Search

The production of pulp and paper from recycled paper generates significant quantities of deinking paper sludge (DPS). This sludge contains a significant amount of organic matter (36%) as well as heavy metals such as Pb, Zn, and Cr. In this work, the incorporation of DPS (0%, 8%, 10%, and 12%) in the manufacture of clay bricks leads to valorization of this waste by showing that two of its contents considered problematic (organic matter and heavy metals) have several positive effects. It was found that the organic parts were transformed into pores after brick firing (850°C), which improved thermal insulation while keeping mechanical resistance in conformity with usual standards. For the heavy metals, which make DPS a hazardous waste, a leaching test was employed. The results show that these metals were trapped in the ceramic matrix after the firing of bricks at a high temperature, resulting in a final product that was not dangerous. Other tests were carried out on bricks with DPS to evaluate density, water absorption, shrinkage, loss on ignition, porosity, and microstructure in order to characterize this new product. It was concluded that DPS can be used in clay bricks as an asset for the formation of pores to enhance thermal insulation. The addition of DPS can be optimized at 10% to comply with the standard and not exceed the required values for shrinkage, water absorption, and loss on ignition. [ABSTRACT FROM AUTHOR]

The objective of this work is to produce an ecologically friendly material for use in Ivory Coast's construction sector in the future. These materials should have good thermal qualities and be flame resistant in addition to helping to achieve interior comfort. The fundamental components under consideration are freely accessible in Ivory Coast and include clay mortar as a fire retardant, potato starch as a binder, and recycled paper granules as a filler. The suggested ecologically friendly material's manufacturing process is fully described in detail. After conditioning, the team created multiple samples, taking into account that each test that the materials are put through requires various probe sizes for the thermal conductivity test, the reaction to fire test, and the flexural strength test. The best result regarding thermal conductivity of composites was obtained when 10 % clay is added in the mixture, namely between 0.057 … 0.068 W/(mK). During the ignitability tests the flame did not propagate to a height greater than 15 cm throughout the 60 s test time, so it can be concluded that the materials match minimally in the class E of reaction to fire. The flexural strength of tested materials was under 0.8 MPa.

The growing concern for environmental sustainability has created an urgent need for the development of innovative and environmentally friendly packaging materials. Among the various options available, clay-starch nanocomposites have emerged as a promising avenue for improving the barrier properties and mechanical strength of paper substrates. In this scientific paper the importance of clay-starch nanocomposite coatings on paper substrate and highlight the role of computer simulations, especially molecular dynamics, in elucidating their structural and functional properties. It has been shown that phyllosilicates with a layer charge < 0.4 electrons per stoichiometric unit can intercalate starch in the interlayer space, forming a barrier for water vapor in the covering layer. Phyllosilicates with a shell charge of > 0.4 electrons per stoichiometric unit were not able to intercalate starch. Thus, clay-starchnanocomposites can provide limited water vapor transfer rates and can be recommended asa promising material for dry food packaging.

Paper sludge is the water treatment waste, which produced during paper production. Paper sludge (PS) waste utilization is the common problem in the EU and internationally. According to the waste management directive No. 2008/98/EC, paper sludge waste should not be utilized in landfills. In the European Union, alone 93 million tons of PS generated yearly. Nowadays most of the paper sludge waste used as fuel for incineration power plants (up to 55 %). According to waste management legislation such waste management should be avoided as well. Very small portion (10 %) of PS is used in construction sector. In construction, paper sludge used as additive in concrete composite materials. Such legislation of waste management generates the motivation of this study. In this study authors propose to produce composite panels in which PS is the main material of composite. As the binding material, clay proposed due to its good binding properties and therefore its natural material. Such produced panels proposed to use it for sound absorption applications. To determine composites sound absorption coefficient standard ISO 10534-2 method was used. The sound absorption coefficient in different octave bands reached up to 0.59.

The Nordtest method evaluates the moisture buffer value (MBV) of materials that are being exposed to indoor air. The test simulates daily variations (high RH of 75% for 8 hours, low RH of 33% for 16 hours) in MBV, which in this context refers to the moisture uptake/release in the material when it is exposed to relative humidity (RH) in a square wave. We are looking for ways to increase clay plasterâs ability to buffer moisture. Which material has simultaneously a higher ability to buffer moisture and can be added to the clay plaster mixture? The recipe for the specimen included the following: waste paper (newspaper paper), glue (methylcellulose), clay and water. Our research showed that adding paper plaster mixture to the clay plaster mixture increases the moisture buffering ability of the plaster. The bigger the amount of added paper plaster, the better the plasterâs ability to buffer moisture.

The Nordtest method evaluates the moisture buffer value (MBV) of materials that are being exposed to indoor air. The test simulates daily variations (high RH of 75% for 8 hours, low RH of 33% for 16 hours) in MBV, which in this context refers to the moisture uptake/release in the material when it is exposed to relative humidity (RH) in a square wave. We are looking for ways to increase clay plaster's ability to buffer moisture. Which material has simultaneously a higher ability to buffer moisture and can be added to the clay plaster mixture? The recipe for the specimen included the following: waste paper (newspaper paper), glue (methylcellulose), clay and water. Our research showed that adding paper plaster mixture to the clay plaster mixture increases the moisture buffering ability of the plaster. The bigger the amount of added paper plaster, the better the plaster's ability to buffer moisture. [ABSTRACT FROM AUTHOR]

A polyaniline/clay combination was prepared via: 1) mixing polyaniline dispersion with clay; or 2) in situ polymerization of aniline in the presence of clay. To deliver electrical conductivity to cellulosic paper, the polyaniline/clay composition was applied to the paper surface by Meyer rod coating. The conductive paper was analyzed by Scanning Electron microscopy (SEM) and Fourier Transmission Infrared spectroscopy (FT-IR). For comparison purposes, conductive paper was also prepared by in situ polymerization of aniline in the presence of cellulosic fibers. The in-situ formed polyaniline was deposited on the fiber surface, and the polyaniline-deposited cellulosic fibers were made into paper sheets. It was found that at the same aniline content, paper surface coating with polyaniline/clay composition gave a much higher conductivity in comparison with the use of polyaniline-deposited cellulosic fibers for paper sheet formation.

Superhydrophobic materials have a lot of interesting potential applications. The self-cleaning property is a unique feature. Rendering the water-loving cellulosic paper superhydrophobic can open the door for value-added applications. Superhydrophobic paper is a fairly new area, and only very limited scientific publications are available in the literature. Among these publications, the topics on the use of mineral pigments in fabrication of superhydrophobic structures account for a large proportion. During the fabrication process, mineral pigments, e.g., silica, precipitated calcium carbonate, and clay, generally need to be hydrophobized, either directly or indirectly. Mineral pigments can be applied to cellulosic paper by surface treatment or wet-end filling, and good dispersabilities of these pigments are always highly demanded. A key mechanistic point is that by tunable particle packing or fabrication, mineral pigments may exhibit surface-roughening effects, which are critical for superhydrophobicity development. The roughening of a hydrophobic surface helps to enhance hydrophobicity. Possible concepts such as nano-structuring or controllable surface patterning of mineral pigments may help to improve superhydrophobicity. Environmental friendliness will also guide the scientific/technical development in this area.

The presence of intensely fissured soils is often found to relate to high geotechnical risks, such as landslide risk. This is especially the case of the Southern Apennines, Italy, where slopes formed of intensely fissured clays are frequently affected by landslides. The latter are generally triggered by rainfall infiltration, which takes place through the outcropping, unsaturated clayey soil cover. With the final aim of reducing landslide risk in areas covered by fissured clays, a detailed hydro-mechanical characterisation of these materials is required. While the behaviour of fully saturated fissured clays has been investigated in the last decade, only a few studies dealing with unsaturated, natural fissured clays are reported in the literature. The present paper aims to give a contribution toward filling this gap by extending an investigation campaign started a few years ago on the Paola Doce fissured clay outcropping on the Pisciolo slope (Southern Apennines, Italy). The physical properties of the material and some of its key micro- to meso-structural features are first analysed, the latter also based on Scanning Electron Microscope (SEM) micrographs of an undisturbed sample taken at 1.4 m depth on the Pisciolo slope, which is mainly formed of Paola Doce clay. Subsequently, water retention data of the soil are presented, which were obtained using both high-capacity tensiometers and the filter paper technique. These data were collected not only on undisturbed samples but also while subjecting the same material to drying paths. The results herein reported aim to make a link between the water retention behaviour of the Paola Doce clay sampled at Pisciolo and its fissured structure. [ABSTRACT FROM AUTHOR]

Dispersion coating may represent an alternative technology to extrusion coating, currently dominating the market of coated paper-based packaging. Being processed as inks, dispersion coatings can be applied with conventional equipment, achieving lower dry coat grammages. In this work, two styrene-butadiene-based (Tg1 ≅ 0 °C; Tg2 ≅ 15 °C) dispersion coatings filled with different amounts of kaolin were developed and rod-coated on two different paper substrates. The samples were tested for water, moisture, and grease barrier properties. Kaolin-containing formulations showed moisture barrier as low as 15 g/(m2∙day), as well as grease barrier higher than 24 h. The best formulation involved 20% by weight of kaolin, whereas higher amounts were detrimental for water barrier, beneficial for moisture barrier, and slightly detrimental for grease barrier properties. Benchmarked to two commercial grades, kaolin-filled coatings strongly improved grease barrier, yet achieving similar moisture barrier. [ABSTRACT FROM AUTHOR]

A polyaniline/clay combination was prepared via: 1) mixing polyaniline dispersion with clay; or 2) in situ polymerization of aniline in the presence of clay. To deliver electrical conductivity to cellulosic paper, the polyaniline/clay composition was applied to the paper surface by Meyer rod coating. The conductive paper was analyzed by Scanning Electron microscopy (SEM) and Fourier Transmission Infrared spectroscopy (FTIR). For comparison purposes, conductive paper was also prepared by in situ polymerization of aniline in the presence of cellulosic fibers. The insitu formed polyaniline was deposited on the fiber surface, and the polyaniline-deposited cellulosic fibers were made into paper sheets. It was found that at the same aniline content, paper surface coating with polyaniline/clay composition gave a much higher conductivity in comparison with the use of polyaniline-deposited cellulosic fibers for paper sheet formation. [ABSTRACT FROM AUTHOR]

Dispersion coatings are offered as alternative solutions to extrusion coating technology for paper-based packaging. In addition to providing barrier properties, waterborne dispersions may implement the processing and converting properties of coated substrates, which are of extreme interest for an effective transfer to the industry. In this work, styrene-butadiene-based aqueous dispersions were formulated considering different amounts of kaolin as pigment. The authors assessed the heat-seal ability, fold cracking resistance, and blocking tendency, comparing the results against commercial dispersion coating grades. Kaolin content dominated the sealing behavior of experimental formulations, changing the minimum heat-seal temperature from 80 °C to >140 °C for 0% and 60% kaolin solid content, respectively. On the contrary, commercial grades were mostly affected by temperature. Additionally, despite the low latex glass temperature (0 °C), experimental formulations generally showed little, if any, blocking. On the downside, increasing kaolin content eases fold cracking, showing a different magnitude according to fold direction and coat orientation yet achieving a higher moisture barrier compared to commercial grades for both folded and unfolded samples. [ABSTRACT FROM AUTHOR]

This study deals with the recovery of deinking sludge (DS) generated during waste paper recycling. The aim is to integrate this sludge in the fired-bricks formulation with different percentages. These mixtures are fired, and the study of the general aspect, loss on fire, and water absorption enables characterization of this material. Different compression tests are carried out on studied samples to characterize the strength and compare its performance to the standard. The mixtures' optimization and the elaboration conditions are the main objectives to obtain a new construction material with competitive performances conforming to the standards. [ABSTRACT FROM AUTHOR]

New compounds, called inhibitors, provide anti-yellowing effect for mechanical pulps and papers, when added to the coating formulation. The rheology of coating mixtures, which contain clay, ground calcium carbonate, starch, latex, inhibitors and other minor additives, affects to a certain extent the final quality of the coated paper. The purpose of this work is to investigate the effect of the total weight charge of inhibitors, when present between coating color ingredients, on the thixotropy and visco-elasticity of the mixture and other rheological properties. We also study the degree of interaction between inhibitor and coating ingredients using Transmission Electron Microscope (TEM) and water retention measurements.

Biochar (BC) is used as a soil amendment to enhance plant growth by improving mainly soil chemical and hydrophysical properties. In this work the effects of two types of BCs on soil water retention properties were analysed. The first type of BC was made from sugarcane bagasse. It was added to a clay "Shimajiri Maji" soil at an application rate of 3 w%. The second type of BC was made from paper fiber sludge and grain husks. It was added into a loam soil at rates of 3.6, and 7.3 w%. It was assumed that the effect of BC amendment will be more pronounced in coarse-grained soil than in fine-grained one. Therefore, the second type of BC was applied additionally in the silica sand, in a textured contrast material compared with the loam soil. The BC amendment caused statistically significant increase of water content in the transmission pores of the clay soil, in the storage pores of the loam soil, and in the macropores and the storage pores in the silica sand. Despite of the positive effect on soil water retention, statistically significant increase of available water capacity (AWC) was identified only in the loam soil with the larger BC amendment rate. Possible reasons are discussed. [ABSTRACT FROM AUTHOR]

In accordance with global estimations, approx. 15 million tons of residues are yearly generated from paper and pulp industry, which are traditionally used as biofuels or just disposed in landfills. However, residues composition and laws in force urge producers to search for new waste management strategies. From another point of view, the construction industry uses more than 33% of total natural resources, worldwide which has led several governments to limit the use of natural raw materials for building. In particular, fired brick industry produces yearly approx. 1600 billion bricks which represents millions of tons of natural resources consumption. Therefore, the goal is to contribute to reduce the amount of used clay. Thus, this paper explores the mineral and technological properties of brick made by using different percentages of paper pulp residues and fired at 900 °C. Results indicate that by increasing the replacement ratio, blend requires larger amounts of water which leads to a proportional increasing of shrinkage during drying. In spite of mineral transformations are not influenced by paper pulp residue, the porosity is linearly increased which leads to reduce compressive strength and thermal conductivity up to 30% for 20% of replacement ratio, in both cases. Thus, it is concluded that series made by replacing up to 10% show compressive strength above 5 MPa, water absorption beyond 20% and toxicity indexes meet the mandatory requirements. [ABSTRACT FROM AUTHOR]

Abstract: A series of ceramic based on (x) incinerated recycle paper - (80-x) cullet – 20 Kaolin clay (where 10×45 wt%) has successfully been made by slip casting technique followed by sintering at 1000°C. The actual composition of ceramic is analyzed using Energy Dispersive of X-Ray (EDAX) while the phase existence is determined using X-Ray Diffraction (XRD) technique. Their microstructural morphology is observed under Scanning Electron Microscope (SEM) and the physical properties are measured in term of their thermal shrinkage and hardness. It is found that the ceramic contain mostly of Silica and the phase is dominated by the existence of Quartz (SiO2), Wollastonite (CaSiO3) and Anorthite (Ca(Al2SiO8)). The SEM micrograph shows that the morphology is dominated by the existence of granular structure, and then become smoother as the cullet level is further increased. It is also found out that the thermal shrinkage is in the range 18% - 6.5% while the hardness is in the range of 152MPa- 1.463GPa depending on composition. [Copyright &y& Elsevier]

In order to clarify the suction characteristics of unsaturated clay under different conditions of water and salt, taking soil in western Jilin province, China as the research object, the suctions (matrix suction and osmotic suction) of samples with different water content, salt type, and salt content were determined by filter paper method. The results indicate that salt type and content have insignificant influence on the matrix suction. With the increase of water content, the matrix suction decreases at different rates in different suction regimes. When water content is constant, the osmotic suction increases with the increase of salt content, and under the condition of a constant salt content, the osmotic suction first increases and then decreases with the increase of ion concentration of the pore water, and can reach tens of MPa. The concept of suction equilibrium water content is proposed. When water content of sample is higher than this value, the magnitude of osmotic suction will always be greater than that of matrix suction. This indicates the necessity to consider osmotic suction in the presence or change of salt in soil. The applicability of the traditional models of matrix suction and osmotic suction in the full suction range of clay is discussed, and it is found that the traditional models cannot make a full explanation to the variation in suction. Based on the experimental data, an improved van Genuchten matrix suction model and an osmotic suction model, transformed by the Planck blackbody radiation formula, are proposed. [ABSTRACT FROM AUTHOR]

The effect of percentage solids content, coating film thickness and plastic pigment on mechanical properties of coated paper was studied. The results showed that the tensile strength, TEA, stretch and tensile stiffness were improved as the percentage solids content and the coating film thickness were increased. Bending stiffness slightly increased when solids content was increased and showed higher values on increasing the coating film thickness. The addition of plastic pigment to both clay based and GCC based coating mixtures improved the mechanical properties considered in this study. Although tensile strength and tensile stiffness increased with the addition of plastic pigment of smaller particle size, stretch and TEA showed a reverse trend. [ABSTRACT FROM AUTHOR]

Abstract: Production of porous anorthite refractory insulating firebricks from mixtures of two different clays (K244 clay and fireclay), recycled paper processing waste and sawdust addition are investigated. Suitability of alkali-containing-clay, low-alkali fireclay, pore-making paper waste and sawdust in the products was evaluated. Prepared slurry mixtures were shaped, dried and fired. Highly porous anorthite ceramics from the mixtures with up to 30% sawdust addition were successfully produced. Physical properties such as bulk density, apparent porosity, percent linear change were investigated as well as the mechanical strengths and thermal conductivity values of the samples. Thermal conductivities of the samples produced from fireclay and recycled paper waste decreased from 0.25W/mK (1.12g/cm3) to 0.13W/mK (0.64g/cm3) with decreasing density. Samples were stable at high temperatures up to 1100°C, and their cold strength was sufficiently high. The porous anorthite ceramics produced in this study can be used for insulation in high temperature applications. [Copyright &y& Elsevier]

Abstract: Glass-ceramics were prepared from mixtures of wastes generated from refining of silica sand and kaolin clay (Kira) and paper sludge ash. Kira and paper sludge ash were mixed in mass ratios of 55/45. The mixtures were melted at 1400°C and quenched in water to obtain glasses. The quenched glasses were ground to <48 mesh and used to prepare glass-ceramics. Crystallization of the parent glass occurred above 950°C, producing quartz solid solution at 1000°C and cristobalite at 1100°C as the major crystalline phases. The color of the glass-ceramics is white or slightly pale yellow. The four-point bending strengths of the as-fired glass-ceramics range from 63 to 66MPa and the Vickers microhardness values from 6.0 to 6.4GPa. The average linear thermal expansion coefficients of the glass-ceramics range from 6.3×10−6 /°C to 8.1×10−6 /°C (30–380°C) and show non-linearity around the phase transition temperatures of quartz and cristobalite. The chemical durability of the resulting glass-ceramics is excellent in alkali but poor in acid solution. The glass-ceramics show rather better performance than commercial glass-ceramics even when prepared solely from wastes starting materials. [Copyright &y& Elsevier]

Abstract: Large numbers of soil samples are routinely analyzed using methylene blue (MB) titration to determine clay content. Although, the MB filter paper spot test titration is simple, it is labor-intensive, subjective, and leaves no record for subsequent re-examination. Preliminary thermometric monitoring of the titration indicated a switch from endothermic to exothermic reaction during titration. We examined this nearly universal property of physicochemical processes as a potential replacement method to automate the MB clay titration, making use of literature data. We translated the isothermal enthalipmetric titration of montmorillonite using MB by Rytwo and Ruiz-Hitzky to an adiabatic thermometric titration (2003). The plot of temperature versus titrant volume gave two intersecting linear segments dependent on the titrated percentage of the clay''s cation exchange capacity (CEC). The MB filter paper spot test endpoint reflects the first excess MB that persists in the solid suspension, which also happens to be a function of the clay''s CEC. The spot test endpoint is correlated to the thermometric indicator point and, for montmorillonite, the two are related by an exact factor of two. Although this factor will naturally be dependent on the clay minerals in the samples, the analyses show that the thermometric indicator titration method is a viable replacement for the spot test. The proposed automation is commonplace as it is practiced with other types of titrations. [Copyright &y& Elsevier]

Background: Mastery of fine motor skills is indispensable in daily life. The purpose of this study was to examine the improvement of fine motor skills after playing plasticine and clay. This study is an experiment with a sample of 40 children divided into 2 groups. One group got the treatment of playing plasticine and the other got the treatment of playing clay. Each group was treated for two hours of play each week at a frequency of three times a week. The present research was accomplished in 2 months. Instruments used for fine motor skills were paper cutting precision, coloring patterned images, bolding letters, and skills to make objects using plasticine and clay. The data is analyzed using a t-test with a significance level of 5%. The results showed that there was an increase in fine motor skills in both groups of playing plasticine and clay with P < 0.05. [ABSTRACT FROM AUTHOR]

This document discusses a research paper that explores the effects of viscoplasticity and strain softening on the stress-strain characteristics of saturated clays and plastic silts. The paper raises questions about the behavior of these materials in laboratory tests versus their behavior in situ. It also discusses the effects of anisotropy on the undrained shear behavior of clays and silts, presenting data from various tests to illustrate this behavior. The document highlights the behavior of quick clays under shear stress, noting that failure occurs at small axial strains followed by a rapid drop in shear stress and a gradual loss of strength. It emphasizes the importance of matching the rate of shear in laboratory tests to the rates that occur in the field and concludes that stability can be improved through ground treatment methods or supporting structures on piles. [Extracted from the article]

Interactions between soil, fluids (e.g., water), and structures are intrinsic to most geotechnical problems. However, these can be extremely complex and further understanding is needed in this field. Soil–water–structure interactions can be studied on many different scales (micro to macro) and perspectives (experimental, numerical, and theoretical). In any case, the consequences of these interactions control soil behaviour, the stability of civil infrastructure, and, ultimately, the safety of our communities. This Special Issue consists of five papers (three research papers and two literature reviews) that highlight the importance of soil–water–structure interactions in a broad range of different applications. The topics addressed in the research contributions include (a) the performance of shallow footings under oblique loads, (b) the assessment of nonlinear base-isolated building systems under dynamic loading, and (c) the applicability of lightweight materials as fill for retaining wall systems. The other innovative papers, on the other hand, provide comprehensive reviews on (d) the role of the clay content in the interface characteristics between sand–clay mixtures and structures and (e) the latest developments in the understanding and measurements of the Atterberg limits. [ABSTRACT FROM AUTHOR]

A novel Mg-Al metal oxide has been successfully synthesized by the calcination of hierarchical porous Mg-Al hydrotalcite clay obtained by using filter paper as a template under hydrothermal conditions. Various characterizations of the obtained nanoscale oxide particles verified the uniform dispersion of Mg-Al metal oxides on the filter paper fiber, which had a size of 2–20 nm and a highest specific surface area (SSA) of 178.84 m2/g. Structural characterization revealed that the as-prepared Mg-Al metal oxides preserved the tubular morphology of the filter paper fibers. Further experiments showed that the as-synthesized Mg-Al metal oxides, present at concentrations of 0.3 g/L, could efficiently remove sulfonated lignite from oilfield wastewater (initial concentration of 200 mg/L) in a neutral environment (pH = 7) at a temperature of 298 K. An investigation of the reaction kinetics found that the adsorption process of sulfonated lignite (SL) on biomorphic Mg-Al metal oxides fits a Langmuir adsorption model and pseudo-second-order rate equation. Thermodynamic calculations propose that the adsorption of sulfonated lignite was spontaneous, endothermic, and a thermodynamically feasible process.

A novel Mg-Al metal oxide has been successfully synthesized by the calcination of hierarchical porous Mg-Al hydrotalcite clay obtained by using filter paper as a template under hydrothermal conditions. Various characterizations of the obtained nanoscale oxide particles verified the uniform dispersion of Mg-Al metal oxides on the filter paper fiber, which had a size of 2–20 nm and a highest specific surface area (SSA) of 178.84 m2/g. Structural characterization revealed that the as-prepared Mg-Al metal oxides preserved the tubular morphology of the filter paper fibers. Further experiments showed that the as-synthesized Mg-Al metal oxides, present at concentrations of 0.3 g/L, could efficiently remove sulfonated lignite from oilfield wastewater (initial concentration of 200 mg/L) in a neutral environment (pH = 7) at a temperature of 298 K. An investigation of the reaction kinetics found that the adsorption process of sulfonated lignite (SL) on biomorphic Mg-Al metal oxides fits a Langmuir adsorption model and pseudo-second-order rate equation. Thermodynamic calculations propose that the adsorption of sulfonated lignite was spontaneous, endothermic, and a thermodynamically feasible process. [ABSTRACT FROM AUTHOR]

This document is a discussion of a research paper titled "Numerical Study of the Effect of Ground Improvement on Basal Heave Stability for Deep Excavations in Normally Consolidated Clays" by Ari Surya Abdi and Chang-Yu Ou. The authors conducted a three-dimensional finite-element method analysis to investigate the impact of ground improvement on the stability of deep excavations in soft clays. They proposed a modified Terzaghi's method based on their findings. However, the discussion raises concerns about the reliability of the authors' numerical simulation results and suggests the need for validation through field or experimental data. It also questions the use of an elastic-perfectly plastic Mohr-Coulomb model and the absence of mention of dewatering in the original paper. The discussion further examines the displacement patterns and deflection profiles of retaining walls during excavation. The author requests a response from the original authors. [Extracted from the article]

This document is a closure to a paper titled "Effect of Viscoplasticity on Localization in Saturated Clays and Plastic Silts." The original paper presented a numerical study on the effects of viscoplasticity on localization processes in sensitive clays and plastic silts. The closure addresses comments made by a discusser, discussing various issues related to soil behavior, strain rates, and the interpretation of laboratory and field data. The authors emphasize the importance of understanding strain rate effects in interpreting field observations, case histories, and laboratory and in situ test measurements. They also clarify terminology and provide insights into the limitations and future research needs of the original study. [Extracted from the article]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing 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.)

Ion-adsorption-type rare earth ores (IRE-ores) are a vital source of rare earth elements globally. The percolation properties of the ore body significantly determine the ease of rare earth extraction using in situ leaching processes. This paper investigates the interactions among clay particles in ion-adsorption-type rare earth ores within aqueous solutions, utilizing methods such as mineral particle aggregation and settling and acid–base adsorption on mineral surfaces. Based on these analyses, this paper elucidates the influence of solution properties on the percolation process of ion-type rare earth ores during leaching. The results indicate that the electrostatic attraction between minerals in aqueous solutions is pronounced, enhancing the interaction and resulting in a notable instability of the aggregates. The aggregation of minerals impacts the viscous effect of water bound to the mineral surface on the solution, thereby affecting the percolation rate. Extremely low concentrations of SO42− and CH3COO− can act as surface modifiers, reducing the electrostatic attraction between particles and consequently increasing the leaching percolation rate. [ABSTRACT FROM AUTHOR]

Studies on recycled materials emerged during recent years. This paper investigates samples' sound absorption properties for panels fabricated of a mixture of paper sludge (PS) and clay mixture. PS was the core material. The sound absorption was measured. We also consider the influence of an air gap between panels and rigid backing. Different air gaps (50, 100, 150, 200 mm) simulate existing acoustic panel systems. Finally, the PS and clay composite panel sound absorption coefficients are compared to those for a typical commercial absorptive ceiling panel. The average sound absorption coefficient of PS-clay composite panels (αavg. in the frequency range from 250 to 1600 Hz) was up to 0.55. The resulting average sound absorption coefficient of panels made of recycled (but unfinished) materials is even somewhat higher than for the finished commercial (finished) acoustic panel (αavg. = 0.51). [ABSTRACT FROM AUTHOR]

For the case that corresponds to removal of smaller surcharge, HT ht in Fig. Considering the scatter in the HT ht data, 0.6-1.0, evident in Fig. 5(a) show that, on average, the HT ht values from the Arup study were about 1.5 times the HT ht values from the original paper. 1 of the original paper for estimating the equivalent preconsolidation stress, HT ht , is also not applicable. [Extracted from the article]

Clogging is a major geohazards risk in mechanized tunnelling through cohesive soils. Clay clogging results from the high adhesion between the clay and metal. Based on the water film theory and Reynolds fluid equation, the interfacial adhesion between metal and soil is simplified in this study as viscous hydrodynamic behavior between planes. Considering the influence of capillary force and the viscous force of water film at the interface between metal and soil, a theoretical calculation model of interfacial adhesion between metal and soil is established. The influence of water film thickness and separation rate on the interfacial adhesion between metal and soil is qualitatively analyzed. Then, the adhesion stress between the clay and the metal surface was tested with a pullout test and the influence of moisture content, pullout rates and types of clay minerals on the adhesion stress was analyzed. Finally, the calculation model of adhesion force was compared with the experimental results. The calculation model of soil adhesion stress established in this paper can quantitatively describe the relationship between soil adhesion force and moisture content and can also qualitatively reveal the influence mechanism of soil moisture content on adhesion stress. [ABSTRACT FROM AUTHOR]

The conventional silver nanoparticles (Ag NPs) are characterized with high loading rate and stacking phenomenon, leading to shedding caused biotoxicity and low catalytic efficiency. This seriously hinders their application in biomedicine. Here, we modified the highly dispersible Ag NPs and Ag single-atoms (SAs) synthesis by combining the halloysite clay nanotubes (HNTs) and dodecahydro-dodecaborate (closo-[B 12 H 12 ] 2- ) to increase the biocompatible properties and decrease the loading rate. This novel Ag single-atom nanoenzyme alongside Ag NPs nanoenzyme avoid the elevated-temperature calcination while maintaining the exceptionally high-level efficiency of Ag utilization via the reducibility and coordination stabilization of closo-[B 12 H 12 ] 2- and HNTs. With theoretical calculation and electron paramagnetic resonance, we confirmed that both Ag SAzymes and Ag NPs in HNT@B 12 H 12 @Ag nanoenzyme are capable decompose the H 2 O 2 into hydroxyl radical (·OH). For the application, we investigated the catalytic activity in the tumor cells and antitumor effects of HNT@B 12 H 12 @Ag nanoenzyme both in vitro and in vivo, and confirmed that it effectively suppressed melanoma growth through ·OH generation, with limited biotoxicity. This study provides a novel Ag nanoenzyme synthesis approach to increase the possibility of its clinical application., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Colloidal interactions between clay minerals and microplastics (MPs) in high salinity seawater are crucial for determining MP fate in marine environments. Montmorillonite (MMT) forms thin and pliable films that tightly cover MPs, while the thick and rigid lamellae of kaolinite (KLT) have limited contact with MPs, resulting in unstable bonding. However, a small quantity of small-sized KLT can create relatively stable heteroaggregates by embedding into the interstitial spaces of MPs. Both MMT and KLT colloids can decrease the mobility of MPs in seawater-saturated sea sand, but their breakthrough curves (BTCs) show distinct phenomena of "blocking" and "ripening", respectively. The "blocking" phenomenon occurs when flexible MMT adheres to the sand surface, depleting attachment sites quickly and inhibiting the retention of subsequent heteroaggregates of MMT-wrapped MPs. The transport of single MMT also experiences colloid competition for attachment sites, but pre-equilibration experiments reveal no competition between MMT and bare MPs for attachment sites. Instead, the attached MMT provides additional attachment sites for MPs. These results suggest that the wrapping of MPs by MMT plays a dominant role in the "blocking" of cotransport. In contrast, rigid KLT forms a three-dimensional stack on the sand surface, offering more attachment sites for subsequent MPs and heteroaggregates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)