scholarly journals Ultrafine particle dispersion in the metropolitan area of Guadalajara, Mexico

2020 ◽  
pp. 11-17
Author(s):  
Laura Peña-García ◽  
Celia Robles-Murguía ◽  
Roberto Maciel-Flores ◽  
José Rosas-Elguera
Keyword(s):  
Lung Tissue ◽  
Metropolitan Area ◽  
Urban Areas ◽  
Ultrafine Particle ◽  
Atomic Absorption Spectrophotometry ◽  
Particle Dispersion ◽  
Human Bronchus ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Mapping Analysis

Objectives: Dust, soil and leaf samples of Ficus benjamina were collected in the metropolitan area of Guadalajara (GMA) (Peña-García et al., 2017), allowing to identify the type of metallic particles, size, shape and spatial distribution. With the results obtained, the possible effects of metallic particles on human and plant health were discussed (Peña-García et al., 2019). Methodology: The sampling was in six municipalities of the GMA; Atomic absorption spectrophotometry analyses were carried out on leaves, which identified the presence of various elements that mostly exceeded the reference values. Through X-ray fluorescence, 23 elements were identified in soil, including Th and Ac in at least 14 sites. Using the scanning electron microscopy technique and elemental mapping analysis, coarse, fine and ultrafine metallic particles were identified in human bronchus and lung tissue, as well as fragments of cement, plastic, yeast and bacteria. The similarity between the metallic particles in the collected samples and those observed in lung tissue, warns of latent risks to the health of the GMA population. Contribution: The results obtained with the methodology used in this work allow us to glimpse the polluting potential in urban areas.

SREM observation of the interaction between the in-situ deposited Pd small particles and MgO cleavage surface

1986 ◽  
Vol 44 ◽  
pp. 382-383
Author(s):  
H.-J. Ou
Keyword(s):  
Electron Microscopy ◽  
Small Particle ◽  
Small Particles ◽  
Cleavage Surface ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Ceramic Surfaces ◽  
Reflection Electron Microscopy ◽  
New Perspective

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.

Bergsprungur og byggingar á höfuðborgarsvæðinu

2018 ◽  
Vol 24 ◽  
pp. 25-29
Author(s):  
Páll Einarsson ◽  
Haukur Jóhannesson ◽  
Ásta Rut Hjartardóttir
Keyword(s):  
Metropolitan Area ◽  
Urban Areas ◽  
Structural Damage ◽  
Seismic Waves ◽  
Relative Displacement ◽  
Building Structures ◽  
Engineering Structures ◽  
Volcanic System ◽  
Tectonic Plates ◽  
Building Practice

Straddling the boundary between two of the major tectonic plates on Earth, Iceland offers unique conditions for engineering structures that require special attention. Urban areas are rapidly expanding into areas where the bedrock is cut by numerous active fractures and faults. The fissure swarm of the Krísuvík volcanic system runs through the outskirts of Reykjavík and other towns of the metropolitan area. Activity of its fractures mostly occurs during magmatic events along the Reykjanes Peninsula oblique rift on a thousand years timescale. Hazard caused by the fractures is mostly twofold: Relative displacement of the walls of the fracture during magmatic intrusion and small relative displacements during the passage of seismic waves from distant earthquakes may damage structures built across them. The risk of structural damage may most likely be reduced considerably by avoiding building structures across the fractures. We suggest a change in building practice in fractures areas to achieve that.

scholarly journals Measurement of Light Absorbing Aerosols with Folded-Jamin Photothermal Interferometry

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2615 ◽  
Author(s):  
Jeonghoon Lee ◽  
Hans Moosmüller
Keyword(s):  
Refractive Index ◽  
Black Carbon ◽  
Metropolitan Area ◽  
Atmospheric Aerosols ◽  
Urban Areas ◽  
Photothermal Spectroscopy ◽  
Interferometric Technique ◽  
Carbon Particles ◽  
Black Carbon Aerosol ◽  
Absorbing Aerosols

In this study, a photothermal interferometer was developed, based on a folded-Jamin polarization instrument with refractive-index sensitive configuration, in order to characterize light-absorbing aerosols. The feasibility of our interferometric technique was demonstrated by performing photothermal spectroscopy characterizing spark-generated black carbon particles with atmospherically relevant concentrations and atmospheric aerosols in a metropolitan area. The sensitivity of this interferometric system for both laboratory-generated aerosols and atmospheric aerosols was ~ 1 (μg/m3)/μV, which is sufficient for the monitoring of black carbon aerosol in urban areas.

scholarly journals Formal and Informal Governance Arrangements to Boost Sustainable and Inclusive Rural-Urban Synergies: An Analysis of the Metropolitan Area of Styria

2020 ◽  
Vol 12 (24) ◽  
pp. 10637
Author(s):  
Theresia Oedl-Wieser ◽  
Kerstin Hausegger-Nestelberger ◽  
Thomas Dax ◽  
Lisa Bauchinger
Keyword(s):  
Metropolitan Area ◽  
Rural Areas ◽  
Urban Areas ◽  
City Region ◽  
Informal Governance ◽  
Governance Arrangement ◽  
Ability To Act ◽  
Uniform Region ◽  
The City ◽  
Governance Arrangements

In the past, the contrasts between rural and urban regions were the primary feature of analysis, while today, spatial dynamics are realized by the interactions between spaces and focus on the dependencies of rural-urban areas. This implies that boundaries are not anymore perceived as fixed but as flexible and fluid. With rising spatial interrelations, the concept of the “city-region” has been increasingly regarded as a meaningful concept for the implementation of development policies. Governance arrangements working at the rural-urban interface are often highly complex. They are characterized by horizontal and vertical coordination of numerous institutional public and private actors. In general, they provide opportunities to reap benefits and try to ameliorate negative outcomes but, due to asymmetric power relations, rural areas are often challenged to make their voice heard within city-region governance structures which can too easily become focused on the needs of the urban areas. This paper addresses these issues of rural-urban partnerships through the case of the Metropolitan Area of Styria. It presents analyses on the core issue of how to recognize the structure and driving challenges for regional co-operation and inter-communal collaboration in this city-region. Data were collected through workshops with regional stakeholders and interviews with mayors. Although the Metropolitan Area of Styria occupies an increased reference in policy discourses, the city-region has not grown to a uniform region and there are still major differences in terms of economic performance, the distribution of decision-making power, accessibility and development opportunities. If there should be established a stronger material and imagined cohesion in the city-region, it requires enhanced assistance for municipalities with less financial and personal resources, and tangible good practices of inter-municipal co-operation. The ability to act at a city-regional level depends highly on the commitment for co-operation in the formal and informal governance arrangement, and on the willingness for political compromises as well as on the formulation of common future goals.

scholarly journals Socio-Economy of Peri-Urban Areas: The Case of Lisbon Metropolitan Area

2016 ◽  
pp. 111-121
Author(s):  
Maria Fátima de Ferreiro ◽  
Sebastião Santos ◽  
Pedro Costa ◽  
Teresa Costa Pinto ◽  
Conceição Colaço
Keyword(s):  
Metropolitan Area ◽  
Urban Areas

scholarly journals Analysis of Self-Reported Walking for Transit in a Sprawling Urban Metropolitan Area in the Western U.S.

2019 ◽  
Vol 11 (3) ◽  
pp. 852 ◽  
Author(s):  
Courtney Coughenour ◽  
Hanns de la Fuente-Mella ◽  
Alexander Paz
Keyword(s):  
Metropolitan Area ◽  
Urban Areas ◽  
High Speed ◽  
Las Vegas ◽  
Local Level ◽  
Poisson Model ◽  
Active Transportation ◽  
Single Entry ◽  
Explicit Consideration ◽  
Design Characteristics

Walkability is associated with increased levels of physical activity and improved health and sustainability. The sprawling design of many metropolitan areas of the western U.S., such as Las Vegas, influences their walkability. The purpose of this study was to consider sprawl characteristics along with well-known correlates of walkability to determine what factors influence self-reported minutes of active transportation. Residents from four neighborhoods in the Las Vegas Metropolitan Area, targeted for their high and low walkability scores, were surveyed for their perceptions of street-connectivity, residential-density, land-use mix, and retail–floor-area ratio and sprawl characteristics including distance between crosswalks, single-entry-communities, high-speed streets, shade, and access to transit. A Poisson model provided the best estimates for minutes of active transportation and explained 11.28% of the variance. The model that included sprawl characteristics resulted in a better estimate of minutes of active transportation compared to the model without them. The results indicate that increasing walkability in urban areas such as Las Vegas requires an explicit consideration of its sprawl characteristics. Not taking such design characteristics into account may result in the underestimation of the influence of sprawl on active transportation and may result in a missed opportunity to increase walking. Understanding the correlates of walkability at the local level is important in successfully promoting walking as a means to increase active transportation and improve community health and sustainability.

SPATIAL DISTRIBUTION OF SULFUR DETERMINED BY PIXE IN THE ATMOSPHERE OF THE MEXICO CITY METROPOLITAN AREA

2012 ◽  
Vol 22 (01n02) ◽  
pp. 207-215
Author(s):  
F. ALDAPE ◽  
J. FLORES M ◽  
J. FLORES A ◽  
A. RETAMA-HERNÁNDEZ ◽  
O. RIVERA-HERNÁNDEZ
Keyword(s):  
Spatial Distribution ◽  
Mexico City ◽  
Metropolitan Area ◽  
Urban Areas ◽  
Fine Fraction ◽  
Federal District ◽  
Temporal Variations ◽  
Time Variability ◽  
Sample Collection ◽  
Sampling Network

An extensive investigation, aimed to study the fine fraction of airborne particulate matter (FAPM) in the Mexico City Metropolitan Area (MCMA), started in 2003, after the FAPM sampling network of the Environmental Secretariat of the Federal District Government (Secretaría del Medio Ambiente del Gobierno del Distrito Federal, SMA-GDF) was put into operation. Formerly, several research institutions in Mexico, in collaboration with the local government, made continuous efforts during the last two decades, in order to improve air quality in the MCMA. Samples have been collected using US-EPA designated samplers, following the same agency protocols. In this study, 922 samples were analyzed by PIXE in order to determine the elemental concentrations (ng/m3) of the FAPM. The samples were collected every three days by the Atmospheric Sampling Network (Red Automática de Monitoreo Atmosférico, RAMA) of the SMA-GDF, starting by the end of 2003 and along 2004 on three sites, and during the whole 2005 to the beginning of 2006 in seven stations, taking samples every six days during this last stage. The sample collection has continued up to date at the latter pace. The results obtained have allowed determining the sulfur (S) spatial distribution over the area, showing a reasonable uniformity in space, but well marked time variability. The S spatial distribution has also showed similar patterns between equivalent seasons from year to year, although not a strict periodicity. Compared to other elements found consistently in the samples, S is mainly distributed over the area by a large amount of mobile (mainly transportation) sources, fairly distributed over it, while other elements come from fixed sources located at industrial or urban areas. Comparisons were also made among the sampling sites, and among the three climatic seasons (drycold, dry-hot and rain) from year to year. Correlations between temporal variations of pairs of sampling sites were also calculated for S and other elements, in order to support these conclusions.

scholarly journals Hydrometeorological Monitoring Using Opportunistic Sensing Networks in the Amsterdam Metropolitan Area

2020 ◽  
Vol 101 (2) ◽  
pp. E167-E185 ◽  
Author(s):  
L. W. de Vos ◽  
A. M. Droste ◽  
M. J. Zander ◽  
A. Overeem ◽  
H. Leijnse ◽  
...  
Keyword(s):  
Metropolitan Area ◽  
Urban Areas ◽  
Environmental Variables ◽  
Added Value ◽  
Heat Island ◽  
Opportunistic Sensing ◽  
Urban Heat ◽  
Weather Stations ◽  
Using Data ◽  
Commercial Microwave Links

Abstract The ongoing urbanization and climate change urges further understanding and monitoring of weather in cities. Two case studies during a 17-day period over the Amsterdam metropolitan area, the Netherlands, are used to illustrate the potential and limitations of hydrometeorological monitoring using nontraditional and opportunistic sensors. We employ three types of opportunistic sensing networks to monitor six important environmental variables: 1) air temperature estimates from smartphone batteries and personal weather stations, 2) rainfall from commercial microwave links and personal weather stations, 3) solar radiation from smartphones, 4) wind speed from personal weather stations, 5) air pressure from smartphones and personal weather stations, and 6) humidity from personal weather stations. These observations are compared to dedicated, traditional observations where possible, although such networks are typically sparse in urban areas. First, we show that the passage of a front can be successfully monitored using data from several types of nontraditional sensors in a complementary fashion. Also, we demonstrate the added value of opportunistic measurements in quantifying the urban heat island (UHI) effect during a hot episode. The UHI can be clearly determined from personal weather stations, though UHI values tend to be high compared to records from a traditional network. Overall, this study illustrates the enormous potential for hydrometeorological monitoring in urban areas using nontraditional and opportunistic sensing networks.

scholarly journals Electoral behaviour in the Kraków metropolitan area: 1993–2011

2017 ◽  
Vol 35 (35) ◽  
pp. 65-80
Author(s):  
Radosław Linkowski
Keyword(s):  
Metropolitan Area ◽  
Rural Areas ◽  
Urban Areas ◽  
Political Change ◽  
The Political ◽  
Voting Behaviour ◽  
Economic Changes ◽  
Parliamentary Elections ◽  
Electoral Behaviour ◽  
The City

Abstract The purpose of the paper is to describe changes in support for the four principal political options (‘right’, ‘left’, ‘liberal’, ‘peasant’) available in the Kraków Metropolitan Area (KMA) in parliamentary elections in the period 1993–2011. The electoral behaviour of the residents of the various KMA zones became increasingly similar in the study period. The political ‘distance’ between the northern commuter zone of the KMA (part of the Russian partition in the 19th c.) and the rest of the KMA, decreased significantly. The suburban zone of Kraków also changed over the course of the study period by becoming significantly similar to the city in terms of voting behaviour. This political change was largely due to substantial social and economic changes in the rural parts of the metropolitan area. Urban areas in the KMA were much more stable in their voting patterns and tended to politically resemble one another much more than rural areas. The city of Kraków and the southern part of its commuter zone – part of the Austrian partition in the 19th c. – were characterized by fewer fluctuations in voting behaviour than the two remaining parts of the KMA.

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