Search results for "DFI"
showing 10 items of 128 documents
Trace compounds of biogas from different biogas production plants
2007
Biogas composition and variation in three different biogas production plants were studied to provide information pertaining to its potential use as biofuel. Methane, carbon dioxide, oxygen, nitrogen, volatile organic compounds (VOCs) and sulphur compounds were measured in samples of biogases from a landfill, sewage treatment plant sludge digester and farm biogas plant. Methane content ranged from 48% to 65%, carbon dioxide from 36% to 41% and nitrogen from <1% to 17%. Oxygen content in all three gases was <1%. The highest methane content occurred in the gas from the sewage digester while the lowest methane and highest nitrogen contents were found in the landfill gas during winter. The amoun…
The Landfilling of Municipal Solid Waste and the Sustainability of the Related Transportation Activities
2022
The management of municipal solid waste is a crucial issue to address as we move toward the decarbonization of urban contexts. Not by chance, this sector plays a relevant role in the Covenant of Mayors program, whereby municipalities are called to design their own Sustainable Energy Action Plans (SECAPs). However, despite new regulations strongly pushing the recycling and reuse of materials contained in municipal waste, many cities still use large landfills. As part of the overall environmental pressure exerted by these urban systems, the transport of waste from collection points to landfills or treatment facilities must be considered in order to correctly assess the full environmental burd…
The analysis of methods for measurement of methane oxidation in landfills
2003
Landfills and dumps are important sources of atmospheric methane. There is no generally accepted estimate of the influence of methane oxidation on landfill methane emissions. The present work aimed to analyse different methods for the investigation of methane emission and oxidation in methane-producing environments (wetlands, landfills, sludge checks), and to develop the precise procedure for the landfills. The combination of geochemical and microbiological methods to estimate and monitor the oxidation and emission of methane in landfills during different seasons is proposed. It includes the measurements, both on the surface and at different depths (up to 1 m) of landfill ground of the foll…
Biogas Pollution and Mineral Deposits Formed on the Elements of Landfill Gas Engines
2022
Municipal landfills generate a significant amount of high-energy biogas, which can be used as a renewable gaseous fuel. However, it is necessary to improve the quality of this biogas due to the presence of various chemical compounds. The most common pollutants in landfill biogas include volatile compounds of silicon, sulphur, phosphorus and chlorine. The aforementioned elements, as well as other metals, were found both in the deposits and in the engine oil. The paper presents detailed characteristics of the solid residues formed in selected parts of gas engines powered by landfill biogas. Its elemental composition and morphology were investigated in order to determine the structure and infl…
Biogas composition and upgrading to biomethane
2009
Saija Rasin tutkimus osoittaa, että jätteistä tai energiakasveista tuotettua biokaasua voidaan hyödyntää sähkön ja lämmön tuotantoon. Biokaasua voidaan käyttää jalostettuna myös korkealaatuista polttoainetta vaativissa kohteissa, kuten ajoneuvoissa ja polttokennoissa. Fossiilisten polttoaineiden korvaaminen uusiutuvilla polttoaineilla, esimerkiksi biokaasulla, vähentää merkittävästi kasvihuone- ja muita haitallisia päästöjä. Biokaasun pääkomponentit ovat metaani ja hiilidioksidi, ja lisäksi se voi sisältää pieniä pitoisuuksia energiakäyttöä haittaavia yhdisteitä, joiden määrä ja laatu vaihtelevat. Nämä yhdisteet voivat esimerkiksi estää koko teknologian käytön tai lyhentää laitteistojen huo…
Motion detection in goldfish investigated with the optomotor response is “color blind”
1996
AbstractThe action spectrum of the optomotor response in goldfish was measured to investigate which of the four cone types involved in color vision contributes to motion detection. In the dark-adapted state, the action spectrum showed a single maximum in the range of 500–520 nm, and resembled the rod spectral sensitivity function. Surprisingly, the action spectrum measured in the light-adapted state also revealed a single maximum only, located in the long wavelength range between 620 and 660 nm. A comparison with spectral sensitivity functions of the four cone types suggests that motion detection is dominated by the L-cone type. Using a two colored, “red-green” cylinder illuminated with two…
Temporal resolution and temporal transfer properties: gabaergic and cholinergic mechanisms.
2007
Temporal resolution is a basic property of the visual system and critically depends upon retinal temporal coding properties which are also of importance for directional coding. Whether the temporal coding properties for directional coding derive form inherent properties or critically depend upon the temporal coding mechanisms is unclear. Here, the influence of acetylcholine and GABA upon photopic temporal coding was investigated in goldfish, using flicker stimuli, in a behavioral and an electrophysiological (ERG) approach. The goldfish temporal resolution ability decreased from more than 90% correct choices at 20 Hz flicker frequency to about 65% at 45 Hz flicker frequency with a flicker fu…
Production and extraction of astaxanthin from Phaffia rhodozyma and its biological effect on alcohol-induced renal hypoxia in Carassius auratus
2015
The effect of astaxanthin (3,3â²-dihydroxy-s-carotene-4,4â²-dione) on alcohol-induced morphological changes in Carassius auratus, as an experimental model, was determined. The yeast Phaffia rhodozyma was used as a source of astaxanthin. The animals were divided into three groups for 30 days: one group was treated with ethanol at a dose of 1.5% mixed in water, the second one with EtOH 1.5% and food enriched with astaxanthin from P. rhodozyma, and the third was a control group. After a sufficient experimental period, the samples were processed using light microscopy and evaluated by histomorphological and histochemical staining, and the data were supported by immunohistochemical analysis, u…
Mākslas pasaules alūzijas Donnas Tartas romānā “The Goldfinch”
2018
Donnas Tartas romāns „The Goldfinch” kopš tā publicēšanas radījis sajūsmas vilni literatūras kritiķos un lasītājos visā pasaulē, piedzīvojot tulkojumu trīsdesmit valodās. Tomēr, izvērtējot iespējamo tulkojumu latviešu valodā, romānā attēlotā mākslas pasaule un alūzijas uz to varētu radīt ievērojamus sarežģījumus romāna tulkotājam. Tādēļ šajā darbā tiek pētītas īpašvārdu alūzijas uz mākslas pasauli, padziļināti apskatot tieši mākslas un literatūras alūzijas, un tiek izdarīti secinājumi par to iespējamo atveidi tulkojumā latviešu valodā, balstoties uz tulkošanas teorijā piedāvātajām stratēģijām un domāšanas modeļiem, ko piedāvā tādi autori kā Ritva Lepihalme, Ričards Tomass, kā arī Stīvens Ha…
Compound climate extreme events threaten migratory birds’ conservation in western U.S.
2022
In a warming world, more intense and frequent compound climate extreme events pose serious challenges to biodiversity and conservation on Earth as one of the 2030 United Nations’ sustainable development goals (SDGs): “Life On Land” (SDG 15). In summer 2020, concurrent swelling wildfires and a sudden cold snap in the western U.S. killed a massive number of migratory birds. In August 2020, the hot and humid weather in response to the wildfire radiation and the oceanic evaporation could result in killing heat stress for migratory birds along the coastal shoreline, particularly in California. The heat and smoke of wildfires forced the migratory birds to abandon such feeding grounds towards inla…