Search Results (6)

For several years now, fruit-growers have increasingly often used pre-tensioned, pre-stressed concrete posts for supporting branches of fruit trees and suspending protective nets in order to limit damage to fruits caused by hail, wind, snow, heavy rainfall, insects and birds. Pre-tensioned, pre-stressed concrete posts most often have a trapezoidal cross-section, which is ideally suitable for mass production in a self-supporting non-dismantlable steel mould on a pre-stressing bed. Posts with 70 mm × 75 mm, 80 mm × 85 mm and 90 mm × 95 mm cross-sections are typically produced, whereas 100 mm × 120 mm and 130 mm × 140 mm posts are manufactured to order. Furthermore, it is proposed to produce hollow posts. Such posts are lighter than solid posts, but they require a more complicated production technology. This paper presents selected parts of a comparative computational–experimental analysis of solid and hollow posts. In the Building Structures Laboratory in the Building Structures Department at the Civil Engineering Faculty of the Wrocław University of Science and Technology, experimental tests of pre-stressed concrete orchard posts of 70 mm × 75 mm and 90 mm × 95 mm with solid and hollow cross-sections were carried out on a full scale. The theoretical analysis and research has shown that the resistance to bending, cracking resistance and rigidity of hollow posts (with their cross-sectional outline unchanged) will not significantly differ from those of the currently produced solid posts. At same time, material savings will be achieved. Therefore, the main task is to master the continuous moulding of hollow posts from dense plastic concrete with the simultaneous pulling out of the cores, producing longitudinal hollows in the posts. Full article

Microdochium species are harmful pathogens of winter cereals, causing snow mould and stem base diseases such as root rot. With changing climatic conditions, including prolonged wet autumns and mild winters, addressing pathogens that thrive at low positive temperatures has become increasingly important. Integrated strategies, including optimized sowing times, resistant cultivars, and the use of seed treatment fungicides have been suggested as effective approaches to mitigate Microdochium-induced damage. Field trials were conducted between 2021 and 2024 using five winter wheat cultivars treated with different seed treatment fungicides and sown at either optimal or delayed sowing times. Laboratory analyses identified Microdochium spp. as the dominant pathogens on the stem base across all trial years. Disease severity assessments indicated that seed treatment fungicides were generally effective against root rot, with products containing fludioxonil and SDHI group fungicides delivering the best performance. While disease pressure varied between optimal and late sowing experiments, late-sown winter wheat exhibited slightly reduced damage in most years. Additionally, some of the tested winter wheat cultivars demonstrated better performance against Microdochium spp. damage compared to others, highlighting the importance of selecting resistant cultivars. This study provides valuable insights into the control of Microdochium spp. under changing climatic conditions, particularly during the early growth stages of winter wheat. Full article

Turf grasses play a crucial role in enhancing the beauty and usability of landscapes, gardens, parks, and sports facilities due to their functional and aesthetic properties. However, various unfavourable conditions, such as plant disorders and environmental pressures, can compromise their amenity value. Ongoing research aims to identify natural remedies that improve the quality and resilience of these grasses. A study was conducted at the Experimental Station of the Agricultural University of Krakow (50°07′ N, 20°05′ E) to evaluate the practical value of the turf produced by seeding of the ‘Super Lawn’ grass mixture. The experiment involved applying a spray containing oligogalacturonides at two doses: 1.0 and 2.0 dm³∙ha⁻¹, along with a commercial fungicide. The traits were analysed using a 9-point scale. Plants in variant III (treated with the higher dose of oligogalacturonides) and variant IV (treated with the commercial fungicide) exhibited the highest aesthetic and functional values. The application of oligogalacturonides and a commercial fungicide resulted in a decrease in plant diseases. The treatment area showed a reduction in pink snow mould (Microdochium nivale) and leaf spot incidence compared to the control area. Variant II showed enhanced outcomes with the application of 1.0 dm³∙ha⁻¹ of the preparation. In this area, the plant canopy had greater coverage, and the plants demonstrated increased resistance to pink snow mould and leaf spot compared to the plants in the control area. The use of commercial fungicide was found to be more effective than applying oligogalacturonides. Additionally, the plants that were protected with the fungicide displayed the highest values for the analysed parameters. Full article

The study investigates through hygrothermal modelling the effect of different boundary conditions and varying measured vapour diffusion resistivity values on the hygrothermal performance of five pliable membranes. Previously, this research quantified the variable water vapour diffusion resistivity properties of five different pliable building membranes. The membranes were assessed under varying humidity conditions using the gravimetric wet and dry cup test method. The varying humidity conditions better represent the boundary conditions experienced by materials in the building envelope. The pliable membranes include two permeable, two impermeable, and one variable products, which are commonly used to provide air and vapour control layers in the construction of framed external wall systems. This article focusses on the transient hygrothermal modelling of each of these membranes as a component of a typical timber-framed, clay brick veneer external wall system. The simulations were completed for three different climate types, namely, hot and humid, temperate, and cool-temperate with snow, and with a northern and western orientation. The results from hygrothermal and bio-hygrothermal simulations highlighted different responses subject to climate type and orientation. These results show that there are significant differences in simulated moisture and mould growth risk between the results of pliable membranes with single vapour resistance factor value and pliable membranes with multipoint vapour resistance factor values. Full article

Innovative materials for substituting metals are required to reduce the mass of moving components. This decreases the CO₂ emissions of overall systems. A thermoset sandwich for high mechanical properties and thermal insulation is presented in this paper. It has an innovative 3D continuous reinforced core, which allows the optimisation of the substance exploitation by wide-ranging possibilities of fibre orientation. This was demonstrated with three sandwich variants. The reference had no core reinforcement and the other two were reinforced with different spacer fabrics. The process chain for the manufacturing consists of Structural Reaction Injection Moulding (SRIM) and Vacuum Assisted Resin Transfer Moulding (VARTM). Significant increases in absolute as well as specific characteristic values were demonstrated by the reinforcement in a compression and bending test. It was also shown that quasi-static characteristic values under fatigue loading are maintained to a greater extent with the core reinforcement. The sandwich material was applied as a floor assembly for a snow groomer. The design was tailor-made for the mechanical, thermal and acoustic requirements. This proved the transferability of the process chain for manufacturing samples to the production of large-volume components with complex geometry. Full article

Although climate change is well recognised as an important issue in Japan, there has been little interest from scientists or the public on the potential threat it poses to heritage. The present study maps the impact of emerging pressures on museums and historic buildings in the Tokyo Area. We examine a context to the threat in terms of fluctuating levels of visitors as a response to environmental issues, from SARS and COVID-19, through to earthquakes. GIS mapping allows a range of natural and human-induced hazards to be expressed as the spatial spread of risk. Temperature is increasing and Tokyo has a heat island which makes the city hotter than its surroundings. This adds to the effects of climate change. Temperature increases and a decline in relative humidity alter the potential for mould growth and change insect life cycles. The region is vulnerable to sea level rise, but flooding is also a likely outcome of increasingly intense falls of rain, especially during typhoons. Reclamation has raised the risk of liquefaction during earthquakes that are relatively frequent in Japan. Earthquakes cause structural damage and fires after the rupture of gas pipelines and collapse of electricity pylons. Fires from lightning strikes might also increase in a future Tokyo. These are especially relevant, as many Japanese heritage sites use wood for building materials. In parallel, more natural landscapes of the region are also affected by a changing climate. The shifting seasons already mean the earlier arrival of the cherry blossom and a later arrival of autumn colours and a lack of winter snow. The mapping exercise should highlight the spatial distribution of risk and the way it is likely to change, so it can contribute to longer term heritage management plans. Full article