scholarly journals Assessment of vertically-resolved PM<sub>10</sub> from mobile lidar observations

2009 ◽  
Vol 9 (3) ◽  
pp. 13475-13521 ◽  
Author(s):  
J.-C. Raut ◽  
P. Chazette
Keyword(s):  
Cross Sections ◽  
Spatiotemporal Variability ◽  
Horizontal Gradient ◽  
Particulate Pollution ◽  
Paris Area ◽  
Surface Measurements ◽  
Surface Network ◽  
Set Up ◽  
Lidar Observations ◽  
Mass Concentrations

Abstract. We investigate in this study the role of the Paris Peripherique (the ring around Paris agglomeration) in local particulate pollution and the horizontal gradient of pollution between Paris centre and its remote suburbs. For this purpose, we combine in situ surface measurements with active remote sensing observations obtained from a great number of research programs in Paris area since 1999. Two approaches, devoted to the conversion of vertical profiles of lidar-derived extinction coefficients into PM10, have been set up. A very good agreement is found between the theoretical and empirical methods with a discrepancy of 3%. Hence, specific extinction cross-sections at 355 nm are provided with a reasonable uncertainty for urban (4.5 m2/g), periurban (5.9 m2/g), rural (7.1 m2/g), biomass burning (2.6 m2/g) and dust (1.1 m2/g) aerosols. The high spatial and temporal resolutions of the mobile lidar (respectively 1.5 m and 1 min) enable to follow the spatiotemporal variability of various layers carrying aerosols in the troposphere. Appropriate specific extinction cross-sections are applied in each layer detected in the vertical heterogeneities from the lidar profiles. The standard deviation between lidar-derived PM10 at 200 m above ground and surface network stations measurements was ~14 μg m−3. This difference is particularly ascribed to a decorrelation of mass concentrations in the first meters of the boundary layer, as highlighted through multiangular lidar observations. Lidar signals can be used to follow mass concentrations at the surface and provide useful information on PM10 peak forecasting that affect air quality.

scholarly journals Assessment of vertically-resolved PM<sub>10</sub> from mobile lidar observations

2009 ◽  
Vol 9 (21) ◽  
pp. 8617-8638 ◽  
Author(s):  
J.-C. Raut ◽  
P. Chazette
Keyword(s):  
Cross Sections ◽  
Urban Areas ◽  
Spatiotemporal Variability ◽  
Paris Area ◽  
Surface Measurements ◽  
Surface Network ◽  
Set Up ◽  
Outlying Regions ◽  
Lidar Observations ◽  
Mass Concentrations

Abstract. We investigate in this study the vertical PM10 distributions from mobile measurements carried out from locations along the Paris Peripherique (highly trafficked beltway around Paris), examine distinctions in terms of aerosol concentrations between the outlying regions of Paris and the inner city and eventually discuss the influence of aerosol sources, meteorology, and dynamics on the retrieved PM10 distributions. To achieve these purposes, we combine in situ surface measurements with active remote sensing observations obtained from a great number of research programs in Paris area since 1999. Two approaches, devoted to the conversion of vertical profiles of lidar-derived extinction coefficients into PM10, have been set up. A very good agreement is found between the theoretical and empirical methods with a discrepancy of 3%. Hence, specific extinction cross-sections at 355 nm are provided with a reasonable relative uncertainty lower than 12% for urban (4.5 m2 g−1) and periurban (5.9 m2 g−1) aersols, lower than 26% for rural (7.1 m2 g−1) aerosols, biomass burning (2.6 m2 g−1) and dust (1.1 m2 g−1) aerosols The high spatial and temporal resolutions of the mobile lidar (respectively 1.5 m and 1 min) enable to follow the spatiotemporal variability of various layers trapping aerosols in the troposphere. Appropriate specific extinction cross-sections are applied in each layer detected in the vertical heterogeneities from the lidar profiles. The standard deviation (rms) between lidar-derived PM10 at 200 m above ground and surface network stations measurements was ~14μg m−3. This difference is particularly ascribed to a decorrelation of mass concentrations in the first meters of the boundary layer, as highlighted through multiangular lidar observations. Lidar signals can be used to follow mass concentrations with an uncertainty lower than 25% above urban areas and provide useful information on PM10 peak forecasting that affect air quality.

scholarly journals Computer-aided design of multi-purpose steel headframes for mines with a new technical level

2020 ◽  
Vol 174 ◽  
pp. 01048
Author(s):  
Elena Kassikhina ◽  
Vladimir Pershin ◽  
Nina Rusakova
Keyword(s):  
Cross Sections ◽  
Computer Aided Design ◽  
Information Technologies ◽  
Three Dimensional ◽  
Numerical Control ◽  
Technical Level ◽  
Resource Saving ◽  
Existing Structures ◽  
Set Up ◽  
Aided Design

The existing structures of the steel sinking headgear and permanent headframe do not meet the requirements of resource saving (metal consumption and manpower input at installation), and the present methods of the headframe designing do not fully reflect recent possibilities of applying of the advanced information technologies. Technical level of the modern software makes it possible for designers to set up multiple numerical experiments to create a computer simulation that allows solving the problem without field and laboratory experiments, and therefore without special costs. In this regard, a mathematical simulation has been developed and based on it, software to select cross-sections of multi- purpose steel headframe elements and to calculate proper weight of its metal structures depending on the characteristics and hoisting equipment. A headframe drawing is displayed, as the results of the software work, including list of elements, obtained optimal hoisting equipment in accordance with the initial data. The software allows speeding up graphic work and reducing manpower input on calculations and paper work. The software allows developing a three-dimensional image of the structure and its functional blocks, based on the obtained initial parameters, as well as developing control software for units with numerical control (NC) in order to manufacture multi-purpose headframes.

scholarly journals Imaging the Subsurface: How Different Visualizations of Cross-sections Affect the Sense of Uncertainty

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Ane Bang-Kittilsen ◽  
Terje Midtbø
Keyword(s):  
Cross Sections ◽  
Open Data ◽  
Question Mark ◽  
Reference Information ◽  
Geological Information ◽  
Crucial Information ◽  
Set Up ◽  
Web Experiment ◽  
The Right ◽  
Visualization Techniques

AbstractGeologists struggle to communicate the uncertainty that arise when mapping and interpreting the geological subsurface. Today, open data sharing policies make new value of geological information possible for a broader user group of non-experts. It is crucial to develop standard methods for visualizing uncertainty to increase the usability of geological information. In this study, a web experiment was set up to analyze whether and how different design choices influence the sense of uncertainty. Also, questions about the intuitiveness of symbols were asked. Two-hundred ten participants from different countries completed the experiment, both experts and non-experts in geology. Traditional visualization techniques in geology, like dashed lines, dotted lines and question mark, were tested. In addition, other visualizations were tested, such as hatched area and variations of symbol size, zoom levels and reference information. The results show that design choices have an impact on the participants’ assessment of uncertainty. The experts inquire about crucial information if it is not present. The results also suggest that when visualizing uncertainty, all the elements in the representation, and specifically the line and area symbols that delineate and colour the features, must work together to make the right impression.

Glass-Alumina Functionally Graded Materials Produced by Plasma Spraying

2007 ◽  
Vol 333 ◽  
pp. 227-230
Author(s):  
Valeria Cannillo ◽  
Luca Lusvarghi ◽  
Tiziano Manfredini ◽  
M. Montorsi ◽  
Cristina Siligardi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Plasma Spraying ◽  
Functionally Graded Materials ◽  
Cross Sections ◽  
Functionally Graded ◽  
Depth Sensing ◽  
Graded Materials ◽  
Set Up ◽  
Scanning Electron

The present work was focused on glass-alumina functionally graded materials. The samples, produced by plasma spraying, were built as multi-layered systems by depositing several layers of slightly different composition, since their alumina and glass content was progressively changed. After fabricating the graded materials, several, proper characterization techniques were set up to investigate the gradient in composition, microstructure and related performances. A particular attention was paid to the observation of the graded cross sections by scanning electron microscopy, which allowed to visualize directly the graded microstructural changes. The scanning electron microscopy (SEM) inspection was integrated with accurate mechanical measurements, such as systematic depth-sensing Vickers microindentation tests performed on the graded cross sections.

scholarly journals Exploring the relation between aerosol optical depth and PM<sub>2.5</sub> at Cabauw, the Netherlands

2008 ◽  
Vol 8 (5) ◽  
pp. 17939-17986 ◽  
Author(s):  
M. Schaap ◽  
A. Apituley ◽  
R. M. A. Timmermans ◽  
R. B. A. Koelemeijer ◽  
G. de Leeuw
Keyword(s):  
The Netherlands ◽  
Ground Level ◽  
Weather Conditions ◽  
Fair Weather ◽  
Modis Aod ◽  
Data Points ◽  
Set Up ◽  
The Relationship ◽  
Lidar Observations ◽  
Pm2.5 Concentration

Abstract. To acquire daily estimates of PM2.5 distributions based on satellite data one depends critically on an established relation between AOD and ground level PM2.5. In this study we aimed to experimentally establish the AOD-PM2.5 relationship for the Netherlands. For that purpose an experiment was set-up at the AERONET site Cabauw. The average PM2.5 concentration during this ten month study was 18 μg/m3, which confirms that the Netherlands are characterised by a high PM burden. A first inspection of the AERONET level 1.5 (L1.5) AOD and PM2.5 data at Cabauw showed a low correlation between the two properties. However, after screening for cloud contamination in the AERONET L1.5 data, the correlation improved substantially. When also constraining the dataset to data points acquired around noon, the correlation between AOD and PM2.5 amounted to R2=0.6 for situations with fair weather. This indicates that AOD data contain information about the temporal evolution of PM2.5. We had used LIDAR observations to detect residual cloud contamination in the AERONET L1.5 data. Comparison of our cloud-screed L1.5 with AERONET L2 data that became available near the end of the study showed favorable agreement. The final relation found for Cabauw is PM2.5=124.5*AOD–0.34 (with PM2.5 in μg/m3) and is valid for fair weather conditions. The relationship determined between MODIS AOD and ground level PM2.5 at Cabauw is very similar to that based on the much larger dataset from the sun photometer data, after correcting for a systematic overestimation of the MODIS data of 0.05. We applied the relationship to a MODIS composite map to assess the PM2.5 distribution over the Netherlands. Spatial dependent systematic errors in the MODIS AOD, probably related to variability in surface reflectance, hamper a meaningful analysis of the spatial distribution of PM2.5 using AOD data at the scale of the Netherlands.

scholarly journals Development of an experimental set-up for the measurement of neutron-induced fission and capture cross sections of highly radioactive fissile nuclei

2014 ◽  
Vol 69 ◽  
pp. 00005 ◽  
Author(s):  
Iulia Companis ◽  
Ludovic Mathieu ◽  
Mourad Aïche ◽  
Peter Schillebeeckx ◽  
Jan Heyse ◽  
...  
Keyword(s):  
Cross Sections ◽  
Capture Cross ◽  
Induced Fission ◽  
Set Up ◽  
Capture Cross Sections

UPGRADE FOR THE CBELSA/TAPS EXPERIMENT AT ELSA FOR η AND η′ DECAYS

2010 ◽  
Vol 19 (05n06) ◽  
pp. 938-945 ◽  
Author(s):  
◽  
MICHAEL LANG
Keyword(s):  
Cross Sections ◽  
Major Part ◽  
Charged Particles ◽  
Final State ◽  
Accelerator Facility ◽  
Neutral Particles ◽  
Tracking Detector ◽  
Set Up ◽  
Photo Production

The CBELSA/TAPS experiment is a set up installed at the accelerator facility ELSA in Bonn. It is used to measure cross sections of hadronic reactions by observing final state particles. The set up is well suited for the identification of neutral particles such as neutrons and photons (e.g. from π0 decay). It is planed to access the major part of η and η′ photo production and decays as also strangeness. This requires a neutral trigger capability for the detector set up and a tracking detector for charged particles.

scholarly journals Micro-moulded substrates for the analysis of structure-dependent behaviour of nematodes

Nematology ◽  
2004 ◽  
Vol 6 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Kazunori Otobe ◽  
Kenji Itou ◽  
Takayuki Mizukubo
Keyword(s):  
Cross Sections ◽  
Pore Space ◽  
Flat Glass ◽  
Glass Plate ◽  
Micro Channel ◽  
Channel Network ◽  
Migratory Activity ◽  
Set Up ◽  
Serial Images ◽  
Dependent Behaviour

AbstractMicrostructures, consisting of networks of channels of rectangular cross sections (50 μm high, 40-200 μm wide), were formed in 5 mm square areas on transparent substrates made of silicon rubber. An experimental set-up using the network sealed with a flat glass plate has the potential to function in a way similar to the pore space in soil, and is therefore useful for studies of nematode migration. The set-up allowed the migratory activity of nematodes in water-filled, porous and transparent microstructures to be observed with a microscope. By means of substrates with two different channel dimensions, the structure-dependent behaviour of second-stage juveniles of Meloidogyne incognita was visually demonstrated. Their behaviour was examined on the basis of the migration patterns obtained by superimposing recorded serial images of individual juveniles. In a micro-channel network with 40 μm high channels of 200 μm wide elements, juveniles showed marked activity in migration, forming consistent zigzag patterns spread over the network area. In contrast, in a micro-channel network with 80 μm high channels of 400 μm wide elements, migration showed thick, sparse patterns, restricted around the area where the juveniles were initially deposited. This comparison showed that M. incognita juveniles in a narrow, fine network tended to migrate actively and, in contrast, those in a wide, coarse network were prevented from migrating by the network configuration.

scholarly journals Towards a unified description of the electroweak nuclear response

2015 ◽  
Vol 24 (06) ◽  
pp. 1530006 ◽  
Author(s):  
Omar Benhar ◽  
Alessandro Lovato
Keyword(s):  
Cross Sections ◽  
Compact Stars ◽  
Kinematical Region ◽  
Many Body ◽  
Unified Framework ◽  
Many Body Theory ◽  
Atomic Nuclei ◽  
Set Up ◽  
Body Theory ◽  
Nuclear Many Body Theory

We briefly review the growing efforts to set up a unified framework for the description of neutrino interactions with atomic nuclei and nuclear matter, applicable in the broad kinematical region corresponding to neutrino energies ranging between few MeV and few GeV. The emerging picture suggests that the formalism of nuclear many-body theory (NMBT) can be exploited to obtain the neutrino-nucleus cross-sections needed for both the interpretation of oscillation signals and simulations of neutrino transport in compact stars.

scholarly journals Culling a Set of Points for Roundness or Cylindricity Evaluations

2003 ◽  
Vol 13 (03) ◽  
pp. 231-240 ◽  
Author(s):  
Olivier Devillers ◽  
Franco P. Preparata
Keyword(s):  
Cross Sections ◽  
Input Data ◽  
Linear Time ◽  
Programming Approach ◽  
Fixed Size ◽  
Recent Approach ◽  
Data Points ◽  
Surface Measurements ◽  
Computational Metrology ◽  
Set Of Points

Roundness and cylindricity evaluations are among the most important problems in computational metrology, and are based on sets of surface measurements (input data points). A recent approach to such evaluations is based on a linear-programming approach yielding a rapidly converging solution. Such a solution is determined by a fixed-size subset of a large input set. With the intent to simplify the main computational task, it appears desirable to cull from the input any point that cannot provably define the solution. In this note we present an analysis and an efficient solution to the problem of culling the input set. For input data points arranged in cross-sections under mild conditions of uniformity, this algorithm runs in linear time.

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