Next-Generation Computational Methods for Enhanced Multiphase Flow Processes - WP2

Next-Generation Computational Methods for Enhanced Multiphase Flow Processes - WP

Heat transfer in drop-laden turbulence

Heat transfer by large deformable drops in a turbulent flow is a complex and rich in physics system, in which drops deformation, breakage and coalescence influence the transport of heat. We study this problem coupling direct numerical simulations (DNS) of turbulence, with a phase-field method for the interface description. Simulations are run at fixed shear Reynolds and Weber numbers. To evaluate the influence of microscopic flow properties, like momentum/thermal diffusivity, on macroscopic flow properties, like mean temperature or heat transfer rates, we consider four different values of the Prandtl number, which is the momentum to thermal diffusivity ratio: Pr=1, Pr=2, Pr=4 and Pr=8. The drops volume fraction is Phi=5.4% for all cases. Drops are initially warmer than the turbulent carrier fluid, and release heat at different rates, depending on the value of Pr, but also on their size and on their own dynamics (topology, breakage, drop-drop interaction). Computing the time behavior of the drops and carrier fluid average temperatures, we clearly show that an increase of Pr slows down the heat transfer process. We explain our results by a simplified phenomenological model: we show that the time behavior of the drops average temperature is self similar, and a universal behavior can be found upon rescaling by t/Pr^2/3

Solution Structure of Cox11, a Novel Type of β-Immunoglobulin-like Fold Involved in CuB Site Formation of Cytochrome c Oxidase

Cytochrome c oxidase assembly process involves many accessory proteins including Cox11, which is a copper-binding protein required for Cu incorporation into the Cu(B) site of cytochrome c oxidase. In a genome wide search, a number of Cox11 homologs are found in all of the eukaryotes with complete genomes and in several Gram-negative bacteria. All of them possess a highly homologous soluble domain and contain an N-terminal fragment that anchors the protein to the membrane. An anchor-free construct of 164 amino acids was obtained from Sinorhizobium meliloti, and the first structure of this class of proteins is reported here. The apoform has an immunoglobulin-like fold with a novel type of beta-strand organization. The copper binding motif composed of two highly conserved cysteines is located on one side of the beta-barrel structure. The apoprotein is monomeric in the presence of dithiothreitol, whereas it dimerizes in the absence of the reductant. When copper(I) binds, NMR and extended x-ray absorption fine structure (EXAFS) data indicate a dimeric protein state with two thiolates bridging two copper(I) ions. The present results advance the knowledge on the poorly understood molecular aspects of cytochrome c oxidase assembly

Determinants of adaptive capacities and coping strategies to climate change related extreme events by forest dependent communities in Malawi

Climate change related extreme events present significant threats against the sustainability of forest-based livelihoods. Adaptive capacities and coping strategies of forest residents in Malawi towards climate change and extreme weather events were analyzed. Purposive sampling was used to select key informants while random sampling was employed to sample household heads or older member of the household (n = 422) involved in the household survey. Questionnaire administration, interviews and focus group discussions were used to collect the primary data. Cross tabulation of frequencies, Pearson Chi-square tests, and Binary logistic regression tests were used for the data analysis. Results showed that forest residents have always employed different adaptation and coping strategies during different climate extreme events over the years. Winter cropping (Dimba) around streams and wells, scored 66 % in Mchinji whilst the shifting of crop planting periods to coincide with rainy seasons topped the list in Mangochi (55 %) against droughts and erratic rainfall, respectively. Household satisfaction with water supply facilities and communication services dictated the respondents’ choice of the coping strategies employed. Furthermore, household human capital enhanced the adaptive capacity of forest residents. In conclusion, institutional services, social networks and human capital resources are important in devising climate coping and adaptation strategies hence recommending for more sustainable and transformative adaptation and coping strategies that can withstand projected climate change and weather-related events.https://www.sciencedirect.com/journal/wellbeing-space-and-societyhj2024Forestry and Agricultural Biotechnology Institute (FABI)SDG-10:Reduces inequalitiesSDG-15:Life on lan

The Role of PIXE and XRF in Heritage Science: The INFN-CHNet LABEC Experience

Analytical techniques play a fundamental role in heritage science. Among them, Particle Induced X-ray Emission (PIXE) and X-ray Fluorescence (XRF) techniques are widely used in many laboratories for elemental composition analysis. Although they are well-established, a strong effort is put on their upgrade, making them suitable for more and more applications. Over the years, at the INFN-LABEC (the laboratory of nuclear techniques for the environment and cultural heritage of the Italian National Institute of Nuclear Physics), the INFN-CHNet group, the network devoted to cultural heritage, has carried out many technological improvements to the PIXE and XRF set-ups for the analysis of works of art and archaeological finds. Among the many, we recall here the scanning external microbeam facility at the TANDEM accelerator and the MA-XRF scanner. The two instruments have shown complementary features: the former permits quantitative analysis of elements heavier than sodium, which is not possible with the latter in most of the case studies. On the contrary, the scanner has the undeniable advantage of portability, allowing it to work in situ. In this framework of technological developments in heritage science, INFN, CERN, and OPD are jointly carrying on the MACHINA (Movable Accelerator for Cultural Heritage In-situ Non-destructive Analysis) project for on-site Ion Beam Analysis (IBA) studies on cultural heritage

"Sepsi da Klebsiella pneumoniae-KPC: esperienza nell'ospedale di Pisa nel biennio 2012-2013"

Klebsiella pneumoniae è un bacillo gram negativo della famiglia Enterobacteriaceae considerato un comune saprofita di uomo e animali, che colonizza il tratto gastrointestinale, cute e nasofaringe oltre a ritrovarsi in varie nicchie ambientali (suolo,acqua..). Dagli anni 70 però l’epidemiologia e lo spettro delle manifestazioni cliniche da Klebsiella pneumoniae è notevolmente cambiato poichè è diventato un germe comune sopratutto in ambito ospedaliero e conseguentemente causa importante di infezioni nosocomiali. Tuttavia a partire dalla fine anni 90’ una nuova classe di enzimi batterici capaci di inattivare anche i carbapenemi, nota come Klebsiella pneumoniae carbapenemasi (KPCs), si è rapidamente diffusa a partire dagli Stati Uniti (1996, North Carolina ) al nordest Usa, Porto Rico e da qui a livello globale con Israele e Grecia attualmente considerate zone endemiche. [2] La diffusione globale di tali CRE in ambito nosocomiale pone notevoli problemi sia di ordine clinico sia per l’impatto in termini di sanità pubblica

Decentralised governance : A case study of forest policy and community based forest management in Lilongwe district Malawi

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Influence of density and viscosity on deformation, breakage, and coalescence of bubbles in turbulence

We investigate the effect of density and viscosity differences on a swarm of large and deformable bubbles dispersed in a turbulent channel flow. For a given shear Reynolds number, Reτ=300, and a constant bubble volume fraction, φ≃5.4%, we perform a campaign of direct numerical simulations of turbulence coupled with a phase-field method accounting for interfacial phenomena. For each simulation, we vary the Weber number (We, ratio of inertial to surface tension forces), the density ratio (ρr, ratio of bubble density to carrier flow density) and the viscosity ratio (ηr, ratio of bubble viscosity to carrier flow viscosity). Specifically, we consider two Weber numbers, We=1.50 and We=3.00, four density ratios, from ρr=1 down to ρr=0.001, and five viscosity ratios, from ηr=0.01 up to ηr=100. Our results show that density differences have a negligible effect on breakage and coalescence phenomena, while a much stronger effect is observed when changing the viscosity of the two phases. Increasing the bubble viscosity with respect to the carrier fluid viscosity damps turbulence fluctuations, makes the bubble more rigid, and strongly prevents large deformations, thus reducing the number of breakage events. Local deformations of the interface, on the contrary, depend on both density and viscosity ratios: as the bubble density is increased, a larger number of small-scale deformations, small dimples and bumps, appear on the interface of the bubble. The opposite effect is observed for increasing bubble viscosities: the interface of the bubbles become smoother. We report that these effects are mostly visible for larger Weber numbers, where surface forces are weaker. Finally, we characterize the flow inside the bubbles; as the bubble density is increased, we observe, as expected, an increase in the turbulent kinetic energy (TKE) inside the bubble, while as the bubble viscosity is increased, we observe a mild reduction of the TKE inside the bubble and a strong suppression of turbulence