In this study, the microstructural evolutions, formed phases, micro-and macro-hardness changes and shear properties were evaluated in the as-cast, homogenized, cold-rolled and annealed AlCoCrFeNi2. 1 eutectic high-entropy alloy (EHEA). These studies were carried out using X-ray fluorescence (XRF), scanning electron microscopy (SEM), Rockwell C and Vickers hardness testing as well as shear punch testing (SPT). The microstructure after cold rolling followed by annealing was consisted of an elongated phases/grains in the direction of cold rolling and in almost equiaxed phases/grains. The homogenized specimen has the minimum amounts of hardness and yield/ultimate shear strength. Due to the presence of both elongated and equiaxed structures in the cold-rolled and annealed sample, the hardness and yield/ultimate shear strength of this specimen is between that of as-cast and homogenized cases.

Eutectic Silicon phases form as the coarse and acicular shape in Aluminum-Silicon alloys.These phases have detrimental effect on mechanical properties of casting parts. Modification process has been used to change the shape of these phases to fibrous morphology. In this research different level of strontium; in the form of Al-10%Srmaster alloy; have been added to 319 aluminum alloy to investigate their effects on modification. Thermal Analysis has been used as a technique to study the cooling curves and first derivative curves. Effect of strontium on solidification parameters such as nucleation temperature (TN,si), and growth temperature (TG,Si) of eutectic silicon has been determined. (TN,si)and (TG,Si) have been reduced by increasing strontium content. (DTEGAl-Si) can be used as a parameter to control the modification of eutectic silicon. The results of this research indicate that thermal analysis technique can be used as an accurate and quick device of on-line quality control in production lines of aluminum casting industries.

The properties of cast parts are influenced by their microscopic and macroscopic structures. Any changes in the structure during the solidification process can cause inhomogeneity in the properties of the casting. Among these changes, It can be pointed out the transition from columnar to equiaxed structures.This research study investigated the impact of superheat temperature and modification treatment on the transition from columnar to equiaxed growth in directionally solidified aluminum-silicon eutectic alloy. In a directional solidification system, the molten alloy was cooled from varying temperatures (590, 630, 660, and 730 oC) to room temperature. Temperature measurements were taken from six points at a certain distance from the cooling surface in order to estimate the cooling rate and calculate the temperature gradient and growth rate. The macroscopic and microscopic structures were evaluated to determine the transition zone from columnar to equiaxed grains and the change in eutectic growth morphology. The results of the study indicate that the transition from columnar to equiaxed growth occurs at a cooling rate lower than 0.13 K/s. Moreover, it was found that modifying the structure of silicon with adding 0.05 wt.% of strontiuminto the melt causes the transition from columnar to equiaxed growth to occur at a cooling rate of 0.21 K/s.

Background: The European Higher Education Area (EHEA) has aimed at unifying, harmonizing, and ensuring consistency of higher education systems in Europe for over two decades. The objective of this study was to investigate the similarities and differences in the training programs of nurses in selected EHEA member countries. Methods: Comparative analysis was used. Based on three sources: research articles, internet databases, and emails sent to nursing education institutions. Three databases, namely Science Direct, PubMed, and ERIC, were utilized. Results: Regarding educational institutions, the majority of countries' nurses graduated with a Bachelor's degree, except for Estonia, Russia, and North Macedonia. Russia had the shortest education duration (2 years and 10 months), while other member countries had programs lasting between 3-4 years. In countries where colleges were still active, diploma or certificate programs were offered, such as in Estonia and Russia. Only North Macedonia did not offer any continuing education for nurses, and Estonia, Latvia, and France did not have PhD programs in nursing. Conclusion: Nurses constitute the largest occupational group in healthcare, and the quality of medical care relies on their theoretical and practical training. Despite efforts to unify nursing curricula through the Bologna Process, significant differences still exist.

Introduction In 2003 Abbott et al. reported a new generation of ionic liquid (IL) entitled deep eutectic solvents (DESs), a new class of solvents. DESs have two or three components with a large depression of melting points [1]. These ingredients involve a variety of ionic and neutral species and have the role of either hydrogen bond acceptors or hydrogen bond donors, which play the role of Lewis or Bronsted acids and bases [2]. Recyclability, low vapor pressure, and low toxicity are important properties of deep eutectic solvents. These Eco-friendly properties of deep eutectic solvents have attracted researchers' attention [2, 3]. Bio-oil and biofuel productions [4-7],...

In this research, the effect of the hot-pressing process on the microstructure and hardness of A390 cast aluminum-silicon alloy was investigated. The results were prepared using an optical microscope and hardness tester. The microstructure of the casting sample included very coarse primary silicones, acicular eutectic silicones, intermetallic compounds, and large alpha-phase dendrites. By increasing the amount of strain in the hot-pressing process, primary and eutectic silicones as well as intermetallic compounds were broken and finer, and their distribution in the alpha matrix became more uniform. The obtained results showed that the microstructure of the casting alloy has been improved in terms of the modification of primary silicon particles, eutectic silicon, and intermetallic compounds, as well as the uniform distribution of these particles and the removal of porosity. The initial silicon size is dramatically reduced from over 100 µm (for the cast sample) to less than 5 µm (after the seventh pass). By increasing the strain up to the fourth pass, the hardness of the alloy decreased from 87 to 65 HB. With the further increase of the strain from the fourth pass to the seventh (final) pass, the hardness value increased to 81 HB.

In the present study, solidification process of Al-Fe eutectic alloys at a metallic mold was done by finite difference method; and the hot tearing sensitivity was investigated. The mold was designed for directional solidification toward the mold center. The results of simulation revealed that the solidification was done in two stages. In the first stage, the mushy zone thickness was increased and in the second stage it was decreased. As the Fe content was increased, the time of first stage was decreased while the time of second one was independent of Fe amounts. In this work, it was supposed that the hot tear is formed only in a pero-eutectic continuous solid network, so, a criterion for hot tearing susceptibility was introduced based on the mushy zone thickness and local solidification time. In this criterion, the hot tears filled with eutectic melt were account as healed hot tears. The results depicted that all alloys could be sensitive to hot tearing during first stage. Because of low cooling rate during the second stage, the melt experiences near equilibrium solidification; therefore the pero-eutectic solid network could not be formed in Al-1. 5wt% alloy and consequently this alloy was not sensitive to hot tear. The most sensitivity was related to Al-1wt%Fe and Al-1. 5wt%Fe alloys. At the second stage of solidification, the most sensitivity was related to Al-1wt%Fe alloy.

In the present research, different trends of temperature of eutectic ending and duration of eutectic transformation due to employment of different combinations of five types of inoculants and four types of modularizes, with different fading resistances, were studied. Cooling curves and image analysis were used to characterize the influence of holding time, for 0, 5, 10, 15 and 20 min, on the samples prepared from the melt processed by 2.5 wt% modularize and 0.4 wt% inoculants and kept at 1320ºC under nitrogen atmosphere. Chemical composition of 20 samples out of 100 attained by the means of emission spectrometry. While the dominant graphite morphology is spherical or flake, by succeeding of the fading phenomenon, temperature of eutectic ending and duration of eutectic transformation respectively decrease, increase and decrease again. When there is a combination of spherical, compacted and flake graphite, the above results are reverse. As long as the main graphite morphology is spherical, Mg, S and Al content decrease by advancement of fading, nevertheless after this stage, Mg and Al content reach a steady state whereas S content slightly increases.