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Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One challenge for 3D printing is that the mortar must flow easily through the printer nozzle, and after printing, it must develop compressive strength fast and high enough to support the layers on it. This requires an exact and difficult control of the superplasticizer (SP) dosing. Nanocrystalline cellulose (CNC) has gained significant interest as a rheological modifier of mortar by interacting with the various cement components. This research studied the potential of nanocrystalline cellulose (CNC) as a mortar aid for 3D printing and its interactions with SPs. Interactions of a CNC and SP with cement suspensions were investigated by means of monitoring the effect on cement dispersion (by monitoring the particle chord length distributions in real time) and their impact on mortar mechanical properties. Although cement dispersion was increased by both CNC and SP, only CNC prevented cement agglomeration when shearing was reduced. Furthermore, combining SP and CNC led to faster development of compressive strength and increased compressive strength up to 30% compared to mortar that had undergone a one-day curing process. [ABSTRACT FROM AUTHOR]

Considering that global awareness for sustainable development has risen to face environmental damages, different building materials have been considered from a mechanical perspective. In this sense, considering the richness of South America regarding its woods, the Guayacan and the Ecuadorian oak timbers have not been previously characterized. The present research has performed mechanical, thermal, and moisture content characterizations to acknowledge the benefits of considering these materials for the building industries. In this sense, Guayacan has been shown to have lower thermal conductivity, making it ideal for thermal insulation; the oak from Manabi showed the best compressive strength; while the oak from El Oro stands with the best tensile strength; and the oak from Loja showed the best modulus of elasticity. On the other hand, all the materials were compared by multicriteria decision methods to select the best, by using the COPRAS method driven by the objective entropy-weighted method, showing that the oak from Loja is the best choice considering the advantage that presents with the modulus of elasticity. In this sense, it is concluded that regarding the mechanical properties, there is not much difference for the compression, bending, and tensile strength; nevertheless, for the modulus of elasticity the oak from Loja stands out, making it a factor to be considered in the selection of a wood for building applications that is corroborated through multicriteria decision methods. [ABSTRACT FROM AUTHOR]

Objective: Self-sufficiency and reliance on natural materials are fundamental principles of Iranian architecture, with brick being a locally abundant material in Iran. Over time, brick buildings require retrofitting, restoration, and enhancement. To gain a deeper understanding of brick and its retrofitting, it is essential to analyze historical bricks and incorporate past experiences in brick making. This research aims to examine the technical characteristics of bricks used in the historical buildings of Kashan city across different time periods. Five brick samples from these historical structures have been selected for analysis. Method: The research employs a quantitative approach based on field studies and laboratory experiments. The experiments are categorized into three groups. The first group comprises basic tests, including density, specific gravity, moisture content, and water absorption. The second group encompasses mechanical tests, focusing on compressive and bending strength. The third category involves chemical tests conducted through X-ray Diffraction (XRD) analysis. Results: The tests revealed that the specific weight of the samples ranged from 1.6 to 2.14 grams per cubic centimeter, while water absorption varied between 9.3 and 18.5 percent. The compressive strength was found to be between 53.12 and 195.27 kg/cm², and the bending strength ranged from 11.62 to 125.83 kg/cm². The findings indicate that basic characteristics significantly influence mechanical properties. As specific weight and volume density of the samples increase, their internal pore structure diminishes, leading to reduced moisture content and lower water absorption. Furthermore, higher sample density correlates with increased compressive and bending strength. The predominant chemical composition in the samples was quartz, while the presence of gypsum contributed to decreased mechanical resistance. In contrast, higher levels of quartz, anorthite, and albite enhanced the resistance of the samples Conclusions: The physical and mechanical characteristics of brick samples remain relatively stable over time. Consequently, it appears that the resistance parameters are more influenced by the quality of the raw materials, sample density, and production methods rather than the age of the samples.

Abstract Root hair (RH) cells are important for the growth and survival of seedlings. They favor plant–microbe interactions and nutrients uptake. When invading the soil, RH cells have to penetrate a dense medium exhibiting a variety of physical properties, such as mechanical resistance, that impact the growth and survival of plants. Here we investigate the effect of the mechanical resistance of the culture medium on RH-physical and phenotypical parameters such as length, time, and speed of growth. We also analyze the impact of the environment on nuclear dynamics. We show that the RH growth rate and the nucleus speed decrease similarly as mechanical resistance increases while the time of growth of RH cells is invariable. Moreover, during RH growth, the nucleus-to-tip distance was found to decrease when the stiffness of the environment was increased. Along this line, using Latrunculin B treatment in liquid growth media, we could internally slow down RH growth to reach speeds similar to those observed in stiff solid media while the nucleus-to-tip distance was only slightly affected, supporting thus the idea of a specific effect of mechanical resistance of the environment on nucleus dynamics.

Root hair (RH) cells are important for the growth and survival of seedlings. They favor plant–microbe interactions and nutrients uptake. When invading the soil, RH cells have to penetrate a dense medium exhibiting a variety of physical properties, such as mechanical resistance, that impact the growth and survival of plants. Here we investigate the effect of the mechanical resistance of the culture medium on RH-physical and phenotypical parameters such as length, time, and speed of growth. We also analyze the impact of the environment on nuclear dynamics. We show that the RH growth rate and the nucleus speed decrease similarly as mechanical resistance increases while the time of growth of RH cells is invariable. Moreover, during RH growth, the nucleus-to-tip distance was found to decrease when the stiffness of the environment was increased. Along this line, using Latrunculin B treatment in liquid growth media, we could internally slow down RH growth to reach speeds similar to those observed in stiff solid media while the nucleus-to-tip distance was only slightly affected, supporting thus the idea of a specific effect of mechanical resistance of the environment on nucleus dynamics. [ABSTRACT FROM AUTHOR]

To receive a high-quality welding structure of high-strength S700MC steel for applications in the automotive industry, newly developed electrode wires with increased silicon and manganese content were used. The strength and structural tests of the obtained joints were performed. In the weld, we identified the beneficial oxides strengthening the joint structure and unfavorable MnS inclusions. The non-metallic inclusions were formed inside the weld. Their arrangement, morphology, and chemical composition is described. A view on the high-temperature mechanisms of the formations included during the welding process with new electrode wires is presented. It was found that the dominant mechanism of the inclusion formation and the temperature of the welding process impact the content and varied morphology of inclusions, thus determining the exploitation time of the welded joints obtained. The obtained MAG joints made S700MC steel, due to the formation mainly of oxide inclusions and a relatively small amount of MnS phase, were characterized by a high value of yield and tensile strength, which makes them a promising solution for the automotive industry, especially against the background of connections from the discussed steel grade presented in the literature. [ABSTRACT FROM AUTHOR]

The application of advanced high-strength steel grades (AHSS) in different kinds of industry is connected to more than their attractive mechanical properties. The present paper focuses on improving the welding Docol 1300M steel to reach an acceptable microstructure and mechanical parameters. It was decided to manufacture joints with different welding parameters using different filler materials. The electrode wires were varied to increase the carbon content in the weld, and nitrogen was added to the argon shielding mixture to obtain non-metallic inclusions that strengthen the fusion zone. Specimens of joints welded with the gas metal arc welding (GMAW) process for non-destructive and destructive tests were examined. Tensile and bending tests as well as microscopic inspections using a light (LM) and scanning electron microscope (SEM) were also conducted. The results from the fatigue test confirmed the validity of the proposed welding process for the Docol 1300M joint. The collected data enabled the following conclusion: The article's novelty is represented by the use of shielding gas mixtures containing argon and nitrogen in the GMAW welding process of AHSS steel to create titanium non-metallic inclusions, which will translate into better performance properties of the entire joint. [ABSTRACT FROM AUTHOR]

As a fact of matter, the aim of this paper is to produce a new ecological mortar based on recycled aggregates from hollow concrete blocks waste and reinforced with natural Diss fibers for use in manufacturing filling materials and masonry blocks, for the purpose of reducing the impact of such waste on the environment on the one hand, and making the most of the Diss plant, which is abundant in Algeria, on the other. In virtue of which, for achievement purpose of this work, we partially substituted the crushed-stones sand (CS) of a mortar reinforced with Diss fibers with recycled sand (RS) from hollow concrete blocks waste at rates of 15%, 30% and 50%. Besides, the produced mortars were subjected to density, consistency and air occlusion tests in their fresh state; moreover, they have alike been subject to compressive strength, flexural tensile strength, water absorption by immersion and capillary action, chemical resistance to acid and alkali, and chloride ion penetration tests in the hardened state. As consequence, the results illustrated improvements in consistency, mechanical strength and resistance to chemical attacks, with a slight increase in chloride ion penetration. [ABSTRACT FROM AUTHOR]

Throughout history, bricks have been an important part of monumental and vernacular architecture but often suffer alteration due to physico-chemical weathering and require replacement. Local soil could be used to fabricate compatible replacement bricks with similar physico-chemical characteristics as historic ceramics. Here the mineralogical and textural evolution of bricks prepared with local soil containing iron-oxyhydroxides and organic matter and fired between 800–1100 °C are evaluated. The study provides direct evidence for solid state formation of anorthite in contact with carbonate grains and sheds light on the fate of iron compounds under oxidizing and reducing conditions (induced by the presence of organic matter) and their influence on the textural evolution of fired bricks. Brick durability and compatibility are discussed based on their hydric and mechanical performance. The findings of this study further the understanding of temperature-induced soil mineral changes and have practical implications for the design of compatible bricks for heritage conservation and new construction. [ABSTRACT FROM AUTHOR]

Since treelines are generally fire-free, the trees growing there are expected to have thin bark, unless adaptation to other factors than fire results in the selection of a thick bark. Related to this is also higher proportional investment in inner bark in such an environment of infrequent fire. This study has considered stem bark thickness both in absolute and relative terms and also in the frame of the composition of outer and inner bark components of 20 tree species along an elevation transect (2100–3300 m) in high ranges of the Central Himalaya leading to treelines. The study species varied from 2.1 to 16.2 mm for total bark thickness and from 1.2 to 18.85% for relative bark thickness. The average absolute total bark thickness across the tree species decreased with elevation from forest to treeline, both when trees of all diameters (10.2 ± 0.84 mm for forest and 6.9 ± 1.79 mm for treeline) and those of the same stem diameter range (18–20 m) were compared (9.10 ± 1.30 mm for forest species and 6.38 ± 1.31 mm for treeline species). Nevertheless, the treeline bark thickness was similar to those of several forest communities considered to have comparatively thick bark. Like many other biological structures, bark carries out multiple functions; therefore, its thickness could be affected by more than one environmental factor. We suggest that the requirement of mechanical resistance to the snowfall, rainstorms, wind and adaptation to a high sunlight and UV radiations or storage of water, and non-structural carbohydrates could affect total, outer and inner bark thickness. Studies on these aspects in similar ecosystems may help understand the multi-functional attributes of the bark. For trees of comparable sizes (trees with 18–20 cm diameter at breast height) treeline species also had lower relative bark thickness (< 6%) than trees of forest below it (> 7%). The median proportion of inner bark of the total bark (70.5%) for our 20 species was more than that for savannas (~ 50%), exposed to frequent fire regime and similar to those of in cool sclerophyllous forests and temperate rain forests where fire return time is > 100 years. However, it was lower than the inner bark proportion reported for tropical rain forests. To conclude, in spite of a fire-free environment, the Himalayan treeline and adjoining forest species show mixed bark characters. [ABSTRACT FROM AUTHOR]

Objective: Self-sufficiency and reliance on natural materials are fundamental principles of Iranian architecture, with brick being a locally abundant material in Iran. Over time, brick buildings require retrofitting, restoration, and enhancement. To gain a deeper understanding of brick and its retrofitting, it is essential to analyze historical bricks and incorporate past experiences in brick making. This research aims to examine the technical characteristics of bricks used in the historical buildings of Kashan city across different time periods. Five brick samples from these historical structures have been selected for analysis. Method: The research employs a quantitative approach based on field studies and laboratory experiments. The experiments are categorized into three groups. The first group comprises basic tests, including density, specific gravity, moisture content, and water absorption. The second group encompasses mechanical tests, focusing on compressive and bending strength. The third category involves chemical tests conducted through X-ray Diffraction (XRD) analysis. Results: The tests revealed that the specific weight of the samples ranged from 1.6 to 2.14 grams per cubic centimeter, while water absorption varied between 9.3 and 18.5 percent. The compressive strength was found to be between 53.12 and 195.27 kg/cm², and the bending strength ranged from 11.62 to 125.83 kg/cm². The findings indicate that basic characteristics significantly influence mechanical properties. As specific weight and volume density of the samples increase, their internal pore structure diminishes, leading to reduced moisture content and lower water absorption. Furthermore, higher sample density correlates with increased compressive and bending strength. The predominant chemical composition in the samples was quartz, while the presence of gypsum contributed to decreased mechanical resistance. In contrast, higher levels of quartz, anorthite, and albite enhanced the resistance of the samples Conclusions: The physical and mechanical characteristics of brick samples remain relatively stable over time. Consequently, it appears that the resistance parameters are more influenced by the quality of the raw materials, sample density, and production methods rather than the age of the samples. [ABSTRACT FROM AUTHOR]

Bamboo is already a convenient construction resource, as it offers an efficient structural performance. As this plant has native varieties adapted to different climates and soils of Brazil, bamboo silviculture can be intensified to supply the national industry. Three bamboo species from Brazil (Dendrocalamus asper, Bambusa tuldoides, and Phyllostachys aurea) were analyzed for the flexural load capacity applied on the internal and external surfaces. Specimens were prepared without knots and with knots centered at the middle of each sample. In total, 240 samples were tested in terms of static bending and dynamic bending (impact). The results showed a higher flexural elasticity and a higher proportional limit strength of knotted P. aurea. The presence of knots provided higher values of ultimate strength in P. aurea, even reducing the bamboo flexibility. Also, P. aurea exhibited the best characteristic of flexural dynamic energy absorption among the three bamboo species under evaluation. [ABSTRACT FROM AUTHOR]

This article comments on: Yi-Yi Meng, Wei Xiang, Yin Wen, Dong-Liu Huang, Kun-Fang Cao, and Shi-Dan Zhu, Correlations between leaf economics, mechanical resistance and drought tolerance across 41 cycad species, Annals of Botany, Volume 130, Issue 3, 1 September 2022, Pages 345–354 https://doi.org/10.1093/aob/mcab146

Mimicking nature through nano structuring allows the creation of multifunctional surfaces with remarkable properties, such as anti-reflectivity, high optical transmittance and controlled wettability, enabling anti-icing or anti-fogging behaviors. These multifunctional surfaces have gained significant interest in civil and military domains. However, integrating them into real-life applications faces challenges related to cost, high-throughput large-scale compatible nanofabrication techniques, and their mechanical resistance. While sub-wavelength patterning improves the optical performance, it often comes at the cost of compromising the mechanical resistance. As optical performance improves, mechanical resistance tends to deteriorate, and vice versa. To address this challenge, taking inspiration from the lotus leaf structure, where patterns are covered by a thin 2D wax film, covering the patterns of structured surfaces with a protective layer can be a viable solution. This protective layer should enhance the mechanical resistance of the surface without compromising its multifunctional capabilities. This review highlights the most suitable materials that can be employed as protective coatings and their potential to enhance the resistance of structured surfaces. The fundamental concept behind the creation of multifunctional optical surfaces is discussed, followed by a comprehensive examination of mechanical tests that can be utilized to characterize their mechanical behavior. This review aims to pave the way for the development of durable multifunctional optical surfaces, making them more amenable to industrial applications. [ABSTRACT FROM AUTHOR]

The underutilization of natural waste from date palm plantation maintenance presents an opportunity for the production of sustainable building materials. This study investigates the mechanical properties and environmental sustainability of adobe bricks reinforced with date palm waste (DPW) and a small percentage of cement. Adobe bricks were stabilized using 7% cement by weight and varying proportions of DPW (0%, 0.5%, 1%, and 1.5% by weight), followed by curing under two distinct conditions: moist storage (MS) and open-air (AF). It was observed that bricks cured under MS conditions significantly outperformed those cured in AF, evidenced by a 47.05% reduction in capillary absorption coefficient compared to the reference brick. Despite a decrease in compressive strength due to DPW incorporation, the bricks exhibited increases in capillary and total absorption while still satisfying earth construction standards. Notably, flexural strength improved by 41.66% under MS curing. Enhanced erosion and abrasion resistance, as well as improved performance throughout wetting/drying cycles, were also recorded. These enhancements underscore the potential of DPW as a renewable additive in the formulation of adobe bricks for ecological and durable housing. The study not only proposes a novel use for date palm byproducts but also contributes to the advancement of environmentally-friendly construction methodologies. [ABSTRACT FROM AUTHOR]

For many industrial applications, the simultaneous presence in a material of different functional properties is necessary. The main interest lies in making a single material more versatile and durable, less fragile and more efficient. In this study, two concomitant properties in the same material were mainly studied: resistance to cracking and the increase in its hydrophobic properties. The chosen process was the sol-gel route due to its versatility and the ease of formulating materials from various precursors in order to obtain (multi)functional materials. In this paper, sol-gel coatings were prepared with tetraethoxysilane, methyltrimethoxysilane and diethoxydimethylsilane as precursors. Tetraethoxysilane was mainly used to improve the material's mechanical properties, especially hardness, and silicon oil was added to improve its hydrophobic behavior. The integration of silicon oil was monitored via 29Si NMR. Microstructural characterizations were carried out to correlate the multi-scale properties with the microstructure of the derived films. Young's modulus and hardness were measured to highlight the effect of key formulation parameters on the mechanical strength of the coatings. The synergistic effect of these precursors is underlined as well as the beneficial effect of silicon oil (generated in situ or precondensed). [ABSTRACT FROM AUTHOR]

BACKGROUND: We compared the raw Ti–Al–V super alloy transpedicular implant screws with boronized and surface-hardened transpedicular implant screws. OBJECTIVE: To improve patients' postoperative prognosis with the production of harder and less fragile screws. METHODS: Surface hardening was achieved by applying green-body encapsulation of the specimen with elemental boron paste which is sintered at elevated temperatures to ensure the boron-metal diffusion. Boron transported into the Ti–Al–V super alloy matrix gradually while suppressing aluminum and a homogeneously boronized surface with a thickness of ∼15 microns was obtained. The uniform external shell was enriched with TiB2, which is one of the hardest ceramics. The Ti-Al-V core material, where boron penetration diminishes, shows cohesive transition and ensures intact core-surface structure. RESULTS: Scanning electron microscope images confirmed a complete homogeneous, uniform and non-laminating surface formation. Energy-dispersive X-ray monitored the elemental structural mapping and proved the replacement of the aluminum sites on the surface with boron ending up the TiB2. The procedure was 8.6 fold improved the hardness and the mechanical resistance of the tools. CONCLUSIONS: Surface-hardened, boronized pedicular screws can positively affect the prognosis. In vivo studies are needed to prove the safety of use. [ABSTRACT FROM AUTHOR]

This study created green multifunctional geopolymeric sorbent material with strong cationic dye adsorption capacity and superior mechanical strength to broaden lead sludge (LS)-based geopolymer applications. In this study, two geopolymeric sorbents (Go and G) were fabricated using slag blended with 0 and 50 wt% LS, respectively and activated with 6 wt% NaOH. The Go and G specimens were normally cured for up to 28 days, while G specimens were hydrothermally cured at different steam-pressures to modify/improve histological characteristics as well as mechanical resistance. The selected sorbents were characterized via XRD, FTIR, TGA/DTG, XPS, N2-adsorption/desorption and SEM/EDX techniques. G/5 bar′s high strength and adsorption capacity may be due to the production of CSH, CAH, CASH, and NASH, which formed a fine mesoporous zeolitic structure with the highest BET-surface area (64.55 m2/g) and lowest BJH-maximum pore diameter (9.68 nm). The maximum MB adsorption capacity of the synthesized adsorbent was 230.4 mg/g.

Considering that global awareness for sustainable development has risen to face environmental damages, different building materials have been considered from a mechanical perspective. In this sense, considering the richness of South America regarding its woods, the Guayacan and the Ecuadorian oak timbers have not been previously characterized. The present research has performed mechanical, thermal, and moisture content characterizations to acknowledge the benefits of considering these materials for the building industries. In this sense, Guayacan has been shown to have lower thermal conductivity, making it ideal for thermal insulation; the oak from Manabi showed the best compressive strength; while the oak from El Oro stands with the best tensile strength; and the oak from Loja showed the best modulus of elasticity. On the other hand, all the materials were compared by multicriteria decision methods to select the best, by using the COPRAS method driven by the objective entropy-weighted method, showing that the oak from Loja is the best choice considering the advantage that presents with the modulus of elasticity. In this sense, it is concluded that regarding the mechanical properties, there is not much difference for the compression, bending, and tensile strength; nevertheless, for the modulus of elasticity the oak from Loja stands out, making it a factor to be considered in the selection of a wood for building applications that is corroborated through multicriteria decision methods.

This study aimed to investigate the technical feasibility of replacing cement in mortar production with sludge generated in wastewater treatment plants (WWTPs), prepared using different treatments. The sludge used in the experiments was processed using four different methods to investigate the effect of processing on the mechanical strength of the specimens. The sludge was then mixed with mortar in different proportions, and samples were produced for flexural and compressive strength tests. The results showed that specimens with 7% sludge from the burned treatment exhibited the highest resistance, surpassing the standard. Specimens with sludge from the drying treatments showed similar results. This study found that using sludge in mortar production could lead to energy savings compared to traditional cement production methods. Moreover, the incorporation of sludge resulted in mortars that met the specifications of the EN 998-1:2018 standard, thereby indicating their technical feasibility. Therefore, this study demonstrated the potential of using sludge from WWTPs as a substitute for cement in mortar production, which could contribute to the reduction in the environmental impacts caused by civil construction and the development of sustainable alternatives for the disposal of sludge generated in WWTPs.

Abstract Mimicking naturethrough nanostructuring allows the creation of multifunctional surfaces withremarkable properties, such as anti‐reflectivity, high optical transmittanceand controlled wettability, enabling anti‐icing or anti‐fogging behaviors. These multifunctionalsurfaces have gained significant interest in civil and military domains. However,integrating them into real‐life applications faces challenges related tocost, high‐throughput large‐scale compatible nanofabrication techniques, andtheir mechanical resistance. While sub‐wavelength patterning improves the optical performance,it often comes at the cost of compromising the mechanical resistance. As opticalperformance improves, mechanical resistance tends to deteriorate, and viceversa. To address this challenge, taking inspiration from the lotus leafstructure, where patterns are covered by a thin 2D wax film, covering thepatterns of structured surfaces with a protective layer can be a viablesolution. This protective layer should enhance the mechanical resistance of thesurface without compromising its multifunctional capabilities. This reviewhighlights the most suitable materials that can be employed as protectivecoatings and their potential to enhance the resistance of structured surfaces.The fundamental concept behind the creation of multifunctional optical surfacesis discussed, followed by a comprehensive examination of mechanical tests thatcan be utilized to characterize their mechanical behavior. This review aims topave the way for the development of durable multifunctional optical surfaces,making them more amenable to industrial applications.

The evolution of construction engineering depends on the development of cementitious materials with optimized properties and lower environmental impacts, such as the preparation of mortars with higher mechanical resistance and durability. Nanotechnology is a promising tool for industrial innovation, enhancing material properties like durability and mechanical performance. Thus, herein, we prepared mortars incorporating ZnO nanoparticles and evaluated their properties. The results showed that smaller percentages of ZnO presented better performance in consistency tests, and all samples containing ZnO showed higher mechanical resistance than the reference, thus suggesting the great potential of nanoparticles in optimizing the mechanical properties of mortars. [ABSTRACT FROM AUTHOR]

Due to its long and continuous cellulose fibers, flax offers excellent specific tensile strength and stiffness relative to other natural fibers such sisal or jute, and it is widely used as fiber reinforcement in composites with relevance in industries such as automotive, sports and maritime environments. However, the use of natural fibers poses additional challenges relative to synthetic fibers in ensuring the functional lifetime of composites; in particular, water resistance and resistance against UV conditions should be improved for outdoor use. Therefore, a protective coating that offers high resistance against environmental conditions and mechanical damage can be applied to avoid direct surface exposure of natural fibers. The linseed oil or wax coatings increase the hydrophobic surface properties and limit water ingress, but they have drawbacks such as extended curing periods via oxidative crosslinking and weak mechanical performance. In seeking alternatives for natural fiber composites, the potential of bio-based crosslinked coatings to enhance mechanical robustness, surface protection and durability was explored by screening various coating grades, including bio-based epoxy resin, diluents and crosslinkers. The epoxy coatings with a bio-based phenalkamine crosslinker offer higher hardness and scratch resistance, and the water resistance was improved in the presence of an amine crosslinker with long alkyl chains. In parallel, the mechanical abrasion resistance of the crosslinked coatings significantly increased in relation to the intrinsic mechanical properties and crosslinking density of the coatings. The processing of the epoxy coatings was further enhanced by adding a bio-based trifunctional diluent with low viscosity while providing limited shrinkage and good compatibility with the composite substrate. Moreover, the UV resistance was better for epoxy coatings with a bio-based diluent, likely via migration effects and the formation of a protective layer at the outer surface. [ABSTRACT FROM AUTHOR]

Liquid‐infused surfaces exhibit remarkable repellency properties toward water, oils, and complex fluids and are widely applied to maintain clean, operational, and high‐performing surfaces in various fields, from the biomedical sector to marine infrastructure. Polydopamine (PDA) forms an ideal base layer for the development of such coatings as it adheres to virtually any substrate and can be chemically modified via amino‐containing molecules to adjust the surface properties. Here, strategies are explored to increase the mechanical stability of such coatings by i) incorporating imidazole during film formation to increase crosslinking, and ii) formation of a composite consisting of the organic PDA and an inorganic siliceous porous coating by infiltration of a preformed porous silica layer with PDA. Both strategies exhibit improved resistance to tangential shear assessed by a sandpaper abrasion test and to dynamic impact assessed by a sand trickle test. These improved mechanical properties are successfully transferred to liquid‐infused surfaces created from such modified PDA base layers. The most durable coatings retain efficient liquid repellency after 25 abrasion cycles, indicating improved resilience in real‐world applications. [ABSTRACT FROM AUTHOR]

The goal of this research was to investigate the effect of different types of nanoparticles on the UV weathering resistance of polyurethane (PU) treatment in polyester-based fabrics. In this regard, zinc oxide nanoparticles (ZnO), hydrophilic silica nanoparticles (SiO2 (200)), hydrophobic silica nanoparticles (SiO2 (R812)), and carbon nanotubes (CNT) were mixed into a waterborne polyurethane dispersion and impregnated into textile samples. The puncturing resistance of the developed specimens was examined before and after UV-accelerated aging. The changes in chemical structure and surface appearance in nanoparticle-containing systems and after UV treatments were documented using microscopic pictures and infrared spectroscopy (in attenuated total reflectance mode). Polyurethane impregnation significantly enhanced the puncturing strength of the neat fabric and reduced the textile's ability to be deformed. However, after UV aging, mechanical performance was reduced both in the neat and PU-impregnated specimens. After UV treatment, the average puncture strength of all nanoparticle-containing systems was always greater than that of aged fabrics impregnated with PU alone. In all cases, infrared spectroscopy revealed some slight differences in the absorbance intensity of characteristic peaks for polyurethane polymer in specimens before and after UV rays, which could be related to probable degradation effects. [ABSTRACT FROM AUTHOR]

Abstract The growth of cities affects their permeable surface, which can unbalance hydrological cycles. The pervious concrete can be a viable solution to combat urban environmental impacts in this subject. This type of concrete can be told apart by the presence of interconnected pores and its drainage capacity. This paper aims to analyze the relationship between aggregate shape, mechanical resistance, and permeability of pervious concrete slabs containing steel slag. A Digital Image Processing (DIP) based method was used to measure aggregate shape properties. Three different mixes, using three types of coarse aggregate (gravel 12.5 mm, gravel 9.5 mm, and coarse steel slag), and a type of fine aggregate (fine slag) were tested, and flexural strength, flow, and permeability coefficients were obtained for the slabs. Results showed the potential of using steel slag, with higher flexural strength results (4.61 MPa). Indications of the relationship between aggregate shape parameters and slab properties were determined, with more polished, more angular, and more spherical material resulting in higher flexural strength values and lower permeability coefficient. The inverse relationship between the slabs’ permeability parameters and flexural strength was observed.

Abstract Liquid‐infused surfaces exhibit remarkable repellency properties toward water, oils, and complex fluids and are widely applied to maintain clean, operational, and high‐performing surfaces in various fields, from the biomedical sector to marine infrastructure. Polydopamine (PDA) forms an ideal base layer for the development of such coatings as it adheres to virtually any substrate and can be chemically modified via amino‐containing molecules to adjust the surface properties. Here, strategies are explored to increase the mechanical stability of such coatings by i) incorporating imidazole during film formation to increase crosslinking, and ii) formation of a composite consisting of the organic PDA and an inorganic siliceous porous coating by infiltration of a preformed porous silica layer with PDA. Both strategies exhibit improved resistance to tangential shear assessed by a sandpaper abrasion test and to dynamic impact assessed by a sand trickle test. These improved mechanical properties are successfully transferred to liquid‐infused surfaces created from such modified PDA base layers. The most durable coatings retain efficient liquid repellency after 25 abrasion cycles, indicating improved resilience in real‐world applications.

This study aimed to investigate the technical feasibility of replacing cement in mortar production with sludge generated in wastewater treatment plants (WWTPs), prepared using different treatments. The sludge used in the experiments was processed using four different methods to investigate the effect of processing on the mechanical strength of the specimens. The sludge was then mixed with mortar in different proportions, and samples were produced for flexural and compressive strength tests. The results showed that specimens with 7% sludge from the burned treatment exhibited the highest resistance, surpassing the standard. Specimens with sludge from the drying treatments showed similar results. This study found that using sludge in mortar production could lead to energy savings compared to traditional cement production methods. Moreover, the incorporation of sludge resulted in mortars that met the specifications of the EN 998-1:2018 standard, thereby indicating their technical feasibility. Therefore, this study demonstrated the potential of using sludge from WWTPs as a substitute for cement in mortar production, which could contribute to the reduction in the environmental impacts caused by civil construction and the development of sustainable alternatives for the disposal of sludge generated in WWTPs. [ABSTRACT FROM AUTHOR]

Copyright of Matériaux et Techniques is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Abstract Cryogenic treatments represent an innovative technology developed with the aim of improving the performance of metallic alloys. The beneficial effects on steels are well documented in the literature, whereas their influence on other materials, such as aluminum alloys, is still not completely clarified. Even if the scientific literature reports conflicting data and conclusions, the industrial applications of such treatments are constantly growing. In the present experimental work, the mechanical and corrosion properties of a high-performance 7050 aluminum alloy plate were studied after cryogenic treatment at − 196 °C in liquid nitrogen. Tensile tests were performed on heat-treated samples, and intergranular corrosion tests were carried out on prismatic samples, according to ASTM G110-92 standard. The specimens were exposed to the corrosive environment and the effect of intergranular corrosion was measured by quantitative analysis using light-optical microscopy (LOM). Whereas trifling variation was observed in the mechanical resistance and plastic behavior, the corrosion tests showed a benefic effect of the cryogenic treatment. The microstructure was investigated by FEG-SEM analysis, revealing a different distribution of precipitates near the grain boundaries, which was able to reduce the electrochemical potential difference among these regions and the center-grain.

In this research, flax seed mucilage was extracted. Composite film of sodium alginate and flax seed mucilage was prepared. Norbixin pigment and tungsten oxide (WO3) nanoparticles were used to modify the film structure. The color, crystallite, thermal and mechanical properties of the films were investigated. Also, the antibacterial properties of the prepared films against Escherichia coli and Staphylococcus aureus bacteria were investigated. The obtained results showed that the pure alginate/mucilage film does not have very high transparency, which is reduced by adding tungsten oxide nanoparticles and norbixin pigment. The effect of tungsten oxide nanoparticles in reducing film transparency has been greater than that of norbixin. Examining the factor a shows that this factor has increased with the increase of norbixin and tungsten oxide nanoparticles. Examining factor b (blue - yellow) shows that with the increase of norbixin and tungsten oxide nanoparticles, this factor has increased. By examining the XRD spectrum of the pure alginate/mucilage film, it was found that this film showed two broad peaks at 2θ of 10° and 20°, which indicates the relatively amorphous structure of this film. In the alginate/mucilage film modified with tungsten oxide nanoparticles, the peaks related to the crystalline nanoparticles in 2θ of approximately 25, 30, 35, 40, 50, 55 and 65 degrees are quite clear, which shows that these nanoparticles improve the crystalline structure of the film. By examining the TGA curves of the films, it was found that the addition of tungsten oxide nanoparticles and norbixin pigment increased the thermal stability of the film. Examining the antibacterial property of the films showed that the addition of tungsten oxide nanoparticles and norbixin pigment increased the antibacterial property of the film significantly (p<0.05). [ABSTRACT FROM AUTHOR]

(1) Background: Aesthetic dentistry has become one of the most dynamic fields in modern dental medicine. Ceramic veneers represent the most appropriate prosthetic restorations for smile enhancement, due to their minimal invasiveness and highly natural appearance. For long-term clinical success, accurate design of both tooth preparation and ceramic veneers is of paramount importance. The aims of this in vitro study were to assess the stress in anterior teeth restored with Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) ceramic veneers and compare the resistance to detachment and the fracture of ceramic veneers prepared using two different designs. (2) Methods: Sixteen lithium disilicate ceramic veneers were designed and milled using the CAD-CAM technology and divided into two groups according to the preparations (n = 8): Group 1, conventional (CO), with linear marginal contour and Group 2, crenelated (CR), the latter with our novel (patented) sinusoidal marginal design. All samples were bonded to anterior natural teeth. The mechanical resistance to detachment and fracture was investigated by applying bending forces on the incisal margin of the veneers in order to determine which type of preparation leads to better adhesion. An analytic method was employed, as well, and the results of the two approaches were compared. (3) Results: The mean values of the maximum force recorded at the veneer detachment were 78.82 ± 16.55 N for the CO group and 90.20 ± 29.81 N for the CR group. The relative increase, equal to 14.43%, demonstrated that the novel CR tooth preparation provided higher adhesive joints. In order to determine the stress distribution within the adhesive layer, a finite element analysis (FEA) was performed. The statistical t-test showed that the mean value of the maximum normal stresses is higher for the CR-type preparations. (4) Conclusions: The patented CR veneers represent a practical solution to augment the adhesion and mechanical properties of ceramic veneers. The obtained results demonstrated that CR adhesive joints triggered higher mechanical and adhesive forces, which subsequently led to a higher resistance to detachment and fracture. [ABSTRACT FROM AUTHOR]

Background: Appropriate abutment selection according to the individual specificities of each patient is a leading factor in achieving high aesthetic results. Standardized titanium abutments are the most widely used due to their easy use and low cost. It is considered that customized abutments can eliminate many of the complications seen with factory abutments in prosthetic treatment. The purpose of this study is to evaluate whether customized abutments have better mechanical behavior in laboratory settings than standard ones. The null hypothesis is that customized abutments have better resistance to cyclic load and compression than factory abutments. Methods: The study model includes thirty implant suprastructure samples, fabricated digitally, divided into three groups according to the type of implant abutment and the used material: Group A (control group) comprised monolithic implant crowns made of zirconium dioxide and a titanium base; Group B (test group) comprised monolithic implant crowns made of zirconia implant crowns and a customized titanium alloy abutment; and Group C (test group) comprised monolithic implant crowns made of lithium disilicate and a customized titanium alloy abutment. The samples were subjected to dynamic load in a computer-controlled 2-axis machine that simulated masticatory movements, Chewing Simulator CS-4 (SD-Mechatronik, Westerham, Germany), for 250,000 cycles at a frequency of 2 Hz. The samples were then subjected to compressive strength testing in an Instron M 1185 universal testing machine. A metal steel disc was used as an antagonist, exerting pressure at a rate of 2 mm/min at room temperature on each sample. After conducting the laboratory tests, the samples were examined by an experienced expert under a Carl Zeiss microscope (Carl Zeiss Microscopy GmbH, Jena, Germany). Results: All samples were found to have passed the fatigue test in the masticatory simulator without any of the listed complications. The average value of the compressive strength at which the structures in each group fracture is as follows: Group A, 5669.2; Group B, 3126.5; and Group C, 1850.6. Based on the average values, it can be concluded that the combination of materials used in Group A has the greatest resistance. Conclusion: The weak link in the prosthetic complex consisting of a crown and abutment seems to be the crown. No abutment failure was found regardless of the type. However, monolithic zirconia crowns over standard titanium abutments withstand higher mechanical forces compared with zirconia and lithium disilicate crowns over customized ones. Detailed studies in clinical settings may provide more in-depth information on this issue. [ABSTRACT FROM AUTHOR]

At ambient temperature, concrete exhibits excellent mechanical properties. However, understanding the behavior of concrete under high-temperature conditions is crucial, especially for civil engineering applications during fire incidents. The growing use of plastic-based products has led to a significant increase in polymer waste, posing environmental challenges. The valorization of this plastic waste in the form of fibers presents both economic and environmental advantages. This study focuses on the study of the behavior of sand concrete incorporating polyethylene terephthalate (PET) fibers with percentages of 1% and 2% at high temperatures (100, 300, 500 and 700 °C). Specimens are tested for residual mass loss, residual compressive and tensile strength. A complementary analysis of SEM makes it possible to confirm and better clarify the morphology of the concretes of sand before and after the rise in temperature. The results obtained from this study indicate that the residual resistance is reduced with the rise in temperature for all the concretes studied, except in the temperature range of 300 °C, in which a slight improvement in resistance is noticed. The incorporation of PET fibers in the test concretes does not enhance their residual behavior significantly. However, it does serve as an effective solution by reducing the susceptibility to spalling, by preventing cracking and by fulfilling a similar role to that of polypropylene fibers. [ABSTRACT FROM AUTHOR]

Flexible pipelines connect offshore platforms to subsea production systems due to their high flexibility, applicability, and recycling. Flexible armor layers in flexible pipelines are constructed using the parallel helical wrapping of several rectangular wires. The complex stress modes to which pipelines are subjected provide complex failure modes that are mostly unpredictable, requiring expensive pipeline integrity verification methods. This work investigates texture and microstructure evolution in pearlite-drawn wires due to different heat treatments. The material was subjected to annealing and isothermal heat treatments to obtain changes in its microstructure and texture. The changes were characterized using SEM, XRD, and EBSD techniques. Samples were subjected to tensile testing to evaluate their mechanical properties. This work revealed that annealing and isothermal treatments mainly modify the material microstructure, whereas annealing provides a material with grains with ease of deformation. In contrast, isothermal treatment provides grain growth with high internal energy and more deformation resistance. Annealing increases the intensity of all texture components, while isothermal treatment reduces intensity. These findings provide insights into the relationship between material properties and heat treatments, which can be used to optimize the design and performance of flexible pipelines, thereby reducing the need for expensive integrity verification methods. [ABSTRACT FROM AUTHOR]

This research presents a practical approach to the development of the intergranular corrosion in 7050 - T7451 aluminum alloy used in the construction of manifold components of an aircraft structure. At first, it is presented what type of corrosion this is and how it develops in the crystalline structure, noting which variables contribute to the aggravation of this problem and their impacts on aviation, since this is the beginning of a number of structural defects included fatigue, which stands out even more because of the circumstances that are presented. The performance of the tests in laboratory seeks to evaluate the reactions of the material when exposed to cutting fluid and thermal variations for a long period; the development of corrosion in the microstructure has been simulated, and with this the loss of mechanical resistance of the samples could be evaluated. The results obtained indicate that the cutting fluid even slowly, showed effects in the propagation of corrosion in the alloy of aluminum studied and reduced your mechanical strength.

Advanced high-strength steel (AHSS) is being used increasingly often in the structure of means of transport. Welds made of these steels can crack in the heat-affected zone (HAZ) and have inferior mechanical properties compared to the base material. The goal of this paper was to solve the technological and material problem of obtaining high- strength thin-walled welded structures of AHSS steel designed for heavily loaded elements of transport means. The novelty of the article is its presentation of a modified welding process which enables a high-strength structure of the obtained joint to be obtained without welding defects and incompatibilities. Copper backing was selected as an effective method of heat dissipation in the process, and, using the basic solutions method, the leverage of a heat flow process in the weld method deposit (WMD) was checked after cooling down the substrate. The fundamental solutions method was used to determine the optimal shape of the backing. It has been shown that the new backing affects the structure and mechanical properties of welds. In order to verify the newly developed method, tensile tests of the obtained joint were carried out, the hardness was assessed, the metallographic structure was analyzed, and non-destructive tests were performed. The developed material and technological solution were used, for example, for the construction of the arm element of the mobile platform.

La dirección de proyectos de construcción, respetando el entorno y los parámetros ambientales es un tema ya abordado con anterioridad en multitud de trabajos científicos. Éste trabajo tiene como objetivo comparar y analizar los distintos parámetros ambientales derivados del análisis del ciclo de vida, concretamente en la etapa de producto, fases A1, A2 y A3 y los costes económicos incurridos en una estructura modelo, utilizando diferentes hormigones armados HA25, HA30, HA35, HA40, HA45 y HA50. Demostrando la utilidad que tiene para los directores de proyectos en el proceso de toma de decisiones, disponer de un análisis comparativo de parámetros medioambientales frente al coste económico. Éste estudio se ha realizado sobre una estructura en concreto, por lo que los resultados obtenidos son propios del edificio analizado. Sería muy interesante realizar éste estudio sobre una muestra de estructuras más amplia. Se podría, de ese modo, analizar cómo influyen en los parámetros ambientales otros factores como la geometría, la utilización de diferentes soluciones estructurales o diferentes datos de cálculo, como las cargas de viento o nieve. Abstract The management of construction projects, respecting the environment and environmental parameters, is a subject that has already been addressed in many scientific works. The aim of this work is to compare and analyse the different environmental parameters derived from the life cycle analysis, specifically in the product stage, phases A1, A2 and A3 and the economic costs incurred in a model structure, using different reinforced concretes HA25, HA30, HA35, HA40, HA45 and HA50, demonstrating how useful it is for project managers in the decision-making process to have a comparative analysis of environmental parameters versus economic cost. This study has been carried out on a specific structure, so the results obtained are specific to the building analysed. It would be very interesting to carry out this study on a larger sample of structures. In this way, it would be possible to analyse how other factors such as geometry, the use of different structural solutions or different calculation data, such as wind or snow loads, influence the environmental parameters.

In this work, a robust epoxy adhesive (EP) @ superhydrophobic SiO2 (SH-SiO2)-based superhydrophobic coating was prepared on the aluminum substrate by a simple one-step spraying strategy. The prepared EP@SH-SiO2 coating exhibits hierarchical micro/nanostructures and is capable of maintaining a contact angle of more than 150° after 1000 cm of abrasion length and 80 tape-peeling repetitions. Molecular dynamics (MD) simulations and quantum mechanics calculations show that the improved mechanical resistance is attributed to the enhanced interfacial interaction between the EP@SH-SiO2 coating and the underlying substrate induced by the epoxy adhesive. Electrochemical measurements in 3.5 wt% NaCl solution show the corrosion inhibition efficiency of the EP@SH-SiO2 coating reaches up to 99.99%, and even after 8 days of immersion, the low frequency impedance modulus of the EP@SH-SiO2 sample is still ∼1 order of magnitude higher than that bare aluminum, demonstrating excellent long-term corrosion protection. The diffusion behavior of the corrosive medium in the EP@SH-SiO2 coating was revealed by MD simulation to support the experimental results. Additionally, the EP@SH-SiO2 coating exhibits good chemical stability and hydrophobic repair properties. This work will provide a new perspective for the preparation and study of robust superhydrophobic aluminum for corrosion protection properties.

Traditional architecture characteristically uses locally available materials to develop constructive systems and techniques, providing an optimum response to the needs of the population. This study focuses on half-timber walls as a traditional technique taking material form in a wide range of variants found mostly in the northwest half of Spain. Primarily aiming to ensure the broad objective of in-depth documentation, understanding, and study, the microscopic analysis of 24 timber samples obtained from different half-timber walls is proposed. This analysis aims to identify the species or species groups used and to establish a correlation with different aspects of construction including structural resistance, durability, and workability. This makes it possible to identify the predominant use of species found close to the locations from which the samples are obtained, using relatively resistant species for the structural elements of the half-timber wall, as well as the use of species with flexible and easily malleable branches for the construction of the enclosure panels. This indicates that, among the species available in a given location, builders have a degree of knowledge on the characteristics of the material, so they could choose the most suitable ones or develop specific constructive solutions based on these characteristics. [ABSTRACT FROM AUTHOR]

Despite the wealth of physical and chemical information available about wood torrefaction and pyrolysis, very few studies to date have focused on the transition between these two processes. It has been experimentally determined, however, that torrefaction and pyrolysis lead to very different products, indicating a change in their degradation chemistry. There exists, therefore, a need to investigate this transition between torrefaction and pyrolysis from a chemical perspective, very useful for the development of kinetic models. This study focuses on investigating thermogravimetric analysis, shrinkage, flexural strength, total weight loss, of two common industrial European wood species treated at temperatures ranging from 250°C to 400°C. A comparison reveals an obvious change in the degradation of cellulose as a function of treatment temperature that can be correlated with the yield of the main thermal treatment products, such as acetic acid, furfural, CO, H2, etc. At temperatures higher than 350°C, all wood components are extensively degraded. In conclusion, this study indicates a deep modification during the transition between torrefaction and pyrolysis. The results obtained in this study help establish specific temperature ranges, based on wood component degradation, that can be used in the refinement of kinetic models for wood thermal treatment. It is envisioned that, due to the sudden change in behavior at temperatures covering a range between torrefaction and soft pyrolysis, an adequate model with distinct stages is required. Ultimately, this study aims at defining, based on TGA, DTG, mechanical testing, color/appearance, and dimensional change results, the appropriate temperature ranges to be used in the refinement of unique kinetic models that contemplate the degradation of wood components. [ABSTRACT FROM AUTHOR]

In this work, marl clay was used because these materials have a very important industrial potentiality in several fields, namely ceramics. The objective was manufacturing expanded clay aggregate (ECA), with two main ingredients of marl and pozzolan at different percentages in order to integrate them into the concrete as aggregate. The physicochemical parameters of the mixture marl / Pozzolan was discussed and the results of the analyses, allowed deducing that the sample with 15% pozzolan has the most expansion rate of 16.8%, and its density of 1232 kg/m³ is in accordance with the international standard of expanded aggregates. The density of the concrete decreases with the quantity of ECA added and reaches its minimum with 1671 kg/m³ according to concrete with 50% of the expanded aggregate. The bending tests show the increase of the mechanical strength as a function of the quantities of aggregate added. The results show a very important potential with the addition of clay aggregates, density and water absorption decrease with the increase of the mechanical resistance. [ABSTRACT FROM AUTHOR]