Homeostatic generative design process: Emergence of the adaptive architectural form and skin to excessive solar radiation

Natural organisms through their evolutionary developments, acquire adaptive morphological and behavioural characteristics within their environmental contexts. Through homeostatic behaviours, organisms, individually and collectively, will sustain internal and external equilibrium in face of environmental fluctuations. There is a wide range of morphological and behavioural traits across multiple species that are rooted in their homeostatic mechanisms throughout their lives. This paper presents an evolutionary design workflow with embedded homeostatic principles to generate a building cluster that is adapted to the contexts with extreme solar radiation

Interacting Spinors-Scalars and AdS/CFT Correspondence

By taking the interacting spinor-scalar theory on the $AdS_{d+1}$ space we calculate the boundary CFT correlation functions using AdS/CFT correspondence.Comment: The crucial role of the surface term in the action to generate the correlation functions quadratic in spinors is considered. LaTeX file, 8 page

Interactions of hydrogen with amorphous hafnium oxide

We used density functional theory (DFT) calculations to study the interaction of hydrogen with amorphous hafnia ( a − HfO 2 ) using a hybrid exchange-correlation functional. Injection of atomic hydrogen, its diffusion towards electrodes, and ionization can be seen as key processes underlying charge instability of high-permittivity amorphous hafnia layers in many applications. Hydrogen in many wide band gap crystalline oxides exhibits negative-U behavior (+1 and − 1 charged states are thermodynamically more stable than the neutral state) . Our results show that in a − HfO 2 hydrogen is also negative-U, with charged states being the most thermodynamically stable at all Fermi level positions. However, metastable atomic hydrogen can share an electron with intrinsic electron trapping precursor sites [Phys. Rev. B 94, 020103 (2016).] forming a [ e − t r + O – H ] center, which is lower in energy on average by about 0.2 eV. These electron trapping sites can affect both the dynamics and thermodynamics of the interaction of hydrogen with a − HfO 2 and the electrical behavior of amorphous hafnia films in CMOS devices

Deep electron and hole polarons and bipolarons in amorphous oxide

Amorphous (a)-HfO2 is a prototype high dielectric constant insulator with wide technological applications. Using ab initio calculations we show that excess electrons and holes can trap in a-HfO2 in energetically much deeper polaron states than in the crystalline monoclinic phase. The electrons and holes localize at precursor sites, such as elongated Hf-O bonds or undercoordinated Hf and O atoms, and the polaronic relaxation is amplified by the local disorder of amorphous network. Single electron polarons produce states in the gap at ∼2 eV below the bottom of the conduction band with average trapping energies of 1.0 eV. Two electrons can form even deeper bipolaron states on the same site. Holes are typically localized on undercoordinated O ions with average trapping energies of 1.4 eV. These results advance our general understanding of charge trapping in amorphous oxides by demonstrating that deep polaron states are inherent and do not require any bond rupture to form precursor sites