The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM) model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and ...

In this paper we study the small Na+N (N 12) cationic clusters fragmentation channels, with all electronic calculations performed at the B3LYP/6–311G+(d,p) DFT level of theory. For these cluster sizes, we obtain for all neutral, cationic, bi-cationic and anionic species the optimized geometries, total energies and electronic properties such as the adiabatic ionization potentials, electron affin...

The microstructural features of variable polarity plasma arc welded Al-Cu-Mg 2024-T351 with 2319 filler have been studied by TEM, SEM and DSC. Fusion zone, partial melting zone, resolutionising zone, overageing (for S phase), peak ageing (for S phase) and under ageing zones (for S phase) have been identified. The Ω phase has been observed between re-solutionising zone and peak ageing zone. The ...

J. Jaworski, T. Trzepieciński: Faculty of Mechanical Engineering and Aeronautics, Rzeszow University of Technology, Rzeszów, Poland This paper presents the results of research on the determination of the coefficient of thermal conductivity and hot hardness of cutters made of selected grades of low-alloy high-speed steels, HS 6-5-2 and HS3-1-2. The investigations of hot hardness and yield stress...

This research characterized the effects of water quality and organism age on the toxicity of nickel (Ni) to fathead minnows (Pimephales promelas) to facilitate the accurate development of site-specific water-quality criteria. Nickel sulfate hexahydrate (NiSO4 x 6H2O) was used as the Ni source for performing acute toxicity tests (median lethal concentration after 96-h exposure [96-h LC50]) with ...

the aim of this study was to analyze the impact of green tea on dentin erosion.twelve extracted sound human premolars were immersed in coca cola with a ph of 2.8 for 5 minutes. the surface microhardness was measured with a knoop diamond under a load of 50gr/10s. the teeth were immersed in green tea (camellia sinensis) solution for one minute. the microhardness values were measured again and com...

the aim of this study was to determine the effects of 40% hydrogen peroxide and 15% carbamide peroxide on microhardness and color change of a silorane-based composite resin in comparison with two methacrylate-based composites.fifty-four disc-shaped specimens (a3 shade) were fabricated of filtek p90 (p90), filtek z350xt enamel (z350) and filtek z250 (z250) (3mespe) (n=18). the samples of each co...

this study aimed to assess the effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin.sixty-eight single-rooted single-canal extracted human premolar teeth were used. tooth crowns were separated from the roots at the cementoenamel junction (cej). roots were buccolingually sectioned into mesial and distal halves. specimens were randomly divided into 5 ...

background and aim: marital conflicts are unavoidable in family life, especially between a couple employed in a stressful job such as nursing. therefore, identification and improvement of individualistic skills that can affect marital conflicts are important. the aim of the present study was to evaluate the association between resilience, psychological hardiness, and marital conflicts among nur...