Search results for " Monitoring"
showing 10 items of 3129 documents
Nucleation particles in diesel exhaust: composition inferred from in situ mass spectrometric analysis.
2005
Mass spectrometric measurements of size and composition of diesel exhaust particles have been performed under various conditions: chassis dynamometer tests, field measurements near a German motorway, and individual car chasing. Nucleation particles consisting of volatile sulfate and organic material could be detected both at the chassis dynamometer test facility and during individual car chasing. We found evidence that if nucleation occurs, sulfuric acid/water is the nucleating agent. Low-volatile organics species condense only on the preexisting sulfuric acid/water clusters. Nucleation was found to depend strongly on various parameters such as exhaust dilution conditions, fuel sulfur conte…
Energy efficiency in Spanish wastewater treatment plants: a non-radial DEA approach.
2011
Wastewater treatment plants (WWTPs) are energy-intensive facilities. Thus, reducing their carbon footprint is particularly important, both economically and environmentally. Knowing the real operating energy efficiency of WWTPs is the starting point for any energy-saving initiative. In this article, we applied a non-radial Data Envelopment Analysis (DEA) methodology to calculate energy efficiency indices for sampling of WWTPs located in Spain. In a second stage analysis, we examined the operating variables contributing to differences in energy efficiency among plants. It is verified that energy efficiencies of the analyzed WWTPs were quite low, with only 10% of them being efficient. We found…
Is Active Moss Biomonitoring Comparable to Air Filter Standard Sampling?
2022
Recently, significant attention has been paid to air quality awareness and its impact on human health, especially in urban agglomerations. Many types of dust samplers for air quality monitoring are used by governmental environmental monitoring agencies. However, these techniques are associated with high costs; as a consequence, biological methods such as active moss biomonitoring are being developed. The main disadvantages of such techniques are the lack of standardization of the preparation procedures and the lack of reliable comparisons of results with data from instrumental analyses. Our study aimed to compare the results obtained from active biomonitoring with the use of three moss spec…
Possible markers of traffic-related emissions
2007
Looking for robust indicators of motor vehicle emissions it has been found that brake wear and linings are significant contributors of Cu, Mo and Sb to air particulate matter. These trace elements, whose mutual ratios in airborne particulate matter resulted quite different from those in crustal material, appear to be available fingerprinting tools to identify the contribution of on-road vehicles to traffic-derived particulate matter. In this study, the results of analytical determinations of Cu, Mo and Sb on PM(10), PM(2.5), vegetation and brake dust samples, together with gas (CO, NOx) concentrations, are discussed. Highly significant correlations among Cu, Sb and Mo were observed in parti…
Environmental applications (air)
2020
Abstract The use of solid sorbent-based devices for the monitoring of contaminants in the air is a widespread trend due to its versatility, physicochemical stability, and high enrichment factor. Active and passive sampling strategies have been developed for air monitoring using different materials, such as carbon-based organic polymers and inorganic sorbents. It has been updated in the literature regarding the most recent applications of the use of solid sorbent-based samplers for the monitoring of air in different sites such as rural, urban, industrialized, and indoor areas, including workplace environments for the evaluation of occupational exposure risks.
Case study: inorganic pollutants associated with particulate matter from an area near a petrochemical plant.
2004
The area of Gela (Sicily, Italy) contains one of the largest petroleum refineries in Europe and also has several oil fields both on land and offshore. This paper discusses how the oil refinery and traffic-related air pollution affect the chemical composition of airborne particulate matter over the town of Gela, using pine needles and urban road dust as the means of survey. Forty-one samples of pine needles from Pinus halepensis (Mill.) and two composite samples of roadway dust, each subdivided into six size fractions, were analyzed for major and trace elements. Information on the natural or anthropogenic origin of the observed heavy metals was deduced from factor analysis and element distri…
Aspen Plus process-simulation model: Producing biogas from VOC emissions in an anaerobic bioscrubber
2018
A process-simulation model for a novel process consisted of an anaerobic bioscrubber was developed in Aspen Plus®. A novel approach was performed to implement the anaerobic reactor in the simulation, enabling it to be connected to the scrubber. The model was calibrated and validated using data from an industrial prototype that converted air emissions polluted with volatile organic compounds with an average daily concentration of 1129 mgC Nm−3 into bioenergy for more than one year. The scrubber, which showed a removal efficiency within 83-93%, was successfully predicted with an average absolute relative error of 5.2 ± 0.08% using an average height-to-theoretical-plate value of 1.05 ± 0.08 m …
Researches on the Alternative Fuels Which Can Be Used to Motors
2010
The alternative fuels are substances or materials used as fuel, other than the old conventional fuels (oil, natural gases and coals). 
 The paper analyses the most important alternative fuels, such as: bio-diesel, alcohols and hydrogen, presenting at each category the main important characteristics, the advantages and disadvantages presented by them. 
 The methyl-ester which is known as bio-diesel can be used in all motors with ignition by compression, alone or mixed in any proportion with oil, with minor modifications at the injection system. Bio-diesel fuel assures the same motor power as oil does, having even a bigger cetanic number than the usual oil. After tests, it was obser…
International survey of antibiotic dosing and monitoring in adult intensive care units
2023
Background: In recent years, numerous dosing studies have been conducted to optimize therapeutic antibiotic exposures in patients with serious infections. These studies have led to the inclusion of dose optimization recommendations in international clinical practice guidelines. The last international survey describing dosing, administration and monitoring of commonly prescribed antibiotics for critically ill patients was published in 2015 (ADMIN-ICU 2015). This study aimed to describe the evolution of practice since this time. Methods: A cross-sectional international survey distributed through professional societies and networks was used to obtain information on practices used in the dosing…
A procedure to calculate the I–V characteristics of thin-film photovoltaic modules using an explicit rational form
2015
Abstract Accurate models of the electrical behaviour of photovoltaic modules are effective tools for system design. One or two diode equivalent circuits have been widely used even though some mathematical difficulties were found dealing with implicit equations. In this paper, a new model based on a simple rational function, which does not contain any implicit exponential form, is presented. The model was conceived in order to be used with thin-film photovoltaic modules, whose current–voltage curves are characterised by very smooth shapes. The parameters of the model are evaluated by means of the derivatives of the issued characteristics in the short circuit and open circuit points at standa…