1,340 research outputs found
Exploring an Integrated System for Urban Stormwater Management: A Systematic Literature Review of Solutions at Building and District Scales
Climate change has aggravated the frequency and severity of extreme weather events, particularly in flood-related hazards. Cities nowadays face significant challenges in stormwater management from frequent heavy rainfalls. Traditional urban drainage systems can no longer cope with large amounts of surface runoff; cities are searching for new ways to deal with urban stormwater. Green roofs and other nature-based solutions have been widely used for stormwater management by combining water purification and retention functions but have not yet fully solved the flood problems. This article aims to (1) explore the different aspects of urban water management, particularly the urban stormwater topic, and (2) identify the existing solutions and discuss the potential and barriers to integrated solutions implementation. By introducing the concept of four domains and finding the overlapping area to investigate, we analyzed different solutions to reduce rainwater runoff from the roof and ground level, aiming at building and district scales. This paper proves that further research direction could constitute an integrated system to work together for urban stormwater management
Are the next-generation households ready for the energy transition? A survey on their positioning and practice with energy management tools
In the last decades, significant effort has been put towards technological advancement in housing for energy transition. Massive retrofitting actions have been called for, and innovative technologies for smart energy management at home have been deployed. However, undesired energy trends in housing suggest that relevant factors have been neglected. Among these, increasing importance is now given to occupants' behaviour, and their capacity to interact with energy management devices available in dwellings. This study investigates what is the position of next-generation users on energy transition at home. Two years ago, the authors launched a survey to explore people's awareness of energy use practices, interaction with metering devices, and user motivation to change when informed. As a pilot survey, over 300 people from the academy were involved to see what was the position of a sample which was supposed to be informed more than the average, in Italy. The test yielded early outcomes on how people become more interested to change as they gain knowledge and are offered suggestions. Despite the expectations, the sample's level of awareness was low. This suggested that a more user-centred approach is needed for wide-scale progress. Especially results from the youngest were below prospects. The questionnaire was relaunched to examine if the pandemic, energy crisis and latest news on climate change have affected positions of the youngsters. A testing session involving university students was performed, and results have been compared with the previous. As a result, reflections on the energy use patterns of the next-generation households are provided
Unification of X-ray winds in Seyfert galaxies: from ultra-fast outflows to warm absorbers
The existence of ionized X-ray absorbing layers of gas along the line of
sight to the nuclei of Seyfert galaxies is a well established observational
fact. This material is systematically outflowing and shows a large range in
parameters. However, its actual nature and dynamics are still not clear. In
order to gain insights into these important issues we performed a literature
search for papers reporting the parameters of the soft X-ray warm absorbers
(WAs) in 35 type 1 Seyferts and compared their properties to those of the
ultra-fast outflows (UFOs) detected in the same sample. The fraction of sources
with WAs is >60%, consistent with previous studies. The fraction of sources
with UFOs is >34%, >67% of which also show WAs. The large dynamic range
obtained when considering all the absorbers together allows us, for the first
time, to investigate general relations among them. In particular, we find
significant correlations indicating that the closer the absorber is to the
central black hole, the higher the ionization, column, outflow velocity and
consequently the mechanical power. The absorbers continuously populate the
whole parameter space, with the WAs and the UFOs lying always at the two ends
of the distribution. This strongly suggest that these absorbers, often
considered of different types, could actually represent parts of a single
large-scale stratified outflow observed at different locations from the black
hole. The observed parameters and correlations are consistent with both
radiation pressure through Compton scattering and MHD processes contributing to
the outflow acceleration, the latter playing a major role. Most of the
absorbers, especially the UFOs, have a sufficiently high mechanical power to
significantly contribute to AGN feedback.Comment: Manuscript updated to match the MNRAS published version. Link to the
related INAF news: http://www.media.inaf.it/2013/02/05/warm-absorbers
Superconductivity in Compressed Potassium and Rubidium
Calculations of the electron-phonon interaction in the alkali metals,
Potassium and Rubidium, using the results of band theory and BCS theory-based
techniques suggest that at high pressures K and Rb would be superconductors
with transition temperatures approaching 10 K.Comment: three figure
Effect of facade reflectance on outdoor microclimate: An Italian case study
Global warming affects the built environment with relation to its own characteristics, form, density. Heat waves effects would have limited effects if most of the cities would not be affected by Urban Heat Island that strongly increase their impacts (particularly on urban population). Does the choice of façade colours and materials contribute to this issue? The paper reports a research on a case study in Italy that tries to answer to this question comparing the trend in outdoor temperature increase closed to the building façade with relation to its colour and reflectance variations modelled by using Envi-met software. The outcomes point out that there is a correlation between the building façade reflectance and the temperature trend but this has a very limited influence on outdoor microclimate in open spaces as it varies in a range of less than 1°C
Energy Transition at Home: A Survey on the Data and Practices That Lead to a Change in Household Energy Behavior
Since energy transition depends significantly on reducing the built environment’s energy needs, many regulations and incentives have been implemented globally over the last three decades. Despite some positive results, many scholars suggest that households’ behavioral change could greatly accelerate progress. People’s levels of awareness and willingness to change, as well as the provision of feedback technologies, are important factors affecting the process. In spite of the extent of this body of literature, household consumption keeps rising. Our thesis is that the subject has been investigated without considering some important correlations among factors. Therefore, this study developed a survey to investigate actual consumers’ perspectives on the topic by combining people’s awareness of energy use, interaction with metering devices, and user motivation into a coherent framework. A testing session involving 500 people was held as a validation phase for a future large-scale launch of the questionnaire. The test yielded some early outcomes on how people become more interested in changing as they gain more knowledge and are offered suggestions. However, despite their supposedly advanced knowledge as educators and students, the sample’s level of awareness was low, suggesting that a more user-centered approach is needed for wide-scale progress
Collaborative research for transitioning to Climate-Neutral Cities - contouring a prospective framework for integrated planning
Transitioning to climate-neutral cities is difficult in practice, depending on complex urban activities and involving a vast range of stakeholders. Cities need ongoing support for assessing and implementing climate-neutral solutions. Following multi-country, collaborative academic workshops on this topic, we debate the use of new technologies and integrated planning approaches. We contour a preliminary framework underpinned by five key dimensions (urban nature; urban mobility; built form; energy; and circularity), triangulated with three research pillars: 1) citizen engagement, 2) city governance decision-making, supported by 3) digital technology. This essay proposes digital technologies as a bridge between bottom-up and top-down directions, challenges silo-thinking, and informs a cross-disciplinary, integrated climate-neutral planning process (in Europe)
Evolución del arbolado urbano en dunas bonaerenses
Los cambios espacio-temporales en la ocupación del territorio son procesos dinámicos que deben ser estudiados porque proporcionan la base para conocer las tendencias de los procesos de urbanización. El objetivo del trabajo fue realizar la zonificación geográfica de la evolución de cambios de la cobertura de territorial a partir de la tendencia temporal al sur del Municipio de Villa Gesell. Se realizó un análisis cluster con SIG de fotografías aéreas e imágenes satelitales de los años 1975 – 1997 y 2015, cuyos resultados expresan el aumento del arbolado urbano. Los cambios encontrados favorecieron el desarrollo del turismo con una mejora del paisaje y aportando un elemento blando de conexión entre las tres localidades del eje.The spatio-temporal changes in the occupation of the territory are dynamic processes that must be studied because they provide the base to know the tendencies of the processes of urbanization. The objective of the work was to carry out the geographical zoning of the evolution of changes in territorial coverage based on the temporal trend south of the Municipality of Villa Gesell. A cluster analysis was carried out with GIS of aerial photographs and satellite images of the years 1975 - 1997 and 2015, whose results express the increase of urban trees. The changes found favored the development of tourism with an improvement of the landscape and contributing a soft element of connection between the three localities.Fil: Gaspari, Fernanda J..
Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y ForestalesFil: Senisterra, Gabriela E..
Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y ForestalesFil: Rodriguez Vagaría, Alfonso.
Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y Forestale
Rainfall-runoff and curve number relationship under different conditions of soil´s: : ventania system modal basin, Argentina
La metodología del número de la curva (NC)
es la más empleada para transformar la precipitación
total en precipitación efectiva. De esta manera
se constituye en una herramienta de gran valor
para realizar estudios hidrológicos en cuencas
hidrográficas, fundamentalmente cuando hay una
deficiencia de registros extensos y confiables. Esta
metodología requiere del conocimiento del tipo y
uso de suelo de la cuenca en estudio y registros
pluviográficos. En el presente trabajo se aplicó el
procesamiento de imágenes LANDSAT para la
zonificación de la vegetación y uso del suelo en la
cuenca del Arroyo Pillahuinco Grande (38° LS y
61° 15' LW), ubicada sobre el sistema serrano de
La Ventana, en el sudoeste de la provincia de Buenos
Aires, Argentina. El análisis de su interrelación
generó los valores de NC y coeficiente de
escorrentía (CE). El procesamiento digital de la base
de datos raster georreferenciada se realizó con aplicación
de herramientas de sistema de información
geográfica (Idrisi Kilimanjaro). El análisis de regresión
múltiple efectuado a las variables generó un
R2 que explica el 89,77 % de la variabilidad de CE
(a < 0,01). Los resultados se exponen a nivel diagnóstico
y zonificación del NC, donde la mayor influencia
de la escorrentía se relaciona con las variables
cobertura vegetal y uso del suelo.The most used methodology to transformer
the storm rainfall in effective rain is the curve number
(CN). So, it's un useful tool to hydrologic studies in
hydrographic basin when there aren't enough
available registers. This methodology requires the
knowledge of type and use of soil and pluviographic
registers. We processed LANDSAT images to
zonification the soil use and vegetation of Pillahuinco
Grande basin (38° SL and 61° 15' WL). This basin
is sited at Sierra de La Ventana, South West of
Buenos Aires Province, Argentina. The analysis of
this rainfall-runoff relationship under different
conditions of soil's use generated values of CN and
runoff coefficient (EC). The digital data processing
raster was done using tool of System Information
Geographic (Idirisi Kilimanjaro). The multiple
regression analysis showed a R2 that explain the
89.77 % of EC variability (a < 0.01). The results are
showed at diagnostic level and CN zonation where
the most runoff influence is related with both variables
vegetal cover and use of soil.Fil: Gaspari, Fernanda J..Fil: Senisterra, Gabriela E..Fil: Marlats, Raúl M.
The relation between gas density and velocity power spectra in galaxy clusters: qualitative treatment and cosmological simulations
We address the problem of evaluating the power spectrum of the velocity field
of the ICM using only information on the plasma density fluctuations, which can
be measured today by Chandra and XMM-Newton observatories. We argue that for
relaxed clusters there is a linear relation between the rms density and
velocity fluctuations across a range of scales, from the largest ones, where
motions are dominated by buoyancy, down to small, turbulent scales:
, where
is the spectral amplitude of the density perturbations at wave number ,
is the mean square component of the velocity field,
is the sound speed, and is a dimensionless constant of order unity.
Using cosmological simulations of relaxed galaxy clusters, we calibrate this
relation and find . We argue that this value is set at
large scales by buoyancy physics, while at small scales the density and
velocity power spectra are proportional because the former are a passive scalar
advected by the latter. This opens an interesting possibility to use gas
density power spectra as a proxy for the velocity power spectra in relaxed
clusters, across a wide range of scales.Comment: 6 pages, 3 figures, submitted to ApJ Letter
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