Sol-gel titania films were deposited on 316L stainless steel using titanium isopropoxide as a chemical precursor. Dipcoating was performed at withdrawal speeds of 6 mm/min, 30 mm/min, and 60 mm/min. Deposited gel films were heat treated in air at 80 ̊C, 100 ̊C, 300 ̊C, and 400 ̊C. The structural evolution of the coatings was evaluated by infrared reflection-absorption spectroscopy. The influence of...

We systematically studied the physical properties of a novel superhard (t-C₃N₄) and a novel hard (m-C₃N₄) C₃N₄ allotrope. Detailed theoretical studies of the structural properties, elastic properties, density of states, and mechanical properties of these two C₃N₄ phases were carried out using first-principles calculations. The calculated elastic constants and the hardness revealed that t-C₃N₄ i...

Micron-thick boron films have been deposited by Pulsed Laser Deposition in vacuum on several substrates at room temperature. The use of high energy pulses (>700 mJ) results in the deposition of smooth coatings with low oxygen uptake even at base pressures of 10 -4 -10 -3 Pa. A detailed structural analysis, by X-Ray Diffraction and Raman, allowed to assess the amorphous nature of the deposited f...

The main aim of this paper was to determine the amount of Al2O3 reinforcement that results into best combination of strength. Magnesium nano composites containing 3.5, 7.0 and 14 volume percentage of Al2O3 were synthesized through powder metallurgy route. Resistance of furnace sintering technique (heating rate: 49°C/min).Micro structural characterization revealed reasonably uniform distribution...

Metallic miniature products have been highlighted as mini-/micro-structural components working as a precise mechanism, in dispensing systems, and in medical operations. In particular, the essential mechanical parts such as pipes and nozzles have strength and hardness sufficient for ejecting viscous liquids, solders, and particles. A low-temperature plasma nitriding process was proposed as a sur...

In the current work, a novel magnesium alloy Elektron21 reinforced by ceramic AlN nanoparticles were produced by an ultrasound-assisted casting. The fabricated nanocomposites were investigated to evaluate their microstructure, hardness, physical, thermal and electrical conductivity. The microstructural evolutions show that a uniform dispersion of the ceramic particles within the matrix can be a...

This paper studies Upper Domination, i.e., the problem of computing the maximum cardinality of a minimal dominating set in a graph, with a focus on parameterised complexity. Our main results include W[1]-hardness for Upper Domination, contrasting FPT membership for the parameterised dual Co-Upper Domination. The study of structural properties also yields some insight into Upper Total Domination...

We study decision problems of the following form: Given an instance of a combinatorial problem, can it be solved by a greedy algorithm? We present algorithms for the recognition of greedy instances of certain problems, structural characterization of such instances for other problems, and proofs of NP-hardness of the recognition problem for some other cases. Previous results of this type are als...

This paper describes the fabrication and mechanical testing of Al-Mg-boron carbide particulate composites using stir casting technique. The size of the boron carbide particulates is ranging between 30 to 100 μm. The boron carbide contents are varied from 3 and 7% by weight and are dispersed in the alloy matrix. The mechanical properties of the castings, particularly their tensile properties and...

Phosphoric acid added L-alanine (PLA) single crystals were grown successfully by slow evaporation technique at room temperature by taking 2:1 molar ratio of L-alanine and phosphoric acid. Solubility and nucleation kinetic measurements were carried out for the PLA sample. Critical nucleation parameters have been calculated. Structural analysis reveals that PLA crystal crystallizes in orthorhombi...