Search results for "HVA"
showing 10 items of 78 documents
Optimization of hybrid – ground coupled and air source – heat pump systems in combination with thermal storage
2010
Ground coupled heat pumps are attractive solutions for cooling and heating commercial buildings due to their high efficiency and their reduced environmental impact. Two possible ideas to improve the efficiency of these systems are decoupling energy generation from energy distribution and combining different HVAC systems. Based on these two ideas, we present several HVAC configurations which combine the following equipments: a ground coupled heat pump, an air to water heat pump and a thermal storage device. These HVAC configurations are linked to an office building in a cooling dominated area in order to evaluate in these conditions the total electrical consumption of each configuration to o…
Sosiaalinen pääoma ja yksilötason tulokehitys Suomessa
2018
Tässä tutkimuksessa tarkastelemme yksilön sosiaalisista verkostoista muodostuvan sosiaalisen pääoman yhteyttä yksilötason tulokehitykseen. Analyysimme perustuvat vuoden 1986 elinolotutkimukseen osallistuneisiin 20–44 vuotiaisiin työllisiin ja rekisteritietoihin heidän palkkatuloistaan vuosilta 1987–1997. Tutkimuksessa erottelemme toisistaan sitovan ja silloittavan sosiaalisen pääoman muodot. Sitovan sosiaalisen pääoman mittarimme perustuu yksilön mahdollisuuteen saada apua verkostoistaan erilaisissa arkielämän tilanteissa. Silloittavaa sosiaalista pääomaa mittasimme yksilöiden yhdistysjäsenyyksien monipuolisuuden kautta. Analyysit suoritettiin paloittain jatkuvalla linea…
The effect of patchy distribution ofStipa tenacissimaL. on runoff and erosion
1997
In south-east Spain, a semi-arid area,Stipa tenacissima(alphagrass) covers large natural and semi-natural areas with a mosaic of tussocks and bare zones. However, little knowledge exists about the influence of these patterns on runoff and erosion. In order to understand the hydrological and erosional behaviour of the vegetated (herbs andalphagrass) and bare zones, rainfall simulation experiments were carried out at three sites in south-east Spain. The experiments showed that surface runoff and erosion is negligible in the tussock and quite high in the bare areas. High infiltration rates and deep wetting fronts were measured in the vegetated patches, and lower infiltration rates and shallowe…
A Systematic Review of the Hydrological, Environmental and Durability Performance of Permeable Pavement Systems
2021
Due to urbanization, large portions of vegetated territory have been replaced by waterproof surfaces. The consequences are greater outflows, lower infiltration, and lower evapotranspiration. Pavement systems made with permeable surfaces allow the infiltration of water, ensuring reduction of runoff volume. In this paper, the methods of analysis of the hydrological and environmental performance of the pavement systems are reviewed in the context of urban drainage and regarding their durability. The purpose is to present an overview of the studies published during the last decade in the field. The Pubmed and Web Science Core Collection electronic databases were used to conduct the scientific l…
Henkilöiden väliset heikot ja vahvat siteet hajautetussa työssä : yhteistyötä tukevat teknologiat
2015
Lähivuosien teknologinen kehitys ja muutokset globaalissa taloudessa ovat muuttaneet monien alojen toimintaympäristöä merkittävästi. Ihmiset ovat yhteydessä toisiinsa informaatioteknologian avulla niin työssä kuin vapaa-ajallakin. Erityisesti tietotyössä on kasvava tarve hajautetulle työlle ja joustaville työjärjestelyille. Oikean yhteistyöteknologian valinta on yrityksille merkittävä liiketoimintaan vaikuttava tekijä. Tutkielman aiheena on tutkia henkilöiden välisiä siteitä (heikkoja ja vahvoja) ja sitä, kuinka niitä voidaan luoda tai ylläpitää yrityksessä tai organisaatiossa sosiaalisten ohjelmistojen avulla. Recent technological advances and changes in the global economy has had a major …
The contrasted response of ash to wetting
2013
Abstract After a wildfire the soil is covered by ash. Ash properties depend on vegetation type, amount of fuel and fire intensity. The ash layer controls the post-fire soil hydrologic response, but little is known about the effect of ash thickness and ash type on infiltration, which is relevant for post-fire runoff and soil losses and for ecosystems rehabilitation and restoration. This paper analyses the role of i) ash type (black or white), ii) thickness (5, 15 and 30 mm-thick) and iii) temporal variation (0, 15 and 40 days) under three simulated rain events (55 mm for 1 h) on soil surface hydrology. The rainfall was simulated on 0.25 m2 plots, and time to ponding, runoff and runoff discha…
Hydrological and hydraulic behaviour of a surface flow constructed wetland treating agricultural drainage water in northern Italy.
2020
Abstract A surface flow constructed wetland (SFCW) treating agricultural drainage water was investigated with the aim to detect modifications in hydrological and hydraulic characteristics after more than a decade of operation. Ponded infiltration tests were conducted to estimate the saturated hydraulic conductivity, Ks, of the surface soil layer at the point scale. At the global scale, infiltration rate, i, was computed from the water balance to detect leakages from the pervious wetland surface. Tracer tests were conducted to analyse the existence of preferential flow inside the system and to estimate its hydraulic retention time (HRT). Clogging phenomena occurred given a mean Ks value of 3…
Like barn leker mest, men er det best? : Integrering av enslige mindreårige gjennom fritidsaktiviteter
2016
Master thesis development management - University of Agder 2016
L’influenza dei sistemi per il condizionamento dell’aria sul consumo di energia elettrica del settore residenziale: un modello neurale
2008
Short-term prediction of household electricity consumption: assessing weather sensitivity in a Mediterranean area
2008
Abstract Urban microclimatic variations, along with a rapid reduction of unit cost of air-conditioning (AC) equipments, can be addressed as some of the main causes of the raising residential energy demand in the more developed countries. This paper presents a forecasting model based on an Elman artificial neural network (ANN) for the short-time prediction of the household electricity consumption related to a suburban area. Due to the lack of information about the real penetration of electric appliances in the investigated area and their utilization profiles it was not possible to implement a statistical model to define the weather and climate sensitivities of appliance energy consumption. F…