0000000000074352
AUTHOR
Inga Apine
Establishing material hygrothermal characteristics via long-term monitoring and best-fit numerical models
Numerical models of heat and moisture transfer for performance forecast of lightweight insulating assemblies require many inputs. These include exterior climate data (i.e. temperature, relative humidity, solar radiation), interior climate data or standard models, transfer coefficients, correct initial conditions, etc. Most importantly, one needs reliable material models. A material model includes porosity, density, heat capacity, but also non-constant properties, such as thermal conductivity, vapor/liquid water diffusivity, sorption curves. These are, in general, difficult to determine, and material database entries often are incomplete, or simply non-existent. However, if one performs long…
Vasarzaļo rododendru spraudeņu pavairošanas potenciāls atkarībā no mātes augu un spraudeņu apstrādes
Darba mērķis bija noskaidrot vasarzaļo rododendru spraudeņu pavairošanas potenciālu atkarībā no mātes augu priekšapstrādes (etiolācija, steidzināšana) un spraudeņu apstrādes ar auksīnu – indol-3-sviestskābi (ISS). Mātes augu etiolācija kopā ar ISS veicināja straujāku rizoģenēzi, bet neietekmēja apsakņoto spraudeņu skaitu. Etiolācija uzlaboja pārziemošanu grūtāk apsakņojamiem spraudeņiem. Mātes augu steidzināšana kopā ar ISS uzlaboja spraudeņu rizoģenēzi grūtāk apsakņojamiem genotipiem, veicināja jauno dzinumu attīstību, uzlabojot spraudeņu pārziemošanu. Nodrošinot apsakņotajiem spraudeņiem nepārtrauktu veģetācijas periodu, var būtiski palielināt pārziemojušo spraudeņu skaitu. Cietes koncent…
Powdery mildew on Rhododendron caused by Erysiphe azaleae in Latvia.
In 2002 a fungus causing powdery mildew on Rhododendron in Latvia was discovered and identified as Erysiphe azaleae. The powdery mildew has since then been observed on leaves and seed pods of deciduous azaleas as well as evergreen rhododendrons, although the disease is more common on taxa of deciduous azaleas. Development of mature chasmothecia has been noticed at every location where the disease was detected. The distribution area of E. azaleae is expanding gradually from the south-west and central regions to the north and east parts of Latvia. It has been suggested, that climate change and large-scale plant import favour this process. To our knowledge, Latvia is so far the farthest north-…
Comparative Assessment of Mould Growth Risk in Lightweight Insulating Assemblies Via Analysis of Hygrothermal Data and In Situ Evaluation
In order to assess the sustainability of buildings with different types of insulating assemblies in the Latvian climate, a long-term test building monitoring experiment has been underway since 2013. There are a total of five test buildings on site with roughly six years’ worth of accumulated temperature and humidity readings in the key parts of assemblies. This study is meant to quantify the mould presence in building walls, floor and ceiling by performing laboratory tests, assessing the number of colony-forming units, and comparing the results with mould risk predictions due to the isopleth model developed by Sedlbauer, using both the hygrothermal data derived from the sensors within build…
Melampsora allii-fragilis f. sp. galanthi-fragilis reported for first time to cause rust on Galanthus plicatus in Latvia
In Europe, Melampsora allii-fragilis f. sp. galanthi-fragilis (syn. Melampsora galanthi-fragilis) has been reported on leaves of snowdrop (Galanthus nivalis) in Romania (Savulescu, 1953; Bagyanarayana, 2005) and on Galanthus plicatus in Ukraine (Gutsevich, 1952). The GBIF Database has additional records of this fungus on G. nivalis from Austria, Czech Republic and France but the USDA SMML Specimens Database has also records from Hungary and Poland. According to this database, the established distribution area of M. allii-fragilis f. sp. galanthi-fragilis is ‘Central Europe’. Melampsora allii-fragilis f. sp. galanthi-fragilis belongs to the heteroecious rust fungi that require two hosts to c…
Numerical models for long-term performance assessment of lightweight insulating assemblies
Abstract This paper presents the results of numerical modelling of hygrothermal processes in test buildings situated in the Botanical garden of the University of Latvia. Long-term performance of wall, floor and ceiling insulating assemblies for five different buildings was simulated using WUFI Pro 6.3. On the experimental side, measurements of temperature and relative humidity at key points of assembles have been accumulated over a period of roughly six years and material samples were taken from building envelope materials for biological analysis. We found that our models rather successfully reproduce the experientially observed temperature and relative humidity dynamics. In the process, we…
Plant diseases a herald of environmental changes
Environmental changes can alter morphology and physiology of plants, and geographic distribution of both wild and cultural species. All these modifications reflect in plant-associated microflora and development of plant pathogens as well. Climate warming causes a pole-ward shift not only different plants but also their pathogens. Poster in 4th International Conference of Botanic Gardens from the Baltic Sea Region "Botanic gardens network for the development of the Baltic Sea Region", 29 September - 2 October, 2011, Gdansk, Poland