Search results for "Thermal"
showing 10 items of 3576 documents
Establishing material hygrothermal characteristics via long-term monitoring and best-fit numerical models
2020
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…
Model research on the influence of green roofs on environmental parameters in urban agglomerations
2018
The intensive development of urban agglomerations in Poland and other European countries has rendered the growth of biologically active areas more important with respect the quality of the urban environment. Taking the rapidly rising prices of plots in city centers into consideration, it is worth noting the vast surfaces of building roofs that can be used as biologically active areas. The term green roof is to be understood as an open, overgrown surface on a multilayer roof of a building. Green roofs can only be made on a planar surface with an inclination of 2% to 30%. In accordance with the type of usage, construction factors and maintenance requirements, green roofs are typically defined…
Examination of coagulant additives on qualitative composition of selected thermal waters
2017
On the territory of Poland occur rich deposits of thermal waters. Although the utilisation of these waters is continuously extending, Poland is not exploiting their full geothermal potential due to high investment costs. Thermal waters industry in Poland to date indicates operations within mainly balneology as well as recreation objectives. Higher temperature values of these waters foster a washout in the surrounding rocks resulting in a high concentration of diluted substances which must be often removed. The following study investigates thermal waters from three intakes for which coagulation processes were conducted. Research clearly shows that coagulant additives not impact on the qualit…
Methodology for Calculating the Potential Maritime Wind Park Area by Taking into Account the Needs of Shipping Sector
2018
Renewable energy sources (wind energy, solar energy, hydroelectricity, ocean energy, geothermal energy, biomass and biofuels) are alternatives to fossil fuel that help to reduce greenhouse gas emissions, diversify energy supplies and reduce dependency on markets of unsustainable and volatile fossil fuels, particularly oil and gas. Wind energy is one of the renewable energy sources and is considered to be self-renewable as it is the result of the Sun’s activity. Using wind energy is a rapidly developing industry today, and more and more wind turbines are installed worldwide every year, land-based wind turbines being more widespread than offshore ones. In Latvia, spread of land-based wind par…
The possibilities of energy storage in bulk materials
2018
The increased demand for energy from renewable sources entails the development of storage systems. The purpose of these systems is to supply energy on demand during periods which may not be concurrent with the time of the most efficient production of this energy. Various systems are being developed for storing energy in various forms and over various lengths of time.This paper presents selected projects and the results of studies into thermal energy storage. The results of the present author's own research into the transport of thermal energy in granular beds are also presented. The curves of temperature distribution have been determined; they are essential for the design of the thermal sto…
Impact of climate change on the timing of strawberry phenological processes in the Baltic States
2016
Climate change has been shown to impact aspects of agriculture and phenology. This study aims to quantify changes in the timing of garden strawberry blooms and harvests in the Baltic States using Regional Climate Models (RCMs). First, parameters for a strawberry phenology model based on the growing degree day (GDD) methodology were determined. Growing degree days were calculated using a modified sine wave method that estimates the diurnal temperature cycle from the daily maximum and minimum temperature. Model parameters include the base temperature and the required cumulative GDD sum, estimated from phenological and meteorological observations in Latvia for the years 2010–2013 via iterative…
Growth of beryllium oxide nano-structures during thermal treatment of neutron irradiated beryllium
2015
Beryllium oxide nano-structures grown during high temperature oxidation of neutron irradiated beryllium has been investigated. Oxidation of non - irradiated and neutron irradiated beryllium was performed in differential thermal analyzer in an atmosphere of air and its mixture with helium at temperatures up to 1050°C. Structure of beryllium and its oxide was studied by the means of scanning electron microscopy. The growth of beryllium oxide nano-structures – “labyrinth type” layers and nano-rods on the inner surfaces of neutron irradiated beryllium were observed by means of Scanning Electron Microscopy. The size of the rods was 10-100 nm in diameter and up to few micrometers in length. There…
Influence of Biomass Combustion Products on Element Content and Thermal Stability of Latvian Sheep Breed Wool Filter Fibres
2020
Sheep wool is natural, easy obtainable, renewable and biodegradable material with a perspective application as a sorbent in filters for purification of industrial emissions from various environmental pollutants. The element content and thermal stability of Latvian dark-headed sheep wool filter fibres was analysed and described before and after exposure to biomass combustion products. Based on the obtained results, it is concluded that the sheep wool filter fibres can sorb various gaseous combustion products, such as carbon monoxide (CO), carbon dioxide (CO2) and nitrogen oxides (NOx), however, the sorption processes of these gases are irreversible. The obtained results of total reflection X…
Adaptations to thermal variation in two Mediterranean limpets - cardiac response and haemocyte lysosomal stability
2012
Patella rustica and Patella caerulea are two congeneric limpet species, both occurring along the rocky shores of the Mediterranean but on different tidal heights. P. rustica is dominant in the upper intertidal zone while P. caerulea is more abundant in the lower part of the same zone. Understanding variations in physiological adaptations to thermal stress is vital when investigating intertidal species' distribution. Hence, to investigate the relationship between their physiological thermal tolerance and intertidal zonation, laboratory experiments were designed to test the hypothesis that the lower zoned P. caerulea has reduced upper thermal limits when compared with higher zoned P. rustica,…
Biogas production from ensiled maize with and without hydrothermal pretreatment
2010
Energy crops are suitable substrates for anaerobic digestion. In the future their use will probably increase, and among other things optimum storage and pretreatment technologies should be developed. In this study eight maize silage varieties grown in Piikkiö, Southern Finland were used as substrates in anaerobic digestion. Also hydrothermal pretreatment was used to improve the biogas yield. Composition of the maize silage and the pretreated maize silage were analyzed and inhibitors were analyzed from the pretreated maize silage. The maize silages produce methane as much as fresh maizes in previous studies, when losses during the ensiling are taking into account and even 25-50 % more when l…