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This work investigates the influence of composition on the thermal properties of the high entropy alloy family Cu5Cr35Fe35V20-X5 (at. %), where X = Ti, Ta, W or Mo in the framework of acting as a thermal barrier between the W-based plasma-facing elements and the CuCrZr or Cu-based heat sink components of the fusion reactor. The alloys were produced by arc melting and their microstructure and mechanical properties were previously characterized by XRD, SEM, and Vickers hardness measurements. Thermal properties have been measured on as-cast at thermally treated alloys using the laser flash method in the temperature range 25 °C to 600 °C to determine the thermal diffusivity, α, thermal conductivity, λ, and specific heat, Cp. Dilatometry experiments were also carried out to obtain the linear thermal expansion coefficient, CTE, as a function of temperature.For all materials, the thermal conductivity increases with temperature from 15 W/m·K at RT to 28 W/m·K at 600 °C and does not significantly depend on the thermal treatment for the Mo-HEA and W-HEA, but increases after aging for the Ta-HEA and Ti-HEA. These values are lower than those of W (∼122 W/m·K at 600 °C) and much lower than for CuCrZr-IG (∼354 W/m·K at 400 °C). The thermal expansion coefficients of these HEAs, ∼10 × 10−6 °C−1 at RT and ∼ 2 × 10−6 °C−1 at 650 °C are between those of CuCrZr and the W for the entire operative temperature range. These results indicate that the Cu5Cr35Fe35V20-X5 (X = Ti, Ta, W, Mo) HEAs have a promising combination of the thermophysical properties, λ, Cp and CTE, to act as thermal barrier in plasma-facing components that require the union of W- and Cu-based materials.

Additive manufacturing (AM) is revolutionizing various industries by enabling the creation of complex structures with minimal waste. In the context of a circular economy, the importance of recycling cannot be overstated, as it plays a crucial role in reducing environmental impact and conserving resources. This study investigates the mechanical behavior of PETG in the context of recycling for 3D printing applications. With plastic waste posing significant environmental challenges, the pursuit of sustainable solutions is paramount. PETG has emerged as a promising material in additive manufacturing due to its favorable properties, but its sustainability remains a concern. Through mechanical testing, including tensile, compression, and impact tests, PETG specimens are evaluated after one cycle of recycling and reutilization

L’article propose une définition de la force illocutionnaire comme faisceau de potentialités non seulement de performance d’actes de parole pluriels, mais également de performativité plurielle dans les interactions verbales interpersonnelles et sociales. La thèse de la complexité modale de la force illocutionnaire et de la performativité plurielle qu’elle habilite est illustrée avec l’étude du reproche dans quatre espaces linguistiques et culturels : français métropolitain, anglais américain, arabe marocain et roumain. Le cadre de cette recherche est celui de la sémantique de l’(inter)action verbale – la SIV, développement d’une théorie plus générale du sens linguistique, de ses potentialités discursives et sémantiques, la Sémantique des Possibles Argumentatifs. Les données analysées sont issues d’une recherche expérimentale, portant aussi bien sur les savoirs déclaratifs que sur les savoir-faire langagiers de sujets parlants dans les 4 espaces linguistiques mentionnés.

The synthesis of polycrystalline TiFe2Sn samples by a route including arc melting and spark plasma sintering with Hf, Y, and In substitutions at the Ti and Sn sites is investigated. For a reduced amount of substitution, around 2 at%, the samples are single phase, while for increased amounts, secondary phases segregate. As is characteristic of these compounds, the Fe-Ti atomic disorder generates a weak ferromagnetic ordering, which is also influenced by the type of substitutional atoms and the secondary phases in the samples with a higher Hf content. The Seebeck coefficient values show an increase for Ti0.98Hf0.02Fe2Sn and for samples with an adjusted Sn content, resulting in slightly increased power factor values. These values reach a maximum for Ti0.98Hf0.02Fe2Sn at approximately 300 K and for TiFe2Sn1.05 at approximately 325 K, namely, 2.69 × 10⁻4 Wm−1K−2 and 2.52 × 10⁻4 Wm−1K−2, respectively. The thermal conductivity of all the samples with substitutions increases with respect to the pristine sample. The highest figure of merit value of 0.016 is also obtained for Ti0.98Hf0.02Fe2Sn at 325 K.

Due to their lightweight features and special energy absorption properties, metal foams (MFs) are gradually replacing fully-dense solid materials in top industries. Having a porous structure with thin cell-walls, MFs are quite sensitive to various operating conditions such as temperature (TT) and loading direction (LD), aspects that should not be neglected. However, the dual TT-LD impact on the mechanical behavior of anisotropic MFs has not yet been addressed. In this regard, the temperature range 25–550 °C (in steps of 75 °C) and the three orthogonal directions (X, Y and Z) were used to experimentally investigate the compressive crushing responses of MFs under the combined temperature-anisotropy effect. The studied MFs had closed cells and were manufactured from Al alloys (AlSi12Mg0.6) through powder metallurgy route. The main strength properties and energy absorption performance of the investigated foams were found to be strongly dependent on the LD and the TT. The best mechanical characteristics are highlighted by the Z-LD, followed in order by the Y and X directions. Thus, improvements in properties were obtained by over 45% (compressive modulus), 71% (compressive strength), 28% (densification strain) and 53% (energy absorption) for Z-LD compared to the other two LDs. Finally, the failure mechanisms differ considerably depending on the imposed test condition (TT or LD).

In this work, three methods for the synthesis of composites based on poly(ortho-toluidine) (POT) and WS2 are reported: (a) the solid-state interaction (SSI) of POT with WS2 nanoparticles (NPs); (b) the in situ chemical polymerization (ICP) of ortho-toluidine (OT); and (c) the electrochemical polymerization (ECP) of OT. The preparation of WS2 sheets was performed by the ball milling of the WS2 NPs followed by ultrasonication in the solvent N,N’-dimethyl formamide. During the synthesis of the POT/WS2 composites by SSI and ICP, an additional exfoliation of the WS2 NPs was reported. In this work, we demonstrated the following: (a) the ICP method leads to POT/WS2 composites, which contain repeating units of POT in the leucoemeraldine salt (LS) state, while (b) the ECP method leads to POT/WS2 composites, which contain repeating units of POT in the emeraldine salt (ES) state. Capacitances equal to 123.5, 465.76, and 751.6 mF cm−2 in the cases of POT-ES/WS2 composites, synthesized by SSI, ICP, and ECP, respectively, were reported.

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component’s section, structural transformations, and variations in the alloy’s properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy.

Mg2Si thermoelectric compound was obtained by dry and wet (isohexane and benzene) mechanical alloying route. The Mg2Si compound was characterised by X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), laser particle size analysis and thermoelectric measurements. After 14 h of milling, the complete reaction of the elements is achieved by both routes. The powders particle size distribution obtained after 14 h of dry or wet milling (using benzene) reveals a bimodal curve. The wet milling moves the particle size distribution towards smaller particle sizes. The SEM analysis confirms the results of particles size analysis. DSC analyses performed for samples milled up to 14 h present stress relief and recrystallisation thermal events. For the benzene wet-milled sample, the DSC curve shows an additional thermal event at 350 °C, associated with benzene removal. Thermoelectric properties were determined on spark plasma sintered compacts. The milling process with benzene leads to a higher value of Seebeck coefficient (≈580 μV/K). The electrical conductivity is low at room temperature and increases exponentially with temperature.

The synthesis of polycrystalline TiFe2Sn samples by a route including arc melting and spark plasma sintering with Hf, Y, and In substitutions at the Ti and Sn sites is investigated. For a reduced amount of substitution, around 2 at%, the samples are single phase, while for increased amounts, secondary phases segregate. As is characteristic of these compounds, the Fe-Ti atomic disorder generates a weak ferromagnetic ordering, which is also influenced by the type of substitutional atoms and the secondary phases in the samples with a higher Hf content. The Seebeck coefficient values show an increase for Ti0.98Hf0.02Fe2Sn and for samples with an adjusted Sn content, resulting in slightly increased power factor values. These values reach a maximum for Ti0.98Hf0.02Fe2Sn at approximately 300 K and for TiFe2Sn1.05 at approximately 325 K, namely, 2.69 × 10⁻4 Wm−1K−2 and 2.52 × 10⁻4 Wm−1K−2, respectively. The thermal conductivity of all the samples with substitutions increases with respect to the pristine sample. The highest figure of merit value of 0.016 is also obtained for Ti0.98Hf0.02Fe2Sn at 325 K. [ABSTRACT FROM AUTHOR]

Daylighting design is not only dimensioning glazed surfaces to provide sufficient natural light to an occupied space but also a method of analyzing how this can be achieved without unwanted effects, such as gains and losses of heat, glare, and variations in daylighting intensity at various indoor distances and levels. The case study presented in this paper highlights the energy consumed due to a group of windows with a large glazed area in an existing building located in a temperate continental climate area. The energy consumption results from supplementary artificial lighting required to maintain adequate illumination for indoor activities and to counterbalance heat loss during colder periods are evaluated. The analysis performed by modifying the glazed surface led to the identification of an optimum value of window dimensions for minimum energy consumption. The results of the case study highlight the fact that the evolution of the total energy consumption, evaluated as the sum of the energy consumption due to additional heating/cooling and the artificial lighting required to compensate for the reduction in natural light, is strongly influenced by the dimensions of the glazed surfaces, as well as the minimum level of lighting imposed by the regime of activities carried out in the building. Thus, the outcomes obtained in the research show that at lighting values below 500 lx, the total energy consumption is directly proportional to the glazed surface. From values of 500 lx for the illuminance level, the total energy consumption drops from 2730 kWh/year for a window height of 230 cm to 2399 kWh/year for a height of 110 cm, after which it starts to rise again, reaching a value of 2786 kWh/year for a height of 30 cm. This phenomenon is also found at values higher than 500 lx; accordingly, for an imposed lighting of 1000 lx, the minimum total consumption is identified at a window height of 150 cm. The case study presented in this paper clearly highlights a complex relationship between the height of the glazed surface and the energy consumption required to compensate for heating or cooling and the reduction in natural lighting. Lower window heights reduce heat loss or gain but also correspondingly increase the energy consumption of artificial lighting.

Helicobacter pylori (H. pylori) is a bacterium that colonizes the gastric mucosa and which is known for its ability to survive in the acidic environment of the stomach, thanks to its unique spiral shape and the presence of multiple flagella. Thus, H. pylori infection may present under the shape of multiple clinical entities and understanding its various facets is crucial for effective diagnosis and treatment. The importance of H. pylori infection in children lies in its potential to cause significant morbidity and long-term complications. This article aims to provide an overview of the importance of H. pylori infection in children, including its epidemiology, clinical manifestations, and treatment. Through a better understanding of this common infection, healthcare providers can work towards improving the diagnosis and management of H. pylori infection in children, ultimately improving the long-term health outcomes of affected individuals.

Pruritus represents a common and distressing feature of patients with chronic kidney disease (CKD). The severity of CKD associated pruritus (CKD-aP) can be assessed by using a visual analogue scale. Its presence is associated with a decreased quality of life, it contributes to the onset of other symptoms, it is correlated with depression, and represents an independent predictor of mortality. The aim of this article is to present the case of a 16 years old patient with end stage renal disease who developed CKD-aP in evolution, along with the apparition of other dermatological findings. Despite the adaptation of the dialysis prescription, the patient developed a severe uremic pruritus. Partial failure of numerous topical therapies associated with neuroleptics and sedatives was registered. The non-compliance to diet contributed to a slow amelioration of the symptoms. We highlight the importance of the correction of dialysis adequacy, phosphorus and calcium levels, along with skin hydration, nutrition, and patient education in an optimal outcome for pediatric patients with CKD-aP

Nephrotic syndrome represents one of the most frequent glomerular diseases among the pediatric population and while most of the children respond to steroid treatment, almost 20% of them are steroid-resistant. In this report, we present a case study of a 2 years old male with Steroid Resistant Nephrotic Syndrome (SRNS), complicated with spontaneous bacterial peritonitis and sepsis. We underline diagnostic and treatment challenges associated with this pathological entity, as patients with SRNS are at risk of developing chronic kidney disease (CKD), immunosuppressive-related complications as well as acute events such as thromboembolism. This field requires further in-depth studies, as the underlying immunological and genetic mechanisms are largely heterogenous, but we emphasize the multiple clinical-biological aspects that SRNS can present in a single patient, representing a real challenge in pediatric practice.

Gastroesophageal reflux becomes pathologic when the reflux episodes determine bothering symptoms and or complications. It is a pathology seen both in adults and children; in pediatric patients is a frequent reason for medical visits because of its symptoms that are bothersome both for children and caregivers, especially in infants. Usually, symptoms frequency declines by the age of one year old but when it persists practitioners must intervene with both general measures and medical treatment. The diagnostic is mainly clinical, but when other pathologies that can determine gastroesophageal reflux must pe excluded, imaging methods and esophageal pH measurement can be used.

Developing new materials to be applied in extreme environments is an opportunity and a challenge for the future. High entropy alloys are new materials that seem promising approaches to work in nuclear fusion reactors. In this work, FeTaTiVW high entropy alloys were developed and characterized with Molecular Dynamic and Hybrid Molecular Dynamic Monte Carlo simulations. The simulation results show that phase separation originates a lower potential energy per atom and a high level of segregation compared to those of a uniform solid solution. Moreover, the experimental diffractogram of the milled powder shows the formation of a body-centred cubic-type structure and the presence of TiO2. In addition, the microstructure of the consolidated material evidenced three phases: W-rich, Ti-rich, and a phase with all the elements. This phase separation observed in the microstructure agrees with the Hybrid Molecular Dynamic Monte Carlo simulation. Moreover, the consolidated material’s thermal conductivity and specific heat are almost constant from 25 °C to 1000 °C, and linear expansion increases with increasing temperature. On the other hand, specific heat and thermal expansion values are in between CuCrZr and W values (materials chosen for the reactor walls). The FeTaTiVW high entropy alloy evidences a ductile behaviour at 1000 °C. Therefore, the promising thermal properties of this system can be attributed to the multiple phases and systems with different compositions of the same elements, which is exciting for future developments.

Abstract Sesquipedalian mud and burnt bricks (second to third century AD) were excavated from the Roman city of Romula located in the Lower Danube Region (Olt county, Romania). Along with local soils, bricks are investigated by petrographic analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), electron microscopy (SEM/EDX), X-ray microtomography (XRT), thermal analysis (DTA-TG), Mӧssbauer spectroscopy, magnetometry, colorimetry, and mechanical properties assessment. The results correlate well with each other, being useful for conservation/restoration purposes and as reference data for other ceramic materials. Remarkably, our analysis and comparison with literature data indicate possible control and wise optimization by the ancient brickmakers through the recipe, design (size, shape, and micro/macrostructure), and technology of the desired physical–chemical–mechanical properties. We discuss the Roman bricks as materials that can adapt to external factors, similar, to some extent, to modern “smart” or “intelligent” materials. These features can explain their outstanding durability to changes of weather/climate and mechanical load.

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component's section, structural transformations, and variations in the alloy's properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy. [ABSTRACT FROM AUTHOR]

Abstract The present work reports a new configuration of soft artificial muscle based on a web of metal covered nylon 6/6 micrometric fibers attached to a thin polydimethylsiloxane (PDMS) film. The preparation process is simple and implies the attachment of metalized fiber networks to a PDMS sheet substrate while heating and applying compression. The resulting composite is versatile and can be cut in different shapes as a function of the application sought. When an electric current passes through the metallic web, heat is produced, leading to local dilatation and to subsequent controlled deformation. Because of this, the artificial muscle displays a fast and ample movement (maximum displacement of 0.8 cm) when applying a relatively low voltage (2.2 V), a consequence of the contrast between the thermal expanse coefficients of the PDMS substrate and of the web-like electrode. It was shown that the electrical current producing this effect can originate from both direct electric contacts, and untethered configurations i.e. radio frequency induced. Usually, for thermal activated actuators the heating is produced by using metallic films or conductive carbon-based materials, while here a fast heating/cooling process is obtained by using microfiber-based heaters. This new approach for untethered devices is an interesting path to follow, opening a wide range of applications were autonomous actuation and remote transfer of energy are needed.

In this work, three methods for the synthesis of composites based on poly(ortho-toluidine) (POT) and WS2 are reported: (a) the solid-state interaction (SSI) of POT with WS2 nanoparticles (NPs); (b) the in situ chemical polymerization (ICP) of ortho-toluidine (OT); and (c) the electrochemical polymerization (ECP) of OT. The preparation of WS2 sheets was performed by the ball milling of the WS2 NPs followed by ultrasonication in the solvent N,N'-dimethyl formamide. During the synthesis of the POT/WS2 composites by SSI and ICP, an additional exfoliation of the WS2 NPs was reported. In this work, we demonstrated the following: (a) the ICP method leads to POT/WS2 composites, which contain repeating units of POT in the leucoemeraldine salt (LS) state, while (b) the ECP method leads to POT/WS2 composites, which contain repeating units of POT in the emeraldine salt (ES) state. Capacitances equal to 123.5, 465.76, and 751.6 mF cm−2 in the cases of POT-ES/WS2 composites, synthesized by SSI, ICP, and ECP, respectively, were reported. [ABSTRACT FROM AUTHOR]