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Due to their extraordinary qualities, including fire resistance, excellent crashworthiness, low thermal conductivity, permeability, non-toxicity, and reduced density, cellular materials have found extensive use in various engineering applications. This study uses a finite element analysis (FEA) to model the dynamic compressive behaviour of agglomerated cork to ascertain how its material density and stress relaxation behaviour are related. Adding the Mullins effect into the constitutive modelling of impact tests, its rebound phase and subsequent second impact were further examined and simulated. Quasi-static and dynamic compression tests were used to evaluate the mechanical properties of three distinct agglomerated cork composite samples to feed the numerical model. According to the results, agglomerated cork has a significant capacity for elastic rebound, especially under dynamic strain rates, with minimal permanent deformation. For instance, the minimum value of its bounce-back energy is 11.8% of the initial kinetic energy, and its maximum permanent plastic deformation is less than 10%. The material's model simulation adequately depicts the agglomerated cork's response to initial and follow-up impacts by accurately reproducing the material's dynamic compressive behaviour. In terms of innovation, this work stands out since it tackles the rebounding phenomena, which was not previously investigated in this group's prior publication, either numerically or experimentally. Thus, this group has expanded the research on cork materials' attributes. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of different closures used in second fermentation on the aromatic fraction of sparkling wine. Six types of closures (cork stoppers and screw caps) and 94 months of aging in a bottle were investigated. Headspace solid-phase microextraction (HS-SPME) and thermal desorption (TD) procedures coupled to gas chromatography-mass spectrometry (GCMSMS) analysis were applied. The vectors containing the relative abundance of the volatile compounds are compositional vectors. The statistical analysis of compositional data requires specific techniques that differ from standard techniques. Overall, 101 volatile compounds were identified. HS-SPME extracted the highest percentage of esters, ketones and other compounds, while TD was a useful tool for the obtention of alcohol, acid, ether and alkane compounds. Esters were the most abundant family of compounds. Compositional data analysis, which was applied to study the impact of different closures used in bottle aging after second fermentation on the volatile composition of sparkling wine, concluded that there are differences in the relative abundance of certain volatile compounds between cork stoppers and screw-cap closures. Overall, the most abundant part in screw-cap closures was ethyl hexanoate, and it was ethyl octanoate in cork stoppers. Also, the proportional amount of dimethylamine was higher in screw-cap closures than cork stoppers relative to the entire sample. [ABSTRACT FROM AUTHOR]

Recently, more and more researchers have begun to consider using waste bark fractions to produce value-added biochemicals and materials, as well as for energy production. Extraction is often the first operation in biomass biorefineries. Here we obtained hydroethanolic extracts from waste cork and phloem fractions of Quercus cerris bark and analyzed them to determine their antioxidant, antimicrobial, and nitric oxide (NO) production inhibition properties and their hepatotoxicity. The antioxidant properties were investigated by ex vivo TBARSs as well as OxHLIA antioxidant assays, the antibacterial properties against Gram-positive and Gram-negative bacteria isolated from food and clinical sources, and antifungal properties against Aspergillus brasiliensis and A. fumigatus. The NO production inhibition activity was assessed in a lipopolysaccharide (LPS)-stimulated murine macrophage (RAW 264.7) cell line, and antiproliferative activities were determined against five different cell lines, including lung (NCI-H460), gastric (AGS), breast (MCF7), and colon (CaCo2) tumor cell lines, as well as a non-tumor cell line (PLP2). The hydroethanolic maceration of waste cork and phloem yielded 4.4% and 2.4% extracts, respectively. Gallic acid glucosides, phenolic acids, and ellagic acid were identified in both extracts. The waste cork and phloem extracts showed antioxidant, antimicrobial, antifungal, and antiproliferative properties but also showed hepatotoxicity in the case of waste cork. Both bark fractions varied in terms of their bioactivity, with waste cork extracts showing, in general, higher bioactivity than phloem extracts [ABSTRACT FROM AUTHOR]

Combining machine vision and deep learning, optical detection technology can achieve intelligent inspection. To address the issues of low efficiency and poor consistency in the quality classification of cork discs used for making badminton heads, research on optimizing the YOLOv5 image-processing algorithm was conducted and applied to cork disc quality detection. Real-time images of cork discs were captured using industrial cameras, and a dataset was independently constructed. A GAN-based defect synthesis algorithm was employed to resolve the lack of defect samples. An attention mechanism was embedded in the YOLOv5 backbone network to enhance feature representation. The number of anchors in the YOLOv5 detection layer was reduced to address similar sample sizes, a center-matching strategy was designed to balance positive samples, and a shortest-distance label assignment algorithm was developed to eliminate ambiguities, improving accuracy and reducing postprocessing complexity. Detection results were integrated into quality classification. Experiments on the NVIDIA RTX3080 GPU demonstrated that the optimized algorithm improved the original YOLOv5 F1 score by 2.4% and mF1 score by 9.0%, achieving a quality classification F1 score of 95.1%, a processing speed of 178.5 FPS, and an mAP of 81.5%. Comparative experiments showed that the improved algorithm achieved the best detection accuracy on the cork disc dataset while maintaining high processing speed. [ABSTRACT FROM AUTHOR]

Metallum Fire-Resistant paint, denoted as MFR henceforth, represents a cutting-edge insulating material with dual functionality as a fireproof solution, presenting substantial advantages in the realm of construction applications. This exposition derives its primary insights from the scholarly contributions documented in publications. The focal point of these investigations includes the assessment of fire hazards associated with polyethylene materials in building structures and the enhancement of mortars in high-temperature environments in tunnels. The purpose of this study is to evaluate the effectiveness of a modified cork-based coating (MFR) compared to traditional coatings in terms of corrosion protection, fire resistance, and thermal insulation properties in construction applications. This evaluation focuses on quantifying the efficacy of MFR by examining key properties, such as adhesion, the reduced thickness required for fire protection, thermal conductivity reduction, and corrosion resistance under extreme environmental conditions. MFR is highly effective in fire prevention for buildings and tunnels, withstanding temperatures over 1000 °C while maintaining structural integrity. A unique aspect of MFR is its use of cork shavings, a typically underutilized byproduct from wine-bottle-stopper production. This innovative not only amplifies MFR's fire-resistant attributes, but also introduces sustainability and judicious resource utilization into its manufacturing processes. [ABSTRACT FROM AUTHOR]

Recent seismic events have prompted research into innovative and sustainable materials for strengthening and repairing obsolete and vulnerable buildings. These earthquakes have exposed the high seismic vulnerability of existing reinforced concrete (RC) buildings, particularly in secondary structural elements like infill walls. In addition to structural issues, these buildings often face significant energy deficiencies, such as thermal bridges, due to inadequate insulation. Traditionally, structural and energy improvements for residential buildings are addressed separately with different methods and protocols. This preliminary study is part of a broader research initiative at the University of Reggio Calabria (Italy), aiming to design an innovative fiber-reinforced plaster using natural, sustainable, and locally produced materials to enhance the energy and structural performance of existing wall infills. The study investigates two plaster matrices made of natural hydraulic lime and silica sand, with 15% and 30% cork granules added. Mechanical and thermophysical tests on multiple specimens were conducted to evaluate their suitability for seismic and energy retrofitting of infill walls. Results indicate that adding cork reduces mechanical strength by approximately 42% at a 30% cork content without compromising its use in seismic retrofitting. Thermophysical tests show improved thermal performance with a higher cork content. These findings suggest that the lime–cork mixture at 30% is effective, offering excellent ductility and serving as a promising alternative to traditional cementitious plaster systems. The next experimental phase will test matrices with varying percentages of gorse fiber. [ABSTRACT FROM AUTHOR]

Developing new products that satisfy performance and durability expectations while also addressing environmental concerns is possible through the reuse of residues produced by industrial processes, aiming to fulfill the principles of circular economy. In this study, we improved the performance of a carbon paste sensor by incorporating untreated (RC) and regranulated/thermally treated (RGC) cork, which are considered biomass residues from the cork industry. We explored the electroanalytical behavior of paracetamol in sulfuric acid solutions using cyclic voltammetry and differential pulse techniques. The cork-modified carbon paste sensors showed greater sensitivity towards paracetamol. Both modified sensors allowed for an excellent resolution in distinguishing the voltammetric responses of paracetamol in sulfuric acid, showing for both an increase in peak currents compared to the unmodified carbon paste electrode. The quantification of paracetamol without interference has proved to be a feasible operation for the RC- and RGC-modified carbon paste sensors; notably, the first showed the most favorable limits of detection (LD = 2.4112 µM) and quantification (LQ = 8.0373 µM) for paracetamol in the sulfuric acid solution, performing significantly better than the second (LD = 10.355 µM, and LQ = 34.518 µM). Finally, the practical utility of the proposed sensors was assessed by analyzing paracetamol in pharmaceutical samples, obtaining satisfactory results that were in line with those obtainable using high-performance liquid chromatography. [ABSTRACT FROM AUTHOR]

Cork, the outermost tissue of bark, plays an important role in protecting trees from the surrounding environment and is used for various purposes, including flooring and insulation materials for buildings. This study focused on the amount and distribution of hydrophobic substances such as suberin and lignin in cork, as well as moisture conditions, to understand the mechanical properties of Cerasus jamasakura cork. Strips of cork were subjected to tensile tests after exposure to various moisture conditions (water-saturated, air-dried and oven-dried), and also after the desuberinisation and delignification of specimens. Cork with a high moisture content showed significant strain to the tensile load, whereas oven-dried specimens showed little toughness. The increased toughness of cork at higher moisture contents was due to the continued elongation in the plastic region, especially in the inner cork. The fibre length of the highly deformed cork differed significantly before and after the tensile test. Tensile tests of cork after desuberinisation and delignification indicated that the removal of suberin caused an earlier reduction in tensile properties than the removal of lignin. The presence of suberin in cork, distributed mainly in the inner cork, is believed to affect the tensile properties of cork. [ABSTRACT FROM AUTHOR]

The children's toy market is increasingly dominated by products that rely heavily on visual appeal. This article presents the development of 'bumpi', a cork toy specially developed for young children who experience visual impairments or blindness. Research was conducted about these children's needs and the existing assistive products for them in the market. This research revealed that they often face developmental challenges, including delays in achieving key milestones such as crawling and walking, which happens because blind and visually impaired children are less confident to moving and exploring. A significant gap in the market for toys and assistive devices for blind young children was identified. Bumpi aims to fill such a gap. It is designed to stimulate and foster the earlier development of motor skills in children between one and five years old, leading to greater independence. This toy enhances sensory experiences through touch and sound to stimulate children's urge to move. The toy set includes a puzzle-like mat, a toy cart that follows a predefined path, building blocks for constructing a ramp, and sensory balls that emit sounds when they move. Agglomerated cork, chosen for its unique properties such as lightness, durability and its hypoallergenic nature, is the primary material used. Furthermore, it is not only safe and comfortable for children to handle but also offers great stimulation to their senses. In addition, this is a sustainable material that offers several benefits for the toy industry. [ABSTRACT FROM AUTHOR]

The present work analyzes the effect of releasing physically bound water from hydrogel, cork, perlite, and ceramsite on materials exposed to microwave radiation and subsequently investigates possible changes in the physical properties of these materials (water absorption and thermal conductivity coefficient). The release of physically bound water from individual materials has potential practical applications in materials engineering, for example, in the internal curing of concrete, where individual aggregates could, under the influence of microwave radiation, release water into the structure of the concrete and thus further cure it. Experimental analysis was carried out with samples of the above-mentioned materials, which were first weighed and then immersed in water for 24 h. Then, they were weighed again and exposed to microwave radiation. After exposure, the samples were weighed again, left immersed in water for 24 h, and weighed again. The focus of the study was on the ability of the aggregates to release water due to microwave radiation and on the changes in the properties (water absorption, thermal conductivity coefficient) of these materials when exposed to microwave radiation. The samples were further monitored by digital microscopy for possible changes in the surface layer of the materials. The hydrogels show the highest water absorption (1000%) and the fastest water release (45 min to complete desiccation). After the release of water due to microwave radiation, their ability to absorb water is maintained. Of interest, however, is that in the case of almost complete removal of water from the soaked hydrogel, the original powdered state of the hydrogel is not obtained, but the outcome has rather a solid structure. In the case of cork, the water absorption depends on the fraction of the material. [ABSTRACT FROM AUTHOR]

The bioactive properties of underutilized corks such as Quercus cerris cork and planted Quercus suber cork in the Eastern Mediterranean are not well-known but are crucial in developing lignocellulosic biorefineries. To assess their biological potential, hydroethanolic cork extracts of Quercus cerris and Quercus suber were analyzed for phenolic composition, antioxidant, antiproliferative, antimicrobial activities, and hepatoxicity, as well as NO-production inhibition. Here, we show that a mild hydroethanolic extraction of Q. cerris and Q. suber corks yielded 3% phenolic extracts. The phenolic composition was similar in both cork extracts, with phenolic acids and ellagitannins as the primary compounds. The bioactivity of hydroethanolic cork extracts from Q. cerris surpassed that of Q. suber and showed effectiveness against all cancer cell lines tested. This first comprehensive study on the bioactivities of different corks involves detailed characterizations of phenolic compounds of cork extracts using UPLC-DAD-ESI/MSn, evaluations of the antioxidant properties with TBARS and OxHLIA methods, evaluation of antiproliferative activity against gastric (AGS), lung (NCI-H460), colon (CaCo2), and breast cancer (MCF7) cell lines, as well as evaluations of hepatotoxicity and NO-production inhibition. The findings from this study will help bolster the potential of using underutilized cork-rich barks as a valuable resource in bark-based biorefineries. [ABSTRACT FROM AUTHOR]

The beekeeping sector is increasingly focused on creating optimal and natural environments for honeybees to reduce dependence on external factors, especially given progressively hotter summers. Improving hive thermal conditions can enhance bee wellbeing and production. While pinewood hives are predominant, some have started using insulating materials like polystyrene. However, many synthetic materials, despite their excellent insulation properties, are incompatible with organic food production, requiring alternative solutions. This study compares the thermal insulation properties of various natural materials, including white and black agglomerated cork, wood fibres, and rock mineral wool. These materials are potentially compatible with organic food production. Additionally, the research evaluates cost-effective sensor networks to monitor bioclimatic variables in real time. Lab tests using a Langstroth-type hive with a controlled heat source were conducted, monitoring temperature and humidity inside and outside the hive. The results revealed that all selected materials provided similar thermal insulation, superior to a hive without insulation. This finding suggests that using natural materials can enhance hive thermal comfort (i.e., the material's ability to maintain a stable internal temperature), thereby improving honeybee wellbeing and productivity in a manner compatible with organic food production. [ABSTRACT FROM AUTHOR]

Even though the design of vibration isolators is well-established for many engineering applications, their efficiency in wide and multiple frequency ranges is still a challenge. In these cases, the use of Phononic-Based Vibration Isolators (PBVIs) may be advantageous as they present different Attenuation Regions (ARs) in which the elastic waves are strongly attenuated. Therefore, the present paper is devoted to the experimental evaluation, in terms of force transmissibility, of different types of supporting devices tested on a load mass and a motor of a Hermetic Compressor (HC). Those devices are the original Helical Coil Spring (HS) that equips the HC, the PBVI, and the Combined Structure (CS) which is composed of a PBVI combined in series with the HS. Results evidentiate the capability of the CSs to isolate vibrations, where the PBVI contributes with its ARs, thus operating as a "filter" in specific frequency ranges, while the HSs maintain the flexibility of the CSs, which is advantageous for impact-loads and/or transient-case scenarios. Hence, the capability, relevance and impact that these PBVIs present for force transmissibility reduction applications is highlighted here, which should capture the attention of and motivate the industry, e.g., producers of isolation systems, since it has wide-ranging engineering applications. [ABSTRACT FROM AUTHOR]

The recycling of waste materials is a way of limiting over-consumption and optimizing the value of resources. Within the framework of a circular economy, this can be applied to post-consumer plastic wastes, but also to biobased by-products. Hence, this work deals with the design of composite materials by combining recycled high-density polyethylene (HDPE) and polypropylene (PP) coming from bottle caps and virgin cork of insufficient quality for cork stoppers. Different fractions (0, 5, 10, 15, and 20 wt%) of virgin cork were incorporated into recycled polymers (HDPEr and PPr). These composites were prepared without a coupling agent or fire retardant. The morphology and mechanical properties of the different conditionings were studied and compared. The thermal decomposition and the fire behavior of the composites were also investigated. Microscopy revealed the poor adhesion between the cork particles and polymer matrices. However, this limited interaction affected only the tensile strength of the PPr composites, while that of the HDPEr composites remained almost constant. The addition of cork was shown to reduce the time to ignition, but also to promote charring and reduce the heat released during the composite's combustion. The feasibility of composites based on cork and HDPEr/PPr waste opens the way for their reuse. [ABSTRACT FROM AUTHOR]

Agglomerated cork is a natural cork that has gone through a process of crushing and pressing using heat and binders. One of its applications is thermal insulator in construction. The design of these materials is becoming an essential part of building. The raw materials currently used to make insulators consume a large amount of energy, which has created the need to increase the use of renewable and ecological resources such as plant fibers to reduce the environmental problems generated. The objective of this study was to determine the different properties of experimental particleboard panels made from cork and Canary Island date palms without using any binder at minimum energy consumption. The produced cork–palm boards (density of 850 kg/m3, reached a MOR 8.83 N/mm2, MOE 794.5 N/mm2, and IB 0.38 N/mm2) are higher values than the traditional cork particleboards with UF made from cork. The thermal conductivity values obtained 0.069 to 0.096 W/m·K are higher than cork boards with UF. Ecological boards that can be used as rigid thermal insulators in the construction industry have been achieved to improve the mechanical properties of the traditional agglomerated cork. [ABSTRACT FROM AUTHOR]

This study investigates the feasibility of using a composite material comprising slate reinforced with cork sheets for architectural purposes like facades and wall coverings. The research involves the comprehensive characterisation of both slate and cork materials along with the evaluation of the silicone adhesive used in their bonding process, specifically Sikasil® HT from SIKA®. It was found that both slate and cork exhibited low wettability, which was enhanced through cold plasma treatment. Subsequently, a composite sandwich structure was fabricated and subjected to impact testing in a drop tower, along with fire resistance evaluations. The fire tests revealed that when subjected to a flame of 900 °C for 15 min, the slate alone heated rapidly, reaching 500 °C within 3 min on the side opposite to the flame. However, the sandwich structure reached 260 °C on the cork side (opposite to the flame) at 7.5 min, maintaining this temperature until the deterioration or detachment of the cork between 11 and 12 min. This provided insulation and delayed ignition. The sandwich structure maintained its fire resistance due to the insulating properties of cork and the superior thermal resistance of silicone compared to other adhesives up to 260 °C. Overall, the results suggest the potential suitability of this sandwich structure for architectural applications. Its favourable adhesion properties and acceptable fire resistance indicate that it could serve as a viable alternative for construction materials in architectural contexts. [ABSTRACT FROM AUTHOR]

Introducing fillers into polymeric materials is one of the methods of modifying the properties or reducing the costs of polymeric materials. Thanks to their use, it is possible to obtain new materials with interesting mechanical and chemical properties. Some features are often improved among the new materials obtained, while others deteriorate. In this work, an attempt was made to obtain a polymer composite based on PLA filled with cork flour in amounts of 5%, 10%, 15%, 20% and 30% by weight. The processing and sample preparation process using injection molding technology was assessed and the basic mechanical properties were assessed. The research shows that it is possible to obtain PLA products with a cork filler without the mixing process on an extruder, but only by using an injection molding machine and appropriately selecting the parameters of the technological process. Tests of mechanical properties showed deterioration of parameters, but not to such an extent that the obtained composites were disqualified from use in products that are not subject to heavy mechanical loads. The undoubted advantage of the obtained materials is maintaining their so-called "green" character and thus the ability to biodegrade. [ABSTRACT FROM AUTHOR]

This pilot investigation identifies the influence that changing the process variables of curing pressure, curing temperature, and mix ratio of a polyurethane/agglomerated cork matrix has on the mechanical properties of energy absorption, Young's modulus of elasticity, and spring stiffness in safety helmets intended for micro-transport riders. The results are compared to expanded polystyrene, a material commonly used in micro-transport helmets. Mechanical testing of the various samples found that, over the range tested, curing pressure had no effect on any of the mechanical properties, while increasing amounts of resin caused a stiffer structure, and increasing curing temperature led to increased energy absorption. Consistent with the elastic modulus findings, all polyurethane/agglomerated cork test samples demonstrated higher median levels of spring stiffness, ranging from 7.1% to 61.9% greater than those found for expanded polystyrene. The sample mixed at a 1.5:1 binder/cork ratio and cured at 40 °C displayed the closest spring stiffness to EPS. While the mechanical properties of the eco-friendly polyurethane/agglomerated cork matrix did not match those of expanded polystyrene, the difference in performance found in this study is promising. Further investigation into process variables could characterise this more ecologically based matrix with equivalent energy-absorbing and structural characteristics, making it equivalent to currently used expanded polystyrene and suitable for use in micro-transport helmets. [ABSTRACT FROM AUTHOR]

The development of sustainable materials from the valorization of waste is a good alternative to reducing the negative environmental impact of plastic packaging. The objectives of this study were to develop and characterize pectin-based composite films incorporated with cork or cork with either coffee grounds or walnut shells, as well as to test the films' genotoxicity, antioxidant properties, and biodegradation capacity in soil and seawater. The addition of cork, coffee grounds, or walnut shells modified the films' characteristics. The results showed that those films were thicker (0.487 ± 0.014 mm to 0.572 ± 0.014 mm), more opaque (around 100%), darker (L* = 25.30 ± 0.78 to 33.93 ± 0.84), and had a higher total phenolic content (3.17 ± 0.01 mg GA/g to 4.24 ± 0.02 mg GA/g). On the other hand, the films incorporated only with cork showed higher values of elongation at break (32.24 ± 1.88% to 36.30 ± 3.25%) but lower tensile strength (0.91 ± 0.19 MPa to 1.09 ± 0.08 MPa). All the films presented more heterogeneous and rougher microstructures than the pectin film. This study also revealed that the developed films do not contain DNA-reactive substances and that they are biodegradable in soil and seawater. These positive properties could subsequently make the developed films an interesting eco-friendly food packaging solution that contributes to the valorization of organic waste and by-products, thus promoting the circular economy and reducing the environmental impact of plastic materials. [ABSTRACT FROM AUTHOR]

Cork composites are byproducts from wine stopper production, resulting from the agglomeration of cork granules with a thermoset resin. The resulting compound is a versatile and durable material with numerous industrial applications. Due to its unique properties, such as low-density, high-strength, excellent energy absorption, and good thermal and acoustic insulators, cork composites find room for application in demanding industries such as automotive, construction, and aerospace. However, agglomerated cork typically has a polyurethane matrix derived from petrochemical sources. This study focuses on developing eco-friendly porous polyurethane biocomposites manufactured with the used cooking oil polyol modified with cork. Since cork and polyurethane foam are typically used for impact shock absorption, the manufactured samples were subjected to impact loading. The assessment of crashworthiness is performed through 100 J impact tests. A finite element numerical model was developed to simulate the compression of these new composites under impact, and the model validation was performed. The highest specific absorbed energy was obtained for petrochemical polyol composites with the 3% addition of natural or modified cork. The research conducted in this study showcased the feasibility of substituting certain petrochemical components used for the synthesis of the polyurethane matrix with ecological waste vegetable oil components. [ABSTRACT FROM AUTHOR]

In the wine bottling process, thermoplastics are commonly used to manufacture the crown of cork stoppers. The production of agglomerated cork stoppers generates a type of waste called cork powder (CoP) in large volumes with known properties but which are still underutilized. At present, although there are many agrocomposites available with additives such as natural fibers or solid residues from agricultural products, there are no studies describing the formation of these agrocomposites from petroleum-derived synthetic plastics combined with cork dust as a reinforcement for the polymeric matrix. The present study describes a novel agrocomposite, which has been obtained by mixing polypropylene-type materials, as they are some of the most widely used and versatile thermoplastics, with cork dust, which is a waste product obtained from the cork industry. The composite is obtained directly, without the need for grafting, adhesive polymers, or coupling agents. A superior mechanical performance compared to the unprocessed polymer was highlighted in the test results, thus evidencing the reinforcing function played by the waste in the polymer matrix. Therefore, this novel agrocomposite could be a promising alternative to replace some petroleum-derived synthetic plastics, which are currently experiencing high demand. The use of this new agrocomposite is well aligned with sustainability strategies, the principles of the circular economy, and oriented towards the fulfilment of the Sustainable Development Goals required by the European Union, considering that it contributes (a) to recycling agricultural waste that would otherwise be difficult to recover and valorize; (b) to the reduction in the CO2 footprint; and (c) to promoting the use of high-quality secondary raw materials. [ABSTRACT FROM AUTHOR]

Quercus suber is considered a sustainable tree mainly due to its outer layer (cork) capacity to regenerate after each harvesting cycle. Cork bark is explored for several application; however, its industrial transformation generates a significant amount of waste. Recently, cork by-products have been studied as a supplier of bioactive ingredients. This work aimed to explore whether near infrared spectroscopy (NIRS), a non-destructive analysis, can be employed as a screening device for selecting cork by-products with higher potential for bioactives extraction. A total of 29 samples of cork extracts were analysed regarding their qualitative composition. Partial least squares (PLS) models were developed for quantification purposes, and R2P and RER values of 0.65 and above 4, respectively, were obtained. Discrimination models, performed through PLS-DA, yielded around 80% correct predictions, revealing that four out of five of samples were correctly discriminated, thus revealing that NIR can be successfully applied for screening purposes. [ABSTRACT FROM AUTHOR]

Cork spot-like physiological disorder (CSPD) is a newly identified issue in 'Kurenainoyume' apples, yet its mechanism remains unclear. To investigate CSPD, we conducted morphological observations on 'Kurenainoyume' apples with and without pre-harvest fruit-bagging treatment using light-impermeable paper bags. Non-bagged fruit developed CSPD in mid-August, while no CSPD symptoms were observed in bagged fruit. The bagging treatment significantly reduced the proportion of opened lenticels, with only 17.9% in bagged fruit compared to 52.0% in non-bagged fruits. In non-bagged fruit, CSPD spots tended to increase from the lenticels, growing in size during fruit development. The cuticular thickness and cross-sectional area of fresh cells in CSPD spots were approximately 16 µm and 1600 µm², respectively. Healthy non-bagged fruit reached these values around 100 to 115 days after full bloom from mid- to late August. Microscopic and computerized tomography scanning observations revealed that many CSPD spots developed at the tips of vascular bundles. Therefore, CSPD initiation between opened lenticels and vascular bundle tips may be influenced by water stress, which is potentially caused by water loss, leading to cell death and the formation of CSPD spots. [ABSTRACT FROM AUTHOR]

Cork is a natural and renewable material extracted from the cork oak Quercus suber L. (1) Background: The cellular structure and chemical composition of the plant wall give cork its physical and mechanical properties. Chemically, the composition of cork is principally dominated by the presence of suberin as the main structural cell wall component and affected by its close association with other components. The usual chemical analysis of cork has been partially adapted from wood and other lignocellulosic analytical methods and it is a method with extensive procedures. This study aims to (i) find quicker and more sustainable methods for testing the cork chemical composition, (ii) conduct extraction tests using alternative techniques, (iii) optimize alternative methodologies, and (iv) validate the proposed sustainable methodologies. (2) Methods: Microwave-assisted extraction (MAE) and accelerated solvent extraction (ASE) are explored as alternative systems to the traditional method. The percentages of the extractives obtained via MAE are lower than the percentages obtained by means of the classical composition. (3) Results: However, the percentages of suberin are very similar in both methods: 46.39% in the case of the classical composition and 45.11% in the case of microwave-assisted extraction. No significant differences are observed between the content of the extractives in the dichloromethane, ethanol, and water obtained via ASE and the results obtained with the classical methodology. (4) Conclusions: MAE and ASE are faster methods; they use less solvents and provide more reproducible results than the classical chemical composition methodology. These data pave the way for novel sustainable alternatives relative to the studies of the chemical composition of cork. [ABSTRACT FROM AUTHOR]

Sandwich composites are often used as primary load-bearing structures in various industries like aviation, wind, and marine due to their high strength-to-weight and stiffness-to-weight ratios, but they are vulnerable to damage from Low-velocity-impact (LVI) events like dropped tools, hail, and birdstrikes. This often manifests in the form of Facesheet-Core-Debonding (FCD) and is often termed Barely-Visible-Impact-Damage (BVID), which is difficult to detect and can considerably reduce mechanical properties. In general, a balsa core sandwich is especially vulnerable to FCD under LVI as it has poorer adhesion than synthetic core materials. A cork core sandwich does show promise in absorbing LVI with low permanent indentation depth. This paper also reviews surface treatment/modification as a means of improving the adhesion of composite core and fiber materials: key concepts involved, a comparison of surface free energies of various materials, and research literature on surface modification of cork, glass, and carbon fibers. Since both balsa and cork have a relatively low surface free energy compared to other materials, this paper concludes that it may be possible to use surface modification techniques to boost adhesion and thus FCD on balsa or cork sandwich composites under LVI, which has not been covered by existing research literature. [ABSTRACT FROM AUTHOR]

Bark is a heterogeneous solid material comprising mainly of phloem and cork fractions. These fractions differ in chemical composition and anatomical structure, and value-added activated carbons produced from these fractions have different surface properties. Low-temperature pyrolysis was shown to be a promising method for producing activated carbon precursors from bark fractions at higher yields than conventional slow pyrolysis. Here, we produced mesoporous activated carbons (ACs) from cork and phloem fractions of Quercus cerris bark by low-temperature pyrolysis followed by steam activation at 900 °C. The results showed steam-activation of biochars from Q. cerris bark fractions yielded ACs with acceptable surface properties. The ACs contained 9.9% and 23.3% ash content, and specific surface areas of 201 m2 g−1 and 512 m2 g−1 for cork and phloem fractions, respectively. Calcium was the principal inorganic component of ACs, followed by potassium, silicon, and iron. Surface functional groups of bark fractions and biochars were lost during steam activation, as evidenced by FT-IR spectroscopy. The burnout temperatures of cork and phloem ACs were 726 °C and 736 °C, respectively. The ACs showed a high methylene blue and methyl orange adsorption capacity, with the removal of 80% and 90% of methylene blue and 58% and 68% of methyl orange after 48 h for cork and phloem ACs, respectively. [ABSTRACT FROM AUTHOR]

In this study, the efficiency of mechanically alloyed Fe80Si10B10 in degrading basic red 46 azo dye is investigated. Moreover, the influences of different parameters, such as pH and time, on the elimination of the aromatic derivatives obtained as by-products of the fracture of the azo group are also analyzed. After beginning the reduction to the normal conditions of pH (4.6) and temperature, the experimental findings showed a discoloration of 97.87% after 20 min. The structure and morphology of the nanocrystalline Fe80Si10B10 powder were characterized by SEM and XRD before and after use in the degradation process. The XRD patterns of the Fe–Si–B powder after redox reaction suggest that the valent zero Fe of the alloy is the reducing agent. Powdered cork was then used as a biosorbent for the removal of the by-products generated, resulting in increasing removal percentages from pH 7 (26%) to pH 9 (62%) and a contact time of 120 min. The FTIR spectrum of the cork after adsorption shows a shift of the bands, confirming the interaction with the aromatic amines. The present findings show that metallic powders and natural cork perform well together in removing azo dye solutions and their degradation products. [ABSTRACT FROM AUTHOR]

Cork is a sustainable natural material widely used as a wine stopper. However, some other uses, such as wall coverings, flooring, bags and shoes, face UV damage. To mitigate this issue, we explored the deposition of TiO2 and ZnO thin films via magnetron sputtering on glass and cork substrates. Both films displayed uniformity and the lack of any discernible cracks or voids, remained transparent in the visible region, and offered UV protection. Thus, TiO2 and ZnO blocked UV light with a wavelength of up to 310 nm (Eg = 4 eV) and 370 nm (Eg = 3.3 eV), respectively. Exposure tests, under a sun simulator lamp, revealed that the uncoated cork showed noticeable color changes, even when located under a glass substrate. The TiO2 coating did not prevent cork discoloration, while ZnO prevented it. This study highlights ZnO thin films as a durable solution to safeguard cork materials from UV damage and extend their usability. [ABSTRACT FROM AUTHOR]

The general practice of rainfall-runoff model development towards physically based and spatially explicit representations of hydrological processes is data-intensive and computationally expensive. Physically based models such as the Soil Water Assessment tool (SWAT) demand spatio-temporal data and expert knowledge. Also, the difficulty and complexity is compounded in the smaller watershed due to data constraint and models' inability to generalize hydrologic processes. Data-driven models can bridge this gap with their mathematical formulation. Long Short-Term Memory (LSTM) is a data-driven model with Recurrent Neural Network (RNN) architecture, which is better suited to solve time series problems. Studies have shown that LSTM models have competitive performance in watershed hydrology studies. In this study, a comparative analysis of SWAT and LSTM models in the Cork Brook watershed shows that results from LSTM were competitive to SWAT in flow prediction with NSE of 0.6 against 0.63, respectively, given the limited availability of data. LSTM models do not overestimate the high flows like SWAT. However, both these models struggle with low values estimation. Although interpretability, explainability, and use of models across different datasets or events outside of the training data may be challenging, LSTM models are robust and efficient. [ABSTRACT FROM AUTHOR]

This paper presents the technological advancement of using friction powders to increase the absorption of acoustic liners used in the reduction of tonal noise generated by aero-engines or for other applications related to Helmholtz resonators used in noise absorption of low frequencies. The experimental research was conducted during the European project ARTEM (2017–2022), and after. This concept was inspired by the discovery made by several historians of narrow neck bottles filled with ash in the old Christian churches. These artifacts were made with the purpose of absorbing low frequency noises. Based on this creative idea, the present authors proposed a new method of noise absorption capabilities of acoustic liners filled with various types and quantities of natural and artificial powders. Considering the positive results the ARTEM project offered, COMOTI continued testing this concept by using even finer cork powders manufactured with a new technology. Measurements in Kundt tubes showed that noise absorption increased significantly in broadband for low frequencies (over 0.9 at high frequencies and 0.6 at low frequencies, 500 Hz). Some of the researched powders can be used in the field of bladed machines to reduce the aerodynamic noise of an aircraft or in the automotive industry where the reduction of low frequency noises is necessary. [ABSTRACT FROM AUTHOR]

Evaluating the efficiency of surface treatments is a problem of paramount importance for the cork stopper industry. Generically, these treatments create coatings that aim to enhance the impermeability and lubrification of cork stoppers. Yet, current methods of surface analysis are typically time-consuming, destructive, have poor representativity or rely on indirect approaches. In this work, the use of a laser-induced breakdown spectroscopy (LIBS) imaging solution is explored for evaluating the presence of coating along the cylindrical surface and in depth. To test it, several cork stoppers with different shaped areas of untreated surface were analyzed by LIBS, making a rectangular grid of spots with multiple shots per spot, to try to identify the correspondent shape. Results show that this technique can detect the untreated area along with other features, such as leakage and holes, allowing for a high success rate of identification and for its performance at different depths, paving the way for future industry-grade quality control solutions with more complex surface analysis. [ABSTRACT FROM AUTHOR]

Insulation materials are fundamental for decreasing energy losses and guaranteeing thermal and acoustic comfort in buildings, which may significantly contribute to decreasing the energy consumption related with poor thermal building conditions. These insulation materials should have a low susceptibility to biological degradation agents to decrease the risks of degradation of other construction materials, as well as decrease possible health risks related with the development of noxious biological degradation agents regarding indoor air quality, for example, or decrease possible structural risks posed by those agents. The present study aimed at evaluating the susceptibility of several insulation materials to mold growth and subterranean termites' attack. Insulation materials, including expanded polystyrene (EPS), mineral wool (MW), and expanded cork agglomerate (ICB), were tested against mold development, using maritime pine as a control. Three types of inoculations were made: (1) natural indoor inoculation; (2) artificial inoculation using Aspergillus niger and Penicillium funiculosum; and (3) artificial inoculation using Aureobasidium pullulans. The susceptibility of the insulation materials referred to, plus wood/glass fiber (WGF), was evaluated for two subterranean termite species: Reticulitermes grassei and Reticulitermes flavipes. The expanded cork agglomerate showed a higher susceptibility to molds than the other insulation materials tested. The remaining materials revealed a good performance, showing no growth or traces of growth of molds. All the materials tested showed susceptibility to subterranean termites, with both species being able to cross them to obtain access to the wood. However, wood/glass fiber showed a negative effect, which translated into lower survival rates and attack degrees of the wood. Some tested materials showed a good resistance to the development of biological degradation agents, namely an organic material (coconut fiber), a composite of organic and inorganic materials (WGF), and an inorganic material (EPS). These results indicate that it is possible to pursue the development of innovative and effective insulation materials with a low susceptibility to biological degradation agents, regardless of their organic or inorganic origin. [ABSTRACT FROM AUTHOR]

Two classes of thermal protection systems composed of a carbon-fibre-reinforced (CFRP) layer and an ablative material layer joined with a thermo-resistant ceramic adhesive were developed. The two classes differ in the composition of the ablative material reinforcing compound. In the first class, the ablative material is based on micronic-sized cork granules, and in the second class, the ablative material is reinforced with carbonic felt. For both classes of thermal protection systems, the reinforcement material was impregnated in simple phenolic resin, and nanometric additive, consisting of silicon carbide nanoparticles added in two different weight contents (1 and 2% by weight) relative to the resin. The thermal conductivity for the ablative materials in the thermal protection systems structure was determined. A test facility using oxy-butane flame was developed through which the thermal protection systems developed were tested at extreme temperatures, to simulate some thermal conditions in space applications. The materials were characterised from a morphostructural point of view using optical and scanning electron microscopy after thermal testing. The TPS composed of the carbon-felt-based ablative layer showed improved behaviour compared to the cork-based ablative ones in terms of the temperature increase rate during thermal conductivity testing, mass loss, as well as morphostructural appearance and material erosion after oxy-butane testing. The nSiC-based samples in both sets of TPSs showed improved behaviour compared to the un-filled ones, considering the temperature increase, mass loss, and morphostructure of the eroded material. [ABSTRACT FROM AUTHOR]

While extensive efforts have been made over the past two decades to understand how cork becomes contaminated by 2,4,6-trichloroanisole (TCA), the nature of its bond to cork remains unclear. A deeper understanding of this interaction is crucial in designing processes to effectively remove TCA from cork stoppers. This study presents an investigation into the thermal desorption of TCA from cork under vacuum conditions. To facilitate detection by a quadrupole mass spectrometer, samples were artificially contaminated with sufficient TCA. A calibration system was developed to determine the absolute rate of TCA released from the cork. Desorption spectra revealed two peaks at 80 °C and 170 °C. Despite the known variability of cork, repeated measurements demonstrated reasonable repeatability. The low-temperature peak decreased with time and after preheating the sample to 50 °C. It is proposed that the high-temperature peak corresponds to TCA bonded to the cork material. Experiments with naturally contaminated cork stoppers revealed a significant reduction in the amount of releasable TCA following a vacuum-heating process. This study provides an insightful discussion on the adsorption of TCA on cork and proposes an estimate for the adsorption energy. Furthermore, it discloses a process capable of removing TCA from natural cork stoppers. [ABSTRACT FROM AUTHOR]

Quercus suber L. is an evergreen cork oak tree that can produce cork, one of the most important valuable natural bioresources in Portugal, with a high impact for the bioeconomy. Given its socio-economic relevance and the upcoming biotic and abiotic threats cork oak faces, it is of extreme importance that genetic conservation of its genetic variability occurs so that cork oaks can adapt to new conditions. This work represents a review of the current knowledge on Quercus suber genetic resources, focusing on the existing genetic variability and the strategies for its conservation. Furthermore, we highlight genetic knowledge on tolerance and response to abiotic and biotic stresses and cork quality, which are useful for further studies on stress response pathways and mechanisms and improvement regarding stress tolerance. [ABSTRACT FROM AUTHOR]

The effect of the addition of Fe0 and Fe3+ on the formation of expanded clay aggregates was studied using iron-free kaolin as an aluminosilicates source. Likewise, the incorporation of cork powder as a source of organic carbon and Na2CO3 as a flux in the mixtures was investigated in order to assess its effect in combination with the iron phases. An experimental protocol, statistically supported by a mixture experiments/design of experiments approach, was applied to model and optimize the bloating index, density, absorption capacity, and mechanical strength. The process of expansion and pore generation and the associated decrease in density required the addition of iron, such that the optimum mixtures of these properties presented between 25 and 40 wt.% of Fe0 or Fe3+, as well as the incorporation of 3.5–5 wt.% of organic carbon. The addition of Fe3+ produced a greater volumetric expansion (max. 53%) than Fe0 (max. 8%), suggesting that the formation of the FeO leading to this phenomenon would require reducing and oxidizing conditions in the former and the latter, respectively. The experimental and model-estimated results are in good agreement, especially in the aggregates containing Fe0. This reinforces the application of statistical methods for future investigations. [ABSTRACT FROM AUTHOR]

Among the material extrusion technologies of additive manufacturing, fused granular fabrication is playing a bigger role in the industry. The increase in the size of printers demands extrusion systems with higher deposition rates that facilitate printing larger parts in shorter times with a need for cost reduction. This cost reduction in fused granular fabrication systems is due to the utilisation of pellets as the material source for the prints, such as pellets that are the most common way of distributing polymeric materials in industry and do not need the usual previous transformation into filaments. Most of the polymers in the industry can be found in the shape of pellets, so the opportunities for developing new materials beside the traditional filaments found in the market are expanding. In this research, a novel composite material has been developed based on the blending of commercial thermoplastic polyurethane (TPU) and cork particles obtained from industrial waste at different concentrations. These materials have been processed at a laboratory scale, and their mechanical, thermal and rheological properties have been studied. Despite a 53.52% reduction in the maximum stress on the x-axis, an 81.82% decrease in the values obtained with specimens oriented on the z-axis and a shortage in the deformation values, the results reveal a remarkable weight reduction leading to 21.31% when compared to the TPU of the blends,. These results may open a path to further explore these blends and find suitable applications in industry as proposed. [ABSTRACT FROM AUTHOR]

Waste-grade cork samples of Quercus cerris were subjected to maceration extraction using 7 different solvents, including pure water (I), pure acetone (II), 75% aqueous ethanol (III), 75% aqueous methanol (IV), 75% aqueous acetone (V), 50% aqueous acetone (VI), and 25% aqueous acetone (VII). The extract yields, extract compositions, as well as antioxidant and antimicrobial activities of the extracts were analyzed. The results showed that maceration extraction was highly efficient, particularly with binary solvents resulting in up to 6% extract yield and up to 488 mg GAE/g extract total phenolic content. The extracts exhibited a variable antioxidant activity determined by DPPH and FRAP methods as well as antimicrobial activity against gram-positive bacteria and fungus determined by agar diffusion test. The CIELAB color parameters of extracts were correlated with maceration time, and the correlation was highest with pure water extracts. The FT-IR spectra of acetone-extracted cork revealed six key markers of phenolic compounds with the presence of peaks at approximately 2920 cm−1, 2850 cm−1, 1609 cm−1, 1517 cm−1, 1277 cm−1, and 1114 cm−1. The overall results suggest that the maceration of waste cork in binary solvents and pure acetone are green alternatives to conventional Soxhlet extraction for the production of polar extracts. [ABSTRACT FROM AUTHOR]

When bottled wine is opened, a completely different scenario occurs that can accelerate the oxidation of the product. This is called the secondary shelf life (SSL), which is generally shorter and less predictable than the primary shelf life (PSL). In this context, the research aim was to evaluate the changes that occur in two types of red wine during two tests to evaluate the secondary shelf life as a function of the packaging systems. The variation of Total SO2 and Free SO2 and the other chemical parameters (polyphenols, anthocyanins, proanthocyanidins, color, and volatile acidity) were used to assess the oxidation rate of the packaging samples after opening during the SSL. In both tests and for the two types of stored red wine, the polymeric cap showed the best results. The other types of closure (screw cap, natural cork, crow cap, and Tetra Brik) showed a negative trend and a reduced SSL for both red wines. Finally, the sensory results confirmed that with the polymeric cap, the SSL increases considerably compared to other capping systems. These results may be due to the technical characteristics of polymeric materials, which tend to vary slightly in shape after repeated usage. [ABSTRACT FROM AUTHOR]

Cork-based adsorbents have been gathering interest from the research community since the 1990s. A first review was published on this topic in 2012. Still, in the last decade, novel activated carbons and biochars, in multiple applications, have been produced using cork as a raw material. This review presents these novel insights into the properties of cork, in its various forms, and how they relate to adsorption capacity. Details on new preparation methodologies and respective characteristics of cork-based activated carbons and biochars are thoroughly compared, and patterns are identified. Finally, the adsorption capacity of these materials in experimental conditions is reviewed for different compounds: heavy metals, organics, and gaseous pollutants. This review provides a complete picture of the kind and quality of different cork forms, their relative economic value, and how their conversion into activated carbons and biochars can contribute to a more circular economy by producing adsorbents that aid in the reduction of multiple pollution types. [ABSTRACT FROM AUTHOR]

Cork spot is a common physiological disorder in pear fruits, which has been found in some pear cultivars. Mineral nutrition imbalance in fruit is regarded as the principal influence factor for disorder incidence, with some ongoing confusion and controversy. In our research, we explored the cork spot characteristics in Japanese pear 'Akizuki' (Pyrus pyrifolia Nakai), adopted metabolome and mineral content analysis for healthy and disordered fruits, and made a correlation analysis of mineral and metabolites. Cork spots are mainly distributed on the outer flesh beneath the fruit peel. In cork spotted tissues, superoxide (SOD) and peroxidase (POD) activities, as well as malondialdehyde (MDA) content, increased. A total of 1024 known metabolites were identified from all the samples and more changes in metabolism were detected between normal and cork spotted flesh tissues. Correlation analysis displayed that Ca, especially the Mg/Ca in fruits, could be used to predict whether an orchard will develop cork spot disorder; Mg and B were associated with the appearance of symptoms, and the contents of Zn, Fe, and Mg, as well as Mg/B and Zn/B, might be strongly tied to the formation of cork spots in pears. This research provides insights into the occurrence of pear cork spot disorder and clarifies the role of minerals. [ABSTRACT FROM AUTHOR]

The water ingress plays an important role in building materials' degradation. The use of lightweight aggregates is interesting in terms of sustainability, because they reduce the density of cement-based materials, among other advantages. The development and use of new lightweight aggregates, such as cork granulates, is a current research topic. In the present work, water ingress performance of sustainable mortars which combined expanded and natural cork aggregates and cements with slag, fly ash and limestone has been studied. Mortars produced with sand and expanded clay were also prepared. Bulk density, water absorption, drying capacity and gel and capillary pores were studied. Tests were carried out at 28 days and 1 year. A good behavior has been generally observed when an addition was incorporated to the binder, especially slag or fly ash. Regarding the new non-standardized lightweight cork aggregates, mortars with natural cork showed lower water absorption and lower volume of permeable pore space in the long term than mortars with expanded cork. At one year, natural cork mortars had an adequate water absorption performance compared to those with expanded clay, which may be due to the high volume of small capillary pores (100 nm–1 µm) in natural cork mortars. [ABSTRACT FROM AUTHOR]

The increasing popularity of additive manufacturing technologies in the prototyping and building industry requires the application of novel, improved composite materials. In this paper, we propose the use of a novel 3D printing cement-based composite material with natural, granulated cork, and additional reinforcement using a continuous polyethylene interlayer net combined with polypropylene fibre reinforcement. Our assessment of different physical and mechanical properties of the used materials during the 3D printing process and after curing verified the applicability of the new composite. The composite exhibited orthotropic properties, and the compressive toughness in the direction of layer stacking was lower than that perpendicular to it, by 29.8% without net reinforcement, 42.6% with net reinforcement, and 42.9% with net reinforcement and an additional freeze–thaw test. The use of the polymer net as a continuous reinforcement led to decreased compressive toughness, lowering it on average by 38.5% for the stacking direction and 23.8% perpendicular to the stacking direction. However, the net reinforcement additionally lowered slumping and elephant's foot effects. Moreover, the net reinforcement added residual strength, which allowed for the continuous use of the composite material after the failure of the brittle material. Data obtained during the process can be used for further development and improvement of 3D-printable building materials. [ABSTRACT FROM AUTHOR]

Massive propagation of cork oak (Quercus suber) individuals tolerant to Phytophthora cinnamomi (Pc) is probably the most important challenge for cork production. Screening for resistance to Pc of ca. 200 seedlings obtained from a single cork oak tree that has survived the epidemic was performed by soil infestation. Twenty months after Pc inoculation, 33 seedlings survived from Pc infection and the four most vigorous seedlings were selected. The plants were forced to produce new shoots under controlled climatic conditions, and the new shoots were used to establish the plants in vitro by axillary budding. High axillary shoot proliferation rates were achieved by culturing the new shoots on Lloyd and McCown (WPM) medium, followed by subculturing for 2 weeks on 0.22 µM benzyladenine (BA) and for 2 weeks further on 0.04 µM BA. Addition of 20 µM silver thiosulphate (STS) increased the proliferation rates and improved the appearance and development of shoots. Rooting rates of 80–100% were obtained by culturing the shoots for 24 or 48 h on Gresshoff and Doy medium with ⅓ macronutrients plus 122.5 µM indole-3-butyric acid and subsequent transfer to root expression medium containing 20 µM STS. The results of this study optimize the micropropagation of a relevant and recalcitrant tree species in forestry. [ABSTRACT FROM AUTHOR]

Background: Nowadays, as a result of globalization, markets are more competitive, and customers are more demanding. To respond to these challenges, organizations must develop mechanisms for continuous improvement in order to eliminate waste and increase the efficiency and effectiveness of processes. Thus, the present study carried out at an industrial unit responsible for the customization of cork stoppers for wines had as its main objectives to identify and eliminate or at least reduce waste; improve production and internal logistics flows; balance workloads; improve productivity; reduce lead time; motivate employees and promote the spirit of continuous improvement. Methods: The action-research methodology was used, whereby several cycles of data recovery and analysis, identification and implementation of opportunities for improvement, assessment and standardization were carried out. Therefore, the Total Flow Management (TFM) model was implemented, and several methods and tools were used, such as Value Stream Mapping (VSM), work measurement and 5S's. Results: Several wastes and overloads were identified, and some actions were implemented, such as workload balancing, layout changes, implementation of visual management and supermarkets. That said, it was possible to reduce lead time by 4 days, improve productivity from 26.63 ML (a thousand cork stoppers)/h to 35.75 ML/h, and promote flexibility. In addition, employees were motivated, and a culture of continuous improvement was fostered. Conclusions: This project demonstrated that it is possible to implement improvement actions, with good results, without high investments, as well as motivating employees and taking advantage of their best capabilities. Additionally, it was demonstrated that the use of TFM can be very useful in continuous improvement, with evident improvements in production and internal logistics flows. So, this project demonstrated the practical implementation of TFM regarding basic reliability, production and internal logistics flow, and the simultaneous use of several methods and tools to implement continuous improvement. Thus, significant improvements were possible on the factory floor, as well as improving employee motivation their personal development and encouraging the focus on continuous improvement. Therefore, it responds to the gap identified in the literature. [ABSTRACT FROM AUTHOR]

In this study, an analysis of the influence of extractives, suberin and lignocellulosic components on the pyrolysis decomposition and fire reaction mechanisms of a cork oak powder from Quercus suber L. is presented. The summative chemical composition of cork powder was determined. Suberin was the main component at 40% of the total weight, followed by 24% of lignin, 19% of polysaccharides and 14% of extractives. The absorbance peaks of cork and its individual components were further analyzed by means of ATR-FTIR spectrometry. Thermogravimetric analysis (TGA) showed that the removal of extractives from cork slightly increased the thermal stability between 200 °C and 300 °C and led to the formation of a more thermally stable residue at the end of the cork decomposition. Moreover, by removing suberin, a shift of the onset decomposition temperature to a lower temperature was noticed, indicating that suberin plays a major role in enhancing the thermal stability of cork. Furthermore, non-polar extractives showed the highest flammability with a peak of heat release rate (pHRR) of 365 W/g analyzed by means of micro-scale combustion calorimetry (MCC). Above 300 °C, the heat release rate (HRR) of suberin was lower than that of polysaccharides or lignin. However, below that temperature it released more flammable gases with a pHRR of 180 W/g, without significant charring ability, contrary to the mentioned components that showed lower HRR due to their prominent condensed mode of action that slowed down the mass and heat transfer processes during the combustion process. [ABSTRACT FROM AUTHOR]

We developed and tested two carbon–phenolic-based ablators for future Korean spacecraft heat shield applications. The ablators are developed with two layers: an outer recession layer, fabricated from carbon–phenolic material, and an inner insulating layer, fabricated either from cork or silica–phenolic material. The ablator specimens were tested in a 0.4 MW supersonic arc-jet plasma wind tunnel at heat flux conditions ranging from 6.25 MW/m2 to 9.4 MW/m2, with either specimen being stationary or transient. Stationary tests were conducted for 50 s each as a preliminary investigation, and the transient tests were conducted for ~110 s each to stimulate a spacecraft's atmospheric re-entry heat flux trajectory. During the tests, each specimen's internal temperatures were measured at three locations: 25 mm, 35 mm, and 45 mm from the specimen stagnation point. During the stationary tests, a two-color pyrometer was used to measure specimen stagnation-point temperatures. During the preliminary stationary tests, the silica–phenolic-insulated specimen's reaction was normal compared to the cork-insulated specimen; hence, only the silica–phenolic-insulated specimens were further subjected to the transient tests. During the transient tests, the silica–phenolic-insulated specimens were stable, and the internal temperatures were lower than 450 K (~180 °C), achieving the main objective of this study. [ABSTRACT FROM AUTHOR]

Potato tuber skin is a protective corky tissue consisting of suberized phellem cells. Smooth-skinned varieties are characterized by a clean, shiny appearance compared to the darker hue of russeted potatoes. The rough skin of russeted cultivars is a desired, genetically inherited characteristic; however, unwanted russeting of smooth-skinned cultivars often occurs under suboptimal growth conditions. The involvement of epigenetic modifiers in regulating the smooth skin russeting disorder was tested. We used smooth-skin commercial cultivars with and without the russeting disorder and three lines from a breeding population segregating for russeting. Anatomically, the russet skin showed similar characteristics, whether the cause was environmentally triggered or genetically determined. The old outer layers of the corky phellem remain attached to the newly formed phellem layers instead of being sloughed off. Global DNA methylation analysis indicated a significant reduction in the percentage of 5-methylcytosine in mature vs. immature skin and russet vs. smooth skin. This was true for both the smooth-skin commercial cultivars and the russeted lines. The expression level of selected DNA methyltransferases was reduced in accordance. DNA demethylase expression did not change between the skin types and age. Hence, the reduced DNA methylation in mature and russet skin is more likely to be achieved through passive DNA demethylation and loss of methyltransferase activity. [ABSTRACT FROM AUTHOR]

The bark fulfils several essential functions in vascular plants and yields a wealth of raw materials, but the understanding of bark structure and function strongly lags behind our knowledge with respect to other plant tissues. The recent technological advances in sampling and preparation of barks for anatomical studies, along with the establishment of an agreed bark terminology, paved the way for more bark anatomical research. Whilst datasets reveal bark's taxonomic and functional diversity in various ecosystems, a better understanding of the bark can advance the understanding of plants' physiological and environmental challenges and solutions. We propose a set of priorities for understanding and further developing bark anatomical studies, including periderm structure in woody plants, phloem phenology, methods in bark anatomy research, bark functional ecology, relationships between bark macroscopic appearance, and its microscopic structure and discuss how to achieve these ambitious goals. [ABSTRACT FROM AUTHOR]

Substrate and rhizosphere microorganisms are key factors affecting seedling growth; however, the effects of seedling substrates and rhizosphere bacteria on the growth of Quercus variabilis are not completely understood. Here, Q. variabilis seedlings were grown in substrates with and without cork flour, as follows: H substrate (charcoal soil/cork flour/perlite, 1:1:2), S substrate (cork flour/perlite, 1:1), and the control (CK) substrate (charcoal soil/perlite, 3:2). High-throughput sequencing and qPCR were used to investigate the effects of these substrates on seedling growth, physiological indices, and rhizosphere bacterial communities. Root and shoot weights of seedlings grown in H and S substrates were significantly higher than those of seedlings grown in CK. Moreover, H was conducive to chlorophyll synthesis in seedling leaves, and the transpiration rate and intercellular CO2 concentration of the leaves of seedlings grown in H were higher than those of seedlings grown in CK. The number of rhizosphere bacterial 16S rRNA copies was significantly greater in the case of seedlings grown in S than for those grown in H and CK. As well, rhizosphere bacterial richness was higher in seedlings grown in H and S than in those grown in CK. Thus, cork-flour-supplemented substrates are beneficial for seedling growth and development, seedling rhizosphere bacterial abundance and diversity, and the abundance of nitrogen and phosphorus metabolism-promoting microbial taxa. [ABSTRACT FROM AUTHOR]