This experimental study explores the impact of Magnetic Activation of Water (MAW) on the fresh and hardened properties of Reused Crumb-Rubber Mortar (RCRM). Eight different mortar formulations were produced, comprising four variants using potable water (DW) and four utilizing MAW, with varying percentages of Reused Crumb Rubber Sand (RCRS) substituted for natural sand at rates of 0%, 4%, 8%, and 12%. The analyses of fresh properties indicated that MAW effectively reduced entrapped air and improved the consistency of the RCRM mixtures. In terms of hardened properties, MAW demonstrated a significant enhancement in compressive strength and hydration kinetics of RCRM compared to those made with DW. This innovative approach of employing magnetic activation not only addresses compatibility and heterogeneity challenges typically associated with rubber-cement mixtures but also offers a viable solution for incorporating waste rubber into cement composites. Ultimately, this research presents a promising avenue for improving the mechanical and physical characteristics of recycled materials in sustainable construction practices.

Résumé\nLa création de prairies avec la participation d\'espèces d\'origine locale, adaptées aux conditions climatiques de la région et avec une productivité accrue et une stabilité de rendement est une condition importante pour assurer une production alimentaire durable ou biologique. Dans le but d\'évaluer écologiquement les espèces de prairies dans les régions semi-montagneuses au milieu de Stara Planina en fonction d\'indicateurs et de paramètres liés à la productivité et à la stabilité, une expérimentation a été réalisée pendant la période 2011-2019. Les sujets d\'étude sont les graminées céréalières typiques de la région, dans la variance suivante : fétuque rouge (Festuca rubra L.), ray-grass de pâturage (Lolium perenne L.), tête de hérisson (Dactilis glomerata L.), ray-grass français (Arrhenatherum elatius PB), fétuque roseau (Festuca arundinacea Schreb.), larme (Briza maxima L.), avoine dorée (Trisetum flavescens L.), prairie blanche (Agrostis alba L.). L\'expérience a été réalisée par la méthode des blocs, et les méthodes de régression, de variance et d\'analyse non paramétrique ont été utilisées pour évaluer la stabilité. Selon les valeurs de la plupart des paramètres de stabilité calculés (bi, Si2, λi, σ2i, PP, W2, S⁽³⁾, S⁽⁶⁾, NP⁽¹⁾) la tête de hérisson montre une bonne stabilité écologique. Des appréciations positives peuvent également être attribuées aux espèces à faible rendement de ray-grass de pâturage (bi = 0,30, 16,6 t/ha) et de larme (bi = 0,54, 17,60 t/ha). La fétuque roseau (bi = 1,62 ; 21,00 t/ha) et la fétuque rouge (bi = 1,17 ; 19,90 t/ha) sont instables, mais avec un rendement élevé en masse fraîche. Une évaluation complexe par analyse biplot GGE identifie la fétuque rouge comme une espèce qui combine favorablement une productivité élevée avec une stabilité relative. La tête de hérisson et le ray-grass français se caractérisent par une grande stabilité et un rendement proche de la moyenne du groupe. Ces espèces sont adaptées à la croissance dans un large éventail de conditions environnementales.

The main aim of this research is to understand what motivated academic entrepreneurs to launch business ideas as a firm. The population in this research was chosen using the definition of academic company or Spin-off. To do this, the reasons that motivated 44 academic entrepreneurs at three Costa Rican public universities were analyzed. The results showed that there is no single motivating element when initiating a business Project. This research can be useful for researchers and agents involved in the elaboration of successful public policies for academic entrepreneurship. The main value of this work consists in Absence of research works related to academic entrepreneurship in the universities of Costa Rica. These types of companies, as a result of their scientific base, become key elements in the improvement of the innovative capacity of a territory and the effect on the rest of society. As research limitation is that in Costa Rica the number of academic entrepreneurs and spin-offs is still small. This does not allow to have a wide sample of study.

An experiment in pots was carried out on Medicago sativa L. in order to evaluate the short-term effects of compost based on organic olive tree by-products (Ramial Chipped Wood (RCW), Olive Mill Waste Water (OMW)) on ecosystem services of a sandy soil sampled from an experimental olive orchard in southern Tunisia. Two treatments (RCW and RCW with OMW) were applied and compared to a control soil.\nRCW was the most effective treatment for improving soil phosphorus properties and above-ground biomass. The highest nitrogen content is recorded with the composite compost (RCW and OMW) (0.26 g.kg-1). The Electric Conductivity of treated soil decreased by 60% over time. The RCW compost and the RCW combined with OMW allowed to keep almost the same soil moisture (141.10 and 147.23 g.kg-1, respectively) but almost 3 times more compared to a control soil (52.30 g.kg-1).

The present research studies the effect of the refugee student factor on the burnout and occupational commitment of classroom teachers. The research was conducted within the framework of the relational scanning model. The data were collected from a total of 433 classroom teachers who do and do not have refugee students in their classes and serve in Osmaniye province in Turkey. The “Maslach Burnout Inventory” and “Occupational Commitment Scale” were used as data collection tools. According to the MANOVA test results, the linear combinations of the emotional exhaustion, depersonalization, personal accomplishment sub-dimensions, and occupational commitment of teachers differ significantly depending on whether or not refugee students are in their classes. According to the one-way ANOVA test results, there was no change in their occupational commitment while all sub-dimensions of teachers\' burnout varied somewhat by the refugee student factor. These findings present the effect of refugee students on classroom teachers\' burnout and occupational commitment.

Formation of single-crystal opal films from a suspension of monodisperse spherical silica particles in a dynamic meniscus area is treated as nanocrystallization involving interparticle interaction forces. Preparation of high-quality photonic crystal films with a reflection coefficient in the photonic band gap up to 95% is based on the concept of equilibrium crystallization. Two- and three-layer heterostructures have been produced from single-crystal films with various sizes of silica spheres. Well-resolved allowed ranges within photonic band gaps have been detected for three-layer heterostructures, suggesting interesting applications of photonic crystals. We have observed a low threshold lasing in three-layer heterostructures opal films. The diffraction of light passing through a glass plate coated by an artificial single-crystal opal film has been analyzed. It has been shown that the stop band of a photonic crystal is manifested against the background of the unchanged spectrum of reflected and refracted Bragg waves. The position of this stop band can be changed under a small change in the concentration of a number of substances filling the photonic crystal. The application of such an optical system as an optical chemical sensor has been demonstrated.

In this paper Multi-walled Carbon Nanotubes (MWNTs) - based nanocomposite films were investigated as dynamic strain sensors for damage detection. After a thorough study to optimize the electromechanical properties of the material as a function of the MWNTs content, the proof-of-concept was carried out by installing the film onto the surface of a fiberglass cantilever. The cantilever was made to oscillate through an impulsive force applied at its free end. The free oscillations of the structure are monitored and the frequencies are identified before and after reducing locally the cross section of the cantilever (to simulate\ndamage propagation). The experimental data show the capability of the manufactured nanocomposite film to clearly identify structural frequencies in dynamic regimes. The obtained experimental data also show that this material has the potential to monitor incipient cracks (nano/micro-scaled cracks) due its sensitivity to nanoscale morphology changes