Through a systematic structural search we found an allotrope of carbon with Cmmm symmetry which we predict to be more stable than graphite for pressures above 10 GPa. This material, which we refer to as Z-carbon, is formed by pure sp(3) bonds and it provides an explanation to several features in experimental x-ray diffraction and Raman spectra of graphite under pressure. The transition from gra...

Point clouds data, obtained from RGB-D cameras and laser scanners, or constructed through structural from motion (SfM), are becoming increasingly popular in the field of robotics perception. To allow efficient robot interaction, we require not only the local appearance and geometry, but also a higher level understanding of the scene. Such semantic representation is also necessary for as-built B...

Question: Do the biomechanical properties of the diet influence the tooth shape of insectivores? We examined dietary ‘intractability’, the extent to which structural strength, toughness and stiffness of a food are increased, roughly equivalent to ‘hardness’. Hypotheses: The following three factors may cause discrepancies in tooth form in animals with different diets: (1) optional functional for...

Temperature, salt and water contents are key processing factors in dry-cured ham production. They affect how proteolysis, lipid oxidation, structure and texture evolve, and thus determine the sensory properties and final quality of dry-cured ham. The aim of this study was to quantify the interrelationships and the time course of (i) proteolysis, (ii) lipid oxidation, (iii) five textural paramet...

With incredible hardness and excellent wear-resistance, nanocrystalline diamond (NCD) coatings are gaining interest in the biomedical community as articulating surfaces of structural implant devices. The focus of this study was to deposit multilayered diamond coatings of alternating NCD and microcrystalline diamond (MCD) layers on Ti-6Al-4V alloy surfaces using microwave plasma chemical vapor d...

The role of sandwich Cu layer in and effect of self-bias on structural and nanomechanical properties of Cu/DLC bilayer films have been explored. Cu/DLC bilayer filmswere grown, under varied self-bias from−125 to−225V, using hybrid system involving radiofrequency(RF-) plasma-enhanced chemical vapor deposition and RF-sputtering units. Surface topography and mean roughness was studied by atomic fo...

The complexity of various Constraint Satisfaction Problems (CSP) when parameterized by structural measures (such as treewidth or clique-width) is a very well-investigated area. In this paper, we take a fresh look at such questions from the point of view of approximation, considering four standard CSP predicates: AND, OR, PARITY, and MAJORITY. By providing new or tighter hardness results for the...

Nanomechanical properties of indium nanowires like structures fabricated on quartz substrate by trench template technique, measured using nanoindentation. The hardness and elastic modulus of wires were measured and compared with the values of indium thin film. Displacement burst observed while indenting the nanowire. 'Wire-only hardness' obtained using Korsunsky model from composite hardness. N...

This lecture is about hardness and computational problems that seem hard. Almost all of the theory of hardness is based on assumptions. We make assumptions about some problems, then we do reductions from one problem to another. Then, we want to make the minimal number of assumptions necessary to show computational hardness. In fact, all work on computational complexity and hardness is essential...

We provide counter–examples to Mulmuley’s SH conjecture for the Kronecker coefficients. This conjecture was proposed in the setting of Geometric Complexity Theory to show that deciding whether or not a Kronecker coefficient is zero can be done in polynomial time. We also provide a short proof of the #P–hardness of computing the Kronecker coefficients. Both results rely on the connections betwee...