Nowadays, when renovating or building a new structure, thermal insulation is a crucial consideration in the construction process. For this, a wide variety of thermal insulation materials are available, as the industry's growth has been greatly aided by increasing environmental consciousness. As time goes on, the building's energy needs become more demanding, as everyone wants to reduce the amount of energy used for heating, which lowers carbon dioxide emissions that cause global warming. Moreover, thermal insulation is used not only on large flat surfaces, but also on building mechanical equipment and pipelines, and as a supplement to address thermal bridges. For these new materials that have arisen on the market, such as aerogels and sprayed polyurethane foam, as well as the combination of different materials in composites. In this article, we aim to present thermal investigations conducted on a new type of polymeric foam (polyurethane) aerogel composite mixture with 30 and 48% aerogel content. We created two composites by mixing sprayable polyurethanes and aerogel particles. We will present thermal conductivity measurement results with 8-18% reduction in thermal conductivity. Moreover, we present thermal conductivity models to better analyse the modification in heat transfer. Furthermore, calorimetric measurements (DSC and bomb calorimetry) were accompanied by optical microscopy images and hydrophobicity tests. We also present the compressibility test results. Our results indicate that the combination of these materials will have significantly better thermal properties than either one alone. We will also show that the samples became more flame-retardant (lower combustion heat) and hydrophobic. Furthermore, we showed a decrease in mechanical properties after adding aerogel particles.

Objectives To evaluate the effect of different surface pretreatment protocols on the repair bond strength and integrity of resin composite to three different resin matrix ceramics (RMCs). Material and Methods Three RMCs - Cerasmart (CS), Grandio blocs (GB) and Katana Avencia (KA) - were subjected to one of three mechanical surface treatments: polishing, diamond bur roughening, or sandblasting. These were randomly assigned to four conditioning groups: 10-MDP and silane-containing adhesive (Clearfil Universal Bond Quick), 10-MDP-based adhesive (G-Premio Bond), 9% buffered hydrofluoric acid (HF) plus silane, and a 10-MDP and silane-free adhesive (Heliobond). A nanohybrid composite (Reflectys) was applied as the repair material. Specimens were sectioned into sticks and subjected to micro-tensile bond strength (µTBS) testing using a universal testing machine. The surface treatments were compared by one-way ANOVA and post-hoc tests for different cases of the variables µTBS and surface roughness. Results For CS, the combination of sandblasting and 10-MDP plus silane-containing adhesive yielded the highest µTBS (46.42 ± 3.12 MPa), with no significant difference observed between polishing and bur roughening. Similarly, GB showed significantly higher µTBS when sandblasted and treated with 10-MDP plus silane adhesive (42.01 ± 5.06 MPa). However, for KA, the most effective protocol was the combination of sandblasting and 9% buffered HF with silane (48.31 ± 8.46 MPa). Conclusions Repair bond strength is highly dependent on the specific RMC used. No single universal mechanical surface treatment or conditioning protocol was found to be optimal across all materials. Clinicians should utilise individualised repair protocols - specifically 10-MDP and silane-containing adhesives for CS and GB, and HF and silane for KA - to achieve maximum repair bond strength. Clinical Significance When repairing RMC restorations chairside, clinicians should identify the specific material brand, whenever possible, as the chemical composition of the RMC dictates whether a universal adhesive or a traditional HF and silane protocol will provide the most durable immediate repair.

Objectives:The aim was to compare the two-body wear behavior of four nanocomposites used for enamel replacement. Materials and Methods:Nanocomposite specimens (Estelite Asteria [EA], Enamel Biofunction [EBF], Neospectra [NS], Clearfil Majesty [CM]; n = 8 for each, diameter = 10 mm, height = 1.5-2 mm) were prepared in a custom-made mold according to the manufacturer's instructions. The degree of conversion (DC) was measured by Fourier transform infrared spectroscopy. Vickers hardness (VH) was measured on the top and bottom surfaces, and the VH ratio (VHR) was calculated. The specimens were aged using a thermocycling machine (10,000 cycles), followed by 120,000 chewing cycles. The mean volume loss (MVL), maximum wear depth (MWD), and surface roughness (SR) were assessed with a white-light interferometer. The tested surfaces before and after the wear test, along with the morphology of extracted fillers, were evaluated using scanning electron microscopy (SEM). Statistical analysis-ANOVA, Levene, Tukey, and Tamhane tests-was performed with SPSS Statistics version 28. Results:CM exhibited a significantly higher VH compared to the other nanocomposites, both before and after aging. It also showed lower MVL, MWD, and SR than the other three tested nanocomposites. Conclusions:VH and wear behavior are significantly affected by the filler parameters of nanocomposites. Clinical Significance:This study may assist clinicians in selecting resin-based composite (RBC) for occlusal rehabilitation. Based on this in vitro study, CM exhibited a lower wear rate than the other tested RBCs; therefore, it is worth considering its use for patients with higher bite forces.

Most power plants and district heating systems employ rock wool or ceramic fiberglass insulations to insulate their pipes. Over time, these materials lose some qualities. The present study tested two thermal insulation materials for applications in pipelines carrying hot steam in power plants or district heating (DH) systems: ceramic fiberglass (insulfrax) and flexible mineral wool. Thermal conductivity was measured at high temperatures (150 and 250 degrees C), simulating the effect of the passage of time. It was found that insulfrax had lower thermal conductivity in all cases 0.025-0.031 W/mK, compared to the mineral wool (0.038-0.422 W/mK). However, thermal conductivity of the mineral wool was continuously increasing (3 % and 9 %), and the thermal conductivity of the insulfrax jumped only after thermal annealing at 250 degrees C, but by about 24 %. Scanning electron microscopic imaging and differential scanning calorimetry experiments were used to reveal any possible changes in the structures of the materials after thermal annealing them at 150 and 250 degrees C for 1 day. The change in the specific heat was also calculated with differential scanning calorimetry, and crystallization processes were deduced. Finally, a comparative life cycle assessment was applied to select materials based on environmental performance, aligning with the Sustainable Development Goals requirements.

Low‐dimensional copper halides with perovskite–analogue structure are a rapidly growing material family for light‐emitting and X‐ray screening devices. Among them Cs3Cu2I5 exhibits exceptional optoelectronic properties (large Stokes shift, high emission yield), due to the strong confinement effect of its 0D structure. However, its radioluminescence response to energetic ions has only marginally been explored and to heavy ions fully ignored due to the detrimental effect of luminescence quenching. Herein, the scintillation response of Cs3Cu2I5 thin layers to ions in a wide range of atomic mass and ionization density, as well as to electrons using the Compton‐coincidence technique, is investigated. The photon yield, linearity, and energy resolution are investigated as key parameters of the spectroscopic performance. Different semiempirical quenching models are used to better understand the relationship between the luminescence yield and the ionization density. The spectroscopic capability of polycrystalline Cs3Cu2I5 thin films is found on par with that of single‐crystal CsI:Tl to detect heavy ions. This makes easily processable thin‐film copper halides an attractive addition to the scintillator landscape.

Nanoparticles exhibit diverse effects when added as additives to oily medium, enhancing tribological properties and surface characteristics. Studies have shown that many oxide ceramic nanoparticles improve friction and wear, while mixtures also demonstrate favorable tribological properties. This study explores the tribological effect of an yttria–silica (Y2O3, SiO2) nanoparticle mixture in a Group III base oil medium. The results reveal that the yttria–silica mixture significantly reduces friction (−8–17%), mean wear scar diameter (−32%), and wear volume (−94%), while increasing load-bearing capacity (+114%) by creating a durable boundary layer. Observations from scanning electron microscopy revealed the original surface is protected. EDX analyses highlight the boundary layer’s elemental composition, which is high in yttrium, silicon, and oxygen and found in higher areas. XRD analysis could not detect the yttria nanoparticle additive within the boundary layer, suggesting that it fragmented due to sliding stress, resulting in an amorphous structure for the new boundary layer. TEM imaging confirmed that the boundary layer thickness is 40–45 nm. These findings demonstrate significant potential for industrial applications in developing advanced, high-performance lubricants for demanding mechanical systems.

Amorphous lead oxide (a-PbO) X-ray photoconductors show potential for applications in direct conversion medical imaging detectors within the diagnostic energy range. a-PbO enables large-area deposition at low temperatures and exhibits no signal lag. Low dark current can be maintained through specialized blocking layers, similar to those used in multilayer amorphous selenium (a-Se) structures in commercial detectors. However, the current state of a-PbO technology faces challenges in thick layer deposition, leading to crystalline inclusions and cracks. Our proposed stress-induced crystallization model reveals that intrinsic stress in a-PbO layers amplifies with thickness, leading to crystallographic defects. These defects, which are associated with the stable phase of β-PbO, contribute to increased dark current and initiate layer cracking. We calculate the thermal expansion coefficient of a-PbO, indicating a thermomechanical mismatch between the photoconductor and the substrate as the primary source of stress. Furthermore, we demonstrate that layer deposition parameters significantly impact heat accumulation within the growing layer, thereby facilitating temperature-induced crystallization. Our study suggests that relieving stress in grown a-PbO layers by eliminating thermal expansion coefficient mismatches between different layers in a-PbO blocking structures, coupled with optimizing deposition parameters to prevent heat accumulation during layer growth, may inhibit or even prevent stress-induced crystallization and the emergence of structural defects in thick a-PbO layers.

Different drug delivery systems are formulated from chemically identical borosilicate-alginate xerogels and aerogels. The backbones of these gels are prepared in a common sol-gel procedure, but the loading of the nicotinic acid drug, as well as the final drying of the impregnated wet gels were realized using different strategies. It is shown that adding the nicotinic acid during gelation and drying the wet gel under ambient conditions leads to dense xerogels with high drug loading, which is released in a moderately retarded manner in simulated gastric and intestinal fluids. Highly porous aerogels are also formulated from the identical wet gels that are impregnated with nicotinic acid post-gelation and dried using supercritical CO2. Nicotinic acid is deposited in an amorphous form in these aerogels, and the drug dissolves practically instantaneously in the mentioned simulated body fluids. Supercritical CO2 drying is essential to achieve the advantageous drug solubilization feature, because drying identical gels under ambient pressure yielded xerogels that do not display burst drug release. The thorough characterization (SEM, EDS, N2-sorption, XRD, FT-IR, Raman spectroscopy, zeta-potential) of the different gel formulations reveals the most important chemical and morphological features that control the distinct mechanisms of the release of nicotinic acid from the different gels.

In this study, we report the findings of a morphological analysis of a resorcinol-formaldehyde (RF)-based carbon aerogel (CA) and its graphene oxide (GO)-doped version (CA-GO), prepared for possible applications as an electrode material. Beyond some electron microscopic and N2 sorption investigations, we mostly used NMR cryoporometry and relaxometry to characterize the gels in a wet state, as they are usually applied. The precursor RF polymer aerogel was prepared both with and without GO and was subsequently carbonized into carbon aerogel. Modifying the polymer aerogel using GO resulted in a larger variety of C-O bonds in both polymer aerogels. However, the most important changes occurred in the morphology of the carbon aerogels. NMR relaxometry revealed the highly hydrophilic nature of the pore wall of the RF polymer aerogels, as demonstrated by their uniform wetting behavior. The carbonization resulted in a mostly hydrophobic pore wall decorated by some oxygen-containing spots and a macroporous system. Doping with GO after pyrolysis resulted in spherical pores in the CA and cylindrical pores in the CA-GO, which is potentially a more promising material for electrochemical use than CA.

Auger-emitting radionuclides, exemplified by Pd-103, exhibit considerable therapeutic potential in cancer treatment due to their high cytotoxicity and localized biological impact. Despite these advantages, the separation of such radionuclides presents a complicated challenge, requiring intricate and time-intensive “wet chemistry” methods attributed to the exceptional chemical inertness of the associated metals. This study proposes an innovative solution to this separation challenge through the design and implementation of a piece of radionuclide separation equipment (RSE). The equipment employs a dry distillation approach, capitalizing on differences in partial vapor pressures between irradiated and resulting radioactive metals, with a diffusion-driven extraction method applied to separate Pd-103 radionuclides generated via the proton irradiation of Rh-103 at cyclotron. Our optimization endeavors focused on determining the optimal temperature for effective metal separation and adjusting the diffusion, evaporation, and deposition rates, as well as addressing chemical impurities. The calculations indicate 17% ± 2% separation efficiency with our RSE. Approximately 77 ± 2% and 49 ± 2% of the deposited Pd-103 were isolated on substrates of Nb foil and ZnO-covered W disc, respectively. The proposed innovative dry distillation method that has been experimentally tested offers a promising alternative to conventional separation techniques, enabling enhanced purity and cost-efficient cancer treatment strategies.

Ternary copper halide pseudo‐perovskites are in the forefront of research as potential active materials in light emission applications. The optoelectronic properties of these compounds can be fine‐tuned by the preparation of mixed‐halide compositions. After irradiation, self‐trapped excitonic states are formed in these materials. However, the emission from these self‐trapped states is not yet fully understood. In this work, mixed‐halide Cs 3 Cu 2 X 5 films (where X: I and/or Br) are prepared by a simple spray‐coating method. Using ultraviolet photoelectron spectroscopy, the changes in optoelectronic properties are linked to the electronic structure of these materials. It is revealed that the incorporation of bromide into the lattice makes the emission process of these materials more vulnerable to trap states. By combining the different spectroscopic characterization techniques, the exact band structure of these compounds is determined, and the different processes are translated to the absolute energy scale. As an alternative excitation mechanism of self‐trapped states, α ‐particles are used to induce radioluminescence response. The Cs 3 Cu 2 X 5 films exhibit composite decay patterns, most likely attributed to a multitude of different trap state‐mediated recombination processes.

ABSTRACT Excavation campaigns conducted at the Pécel‐Kis hársas site (Hungary) between 2014 and 2017 yielded the remains of a mature female woolly rhinoceros ( Coelodonta antiquitatis ) and six lithic artefacts. Radiocarbon dating confirmed that the rhinoceros died ca. 20.4k cal a bp , at the very end of the Last Glacial Maximum and, considering the position of the artefacts when found, it was probably killed by Epigravettian hunters. Based on dental analyses of the specimen, a vigorous lichen‐ (and possibly moss‐)consuming diet could be inferred for the end of the animal's lifetime. Based on Sr results, we can exclude the possibility of long‐range migration. In accordance with the optimum environmental demands of the foraging lichen, the low δ 18 O value of osseous material implies a relatively cold contemporaneous climate with a calculated mean annual air temperature of around 0.7 °C. Meanwhile, the extremely low δ 15 N value may have resulted from the proximity of the discontinuous permafrost zone and some intensive soil dislocation. Consequently, poor vegetation and an open, tundra‐like habitat can be assumed to have been dominant at the site at that time, which is also supported by palaeoenvironmental modeling experiments.

Analysis of phytoliths (plant silica bodies) still may have an unrevealed potential in paleoenvironmental reconstruction studies. This can provide novel findings in research on environmental change as phytoliths play an important role in the silicon biogeochemical cycle. In favorable environmental conditions, Picea abies [L.] H. Karst (Norway spruce) needles develop a phytolith layer consisting of more or less cubical or cuboid (blocky) phytoliths in their transfusion tissue that becomes continuous toward the apex of the needle. This can be studied in situ in fossil (subfossil) needles under a stereomicroscope. This study reports the blocky-type phytolith preservation in fossil spruce needles in sediment sections of the lake Černé jezero (Bohemian Forest, Czech Republic). The oldest needle containing phytoliths was 7.8 cal ka BP. Despite differences in the Energy Dispersive X-ray (EDX) spectra of different age phytoliths, the studied subfossil phytoliths did not lose their globular ultrastructure in the needle tissue, proving the stability of this phytolith morphotype. As the tissue of the needle fossils can preserve phytoliths in situ, further micro-analytical measurements will make these needles promising tools for paleoenvironmental reconstructions. The most favorable period for spruce phytolith formation for the studied region appears to be the period 6.0–4.5 cal ka BP, within the Holocene Climate Optimum period. In order to use these phytoliths as a terrestrial climate proxy, the next step is to refine their sensitivity to environmental changes.

Super thermal insulation materials with low thermal conductivities, such as aerogels and vacuum insulation panels, are increasingly pushing conventional thermal insulations out of the market. Super insulation materials such as aerogels can be used easily on both vehicles and buildings. Nowadays, their usage by pipes transporting hot medium is also widespread. In these environments where elevated temperatures (100-250 degrees C) are applied, it is a basic requirement that they should keep their excellent thermal insulating capability. In this study, a comprehensive examination performed on two new silica-aerogel type insulations is presented. We investigated the change in the thermal performance of different types of aerogel insulations (Slentex and Pyrogel) after thermal annealing, ageing them at 150 and 250 degrees C temperatures for 1 day. After these thermal treatments, their thermal parameters such as thermal conductivities and specific heat capacities were measured. We revealed that both the thermal conductivity and the specific heat capacity for the Pyrogel changed considerably after annealing, while for Slentex the thermal conductivity remained constant and the specific heat capacity changed. To understand these changes we executed calorimetry tests and microscopic inspections with different methods. These experiments were completed with X-ray diffractometry to analyze the possible structural changes in the samples. From an application point of view, we consider the importance of these results, since they predict the lifetime of the used insulating material during their industrial use.

The passivity of aluminum is detrimental to its performance as an anode in batteries. Soaking of native oxide-covered aluminum in a chloroaluminate deep eutectic solvent gradually activates the electrode surface, which is reflected in a continuously decreasing open circuit potential. The underlying processes were studied by analyzing the 3 to 7 nm thick layer of native oxide after increasing periods of soaking with secondary neutral mass spectrometry, X-ray photoelectron spectroscopy, and energy-dispersive spectroscopy in a transmission electron microscope. They consistently show permeation of electrolyte species into the layer associated with gradual swelling. After extended periods of soaking at open circuit potentials, local deposits of a range of foreign metals have been found in scanning electron microscopy images of the electrode surface. The pitting corrosion is caused by trace metal ion impurities present in the electrolyte and results in highly nonuniform current density distribution during discharge/charge cycling of battery cells as shown by local deposits of aluminum. The processes during soaking at open circuit potentials have been monitored by electrochemical impedance spectroscopy and could be analyzed by fitting an equivalent circuit model for pitting corrosion.

This article investigates the photoinduced changes (PICs) in the optical properties of As2S3 impregnated in porous glasses (PGs) and the influence of gold nanoparticles (AuNPs). The composite material was obtained via a simple chemical deposition method where As2S3 powder was dissolved in an amine solution and impregnated into PG pieces, with and without the addition of AuNPs. Using Fourier-transform infrared spectroscopy, it was confirmed that, when mixing solutions of As2S3 and AuNPs they interact and form complexes that result in the plasmonic resonance suppression of AuNPs. Upon irradiation using green laser (532 nm) a significant increase in the bandgap energies of the samples was observed. This effect was studied using Raman spectroscopy. Moreover, it was noticed that the change in the bandgap energy depends on the As2S3 concentration and is reduced by the presence of AuNPs.

Nowadays, if one wants to renovate or build a building, the question of thermal insulation is an essential construction process. Polyurethane is a key thermal insulation material that belongs to plastic foams. It can be applied as a spread or board heat-insulating material. Its thermal insulation properties are superior compared to polystyrene, but still a bit neglected. In this article, we would like to perform thermal investigations executed on a new type of polymeric foam such as polyisocyanurate. We will present acceptably low thermal conductivity (~ 0.022 W m -1 k -1 ), raised specific heat capacity (~ 1400 J kg -1 K -1 ) and calorimetric (bomb and differential) measurement results completed with optical microscopic images. Moreover, scanning electron microscopic analysis and X-ray diffractometry will be also presented. The results will be used for cost calculations applied by buildings and will show justified reasons for its application based on structural measurements too. The results are extremely encouraging.

The surface roughness, surface free energy (SFE) of composites, and composite wettability by dental adhesives are determining factors in achieving a strong and durable adhesion (e.g., composite repair, luting adhesively bonded indirect restorations). In this study, the SFE of one nanohydrid and two bulk-fill composites was investigated in relation to the wetting ability of five different dental adhesives. The profilometry and scanning electron microscopy (SEM) measurement justified that the sandblasting produced a significantly rough surface in which the different filler amounts, filler distribution, and resin-filler ratio participated. The SFE of the tested composite was between 45.65 and 49.07 mJ/m2 regardless of surface treatment. Despite the similarity in SFE, the adhesives wet the surface of the composites in different ways that were between 16.01° and 35.10°. The contact angle of solvent-free dental adhesive was lower due to sandblasting supporting the micromechanical retention. Based on our results, it was found that sandblasting, the most frequently recommended surface treatment, does not change the surface energy but causes a change in the contact angle, which can be explained by the different surface tension of the dental adhesives. It was concluded that the dental adhesive parameters have a more important role in wettability.

The in situ application of the combination of different types of drugs revolutionized the area of periodontal therapy. The purpose of this study was to develop nanocomposite hydrogel (NCHG) as a pH-sensitive drug delivery system. To achieve local applicability of the NCHG in dental practice, routinely used blue-light photopolymerization was chosen for preparation. The setting time was 60 s, which resulted in stable hydrogel structures. Universal Britton–Robinson buffer solutions were used to investigate the effect of pH in the range 4–12 on the release of drugs that can be used in the periodontal pocket. Metronidazole was released from the NCHGs within 12 h, but chlorhexidine showed a much longer elution time with strong pH dependence, which lasted more than 7 days as it was corroborated by the bactericidal effect. The biocompatibility of the NCHGs was proven by Alamar-blue test and the effectiveness of drug release in the acidic medium was also demonstrated. This fast photo-polymerizable NCHG can help to establish a locally applicable combined drug delivery system which can be loaded with the required amount of medicines and can reduce the side effects of the systemic use of drugs that have to be used in high doses to reach an ideal concentration locally.

On the example of the PbTe compound we present the results of the study of the interplay between the crystallographic orientation of the surfaces of high reticular density and easy cleaving of the crystals of cubic symmetry and the shape of surface structures induced by prolonged ion sputtering. We found that in case of right combination of the crystallographic orientation of both the sputtering surface and the planes of high reticular density in the aggregate with easy cleaving of the crystals, the pyramidal structures of pseudo-hexagonal shape can be formed on the sputtering surface of cubic crystals. In case of PbTe these are the surfaces of (111) crystallographic orientation subject to the presence of sputter-resistant protective shields on them. When the protective shields are destroyed, the hexagonal structures are transformed into trihedral pyramids. The pseudo-hexagonal pyramidal structures are characterized by indistinct edges and terrace-shaped lateral facets, whereas the facets of the trihedral pyramids, into which they are transformed during the ion bombardment, are mirror-smooth. We prove that: (a) the maximally sharpened pseudo-hexagonal pyramids, ion-induced on PbTe (111) sputtering surfaces, are formed as a result of self-organization of the crystallographic planes of the family {0ī2}, the reticular density of which directly follows the reticular density of the plane of the sputtered surface; (b) the roughness of the lateral facets of pseudo-hexagonal pyramids, as well as the mirroring of the facets of the trihedral pyramids is due to the impact of crystallographic planes of the {100}family, which are the planes of the greatest reticular density and easiest cleaving for PbTe crystals.