Mendel University in Brno

Mendelu Repository
Not a member yet
    273 research outputs found

    Physical Properties of Silver Fir (Abies alba L.) Wood Cladding Modified by Traditional Japanese Charring Method

    Get PDF
    Silver fir (Abies alba L.) wood samples were charred on one surface using an enhanced version of the traditional Japanese Yakisugi method. The 15 charred boards obtained from five charring chimneys were divided into three different zones and investigated for their physical properties. The density profile, water absorption after 24 h of water submersion, and Brinell hardness were analyzed. In general, the temperature-time regime, which causes inside surface carbonization, was more evident at the bottom than at the top of the chimney. The density profile of the specimens revealed that the surface charring treatment decreased the surface density of the wood significantly. A gradient was visible from 383 kg/m2 at the bottom to 424 kg/m2 at the top. Water absorption measurements showed that a thicker carbonized layer could take up more water as a result of increased porosity. While 3,684 g/m2 were absorbed at the bottom, the top accounted for only 2,533 g/m2. Furthermore, with increasing thickness of the charred layer, the hardness gradually decreased. The average of the charred specimens reached only 3.2% of the hardness of the uncharred back side of the specimens.O

    Competitiveness of Individuals in the Labour Market During the Pandemic

    Get PDF
    The global COVID-19 pandemic has changed the behaviour of individuals and companies. This study aims to determine changes in the labour market behaviour of economically active individuals in the context of the pandemic and to identify competitive segments in this period. For this purpose, a representative survey (n = 3079) conducted in the Czech Republic was used. The paper's contribution is a perspective of individuals' behaviour and their perception of the situation. Based on subjective perceptions, respondents provided an assessment of their living situation before and during the pandemic, expressing their opinion on the importance of selected aspects of quality of life, such as their health, active social contacts, creation of financial savings, ability to pay bills, leisure time and coping with stressful situations. The results of a Wilcoxon test showed that individuals re-evaluated each aspect of life and that the pandemic changed the importance for all of them (except leisure time). This change is also reflected in their psyche, attitude towards work organisation, digitalisation and other factors; these were applied in a cluster analysis, which resulted in the identification of three segments in the group of employees in the labour market (competitive individuals, surviving individuals and those reluctant to respond to change). For the group of entrepreneurs, two segments emerged (flexible and loss-creating), while for the unemployed group, the typical segment can be described as dissatisfied and Covid victims. The names of these segments indicate their behaviour and provide possibilities for future use.O

    Phytophthora, Nothophytophthora and Halophytophthora diversity in rivers, streams and riparian alder ecosystems of Central Europe

    Get PDF
    Waterways are ideal pathways for Phytophthora dispersal and potential introduction to terrestrial ecosystems. While many Phytophthora species from phylogenetic clades 6, 9 and 10 are predominant oomycetes in watercourses due to their adaptation to a lifestyle as saprotrophs and opportunistic pathogens of riparian plants, species from clades 2, 7 and 8 are predominantly soil- or airborne using aquatic habitats as temporal niches for spreading and invading terrestrial sites along the watercourses. In contrast to forest ecosystems, knowledge of Phytophthora diversity in watercourses in Central Europe is limited. Between 2014 and 2019 extensive surveys of streams and rivers were undertaken across Austria, in South Moravia, Czech Republic and Žilina province, Slovakia to unveil the diversity and distribution of Phytophthora and related oomycetes. In addition, in Austria riparian forests of black alder (Alnus glutinosa) and grey alder (A. incana) in lowlands and in the Alps were examined. A variety of Phytophthora species from clades 2, 6, 7, 8, 9 and 10 were isolated, with clade 6 species showing the widest distribution and abundance. Furthermore, interspecific clade 6 hybrids and other oomycetes such as Halophytophthora fluviatilis and undescribed Nothophytophthora spp. were also obtained. In riparian alders, symptoms of Phytophthora infections were associated with species from the P. x alni complex and P. plurivora. Phytophthora plurivora was most common in alder stands whereas P. uniformis was the oomycete species occurring at the highest altitude in alpine riparian areas.OA-hybri

    Comparison of Methods for Estimating Damage by Wild Ungulates on Field Crops

    Get PDF
    High numbers of large ungulates are locally accompanied by high levels of damage to field crops, causing economic losses and increased costs for the protection of agricultural fields. Quantifying the levels of damage can be problematic, with the degree of accuracy depending on the method used. The aim of this study was to compare the accuracy, workload and cost of four methods commonly used for estimating damage to wheat fields caused by large ungulates (esp. wild boar) in the Czech Republic. The results suggest that the manual processing of aerial photographs ("Uncrewed Aerial Systems [UAS] with Operator Delineation Method") was very laborious and the least accurate method, with a high risk of error. In comparison, the automatic evaluation of aerial images ("UAS Crop Height Method") and the "Ground-Based Assessment" both provided similar results when carefully analyzed and were equally demanding. The "Yield Method", comparing the net yield from damaged and undamaged areas, provided the same result of assessment and was the least laborious, although it does require the existence of comparable areas and for the conditions to be created in advance before the method is used. Equivalent results were achieved by the UAS Crop Height Method, which we recommend using in cases where the Yield Method cannot be applied.O

    Intervention analysis of COVID-19 pandemic impact on timber price in selected markets

    Get PDF
    Using intervention analysis and time series of roundwood prices from ten European and North American countries, we analyzed the impact of the COVID-19 pandemic on the movement of timber prices. The study material consists of forty-six quarterly time series prices of logs and pulp, both softwood and hardwood, covering the period 2005-2022. During the Covid-19 pandemic period (2020:Q1-2020:Q4), softwood log prices mostly underwent declines, with the changes being the largest in Slovakia (MINUS SIGN 35%), the Czech Republic (MINUS SIGN 24%) and Austria (MINUS SIGN 24%), slightly smaller in the United States (MINUS SIGN 19%), Poland (MINUS SIGN 17%), Slovenia (MINUS SIGN 12%) and Germany (MINUS SIGN 11%) while no significant price changes were recorded in Finland and Sweden. In Canada and the United States, sharp price declines occurred earlier (2020:Q1 and 2020:Q2, respectively), while in Europe, significant price declines occurred later and lasted longer. In the post-pandemic COVID-19 period, prices increased, but in most cases, the shift was not statistically significant compared to the pre-pandemic period. Softwood pulp prices were subject to much less change, with a significant increase only in Slovakia and Poland. In contrast, no significant changes were observed in the price of both log and pulpwood hardwood during the COVID-19 pandemic.OA-hybri

    A different approach to hop growing

    Get PDF
    The current study aimed to examine how various growers in the Czech Republic hop-growing regions approached the production of hops (Saaz variety). The work also keeps track of how different growers approach fertilization and nutrition, as well as how often plant protection chemicals containing these ingredients are used. The Saaz hop variety samples from the primary Czech hop-growing regions, gathered in 2020 and 2021, were assessed. The average spindle length (14-18 mm), average number of spindle segments (9.3-11.9 pcs/needle) and conductometric parameters (2.7-4.7% w/w) in the samples were identified.O

    Spatial distribution of saproxylic beetles on trunks of standing Scots pine trees

    Get PDF
    The spatial distribution of saproxylic beetles landing and climbing stems of 12 grown and healthy Scots pine trees (Pinus sylvestris L.) was examined in detail during a 3-year trial. The beetles were sampled using sticky traps attached to the tree trunk at three tree parts (i.e., the trunk base, middle part of the trunk, and trunk in crown). Each tree part was sampled using two sticky traps facing opposite cardinal directions (north and south). In total, 4063 individuals representing 169 taxa of saproxylic beetles were yielded in the 1405 obtained samples. Remarkable interstrata diversification of saproxylic beetle assemblages reflecting distribution of breeding substrates in the forest stand was observed. Overall, species richness decreased considerably from the trunk base to the crown, with intermediate values for the middle part of the trunk. However, the abundance of mycetophages and saproxylophages decreased from the trunk base to the crown, with xylophages being the most abundant in the tree crown. The cardinal direction exhibited overall weak effects on abundance, species richness, and composition, but the occurrence of a few particular species was significantly associated with the south (13 species) or north (3 species) facing part of the trunk. Our results suggest that primary attraction and random landing strategies are combined during the substrate selection by many species. High variability in the importance of the studied explanatory variables was observed among taxa, which shows how the species composition recorded in any study might alter its general outcomes.OA-hybri

    Value Creation with Digital Twins: Application-Oriented Conceptual Framework and Case Study

    Get PDF
    The internet of things, digital twins of smart connected products, and thereby enabled smart services are topics of great interest and have been gaining traction for many years. However, many questions concerning the application-oriented usage of digital twins still need to be scrutinized. Therefore, this paper examines the question of an application-oriented framework for value creation with digital twins using design science research approaches. A conceptual reference framework is presented based on earlier research and iteratively developed within workshops with three companies. The framework incorporates primary dimensions of external and internal value creation and data resources. Further, it discusses the product life cycle, the real-world counterpart, value creation in the ecosystem, and the generational aspect of the digital twins. Furthermore, applying the framework to a use case with an industrial research partner helps to show the contributions to the industrial sector. The framework provides utility to practitioners as a means of creating a common sense in interdisciplinary teams, communicating digital twin projects to internal and external stakeholders, and as a toolbox for specific challenges concerning digital twins. In addition, the framework distinguishes itself from existing approaches by including the service ecosystem and its actors while considering the principles of product life cycle management. Therefore, using the framework in other use cases will test the approach on different industries and products. Furthermore, there is a need to develop approaches for implementing and developing an existing case.O

    Forestry and wood technology research and education network for climate change adaptation strategies and ASFORCLIC - HORIZON 2020 project

    Get PDF
    Seven European universities and research institutions from four countries agreed to collaborate on the ASFORCLIC - HORIZON 2020 project to support the ambitious goals of raising the leading institution's MENDELU research profile and strengthening its research excellence in the highly demanding field of assessing the impact of global climate change on forests and the bio-based sector. The ASFORCLIC consortium evaluates possible risk factors, predicts their evolution, and develops adaption strategies for future applications to monitor the impact of global climate change on central European forestry, particularly Czech forestry. Facing the unprecedented challenge of implementing a mobility project during the COVID-19 pandemic, the consortium used strategic approaches and augmented offerings, including successful literature seminars, writing workshops, and advanced data evaluation training largely realized through virtual platforms.O

    Sequence and phylogenetic analysis of a novel alphaendornavirus, the first virus described from the oomycete plant pathogen Phytophthora heveae

    Get PDF
    Here, we report the discovery and complete genome sequence of a novel virus, designated as "Phytophthora heveae alphaendornavirus 1" (PhAEV1), from a single isolate of the plant pathogenic oomycete Phytophthora heveae (kingdom Stramenipila) isolated from a tropical evergreen lowland rainforest in northern Vietnam. PhAEV1 was detected by both cellulose affinity chromatography of dsRNA and high-throughput sequencing of total RNA, and its presence and sequence were confirmed by RT-PCR and Sanger sequencing. The PhAEV1 genome, 12,820 nucleotides (nt) in length, was predicted to encode a single large polyprotein with the catalytic core domain of viral (superfamily 1) RNA helicase (HEL, amino acid [aa] positions 1,287-1,531), glycosyltransferase (GT, aa positions ca. 2,800-3,125), and RNA-directed RNA polymerase (RdRp, aa positions 3,875-4,112). PhAEV1 is the most similar to Phytophthora cactorum alphaendornavirus 3, sharing 39.4% and 39.1% nt and aa sequence identity, respectively. In addition to the first 5'-terminal AUG codon, three additional in-frame methionine codons were found in close proximity (nt 14-16, 96-98, and 176-178), suggesting potential additional translation initiation sites. Conserved RdRp motifs (A-E) similar to those detected in related endornaviruses were identified in PhAEV1, as well as in several previously described alphaendornaviruses from other Phytophthora species in which these motifs had not been identified previously. Phylogenetic analysis showed that PhAEV1 clusters with members of the genus Alphaendornavirus in the family Endornaviridae and is basal to two other alphaendornaviruses described from another oomycete, Phytophthora cactorum. PhAEV1 is the first virus reported in P. heveae.OA-hybri


    full texts


    metadata records
    Updated in last 30 days.
    Mendelu Repository
    Access Repository Dashboard
    Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇