Search results for " Emissions"
showing 10 items of 260 documents
Insights into the effect of soil pH on N(2)O and N(2) emissions and denitrifier community size and activity.
2010
ABSTRACT The objective of this study was to investigate how changes in soil pH affect the N 2 O and N 2 emissions, denitrification activity, and size of a denitrifier community. We established a field experiment, situated in a grassland area, which consisted of three treatments which were repeatedly amended with a KOH solution (alkaline soil), an H 2 SO 4 solution (acidic soil), or water (natural pH soil) over 10 months. At the site, we determined field N 2 O and N 2 emissions using the 15 N gas flux method and collected soil samples for the measurement of potential denitrification activity and quantification of the size of the denitrifying community by quantitative PCR of the narG , napA ,…
Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states
2017
Abstract CaZrO3 (CZO) powders obtained by the polymeric precursor method at 400 °C, and then, the samples were annealed at different temperatures (400, 600, 800, and 1000 °C) and characterized by X-ray diffraction, Raman and ultraviolet–visible spectroscopic methods, along with photoluminescence (PL) emissions. First principle calculations based on the density functional theory (DFT), using a periodic cell models, provide a theoretical framework for understanding the PL spectra based on the localization and characterization of the ground and electronic excited states. Fundamental (singlet, s ) and excited (singlet, s* , and triplet, t* ) electronic states were localized and characterized us…
Impacts of roundabouts in suburban areas on congestion-specific vehicle speed profiles, pollutant and noise emissions: an empirical analysis
2019
Abstract Increasing concern about global warming and air quality has meant an increasing use of energetic and environmental indicators in roundabout design. This research compares different suburban roundabouts in terms of traffic performance, pollutant and noise emissions through an integrated empirical assessment. Field measurements were carried out with a light duty vehicle in single-lane (SL), compact two-lane (CTL) and multi-lane (ML) roundabouts using Portable Emission Measurements Systems, On-Board Diagnostic scan tool and Sound Level Meter, to measure real-world exhaust emissions, engine activity and acoustic data, respectively. Afterwards, predictive discrete choice models that cor…
Widening the applicability of AnMBR for urban wastewater treatment through PDMS membranes for dissolved methane capture: Effect of temperature and hy…
2021
[EN] AnMBR technology is a promising alternative to achieve future energy-efficiency and environmental-friendly urban wastewater (UWW) treatment. However, the large amount of dissolved methane lost in the effluent represents a potential high environmental impact that hinder the feasibility of this technology for full-scale applications. The use of degassing membranes (DM) to capture the dissolved methane from AnMBR effluents can be considered as an interesting alternative to solve this problem although further research is required to assess the suitability of this emerging technology. The aim of this study was to assess the effect of operating temperature and hydrodynamics on the capture of…
Environmental effects and potential impact on human health caused by the recent Nyiragongo eruption (Democratic Republic of Congo)
2022
Volcanic activity emits large amounts of gases and particles to the atmosphere subsequently spreading contaminants to rain, surface waters and soils, negatively impacting on the environment and the human health. The recent eruption of Nyiragongo occurred on 22nd of May, injected large quantities of ash affecting the environment of the Virunga area, and more than 2 million people living between 18-25 km far from the main crater of Nyiragongo. Several studies demonstrated that drinking waters and plants may contain high contents of natural pollutants, and when ingested they become harmful to human health causing acute or chronic diseases. In this study, we investigated the impact of the recen…
The Spanish Turn against Renewable Energy Development
2018
[EN] In this study, we focus on the case of Spanish energy policy and its implications for sustainable energy development. In recent years, Spanish legislation has changed dramatically in its approach to sustainable energy sources. This change is despite EU and international efforts to increase energy efficiency, and to accelerate the transition to renewable energy sources (RES) in order to reduce greenhouse gas emissions. Based on the socio-technical transitions literature, this paper assesses the role of the new legislation in this altered scenario, and analyzes the evolution of energy production in Spain in the EU context. The results are triangulated with two expert assessments. We find…
Eiropas Savienības CO2 emisijas kvotu tirdzniecības sistēma un Latvijas tautsaimniecības ilgtspējīga attīstība
2013
ANOTĀCIJA Promocijas darba mērķis ir, balstoties uz datiem par Eiropas Savienības Emisijas kvotu tirdzniecības sistēmas (ES ETS) darbību Latvijā un ES ETS integrētību Latvijas tautsaimniecības politikā, mikro un makro līmenī izpētīt ES ETS līdzšinējo ietekmi uz Latvijas tautsaimniecības ilgtspējīgu attīstību. Pētījuma ietvaros autore izstrādājusi modeli lēmuma pieņemšanai par tiešo dalību atļauju tirdzniecībā, formulējusi stratēģijas tiešajai dalībai atļauju tirdzniecībā, izvērtējusi ES ETS integrētību Latvijas tautsaimniecības ilgtspējīgas attīstības politikā, novērtējusi ES ETS ietekmi uz Latvijas ES ETS dalībniekiem, izanalizējusi Latvijas ES ETS dalībnieku zināšanas un izpratni par ES E…
Energy management strategy to reduce pollutant emissions during the catalyst light-off of parallel hybrid vehicles
2020
Abstract The transportation sector is a major contributor to both air pollution and greenhouse gas emissions. Hybrid electric vehicles can reduce fuel consumption and CO2 emissions by optimizing the energy management of the powertrain. The purpose of this study is to examine the trade-off between regulated pollutant emissions and hybrid powertrain efficiency. The thermal dynamics of the three-way catalyst are taken into account in order to optimize the light-off. Experimental campaigns are conducted on a spark-ignition engine to introduce simplified models for emissions, exhaust gas temperature, catalyst heat transfers and efficiency. These models are used to determine the optimal distribut…