355 research outputs found
Emergence of rheological properties in lattice Boltzmann simulations of gyroid mesophases
We use a lattice Boltzmann (LB) kinetic scheme for modelling amphiphilic
fluids that correctly predicts rheological effects in flow. No macroscopic
parameters are included in the model. Instead, three-dimensional hydrodynamic
and rheological effects are emergent from the underlying particulate
conservation laws and interactions. We report evidence of shear thinning and
viscoelastic flow for a self-assembled gyroid mesophase. This purely kinetic
approach is of general importance for the modelling and simulation of complex
fluid flows in situations when rheological properties cannot be predicted {\em
a priori}.Comment: 7 pages, 5 figure
Climate change adaptation and vulnerability assessment of water resources systems in developing countries: a generalized framework and a feasibility study in Bangladesh
Water is the primary medium through which climate change influences the Earth’s ecosystems and therefore people’s livelihoods and wellbeing. Besides climatic change, current demographic trends, economic development and related land use changes have direct impact on increasing demand for freshwater resources. Taken together, the net effect of these supply and demand changes is affecting the vulnerability of water resources. The concept of ‘vulnerability’ is not straightforward as there is no universally accepted approach for assessing vulnerability. In this study, we review the evolution of approaches to vulnerability assessment related to water resources. From the current practices, we identify research gaps, and approaches to overcome these gaps a generalized assessment framework is developed. A feasibility study is then presented in the context of the Lower Brahmaputra River Basin (LBRB). The results of the feasibility study identify the current main constraints (e.g., lack of institutional coordination) and opportunities (e.g., adaptation) of LBRB. The results of this study can be helpful for innovative research and management initiatives and the described framework can be widely used as a guideline for the vulnerability assessment of water resources systems, particularly in developing countries
Rheological properties of binary and ternary amphiphilic fluid mixtures
Within this project, we perform lattice Boltzmann simulations of spinodal decomposition and structuring effects in binary immiscible and ternary amphiphilic fluid mixtures under shear. We use a highly scalable parallel Fortran 90 code for the implementation of the lattice Boltzmann method. We demonstrate that the domain growth mechanisms in ternary amphiphilic fluid mixtures strongly depend on the amphiphile concentration. For systems under constant and oscillatory shear we analyze domain growth rates in directions parallel and perpendicular to the applied shear and find that these systems undergo structural transitions with tubular and lamellar structures appearing
Who is connected with whom? A Social network analysis of institutional interactions in the European CCA and DRR landscape
Communication and collaboration are critical for designing and implementing responses to climate change impacts and related disasters. This acknowledgement has increased interest in understanding social and institutional networks for climate change adaptation (CCA) and disaster risk reduction (DRR). In this study, we used Social Network Analysis (SNA) to explore institutional interactions within and across the communities of the aforementioned domains in Europe. Firstly, we investigated the type and intensity of interactions. We calculated SNA metrics to assess the roles of different actors and applied cluster analysis to identify actors with similar patterns of connections. SNA showed that communication is often more intensive within the two communities, while collaboration is frequent around topics related to both CCA and DRR. Cluster analysis revealed that actors tied with DRR were more closely connected, while actors tied with CCA and those with mixed connections showed no obvious clustering affnity. The European Climate Adaptation Platform, Climate-ADAPT, had the highest value for various SNA metrics, reflecting its popularity in the network and its potential for enhancing interactions among its actors. Finally, SNA was complemented by qualitative interviews, which emphasised the importance of connecting CCA and DRR in organisational mission and vision statements
Effectiveness of Different Analytical Methods for the Characterization of Propolis : a Case of Study in Northern Italy
Propolis is used as folk medicine due to its spectrum of alleged biological and pharmaceutical properties and it is a complex matrix not still totally characterized. Two batches of propolis coming from two different environments (plains of Po Valley and the hilly Ligurian\u2013 Piedmont Apennines) of Northern Italy were characterized using different analytical methods: Spectrophotometric analysis of phenols, flavones and flavonols, and DPPH radical scavenging activity, HPLC, NMR, HSPME and GC\u2013MS and HPLC\u2013MS Orbitrap. Balsam and moisture content were also considered. No statistical differences were found at the spectrophotometric analysis; balsam content did not vary significantly. The most interesting findings were in the VOCs composition, with the Po Valley samples containing compounds of the resins from leaf buds of Populus nigra L. The hills (Appennines) samples were indeed characterize by the presence of phenolic glycerides already found in mountain environments. HPLC\u2013Q-Exactive-Orbitrap\uae\u2013MS analysis is crucial in appropriate recognition of evaluate number of metabolites, but also NMR itself could give more detailed information especially when isomeric compounds should be identified. It is necessary a standardized evaluation to protect and valorize this production and more research on propolis characterization using different analytical techniques
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