Given a railway network together with information on the population and their use of the railway infrastructure, we are considering the e ects of introducing new train stops in the existing railway network. One e ect concerns the accessibility of the railway infrastructure to the population, measured in how far people live from their nearest train stop. The second e ect we study is the change i...

In this study, bulk ultrafine-grained and micro-crystalline cobalt was prepared using a combination of high-energy ball milling and subsequent spark plasma sintering. The average grain sizes of the ultrafine-grained and micro-crystalline materials were 200 nm and 1 μm, respectively. Mechanical properties such as the compressive yield strength, the ultimate compressive strength, the maximum comp...

Combinatorial optimization problems form a set of problems which need a considerable effort and time to be solved. Their difficulty lies in the fact that there is no formula for solving them exactly. Every possibility has to be examined in order to find the best solution and the number of possibilities increases exponentially as the size of the problem increases. In this paper we discussed abou...

The present study evaluates the effect of a substrate’s silicon content on coatings’ morphology, structure, and properties in an electrolyte containing sodium tungstate Al–xSi alloys. PEO-coated samples demonstrated structure pancake crater with irregular micro-cracks micro-pores. incorporation element W coatings decreased surface roughness porosity due to increasing conductivity and, hence, de...

We use exact enumeration to characterize the solutions of quadratic unconstrained binary optimization problems less than 21 variables in terms their distributions Hamming distances close-by solutions. also perform experiments with D-Wave Advantage 5.1 quantum annealer, solving many instances up 170-variable, problems. Our results demonstrate that exponents characterizing success probability a a...

In this paper we propose a mathematical programming model for a large drinking water supply network and discuss some possible extensions. The proposed optimization model is of a real water distribution network, the largest water supply network in Flanders. The problem is nonlinear, nonconvex and involves some binary variables, making it belong to the class of NP-hard problems. We discuss a way ...

Various types of hydroxyapatite (HA) structures have received great attention of scientific researcher in biomaterials field. Also, it is common that HA is the essential inorganic materials in human hard tissue such as bone or teeth. Fracture toughness and micro-hardness properties are the important parameters required for the prediction of the mechanical performance of biomaterials structures ...

BACKGROUND The aim of the present study was to test the impact of different toothpastes with Zinc-Hydroxyapatite (Zn-HAP) on preventing and repairing enamel erosion compared to toothpastes with and without fluoride. MATERIAL AND METHODS The following four toothpastes were tested: two toothpastes with Zn-HAP, one toothpaste with fluoride and one toothpaste without fluoride. An additional contr...