BIPI

Abstract.The main purpose of heat transfer fluids is to transport heat energy between two media, with the best possible efficiency, the lowest possible energy losses, in an optimal time with an improved system performance. It is known that the addition of nanoparticles to a base fluid considerably improves its heat transfer properties and polyethylene glycol (PEG) based nanofluids are a new class of heat transfer fluids obtained by dispersing different kinds of nanoparticles (carbon nanotubes, graphene, magnesium oxide, zinc oxide, copper, alumina, etc.) in a liquid polyethylene glycol (PEG), having a low molecular weight. PEG is a chemical compound with relatively low viscosity, which is thermally and chemically stable, non-corrosive, non-toxic, being an ideal medium for developing heat transfer fluids. In the case of nanofluids, a series of thermal, physical and rheological properties are monitored and this paper presents a brief analysis of some experimental results on thermal diffusivity, an essential property for the characterization of nanofluids for heat transfer.
Keywords: nanofluid, nanoparticles, heat transfer, polyethylene glycol, nanofluids.
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Abstract. Ceramic coatings with thermal barrier function (TBC) are widely used in extreme thermal environments, such as gas turbines, aero-engines and automotive high-performance systems, where metallic components require protection against oxidation and overheating. This paper reviews the main deposition techniques of thermal barrier coatings, with emphasis on atmospheric plasma spray (APS), vacuum plasma spray (VPS), low-pressure plasma spray (LPPS), and electron beam physical vapor deposition (EB-PVD). The microstructural characteristics, porosity, adhesion mechanisms and functional behavior of yttria-stabilized zirconia (YSZ) layers are analyzed in correlation with their deposition method. Moreover, the role of bond coats (MCrAlY alloys and NiAl) and thermally grown oxides (TGO) is highlighted as crit ical for durability under cyclic thermal loading. Applications in aerospace, energy and automotive fields are discussed, along with emerging plasma spray techniques such as Suspension Plasma Spray (SPS), which offer potential improvements in thermal insulation and lifetime extension. The study emphasizes the relationship between processing parameters, structural features and the performance of TBCs in service conditions.
Keywords: thermal barrier coatings; atmospheric plasma spray; vacuum plasma spray; low-pressure plasma spray; suspension plasma spray; yttria-stabilized zirconia.
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Abstract.This paper presents a bibliographic analysis of human resource management focused on improving personnel quality. It addresses three questions: whether personnel quality is a managerial issue, how human resource quality can be improved, and how personnel policies influence the quality of the educational process. The analysis supports the view that human resource management is a scientific field requiring integrated personnel policies aligned with organizational strategy. Such alignment contributes to improved work processes, increased employee commitment, higher performance, and greater organizational efficiency.
Education and educational management remain interdisciplinary research areas shaped by organizational and social change. Key contributions in personnel management and educational leadership are provided by authors such as Filippo, Boxall and Purcell, Farnham, Storey, Wright and McMahan, Keenoy, and Armstrong. Studies by Hoy, Bayne-Jardine, and Wood emphasize that staff professionalism is a central organizational indicator, directly influencing parents’and students’ trust in school management. Effective organizational change must recognize human diversity within institutions (Walker et al., 2007). The paper highlights the social importance of educational quality and human resources, echoing John Gray’s view that human potential can always be improved.
Keywords: quality, human resource, management, research, studies.
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Abstract.The aim of this research is the analysis of the decision-making process and its autonomy. As an integral part of the functional mechanisms of an organization, decision-making is a natural act of individuals, especially of managers. Experts have concluded that the act of generating a decision is the bearer of a strategy in which decision-making autonomy holds an important place. Highlighting the values of this managerial attribute involves providing answers related to a relevant segment of our research questions: 1) Within what managerial parameters can a new conceptual determination of decision-making be framed?; 2) To what extent could the model influence the course of the decision-making process, understood as a regulatory mechanism, and the stages of decision formulation?; 3) In what context is the relationship between decision ethics and decision-making autonomy highlighted? The answers lead to the formulation of pertinent conclusions that will contribute to the theoretical and scientific foundation of the research for the development of the doctoral thesis.
Keywords: management, decision, de-concentration, decision-making autonomy.
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Abstract.This study investigates the influence of nucleobase functionalization‒adenine and thymine‒on the photo-induced mass transport behavior, surface-relief grating (SRG) formation, and long-term stability of azobenzene-containing polysiloxane films. Linear azopolysiloxanes with comparable azo-chromophore content but different nucleobase substitution degrees were synthesized and evaluated under identical optical-patterning conditions. The results show that both nucleobase type and substitution degree strongly influence polymer mobility. At comparable substitution levels, adenine-modified films exhibit higher mass-transport efficiency and stronger diffraction intensities. In contrast, thymine-functionalized materials show reduced surface modulation but improved stability, which is attributed to stronger hydrogenbonding interactions. Film thickness also plays a critical role. Thicker layers enhance SRG amplitude in adenine and highly thymine-rich systems, whereas mobility remains limited in films with low thymine content. Overall, the study highlights a clear trade-off between mobility and stability: adenine enhances modulation and transport efficiency, whereas thymine improves long-term structural stability. These findings provide valuable design guidelines for nucleobase-modified azopolysiloxanes tailored for efficient surface patterning or durable nanostructured surfaces, offering design guidelines for robust, lightresponsive polymer systems with tunable nanostructuring.
Keywords: azopolysiloxanes, nucleobase-modified polymers, surfacerelief gratings, mass transport, photoinduced nanostructuring
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