtem konstrukce ruční myčky. Na práci spolupracuji s firmou PETROCard, s.r.o. Cílem této práce je provést statickou analýzu zadané ruční myčky, počítám se zatížením sněhem i větrem, které určuji z platných evropských norem. V další části práce budu provádět změny na konstrukci s účelem optimalizace. Cílem optimalizace je úspora materiálu a nepřekročení maxim mechanických vlastností. Pro výpočet budu používat metodu konečných prvků v softwaru Workbench 18.2.In this bachelor thesis, I focus on the calculation of the construction of a hand car wash. On this thesis, I cooperate with a company PETROCard, s.r.o. The goal of this thesis is to perform statical analysis of the assigned car wash, I count with snow load even wind load, which I determine from valid Europian standards. In the next part of the thesis, I will perform changes on the construction with the aim of the optimization. The optimization goal is material saving and not exceeding the maximum of mechanical properties. For calculation, I will use finite element method in the software Ansys Workbench 18.2.330 - Katedra aplikované mechanikyvýborn

Stress-Strain Behavior of Steel Specimen Manufactured by 3D Print Technology

V této diplomové práci se zabývám výpočtem průběhu 3D tisku ocelového vzorku. Na práci spolupracuji s laboratoří Protolab. Cílem této práce je provést napěťově-deformační analýzu u různých typů vzorků. Jedná se o plný vzorek, dutý vzorek a vzorky s lattice strukturou. V další části práce budu mé dosažené výsledky porovnávat s výsledky z experimentálního měření a porovnávat výhody a nevýhody jednotlivých typů vzorků. Pro výpočet budu používat metodu konečných prvků v softwaru Ansys Workbench 2020 R1.In this diploma thesis, I focus on the calculation of the 3D printing process of a steel sample. I work with the Protolab laboratory on my work. This work aims to perform a stress-strain analysis of various types of samples. It is a solid sample, a hollow sample, and samples with a lattice structure. In the next part of the work, I will compare my achieved results with the results from experimental measurements and compare the advantages and disadvantages of individual types of samples. I will use the finite element method in the Ansys Workbench 2020 R1 software for the calculation.330 - Katedra aplikované mechanikyvýborn

Molecular analyses reveal consistent food web structure with elevation in rainforest Drosophila – parasitoid communities

The analysis of interaction networks across spatial environmental gradients is a powerful approach to investigate the responses of communities to global change. Using a combination of DNA metabarcoding and traditional molecular methods we built bipartite Drosophila – parasitoid food webs from six Australian rainforest sites across gradients spanning 850 m in elevation and 5°C in mean temperature. Our cost-effective hierarchical approach to network reconstruction separated the determination of host frequencies from the detection and quantification of interactions. The food webs comprised 5–9 host and 5–11 parasitoid species at each site, and showed a lower incidence of parasitism at high elevation. Despite considerable turnover in the relative abundance of host Drosophila species, and contrary to some previous results, we did not detect significant changes to fundamental metrics of network structure including nestedness and specialisation with elevation. Advances in community ecology depend on data from a combination of methodological approaches. It is therefore especially valuable to develop model study systems for sets of closely-interacting species that are diverse enough to be representative, yet still amenable to field and laboratory experiments

Parasitoid communities attacking externally feeding folivorous Lepidoptera in New Guinea rainforest

The host - parasitoid community of externally feeding folivorous Lepidoptera and their parasitoids was studied on 45 focal tree species in a New Guinea rainforest. The patterns of parasitation rate, parasitoid species richness and parasitoid host specificity are described

Caterpillar - parasitoid food webs in New Guinea rainforest

The thesis establishes baseline ecological parameters (parasitism rate, host specificity, and food web structure) for tropical external folivore - parasitoid food webs and finds the parasitoids strongly host specific. Further, it presents a new method for molecular detection of herbivore - parasitoid relationships, and describes some of the studied species to ensure long-term value of the ecological data

Data from: Symbionts modify interactions between insects and natural enemies in the field

Eukaryotes commonly host communities of heritable symbiotic bacteria, many of which are not essential for their hosts' survival and reproduction. There is laboratory evidence that these facultative symbionts can provide useful adaptations, such as increased resistance to natural enemies. However, we do not know how symbionts affect host fitness when the latter are subject to attack by a natural suite of parasites and pathogens. Here, we test whether two protective symbionts, Regiella insecticola and Hamiltonella defensa, increase the fitness of their host, the pea aphid (Acyrthosiphon pisum), under natural conditions. We placed experimental populations of two pea aphid lines, each with and without symbionts, in five wet meadow sites to expose them to a natural assembly of enemy species. The aphids were then retrieved and mortality from parasitoids, fungal pathogens and other causes assessed. We found that both Regiella and Hamiltonella reduce the proportion of aphids killed by the specific natural enemies against which they have been shown to protect in laboratory and cage experiments. However, this advantage was nullified (Hamiltonella) or reversed (Regiella) by an increase in mortality from other natural enemies and by the cost of carrying the symbiont. Symbionts therefore affect community structure by altering the relative success of different natural enemies. Our results show that protective symbionts are not necessarily advantageous to their hosts, and may even behave more like parasites than mutualists. Nevertheless, bacterial symbionts may play an important role in determining food web structure and dynamics

Experimental warming influences species abundances in a Drosophila host community through direct effects on species performance rather than altered competition and parasitism.

Global warming is expected to have direct effects on species through their sensitivity to temperature, and also via their biotic interactions, with cascading indirect effects on species, communities, and entire ecosystems. To predict the community-level consequences of global climate change we need to understand the relative roles of both the direct and indirect effects of warming. We used a laboratory experiment to investigate how warming affects a tropical community of three species of Drosophila hosts interacting with two species of parasitoids over a single generation. Our experimental design allowed us to distinguish between the direct effects of temperature on host species performance, and indirect effects through altered biotic interactions (competition among hosts and parasitism by parasitoid wasps). Although experimental warming significantly decreased parasitism for all host-parasitoid pairs, the effects of parasitism and competition on host abundances and host frequencies did not vary across temperatures. Instead, effects on host relative abundances were species-specific, with one host species dominating the community at warmer temperatures, irrespective of parasitism and competition treatments. Our results show that temperature shaped a Drosophila host community directly through differences in species' thermal performance, and not via its influences on biotic interactions

SymbiontFieldExperimentData

Data from field exposure experiment

Performance of DNA metabarcoding, standard barcoding, and morphological approach in the identification of host–parasitoid interactions

<div><p>Understanding interactions between herbivores and parasitoids is essential for successful biodiversity protection and monitoring and for biological pest control. Morphological identifications employ insect rearing and are complicated by insects’ high diversity and crypsis. DNA barcoding has been successfully used in studies of host–parasitoid interactions as it can substantially increase the recovered real host–parasitoid diversity distorted by overlooked species complexes, or by species with slight morphological differences. However, this approach does not allow the simultaneous detection and identification of host(s) and parasitoid(s). Recently, high-throughput sequencing has shown high potential for surveying ecological communities and trophic interactions. Using mock samples comprising insect larvae and their parasitoids, we tested the potential of DNA metabarcoding for identifying individuals involved in host–parasitoid interactions to different taxonomic levels, and compared it to standard DNA barcoding and morphological approaches. For DNA metabarcoding, we targeted the standard barcoding marker cytochrome oxidase subunit I using highly degenerate primers, 2*300 bp sequencing on a MiSeq platform, and RTAX classification using paired-end reads. Additionally, using a large host–parasitoid dataset from a Central European floodplain forest, we assess the completeness and usability of a local reference library by confronting the number of Barcoding Index Numbers obtained by standard barcoding with the number of morphotypes. Overall, metabarcoding recovery was high, identifying 92.8% of the taxa present in mock samples, and identification success within individual taxonomic levels did not significantly differ among metabarcoding, standard barcoding, and morphology. Based on the current local reference library, 39.4% parasitoid and 90.7% host taxa were identified to the species level. DNA barcoding estimated higher parasitoid diversity than morphotyping, especially in groups with high level of crypsis. This study suggests the potential of metabarcoding for effectively recovering host–parasitoid diversity, together with more accurate identifications obtained from building reliable and comprehensive reference libraries, especially for parasitoids.</p></div