Search Results (748)

With the growing severity of environmental pollution, people are paying increasing attention to their health. However, naturally occurring wood with health benefits and applications in human healthcare is still scarce. Natural wood exhibits a limited negative oxygen ion release capacity, and this release has a short duration, failing to meet practical application requirements. This study innovatively developed a humidity-responsive, healthy wood material with a high negative oxygen ion release capacity based on fast-growing poplar. Through vacuum cyclic impregnation technology, hexagonal stone powder was infused into the pores of poplar wood, endowing it with the ability to continuously release negative oxygen ions. The healthy wood demonstrated a static average negative oxygen ion release rate of 537 ions/cm³ (peaking at 617 ions/cm³) and a dynamic average release rate of 3,170 ions/cm³ (peaking at 10,590 ions/cm³). The results showed that the particle size of hexagonal stone powder in suspension was influenced by the dispersants and dispersion processes. The composite dispersion process demonstrated optimal performance when using 0.5 wt% silane coupling agent γ-(methacryloxy)propyltrimethoxysilane (KH570), achieving the smallest particle size of 8.93 μm. The healthy wood demonstrated excellent impregnation performance, with a weight gain exceeding 14.61% and a liquid absorption rate surpassing 165.18%. The optimal impregnation cycle for vacuum circulation technology was determined to be six cycles, regardless of the type of dispersant. Compared with poplar wood, the hygroscopic swelling rate of healthy wood was lower, especially in PEG-treated samples, where the tangential, radial, longitudinal, and volumetric swelling rates decreased by 70.93%, 71.67%, 69.41%, and 71.35%, respectively. Combining hexagonal stone powder with fast-growing poplar wood can effectively enhance the release of negative oxygen ions. The static average release of negative oxygen ions from healthy wood is 1.44 times that of untreated hexagonal stone powder, and the dynamic release reaches 2 to 3 times the concentration of negative oxygen ions specified by national fresh air standards. The water-responsive mechanism revealed that negative oxygen ion release surged when ambient humidity exceeded 70%. This work proposes a sustainable and effective method to prepare healthy wood with permanent negative oxygen ion release capability. It demonstrates great potential for improving indoor air quality and enhancing human health. Full article

Spruce wood is a natural polymeric material, consisting of cellulose, lignin, hemicelluloses and other secondary components, which gives it a unique chemical footprint and architecture. Varnishes are used in musical instruments to protect the wood against humidity variations, wood being a hygroscopic material, but also to protect the wood from dirt. The varnishes used both to protect the wood from resonance and to ensure a special aesthetic appearance are either polymeric varnishes (nitrocellulose, oil-based) or volatile solvents (spirit). In this study, the color changes, the surface morphology and the chemical spectrum produced by three types of varnishes, applied in 5, 10 and 15 layers, on resonance spruce plates were analyzed. The results revealed significant changes in the color parameters: the lightness decreased by approximately 17% after the first layer, by 50% after 5 layers, by 65% after 10 layers and by 70% after 15 layers. The color parameters are most influenced by the anatomical quality of spruce wood (annual ring width and earlywood/latewood ratio) in the case of oil-based varnishes and least influenced in the case of nitrocellulose varnishes. The chemical fingerprint was determined by FTIR spectrum analysis, which revealed that the most pronounced absorptions were the double band 2926–2858 cm⁻¹, corresponding to aliphatic methylene and methyl groups (asymmetric and symmetrical C-H stretch), and the bands at 1724 cm⁻¹ (oil-based varnish), 1722 cm⁻¹ (nitrocellulose varnish) and 1708 cm⁻¹ (spirit varnish), all assigned to non-conjugated carbonyl groups in either carboxylic acids, esters aldehydes or ketones. The novelty of the study lies in the comparative analysis of three types of varnishes used in the musical instrument industry, applied to samples of spruce resonance wood with different macroscopic characteristics in three different layer thicknesses. Full article

Kefiran, the extracellular polysaccharide produced from the Generally Recognized as Safe (GRAS) bacteria in kefir grains, with its well-documented functional and health-promoting properties, constitutes a promising biopolymer with a variety of possible uses. Its compatibility with other biopolymers, such as milk proteins, and its ability to form standalone cryogels allow it to be utilized for the fabrication of films with improved properties for applications in the food and biomedical–pharmaceutical industries. In the present work, the properties of kefiran films were investigated in the presence of milk proteins (sodium caseinate, native and heat-treated whey proteins, and their mixtures), alongside glycerol (as a plasticizer) and cryo-treatment of the film-forming solution prior to drying. A total of 24 kefiran films were fabricated and studied for their physical (thickness, moisture content, water solubility, color parameters and vapor adsorption), mechanical (tensile strength and elongation at break), and optical properties. Milk proteins increased film thickness, solubility and tensile strength and reduced water vapor adsorption. The hygroscopic effect of glycerol was mitigated in the presence of milk proteins and/or the application of cryo-treatment. Glycerol was the most effective at reducing the films’ opacity. Heat treatment of whey proteins proved to be the most effective in increasing film tensile strength, reducing, at the same time, the elongation at break, while sodium caseinates in combination with cryo-treatment resulted in films with high tensile strength and the highest elongation at break. Cryo-treatment, carried out in the present study through freezing followed by gradual thawing of the film-forming solution, proved to be the most effective factor in decreasing film roughness. Based on our results, proper selection of the film-forming solution composition and its treatment prior to drying can result in kefiran–glycerol films with favorable properties for particular applications. Full article

After the first release of synthalin B (dodecamethylenbiguanide) in 1928 and its later retraction in the 1940s in Germany, the retraction of phenformin (N-Phenethylbiguanide) and of Buformin in the USA (but not outside) because of the lethal complication of acidosis seemed to have put an end to the era of the biguanides as oral antidiabetics. The strongly hygroscopic metformin (1-1-dimethylbiguanide), first synthesized 1922 and resuscitated as an oral antidiabetic (type 2 of the elderly) compound first released in 1959 in France and in other European countries, was used in the first large multicenter prospective long-term trial in England in the UKPDS (1977–1997). It was then released in the USA after a short-term prospective trial in healthy overweight “young” type 2 diabetics (mean age 53 years) in 1995 for oral treatment of type 2 diabetes. It was, however, prescribed to mostly multimorbid older patients (above 60–65 years of age). Metformin is now the most used oral drug for type 2 diabetes worldwide. While intravenous administration of biguanides does not have any glucose-lowering effect, their oral administration leads to enormous increase in their intestinal concentration (up to 300-fold compared to that measured in the blood), to reduced absorption of glucose from the diet, to increased excretion of glucose through the stool, and to decrease in insulin serum level through increased hepatic uptake and decreased production. Intravenously injected F18-labeled glucose in metformin-treated type 2 diabetics accumulates in the small and even more in the large intestine. The densitometry picture observed in metformin-treated overweight diabetics is like that observed in patients after bowel-cleansing or chronically taking different types of laxatives, where the accumulated radioactivity can even reach values observed in colon cancer. The glucose-lowering mechanism of action of metformin is therefore not only due to inhibition of glucose uptake in the small intestine but also to “attraction” of glucose from the hepatocyte into the intestine, possibly through the insulin-mediated uptake in the hepatocyte and its secretion into the bile. Furthermore, these compounds have also a diuretic effect (loss of sodium and water in the urine) Acute gastrointestinal side effects accompanied by fluid loss often lead to the drugs’ dose reduction and strongly limit adherence to therapy. Main long-term consequences are “chronic” dehydration, deficiency of vitamin B12 and of iron, and, as observed for all the biguanides, to “chronic” increase in fasting and postprandial lactate plasma level as a laboratory marker of a clinical condition characterized by hypotension, oliguria, adynamia, and evident lactic acidosis. Metformin is not different from the other biguanides: synthalin B, buformin, and phenformin. The mechanism of action of the biguanides as antihyperglycemic substances and their side effects are comparable if not even stronger (abdominal pain, nausea, vomiting, diarrhea, fluid loss) to those of laxatives. Full article

This study aimed to microencapsulate Boesenbergia rotunda (fingerroot) extract using maltodextrin (MD) and gum arabic (GA) as wall materials via spray-drying to improve powder physicochemical properties and protect bioactive compounds. MD and GA were employed as wall materials in varying ratios (MD:GA of 1:0, 0:1, 1:1, 2:1, 1:2) to evaluate their effects on the physicochemical properties of the resulting microcapsules. Spray-dried microcapsules were evaluated for morphology, flowability, particle size distribution, moisture content, hygroscopicity, solubility, encapsulation efficiency, major bioactive compound retention, and thermal stability. The extract encapsulation using MD:GA at 1:1 ratio (MD1GA1) demonstrated a favorable balance, with high solubility (98.70%), low moisture content (8.69%), low hygroscopicity (5.08%), and uniform particle morphology, despite its moderate EE (75.06%). SEM images revealed spherical particles with fewer surface indentations in MD-rich formulations. Microencapsulation effectively retained pinostrobin and pinocembrin in all formulations with pinostrobin consistently retained at a higher value, indicating its higher stability. The balanced profile of physical and functional properties of fingerroot extract with MD1GA1 microcapsule makes it a promising candidate for food and nutraceutical applications. Full article

This study evaluated and compared two encapsulation techniques—co-crystallization and ionic gelation—for stabilizing bioactive components derived from lavender distillation residues. Utilizing aqueous ethanol extraction (solid residues) and concentration (liquid residues), phenolic-rich extracts were incorporated into encapsulation matrices and processed under controlled conditions. Comprehensive characterization included encapsulation efficiency (Ef), antioxidant activity (AA), moisture content, hygroscopicity, dissolution time, bulk density, and color parameters (L*, a*, b*). Co-crystallization outperformed ionic gelation across most criteria, achieving significantly higher Ef (>150%) and superior functional properties such as lower moisture content (<0.5%), negative hygroscopicity (−6%), and faster dissolution (<60 s). These features suggested enhanced physicochemical stability and suitability for applications requiring long shelf life and rapid solubility. In contrast, extruded beads exhibited high moisture levels (94.0–95.4%) but allowed better control over morphological features. The work introduced a mild-processing approach applied innovatively to the valorization of lavender distillation waste through structurally stable phenolic delivery systems. By systematically benchmarking two distinct encapsulation strategies under equivalent formulation conditions, this study advanced current understanding in bioactive microencapsulation and offers new tools for developing functional ingredients from aromatic plant by-products. Full article

This paper presents a novel, non-contact method for measuring capillary water uptake in porous materials based on the phenomenon of moisture-induced expansion. The proposed approach establishes a quantitative relationship between the amount of water absorbed by the material and the deformations measured on its surface. Digital Image Correlation (DIC) was used to track the displacements of reference points on gypsum specimens during capillary rise. The absorbed water mass was determined from the recorded displacements using a mechanical model that incorporates the moisture expansion coefficient. The method was validated by comparison with conventional continuous gravimetric measurements. The results demonstrate that the displacement-based approach accurately captures the capillary rise process, particularly in the initial phase, where the gravimetric method suffers from significant measurement errors due to surface tension effects. The proposed method eliminates these limitations, providing higher accuracy and temporal resolution. In addition, it enables the testing of larger samples and offers the potential for spatially resolved moisture analysis. The findings confirm that the method is suitable for studying moisture transport in porous materials and may serve as a valuable alternative to traditional gravimetric techniques. Full article

As semiconductor devices demand higher input–output density and faster signal transmission, fan-out panel-level packaging has emerged as a promising solution for next-generation electronic systems. However, the hygroscopic nature of epoxy molding compounds raises critical reliability concerns under high-temperature and high-humidity conditions. This study investigates the hygrothermal stress of a single fan-out panel-level package unit through experimental characterization and numerical simulation. Thermal–mechanical analysis was conducted at 100 °C and 260 °C to evaluate the strain behavior of two commercial epoxy molding compounds in granule form after moisture saturation. The coefficient of moisture expansion was calculated by correlating strain variation with moisture uptake obtained under 85 °C and 85% relative humidity, corresponding to moisture sensitivity level 1 conditions. These values were directly considered into a moisture -thermal coupled finite element analysis. The simulation results under reflow conditions demonstrate accurate principal stress and failure location predictions, with stress concentrations primarily observed at the die corners. The results confirm that thermal effects influence stress development more than moisture effects. Finally, a structural sensitivity analysis of the single-package configuration showed that optimizing the thickness of the dies and epoxy molding compound can reduce maximum principal stress by up to 12.4%, providing design insights for improving package-level reliability. Full article

This study describes a quite special and interesting atmospheric event characterized by the simultaneous presence of fresh and aged smoke layers. These peculiar conditions occurred on 16 July 2024 at the CNR-IMAA atmospheric observatory (CIAO) in Potenza (Italy), and represent an ideal case for the evaluation of the impact of aging and transport mechanisms on both the optical and microphysical properties of biomass burning aerosol. The fresh smoke was originated by a local wildfire about 2 km from the measurement site and observed about one hour after its ignition. The other smoke layer was due to a wide wildfire occurring in Canada that, according to backward trajectory analysis, traveled for about 5–6 days before reaching the observatory. Synergetic use of lidar, ceilometer, radar, and microwave radiometer measurements revealed that particles from the local wildfire, located at about 3 km a.s.l., acted as condensation nuclei for cloud formation as a result of high humidity concentrations at this altitude range. Optical characterization of the fresh smoke layer based on Raman lidar measurements provided lidar ratio (LR) values of 46 ± 4 sr and 34 ± 3 sr, at 355 and 532 nm, respectively. The particle linear depolarization ratio (PLDR) at 532 nm was 0.067 ± 0.002, while backscatter-related Ångström exponent (AEβ) values were 1.21 ± 0.03, 1.23 ± 0.03, and 1.22 ± 0.04 in the spectral ranges of 355–532 nm, 355–1064 nm and 532–1064 nm, respectively. Microphysical inversion caused by these intensive optical parameters indicates a low contribution of black carbon (BC) and, despite their small size, particles remained outside the ultrafine range. Moreover, a combined use of CIAO remote sensing and in situ instrumentation shows that the particle properties are affected by humidity variations, thus suggesting a marked particle hygroscopic behavior. In contrast, the smoke plume from the Canadian wildfire traveled at altitudes between 6 and 8 km a.s.l., remaining unaffected by local humidity. Absorption in this case was higher, and, as observed in other aged wildfires, the LR at 532 nm was larger than that at 355 nm. Specifically, the LR at 355 nm was 55 ± 2 sr, while at 532 nm it was 82 ± 3 sr. The AEβ values were 1.77 ± 0.13 and 1.41 ± 0.07 at 355–532 nm and 532–1064 nm, respectively and the PLDR at 532 nm was 0.040 ± 0.003. Microphysical analysis suggests the presence of larger, yet much more absorbent particles. This analysis indicates that both optical and microphysical properties of smoke can vary significantly depending on its origin, persistence, and transport in the atmosphere. These factors that must be carefully incorporated into future climate models, especially considering the frequent occurrences of fire events worldwide. Full article

Date seeds, a by-product of the pitted-date industry, are often discarded as waste. This study investigated the interaction between date seed powder and starch at different concentrations (0, 1, 5, 10, and 20 g/25 g composite) and temperatures (40 °C and 70 °C). The results revealed that the hygroscopicity of date seed powder (9.94 g/100 g) was lower than starch (13.39 g/100 g), and its water absorption (75.8%) was also lower than starch (88.3%), leading to a reduced absorbance capacity in composites. However, the solubility increased with a higher date seed content due to its greater solubility (17.8 g/L) compared to starch (1.6 g/L). A morphological analysis showed rough, agglomerated particles in date seed powder, while starch had smooth, spherical shapes. This study also found that the composites formed larger particles at 40 °C and porous structures at 70 °C. Crystallinity decreased from 41.6% to 12.8% (40 °C) and from 24.0% to 11.3% (70 °C). A thermal analysis revealed three endothermic peaks (glass transitions and solid melting), with an additional oil-melting peak in high-seed samples. FTIR spectra showed changes in peak intensities and locations upon seed incorporation. Overall, these findings revealed that, the incorporation of date seed powder–starch composites into bakery formulations offers a promising strategy for developing fiber-enriched products, positioning them as functional ingredients with added nutritional value. Full article

Hypothesis: Structural optimization of crosslinkers within a reactive glycerol-based hexagonal lyotropic liquid crystal (HLLC) system is proposed to enhance the interfacial stability of hexagonal mesophases and improve the hexagonal structure retention during polymerization. This targeted modification is anticipated to significantly improve the water filtration efficiency of HLLC-templated nanofiltration. Experiments: The effect of crosslinkers on the interfacial stability of glycerol-based hexagonal mesophases was studied by evaluating their concentration accommodation within the mesophases using ¹³C solid NMR, FTIR and SAXS. Findings: A hydrophilic crosslinker consisting of ten ethylene glycol units shows less interference with the interfacial stability of hexagonal mesophases, therefore contributing to a higher concentration accommodation compared to the one with three ethylene glycol units. This long-chain crosslinker, despite having a low content of reactive groups, effectively connects the cylinders and better retains the hexagonal structures during polymerization than the hydrophobic crosslinker with shorter ethylene glycol units but a higher content of reactive groups. The retained hexagonal nanofiltration membranes show a remarkable pure water permeability of 40 L m⁻² h⁻¹ bar⁻¹ µm, resulting from the strong hygroscopic effect of glycerol and the crumpled surface of membranes due to the flexible nature of the system plasticized by glycerol. Full article

Wood is a green and renewable bio-based building material, but its hygroscopicity affects its dimensional stability, limiting its use in construction. Chemical modification can improve its properties, yet its effectiveness depends on wood permeability and traditional modifiers. This study first used a deep eutectic solvent (DES) to boost the permeability of North American alder wood. Then, methyl trimethoxysilane was impregnated under supercritical carbon dioxide (SCI), pressure (PI), vacuum (VI), and atmospheric pressure (AI) conditions. DES treatment damaged the cell structure, increasing wood permeability. Silane was deposited and polymerized in the cell lumen, chemically bonding with cell-wall components, filling walls and pits, and thickening walls. The VI group had the highest absolute density (0.59 g/cm³, +36.6%) and the lowest moisture absorption (4.4%, −33.3%). The AI group had the highest ASE (25%). The PI group showed the highest surface hardness (RL, 2592 N) and a water contact angle of 131.9°, much higher than natural wood. Overall, the VI group had the best performance. Silane reacts with cellulose, hemicellulose, and lignin in wood via hydrolysis and hydroxyl bonding, forming stable bonds that enhance the treated wood’s hydrophobicity, dimensional stability, and surface hardness. Full article

In response to the growing impact of the climate crisis, many countries are accelerating efforts to develop sustainable and carbon-free energy solutions. This has led to increasing interest in advanced energy storage and conversion technologies, particularly the development of high-temperature molten salt energy systems. Among these, chloride salt-based molten salt systems, which offer excellent thermal properties such as high thermal conductivity, low melting points, and favorable chemical stability, are emerging as strong candidates for thermal energy storage and heat-transfer applications. This study focuses on deriving key thermophysical properties essential for selecting suitable molten salt heat-transfer fluids by examining their eutectic points and thermal stability with respect to various salt compositions. Three chloride mixtures—NaCl-MgCl₂, NaCl-KCl-MgCl₂, and NaCl-KCl-ZnCl₂—were evaluated for potential use in high-temperature molten salt energy systems. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed to measure the melting points and thermal stability of molten salts with various compositions near their eutectic regions. Experimental results were compared with predicted eutectic points to assess the thermal performance of each salt mixture. The findings indicate that the NaCl-KCl-MgCl₂ mixture exhibits the most promising characteristics, including a low melting point below 400 °C and superior thermal stability, making it highly suitable as a heat-transfer fluid in high-temperature molten salt energy systems. In contrast, NaCl-KCl-ZnCl₂ was found unsuitable for such applications due to its high hygroscopicity and poor thermal stability. This study provides essential data for selecting optimal molten salt compositions for the efficient and reliable operation of high-temperature molten salt energy systems. Full article

The crystallization of soluble salts is one of the most significant agents of deterioration affecting porous building materials in historical architecture. This process not only compromises the physical integrity of the materials but also results in considerable aesthetic, structural, and economic consequences. Soluble salts involved in these processes may originate from geogenic sources—including soil leachate, marine aerosols, and the natural weathering of parent rocks—or from anthropogenic factors such as air pollution, wastewater infiltration, and the use of incompatible restoration materials. This study examines the role of capillary rise as a primary mechanism responsible for the vertical migration of saline solutions from the soil profile into historic masonry structures, especially those constructed with calcareous stones. It describes how water retained or sustained within the soil matrix ascends via capillarity, carrying dissolved salts that eventually crystallize within the pore network of the stone. This phenomenon leads to a variety of damage types, ranging from superficial staining and efflorescence to more severe forms such as subflorescence, microfracturing, and progressive mass loss. By adopting a multidisciplinary approach that integrates concepts and methods from soil physics, hydrology, petrophysics, and conservation science, this paper examines the mechanisms that govern saline water movement, salt precipitation patterns, and their cumulative effects on stone durability. It highlights the influence of key variables such as soil texture and structure, matric potential, hydraulic conductivity, climatic conditions, and stone porosity on the severity and progression of deterioration. This paper also addresses regional considerations by focusing on the context of Spain, which holds one of the highest concentrations of World Heritage Sites globally and where many monuments are constructed from vulnerable calcareous materials such as fossiliferous calcarenites and marly limestones. Special attention is given to the types of salts most commonly encountered in Spanish soils—particularly chlorides and sulfates—and their thermodynamic behavior under fluctuating environmental conditions. Ultimately, this study underscores the pressing need for integrated, preventive conservation strategies. These include the implementation of drainage systems, capillary barriers, and the use of compatible materials in restoration, as well as the application of non-destructive diagnostic techniques such as electrical resistivity tomography and hyperspectral imaging. Understanding the interplay between soil moisture dynamics, salt crystallization, and material degradation is essential for safeguarding the cultural and structural value of historic buildings in the face of ongoing environmental challenges and climate variability. Full article

Herein, a novel super-hygroscopic material, steam-exploded modified corn stalk pith (SE-CSP), was developed from corn stalk pith (CSP) via the steam explosion (SE) method, and its hygroscopic properties and mechanisms were evaluated. The results confirmed that SE effectively removed lignin and hemicellulose, disrupted the thin cell walls of natural CSP, and formed an aligned porous structure with capillary channels. SE changed the bonding distribution and surface morphology, and enhanced the crystallinity and thermal stability of CSP. The equilibrium hygroscopic percentage of SE-CSP (62.50%) was higher than that of CSP (44.01%) at 25 °C and 80% relative humidity (RH), indicating significantly greater hygroscopicity. The hygroscopic process of SE-CSP followed a Type III isotherm and fitted the Guggenheim–Anderson–de Boer (GAB), Peleg, and pseudo-first-order kinetic models. This process exhibited multi-layer adsorption with enthalpy-driven, exothermic behavior, primarily through physical adsorption involving hydrogen bonds and van der Waals forces. This work offered a new approach for advancing sorption dehumidification technology. Full article