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2020 ◽  
Vol 13 (11) ◽  
pp. 5827-5843
Author(s):  
Michal Vojtisek-Lom ◽  
Alessandro A. Zardini ◽  
Martin Pechout ◽  
Lubos Dittrich ◽  
Fausto Forni ◽  
...  

Abstract. We present an exploratory study carried out with a new miniature portable emission measurement system (Mini-PEMS) specifically designed at the Technical University of Liberec (CZ) for applications on two-wheeler vehicles owing to its reduced size (45cm×30×20cm) and weight (≈15 kg). It measures the exhaust gas concentrations of hydrocarbons and carbon mono- and dioxide with a nondispersive infrared method and nitrogen mono- and dioxides and oxygen using an electrochemical cell. In addition, the instrument acquires the engine speed, manifold absolute pressure, inlet and exhaust gas temperature, geo-localization, and vehicle speed. The exhaust mass flow rate is calculated from engine and emission data. The Mini-PEMS was validated on three two-wheelers (one moped and two motorcycles) against laboratory-grade instrumentation in the Vehicle Emissions Laboratory of the European Commission in terms of measured concentrations, exhaust flow, fuel consumption, and mass emission of pollutants. The mean absolute deviations of gas concentrations were 8 % for HC, 8 % for CO, 13 % for NOx, and 2 % for CO2, while the mass emissions (which include the exhaust flow determination uncertainty) were 7 % for HC, 7 % for CO, 9 % for NOx, and 5 % for CO2. An agreement of 2 % was achieved between the fuel consumption measured in the laboratory and calculated by the Mini-PEMS. As an application, the instrument was tested on board the vehicles during on-road trips. The emissions measured on the road were consistent among repeated runs, with differences between laboratory and on-road tests much larger than those between the Mini-PEMS and laboratory. We found similar or larger HC and NOx real-driving emissions and larger CO emissions from motorcycles and smaller ones for the moped. Considering its size and weight, the Mini-PEMS proved to be an efficient tool for vehicle monitoring, research and development and could be tested for in-service monitoring applications related to carbon monoxide and nitrogen oxides emissions. A tentative approach to characterize particulate mass and particle number was presented and compared to the existing filter method and nonvolatile particle number protocol.


2020 ◽  
Author(s):  
Michal Vojtisek-Lom ◽  
Alessandro A. Zardini ◽  
Martin Pechout ◽  
Lubos Dittrich ◽  
Fausto Forni ◽  
...  

Abstract. We present an exploratory study carried out with a new miniature portable emission measurement system (Mini-PEMS) specifically designed at the Technical University of Liberec (CZ) for applications on 2-wheeler vehicles owing to its reduced size (45 x 30 x 20 cm) and weight (≈ 15 kg). It measures the exhaust gas concentrations of hydrocarbons, carbon monoxide and dioxide with non-dispersive infrared method, nitrogen mono- and di-oxides and oxygen using an electrochemical cell. In addition, the instrument acquires the engine speed, the manifold absolute pressure, the inlet and exhaust gas temperature, the geo-localization and vehicle speed. The exhaust mass flow rate is calculated from engine and emission data. The Mini-PEMS was validated on three 2-wheelers (1 moped and 2 motorcycles) against laboratory-grade instrumentation in the Vehicle Emissions Laboratory of the European Commission in terms of measured concentrations, exhaust flow, fuel consumption and mass emission of pollutants. The mean absolute deviations of gas concentrations were 8 % for HC, 8 % for CO, 13 % for NOx and 2 % for CO2 while the mass emissions (which include the exhaust flow determination uncertainty) were 7 % for HC, 7 % for CO, 9 % for NOx and 5 % for CO2. An agreement of 2 % was achieved between the fuel consumption measured in the laboratory and calculated by the Mini-PEMS. As an application, the instrument was tested on board of the vehicles during on-road trips. The emissions measured on-road were consistent among repeated runs, with differences between laboratory and on-road tests much larger than those between Mini-PEMS and laboratory. We found similar or larger HC and NOx real-driving emissions, larger CO from motorcycles and smaller for the moped. Considering its size and weight, the Mini-PEMS proved to be an efficient tool for vehicle monitoring, research and development and could be tested for in-service monitoring applications related to carbon monoxide and nitrogen oxides emissions. A tentative approach to characterize particulate mass and particle number was presented and compared to the existing non-volatile particle number protocol.


2020 ◽  
Author(s):  
Michal Vojtisek-Lom ◽  
Alessandro A. Zardini ◽  
Martin Pechout ◽  
Lubos Dittrich ◽  
Fausto Forni ◽  
...  

2013 ◽  
Vol 21 (S1) ◽  
pp. 12-12 ◽  

Moxtek is the leading manufacturer of nano-optical and X-ray components, including high performance X-ray windows for demanding applications. AP3 ultra-thin polymer windows offer the highest transmission of low energy X-rays. Moxtek DuraBeryllium® windows are highly reliable, are resistance to moisture and harsh chemicals, and are available in thicknesses down to 8 μm. Moxtek also provides window solutions for sealed and flow proportional counters. Moxtek X-ray products (X-ray windows, X-ray JFETs, miniature/portable X-ray sources, X-ray detectors) enable compact handheld and benchtop elemental analysis for positive material identification. Moxtek products are used in various EDXRF systems for environmental screening, for hazardous substance analysis, and for sorting and recycling. Moxtek X-ray products are critical for optimal elemental analysis in electron microscopy, especially for low-Z elements. Moxtek strives to deliver products and services that meet or exceed customer requirements for performance, quality, and value.


Author(s):  
C. O. Rund

Residual surface stresses have been shown to play a critical role in the failure of metallic components through fatigue, stress corrosion cracking, and corrosion fatigue. A method of measuring these residual stresses remotely and nondestructively would improve the ability to assess the potential failure susceptibility of components in service.


1999 ◽  
Vol 76 (2) ◽  
pp. 228
Author(s):  
Ronald A. Bailey ◽  
Samuel C. Wait
Keyword(s):  

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