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While ultra-high performance concrete (UHPC) offers numerous advantages, it also presents specific challenges, primarily due to its high cost and excessive cement content, which can pose sustainability concerns. To address this challenge, this study aims to develop cost-effective and sustainable UHPC mixtures by incorporating ground granulated blast furnace slag (GGBFS) and limestone powder (LP) as partial replacements for portland cement. Eight fiber-reinforced UHPC mixtures were investigated, with a water-to-cementitious materials (w/cm) ratio of 0.15. In four of the UHPC mixtures, 25% of the cement was replaced with GGBFS, and further, LP was added as a mineral filler, partially substituting up to 20% of the cement. In the remaining four mixtures, cement was replaced with only LP up to 20% (without GGBFS). The 28-day compressive strength of the UHPC mixture with 25% GGBFS and 20% LP was 149 MPa, 3.50% lower than the mixture without GGBFS. Its 28-day flexural strength decreased by 30%. Increasing LP replacement reduced drying and autogenous shrinkage, with a 29% shrinkage reduction at 20% LP replacement. Moreover, UHPC mixtures with GGBFS exhibited lower shrinkage compared to those without GGBFS for all LP replacements up to 20%. For evaluating the sustainability of UHPC mixtures, the cement composition index (CCI) and clinker to cement ratio (CCR) were determined. For 20% LP replacement with 25% GGBFS, CCI was 3.6 and the CCR was 0.5, 38% decrease from the global clinker to cement ratio. Overall, 20% LP replacement UHPC mixtures with and without GGBFS can produce UHPC class performance and reduce the environmental impact. [ABSTRACT FROM AUTHOR]

Thermal energy storage (TES) systems have been proven in their capacity as a crucial component of energy grids relying on renewable sources. An established sensible heat storage technology is a packed-bed TES, employing a granular filling material as a heat storage medium, which is subjected to repeated heating-cooling cycles. As a result of the recurring particle expansion and contraction, excessive stresses and strains can develop and cause material damage. This leads to the increasing need for reliable numerical tools in order to improve the TES design and increase their durability. For this purpose, we propose a continuous thermo-mechanical approach, within the framework of the theory of hypoplasticity, that can accurately predict the single as well as cyclic loading behavior of the filling material. This work focuses on the stress–strain relations and compaction mechanisms of the granular bed in contact with a storage wall with variable inclination and friction coefficient. Furthermore, the important aspect of the wall expansion under the temperature change is also taken into account as well as the specific case when the wall expands more than the granular material. By conducting comprehensive simulations, we demonstrate that our novel numerical model adheres to existing experimental investigations and mitigates shortcomings in the predictive capabilities of previous continuous approaches. [ABSTRACT FROM AUTHOR]

Small ruminants play a significant role in Mauritanian culture and traditions. The purpose of this study was to characterize the breeding system of two locally dominant breeds, the Sahelian goat and the Ladem sheep. This characterization was based on the technical and socio-economic characteristics of the breeders, as well as the morpho-biometric features of the animals. The study was conducted between April and June 2019 and involved 45 breeders located around two small ruminant pilot farms in the Benichab and Kankoussa departments of Mauritania. A questionnaire was administered to the breeders and sixteen measurements were taken on 303 animals (185 goats and 118 sheep). Small ruminant breeding in the study sites is practiced by both men (55%) and women (45%). Breeding can be focused solely on goats (38%), solely on sheep (9%), or include both species (53%). The average herd size is 20 ± 15 for goats and 19 ± 16 for sheep. For the Sahel goat, the height at the wither ranges from 68 to 78 cm in males and from 63 to 76 cm in females, while the body weight ranges from 20 to 43 kg. The most common morphotypes are multicolored (71%), with unicolored animals being less common (29%). As for the Ladem sheep (also known as Touabire), the height at the wither ranges from 70 to 87 cm in males and from 64 to 85 cm in females. The body weight ranges from 25 to 62 kg. The coat is predominantly white with black spots (91%), sometimes red or grey-spotted. The survey also identified the breeding objectives of the farmers. The breeders primarily reported objectives of conformation and growth performances (68%), followed by dual-purpose milk/meat production traits (32%) for the Ladem sheep. In the case of the Sahelian goat, milk production (73%) is the predominant objective, followed by dual-purpose milk/meat production traits (27%). Based on the collected information, tailored selection schemes have been proposed for the Ladem sheep and the Sahelian goat to improve their performances, enhance their breeding, and maintain a focus on the sustainability and resilience of these two local breeds in Mauritania. [ABSTRACT FROM AUTHOR]

The effect of direct fire on flexural behavior of small-scale fiber reinforced concrete beams under sustained loading has been studies through an experimental investigation. A mix of synthetic polypropylene structural macro and micro fibers has been used to obtain the effect of mixed fiber dosage on bearing capacity of simply supported beam under direct flame at its bottom face. The load-deflection, temperature gradient, spalling and durability time until collapse has been recorded and compared in different conditions. In order to know the effect of load level, the tests have been performed for 40% and 70% of the ultimate member capacity at normal temperature. Based on obtained test results, the use of macro synthetic fibers can increase the flexural ductility more than 50% and the durability time until failure up to 27%. The post fire behavior curves of all samples at the cooling phase have also been checked until the beam failure has been occurred including the weight losses due to spalling for both heating and cooling phases. A comparison with the results of conventional post fire loading tests on cooled samples showed that the results can be underestimated about 1.5 times compared to the direct fire test. It has also been shown that the level of sustained load directly affects the capacity, durability and ductility while the increase in the number of fibers do not necessarily improve the behavior in the same manner. [ABSTRACT FROM AUTHOR]

Bottom ash needs a pre-treatment process to produce the finer particles until it is like cement material and has a good reactivity as pozzolanic material. This research investigates the effect of using bottom ash on the durability performance of concrete. The modified process was applied to bottom ash to produce finer particles that can improve the durability performances of concrete. The concrete used in this study is self-compacting concrete (SCC) due to its convenience. The bottom ash was pretreated by mechanical grinding before being used as supplementary cement materials (SCM), later called ground bottom ash, and applied from 10% to 50% as the partial replacement by the weight of cement. BA30 showed the highest compressive strength with an increasing percentage of 32% and had a similar value to BA0. The porosity of all mixtures was under 15%. The water absorption of all mixtures was under 10%. BA10, BA20, and BA30 reduced the permeability of the SCC, while BA50 increased the permeability of the SCC. BA30 had the lowest value of RCPT as 916.22 C. The results show that bottom ash positively affects the durability performance of SCC and can be used as an SCM to produce more sustainable cement-based construction materials. [ABSTRACT FROM AUTHOR]

Using data on in situ performance of low noise pavements, three well performing mixtures were selected: SDA 4, SDA 6, and SDA 8. These mixtures and the corresponding mastic (filler + bitumen + additive) were tested for their mechanical and acoustic performance in non-aged and aged states using a multi-scale approach (mm to km). Thereafter, an optimization protocol was applied to these mastics (mm-scale) and promising combinations were implemented at the mixture scale (cm-scale). As a result, the best performing mixture parameters were implemented in the m-scale slabs where the mechanical and acoustic performance were determined. The proposed work could uniquely combine knowledge from in situ long term and laboratory performance of low noise pavements. Using a traffic simulator and measurements before and after trafficking, the acoustic modeling showed that the modified mixtures' noise levels were maintained after loading. This indicates that the modification assured acoustical integrity of the mixture after loading. [ABSTRACT FROM AUTHOR]

In this research, four industrial wastes were used for up to 80% as supplementary cementitious materials (SCMs) in cement mortar systems: ground granulated blast furnace slag, electric arc furnace slag, basic oxygen furnace slag, and waste limestone powder. Quaternary cementitious blends were prepared and studied for up to 120 days. Workability, compressive strength, durability, microstructures, and sustainability studies were performed and compared with Portland cement references. Results showed that more than 30 MPa in compressive strength can be achieved by > 50% replacement with SCMs; only 9% below the reference. Neither H2SO4 nor MgSO4 attacks resulted in critical damages; nevertheless, curing under NaCl solution showed detrimental behavior. C-S–H with a low Ca/Si ratio was identified in the mortars as the main hydration product, possibly intermixed with stratlingite, C-A-S–H and/or hydrotalcite. Environmental impact for the blended cements was determined as the CO2eq. factor from a simple life cycle assessment. The embodied greenhouse gasses varied in 260.2–541.4 kg CO2eq./ton of binder depending on the formulation. This was 40–70% less than Portland cement (922.6 kg CO2eq./ton). The production of the raw materials dominated the polluting emissions, while freight, grinding, and sieving had little environmental impact. [ABSTRACT FROM AUTHOR]

A method for creating broadband ultrathin azo dye micropolarizers is introduced, utilizing photoalignment technology and liquid crystal polymers to organize azo dyes into a long-range ordered structure. Achievements include a 3.63 μm thick polarizer with an extinction ratio over 140 and polarization efficiency over 99.3% across 400–650 nm, 5 μm × 5 μm pixel pitch flexible ultrathin checkerboard arrays and 6 μm pixel pitch flexible ultrathin one-dimensional grating with a 0.45 duty ratio through mask exposure technology. After a substrate-transfer technique, the bending cycle test demonstrates the mechanical stability and durability of the broadband ultrathin flexible polarizers, highlighting their potential for widespread use in integrated flexible optoelectronic systems. [ABSTRACT FROM AUTHOR]

This paper aimed to investigate the durability of ambient-cured fly ash-phosphogypsum blended geopolymer mortar (GPM) when exposed to a water and sulfate environment at different durations. Water absorption, porosity, and sulfate resistance tests were conducted to determine the durability. The GPM was prepared at 0 wt%, 30 wt%, and 40 wt% PG replacement of fly ash content in the mixture. The mix proportions were determined experimentally at 10 M sodium hydroxide, alkaline liquid/precursor of 0.4, sodium silicate/sodium hydroxide of 1.5, and binder/aggregate of 1.0. The samples were immersed in potable water and magnesium sulfate solution. The changes in weight, length, and compressive strength were monitored. Scanning electron microscopy-energy dispersive X-ray spectroscopy was used to analyze the structure and composition. The findings showed that GPM with 30 wt% phosphogypsum added had lower water absorption, porosity, and sulfate attack than GPM with 0 wt% phosphogypsum attributed to the formation of hydrated gels leading to a dense microstructure and improved strength. The changes in weight, length, and strength variations trend for GPM were within optimal performance standards. This has implications for the practical application of GPM in construction where it can be used as an alternative to Portland cement mortar in sulfate-rich environments. [ABSTRACT FROM AUTHOR]

The European Green Deal (EGD) has had a significant impact on EU member states. In this article, we examine the extent to which it can also have large consequences for non-members. Based on a qualitative approach comparing Norway and the UK, and drawing on a burgeoning literature on 'turbulence', we ask whether the EGD creates turbulence in non-member states, what the nature of this turbulence is, and whether the extent and nature of turbulence varies with how closely affiliated a non-member is with the EU. Despite the ambitious climate policies of both countries, we identify a significant amount of turbulence generated by the EGD. Interestingly, we also find that turbulence increases with a closer EU-affiliation. However, our analysis also reveals an impressive capacity in both countries to adapt to their turbulent conditions, and a surprising durability of climate and energy policy in the face of turbulence. [ABSTRACT FROM AUTHOR]

The influence of a Griffith fracture on magnetic fields and stress in an infinite piezomagnetic material under tension loading and magnetic has been explored using linear theory of piezomagnetic material and suitable boundary conditions. The solutions have been obtained in closed form for Mode I fracture and external loading utilised to open the fracture. The rate of energy release has been determined for the non-zero magnetic field within the fracture at the crack tip. During computation of driving force, the magnetostatic energy has been taken into account and it has been observed that the rate of energy release is the cubic function of external loading. The findings could be utilised to explain various nonlinear phenomena in piezomagnetic ceramic for structural durability. [ABSTRACT FROM AUTHOR]

The slake durability and the related deterioration mechanism of carbonaceous rocks exposed to adverse external environment are of a great importance to the stability of infrastructure. A series of laboratory tests were conducted to determine their slake durability index Idi, fractal dimension D, total organic carbon (TOC) content, and mineralogical characteristic. The results demonstrated that Idi value decreased rapidly within the first 4 cycles, and then reached a relatively stable state as the test cycle further increased, indicating that effective protective measures should be conducted at the earlier stage of wetting-drying process to minimize the durability deterioration of carbonaceous rock. The discrepancy of carbonaceous rocks in terms of mineralogical characteristic accounted for different slake durability responses at a given cycle. Carbonaceous rock with lower clay minerals content wc possessed superior slake durability performance, and a power correlation between Id6 and wc was obtained. Fractal dimension D was found to be an indicator to indirectly describe the durability characteristic of carbonaceous rock. The organic matter imposed negative impact on the slake durability, which was manifested by the carbonaceous rock with higher TOC content exhibited inferior disintegration resistance. The microstructure changes, including an increase in pore volume, pore size, layer spacing, and the presence of new crystalline-like substances, demonstrated the minerals/salts dissolution and chemical reactions within the rock matrix occurred during the slake durability test. These changes were mainly attributed to the hybrid influence of mineralogy and microstructure of carbonaceous rock. [ABSTRACT FROM AUTHOR]

This work presents simple post-treatment methods to selectively and partially remove the Pd core of Pd–Pt core–shell (Pt@Pd/C) catalysts. The proton exchange membrane fuel cell with the post-treated Pt@Pd/C cathode (Pt loading: 0.10 mg·cm−2) delivers an impressive peak power density of 1.2 W·cm−2. The partial removal of Pd core endows an ultrahigh oxygen reduction reaction (ORR) mass activity of 0.32 A·mgPGM−1 when normalized to the platinum group metal (PGM) mass, or equivalently 0.55 A·mgPt−1 at 0.9 V measured in a fuel cell. The post-treatment thickens the Pt shells and mitigates the Pd dissolution during potential cycling. As a result, the post-treated core–shell catalyst demonstrates superior durability in ORR mass activity and polarization power density retention than untreated core–shell catalyst and benchmark Pt/C. In-situ inductively coupled plasma-mass spectrometry (ICP-MS) results highlight that the amount of dissolved Pd in post-treated core–shell catalyst is 17-times lower than that of the untreated one. Our findings highlight the importance of structural tuning of catalysts in enhancing their mass activity and durability. [ABSTRACT FROM AUTHOR]

Developing natural cotton textiles in personal thermal management applications is of great significance for defending human against adverse climate conditions. However, the intrinsic low optical energy conservation of cotton in terms of human mid-infrared radiation and solar spectrum prevents it from realizing high-efficient thermal retention. Herein, by leveraging a facile technique involving polydopamine (PDA)-assisted ion deposition, we firmly embed silver nanoparticles onto cotton fibers, creating silver-nanoprocessed cotton fabrics (Ag-fabric) with high human mid-infrared reflectivity and superior water/wear resistance. Meanwhile, the localized surface plasmon resonance effect of the PDA and silver nanoparticles contributes to high solar spectrum absorptivity. The as-prepared Ag-fabric demonstrates nearly 2 °C higher temperature compared to unadorned cotton fabrics due to enhanced human mid-infrared radiation, and the outdoor tests show a temperature increase of average 8 °C when covering artificial skin. Moreover, the uniformly distributed silver nanoparticles on hierarchically assembled cotton fibers endow the Ag-fabric with desirable Joule heating performance (~ 40.7 °C at 1 V), self-cleaning capacity, and antibacterial properties, while maintaining breathability and comfort. These merits of the Ag-fabric present promising advantages to transfer natural cotton into commercially available thermal management wearables and eco-textiles. [ABSTRACT FROM AUTHOR]

Using steel slag (SS) as cementitious material and fine aggregate in concrete is an effective and environmental method for SS consumption and cost reduction. In this paper, SS was recycled in large volumes in concrete as partial cementitious material and fine aggregate. The compressive strength and reaction mechanism of cementitious material with different SS powder contents including 20%, 25%, 30%, and 35% were presented. The results indicated that 20% of SS powder improved the compressive strength by 34.57% and the hydration products were ettringite (AFt) and calcium silica hydrate(C-(A)-S–H). Furthermore, the mechanical and durability performance of concrete with SS as fine aggregate were investigated. When the SS substitution rate was 75%, the compressive strength was increased by 37.83%. The volume shrinkage rate and 28d-carbonation depth were reduced nearly by 64% for 90 days and 2.33 mm, respectively. The chloride ion penetration resistance reached the optimal grade Q–V and abrasion resistance was improved by nearly 24%. Along with the reduced CO2 by 210–294 kg/m3 and the decreased cost by 12.61 USD/m3, it is regarded as an effective method to consume steel slag. As such, this research provided a scientific and systematic basis for the large-scale disposal and utilization of industrial waste residues as well as recycled materials preparation. [ABSTRACT FROM AUTHOR]

Engineering slope stability issues typically exhibit the impact of deteriorating durability on the susceptibility of slopes to failure. A thorough investigation was essential to explore theoretical and experimental aspects of slope durability degradation and its implications on long-term stability. Hence, a durability model was developed to accommodate slope stabilization using reinforced concrete (RC) support structures. This model was grounded in classical durability principles for RC structures. Subsequently, a model test was conducted to compare the responses of a standard slope model with a weakened counterpart subjected to environmental impacts. According to the proposed methodology for slope durability and stability, a case study involving future durability and stability predictions was performed. It was found that the theoretical solutions for the carbonation or neutralization (CN) velocity, depth, and penetration time agreed well with model test results. The slope surface displacements of the weakened slope with deteriorating coefficients between 0.6 and 0.9 were 4 to 8 times those of the standard slope, demonstrating significant degradation in stability. The case study indicated a steady reduction in the safety factor, at a rate of 2.3 to 2.4‰ per year throughout the slope's service life. Finite-element-based predictions also suggested the potential for corrosion of slope anchor bolts within 20 years and breakage within 30 years, at an average rate of 7.5‰ per year in the ultimate bearing capacity. These findings highlight the need for timely maintenance and reinforcement interventions to ensure the long-term durability of operational slopes. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the potential use of wood ash as a cement additive. Four wood specimens from Yaoundé city of (Cameroon) were used namely: Sapelli, Iroko, Movingui and Padouk. Five mortar were produced, with cement substitutions of 0%, 5%, 10%, 15% and 20%. The fresh rheological, mechanical and hardened durability properties of various mortar were obtained after 7, 14, 28 and 56 days. The results showed that cement paste consistency and the cuing time increases with the addition of ash. At 28 days, the mortars obtained from the 5% and 15% Padouk and Movingui ash substitutes, respectively, showed optimum compressive strength (9%, 6%) and flexural strength (5%, 3%) compared with the control mortar. Due to continuous pozzolanic activity, this flexural gain is multiplied by 3 for Movingui mortar (9%) at 56 days. Compared with the 28-day and 56-day compressive strength results, there were increases of 5% and 4% respectively for the 5% and 15% ash substitutions in Padouk and Movingui mortars. Durability results were evaluated through absorption, which showed relatively identical rates in mortars containing ash from Padouk and Movingui wood, due to their water content for normal consistency. Chemical attack with H2SO2 and NaCl proved that the incorporation of ash improved the mortars' resistance to chemical attack. Thermal analyses and microscopic observations were performed with the optimum. [ABSTRACT FROM AUTHOR]

Expansive clays feature high compressibility and large swelling-shrinkage potential, which may cause significant damage to the infrastructures, including pavements. This study investigates the potential use of industrial waste ash generated from municipal solid waste incineration (MSWI) as a more sustainable treatment method to treat expansive soils compared to the use of conventional coal fly ash. A series of tests was conducted to study the mechanical, durability, and environmental performance of the MSWI fly ash in comparison with the coal fly ash. The study reveals that the compressive strength and resilient modulus of 20% MSWI fly ash treated sample increased to 0.86 MPa and 213 MPa respectively, depicting an increase of 150% and 240% of the control clay specimen. Results also indicate that MSWI treated expansive clay shows better performance during the soaked California bearing ratio (CBR) testings, moisture susceptibility and cyclic wetting–drying tests compared to coal fly ash treated samples. Microlevel investigations reveal that the influence of cation exchange is more decisive in the MSWI-treated clays due to the presence of higher Ca2+ ions, during the early stages, and the influence of hydration is stronger at the later stage of stabilisation. X-ray diffraction (XRD) results show that gismondine, albite, calcite, portlandite, andradite, and ettringite are the main crystalline phases formed during the stabilization. Heavy metal concentrations after the stabilisation are within the allowable limit defined by state regulations. Applying MSWI fly ash as a ground treatment for expansive clays can reduce the consumption of natural resources, promoting a "zero landfill" policy. [ABSTRACT FROM AUTHOR]

The impact of relative humidity on the formation of low-frictional interface in hydrogenated carbon nitride (CNx:H) coatings sliding against Si3N4 balls and the formation continuity was elucidated through friction tests conducted in both air and nitrogen atmospheres with controlled relative humidity levels. In air atmosphere, a carbonaceous tribolayer with a transformed structure from the initial CNx:H was formed on Si3N4 at less than the critical humidity that existed in 1.0–3.0% RH, resulting in low friction (μ < 0.05) and a low specific wear rate of the balls (< 2 × 10–9 mm3/N·m). In contrast, this tribolayer failed to form above 3.0% RH. In nitrogen atmosphere, within the 0.25–1.0% RH range, the tribolayer continued to form concurrently with wear progression, maintaining low friction for over 50,000 cycles. However, in less than this humidity range, the lifetime of low friction was limited owing to the tribolayer’s structural alteration. Thus, relative humidity influences not only the formation of the low-frictional interface but also the formation continuity. On the CNx:H friction surface, hydrogen, hydroxyl, and oxygen groups from environmental water and oxygen molecules continued to chemisorb owing to tribochemical reactions on the uppermost few nanometers during continuous low friction in a nitrogen atmosphere, while hydrogen content of CNx:H desorbed. This study experimentally confirmed the critical role of controlling relative humidity in tribological systems using CNx:H coatings to achieve low friction and improve its durability of low friction through the continuous formation of the low-frictional interface. [ABSTRACT FROM AUTHOR]

In this study, the effect of nano-CaCO3 on the durability of concrete was investigated by simulating the attack of semi-buried concrete structures in saline soil. Different nano-CaCO3 contents were used to enhance the durability of concrete. The durability of different areas of nano-CaCO3 modified concrete, partially exposed to sulfate solution, was evaluated, and a reliability analysis was conducted. The results indicated that appropriate nano-CaCO3 content can improve the durability of concrete. In this study, concrete with a nano-CaCO3 content of 1% exhibited the highest durability. The corrosion degrees of different areas of the nano-CaCO3 modified concrete partially exposed to the sulfate solution decreased in the following order: dry–wet transition areas (M area) > fully immersed areas (D area) > exposed air areas (T area). A sulfate chemical attack occurred inside the concrete in the dry–wet transition areas, while a sulfate physical attack occurred on the surface concrete. The predicted values of the model agreed well with the test results. The bivariate Wiener process can effectively describe the whole process of performance deterioration of nano-CaCO3 modified concrete. [ABSTRACT FROM AUTHOR]

Geopolymers with the inclusion of waste materials, viz., fly ash and slag, have been considered for various applications as a substitute for non-eco-friendly conventional binder, i.e., cement. Nevertheless, none of the studies have focused on soil stabilization using novel alkali-activated precursors—fly ash and calcium-rich eggshell powder with different curing temperatures. The objective of the present study is to analyze the effect of alkali-activated fly ash and eggshell powder on the durability of reference soft soil mix. The sodium silicate and sodium hydroxide solution were used to activate the precursors. The specimens, with varying percentages of precursors (10%, 20%, 30%, 40%, and 50%), were heated for 7 days at 25 °C, 50 °C, and 80 °C before subjecting to 12 wetting–drying cycles. The outcomes of the investigation show that the residual strength increases with the increase in geopolymer concentration following a similar pattern of 7-day compressive strength. A decrease in the weight loss of geopolymer-treated clay was detected for the specimens earlier cured at 50 °C. Further, the cost analysis suggested that the eggshell powder–fly ash geopolymer is a much cheaper binder than conventional cement concrete. [ABSTRACT FROM AUTHOR]

This study determines how untreated recycled concrete aggregates (URA), thermally treated recycled concrete aggregates (TRA), and recycled concrete aggregates developed through an integrated thermomechanical treatment process (TmRA) perform in concrete relative to each other. A concrete composed of 100% recycled aggregates (RCA) with Portland pozzolana cement has been successfully developed in the present study. The compressive strength, split tensile strength, flexural strength, fracture energy, and modulus of elasticity of TmRC is observed higher than URC by 18.62%, 8.20%, 40.72%, 24.18%, and 54.99%, and those TRC by 7.54%, 28.57%, 29.78%, 24.12%, and 34.35%, respectively. The split tensile strength, flexural strength, fracture energy, and modulus of elasticity of these concretes are strongly correlated with their compressive strength. TmRC material properties match NAC, standard requirements, and reported values closely. URC and TRC chloride-ion penetrations are around 3.51- and 2.42-times greater than TmRC. Among these concretes, only TmRC meets corrosion protection requirements like NAC. The abrasion resistance of TmRC is observed 52.03% greater than URC and 43.07% greater than that of TRC. TmRC has substantially lower sorptivity compared to URC and TRC and is close to NAC. TmRC has around 32.65% and 16.67% less weight loss in drying than URC and TRC, respectively. URC and TRC have around 1.99- and 1.82-times less abrasion resistance than TmRC. An optimal reduced adhered-mortar volume, the minimized porosity and microcracks, dense and uniform surface texture, strengthened interfacial transition zones leads the performance of TmRA superior to URA and TRA, and close to or superior to parent aggregates. [ABSTRACT FROM AUTHOR]

The abrasion testing process of topographically modified surfaces is investigated and their mechanical durability and wear characteristics are presented. The primary aim of the study is to demonstrate that a simple abrasion testing process carries a number of subtle complexities which are crucial for getting comparable results—i.e., sample area, abrasion duration, and presence of a microstructure. All of these factors can significantly alter the results of the testing process and have to be considered during comparison with other durability results. This study also demonstrates how topographically modified aluminum structures tend to restore their hydrophobicity after noticeable mechanical damage due to the natural oxidation process, whereas control samples stay in a hydrophilic state. The findings could be applied to improving the performance of wind or steam turbine blades. [ABSTRACT FROM AUTHOR]

In a randomized phase 2b trial (NCT03703102) for adult patients with moderate-to-severe atopic dermatitis (AD), treatment with the T cell rebalancing anti-OX40 receptor antibody rocatinlimab (AMG 451/KHK4083) led to significant improvements in clinical measurements versus placebo including whole-body Eczema Area and Severity Index (EASI) score. AD manifestations can impact variable anatomic regions, and involvement of the head and neck, a sensitive, hard-to-treat area, can negatively impact quality of life. In this post hoc analysis, we investigated response to rocatinlimab treatment across anatomic regions, including the head and neck. Least squares mean change from baseline to Week 56 in EASI score was analyzed by anatomic region (head and neck, trunk, upper extremities, or lower extremities) for patients with baseline moderate-to-severe AD in the respective anatomic region, using mixed models for repeated measures. Rocatinlimab groups were compared with placebo at Week 16. The proportion of patients achieving at least 75% reduction from baseline in EASI (EASI-75) was calculated. Probability of relapsing in EASI-75 during the off-treatment follow-up period (Weeks 36–56) was estimated using a Kaplan − Meier approach. At Week 16, decrease from baseline in mean EASI score was greater with all rocatinlimab regimens versus placebo across all anatomic regions for patients with baseline moderate-to-severe AD in the respective region (all P < 0.001). EASI scores continued to improve on treatment after Week 16 and were maintained during the off-treatment period across all regions. Among patients with baseline moderate-to-severe AD in the head and neck (n = 219; rocatinlimab, n = 174; placebo, n = 45), mean difference (rocatinlimab vs placebo) at Week 16 in LS mean percent change in head and neck EASI score ranged from − 30.4% to − 42.6% across treatment regimens. In patients who received rocatinlimab from the start of the trial, 47% − 71% achieved EASI-75 in the head and neck at Week 36. Among EASI-75 responders at Week 36, the probability of relapsing in EASI-75 in any region was low (< 25% in the head and neck) 20 weeks after treatment discontinuation until Week 56. Rocatinlimab treatment led to durable improvements in AD across multiple anatomic regions, including the sensitive head and neck region. [ABSTRACT FROM AUTHOR]

High-speed trains typically utilize helical gear transmissions, which significantly impact the bearing load capacity and fatigue service performance of the gearbox bearings. This paper focuses on the gearbox bearings, establishing dynamic models for both helical gear and herringbone gear transmissions in high-speed trains. The modeling particularly emphasizes the precision of the bearings at the gearbox's pinion and gear wheels. Using this model, a comparative analysis is conducted on the bearing loads and contact stresses of the gearbox bearings under uniform-speed operation between the two gear transmissions. The findings reveal that the helical gear transmission generates axial forces leading to severe load imbalance on the bearings at both sides of the large gear, and this imbalance intensifies with the increase in train speed. Consequently, this results in a significant increase in contact stress on the bearings on one side. The adoption of herringbone gear transmission effectively suppresses axial forces, resolving the load imbalance issue and substantially reducing the contact stress on the originally biased side of the bearings. The study demonstrates that employing herringbone gear transmission can significantly enhance the service performance of high-speed train gearbox bearings, thereby extending their service life. [ABSTRACT FROM AUTHOR]

Coatings serve as ideal protective films for mechanical systems, providing dependable as well as efficient lubrication because of their unique structure along with outstanding tribological characteristics. Inspired by the "bricks-and-mortar" structure, we prepared layered graphene oxide (GO) composite finishes strengthened with polyvinyl alcohol (PVA) and borax. Our study demonstrates that the tribological properties of the GO-based coating on 304 stainless steel (SS304) are potentially greatly affected through PVA, GO, and annealing. By optimizing the composition, we achieved the PVA40 wt%/GO0.01 wt%/borax composite coating, which exhibited the lowest average coefficient of friction (COF) of 0.021±0.003 (a 97.86% reduction compared to control SS304) with minimal wear and abrasion even in a water environment. We found that the enhanced mechanical characteristics as well as elastic recovery within the coating were attributed to the hydrogen bonds and cross-linking between PVA and borax, which led to stress distribution. Reduced friction was further aided by the formation of a hydrated layer at the friction interface. As a result, the coating demonstrated remarkable durability, maintaining a low COF during long sliding distances (576 m, 28,800 cycles, significantly longer than previously reported) without breaking. [ABSTRACT FROM AUTHOR]

This paper analyses the relations between intellectual capital (IC) and innovation. It links interest in the macro-effects of intellectual capital, typically found in cross-sectional studies on the effects of intellectual capital, to micro-studies of the performativity of intellectual capital. The former literature suffers from a lack of attention to the mechanisms that produce innovation, and the latter suffers from its focus on stabilising decisions in uncertain situations. The paper draws on the notion of perlocutionary performativity, which, in addition to suggesting that IC provokes effects, underlines that particular directions of these effects are uncertain, if not unknown. To show the mechanism through which perlocutions work, the paper draws on Butler's (1993; 1997) distinction between citability and ex-citability. According to this perspective, a citation of an IC corpus of expressions (citations, references, information) may be transformed, by being circulated (re-cited) and brought into a new potentially innovative arrangement, something which goes beyond (ex-cites) the cited reference. Over time, IC citations provoke innovation. Such a relation can be traced as a bushy form of innovation, which develops from a set of IC citations that have some durability in being reproduced regularly. The paper shows, through the analysis of two decades of reporting from Autostrade, that IC is both a set of disciplined citations of a particular kind of use value, a set of obligations to invest along this use value, and an unpredictable capitalisation of items of innovation. [ABSTRACT FROM AUTHOR]

This research study is performed on the self-compacting geopolymer concrete (SCGC) combining coal bottom ash (CBA) and metakaolin (MK) as a substitution for GGBFS alone and combined for analysing the fresh properties (slump flow, V-Funnel, and T50 flow), mechanical characteristics (compressive, splitting tensile and flexural strengths) and durability tests (permeability and sulfate attack test). Though, total 195 SCGC samples were made and tested for 28 days. It has been revealed that the consumption of CBA and MK as a substitution for GGBFS alone and combine in the production of SCGC is decreased the workability of SCGC while mechanical characteristics of SCGC are enhanced by utilizing CBA and MK as a substitution for GGBFS alone and combine up to 10%. In addition, the compressive, splitting tensile and flexural strengths were calculated by 59.40 MPa, 5.68 MPa, and 6.12 MPa while using the 5CBA5MK as a substitution for GGBFS in the production of SCGC after 28 days correspondingly. Furthermore, the permeability is decreased by growing the quantity of CBA and MK by the weight of GGBFS alone and jointly in the production of SCGC after 28 days. Besides, the minimum change in length of the SCGC specimen is recorded by 0.062 mm at 7.5MK7.5CBA while the maximum change in length is calculated by 0.11 mm at 10CBA10MK as a substitution for GGBFS at 180 days correspondingly. In addition, the embodied carbon is recorded reduce as the addition of CBA while it is getting higher when the accumulation of MK alone or combined with CBA in SCGC. Besides, response models for prediction were constructed and confirmed using ANOVA at an accuracy rate of 95%. The models' R2 fluctuated from 88 to 99%. It has been observed that the utilization of CBA and MK alone and together up to 10% as substitution for GGBFS in geopolymer concrete provides the best results therefore it is suggested for structural applications. [ABSTRACT FROM AUTHOR]

The growth of a thermally grown oxide (TGO) layer has been identified as a major driving force for the failure of environmental barrier coatings (EBCs). It is always desirable to reduce the TGO growth rate in order to achieve a highly durable EBC system. In this study, an Al2O3-modified Si bond coat was developed for EBC applications. Both a Yb2Si2O7/Si baseline EBC and a Yb2Si2O7/(Si-Al2O3)-modified EBC were deposited using the air plasma spray process. The TGO growth behavior and cycling life of the EBCs were evaluated at 1316 °C in a 90% H2O (g) + 10% air environment. The TGO growth rate in the baseline EBC is over four times faster than that of the modified EBC. The modified EBC survived 1000 cycles of steam testing without failure, while the baseline EBC has an average life of 576 cycles under identical conditions. The superior durability of the modified EBC can be attributed to the significantly reduced TGO growth rate. [ABSTRACT FROM AUTHOR]

The article presents a method for increasing the operating time of a cyclic unit by combining the operations of torch and gas-dynamic gunning through addition of magnesium briquetted flux. [ABSTRACT FROM AUTHOR]

Purpose: Power output at the moderate-to-heavy-intensity transition decreases during prolonged exercise, and resilience to this has been termed 'durability'. The purpose of this study was to assess the relationship between durability and the effect of prolonged exercise on severe-intensity performance, and explore intramuscular correlates of durability. Methods: On separate days, 13 well-trained cyclists and triathletes (V̇O2peak, 57.3 ± 4.8 mL kg−1 min−1; training volume, 12 ± 2.1 h week−1) undertook an incremental test and 5-min time trial (TT) to determine power output at the first ventilatory threshold (VT1) and severe-intensity performance, with and without 150-min of prior moderate-intensity cycling. A single resting vastus lateralis microbiopsy was obtained. Results: Prolonged exercise reduced power output at VT1 (211 ± 40 vs. 198 ± 39 W, ∆ -13 ± 16 W, ∆ -6 ± 7%, P = 0.013) and 5-min TT performance (333 ± 75 vs. 302 ± 63 W, ∆ -31 ± 41 W, ∆ -9 ± 10%, P = 0.017). The reduction in 5-min TT performance was significantly associated with durability of VT1 (rs = 0.719, P = 0.007). Durability of VT1 was not related to vastus lateralis carnosine content, citrate synthase activity, or complex I activity (P > 0.05). Conclusion: These data provide the first direct support that durability of the moderate-to-heavy-intensity transition is an important performance parameter, as more durable athletes exhibited smaller reductions in 5-min TT performance following prolonged exercise. We did not find relationships between durability and vastus lateralis carnosine content, citrate synthase activity, or complex I activity. [ABSTRACT FROM AUTHOR]

Purpose: The aims of this study were to: (i) describe the time course of the decrease in power output at the moderate-to-heavy intensity transition during prolonged exercise; (ii) investigate the association between durability of the moderate-to-heavy intensity transition and exercise capacity; and (iii) explore physiological correlates of durability of the moderate-to-heavy intensity transition. Methods: Twelve trained cyclists (age: 40 ± 8 y, V ˙ O2peak: 52.3 ± 5.2 mL·min−1·kg−1) performed an exhaustive cycling protocol involving alternating incremental exercise tests to determine power output at the moderate-to-heavy intensity transition via the first ventilatory threshold (VT1), and 30-min bouts at 90% of the power output at the previously estimated VT1 in the rested state. The individual time course of VT1 was modelled using linear and second-order polynomial functions, and time to a 5% decrease in VT1 (Δ5%VT1) was estimated using the best-fitting model. Results: Power output at VT1 decreased according to a second-order polynomial function in 11 of 12 participants. Time-to-task failure (234 ± 66 min) was correlated with Δ5%VT1 (139 ± 78 min, rs = 0.676, p = 0.016), and these were strongly correlated with absolute and relative rates of fat oxidation at specific exercise intensities measured during the incremental test performed in the rested state. Conclusions: These data: (i) identify a non-linear time course of decreases in the moderate-to-heavy intensity transition during prolonged exercise; (ii) support the importance of durability of the moderate-to-heavy intensity transition in prolonged exercise capacity; and (iii) suggest durability of the moderate-to-heavy intensity transition is related to fat oxidation rates. [ABSTRACT FROM AUTHOR]

A large number of waste tires are discarded every year. These waste tires will have a great impact on the environment. If they can be recycled, environmental and economic benefits can be obtained. In this paper, rubber powder is added to concrete, and a variety of analytical methods are used to study the effect of rubber powder on the performance of concrete. Experiments show that the slump of concrete decreases with the increase of rubber powder substitution rate, and the rheological performance results show that the friction force increases with the increase of rubber powder substitution rate. The compressive strength of concrete decreases with the increase of substitution rate. The results of ICP show that rubber powder will adsorb cations to affect cement hydration. Nanoindentation shows that the addition of rubber powder leads to the decrease of high-density hydration products. The results of SEM-EDS show that rubber powder will affect the Si/Ca of hydration products. The results of UPV and MIP are similar. The hydrophobicity of rubber powder and the poor compatibility with hydration products are the key factors affecting the durability of concrete. Because the rubber powder only needs to be ground to avoid the related process of cement, it can obtain good economic and environmental benefits. In practical engineering, rubber powder can be added appropriately. [ABSTRACT FROM AUTHOR]

Introduction: IncobotulinumtoxinA (Xeomin®) is used in the treatment of dynamic wrinkles and the aesthetic repositioning of facial structures. The duration of its muscular effect typically extends for around 4 months. However, the residual aesthetic benefit can be observed for a longer period. To date, the long-term aesthetic benefit of incobotulinumtoxinA in facial aesthetics has not been systematically evaluated. This study aimed to evaluate longitudinally the duration and aesthetic benefits of incobotulinumtoxinA in the treatment of the upper face in adult women. Methods: A quasi-experimental, evaluator-blind, clinical trial involving 28 adult women (30–60 years old) with facial movement lines, undergoing treatment of the upper face with incobotulinumtoxinA by two injectors, following an individualized protocol (ONE21 and glabellar contraction patterns) was performed. Participants were evaluated on the day of the intervention (day 0) and days 30, 120, 180, and 240, and subjected to standardized photographs. The following outcomes were evaluated blindly at each visit: Merz Aesthetics Facial Contraction Scale (MAS), GAIS (Global Aesthetic Improvement Scale), and patient satisfaction. Adverse effects were evaluated at each visit. Results: Participants ranged in age from 30 to 60 years, 93% were self-declared white, and most of their baseline MAS scores for dynamic lines were moderate and severe. All the parameters presented significative reduction from baseline until day 180. At day 240, the dynamic MAS scores were lower than baseline for forehead lines in 15.4% (95% confidence interval (CI) 0.8–30.0%) of the participants, for glabellar lines in 38.5% (95% CI 18.8–58.1%), and for crow's feet lines in 26.9% (95% CI 9.0–44.8%). Aesthetic improvement compared to baseline was identified in 35% (CI 95% 23‒50%) of the participants at day 240, and 62% (CI 95% 42‒81%) of the sample kept reporting some satisfaction with the procedure. Conclusion: The aesthetic treatment of the upper face with incobotulinumtoxinA demonstrates enduring clinical benefits, and patient satisfaction lasting up to 180 days in most participants. The length of efficacy, which exceeded those reported in the literature, may be attributed to the use of techniques based on individualized assessment such as ONE21 and glabellar patterns of contraction. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate 2-year efficacy, durability, and safety of faricimab in the TENAYA Japan subgroup and pooled global TENAYA/LUCERNE cohort of patients with neovascular age-related macular degeneration (nAMD). Methods: Subgroup analysis of TENAYA/LUCERNE (NCT03823287/NCT03823300): phase III, multicentre, randomised, active comparator–controlled, double-masked, non-inferiority trials. Treatment-naïve patients aged ≥ 50 years with nAMD were randomised (1:1) to intravitreal faricimab (6.0 mg up to every 16 weeks [Q16W] after 4 initial Q4W doses) or aflibercept (2.0 mg Q8W after 3 initial Q4W doses). Outcomes were assessed through year 2 for the TENAYA Japan subgroup (N = 133) and global pooled TENAYA/LUCERNE cohort (N = 1329). Results: Vision and anatomic improvements achieved with faricimab at year 1 were maintained over 2 years and were generally comparable between the TENAYA Japan subgroup and pooled TENAYA/LUCERNE cohort. Adjusted mean best-corrected visual acuity (BCVA) change from baseline at year 2 for the TENAYA Japan subgroup and global pooled TENAYA/LUCERNE cohort was +7.1 (3.7–10.5) and +4.4 (3.2–5.5) letters in the faricimab arm, respectively, and +5.2 (1.9–8.6) and +4.3 (3.1–5.4) letters in the aflibercept arm, respectively. At week 112, the proportion of faricimab-treated patients on Q16W dosing was 61.0% and 63.1% in the TENAYA Japan subgroup and pooled TENAYA/LUCERNE cohort. Faricimab was well tolerated through year 2. Conclusion: Year 2 TENAYA Japan subgroup findings for faricimab were generally consistent with the pooled global TENAYA/LUCERNE results in patients with nAMD. Vision and anatomical benefits with faricimab were similar to those with aflibercept but with fewer injections. [ABSTRACT FROM AUTHOR]

A methodology has been developed for the probabilistic assessment of durability indicators of metallurgical equipment according to strength criteria based on microstructural modeling of the stressed state of the material, the distinctive feature of which is the ability to consider its anisotropy and structural defects in the form of nonmetallic inclusions or the consequences of poor-quality heat treatment. This methodology can be used to make a reasonable choice of material for parts when designing equipment or developing the structure of repair cycles at the renovation stage for objects put in operation for the first time. [ABSTRACT FROM AUTHOR]

Metal oxide nanostructures (MONSTRs) have become popular in various fields. This study investigates the durability of MONSTRs synthesized through hot water treatment (HWT) using copper, aluminum, and zinc as the source metals of choice. The physical durability tests include pressure, scratch, and scotch tape adhesion tests, and chemical durability tests such as corrosion resistance tests, heat resistance, and solar exposure tests. Results showed that MONSTRs synthesized from HWT are highly durable under the tested conditions except for NaOH and HCl immersion tests for copper oxide and zinc oxide. The study concluded that HWT is a sustainable synthesis method for MONSTRs. [ABSTRACT FROM AUTHOR]

Up to 1.5wt% of Cr(III) salts (CrCl3, and Cr2O3) and Cr(VI) salts (Na2CrO4, and CaCr2O7) were incorporated into red mud-based geopolymers, respectively. The solidification/stabilization, compressive strength, and durability of the Cr-containing geopolymers were investigated. The experimental results indicate that the red mud-based geopolymer could effectively solidify/stabilize different types of Cr salts with solidification/stabilization rates of above 99.61%. Geopolymers are environmentally safe when the dosage of CaCr2O7 is ⩽ 1.0wt%, or the dosage of CrCl3, Cr2O3, and Na2CrO4 is ⩽ 1.5wt%, respectively. The effects of Cr salts on the compressive strength varies with the type and content of Cr salts. The freeze-thaw cycle is more destructive to geopolymer properties than sulfate attack or acid rain erosion. The solidification/stabilization of Cr is mainly attributed to the following reasons: a) The chemical binding of Cr is related to the formation of Cr-containing hydrates (eg, magnesiochromite ((Mg, Fe)(Cr, Al)2O4)) and doping into N-A-S-H gel and C-A-S-H gel framework; b) The physical effect is related to the encapsulation by the hydration products (e g, N-A-S-H gel and C-A-S-H gel). This study provides a reference for the treatment of hazardous Cr-containing wastes by solid waste-based geopolymers. [ABSTRACT FROM AUTHOR]

The sealing cup selection procedure for shaft surfaces during repairs is substantiated theoretically and tested practically. The procedure consists of justifying the diameters of the repair dimensions of the shafts based on wear data and selecting sealing cups for these dimensions according to the internal diameter in order to ensure the same tightness as for new connections. The practical application of the procedure is considered on a transmission output shaft connection. [ABSTRACT FROM AUTHOR]

Densification of biomass can significantly raise its volumetric calorific value, reduce its transportation costs, and create a more unified and stable biomass shape. Jojoba Simmondsia chinensis shrub is a desert-adapted shrub, and its cake is the solid byproduct of processing jojoba seeds for oil extraction and has a heating value of 15.344 MJ/kg. The study aimed to investigate the main and interaction effects of applied axial compression pressure, dwell time, and moisture content, on the relaxed density, dimensional stability or relaxation ratio, and durability of jojoba cake briquettes. The pure jojoba cake was compressed in a closed-end cylindrical die at room temperature of 27 ± 2 ∘ C at three levels of preset axial compression stress, P, 30, 35, and 40 MPa, two levels of dwell time, t, 5, and 10 s and four levels of material moisture content, mc, 20, 25, 30, and 35%wb. The findings showed that the applied axial compression pressure and moisture content significantly affected the relaxation ratio, relaxed density, and durability. Dwell time slightly affected the relaxed density and relaxation ratio but did not affect the briquette durability. Relaxed density was achieved within the range of 1001.353 and 1279.07 kg/m3, and the highest value was obtained at an applied pressure of 40 MPa, moisture content of 35%wb, and dwell time of 10 s. The desired lower relaxation ratio can be obtained with the optimal combinations of moisture content within the range of 30–35%wb and applied pressure within the range of 35–40 MPa. The high-quality briquette with an acceptable value of durability was found at the moisture content within the range of 30 and 35%wb at 40 MPa applied pressure. Stepwise linear regression analysis was conducted to determine the main and interaction effect of P, t, and mc on briquette durability, relaxation ratio, and relaxed density, and satisfying results were obtained. [ABSTRACT FROM AUTHOR]

This study aims to characterize the statistical durability under random strain loads for fatigue reliability prediction of a heavy leaf spring. Characterizing random data involving a probabilistic approach needs to be addressed in terms of defining applicable distribution as the strain data are random cyclic loading that leads to fatigue damage. In this study, random strain loads were extracted repetitively at a sampling rate of 500 Hz for 300 s per block of various road load profiles to obtain the probabilistic features (i.e., the parameters of location and scale, kurtosis, and root-mean-square values). The rainflow cycle counting technique was used to determine the strain-based fatigue life based on the linear damage rule. The load sequence effects computed the highest fatigue life with an estimated range of 1.66×104–3.16×104 cycles/block. The Akaike information criterion proposed that the Gumbel distribution is the most appropriate distribution to be used to model the durability of the leaf spring based on the captured strain signals. From the Gumbel distribution plot, the highest probability of fatigue failure was identified for the highway data in the range of 1.06×106–1.71×107 cycles/block with the probability of 0.72–0.99 since a smooth road surface produced low amplitudes in the strain data. In the reliability assessment, a mean cycle to failure was obtained in the range of 3.07×107–3.57×107 cycles/block, which is the highest value among other data. Hence, the probabilistic approach using the Gumbel probability plot for analyzing fatigue failure under random strain loads provides better statistical characterization in terms of the mean cycle to failure in reliability assessment. [ABSTRACT FROM AUTHOR]

As the world becomes increasingly aware of the devastating effects of climate change, the need for sustainable building materials that are both durable and environmentally friendly increases. Geopolymer and alkali-activated materials formed by a chemical reaction between an alkaline activator solution and an aluminosilicate source have gained popularity in recent years. The alkaline activator solution dissolves the aluminosilicate source, which then undergoes a polycondensation reaction to form a three-dimensional geopolymeric gel network. The development of this network ensures the strength and durability of the material. Today, this phenomenon of durability has been studied in detail to enable the development of superior construction materials, taking into account degradation mechanisms such as carbonation, leaching, shrinkage, fire, freezing and thawing, and exposure to aggressive environments (chlorides, acids, and sulphates). Although there are many unsolved problems in their engineering applications, slag-based alkali-activated materials appear to be more advantageous and are promising as alternative materials to ordinary Portland cement. First of all, it should not be ignored that the cure sensitivity is high in these systems due to compressive strength losses of up to 69%. Loss of strength of alkali-activated materials is considered an important indicator of degradation. In binary precursors, the presence of fly ash in slag can result in an improvement of over 10% in compressive strength of the binary-based alkali-activated materials after undergoing carbonation. The binary systems can provide superior resistance to many degradation mechanisms, especially exposure to high-temperature. The partial presence of class F fly ash in the slag-based precursor can overcome the poor ability of alkali-activated materials to withstand high temperatures. Due to the desired pore structure, alkali-activated materials may not be damaged even after 300 freeze–thaw cycles. Their superior permeability compared to cementitious counterparts can extend service life against chloride corrosion by more than 20 times. While traditional (ordinary Portland cement-based) concrete remains the most widely used material in construction, geopolymer concrete's superior performance makes it an increasingly emerging option for sustainable and long-lasting infrastructure. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the effects of prolonged intermittent cycling exercise on peak power output (PPO) and 6-min time-trial (6 min-TT) performance in elite and professional road cyclists. Moreover, the study aimed to determine whether changes in performance in the fatigued state could be predicted from substrate utilization during exercise and laboratory measures obtained in a fresh state. Methods: Twelve cyclists (age: 23 years [21;25]; body mass: 71.5 kg [66.7;76.8]; height: 181 cm [178;185]; V ˙ O2peak: 73.6 ml kg−1 min−1 [71.2;76.0]) completed a graded submaximal cycling test to determine lactate threshold (LT1), gross efficiency (GE), and maximal fat oxidation (MFO) as well as power output during a maximal 6 min-TT (MPO6 min) in a fresh condition. On a separate day, the cyclists completed a 4-h intermittent cycling protocol with a high CHO intake (100 g h−1). Substrate utilization and PPO was measured hourly during the protocol, which was followed by another 6 min-TT. Results: MPO6 min and PPO was reduced by 10% [4;15] and 6% [0;6], respectively, after the cycling protocol. These reductions were accompanied by reductions in the anaerobic energy contribution and V ˙ O2peak, whereas the average V ˙ O2 during the 6 min-TT was unchanged. Correlation analyses showed no strong associations between reductions in MPO6 min and PPO and laboratory measures (i.e., LT1, GE, MFO, V ˙ O2peak) obtained in the fresh condition. Additionally, fat oxidation rates during the cycling protocol were not related to changes in neither PPO nor MPO6 min. Conclusion: PPO and MPO6 min were reduced following prolonged intermittent cycling, but the magnitude of these reductions could not be predicted from laboratory measures obtained in the fresh condition. [ABSTRACT FROM AUTHOR]

Background: Presently, the proper disposal of E-waste is a major challenge for all nations. Portland cement and aggregates continue to play a major role in the construction industry's operations. Meanwhile, natural resources like gravel (aggregates) are becoming scarce. Thus, E-waste is now offering the building industry a chance to replace traditional aggregates. The main goal of the current study is to determine the highest amount of E-waste that may be replaced with 10-mm coarse aggregates with a nano-silica associated ternary blend in M-60 grade high-strength concrete while still maintaining the designed concrete's mechanical, durability, microstructural and workability characteristics. Results: When compared to normal concrete, concrete with 15% E-waste replacement maintained the design-required compressive, flexural and tensile strength properties. When the E-waste plastic component percentage is considerably high (15–30%), there is a significant decremental performance regarding the mechanical properties and the decremental rate is found to be in the range of 13–23%. Even the microstructure characteristics of concrete validate the mechanical performance of concrete. Nevertheless, the durability characteristics of E-waste incorporated concrete were found to be promising. Conclusions: The overall outcome of the study recommends 15% as the optimal replacement percentage of E-waste for conventional concrete, and it is recommended to adopt for real-time practices. [ABSTRACT FROM AUTHOR]

The presence of low-quality coarse aggregates and exposure to aggressive conditions are the two major problems with the durability of concrete. Therefore, an alternative concrete with enhanced properties to prevent fluid and ionic mobility compared to conventional concrete is needed. This study investigated the effects of main mix parameters on the transport characteristics and corrosion behavior of ultra-high performance fiber-reinforced concrete (UHPFRC). A set of 27 UHPFRC mixtures with different combinations of w/b ratio, cement, and silica fume contents, based on a 33-factorial experiment design, were prepared and tested for water permeability, chloride penetrability, electrical resistivity, chloride profile, and corrosion current density. The results showed that UHPFRC mixtures exhibited excellent durability properties characterized by negligible water penetration (< 15 mm), negligible and very low chloride permeability when the w/b ratio was 0.15 (< 100 Coulombs) and up to 0.2 (< 300 Coulombs), respectively, and very low chloride concentrations at the rebar level (0.03–0.18 wt.%). All resistivity values were within the range of 26.7–78.8 kΩ cm (> 20 kΩ cm) and pH values were 12.41–13.01, indicating the implausible likelihood of corrosion in the UHPFRC mixtures. This was confirmed through the corrosion current density measurements of reinforced UHPFRC specimens after 450 days of chloride exposure, which were below the critical limit for the corrosion initiation of reinforcing steel. Finally, the experimental data were statistically analyzed and fitted for all the listed tests, and models were developed for them using the regression analysis such that regression coefficients were within 0.90–0.99. [ABSTRACT FROM AUTHOR]

Engineered Cementitious Composites are a type of advanced building materials, which have excellent ductility and can significantly enhance structural resistance. However, the expensive material cost of ECC limits its engineering applications. This study investigated the potential of replacing commonly used silica (river) sand and imported PVA fibers with the local desert sand and PVA fibers, aiming at reducing the preparation cost of ECC and improving its economic benefits and sustainability. The mixture proportion was first optimized to obtain favorable strength and ductile enhancement, using a combination of single-factor test and theoretical calculation which mentioned the slurry coating thickness of fibers and desert sand. The potential of desert sand in preparing ECC was experimentally evaluated by comparing the uniaxial tension (compression) properties and microstructures of desert sand-based ECC (DS-ECC) and those of ordinary ECC. The results indicate that optimized DS-ECC can achieve satisfactory performance even when 100% fine aggregates are replaced by desert sand. It has comparable uniaxial tensile (compression) strengths to ordinary ECC but a significantly improved tensile ductility, with the ultimate tensile strain of about 5–8% and 3% at 7d and 28d curing ages, respectively. Meanwhile, the utilization of desert sand and local PVA fibers alone in ECC can substantially deliver a reduction of about 20–30% in material cost and an improvement in environmental impact. [ABSTRACT FROM AUTHOR]

This work studies the mechanical properties and durability of the ordinary Portland cement (OPC) and sulfoaluminate cement (SAC) binary system incorporated with metakaolin. Several tests are carried out to investigate the compressive and flexural strength, fresh performance including setting time and fluidity, resistance to sulfate attack, mass loss rate after 100 freeze-thaw cycles, and strength loss rate of the cement system with different ratios. The test results show that when the OPC and SAC are mixed with 7.5:2.5 and then the mixture is added with 10% metakaolin, the repairing and strengthening material with higher bonding strength can be prepared. After adding metakaolin, the interface accumulation form of the hydration product phase of SAC can be improved to combine with the existing hardened mortar to meet the requirements of repair and reinforcement. The system which has a short setting time, can be quickly repaired and strengthened and overcomes the defect of late strength shrinkage of SAC. At the same time, the sulfate attack resistance and frost resistance of composite mortar systems mixed with SAC and OPC can be enhanced by the added metakaolin. By referring to the ratio design method, the gradient design of the strength and setting time of the structural repairing reinforcing material can be performed to improve the strength and durability of the system of OPC and SAC, and realize the ecological design of cement materials. [ABSTRACT FROM AUTHOR]

The large amount of natural aggregate and cement in concrete production caused the exhaustion of natural resources and environmental impacts. Replacing the natural aggregate and cement using alternative materials in concrete production is necessary. The study aims to present the mechanical properties and durability of high-performance concrete produced with high-volume ground granulated blast furnace slag (GGBFS) and river sand/sea sand blended (S-HPC). The concrete mixtures were designed with a constant ratio of river sand and sea sand blending at 60:40 and various GGBFS content as partial cement replacement of 30%, 50%, and 70%. The mechanical strength and durability properties were observed up to 365 days of curing age. According to the findings, the S-HPC presented a good compressive strength achievement in a range of 73.2–83.9 MPa and UPV value of 4662–4860 m/s at 365 days of curing age. The washed sea sand concrete mixture presented a higher compressive strength and better durability performance than non-washed sea sand. Incorporating with GGBFS into S-HPC by up to 50% significantly improved concrete samples' mechanical performance, durability, and microstructure. Using GGBFS reduced the current records and delayed the initiation corrosion time of concrete samples. [ABSTRACT FROM AUTHOR]

This paper investigates the durability performance of mortars with varying replacement levels of dolostone or limestone filler (0–30% by mass) and the stability of mortars with dolostone filler for 2 years. Compressive strength, total porosity, capillary water absorption, and chloride migration coefficients were determined. Results show that compressive strength decreases and the total porosity increases with increasing filler content due to a dilution effect, regardless of the filler composition. The capillary water absorption and the chloride migration coefficients rise significantly for mortars with 20–30% filler. However, the dolostone filler cements have lower chloride coefficients than those with limestone blended cement. Volumetric stability assessments reveal no significant expansion, and XRD and FT-IR analyses suggest the formation of hydrotalcite-like phases. [ABSTRACT FROM AUTHOR]

Owing to their electrochromic performance, hierarchically structured transition-metal oxides have promising energy-saving device applications. In this study, nanosheet-structured nickel-cobalt (Ni-Co) oxide thin films were prepared via facile processes under simple solution conditions and were used as energy-saving electrochromic materials. As the growth time increased from 1.5 h to 8 h, the film thickness increased from ~ 0.7 μm to ~ 1.3 μm, and the porous nanosheet-like structures were more uniformly distributed throughout the thin film. At the 1000th cyclic voltammetry (CV) cycle (scan rate = 50 m/V), the in situ transmittance variation ( Δ T ) and optical density ( Δ OD ) of an Ni-Co oxide thin film grown for 8 h were ~ 49% and ~ 0.71 at a wavelength of 700 nm, respectively, which were better than those of samples grown for 1.5 h ( Δ T of ~ 26%, Δ OD of ~ 0.19) and 3 h ( Δ T of ~ 46%, Δ OD of ~ 0.61). However, the Ni-Co oxide thin-film samples grown for 1.5 h and 3 h had good electrochromic durability over 1000 cycles, with reversibility of 0.99. These Ni-Co oxide thin films exhibited tunable color modulation in the bleached and colored states, along with fast switching time (< 4 s) and excellent coloration memory effects. [ABSTRACT FROM AUTHOR]