Cranktrain Balancing Analysis of Low-displacement Tractor Engine

Cílem této diplomové práce je určení sil působících v klikovém mechanismu nového motoru od firmy Zetor, zhodnocení stavu vyvážení, návrh úpravy vyvažovacích jednotek, výpočet modální analýzy, napěťové analýzy a deformační kontrola. Obsahem práce je také vytvoření technické dokumentace k nově upraveným vyvažovacím hřídelům.The purpose of this thesis is determinate the forces in crankshaft mechanism acting on new design engine from company Zetor, assessment of the state of balance, design modifications balancing units, calculation of modal analysis, stress analysis and strain control. The content of the work is the creation of technical documentation for the newly modified balancer shafts.

Present Trends is Power Increasing of CI and SI Engines

Tato bakalářská práce obsahuje historii a způsoby přeplňování vznětových a zážehových motorů. V kapitolách jsou stručně rozepsány výhody a nevýhody vybraných metod, konstrukční řešení a nejčastější použití v praxi. Poslední část bakalářské práce je zaměřena na návrhový výpočet turbodmychadla.This bachelor’s thesis contains history and ways of turbocharging diesel and ignition engines. In the chapters are briefly itemized the advantages and disadvantages of various methods, design solutions and most often used in practice. The last part of this thesis focuses on the calculation of the turbocharger.

Web System for Accounting Company

Cílem této práce je vytvořit funkční prototyp informačního systému pro účetní firmu. Systém bude umět zaznamenávat provedené činnosti, pomocí nich vystavovat faktury a zjišťovat pomocí statistických údajů výkonnost zaměstnanců.Scope of this thesis is to create a working protype of inforamtion system for accounting company. The system will be able to record employee's activity, use these records to issue an invoice, and state employee's efficiency using statistics.

Words apart: Standardizing forestry terms and definitions across European biodiversity studies

Forest biodiversity studies conducted across Europe use a multitude of forestry terms, often inconsistently. This hinders the comparability across studies and makes the assessment of the impacts of forest management on biodiversity highly context-dependent. Recent attempts to standardize forestry and stand description terminology mostly used a top-down approach that did not account for the perspectives and approaches of forest biodiversity experts. This work aims to establish common standards for silvicultural and vegetation definitions, creating a shared conceptual framework for a consistent study on the effects of forest management on biodiversity. We have identified both strengths and weaknesses of the silvicultural and vegetation information provided in forest biodiversity studies. While quantitative data on forest biomass and dominant tree species are frequently included, information on silvicultural activities and vegetation composition is often lacking, shallow, or based on broad and heterogeneous classifications. We discuss the existing classifications and their use in European forest biodiversity studies through a novel bottom-up and top-driven review process, and ultimately propose a common framework. This will enhance the comparability of forest biodiversity studies in Europe, and puts the basis for effective implementation and monitoring of sustainable forest management policies. The standards here proposed are potentially adaptable and applicable to other geographical areas and could be extended to other forest interventions. Forest management Multi-taxon Terminology Silviculture Data harmonizationpublishedVersio

Where are we now with European forest multi-taxon biodiversity and where can we head to?

The European biodiversity and forest strategies rely on forest sustainable management (SFM) to conserve forest biodiversity. However, current sustainability assessments hardly account for direct biodiversity indicators. We focused on forest multi-taxon biodiversity to: i) gather and map the existing information; ii) identify knowledge and research gaps; iii) discuss its research potential. We established a research network to fit data on species, standing trees, lying deadwood and sampling unit description from 34 local datasets across 3591 sampling units. A total of 8724 species were represented, with the share of common and rare species varying across taxonomic classes: some included many species with several rare ones (e.g., Insecta); others (e.g., Bryopsida) were represented by few common species. Tree-related structural attributes were sampled in a subset of sampling units (2889; 2356; 2309 and 1388 respectively for diameter, height, deadwood and microhabitats). Overall, multitaxon studies are biased towards mature forests and may underrepresent the species related to other developmental phases. European forest compositional categories were all represented, but beech forests were overrepresented as compared to thermophilous and boreal forests. Most sampling units (94%) were referred to a habitat type of conservation concern. Existing information may support European conservation and SFM strategies in: (i) methodological harmonization and coordinated monitoring; (ii) definition and testing of SFM indicators and thresholds; (iii) data-driven assessment of the effects of environmental and management drivers on multi-taxon forest biological and functional diversity, (iv) multi-scale forest monitoring integrating in-situ and remotely sensed information. Forest biodiversity Multi-taxon Sustainable management Biodiversity conservation Forest stand structurepublishedVersio

The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests

Heatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-temporal resolution dendrometer data from 21 species across 53 sites. Relative to the two preceding years, annual stem growth was not consistently reduced by the 2018 heatwave but stems experienced twice the temporary shrinkage due to depletion of water reserves. Conifer species were less capable of rehydrating overnight than broadleaves across gradients of soil and atmospheric drought, suggesting less resilience toward transient stress. In particular, Norway spruce and Scots pine experienced extensive stem dehydration. Our high-resolution dendrometer network was suitable to disentangle the effects of a severe heatwave on tree growth and desiccation at large-spatial scales in situ, and provided insights on which species may be more vulnerable to climate extremes