5,451 research outputs found
The cool core state of Planck SZ-selected clusters versus X-ray selected samples: evidence for cool core bias
We characterized the population of galaxy clusters detected with the SZ
effect with Planck, by measuring the cool core state of the objects in a
well-defined subsample of the Planck catalogue. We used as indicator the
concentration parameter Santos et al. (2008). The fraction of cool core
clusters is and does not show significant indications of
evolution in the redshift range covered by our sample. We compare the
distribution of the concentration parameter in the Planck sample with the one
of the X-ray selected sample MACS (Mann & Ebeling, 2011): the distributions are
significantly different and the cool core fraction in MACS is much higher (). Since X-ray selected samples are known to be biased towards cool
cores due to the presence of their prominent surface brightness peak, we
simulated the impact of the "cool core bias" following Eckert et al. (2011). We
found that it plays a large role in the difference between the fractions of
cool cores in the two samples. We examined other selection effects that could
in principle bias SZ-surveys against cool cores but we found that their impact
is not sufficient to explain the difference between Planck and MACS. The
population of X-ray under-luminous objects, which are found in SZ-surveys but
missing in X-ray samples (Planck Collaboration 2016), could possibly contribute
to the difference, as we found most of them to be non cool cores, but this
hypothesis deserves further investigation.Comment: Accepted for publication in MNRA
SURVEY, HBIM AND CONSERVATION PLAN OF A MONUMENTAL BUILDING DAMAGED BY EARTHQUAKE
open4Oreni, D.; Brumana, R.; Della Torre, S.; Banfi, F.Oreni, Daniela; Brumana, Raffaella; DELLA TORRE, Stefano; Banfi, Fabrizi
Spatial and temporal hot spots of Aedes albopictus abundance inside and outside a South European metropolitan area
Aedes albopictus is a tropical invasive species which in the last decades spread worldwide,
also colonizing temperate regions of Europe and US, where it has become a public health
concern due to its ability to transmit exotic arboviruses, as well as severe nuisance problems
due to its aggressive daytime outdoor biting behaviour. While several studies have
been carried out in order to predict the potential limits of the species expansions based on
eco-climatic parameters, few studies have so far focused on the specific effects of these
variables in shaping its micro-geographic abundance and dynamics. The present study
investigated eco-climatic factors affecting Ae. albopictus abundance and dynamics in metropolitan
and sub-urban/rural sites in Rome (Italy), which was colonized in 1997 and is nowadays
one of the most infested metropolitan areas in Southern Europe. To this aim,
longitudinal adult monitoring was carried out along a 70 km-transect across and beyond the
most urbanized and densely populated metropolitan area. Two fine scale spatiotemporal
datasets (one with reference to a 20m circular buffer around sticky traps used to collect
mosquitoes and the second to a 300m circular buffer within each sampling site) were
exploited to analyze the effect of climatic and socio-environmental variables on Ae. albopictus
abundance and dynamics along the transect. Results showed an association between
highly anthropized habitats and high adult abundance both in metropolitan and sub-urban/
rural areas, with “small green islands” corresponding to hot spots of abundance in the metropolitan
areas only, and a bimodal seasonal dynamics with a second peak of abundance in
autumn, due to heavy rains occurring in the preceding weeks in association with permissive
temperatures. The results provide useful indications to prioritize public mosquito control
measures in temperate urban areas where nuisance, human-mosquito contact and risk of
local arbovirus transmission are likely higher, and highlight potential public health risks also
after the summer months typically associated with high mosquito densities
HBIM challenge among the paradigm of complexity, tools and preservation: The Basilica di Collemaggio 8 years after the earthquake (L'Aquila)
In December 2012 ENIservizi (the Italian multi-national energy agency operating in many countries), after the Earthquake that occurred in April 2009, decided to undertake the project 'Re-start from Collemaggio' with the aim of giving new hope to the L'Aquila community, funding around 14 million Euro to restore the Basilica di Collemaggio. The Superintendence Office carried on the restoration project with the scientific support of the Università degli Studi de L'Aquila and the Università La Sapienza di Roma, under the coordination of the Politecnico di Milano. ENIservizi, aware of the BIM potential in the complex building and infrastructure domain in the world, required an advanced HBIM from the laser scanner and photogrammetric surveying to support the diagnostic analysis, the design project, the tender and the restoration itself, today still on course. Plans and vertical sections were delivered (2012) starting from the surveying campaigns (February and June 2013), together with the first HBIM advancement from the end of 2012 in support of the preliminary-definitive-executive steps of the restoration design project (2013-14-15). Five years later, this paper tries to make a synthesis of the different lessons learnt, in addition to the positive and critical aspects relating HBIM feasibility, sustainability and usefulness to the challenging restoration work. In particular, the Collemaggio BIM experience anticipated the new Italian Public Procurement Legislation (D.Lgs 50/2016, Nuovo Codice degli Appalti pubblici) aligned with to the EUPPD 24/2014: The EU Directive on Public Procurement asked all the 28 EU countries to adopt building informative modelling by February 2016 in order to support the whole LCM (Life Cycle Management), starting from the project and the intervention, through rewarding scores or mandatory regulations. Many analyses foresees to save from around 5% to 15% of the overall investment by adopting mature BIM (Level 3 to 5), particularly 4D remotely controlled BIM in support of the LCM, as in the case of maintenance and management process. The tender for Basilica restoration was published in 2015: The process was not developed enough to introduce selective criteria based on BIM adoption by the Construction Industry due to the lack of legislation at that time and the lack of BIM skills among the companies. Nevertheless ENIservizi also separately funded aside the HBIM of the Basilica to tackle an advanced BIM able to address decision-making processes in the heritage domain among the different actors: To support operators, architects, structural engineers, economic computation, construction site management and restoration, the theoretical and practical approach adopted by the HBIM, overcame the current logic based on sequential LoD (from simplex to complex, from the preliminary to the executive design) that is typical of new constructions in favour of a complex LoD approach that could guarantee management of the richness, unicity and multiplicity of each component and the maximum degree of knowledge in order to derive the decisions from the starting phases of the project. On the lesson learnt from this experience, the process of updating the current codification criteria (UNI11337-2009) was started with a draft proposal stimulating a debate for the future of HBIM adoption
Stochastic model of hysteresis
The methods of the probability theory have been used in order to build up a
new model of hysteresis. It turns out that the reversal points of the control
parameter (e. g., the magnetic field) are Markov points which determine the
stochastic evolution of the process. It has been shown that the branches of the
hysteresis loop are converging to fixed limit curves when the number of cyclic
back-and-forth variations of the control parameter between two consecutive
reversal points is large enough. This convergence to limit curves gives a clear
explanation of the accommodation process. The accommodated minor loops show the
return-point memory property but this property is obviously absent in the case
of non-accommodated minor loops which are not congruent and generally not
closed. In contrast to the traditional Preisach model the reversal point
susceptibilities are non-zero finite values. The stochastic model can provide a
good approximation of the Raylaigh quadratic law when the external parameter
varies between two sufficiently small values.Comment: 13 pages, 14 figure
Poultry compost in the composition of substrates for flower seedlings production
Se evaluaron sustratos formulados con distintas proporciones (20, 50 y 80%) de tres tipos de compost de guano de gallina (CGG1, CGG2, CGG3) mezclados con compost de corteza de pino y un sustrato comercial. Los diez tratamientos fueron usados para el cultivo de plantines de Impatiens walleriana y Salvia splendens. Se caracterizó física y químicamente cada sustrato, y sobre los plantines se evaluó sobrevivencia, masa seca y calcio, magnesio, potasio y sodio en la hoja. Los sustratos con 20% y 50% de los tres CGG tuvieron la mayor capacidad de retención de agua, y con 80%, la mayor porosidad de aire. Los sustratos con 50% y 80% presentaron los más altos valores de pH (≥6,6), potasio y sodio. Para las mismas proporciones, CGG2 y CGG3 presentaron valores de CE >1,1 dS cm-1. La mayor masa seca de los plantines se logró para el sustrato comercial, los sustratos con 20% de los tres CGG y con 50% de CGG1. Estos sustratos exhibieron en las hojas una mayor concentración de calcio y magnesio, y menor de potasio. Las mejores características de sustratos para el desarrollo de los plantines evaluados se lograron en los sustratos con 20% de los tres CGG y con 50% del compost CGG1.Substrates formulated with different proportions (20, 50 and 80%) of three types of poultry compost (CGG1, CGG2, CGG3) mixed with pine bark compost and commercial substrate were evaluated. The ten treatments were used to cultivate seedlings of walleriana Impatiens and Salvia splendens. Each substrate was characterised physically and chemically, and the survival, dry mass and calcium, magnesium, potassium and sodium in the leaf were evaluated in seedlings. Substrates with 20% and 50% among the three CGG presented the highest water retention capacity and, with 80% the highest air porosity. The substrates with 50% and 80% showed the highest values of pH (≥ 6.6), potassium and sodium. For the same proportions, CGG2 and CGG3 presented CE values > 1.1 dS cm-1. The highest dry weight of the seedlings was achieved with the commercial substrate, the substrates with 20% of the three CGG and with 50% of CGG1. These substrates showed a higher concentration of calcium and magnesium, and a lower concentration of potassium in the leaves. The best characteristics of substrates for the development of the seedlings tested were achieved in the substrates with 20% of the three CGG and with 50% of compost CGG1.Fil: Bárbaro, L. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Recursos Naturales. Instituto de Floricultura; ArgentinaFil: Karlanian, M. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Recursos Naturales. Instituto de Floricultura; ArgentinaFil: Rizzo, P. F.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Riera, N. I.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Della Torre, V.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Beltrán, M.. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Recursos Naturales. Instituto de Suelos; ArgentinaFil: Crespo, Diana. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Hysteretic Optimization
We propose a new optimization method based on a demagnetization procedure
well known in magnetism. We show how this procedure can be applied as a general
tool to search for optimal solutions in any system where the configuration
space is endowed with a suitable `distance'. We test the new algorithm on
frustrated magnetic models and the traveling salesman problem. We find that the
new method successfully competes with similar basic algorithms such as
simulated annealing.Comment: 5 pages, 5 figure
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