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Waste Heat Recovery (WHR) by means of an Organic Rankine Cycle is a technology often proposed to reduce the fuel consumption and CO2 emissions of heavy-duty vehicles. A Class 5 Heavy Lorry (tractor) with a WHR system was measured over various driving cycles on the chassis dyno and under realistic conditions on the road, performing each test-cycle with WHR enabled and disabled. The use of WHR lead to reductions in fuel consumption of 3.1% over the World Harmonized Vehicle Cycle, 2.5% over the Regional Delivery Cycle (RDC) and 1.9% over the on-road trips. The WHR system was able to produce more power output during the RDC on the chassis dyno compared to the on-road trips, as more exhaust energy was available during the RDC, resulting in a more considerable reduction of the fuel consumption. No statistically significant reduction of the pollutant emissions was observed. On-road trips were simulated with the Vehicle Energy Consumption calculation Tool, (VECTO), and the fuel consumption was predicted with an error of less than 1.5% for the individual trips and less than 0.5% when averaged over the different repetitions. These findings demonstrate the capability of VECTO to accurately simulate vehicles with Waste Heat Recovery under realistic conditions on the road.
Stijn Broekaert; Theodoros Grigoratos; Dimitrios Savvidis; Georgios Fontaras. Assessment of waste heat recovery for heavy-duty vehicles during on-road operation. Applied Thermal Engineering 2021, 191, 116891 .
AMA StyleStijn Broekaert, Theodoros Grigoratos, Dimitrios Savvidis, Georgios Fontaras. Assessment of waste heat recovery for heavy-duty vehicles during on-road operation. Applied Thermal Engineering. 2021; 191 ():116891.
Chicago/Turabian StyleStijn Broekaert; Theodoros Grigoratos; Dimitrios Savvidis; Georgios Fontaras. 2021. "Assessment of waste heat recovery for heavy-duty vehicles during on-road operation." Applied Thermal Engineering 191, no. : 116891.
A vehicle’s air drag coefficient (Cd) and rolling resistance coefficient (RRC) have a significant impact on its fuel consumption. Consequently, these properties are required as input for the certification of the vehicle’s fuel consumption and Carbon Dioxide emissions, regardless of whether the certification is done via simulation or chassis dyno testing. They can be determined through dedicated measurements, such as a drum test for the tire’s rolling resistance coefficient and constant speed test (EU) or coast down test (US) for the body’s air Cd. In this paper, a methodology that allows determining the vehicle’s Cd∙A (the product of Cd and frontal area of the vehicle) from on-road tests is presented. The possibility to measure these properties during an on-road test, without the need for a test track, enables third parties to verify the certified vehicle properties in order to preselect vehicle for further regulatory testing. On-road tests were performed with three heavy-duty vehicles, two lorries, and a coach, over different routes. Vehicles were instrumented with wheel torque sensors, wheel speed sensors, a GPS device, and a fuel flow sensor. Cd∙A of each vehicle is determined from the test data with the proposed methodology and validated against their certified value. The methodology presents satisfactory repeatability with the error ranging from −21 to 5% and averaging approximately −6.8%. A sensitivity analysis demonstrates the possibility of using the tire energy efficiency label instead of the measured RRC to determine the air drag coefficient. Finally, on-road tests were simulated in the Vehicle Energy Consumption Calculation Tool with the obtained parameters, and the average difference in fuel consumption was found to be 2%.
Dimitrios Komnos; Stijn Broekaert; Theodoros Grigoratos; Leonidas Ntziachristos; Georgios Fontaras. In Use Determination of Aerodynamic and Rolling Resistances of Heavy-Duty Vehicles. Sustainability 2021, 13, 974 .
AMA StyleDimitrios Komnos, Stijn Broekaert, Theodoros Grigoratos, Leonidas Ntziachristos, Georgios Fontaras. In Use Determination of Aerodynamic and Rolling Resistances of Heavy-Duty Vehicles. Sustainability. 2021; 13 (2):974.
Chicago/Turabian StyleDimitrios Komnos; Stijn Broekaert; Theodoros Grigoratos; Leonidas Ntziachristos; Georgios Fontaras. 2021. "In Use Determination of Aerodynamic and Rolling Resistances of Heavy-Duty Vehicles." Sustainability 13, no. 2: 974.
The relative contribution of brake emissions to traffic-induced ambient Particulate Matter (PM) concentrations has increased over the last decade. Nowadays, vehicles’ brakes are recognised as an important source of non-exhaust emissions. Up to now, no standardised method for measuring brake particle emissions exists. For that reason, the Particle Measurement Programme (PMP) group has been working on the development of a commonly accepted method for sampling and measuring brake particle emissions. The applied braking cycle is an integral part of the overall methodology. In this article, we present the results of an interlaboratory study exploring the capacity of existing dynamometer setups to accurately execute the novel Worldwide Harmonised Light-Duty Vehicles Test Procedure (WLTP)–brake cycle. The measurements took place at eight locations in Europe and the United States. Having several dynamometers available enabled the coordination and execution of the intended exercise, to determine the sources of variability and provide recommendations for the correct application of the WLTP–brake cycle on the dyno. A systematic testing schedule was applied, followed by a thorough statistical analysis of the essential parameters according to the ISO 5725 standards series. The application of different control programmes influenced the correct replication of the cycle. Speed control turned out to be more accurate and precise than deceleration control. A crucial output of this interlaboratory study was the quantification of standard deviations for repeatability (between repeats), sample effect (between tests), laboratory effect (between facilities), and total reproducibility. Three critical aspects of the statistical analysis were: (i) The use of methods for heterogeneous materials; (ii) robust algorithms to reduce the artificial increase in variability from values with significant deviation from the normal distribution; and (iii) the reliance on the graphical representation of results for ease of understanding. Even if the study of brake emissions remained out of the scope of the current exercise, useful conclusions are drawn from the analysis of the temperature profile of the WLTP–brake cycle. Urban braking events are generally correlated to lower disc temperature. Other parameters affecting the brake temperature profile include the correct application of soak times, the temperature measurement method, the proper conditioning of incoming cooling air and the adjustment of the cooling airspeed.
Theodoros Grigoratos; Carlos Agudelo; Jaroslaw Grochowicz; Sebastian Gramstat; Matt Robere; Guido Perricone; Agusti Sin; Andreas Paulus; Marco Zessinger; Alejandro Hortet; Simone Ansaloni; Ravi Vedula; Marcel Mathissen. Statistical Assessment and Temperature Study from the Interlaboratory Application of the WLTP–Brake Cycle. Atmosphere 2020, 11, 1309 .
AMA StyleTheodoros Grigoratos, Carlos Agudelo, Jaroslaw Grochowicz, Sebastian Gramstat, Matt Robere, Guido Perricone, Agusti Sin, Andreas Paulus, Marco Zessinger, Alejandro Hortet, Simone Ansaloni, Ravi Vedula, Marcel Mathissen. Statistical Assessment and Temperature Study from the Interlaboratory Application of the WLTP–Brake Cycle. Atmosphere. 2020; 11 (12):1309.
Chicago/Turabian StyleTheodoros Grigoratos; Carlos Agudelo; Jaroslaw Grochowicz; Sebastian Gramstat; Matt Robere; Guido Perricone; Agusti Sin; Andreas Paulus; Marco Zessinger; Alejandro Hortet; Simone Ansaloni; Ravi Vedula; Marcel Mathissen. 2020. "Statistical Assessment and Temperature Study from the Interlaboratory Application of the WLTP–Brake Cycle." Atmosphere 11, no. 12: 1309.
Brake wear emissions with a special focus on particle number (PN) concentrations were investigated during a chassis dynamometer measurement campaign. A recently developed, well-characterized, measurement approach was applied to measure brake particles in a semi-closed vehicle setup. Implementation of multiple particle measurement devices allowed for simultaneous measurement of volatile and solid particles. Estimated PN emission factors for volatile and solid particles differed by up to three orders of magnitude with an estimated average solid particle emission factor of 3∙109 # km−1 brake−1 over a representative on-road brake cycle. Unrealistic high brake temperatures may occur and need to be ruled out by comparison with on-road temperature measurements. PN emissions are strongly temperature dependent and this may lead to its overestimation. A high variability for PN emissions was found when volatile particles were not removed. Volatiles were observed under high temperature conditions only which are not representative of normal driving conditions. The coefficient of variation for PN emissions was 1.3 without catalytic stripper and 0.11 with catalytic stripper. Investigation of non-braking sections confirmed that particles may be generated at the brake even if no brakes are applied. These “off-brake-event” emissions contribute up to about 30% to the total brake PM10 emission.
Marcel Mathissen; Theodoros Grigoratos; Tero Lahde; Rainer Vogt. Brake Wear Particle Emissions of a Passenger Car Measured on a Chassis Dynamometer. Atmosphere 2019, 10, 556 .
AMA StyleMarcel Mathissen, Theodoros Grigoratos, Tero Lahde, Rainer Vogt. Brake Wear Particle Emissions of a Passenger Car Measured on a Chassis Dynamometer. Atmosphere. 2019; 10 (9):556.
Chicago/Turabian StyleMarcel Mathissen; Theodoros Grigoratos; Tero Lahde; Rainer Vogt. 2019. "Brake Wear Particle Emissions of a Passenger Car Measured on a Chassis Dynamometer." Atmosphere 10, no. 9: 556.
Vehicular evaporative emissions have been recognized as an important source of volatile organic compounds to the environment and are of high environmental concern since these compounds have been associated to the formation of surface ozone and secondary organic aerosols. Evaporative emissions occur during any vehicle operation. In Europe, a revised legislative test procedure has been recently introduced to better control evaporative emissions during parking. However, emissions related to normal driving conditions-the so-called running losses-have received less attention compared with the other categories. The current study aims at giving some insights to the prevailing temperature conditions in fuel tanks of typical European vehicles during normal driving operation. The effects of ambient air temperature, trip duration, vehicle speed, and fuel tank level on the temperature reached by the fuel inside the tank under different real-world operating conditions were studied. Tank temperature can exceed 40 °C depending on ambient and driving conditions. Ambient temperature was found to be the most important parameter affecting the tank temperature. Trip duration and driving pattern may also have an influence on the tank temperature particularly when long trips combined with high vehicle speed are examined. Additionally, the difference between tank and ambient temperature was examined during the individual trips and was found to vary between 1 and 10 °C depending on the testing conditions. The most important parameters affecting the delta temperature were found to be the trip duration and the maximum vehicle speed. Finally, the purging strategy of two of the test vehicles was monitored, and the parameters affecting the purging flow rate were investigated. No strong correlation between the canister flow rate with ambient temperature, vehicle speed, or fuel level was observed in either of the tested vehicles. Substantially different canister flow rate levels between the two vehicles point to different purging strategies.
Theodoros Grigoratos; Giorgio Martini; Massimo Carriero. An experimental study to investigate typical temperature conditions in fuel tanks of European vehicles. Environmental Science and Pollution Research 2019, 26, 17608 -17622.
AMA StyleTheodoros Grigoratos, Giorgio Martini, Massimo Carriero. An experimental study to investigate typical temperature conditions in fuel tanks of European vehicles. Environmental Science and Pollution Research. 2019; 26 (17):17608-17622.
Chicago/Turabian StyleTheodoros Grigoratos; Giorgio Martini; Massimo Carriero. 2019. "An experimental study to investigate typical temperature conditions in fuel tanks of European vehicles." Environmental Science and Pollution Research 26, no. 17: 17608-17622.
Despite that Heavy-Duty Vehicles (HDVs) represent a small part of the overall vehicle population they have been identified as one of the most important contributors to air pollution. This is one of the reasons why HDV emissions regulations are becoming more and more stringent worldwide. Following this trend, Europe introduced the Euro VI standard which includes more stringent emission limits for hydrocarbons, PM and NOx, while for the first time a limit for solid PN emissions was set. At the same time increased concern regarding greenhouse gas emissions led to a series of initiatives including HDVs CO2 certification and monitoring with the latest being the submission of a proposal for CO2 emission targets for 2025 and 2030. Despite the general concern, published data regarding Euro VI HDV emissions are scarce, while real-world emission factor measurements of regulated and unregulated pollutants are even more difficult to find. The main objective of this paper is to present real-world diesel Euro VI HDVs emissions of both gaseous pollutants and solid PN. For that reason five HDVs, including four trucks and one bus, were tested on-road under typical driving conditions. A breakdown of the emissions to low, medium, and high speed conditions was also performed with the aim investigating the performance of aftertreatment systems under different speed conditions. All tested vehicles performed better compared to older technology diesel HDVs, thus reflecting the technological improvements introduced over the last years. However, relatively high emissions were observed for some of the pollutants over low speed phases due to reduced effectiveness of the corresponding emission control systems. Calculated emission factors were also compared to existing emission inventories and good correlation was found for NOx, CO2 and solid PN emissions.
Theodoros Grigoratos; Georgios Fontaras; Barouch Giechaskiel; Nikiforos Zacharof. Real world emissions performance of heavy-duty Euro VI diesel vehicles. Atmospheric Environment 2019, 201, 348 -359.
AMA StyleTheodoros Grigoratos, Georgios Fontaras, Barouch Giechaskiel, Nikiforos Zacharof. Real world emissions performance of heavy-duty Euro VI diesel vehicles. Atmospheric Environment. 2019; 201 ():348-359.
Chicago/Turabian StyleTheodoros Grigoratos; Georgios Fontaras; Barouch Giechaskiel; Nikiforos Zacharof. 2019. "Real world emissions performance of heavy-duty Euro VI diesel vehicles." Atmospheric Environment 201, no. : 348-359.
Until now, a wide range of braking conditions has been applied in non‐exhaust emissions related studies. This often led to incomparable results and contradictory conclusions. Furthermore, there is no industry-wide accepted brake cycle available that represents real-world braking conditions. In this study a novel braking cycle is presented aiming towards a commonly accepted methodology for sampling and measuring brake wear particles. The cycle is based on the WLTP reference database, which includes in-use driving data from five different world regions with a total mileage of 740,000 km. The cycle development and statistical match to the WLTP database is presented. Experimental testing of the cycle both on the brake dynamometer and vehicle level are shown. Brake disc temperature behaviour on the real vehicle and dynamometer level is compared. It is shown that below a disc temperature of 160 °C, particle number emission is at background and sharply increases at brake temperatures above.
Marcel Mathissen; Jaroslaw Grochowicz; Christian Schmidt; Rainer Vogt; Ferdinand H. Farwick Zum Hagen; Tomasz Grabiec; Heinz Steven; Theodoros Grigoratos. A novel real-world braking cycle for studying brake wear particle emissions. Wear 2018, 414-415, 219 -226.
AMA StyleMarcel Mathissen, Jaroslaw Grochowicz, Christian Schmidt, Rainer Vogt, Ferdinand H. Farwick Zum Hagen, Tomasz Grabiec, Heinz Steven, Theodoros Grigoratos. A novel real-world braking cycle for studying brake wear particle emissions. Wear. 2018; 414-415 ():219-226.
Chicago/Turabian StyleMarcel Mathissen; Jaroslaw Grochowicz; Christian Schmidt; Rainer Vogt; Ferdinand H. Farwick Zum Hagen; Tomasz Grabiec; Heinz Steven; Theodoros Grigoratos. 2018. "A novel real-world braking cycle for studying brake wear particle emissions." Wear 414-415, no. : 219-226.
The Treadwear Rating (TWR) provided on the sidewall of the tyre is a marking intended to inform the customer about the expected durability of the tyre. The current study explores whether there is a correlation between the TWR and tyres' tread mass loss. Furthermore, it explores the possible correlation between the TWR and tyre wear dust emitted in the form of PM10 and PM2.5. For that reason, two tyres of the same brand (B) but with different TWR and three tyres of different brands (C and D with the same TWR as one of the B tyres and A with a lower TWR) were tested at a constant speed of 70 km/h by means of the Swedish National Road and Transport Research Institute (VTI) road simulator. Tyres of the same TWR but of different brands showed different behaviour in terms of material loss, PM, and PN emissions under the selected testing conditions. This means that it is not feasible to categorize tyres of different brands in terms of their emissions based on their TWR. The test performed on the two tyres of the same brand but with different TWR showed instead a substantial (not statistically significant) difference in both total wear and PM10 emissions. The tyre with the higher TWR (B2) showed less wear and PM10 emissions compared to the B1 tyre having a lower TWR. Since only two tyres of the same brand and with different TWR were tested, this result cannot be generalized and more tests are necessary to confirm the relation within the same brand. In general, the tyre tread mass loss showed no obvious statistical relation to PM10, PM2.5 or PN concentration. In all cases approximately 50% (by mass) of emitted PM10 fall within the size range of fine particles, while PN size distribution is dominated by nanoparticles most often peaking at 20–30 nm.
Theodoros Grigoratos; Mats Gustafsson; Olle Eriksson; Giorgio Martini. Experimental investigation of tread wear and particle emission from tyres with different treadwear marking. Atmospheric Environment 2018, 182, 200 -212.
AMA StyleTheodoros Grigoratos, Mats Gustafsson, Olle Eriksson, Giorgio Martini. Experimental investigation of tread wear and particle emission from tyres with different treadwear marking. Atmospheric Environment. 2018; 182 ():200-212.
Chicago/Turabian StyleTheodoros Grigoratos; Mats Gustafsson; Olle Eriksson; Giorgio Martini. 2018. "Experimental investigation of tread wear and particle emission from tyres with different treadwear marking." Atmospheric Environment 182, no. : 200-212.
This chapter tries to summarize the situation regarding existing regulation on brake and tire composition, worldwide. The most important pieces of legislation affecting brake composition include asbestos ban; REACH and REACH-like regulations; the European regulation on classification, labeling, and packaging of chemical substances and mixtures; and regional regulations related to restrictions on the use of trace elements and heavy metals. On the other hand, tire composition is driven mainly from REACH and REACH-like regulations, while it is also affected from the Global Automotive Declarable Substances List and International Material Data System. The most important chemical substances prohibited in brake manufacturing include asbestos, cadmium, chromium (VI), lead, and mercury, while in case of tires, polycyclic aromatic hydrocarbons.
Theodoros Grigoratos. Regulation on Brake/Tire Composition. Non-Exhaust Emissions 2018, 89 -100.
AMA StyleTheodoros Grigoratos. Regulation on Brake/Tire Composition. Non-Exhaust Emissions. 2018; ():89-100.
Chicago/Turabian StyleTheodoros Grigoratos. 2018. "Regulation on Brake/Tire Composition." Non-Exhaust Emissions , no. : 89-100.
The international journal of Aerosol and Air Quality Research (AAQR) covers all aspects of aerosol science and technology, atmospheric science and air quality related issues.
Katerina Papaoikonomou; Christina Emmanouil; Vasiliki Vasilato; Evangelia Diapouli; Theodoros Grigoratos; Antigoni Zafirakou; Athanasios Kungolos. PM10 and Elemental Concentrations in a Dismantling Plant for Waste of Electrical and Electronic Equipment in Greece. Aerosol and Air Quality Research 2018, 18, 1457 -1469.
AMA StyleKaterina Papaoikonomou, Christina Emmanouil, Vasiliki Vasilato, Evangelia Diapouli, Theodoros Grigoratos, Antigoni Zafirakou, Athanasios Kungolos. PM10 and Elemental Concentrations in a Dismantling Plant for Waste of Electrical and Electronic Equipment in Greece. Aerosol and Air Quality Research. 2018; 18 (6):1457-1469.
Chicago/Turabian StyleKaterina Papaoikonomou; Christina Emmanouil; Vasiliki Vasilato; Evangelia Diapouli; Theodoros Grigoratos; Antigoni Zafirakou; Athanasios Kungolos. 2018. "PM10 and Elemental Concentrations in a Dismantling Plant for Waste of Electrical and Electronic Equipment in Greece." Aerosol and Air Quality Research 18, no. 6: 1457-1469.
Theodoros Grigoratos; G. Martini. Development of a commonized methodology for measuring brake wear particles – current status within the PMP IWG. Proceedings 2017, 627 -627.
AMA StyleTheodoros Grigoratos, G. Martini. Development of a commonized methodology for measuring brake wear particles – current status within the PMP IWG. Proceedings. 2017; ():627-627.
Chicago/Turabian StyleTheodoros Grigoratos; G. Martini. 2017. "Development of a commonized methodology for measuring brake wear particles – current status within the PMP IWG." Proceedings , no. : 627-627.
Nikiforos Zacharof; Georgios Fontaras; Theodoros Grigoratos; Biagio Ciuffo; Dimitrios Savvidis; Oscar Delgado; J. Felipe Rodriguez. Estimating the CO2 Emissions Reduction Potential of Various Technologies in European Trucks Using VECTO Simulator. SAE Technical Paper Series 2017, 1, 1 .
AMA StyleNikiforos Zacharof, Georgios Fontaras, Theodoros Grigoratos, Biagio Ciuffo, Dimitrios Savvidis, Oscar Delgado, J. Felipe Rodriguez. Estimating the CO2 Emissions Reduction Potential of Various Technologies in European Trucks Using VECTO Simulator. SAE Technical Paper Series. 2017; 1 ():1.
Chicago/Turabian StyleNikiforos Zacharof; Georgios Fontaras; Theodoros Grigoratos; Biagio Ciuffo; Dimitrios Savvidis; Oscar Delgado; J. Felipe Rodriguez. 2017. "Estimating the CO2 Emissions Reduction Potential of Various Technologies in European Trucks Using VECTO Simulator." SAE Technical Paper Series 1, no. : 1.
E. Diapouli; M. Manousakas; S. Vratolis; V. Vasilatou; Thomas Maggos; Dikaia Saraga; Th Grigoratos; G. Argyropoulos; D. Voutsa; C. Samara; K. Eleftheriadis. Evolution of air pollution source contributions over one decade, derived by PM10 and PM2.5 source apportionment in two metropolitan urban areas in Greece. Atmospheric Environment 2017, 164, 416 -430.
AMA StyleE. Diapouli, M. Manousakas, S. Vratolis, V. Vasilatou, Thomas Maggos, Dikaia Saraga, Th Grigoratos, G. Argyropoulos, D. Voutsa, C. Samara, K. Eleftheriadis. Evolution of air pollution source contributions over one decade, derived by PM10 and PM2.5 source apportionment in two metropolitan urban areas in Greece. Atmospheric Environment. 2017; 164 ():416-430.
Chicago/Turabian StyleE. Diapouli; M. Manousakas; S. Vratolis; V. Vasilatou; Thomas Maggos; Dikaia Saraga; Th Grigoratos; G. Argyropoulos; D. Voutsa; C. Samara; K. Eleftheriadis. 2017. "Evolution of air pollution source contributions over one decade, derived by PM10 and PM2.5 source apportionment in two metropolitan urban areas in Greece." Atmospheric Environment 164, no. : 416-430.
The Western Macedonian Lignite Center (WMLC) in northwestern Greece is the major lignite center in the Balkans feeding four major power plants of total power exceeding 4 GW. Concentrations of PM10 (i.e., particulate matters with diameters ≤10 μm) are the main concern in the region, and the high levels observed are often attributed to the activities related to power generation. In this study, the contribution of fugitive dust emissions from the opencast lignite mines to the ambient levels of PM10 in the surroundings was estimated by performing chemical mass balance (CMB) receptor modeling. For this purpose, PM10 samples were concurrently collected at four receptor sites located in the periphery of the mine area during the cold and the warm periods of the year (November–December 2011 and August–September 2012), and analyzed for a total of 26 macro- and trace elements and ionic species (sulfate, nitrate, chloride). The robotic chemical mass balance (RCMB) model was employed for source identification/apportionment of PM10 at each receptor site using as inputs the ambient concentrations and the chemical profiles of various sources including the major mine operations, the fly ash escaping the electrostatic filters of the power plants, and other primary and secondary sources. Mean measured PM10 concentrations at the different sites ranged from 38 to 72 μg m−3. The estimated total contribution of mines ranged between 9 and 22% in the cold period increasing to 36–42% in the dry warm period. Other significant sources were vehicular traffic, biomass burning, and secondary sulfate and nitrate aerosol. These results imply that more efficient measures to prevent and suppress fugitive dust emissions from the mines are needed.
Constantini Samara; George Argyropoulos; Theodoros Grigoratos; Αthanasios Kouras; Εvangelia Manoli; Symela Andreadou; Fragkiskos Pavloudakis; Chariton Sahanidis. Chemical characterization and receptor modeling of PM10 in the surroundings of the opencast lignite mines of Western Macedonia, Greece. Environmental Science and Pollution Research 2017, 25, 12206 -12221.
AMA StyleConstantini Samara, George Argyropoulos, Theodoros Grigoratos, Αthanasios Kouras, Εvangelia Manoli, Symela Andreadou, Fragkiskos Pavloudakis, Chariton Sahanidis. Chemical characterization and receptor modeling of PM10 in the surroundings of the opencast lignite mines of Western Macedonia, Greece. Environmental Science and Pollution Research. 2017; 25 (13):12206-12221.
Chicago/Turabian StyleConstantini Samara; George Argyropoulos; Theodoros Grigoratos; Αthanasios Kouras; Εvangelia Manoli; Symela Andreadou; Fragkiskos Pavloudakis; Chariton Sahanidis. 2017. "Chemical characterization and receptor modeling of PM10 in the surroundings of the opencast lignite mines of Western Macedonia, Greece." Environmental Science and Pollution Research 25, no. 13: 12206-12221.
The European Commission is preparing a new regulatory initiative for monitoring CO2 emissions and fuel consumption of Heavy-Duty Vehicles in Europe. The new methodology is based on a combination of component testing and computer simulation of the vehicles' fuel consumption. A study was launched aiming to demonstrate that the approach is accurate and representative of the actual performance of vehicles. Experiments were conducted on two trucks, a 40 t Euro VI long haul truck and an 18 t Euro V rigid truck. Measurements were performed both on the chassis dyno and on the road. Simulation software was used for simulating the tests. Its ability to capture vehicle performance and fuel consumption was assessed against the measured data. Simulation results closely matched those of the dyno tests with the final simulated fuel consumption deviating by about ±2–4% compared to the measured value. Over the tests performed on the road, the final fuel consumption laid within a ±3.5% from the measurement. Given the variability of the actual measurement (σ ≥ 2%), it is concluded that a future official vehicle certification scheme can be based on this approach and achieve both high representativeness, compared to the vehicle's actual performance and high vehicle-to-vehicle, accuracy.
Georgios Fontaras; Theodoros Grigoratos; Dimitrios Savvidis; Konstantinos Anagnostopoulos; Raphael Luz; Martin Rexeis; Stefan Hausberger. An experimental evaluation of the methodology proposed for the monitoring and certification of CO2 emissions from heavy-duty vehicles in Europe. Energy 2016, 102, 354 -364.
AMA StyleGeorgios Fontaras, Theodoros Grigoratos, Dimitrios Savvidis, Konstantinos Anagnostopoulos, Raphael Luz, Martin Rexeis, Stefan Hausberger. An experimental evaluation of the methodology proposed for the monitoring and certification of CO2 emissions from heavy-duty vehicles in Europe. Energy. 2016; 102 ():354-364.
Chicago/Turabian StyleGeorgios Fontaras; Theodoros Grigoratos; Dimitrios Savvidis; Konstantinos Anagnostopoulos; Raphael Luz; Martin Rexeis; Stefan Hausberger. 2016. "An experimental evaluation of the methodology proposed for the monitoring and certification of CO2 emissions from heavy-duty vehicles in Europe." Energy 102, no. : 354-364.
A newly designed Compressed Natural Gas prototype engine was benchmarked against its parent Euro V compliant engine in terms of gaseous emissions and with particular view on regulated and Green House Gas emissions. The main technological innovation included a new cylinder head equipped with a Variable Valve Actuator system designed to increase the efficiency compared to the reference throttled engine. The objective of the study was to examine the effect of this system on the operation of the prototype engine. Engine stand-alone tests represented the first step of this analysis. Afterwards, both engines were installed on the same truck and tested under different operating conditions. Vehicle tests included measurements on a chassis dynamometer as well as on-road with the aim of verifying real-world emissions. CO2 emissions and Brake Specific Fuel Consumption of the prototype were lower compared to the reference engine, with this phenomenon being more pronounced on-road. Furthermore, reduced NOx and CO emissions were observed under all operating conditions. On the other hand, the introduction of the prototype engine had a negative effect on CH4 emissions. Despite that the prototype was initially designed to fulfill the EURO V standards, no pollutant exceeded the EURO VI limits over homologation cycles.
Theodoros Grigoratos; Georgios Fontaras; Giorgio Martini; Cesare Peletto. A study of regulated and green house gas emissions from a prototype heavy-duty compressed natural gas engine under transient and real life conditions. Energy 2016, 103, 340 -355.
AMA StyleTheodoros Grigoratos, Georgios Fontaras, Giorgio Martini, Cesare Peletto. A study of regulated and green house gas emissions from a prototype heavy-duty compressed natural gas engine under transient and real life conditions. Energy. 2016; 103 ():340-355.
Chicago/Turabian StyleTheodoros Grigoratos; Georgios Fontaras; Giorgio Martini; Cesare Peletto. 2016. "A study of regulated and green house gas emissions from a prototype heavy-duty compressed natural gas engine under transient and real life conditions." Energy 103, no. : 340-355.
We analyse the concentration of five trace elements (As, Cu, Ni, Pb and Zn) in the topsoil of the Kozani-Ptolemais basin where four coal-fired power plants run to provide almost 47.8 % of electricity requirements in Greece. We assume that if the power plants have altered the spatial (co)variation of the analysed elements through their toxic by-products, their effect would be observable only on a small spatial scale, since deposition of airborne pollutants is more evident if it is near the emission source. We used Factorial Cokriging to estimate the small-scale correlations among soil elements and to compare them to large spatial-scale correlations. Soil samples were collected from 92 sites. Given the low concentrations in soil heavy metals and As, we observed no serious soil contamination risk. We estimated correlations among the analysed elements on two spatial scales. On the larger scale, Ni and As exhibited higher correlation and received higher weights for the first regionalized factor, contrary to Cu, Pb and Zn which weighted more for the second regionalized factor. On the small spatial scale As associated with neither Ni nor other heavy metals. We conclude that soil arsenic has been altered by enrichment caused by some power plants through fly ash deposition and/or disposal. However, enrichment of soil elements was detectable only on the smaller spatial scale because anthropogenic inputs in soil through airborne emissions and subsequent deposition are evident only in the vicinity of the emission source.
Nikos Nanos; Theodoros Grigoratos; Jose Antonio Rodriguez Martin; Constantini Samara. Scale-dependent correlations between soil heavy metals and As around four coal-fired power plants of northern Greece. Stochastic Environmental Research and Risk Assessment 2014, 29, 1531 -1543.
AMA StyleNikos Nanos, Theodoros Grigoratos, Jose Antonio Rodriguez Martin, Constantini Samara. Scale-dependent correlations between soil heavy metals and As around four coal-fired power plants of northern Greece. Stochastic Environmental Research and Risk Assessment. 2014; 29 (6):1531-1543.
Chicago/Turabian StyleNikos Nanos; Theodoros Grigoratos; Jose Antonio Rodriguez Martin; Constantini Samara. 2014. "Scale-dependent correlations between soil heavy metals and As around four coal-fired power plants of northern Greece." Stochastic Environmental Research and Risk Assessment 29, no. 6: 1531-1543.
Traffic-related sources have been recognized as a significant contributor of particulate matter particularly within major cities. Exhaust and non-exhaust traffic-related sources are estimated to contribute almost equally to traffic-related PM10 emissions. Non-exhaust particles can be generated either from non-exhaust sources such as brake, tyre, clutch and road surface wear or already exist in the form of deposited material at the roadside and become resuspended due to traffic-induced turbulence. Among non-exhaust sources, brake wear can be a significant particulate matter (PM) contributor, particularly within areas with high traffic density and braking frequency. Studies mention that in urban environments, brake wear can contribute up to 55 % by mass to total non-exhaust traffic-related PM10 emissions and up to 21 % by mass to total traffic-related PM10 emissions, while in freeways, this contribution is lower due to lower braking frequency. As exhaust emissions control become stricter, relative contributions of non-exhaust sources—and therefore brake wear—to traffic-related emissions will become more significant and will raise discussions on possible regulatory needs. The aim of the present literature review study is to present the state-of-the-art of the different aspects regarding PM resulting from brake wear and provide all the necessary information in terms of importance, physicochemical characteristics, emission factors and possible health effects.
Theodoros Grigoratos; Giorgio Martini. Brake wear particle emissions: a review. Environmental Science and Pollution Research 2014, 22, 2491 -2504.
AMA StyleTheodoros Grigoratos, Giorgio Martini. Brake wear particle emissions: a review. Environmental Science and Pollution Research. 2014; 22 (4):2491-2504.
Chicago/Turabian StyleTheodoros Grigoratos; Giorgio Martini. 2014. "Brake wear particle emissions: a review." Environmental Science and Pollution Research 22, no. 4: 2491-2504.
Mercury (Hg) is a toxic element that is emitted to the atmosphere through human activities, mainly fossil fuel combustion. Hg accumulations in soil are associated with atmospheric deposition, while coal-burning power plants remain the most important source of anthropogenic mercury emissions. In this study, we analyzed the Hg concentration in the topsoil of the Kozani-Ptolemais basin where four coal-fired power plants (4,065 MW) run to provide 50 % of electricity in Greece. The study aimed to investigate the extent of soil contamination by Hg using geostatistical techniques to evaluate the presumed Hg enrichment around the four power plants. Hg variability in agricultural soils was evaluated using 276 soil samples from 92 locations covering an area of 1,000 km(2). We were surprised to find a low Hg content in soil (range 1-59 μg kg(-1)) and 50 % of samples with a concentration lower than 6 μg kg(-1). The influence of mercury emissions from the four coal-fired power plants on soil was poor or virtually nil. We associate this effect with low Hg contents in the coal (1.5-24.5 μg kg(-1)) used in the combustion of these power plants (one of the most Hg-poor in the world). Despite anthropic activity in the area, we conclude that Hg content in the agricultural soils of the Kozani-Ptolemais basin is present in low concentrations.
José Antonio Rodriguez Martin; Nikos Nanos; Theodoros Grigoratos; Gregoria Carbonell; Constantini Samara. Local deposition of mercury in topsoils around coal-fired power plants: is it always true? Environmental Science and Pollution Research 2014, 21, 10205 -10214.
AMA StyleJosé Antonio Rodriguez Martin, Nikos Nanos, Theodoros Grigoratos, Gregoria Carbonell, Constantini Samara. Local deposition of mercury in topsoils around coal-fired power plants: is it always true? Environmental Science and Pollution Research. 2014; 21 (17):10205-10214.
Chicago/Turabian StyleJosé Antonio Rodriguez Martin; Nikos Nanos; Theodoros Grigoratos; Gregoria Carbonell; Constantini Samara. 2014. "Local deposition of mercury in topsoils around coal-fired power plants: is it always true?" Environmental Science and Pollution Research 21, no. 17: 10205-10214.
The use of biofuels as automotive fuels is gradually increasing in order to meet the legislation targets for the use of renewable products in road fuels. Many types of bio-blending components are already used for this purpose throughout Europe with Fatty Acid Methyl Esters (FAMEs) being the most common. The objective of the present study was to evaluate the impact of Rapeseed Methyl Ester (RME) application on unregulated particulate emissions of modern diesel passenger vehicles, and specifically on exhaust particles’ most important chemical constituents. Particle emissions were analyzed for their soluble organic fraction (SOF) and its constituents (fuel-derived SOF and lube oil-derived SOF), as well as for major inorganic ions (nitrate, sulfate, ammonium). Furthermore, the impact of RME on SOF’s redox activity was investigated. A hydrocarbon-only diesel fuel (B0) and three blends of RME at 10%, 30% and 50% v/v were tested with three Euro 4 + compliant vehicles, one equipped with an oxidation catalyst and two others with different type of Diesel Particulate Filters (DPF), over the NEDC and Artemis Urban driving cycles. The use of higher biodiesel blends seem to result in increased SOF percentage to the total PM emitted. The same trend was also observed for fuel-derived SOF, while lube oil-derived SOF and major ion percentages to total PM were not significantly affected by the fuel change. Fuel-derived SOF was the major constituent comprising from 70% to 90% of the total SOF emitted. Additionally, in the non-DPF equipped vehicle the increase of biodiesel blend resulted in increased n-alkanes emissions (μg/km) without, however, the differences being statistically significant. Although the non-DPF equipped vehicle exhibited slightly higher sulfate than nitrate emissions, in DPF equipped vehicles sulfate were not detected at all. Higher RME contents resulted in elevated DTT-redox activity per mass in all tested vehicles, while on the other hand, the DTT-redox activity per unit of distance driven was not affected by the fuel change. Both DPF equipped vehicles exhibited 2–3 times higher DTT-redox activity per mass of emitted SOF when compared to the non-DPF equipped vehicle, however they exhibited 3–6 times lower oxidation activity per km, regardless the fuel. This is an indication that a significant amount of potentially more toxic organic compounds are trapped and oxidized in the DPF resulting thus in potentially less toxic organic emissions compared to the non-DPF equipped vehicle.
Theodoros Grigoratos; Georgios Fontaras; Maria Kalogirou; Constantini Samara; Zissis Samaras; Kenneth Rose. Effect of rapeseed methylester blending on diesel passenger car emissions – Part 2: Unregulated emissions and oxidation activity. Fuel 2014, 128, 260 -267.
AMA StyleTheodoros Grigoratos, Georgios Fontaras, Maria Kalogirou, Constantini Samara, Zissis Samaras, Kenneth Rose. Effect of rapeseed methylester blending on diesel passenger car emissions – Part 2: Unregulated emissions and oxidation activity. Fuel. 2014; 128 ():260-267.
Chicago/Turabian StyleTheodoros Grigoratos; Georgios Fontaras; Maria Kalogirou; Constantini Samara; Zissis Samaras; Kenneth Rose. 2014. "Effect of rapeseed methylester blending on diesel passenger car emissions – Part 2: Unregulated emissions and oxidation activity." Fuel 128, no. : 260-267.