Search Results (19)

Salt tolerance is a key factor limiting coastal vegetation restoration. In backshore areas, foliage is frequently exposed to salt mist and wave splash, which severely constrains plant survival and restoration outcomes. While root salt tolerance under short-term stress has been widely studied, foliar salt tolerance remains poorly understood. Here, using a self-developed experimental apparatus, we investigated the salt tolerance mechanisms of the coastal shrub Volkameria inermis through a long-term (159-day) foliar salt stress experiment (0–3.0% NaCl), followed by a 64-day recovery period. Field suitability was also evaluated at different coastal locations in Quanzhou Bay, Fujian Province. The results show that: (1) trait plasticity (e.g., leaf thickening), resource redirection (e.g., reduced growth rate, and new bud emergence in unstressed parts), and strong recovery capacity together enhance V. inermis adaptation to long-term foliar salt stress; (2) V. inermis exhibits adaptability to salinity ≤2.0% and survival under 3.0% despite severe injury; (3) besides osmotic adjustment, proline accumulation helps alleviate oxidative damage; and (4) field data demonstrated that leaf thickness and leaf water content were significantly associated with distance from the sea and elevation, thereby validating the salt-adaptation strategies observed under controlled conditions. This study provides a novel methodological framework and practical insights for selecting salt-tolerant species in coastal restoration. Full article

The conservation of tuff- and coral rock-built architectural heritage structures (AHS) is challenging because access to original tuff and coral rock has become difficult and severely limited due to urbanization, land reclamation, the depletion of stone quarries, anti-mining and anti-quarrying legislation. An emerging approach to address this issue is to create compatible “replacement” rocks via geopolymerization, a process that is more sustainable and greener than the use of conventional cement and concrete. To explore the potential of geopolymers for AHS conservation strategies, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were implemented; 103 eligible articles were identified and classified into geopolymers for AHS (34 articles), tuff-built AHS (60 articles), and coral rock-built AHS (9 articles). Tuff substrates in AHSs appear in a variety of colors (yellowish-brown, grayish-cream, reddish-brown, pale greenish-gray and pink hues), densities (1.0–2.5 g/m³), and compressive strengths (3–100 MPa). Meanwhile, coral rock substrates in AHSs appear in whitish-cream color and are coarse-pored (1–5 MPa), fine-grained (8–15 MPa), and calcarenite (50–60 MPa). In terms of geopolymer formulation, metakaolin was reported as the most popular main precursor or admixture, while NaOH and Na₂SiO₃ were used simultaneously as alkaline activators. Aggregates used in geopolymer formulations depended on local availability, including quartz sand, river sand, crushed stones, carbonate stones, volcanic rock, volcanic sand, tuff, brick, ceramic tiles, and waste materials. Aesthetics, chemical composition, physical attributes, and mechanical properties have been identified as key criteria to ensure geopolymer compatibility for AHS conservation application. To date, geopolymers have been applied for AHS conservation as repair mortars, consolidants (i.e., grout and adhesives), and masonry strengthening (i.e., fiber-reinforced mortar). Finally, geopolymers formulated for AHS conservation have similar durability as the original substrate based on accelerated aging tests (i.e., salt mist, wet-dry, and freeze–thaw) and long-term outdoor exposure experiments. Full article

Juniper formations are valuable habitats for fauna and flora and play an important role in protecting the ecosystem, where they grow, from erosion and degradation. Juniper habitats are included in the European Directive 92/43. Juniperus phoenicea is of great ecological importance in Mediterranean areas, as it is often among the only species that can survive under extremely unfavorable conditions. Along with other species, it forms the habitat 2250* “Coastal dunes with Juniperus spp.” Habitat 2250* is a priority habitat, and today, it is under threat due to several factors such as coastal erosion, forest fires, etc. Therefore, the main objective of this study is to investigate the factors that affect the rooting of J. phoenicea shoot cuttings collected from plants growing in their natural habitat. Specifically, the effects of the cutting collection season and the different concentrations (0, 3, 6, and 12 g·L⁻¹) of the plant growth regulator K-IBA (indole-3-butyric acid potassium salt) on the rooting of J. phoenicea shoot cuttings in two propagation systems (mist and fog) were investigated. The shoot cuttings of J. phoenicea rooted in high percentages reaching more than 90%. The factors studied played an important role, and significant differences in the rooting ability of cuttings were found, as well as in the number and length of roots. For the optimal results, cuttings should be collected in winter and treated with 6 g·L⁻¹ K-IBA under a mist system or in summer with 3 g·L⁻¹ K-IBA under a fog system. The results of the present study can be used to make up a basic step for conservation and restoration efforts and for sustainable exploitation strategies for this valuable phytogenetic resource. Full article

Ti-bearing blast furnace slag (TBS), a byproduct of vanadium–titanium magnetite smelting, serves as an important secondary resource for titanium recovery. However, the complex mineralogical composition and finely dispersed nature of titanium in TBS present significant challenges for efficient extraction. This review systematically examines four major titanium extraction routes: hydrometallurgical leaching, pyrometallurgical smelting, molten salt electrolysis, and selective precipitation, focusing on their limitations and recent improvements. For instance, conventional acid leaching suffers from acid mist release, a colloidal formation that hinders titanium recovery, and waste acid pollution. The adoption of concentrated sulfuric acid roasting activation effectively suppresses acid mist emission and prevents colloidal generation. Pyrometallurgical approaches are hampered by high energy consumption and substantial carbon emissions, which can be alleviated through the use of gaseous reductants to enhance reaction efficiency and reduce environmental impact. Molten electrolysis faces issues such as polarization and undesirable dendritic deposition; these are mitigated by employing liquid metal cathodes integrated with vacuum distillation to achieve high-purity titanium products. Selective precipitation struggles with strict crystallization conditions and low separation efficiency, though advanced techniques like supergravity separation show improved extraction performance. We propose an integrated technical strategy termed “Online conditioning driven by waste heat-mineral phase reconstruction-directional crystallization-optimized liberation.” This approach utilizes the inherent waste heat of slag combined with electromagnetic stirring to enhance homogeneity and promote efficient titanium recovery, offering a sustainable and scalable solution for industrial TBS treatment. Full article

Extinguishing methanol fires poses significant challenges due to methanol’s high toxicity, polarity, and fluidity. While conventional fire suppressants, such as alcohol-resistant firefighting foam, water mist and dry powders, can extinguish methanol fires, they fail to prevent the spread of liquid methanol, creating a risk of environmental contamination as the mixture of suppressants and methanol flows into surrounding soil and water resources. To address this issue, a novel kind of composite dry powder has been developed to effectively combat methanol pool fires. The powder can not only rapidly extinguish flames but also transform liquid methanol into gel-like substances, significantly reducing the hazards caused by the flow of harmful liquids. Laboratory experiments identify an optimal mass ratio of 0.16 between the composite powder and methanol to achieve complete flame extinction and liquid solidification. The superior performance of as-prepared composite powder could be mainly ascribed to the cooperation of metallic salts, polymers, and silica additives. Additionally, the powder is effective for extinguishing ethanol fires, making it a valuable tool for the emergency management of alcohol fires in leakage incidents. Full article

The paper presents a new approach towards forming Ce-based nanostructures using deep eutectic solvents (DESs) as new green solvents and large-scale media for the chemical and electrochemical synthesis of advanced functional surfaces and nanomaterials. Some experimental results regarding the cathodic electrodeposition of cerium-based conversion coatings onto AA7075 aluminum alloys involving different DES-based formulations are discussed. Electrolytes containing Ce(NO₃)₃·6H₂O dissolved in choline chloride-glycerine and choline chloride-urea (1:2 molar ratio) eutectic mixtures with additions of H₂O₂ have been proposed and investigated. The influence of the operating parameters, including the applied current density, process duration and temperature on the quality of the formed Ce-containing conversion layers was studied. Adherent and uniform Ce-based conversion layers containing 0.3–5 wt.%. Ce have been obtained onto Al alloy substrates. Higher values of the applied current density and longer process durations led to higher Ce content when a choline chloride-urea eutectic mixture was used. Several accelerated corrosion tests were performed to evaluate the corrosion performance, respectively: (i) continuous immersion in 0.5 M NaCl for 720 h with intermediary visual examinations, recording of (ii) potentiodynamic polarization curves and of (iii) impedance spectra at open circuit potential in 0.5 M NaCl, as well as (iv) salt mist test for 240 h. The influence of an additional post-treatment step consisting in the electrochemical deposition of a hydrophobic Ce-based layer involving ethanolic solutions of stearic acid and cerium nitrate is also considered. Different corrosion performances are discussed, taking into account the used DES-based systems and electrodeposition parameters. Full article

This contribution presents the results of research focused on changes in selected properties of organic-coated steel sheets in a corrosive environment of salt mist. The aim of this study was to characterise coated sheets and to analyse the influence of elevated temperature on changes in their selected properties. The methodology and experiments were chosen to simulate the accelerated ageing and to evaluate the surface of organic-coated steel sheets. During the research, the effect of artificial ageing due to increased temperature on changes in mechanical properties of coated sheets was monitored, which were determined by tensile testing according to STN EN 10002-1. The fracture surface of the test samples was analysed using a SEM. The following observations were made for the evaluation of coating by cross-cut tests according to EN ISO 2409. Corrosion tests were carried out by conducting salt spray corrosion tests according to EN ISO 9227. The test specimens were artificially sectioned using a laser beam. The results of the research experiments confirmed the assumption that the utilisation of the laser beam was convenient for the creation cross–cut test of the material. After the ageing test, only small significant changes in the basic mechanical properties of the tested materials were observed. It is necessary to take into account that there were changes in the appearance of the coating. The cross-cut test confirmed the results that the plastic-coated sheets could be utilised in salt corrosion environments. Full article

The aim of this research work is to study the effect of salt mist ageing on the physico-mechanical properties of two ignimbrites from the Canary Islands (Spain). Due to their insular nature and extensive coastlines, these regions are highly susceptible to atmospheric salt aerosols, which is a significant weathering agent for building materials. The ignimbrites analysed are marketed under the names “Azul Lomo Tomás de León” and “Marrón de Abades” and are widely used as building stones. Petrographic, mineralogical and chemical properties were obtained via polarisation microscopy, X-ray diffraction and X-ray fluorescence. The samples were subjected to 60 cycles of a salt mist environment, following relevant European standards. Scanning electron microscopy images of the specimens were analysed along with physical properties, including apparent density, open porosity, water absorption, colourimetry and ultrasound propagation velocity, initially and after every 20 cycles, allowing us to assess their evolution during the ageing test. Mechanical properties were evaluated using uniaxial compressive strength and flexural strength under concentrated load tests on two groups of specimens: one unaged and the other subjected to 60 ageing cycles. With the exception of apparent density, the other properties show a decrease between 5% and 30%. However, open porosity increases and is one of the properties most affected by the ageing test. Full article

Salvia officinalis, commonly known as sage, is highly valued for its medicinal and ornamental properties. In the present work, 12 native sage populations of north-west Greece were evaluated for eight ornamental traits. Populations from the locations of Aristi, Kefalovryso and Igoumenitsa were selected as the best performing and for their preservation and availability in the market, their asexual propagation was investigated by (a) shoot cutting and (b) in vitro techniques. Propagation by cuttings was investigated during the four seasons. Aristi exhibited the highest rooting (65%) in spring with a well-developed root system (4.7 root number and 5.0 cm length) by applying 0.5 g·L⁻¹ Indole-3-butyric acid, potassium salt (K-IBA), established on perlite under a fog system. However, the rooting performance of Aristi spring cuttings was not affected by different substrates of peat:perlite (0:1, 1:1, 1:2 v/v) or rooting systems (mist, fog) tested. Furthermore, the in vitro propagation of the selected sage populations was investigated using shoot tips as explants. After successful disinfection, the effect of Murashige and Skoog (MS) medium in ten different combinations of Indole-3-acetic acid (IAA), 6-Benzylaminopurine (BAP) and Thidiazuron (TDZ) were tested on shoot multiplication. Aristi presented the highest number of newly formed shoots on MS9 (0.1 mg·L⁻¹ IAA and 0.8 mg·L⁻¹ TDZ) and MS5 (0.1 mg·L⁻¹ IAA and 0.8 mg·L⁻¹ BAP) (3.35 and 3.21 new shoots/explant, respectively) with the highest shoot length (2.23 cm and 3.2 cm) and unexpected spontaneous root formation (64%) at MS5. The rooting ability of Aristi microshoots was further investigated in order to enhance their response. Of the three rooting variants tested, optimal rooting formation (100%) was observed on 0.9 mg·L⁻¹ IAA (R3) combined with successful acclimatization (100%). Aristi exceeded the other populations in both the tested propagation systems, thus holding a strong potential for its introduction in the market as a competitive ornamental variety. Full article

Salinity is one the most recurrent abiotic stresses worldwide and severely affects crop productivity in arid and semiarid environments. This research analyzed several plant growth regulators that could mitigate the effects of salinity on olive plants (Olea europaea L. cultivar Picual). Mist-rooted cuttings were grown in a growth chamber and pretreated with gibberellic acid (GA₃), indole-3-acetic acid (IAA), salicylic acid (SA), and Kinetin by foliar spraying twice a week for three weeks. At the end of the pretreatment, the plants were exposed to 100 mM and 200 mM sodium chloride (NaCl) for six weeks. The results showed that plants pretreated with the plant growth regulators significantly increased their biomass under saline conditions. In addition, IAA and SA restricted the transport of sodium (Na⁺) ions from roots to leaves and improved the leaf potassium (K⁺)/Na⁺ ratio. IAA and SA favored proline, fructose, and mannitol accumulation in leaves at 100 mM and 200 mM NaCl, as did glucose at 200 mM NaCl. Salicylic acid and IAA increased pigments (chlorophylls and carotenoids) and polyamines accumulation under saline conditions. The findings of this study suggest that pretreatments with IAA and SA may be a highly effective way of increasing salt tolerance in olive plantlets. Full article

Epoxy and epoxide composites have a wide range of outdoor applications wherein they are affected by ageing. In this study, epoxy casting plates and epoxy-based composite rods for use in overhead conductors were prepared. A concurrent investigation concerning the ageing of epoxy resins and their carbon fibre composites was carried out via artificially accelerated experiments under hygrothermal and salt mist conditions. The moisture penetration along the depth, water absorption, appearance, hardness, density of the epoxy resins, and variation patterns of the impact strength and tensile strength of the epoxy-based composites were investigated. The ageing mechanisms were explored using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Both ageing modes had essentially similar influences on the properties of the resins and their composites; moreover, they did not significantly affect the chemical structure and microstructure of the epoxy resin, with the physical adsorption of water primarily observed during the ageing process. The moisture absorption behaviour of the epoxy obeyed Fick’s law. Although the water penetration rate in the salt mist ageing mode was slightly higher than that in the hygrothermal ageing mode during the early ageing stage, it was essentially the same during the later stage. The final moisture absorption rate at saturation was approximately 1.1% under both modes. The flexural strengths and impact strengths of the composites in both ageing modes followed a similar trend. They decreased gradually with the ageing time and then stabilized at almost the same value. The flexural strength was reduced from 803 MPa to 760 MPa and the impact strength from 383 J/m² to 310 J/m², indicating a decrease of approximately 5.4% and 19%, respectively. The absorbed water during the ageing process caused micro-cracks at the interface between the fibres and resin, weakening the interfacial strength and reducing the mechanical properties of the composites. Full article

To predict the behavior of gas-cleaning filters during real-world operation, it is essential to understand their response to ambient conditions. The temporary presence of water droplets in gas-cleaning filtration systems due to fog, spray rain, or condensation, as examples of irregular events, has an impact on the filters’ operating performance, especially when soluble particles are present. In this work, surface filters were loaded with mixtures of water-soluble salt particles and insoluble glass spheres. These were, subsequently, exposed to water mist and dried by a particle-free gas stream. A novel approach to analyze the drainage of solution on filters with soluble filter cakes is presented, which allows the detection of solubles on the clean gas side of the filter. As a result, this work, for the first time, presents a sighting of the penetration of soluble filter cake material through gas-cleaning filters. Furthermore, filter performance, in terms of differential pressure and fractional separation efficiency, was determined and a characteristic differential pressure evolution for hydrophilic filters during exposure to water mist was also identified. The fractional separation efficiency of gas-cleaning filters decreases due to exposure to water mist. The findings are supported by scanning electron microscopy (SEM) images, energy-dispersive X-ray (EDX), and X-ray microtomography (µ-CT analysis) images. Full article

This work reports a new finding on the effect of dissolved salts, in water-air mists, on spray heat removal efficiencies from a metallic surface under steady state conditions. The experimental system is based on a calorimeter that measures heat flux removed by water-air mist sprays from 8 mm diameter × 2.5 mm thickness platinum samples heated by electromagnetic induction. During steady-state experiments, a solid-state controller equilibrates automatically the rate of heat generation with the rate of heat removal to reach a constant temperature. Equilibrium temperatures for stepwise T rising include 200 to 1200 °C in steps of 100 °C and then stepwise T that is lowered to 200 °C. The new finding is that, when using soft water-air mist and a high-water impingement density, a lack of temperature control during stepwise T increases was observed when stepping from 200 to 300 °C. This lack of temperature control is associated with a high heat flux and is attributed to the stabilization of the single-phase convection regime when T rising from 200 to 300 °C. Temperature stabilization was again possible only at wall temperatures ${\mathrm{T}}_{\mathrm{w}}\ge 600$°C, at which single-phase convection was not stable. In contrast, when using a hard water-air mist under the same fluid flow conditions, all temperatures were readily reached. This is attributed to the transition from single-phase convection to nucleate boiling regime when T increased from 200 to 300 °C. This transition leads to a decrease in heat flux due to a reduction in the contact area between liquid and the wall surface. Finally, the corresponding boiling curves at high wall temperatures show the importance of heat radiation from the wall to understand the effect of salts during the stable vapor film regime. Full article

Rosmarinus officinalis L. belongs to the Lamiaceae family and is cultivated worldwide due to its diverse uses as an ornamental evergreen shrub in gardening, as well as a food seasoning and a natural medicine. The present research was conducted to study the morphological traits of seven wild-grown rosemary populations in Greece, as well as the propagation of two selected populations with the most desirable ornamental characteristics, by the use of shoot cuttings and in vitro cultures. From the study of the morphological traits of the seven populations, those with interesting features were grown in the areas of Amaliada and Piperia and, thus, were chosen for studying their propagation. Rooting of the shoot cuttings was carried out during the four seasons of the year, using potassium salt Indole-3-butyric acid (K-IBA) at concentrations of 0.5 and 1 g·L⁻¹, in various substrates under the intermittent mist or fog system. It was found that the shoot cuttings rooted easily in all four seasons, but there were better results for the population of ‘Piperia’ in autumn, with 1 g·L⁻¹ K-IBA (80%), and ‘Amaliada’ in spring, with 0.5 g·L⁻¹ K-IBA (82.5%), while higher rooting percentages were achieved in the fog system, on a substrate consisting of perlite and peat, in a ratio of 2:1 (85%). For the in vitro cultures, shoot tips excised from the two selected populations were successfully disinfested by pre-soaking in an antioxidant solution and then, by sterilizing them in 0.6% (w/v) NaOCl, followed by transferring them onto a Murashige and Skoog (MS) nutrient medium. ‘Amaliada’ cultures proved to be the most productive population (2.1 shoots per explant), with the highest shoot formation frequency (91.6%), when cultivated on the MS nutrient medium without plant growth regulators. For ‘Piperia’ cultures, the highest shoot formation frequency (66.6%) was achieved on the MS nutrient medium supplemented with 0.25 or 0.5 mg·L⁻¹ 6-Benzyloaminopurine (BAP) and 0.1 mg·L⁻¹ Indole-3-acetic acid (IAA). Spontaneous root formation frequency was noticed on the MS nutrient medium, containing 0.5 mg·L⁻¹ BAP and 0.1 mg·L⁻¹ IAA, for both ‘Amaliada’ and ‘Piperia’ cultures (50% and 41.6%, respectively) in a single stage, with root lengths of 7.1 and 5.3 cm, respectively. Rosemary plantlets, with roots formed in vitro after transplanting them in soilless substrate, were acclimatized adequately in the greenhouse environment (~70%). Full article

The article presents the results of the research on the influence of heat treatment conditions on corrosion resistance of newly developed HSLA-type (High Strength Low Alloy) steel in selected corrosive environments. Laboratory tests were carried out with using a salt spray chamber, enabling the continuous spraying of brine mist (5% NaCl) during 96 h under high humidity conditions. Additionally, as part of corrosion experiments, tests were carried out using the gravimetric method, in which the intensity of corrosive processes was measured by the linear corrosion rate. The research conducted revealed that the best corrosion resistance was noted for steel with a high-temperature tempered martensite microstructure. Investigated 0.28C–1.4Mn–0.3Si–0.26Cr steel with Nb, Ti, and V microadditions can be used in offshore drilling constructions and production platforms exposed to salts present in sea water, chlorides, sulfates, carbonates, and bromides, among others. Full article