Search

This study examined the corrosion inhibition of 304 stainless steel (304 SS) with fucoidan in 3.5% NaCl solution using both chemical and electrochemical methods, including mass loss as a chemical method and electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) as an electrochemical method. The fucoidan compound was verified and characterized by Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy, and morphology characteristics. The PP curves indicate that fucoidan was an effective corrosion inhibitor for 304 SS in 3.5% NaCl solutions, which indicates that the compound is a mixed-type inhibitor. It was shown that by adding the fucoidan inhibitor, the corrosion potential (Ecorr) and Tafel lines were slightly shifted. With the compound added, the value of the double-layer capacitance was reduced. In the case of 200 ppm, it reached maximum efficiencies of 81.7%. After studying its adsorption behavior on 304 SS, the Langmuir isotherm and chemical adsorption were concluded. It was necessary to compare the theoretical computations with the experimental findings using both density functional theory (DFT) and Monte Carlo simulations (MC). [ABSTRACT FROM AUTHOR]

Carbon-based electrodes have recently been most widely used in P-MFC due to their desirable properties such as biocompatibility, chemical stability, affordable price, corrosion resistance, and ease of regeneration. In general, carbon-based electrodes, particularly graphite, are produced using a complex process based on petroleum derivatives at very high temperatures. This study aims to produce electrodes from bio-pitch and charcoal powder as an alternative to graphite electrodes. The carbons used to manufacture the electrodes were obtained by the carbonisation of Robinia pseudoacacia and Azadirachta indica wood. These carbons were pulverised, sieved to 50 µm, and used as the raw materials for electrode manufacturing. The binder used was bio-pitch derived from coconut shells as the raw materials. The density and coking value of the bio-pitch revealed its potential as a good alternative to coal-tar pitch for electrode manufacturing. The electrodes were made by mixing 66.50% of each carbon powder and 33.50% of bio-pitch. The resulting mixture was moulded into a cylindrical tube 8 mm in diameter and 80 mm in length. The raw electrodes obtained were subjected to heat treatment at 800 °C or 1000 °C in an inert medium. The electrical resistivity obtained by the four-point method showed that N1000 has an electrical resistivity at least five times lower than all the electrodes developed and two times higher than that of G. Fourier-transform infrared spectroscopy (FTIR) was used to determine the compositional features of the samples and their surface roughness was characterised by atomic force microscopy (AFM). Charge transfer was determined by electrical impedance spectroscopy (EIS). The FTIR of the electrodes showed that N1000 has a spectrum that is more similar to that of G compared to the others. The EIS showed the high ionic mobility of the ions and therefore that N1000 has a higher charge transfer compared to G and the others. AFM analysis revealed that N1000 had the highest surface roughness in this study. [ABSTRACT FROM AUTHOR]

The presented study aims to reveal the effect of liquid temperature on cavitation-induced erosion of an Al-Mg alloy. An experimental work was conducted using a submerged cavitating waterjet to impact the specimen surface. For a certain cavitation number and a given standoff distance, different liquid temperatures were considered. Accordingly, a comprehensive comparison was implemented by inspecting the mass loss and surface morphology of the tested specimens. The results show that the cumulative mass loss increases continuously with the liquid temperature. A cavitation zone with an irregular profile becomes evident as the cavitation treatment proceeds. Increasing the temperature promotes the generation of cavitation bubbles. Large erosion pits are induced after severe material removal. The microhardness increases with the distance from the target surface. At a liquid temperature of 50°C, the microhardness fluctuates apparently with increasing the depth of indentation. [ABSTRACT FROM AUTHOR]

Copyright of Low-Carbon Materials & Green Construction is the property of Springer Nature 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.)

The formulation of ultra-high-performance concrete necessitates the use of a high cement content. The alkaline nature of cement makes it susceptible to acid attacks. In addition, its high C3A content causes its vulnerability to sulfate attack under the development of expansive ettringite, where porosity plays an important role. The main objective of this study was to figure out how mass loss and dimensional instability affected the rate of reaction and its relationship to acid concentration. It is noted that in contrast to sulfuric acid attack, sulfate attack on ultra-high-performance concrete (UHPC) is characterized by the accumulation of sulfate ions near the surface until reaching a critical concentration known as the threshold value. However, the reaction effect was not remarkable, as attributed to the extremely low porosity. The effect of curing was found to have a minimal influence on acid resistivity because it is a kind of spontaneous acid-base reaction that cannot be alleviated. In this research work, the UHPC's service life can be predicted when exposed to different concentrations of sulfuric acid. When comparing acid and sulfate attacks, the latter becomes negligible. Despite the use of silica fume and fly ash, the reactivity with sulfuric acid was found to occur spontaneously and rely on cement content and acid concentration. A concentration of 2.5% sulfuric acid is the threshold concentration after which a substantial change in the development of strength takes place. Both reactions were monitored on different types of samples over time using several techniques, such as XRD, TGA, and DSC and optical microscopy. [ABSTRACT FROM AUTHOR]

Erosion behavior at the interface of different layers is a critical consideration in pavement design and construction. Especially, this issue poses a particular challenge in dispersive clays, which are prone to excessive erosion. The current paper focuses on evaluating the effectiveness of nanoclay in stabilizing and mitigating the contact erosion behavior of dispersive clays. To do so, a range of experimental testing, including double hydrometer, pinhole, contact erosion and unconfined compressive strength (UCS) tests was employed. The findings revealed that incorporating 0.75% nanoclay content yielded significant results, leading to a remarkable 391% increase in the UCS, a notable 58% reduction in dispersivity potential (DP), a 53% decrease in eroded soil mass, and a 29% decrease in the dispersive clay settlement after a 28-day curing period. Additionally, new exponential correlations were successfully developed between soil dispersivity and contact erosion parameters (CEPs) with high coefficients of determination using over 50 contact erosion test results. To facilitate the estimation of CEPs, the values were made dimensionless including the ratios of eroded soil mass (m/m0), settlement (S/H), and void ratio (ef-e0/e0). Finally, scanning electron microscopy (SEM) and microstructural image processing (MIP) confirmed the filling between soil particles and the reduction of the number of voids due to nanoclay incorporation into dispersive clays. [ABSTRACT FROM AUTHOR]

The injection of CO2 into deep, unmineable coal seams is an effective strategy for reducing greenhouse gas emissions. At depths greater than 800 m, the carbon dioxide transitions to the supercritical state (Sc-CO2). This study investigated the complex interactions between Sc-CO2 and coal, which substantially affected the pore structure, mineralogy, and permeability of the coal. We used low-pressure nitrogen gas adsorption (LP-N2GA) to assess the impact of Sc-CO2 on the pore characteristics of the coal. X-ray diffraction (XRD) was also used to determine the causal factors. We performed comparative triaxial permeability tests before and after Sc-CO2 exposure to evaluate the changes in permeability for various coal types. Our findings suggested that Sc-CO2 exposure markedly increased the complexity of the coal pore structure, which in turn affects coal-rock permeability. Specifically, a 10-day exposure period resulted in considerable increases of 43.5% and 50.9% in the pore volume and the specific surface area, respectively, along with a slight increase of 0.01 nm in the average pore diameter. Furthermore, there were notable decreases in the contents of minerals such as kaolinite, calcite, and pyrite, with decreases of 1.5%, 2.8%, and 2.2%, respectively, whereas the quartz content increased by 3%, indicating that significant mineral dissolution influenced the pore structure. A significant positive correlation was observed between the loss of coal mass and the increase in permeability. The effects of Sc-CO2 were most pronounced in coals with low permeabilities, particularly during the initial phase of saturation. Subsequent saturation cycles and prolonged exposure resulted in a reduced rate for permeability enhancement, which eventually reached a plateau. This study underscores the critical role of Sc-CO2 in long-term geological CO2 storage and improved efficiency for coalbed methane production. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office 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.)

In the present study we investigated the combined effect of flow intermittence and wastewater treatment plant (WWTP) effluent on leaf litter decomposition in two Mediterranean streams with permanent and intermittent flow regimes. The litter decomposition experiment was performed using black poplar litter bags where we measured litter mass loss, fungal biomass, aquatic hyphomycete sporulation and species richness and C:N ratio. Afterwards, the remaining litter material from the different treatments was offered to the shredder Potamophylax latipennis in a microcosm laboratory experiment, and its growth and consumption rates were studied. We hypothesised that drying would decrease leaf litter decomposition in the permanent stream more than in the intermittent stream and that WWTP effluent would compensate for drying effects when both stressors interacted. The results indicated that drying has the greatest impact on the permanent stream, decreasing decomposition, aquatic hyphomycete species richness, and leaf litter quality. In the intermittent stream, WWTP effluent decreases aquatic hyphomycete species richness, but drying increases it, showing an opposing effect and a synergistic interaction. In the permanent stream drying provoked an increase in the shredder consumption rate. Thus, the expected more frequent intermittence in rivers under climate change may threaten the processing of organic matter. [ABSTRACT FROM AUTHOR]

Previous studies examining the influence of understory shrubs and light transmittance through the canopy (LT) (%) on seedling establishment of desired species and litter decomposition have reported inconsistent findings. Uncertainty still also remains about the effects of understory junipers (Juniperus oxycedrus L. subsp. oxycedrus) and LT on survival and growth of black pine (Pinus nigra Arnold.) seedlings as well as on litter decomposition across species' geographical range. Thus, this study aimed to examine the influence of understory junipers and LT on the growth and survival of black pine seedlings. Moreover, how junipers and LT affect litter decomposition was also monitored for eighteen months. Survival and growth of seedlings were most significantly affected by LT and understory junipers. LT and junipers negatively affected the survival of black pine seedlings. LT increased root-collar diameter (RCD) growth of the seedlings, while the RCD growth rate decreased with the presence of understory junipers. Moreover, the influences of LT and junipers on litter mass loss were mainly statistically significant; the presence of junipers and increasing LT in understory retarded litter decomposition. The findings may help our knowledge of ecological processes such as litter decomposition and seedling establishment in black pine forests. The results would also provide important guidance for evaluating the effects of overstory thinning (i.e., providing light to understory) and removing junipers on the ecological processes associated with litter decomposition and seedling recruitment in a black pine stand. [ABSTRACT FROM AUTHOR]

Abstract The use of bio-based biomass construction materials has the advantage of helping to reduce fossil energy demand, protecting the environment from carbon dioxide emission and reducing the production of non-degradable waste. This paper used resin-modified soy protein (SP) adhesive to combine rice straw stalks, and made straw-soy protein composites (SSPC) material. The physical properties, compressive behavior and stability during wetting drying cycles of SSPC were measured. Due to water evaporation, the SP matrix is full of connected pores, resulting to its physical properties of small density, high shrinkage ratio and low thermal conductivity, which are 0.24 g/cm3, 16.2%, and 0.065 W/(m•K), respectively. Adding straw is helpful to the physical properties of SP matrix, leading to an obvious decrease in shrinkage ratio and thermal conductivity of SSPC, which are 8.51% and 0.075 W/m•K. Furthermore, the compressive load–displacement curves of SSPC groups divide into two types: divergent and convergent. The compressive strength of divergent samples is decided by the critical displacement determined according to the convergent specimens. It shows that straw stalk proves the positive effect on the compressive property of SP matrix. As to the mass of SSPC samples during the wetting drying cycles, it drops apparently in the initial three cycles, and becomes negligible from the fifth cycle, meaning that the stability of SSPC during wetting drying cyclic process is quite good. The research result would be helpful for using SSPC as building material, especially as thermal insulation material.

Sweet corn was highly susceptible to senescence due to its elevated physiological metabolism after harvest, resulting in a decline in its edible quality. The aim of this study was to assess the effects of a cold storage insulation packaging box on the quality attributes of postharvest sweet corn (cv. 'Jinguan 218') during a simulated cold chain transportation period of 3 d and subsequent shelf life at room temperature (20 ℃) for 1 d. The control group involved cold storage at 4 ℃ to mimic refrigerated truck transportation. The results showed that the internal temperature of sweet corn packed in the cold storage insulation packaging box remained below 7 ℃ throughout the 3 d period. In comparison to the control group, the cold storage insulation packaging box effectively maintained the quality of sweet corn during cold chain transportation and shelf life, and delayed husk discoloration. The mass loss rate of sweet corn was reduced by 72.66% after 3 d of cold chain distribution using the packaging box, the soluble solid content was increased by 4.97%, and soluble sugar content was enhanced by 10.13%. Meanwhile, the activities of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in sweet corn packaged with the cold storage insulation packaging box were significantly (P

In this study, synthesis of cerium dioxide nanoparticles (CeO2 NPs) and preparation of chitosan-CeO2 nanocomposite (CH-CeO2 NC) were done and examined their inhibitive nature on mild steel surface in 1 mol/L HCl solution. Characterization was done through ultraviolet-visible (UV–Vis) and Fourier transform infrared (FT-IR) spectroscopy. Mass loss, electrochemical studies were used to determine the anticorrosive parameters of the prepared materials. Morphology, composition, and size were evaluated with scanning electron microscopy/energy dispersive spectrometry and X-ray diffraction. The inhibition efficiency was increased from 76.9% to 98.9% with the introduction of NPs in the CH. Atomic force microscopy and density functional theory results are in compliance with experimental studies and confirm the better performance of CH-CeO2 NC over chitosan.

Preplanetary nebulae (PPNe) are formed from mass-ejecting late-stage AGB stars. Much of the light from the star gets scattered or absorbed by dust particles, giving rise to the observed reflection nebula seen at visible and near-IR wavelengths. Precursors to planetary nebulae (PNe), PPNe generally have not yet undergone any ionization by UV radiation from the still-buried stellar core. Bipolar PPNe are a common form of observed PPNe. This study lays the groundwork for future dynamical studies by reconstructing the dust density distribution of a particularly symmetric bipolar PPN, M1-92 (Minkowski's Footprint, IRAS 19343+2926). For this purpose, we develop an efficient single-scattering radiative transfer model with corrections for double-scattering. Using a V-band image from the Hubble Space Telescope (HST), we infer the dust density profile and orientation of M1-92. These results indicate that M1-92's slowly expanding equatorial torus exhibits an outer radial cutoff in its density, which implicates the influence of a binary companion during the formation of the nebula. [ABSTRACT FROM AUTHOR]

We review the evolution of our understanding of the planetary nebulae phenomenon and their place in the scheme of stellar evolution. The historical steps leading to our current understanding of central star evolution and nebular formation are discussed. Recent optical imaging, X-ray, ultraviolet, infrared, millimeter wave, and radio observations have led to a much more complex picture of the structure of planetary nebulae. The optically bright regions have multiple shell structures (rims, shells, crowns, and haloes), which can be understood within the interacting winds framework. However, the physical mechanism responsible for bipolar and multipolar structures that emerged during the proto-planetary nebulae phase is yet to be identified. Our morphological classifications of planetary nebulae are hampered by the effects of sensitivity, orientation, and field-of-view coverage, and the fraction of bipolar or multipolar nebulae may be much higher than commonly assumed. The optically bright bipolar lobes may represent low-density, ionization-bounded cavities carved out of a neutral envelope by collimated fast winds. Planetary nebulae are sites of active synthesis of complex organic compounds, suggesting that planetary nebulae play a major role in the chemical enrichment of the Galaxy. Possible avenues of future advancement are discussed. [ABSTRACT FROM AUTHOR]

The major drawback of some magnesium alloys is their low corrosion resistance. Therefore, the evaluation of corrosion resistance is a critical factor in developing new alloys and surface treatments. The techniques employed for the determination of corrosion rate include mass loss assessment, hydrogen evolution, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). However, there are still difficulties in precisely estimating this parameter in Mg alloys. In this review, the reported applications, advantages, and disadvantages of the techniques mentioned above were analyzed. On the other hand, a large number of corrosion rate values reported for various Mg alloys in 3 different media (NaCl, Hanks´ solution and SBF), using mass loss, hydrogen evolution, and PP, were compared and analyzed. Generally, corrosion rates obtained from mass loss are higher than those obtained from hydrogen evolution. On the other hand, it is not possible to obtain correlations between corrosion rates obtained from PP and those obtained from mass loss and hydrogen evolution. Even more, dissimilar corrosion rate values are reported for the same alloy, implying that the measuring procedures are not well standardized. [ABSTRACT FROM AUTHOR]

The high-speed penetration of concrete targets by kinetic energy projectiles results in apparent mass loss, which blunts the nose of the projectile and decrease its penetration performance. The friction work between the projectile and the concrete target, the plastic deformation of the projectile, and the cutting of aggregates to the projectile significantly affect the mass loss of the projectile. To address these effects, a discrete iterative model is developed for the mass loss and nose shape evolution of the projectile by coupling three mechanisms based on the effect of temperature on strength. In the model, both friction work and plastic work increase the temperature of the projectile’s surface layer, thereby weakening the strength of this part and rendering it easier for mass loss to occur due to aggregate cutting. The model discretizes the projectile and penetration process with respect to the space and time dimensions, respectively. The mass loss and nose shape evolution of the projectile are obtained by iteratively calculating a point-by-point regression. The predicted depth of penetration (DOP), mass loss, and residual projectile profile are compared with experimental data to validate the model. The comparison shows satisfactory agreement between the calculated results and experimental data. Additionally, the deceleration, velocity, DOP, and mass loss during penetration are analyzed with respect to time. Finally, based on the model, the effects of projectile strength, caliber-radius-head (CRH), and concrete target strength on penetration are discussed. [ABSTRACT FROM AUTHOR]

Whenever a new material is replaced in concrete, some other tests other than strength and durability need to be carried out to validate the viability of the material replaced. This study aims to investigate the sustaining capacity of the light weight concrete manufactured with compost and Ground Granulated Blast Furnace Slag (GGBS) for M sand and cement respectively subjected to high temperature. Four concrete samples are tested, which includes the control specimen and three specimens are opted based on the optimum mix arrived from the strength and durability studies. Thermogravimetric Analysis (TGA) is done on the samples and they are heated up to 1,000 °C. For the specimens tested, the loss in mass with respect to the temperature is obtained. It is noted that the mass loss of the concrete samples with 15% GGBS along with compost at 0 & 10% is found lower than the control specimen. Also, from the loss in mass, the loss of chemically bound water and free CH content can be found, which aids in contributing strength to the concrete. For the concrete to be sustainable, compost can be replaced at 10% and GGBS at 15%. [ABSTRACT FROM AUTHOR]

Sweet corn was highly susceptible to senescence due to its elevated physiological metabolism after harvest, resulting in a decline in its edible quality. The aim of this study was to assess the effects of a cold storage insulation packaging box on the quality attributes of postharvest sweet corn (cv. 'Jinguan 218') during a simulated cold chain transportation period of 3 d and subsequent shelf life at room temperature (20 °C) for 1 d. The control group involved cold storage at 4 °C to mimic refrigerated truck transportation. The results showed that the internal temperature of sweet corn packed in the cold storage insulation packaging box remained below 7 °C throughout the 3 d period. In comparison to the control group, the cold storage insulation packaging box effectively maintained the quality of sweet corn during cold chain transportation and shelf life, and delayed husk discoloration. The mass loss rate of sweet corn was reduced by 72.66% after 3 d of cold chain distribution using the packaging box, the soluble solid content was increased by 4.97%, and soluble sugar content was enhanced by 10.13%. Meanwhile, the activities of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in sweet corn packaged with the cold storage insulation packaging box were significantly (P<0.05) higher than those in the control group, although the activity of superoxide dismutase (SOD) was inhibited by cold storage insulation packaging box. Therefore, the cold storage insulation packaging box demonstrated its ability to maintain the quality of sweet corn throughout cold chain logistics and shelf life. This work provides a technical basis for the preservation of sweet corn through cold storage packaging during post-harvest logistics and transportation. [ABSTRACT FROM AUTHOR]

Accelerated bridge construction (ABC) has emerged as a faster method of bridge construction. Reinforced concrete (RC) columns in bridges constructed using ABC methods remain vulnerable to corrosion, which impacts their performance during large earthquakes. Three specimens were constructed using ABC methods to investigate the effects of corrosion; two of these specimens were subjected to accelerated corrosion procedures to simulate moderate and severe corrosion levels. The longitudinal steel bars experienced 11% and 24% mass loss, while the steel spirals experienced 18% and 40% mass loss for moderately and severely corroded specimens, respectively. The severely corroded specimen experienced buckling of longitudinal bars at 5.0% drift ratio. Corrosion severity impacted column displacement capacity; the first reinforcing bar fractured at lower drift ratios in the corroded specimens, both of which experienced reduced displacement ductility and hysteretic energy dissipation. The importance of considering corrosion in evaluating seismic performance of RC bridges constructed using ABC methods is demonstrated. [ABSTRACT FROM AUTHOR]

The biological durability of ten wood species was determined on the basis of results from laboratory agar block tests. The experiment utilised two specimen formats: standard EN 113-2 specimens (15 × 25 × 50 mm) and mini-blocks (5 × 10 × 30 mm) exposed to two fungi (Coniophora puteana and Trametes versicolor) for varying incubation periods. Mini-block tests yield dissimilar outcomes compared to the European standard test at six, eight, ten or 16 weeks of incubation. This discrepancy extended to both durability classifications based on median percentage mass loss and those based on relative mass loss (x-values). It was therefore concluded that laboratory tests with miniaturised specimens are not advisable as a substitute for conventional durability classification assessments. [ABSTRACT FROM AUTHOR]

Background: This study presented a non-linear model to biologically describe the decomposition pattern, mass loss and nutrient release of four leaf litter species: Khaya senegalensis (African mahogany), Mangifera indica (Mango), Gmelina arborea (Beechwood), Eucalyptus camaldulensis (River red gum) and a mixture of the leaf litters using the standard litter bag technique. Objective: To explore different mathematical decomposition decay models in evaluating the decomposition rate and the relationship between mass loss and chemical parameters of some selected trees in Nigeria's northern Guinea savannah. Methodology: The experiment was a Completely Randomized Design with three replications. Fifteen litter bags were randomly placed in the field and retrieved at intervals of 0, 14, 28, 42, 56, 84, and 112 days (16 weeks). Three non-linear models were used to estimate the decomposition rate of the litter. Pearson correlation analysis was used to determine the relationship between mass loss and chemical composition. Results: Decomposition pattern gradually increased from 7 % up to 78.5 % by week 0 to 16 weeks. The leaf litter of Mangifera indica had the highest mass loss (62.9 %), followed by the litter mixture (44.0 %), Eucalyptus camaldulensis (43.6 %), Gmelina arborea (40.5 %) and Khaya senegalensis (39.3 %). Single exponential model (Adj R2=93.25-98.59%), double exponential model (Adj R2=87.93-98.98%), and three parameters asymptotic negative exponential model (Adj R2=93.82-98.84%), described the decomposition process efficiently. Correlation analysis of mass loss and chemical composition was highly significant (p ≤ 0.05), among all the leaf litter chemical properties, organic carbon, phosphorus, and nitrogen were the restraining factors. Implication: The mass loss was closely linked to the chemical properties of all the litter types. Among these properties, organic carbon and phosphorus were the limiting factors. Conclusion: We conclude that the single-leaf litter of Mangifera indica and Khaya senegalensis were superior in chemical composition, and decomposition than the mixed-leaf litter therefore they have the potential to enhancing soil fertility in the study area.

Manganese (Mn) is an essential cofactor for lignin-degrading enzymes and crucial for nutrient cycling and ecosystem functions. During litter decomposition, Mn may accumulate to fulfill the microbial demand for degrading recalcitrant substances such as lignin, which is reflected in the relative increase in Mn in decomposing litter compared with its initial amount. However, a global-scale quantification of the patterns and factors influencing Mn behavior at different decomposition stages has not been conducted. Thus, we systematically synthesized 1,466 observations from 53 publications to assess the global patterns and influencing factors of Mn accumulation in litter across various stages of decomposition. Our findings are as follows: (1) Mn primarily accumulated during litter decomposition on a global scale, despite some variability among stages. Notably, Mn accumulation was lower in the early decomposition stage (

After forest suppression in mining areas, deterioration of stocked tropical hardwoods occurs at different rates and levels. Prioritizing logs to avoid wastage is challenging because the wide interspecific variability of wood traits makes natural resistance unpredictable. This work aimed to compare the biodeterioration of four Amazonian hardwoods from a mining stockyard to arboreal termite attacks over six weeks under laboratory conditions. The woods' chemical composition, anatomy, basic density, and crystallinity were determined. Mass loss and visual diagnosis of the specimens supported the biodegradability analyses. The species showed a wide range of mass loss after six weeks: Jacaranda copaia (pará-pará) - 15,2 %; Pseudopiptadenia suaveolens (timborana) - 0,8 %; Aegiphila integrifolia (tamanqueira) - 5,2 %; and Euxylophora paraensis (pau amarelo) - 0,5 %. Biodegradation did not stabilize over time for the lowest-density species. The crystallinity indicated the initial degradation of amorphous wood components, followed by a non-selective feeding mechanism. Gathering all species, increased extractive and lignin levels, fiber wall thickness, and basic density favored the natural wood resistance, oppositely to large vessel elements. The much lower basic density of J. copaia explains its lowest natural resistance. Wall thickness, pore diameter, and density overcame chemical composition on wood biodegradability. Low-density hardwoods stocked in mining yards are a priority for proper destinations.

Liquid metal divertors are discussed as a potential alternative to divertor components made entirely of solid materials such as tungsten. However, liquid metal interaction with H isotope plasmas poses entirely new challenges, including the stability of the liquid surface. In this article, the interaction of low-temperature D plasmas with both free liquid tin surfaces, and the liquid metal confined in a capillary porous system (CPS) is presented. Free surfaces showed intolerable instabilities due to formation of gas bubbles in the melt, as opposed to a strong stabilizing effect of the CPS. A tendency of liquid tin to well up and entirely cover the surface of the CPS may be beneficial in terms of quickly re-establishing a tin surface after depletion by transient overloading. On the other hand, this appears to counteract efforts to fully suppress superficial bubble formation and bursting, and the resulting ejection of tin droplets by designing a CPS with very small pores.

While we have growing numbers of massive star observations, it remains unclear how efficient the key physical processes such as mass loss, convection and rotation are, or indeed how they impact each other. We reconcile this with detailed stellar evolution models, yet these models have their own drawbacks with necessary assumptions for 3-dimensional processes like rotation which need to be adapted into 1-dimensional models. The implementation of empirical mass-loss prescriptions in stellar evolution codes can lead to the extrapolation of base rates to unconstrained evolutionary stages leading to a range of uncertain fates. In short, there remain many free parameters and physical processes which need to be calibrated in order to align our theory better with upcoming observations. We have tested various processes such as mass loss and internal mixing, including rotational mixing and convective overshooting, against multiple observational constraints such as using eclipsing binaries, the Humphreys-Davidson limit, and the final masses of Wolf-Rayet stars, across a range of metallicities. In fact, we developed a method of disentangling the effects of mixing and mass loss in the 'Mass-Luminosity Plane' allowing direct calibration of these processes. In all cases, it is important to note that a combined appreciation for both stellar winds and internal mixing are important to reproduce observations. [ABSTRACT FROM AUTHOR]

Multi-material additive manufacturing using heterogeneous powders as raw materials is one of the important development directions of metal additive manufacturing technology. The evaporation behavior of heterogeneous powders in the selective laser melting (SLM) process has a significant influence on the accuracy of chemical composition control and the quality of the final product. In this paper, the fusion process of Fe20Mn (80 wt.% Fe and 20 wt.% Mn) heterogeneous powder, Fe and Mn elemental powders, and Fe20Mn pre-alloyed powder is numerically simulated using FLOW-3D® software and partially validated through SLM experimental results. The morphology and the characteristics of the flow field and temperature field in the melt pool for four kinds of powder materials are analyzed. The influence of the elemental evaporation behavior of different powders on the mass loss of the Mn element is discussed. The results show that the excessive accumulation of heat increases the maximum temperature of the melt pool, thus increasing mass loss. The Fe20Mn heterogeneous powder has a wider heat-affected zone and a higher peak value of temperature, nearly 400 K higher than that of the Fe20Mn pre-alloyed powders, which exhibits an intensive evaporation behavior. The mass loss of the Mn element obtained from the SLM experiment for Fe20Mn heterogeneous powders forming parts is more than the Fe20Mn pre-alloyed powders' forming parts for different laser powers, up to 17 wt.% at P = 120 W. This tendency is consistent with the numerical analysis of the effect of evaporation behavior of Fe–Mn heterogeneous powder during the SLM process. This study provides the necessary theoretical reference and process guidance for realizing the precise control of the SLM composition of a heterogeneous powder in multi-material additive manufacturing caused by evaporation behavior. [ABSTRACT FROM AUTHOR]

A promising method for additive manufacturing that makes it possible to produce intricate and personalized parts is selective laser melting (SLM). However, the mechanical properties of as-corroded SLM parts are still areas of concern. This research investigates the mechanical behavior of SLM parts that are exposed to a saline environment containing a 3.5% NaCl solution for varying lengths of time. The exposure times chosen for this study were 10 days, 20 days, and 30 days. The results reveal that the tensile strength of the parts is significantly affected by the duration of exposure. Additionally, the study also examined the influence of porosity on the corrosion behavior of the parts. The analysis included studying the mass loss of the parts over time, and a regression analysis was conducted to analyze the relationship between exposure time and mass loss. In addition, the utilization of scanning electron microscopy (SEM) and X-ray photo spectroscopy (XPS) techniques yielded valuable insights into the fundamental mechanisms accountable for the observed corrosion and mechanical behavior. It was found that the presence of corrosion products (i.e., oxide layer) and pitting contributed to the degradation of the SLM parts in the saline environment. This research emphasizes the importance of considering part thickness in the design of SLM components for corrosive environments and provides insights for enhancing their performance and durability. [ABSTRACT FROM AUTHOR]

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large‐scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass‐loss rates and stabilization factors of plant‐derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy‐to‐degrade components accumulate during early‐stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass‐loss rates and stabilization, notably in colder locations. Using TBI improved mass‐loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early‐stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models. [ABSTRACT FROM AUTHOR]

The mitigation influence of N1-(4-(dimethylamino)benzylidene)-N2-(2-((4-(dimethylamino)benzylidene)amino)ethyl)ethane1,2-diamine, (DBDB) against the corrosion of carbon steel and H2 production in 1.0 M HCl solution was studied. The experimental methods of mass loss, gasometry, potentiodynamic polarization, PDP, and electrochemical impedance spectroscopy, EIS, were utilized. The PDP data confirmed that the DBDB compound attitude is a mixed-type inhibitor. The protection efficacy rises with increasing the added amount of DBDB to reach 97% at 0.005 M concentration and 25 °C. The mitigation process was based on the adsorption of the DBDB molecules on the carbon steel obeying Langmuir's model. Some thermodynamic functions like Kads and ΔG°ads are computed and discussed. The negative sign of ΔG°ads proves the stability of the adsorbed DBDB molecules on the corroded metal surface. The ΔG°ads values vary between −38.70 and −35.13 kJ/mol explaining the existence of both the physical- and chemisorption mixed processes. The lowering in the Kads value with temperature confirms that the adsorption of DBDB compound is favorable at lower temperatures. Theoretical quantum calculations agreed with the experimental data. [ABSTRACT FROM AUTHOR]

In this study, five surfactants containing two pyridinium groups and one of which has a carbon chain of different lengths were synthesized in order to counteract the corrosion that occurs more rapidly on the metal surface in acidic environment. By using spectroscopic methods (FT-IR and NMR), the products' chemical structures were verified. Gravimetric measurements were then applied to assess how well they resisted metal corrosion. The experiment involved immersing metal plates in 1.0 M HCl solutions with varying inhibitor concentrations for a day at room temperature. The weight loss of each plate was then measured. By utilizing these weight losses, both corrosion rate and corrosion inhibition efficiency were calculated. As a result of the calculations, it was realized that their ability to inhibit metal corrosion gradually increased due to the decrease in corrosion rates as the long carbon chain in their structure increased. However, in order to determine the type of adsorption on the metal surface, which is a factor directly affecting their corrosion inhibition, a Langmuir adsorption isotherm study was performed, which was found to be compatible. In order to visually support that they protect the metal surface against corrosion, 1600-fold magnified surface images of the metal surfaces removed from the corrosion test were taken with an optical microscope camera. [ABSTRACT FROM AUTHOR]

• Fruit temperatures across the supply chain varied between 16 °C and 31 °C. • Temperature variations of fruits in upper and base cartons differed during cruising. • Carton positions in the ULD container showed no impact on product quality. • Superior product quality was obtained during storage at 16 °C compared to 21 °C. • Estimation of product mass loss using model based on temperature and humidity history. An air cargo supply chain for fresh mango was investigated from Thailand to France. Measurements of air temperature, air relative humidity, and fruit (peel) temperature were conducted using thermo-hygrometer data loggers in cartons. In a Unit Load Device (ULD) containing 148 cartons, twenty-seven instrumented cartons were placed at different positions to observe spatial and temporal temperature variations during 12 h cruising. At the destination, mango quality attributes were assessed at different time-points during 15-day storage at 16.1 °C and 21.6 °C. Throughout the supply chain, fruit temperatures ranged from 16.6 °C to 30.5 °C. During cruising, fruit temperatures in upper cartons remained almost constant, whereas base carton temperatures continuously decreased from 26.1 °C to 18.1 °C. Because of a short cruising period in comparison to a storage duration at the destination and proper ambient temperature condition during the experiment, carton position in the ULD had no discernible impact on fruit quality during storage. Fruit stored at 16.1 °C preserved superior fruit quality compared to 21.6 °C storage. For the same storage temperature, better quality of fruits stored in Thailand demonstrated the impact of air shipment on product degradation. The measured temperature and relative humidity evolutions were used as input parameters of a mass loss evolution model. A comparison with the measured data exhibited good agreement (RMSE < 1.8 % mass loss). Considering 10 % mass loss as a critical value, this model allows an estimation of the product shelf life based on a supply chain scenario. [ABSTRACT FROM AUTHOR]

Corrosion is one of the major causes of metallic pipes deterioration used in irrigation, such as galvanized steel. Its magnitude is directly linked to the quality of the water flowed by these pipes. Thus, the use of cathodic protection combined with pipe coating is used to achieve a greater protection. This study aimed to evaluate the effectiveness of using cathodic protection by the sacrificial anode method to reduce the mass loss, related to corrosion, in specimens of galvanized steel caused by fertigation solutions containing urea or potassium chloride, at 10 g L−1, using Zn, Al and Mg anodes, in addition to a control treatment, without protection. For this, immersion tests were conducted to obtain the mass loss per area, by simulating 10 years of operation. The results showed that with the use of sacrificial anodes it is possible to reduce the mass loss in galvanized steel caused by potassium chloride solutions for fertigation; however, this type of cathodic protection may not be effective in protecting urea-containing solutions from overall corrosion. The aluminum anode is the most suitable to use in solutions with high electrical conductivity, as it can reduce the mass loss caused by potassium chloride by up to 78% compared to the unprotected treatment. [ABSTRACT FROM AUTHOR]

Climate warming has been linked to shrub expansion in alpine regions and the decomposition of shrub leaf litter and subsequent release of nutrients has been proposed as a mechanism to facilitate shrub growth. We quantified the rate of alpine shrub leaf litter decomposition (measured as mass loss) over the course of a year in four locally occurring alpine shrub species that grow across four alpine summits. We measured a range of environmental attributes at the study sites, and via a standard litter bag approach, we evaluated the effects of site elevation, the depth of litter bag deployment, the removal time, the species‐specific leaf area (SLA) and the accumulated growing degree days at each site on the total per cent and rate of litter decomposition (as mass loss). The higher elevation sites were cooler with more snow days than the lower sites. Soil moisture was higher early in the snow‐free season at the higher elevation sites. Linear mixed effect models indicated no significant effects of elevation on total and rate of litter decomposition, but there were significant positive effects of deployment depth and removal time and a significant negative effect of species SLA. There were significant negative relationships between the rate of decomposition and growing degree days, as decomposition slows through time. The modelled mean rates of shrub litter decomposition for each species indicated that there would be more and faster decomposition if winter and early spring conditions were to persist for a whole year, compared with the modelled rates of average annual conditions persisting for a whole year. Our results indicate that Australian alpine shrub litter decomposes readily, with the highest rates of decomposition occurring soon after deployment, which in this study was after a snowy winter at the start of the growing season in spring. [ABSTRACT FROM AUTHOR]

This study aimed to dissect the thermal effects and kinetic behaviors of coal spontaneous combustion (CSC) under different heating rates (5, 10, 15, and 20°C/min). The charred coal, nonstick coal, and gas-fat coal were collected as coal samples, and thermogravimetric (TG)-differential scanning calorimeter (DSC) were performed. First, four characteristic temperatures were determined, and the CSC process was divided into four stages. Second, the characteristic temperatures, reaction stages, mass loss and thermal effects were investigated. The results indicated that as the characteristic temperatures increased, mass loss changed little, the TG-DSC curve peak shifted to high temperature, and the total heat release increased as the increases of heating rates. In addition, kinetic parameters of the conversion rate and activation energy was calculated. The apparent activation energies for the collected coal samples found by the Flynn-Wall-Ozawa method were 104.84, 95.51, and 129.84 kJ/mol, respectively, and those found when using the Kissinger method were 86.75, 78.90, and 110.54 kJ/mol, respectively. The results revealed that CSC occurred more difficultly in gas-fat coal than in charred coal. The results can provide theoretical support for the prediction and prevention of CSC in various applications. [ABSTRACT FROM AUTHOR]

The propagation of thermal runaway in a battery system is safety-critical in almost every application, such as electric vehicles or home storage. Abuse models can help to undestand propagation mechanisms and assist in designing safe battery systems, but need to be well-parametrized. Most of the heat during thermal runaway is released by venting that is why the characteristic of the vent flow plays an important part in the safety assessment. During venting, the cell generates a recoil force like a rocket, which depends on the flow speed and flow rate of the gas. This principle is used in this work to measure the velocity and mass flow rate of the vent gas. High-power and high-energy 18650 format lithium-ion batteries were overheated and the recoil and weight forces were measured to determine the venting parameter during thermal runaway. Our results show, that the linearized gas flow rate for the high-power and high-energy cell is 22.15 gs − 1 and 27.92 gs − 1 , respectively. The progress of the gas velocity differs between the two cell types and in case of the high-energy cell, it follows a single peak asymmetrical pattern with a peak of 398.5 ms − 1 , while the high-power cell shows a bumpy pattern with a maximum gas velocity of 260.9 ms − 1 . The developed test bench and gained results can contribute insights in the venting behavior, characterize venting, support safety assessments, simulations and pack design studies. [ABSTRACT FROM AUTHOR]

Wood, one of the materials predominantly employed in construction, possesses various advantageous properties alongside certain drawbacks, such as susceptibility to thermal degradation. To enhance wood fire resistance, one approach involves the application of flame retardants. This study compared the fire-retardant effectiveness of expandable graphite, bonded with water glass, as a coating for spruce wood against commercially available fire-retardant treatments. Spruce wood samples (Picea abies (L.) H. Karst) underwent treatment with three distinct retardants: expandable graphite in combination with water glass, Bochemit Antiflash, and Bochemit Pyro. The fire-technical characteristics of the samples were examined by a non-standard test method—a test with a radiant heat source. The experiment evaluated the fire-retardant properties by recording changes in sample mass, burning rate, and temperature difference. The best results among all flame retardants were achieved by expandable graphite in combination with water glass, in all evaluation criteria. Among all the flame retardants used, expandable graphite in combination with water glass achieved the best results in all evaluation criteria. [ABSTRACT FROM AUTHOR]

Hazelnut is a shelled fruit that is stored by drying and used as a snack or in industry. Since the hazelnut drying process is energy-intensive, there is a need for drying methods that will reduce the energy cost without lengthening the drying time. In this study, the effects of periodic drying of hazelnuts’ energy recovery, oil, and protein content, as well as mass losses, were studied. Fresh Tombul hazelnuts (Corylus avellana L.) with a diameter of Ø 15-16 mm were dried in a tunnel dryer over 16 different periods by adjusting the drying time inside and waiting time outside the oven until the moisture content reached 6%. Drying experiments were carried out at 45 ◦C and three different air velocities. The increase in air velocity resulted in a reduction in the periodic drying time between 10% and 36%. The optimum drying in terms of drying time and energy utilization was realized at 0.5 m/s air velocity, with a 1.5 h working time and 0.5 h waiting time. During this period, drying time increased by 19% and energy utilization was 69%. For periodic drying, the increase in oven working time causes a decrease in energy utilization, while the increase in waiting time causes an increase in energy utilization and drying time. Periodic drying had no negative effect on hazelnut oil and protein content. Periodic drying is a suitable option for saving energy during hazelnut drying. [ABSTRACT FROM AUTHOR]

The effect of mixing litter on decomposition has received considerable attention in terrestrial and aquatic (but rarely in both) ecosystems, with a striking lack of consensus in the obtained results. We studied the decomposition of a mixture of poplar and alder in three terrestrial: aquatic exposures to determine (1) if the effect of mixing litter on mass loss, associated decomposers (fungal biomass, sporulation rates, and richness), and detritivores (abundance, biomass, and richness of invertebrate shredders) differs between the stream (fully aquatic exposure) and when litter is exposed to a period of terrestrial exposure prior to immersion and (2) the effect of the mixture across exposure scenarios. The effect of the mixture was additive on mass loss and synergistic on decomposers and detritivores across exposure scenarios. Within scenarios, mass loss and decomposers showed synergistic effects only in the fully aquatic exposure, detritivores showed synergistic effects only when the period of terrestrial was shorter than the period of aquatic exposure, and when the period of terrestrial was equal to the period of aquatic exposure the effect of the mixture was additive on mass loss, decomposers, and detritivores. The species‐specific effects also differed among exposure scenarios. Alder affected poplar only when there was a period of terrestrial exposure, with increased sporulation rates and fungal richness in exposure 25:75, and increased mass loss in exposure 50:50. Poplar affected alder only under fully aquatic exposure, with increased mass loss. In conclusion, the synergistic effects of the mixture changed with a period of terrestrial exposure prior to immersion. These results provide a cross‐boundary perspective on the effect of mixing litter, showing a legacy effect of exposure to terrestrial decomposition on the fate of plant litter in aquatic ecosystems and highlighting the importance of also assessing the effect of mixing litter on the associated biota and not only on mass loss. [ABSTRACT FROM AUTHOR]

The present work represents the wear of contact systems (tribosystems) in boundary lubrication mode during reversible reciprocating motion. The investigated tribosystems are composed of non-standardized hypereutectic aluminium-silicon alloys. The samples, involved in the friction pairs, are from the alloys AlSi21Cu3CrMn, AlSi25Cu4Cr and AlSi25Cu5Cr, and the counterbodies have the compositions AlSi21Cu5MgCr and AlSi21Cu5Cr. The investigated alloys were modified with P and subjected to T6 heat treatment. Artificial aging was carried out under different parameters (temperature and holding time). Results were obtained for mass wear, wear rate and wear resistance of each sample, counterbody and overall for the tribosystem. [ABSTRACT FROM AUTHOR]

This paper aims to propose a short-distance water impact method to test the hydraulic erosion resistance of ultrahigh performance concrete materials (UHPC). The method used high-velocity water flow to simulate a complex hydraulic erosion environment, and an erosion zone was applied to evaluate the erosion resistance of materials. The erosion depth and mass loss of the specimens were tested. The results showed that a water pressure of about 2 MPa can be applied by short-distance water impact. At an impact time of 3 h and an impact distance of 1 cm, the erosion depth and mass loss of specimens were maximized. Thereinto, the erosion depth of mortar was 37.6% higher than that of UHPC. The mass loss of UHPC was 40.7% lower than that of mortar. Three indices for evaluating erosion resistance, including erosion rate expressed in %, erosion rate expressed in g/h , and erosion resistance strength, were compared. In addition, the erosion rate expressed in % could take into account the instantaneous state of the erosion process and reflect the deterioration trend with respect to impact time. According to the surface fitting, a predictive model between the erosion rate and impact condition was established. The variation trend of UHPC will be flat after a long period of erosion. The underwater method is compared, and the field test result is discussed. [ABSTRACT FROM AUTHOR]

Abstract Knowledge of the characteristics and durability of every wood species is essential so it can be better directed for the correct harnessing. In a wood rot field test, this work aimed to determine the natural durability of timber species from the Brazilian dry forest, Mimosa tenuiflora and Mimosa caesalpiniaefolia . The slats were buried in the ground up to half their length and distributed in the field according to a completely randomized experimental design. Annual assessments were performed to determine the deterioration rate. Furthermore, mass loss and condensed tannin content were quantified. The condensed tannin content found for the species was 4.40% for M. caesalpiniaefolia and 3.99% for M. tenuiflora . The results of 3 years of evaluation of the test make it possible to understand that both species presented durable wood, where M. caesalpiniaefolia presented a deterioration rate of 77.27%, while M. tenuiflora presented 66.27%, making them of high natural durability.

Torrefied biomass is a vital green energy source with applications in circular economies, addressing agricultural residue and rising energy demands. In this study, ML models were used to predict durability (%) and mass loss (%). Firstly, data was collected and preprocessed, and its distribution and correlation were analyzed. Gaussian Process Regression (GPR) and Ensemble Learning Trees (ELT) were then trained and tested on 80 % and 20 % of the data, respectively. Both machine learning models underwent optimization through Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) for feature selection and hyperparameter tuning. GPR-PSO demonstrates excellent accuracy in predicting durability (%), achieving a training R2 score of 0.9469 and an RMSE value of 0.0785. GPR-GA exhibits exceptional performance in predicting mass loss (%), achieving a training R2 value of 1 and an RMSE value of 9.7373e-05. The temperature and duration during torrefaction are crucial variables that are in line with the conclusions drawn from previous studies. GPR and ELT models effectively predict and optimize torrefied biomass quality, leading to enhanced energy density, mechanical properties, grindability, and storage stability. Additionally, they contribute to sustainable agriculture by reducing carbon emissions, improving cost-effectiveness, and aiding in the design and development of pelletizers. This optimization not only increases energy density and grindability but also enhances nutrient delivery efficiency, water retention, and reduces the carbon footprint. Consequently, these outcomes support biodiversity and promote sustainable agricultural, ecosystem, and environmental practices.