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Silvana Di Sabatino

Bio: Silvana Di Sabatino is an academic researcher from University of Bologna. The author has contributed to research in topics: Turbulence & Environmental science. The author has an hindex of 27, co-authored 91 publications receiving 3836 citations. Previous affiliations of Silvana Di Sabatino include University of Notre Dame & University of Salento.


Papers
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Journal ArticleDOI
TL;DR: It is concluded that the reforestation policy, which is introduced to mitigate the greenhouse emissions, causes a further increase in the temperature and livestock heat discomfort.

3 citations

Journal ArticleDOI
TL;DR: In this article, double-nosed low-level jets (LLJ) were found to develop within the planetary boundary layer (PBL) during stable nocturnal conditions and present two possible mechanisms responsible for their formation.
Abstract: In the realm of boundary-layer flows in complex terrain, low-level jets (LLJs) have received considerable attention, although little literature is available for double-nosed LLJs that remain not well understood. To this end, we use the MATERHORN dataset to demonstrate that double-nosed LLJs developing within the planetary boundary layer (PBL) are common during stable nocturnal conditions and present two possible mechanisms responsible for their formation. It is observed that the onset of a double-nosed LLJ is associated with a temporary shape modification of an already-established LLJ. The characteristics of these double-nosed LLJs are described using a refined version of identification criteria proposed in the literature, and their formation is classified in terms of two driving mechanisms. The wind-driven mechanism encompasses cases where the two noses are associated with different air masses flowing one on top of the other. The wave-driven mechanism involves the vertical momentum transport by an inertial-gravity wave to generate the second nose. The wave-driven mechanism is corroborated by the analysis of nocturnal double-nosed LLJs, where inertial-gravity waves are generated close to the ground by a sudden flow perturbation.

3 citations

Book ChapterDOI
03 Dec 2016
TL;DR: In this paper, the authors provide an overview of current understanding of local scale flows and dispersion with attention to the urban canopy layer and related spatial and temporal scales, highlighting key processes at various spatial-temporal scales.
Abstract: This review paper provides an overview of current understanding of local scale flows and dispersion with attention to the urban canopy layer and related spatial and temporal scales. The presence of buildings and topographic features are responsible for a vast number of processes ranging from simple drag and friction effects, wakes, corner vortices, flow separation and reattachment to differential heating leading to local thermal circulation. In highlighting key processes at various spatial-temporal scales, it will be shown lesson learnt from recent laboratory and field experiments. Progress made in understanding physical mechanisms occurring in streets, between groups of buildings and above, has inspired the advance of new conceptual models suitable for operational applications and development of sub-grid parameterizations within “urbanized” mesoscale weather prediction models. Among recent developed conceptual framework the one of city breathability is an example of how integrated knowledge (from physics-based understanding to computational fluid dynamics) can capture salient aspects of ventilation and dispersion in cities. After reviewing the relevant processes, the role of buildings, urban morphology and thermal characteristics are examined in view of delineating future developments and challenges.

2 citations

Journal ArticleDOI
01 Apr 2020
TL;DR: The increasing frequency and severity of hydro-meteorological events on land and sea have a high impact globally as mentioned in this paper, and an increasing number of people is exposed to climate-related hazards each year.
Abstract: The increasing frequency and severity of hydro-meteorological events on land and sea have a high impact globally. Extreme hydro-meteorological events such as hurricanes, intense cyclones, or destructive thunderstorms appear to be associated with climate change and an increasing number of people is exposed to climate-related hazards each year – particularly the most vulnerable. Furthermore, the massive deforestation, over-building of rural and coastal areas, and modification of natural watersheds have made territories more prone to hazards. The science behind these phenomena is complex and multi-disciplinary as the international scientific community explores solutions that not only mitigate the impact of hydrometeorological events but also can contribute to disaster risk reduction and achieve the broader goals of the Sendai Framework, as well as the Sustainable Development Goals of the United Nations. Additionally, advancement in evidence-based knowledge, together with progress in Bulletin of Atmospheric Science and Technology https://doi.org/10.1007/s42865-020-00007-4

2 citations

Journal ArticleDOI
25 May 2021-Energies
TL;DR: In this paper, the complex interaction between inertial and thermal forces within the canyon, including the impacts on turbulent features and pollutant removal mechanisms, was investigated, and numerical analyses allowed a definition of a local Richardson number based on in-canyon quantities only and a new formulation was proposed to characterize the thermo-dynamics regimes.
Abstract: Thermal convective flows are common phenomena in real urban canyons and strongly affect the mechanisms of pollutant removal from the canyon. The present contribution aims at investigating the complex interaction between inertial and thermal forces within the canyon, including the impacts on turbulent features and pollutant removal mechanisms. Large-eddy simulations reproduce infinitely long square canyons having isothermal and differently heated facades. A scalar source on the street mimics the pollutant released by traffic. The presence of heated facades triggers convective flows which generate an interaction region around the canyon-ambient interface, characterised by highly energetic turbulent fluxes and an increase of momentum and mass exchange. The presence of this region of high mixing facilitates the pollutant removal across the interface and decreases the urban canopy drag. The heating-up of upwind facade determines favourable convection that strengthens the primary internal vortex and decreases the pollutant concentration of the whole canyon by 49% compare to the isothermal case. The heating-up of the downwind facade produces adverse convection counteracting the wind-induced motion. Consequently, the primary vortex is less energetic and confined in the upper-canyon area, while a region of almost zero velocity and high pollution concentration (40% more than the isothermal case) appears at the pedestrian level. Finally, numerical analyses allow a definition of a local Richardson number based on in-canyon quantities only and a new formulation is proposed to characterise the thermo-dynamics regimes.

2 citations


Cited by
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01 Jan 1989
TL;DR: In this article, a two-dimensional version of the Pennsylvania State University mesoscale model has been applied to Winter Monsoon Experiment data in order to simulate the diurnally occurring convection observed over the South China Sea.
Abstract: Abstract A two-dimensional version of the Pennsylvania State University mesoscale model has been applied to Winter Monsoon Experiment data in order to simulate the diurnally occurring convection observed over the South China Sea. The domain includes a representation of part of Borneo as well as the sea so that the model can simulate the initiation of convection. Also included in the model are parameterizations of mesoscale ice phase and moisture processes and longwave and shortwave radiation with a diurnal cycle. This allows use of the model to test the relative importance of various heating mechanisms to the stratiform cloud deck, which typically occupies several hundred kilometers of the domain. Frank and Cohen's cumulus parameterization scheme is employed to represent vital unresolved vertical transports in the convective area. The major conclusions are: Ice phase processes are important in determining the level of maximum large-scale heating and vertical motion because there is a strong anvil componen...

3,813 citations

Journal ArticleDOI
TL;DR: This review highlights the research aimed at the implementation of MOFs as an integral part of solid-state microelectronics and discusses the fundamental and applied aspects of this two-pronged approach.
Abstract: Metal-organic frameworks (MOFs) are typically highlighted for their potential application in gas storage, separations and catalysis. In contrast, the unique prospects these porous and crystalline materials offer for application in electronic devices, although actively developed, are often underexposed. This review highlights the research aimed at the implementation of MOFs as an integral part of solid-state microelectronics. Manufacturing these devices will critically depend on the compatibility of MOFs with existing fabrication protocols and predominant standards. Therefore, it is important to focus in parallel on a fundamental understanding of the distinguishing properties of MOFs and eliminating fabrication-related obstacles for integration. The latter implies a shift from the microcrystalline powder synthesis in chemistry labs, towards film deposition and processing in a cleanroom environment. Both the fundamental and applied aspects of this two-pronged approach are discussed. Critical directions for future research are proposed in an updated high-level roadmap to stimulate the next steps towards MOF-based microelectronics within the community.

908 citations

01 Apr 1992
TL;DR: In this paper, the authors proposed a monotone integrated large eddy simulation approach, which incorporates a form of turbulence modeling applicable when the large-scale flows of interest are intrinsically time dependent, thus throwing common statistical models into question.
Abstract: Fluid dynamic turbulence is one of the most challenging computational physics problems because of the extremely wide range of time and space scales involved, the strong nonlinearity of the governing equations, and the many practical and important applications. While most linear fluid instabilities are well understood, the nonlinear interactions among them makes even the relatively simple limit of homogeneous isotropic turbulence difficult to treat physically, mathematically, and computationally. Turbulence is modeled computationally by a two-stage bootstrap process. The first stage, direct numerical simulation, attempts to resolve the relevant physical time and space scales but its application is limited to diffusive flows with a relatively small Reynolds number (Re). Using direct numerical simulation to provide a database, in turn, allows calibration of phenomenological turbulence models for engineering applications. Large eddy simulation incorporates a form of turbulence modeling applicable when the large-scale flows of interest are intrinsically time dependent, thus throwing common statistical models into question. A promising approach to large eddy simulation involves the use of high-resolution monotone computational fluid dynamics algorithms such as flux-corrected transport or the piecewise parabolic method which have intrinsic subgrid turbulence models coupled naturally to the resolved scales in the computed flow. The physical considerations underlying and evidence supporting this monotone integrated large eddy simulation approach are discussed.

849 citations

Journal ArticleDOI
Chun Chen1, Bin Zhao1
TL;DR: In this article, the authors provide an up-to-date revision for both experiment and modeling on relationship between indoor and outdoor particles, using three different parameters: indoor/outdoor (I/O) ratio, infiltration factor and penetration factor.

755 citations

Journal ArticleDOI
TL;DR: In this paper, a review revealed that design and choice of urban vegetation is crucial when using vegetation as an ecosystem service for air quality improvements, while low vegetation close to sources can improve air quality by increasing deposition.

739 citations