scholarly journals Deforming a Convex Hypersurface with Low Entropy by Its Gauss Curvature

2016 ◽  
Vol 27 (2) ◽  
pp. 1286-1294
Author(s):  
Mohammad N. Ivaki
Author(s):  
S.D. Smith ◽  
R.J. Spontak ◽  
D.H. Melik ◽  
S.M. Buehler ◽  
K.M. Kerr ◽  
...  

When blended together, homopolymers A and B will normally macrophase-separate into relatively large (≫1 μm) A-rich and B-rich phases, between which exists poor interfacial adhesion, due to a low entropy of mixing. The size scale of phase separation in such a blend can be reduced, and the extent of interfacial A-B contact and entanglement enhanced, via addition of an emulsifying agent such as an AB diblock copolymer. Diblock copolymers consist of a long sequence of A monomers covalently bonded to a long sequence of B monomers. These materials are surface-active and decrease interfacial tension between immiscible phases much in the same way as do small-molecule surfactants. Previous studies have clearly demonstrated the utility of block copolymers in compatibilizing homopolymer blends and enhancing blend properties such as fracture toughness. It is now recognized that optimization of emulsified ternary blends relies upon design considerations such as sufficient block penetration into a macrophase (to avoid block slip) and prevention of a copolymer multilayer at the A-B interface (to avoid intralayer failure).


2021 ◽  
Vol 13 (5) ◽  
pp. 2765
Author(s):  
Maria Cerreta ◽  
Gaia Daldanise ◽  
Eleonora Giovene di Girasole ◽  
Carmelo Maria Torre

According to the current European and Italian scenario related to urban regeneration, cultural and landscape heritage valorization is being enhanced by the activation of innovative processes and new emerging approaches. These involve the development of methodologies and tools that can address decision-making processes based on creative practices consistent with a concept named “low-entropy economy” in this paper. The low-entropy economy represents an economic approach based on the minimization of physical urban transformation and the enhancement of the existing heritage. In this perspective, the research aims to develop the Cultural Heritage Low Entropy Enhancement (CHLEE) approach by exploring how some frugal experiences have promoted cultural heritage enhancement and related complex values through a program of temporary uses and activities able to produce new values, where the human experience is essential. A crucial role is represented by the heterogeneity of creative practices that contribute to identifying and implementing innovative management and governance models. The analysis of creative practices, based upon the ex post evaluation of some Italian case studies across the PROMETHEE-GAIA multicriteria method, is able to show how these experiences build innovation ecosystems and improve the ex ante evaluation for new strategies and policies, underlining strengths, weaknesses, and milestones that shape creative experiences as drivers of urban competitiveness.


2020 ◽  
Vol 15 ◽  
pp. 3694-3708
Author(s):  
Jingdian Ming ◽  
Yongbin Zhou ◽  
Wei Cheng ◽  
Huizhong Li ◽  
Guang Yang ◽  
...  
Keyword(s):  

Author(s):  
Muhammad Awais Azam ◽  
Jonathan Loo ◽  
Aboubaker Lasebae ◽  
Sardar Kashif Ashraf Khan ◽  
Waleed Ejaz
Keyword(s):  

2021 ◽  
Author(s):  
David Dellong ◽  
Florent Le Courtois ◽  
Jean-Michel Boutonnier ◽  
Bazile G. Kinda

<p>Maps of underwater noise generated by shipping activity became a useful tool to support international regulations on marine environments. They are used to infer the risk of impact on biodiversity. Maps are performed by 1) computing the emitted noise levels from ships, 2) propagating the acoustic signal in the environment and 3) using localized measurements to validate the results. Because of mismatches in environmental data and a limited number of measurements, noise maps remain highly uncertain.</p><p>In this work, the uncertainty of the noise maps is investigated through the potential complexity of soundscape. The acoustic signal at each receiving cell is computed from the convolution of the source of the ships by the transmission losses of the environment. Complexity is mapped by computing Shannon's entropy of the transmission losses for each receiver. High entropy areas only reflect high shipping densities and favorable acoustic propagation properties of the local environment. Low entropy areas reflect: low shipping density and/or poor acoustic propagation properties. An area with high shipping densities and poor acoustic propagation properties will still have low entropy values.</p><p>Entropy maps allow classifying areas depending on their environmental features. Thus, scenarios of uncertainty are defined. Results highlight the necessity to consider the diversity of the environmental properties in support of the production of noise maps. The methodology could help in optimizing spatial and temporal resolution of map computations, as well as optimizing acoustic monitoring strategies.</p>


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