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The electric double layer (EDL) has a pivotal role in screening charges on surfaces as in supercapacitor electrodes or colloidal and polymer solutions. Its structure is determined by correlations between the finite-sized ionic charge carriers of the underlying electrolyte, and, this way, these correlations affect the properties of the EDL and of applications utilizing EDLs. We study the structure of EDLs within classical density functional theory (DFT) in order to uncover whether a structural transition in the first layer of the EDL that is driven by changes in the surface potential depends on specific particle interactions or has a general footing. This transition has been found in full-atom simulations. Thus far, investigating the in-plane structure of the EDL for the primitive model (PM) using DFT has proved a challenge. We show here that the use of an appropriate functional predicts the in-plane structure of EDLs in excellent agreement with molecular dynamics simulations. This provides the playground to investigate how the structure factor within a layer parallel to a charged surface changes as a function of both the applied surface potential and its separation from the surface. We discuss pitfalls in properly defining an in-plane structure factor and fully map out the structure of the EDL within the PM for a wide range of electrostatic electrode potentials. However, we do not find any signature of a structural crossover and conclude that the previously reported effect is not fundamental but rather occurs due to the specific force field of ions used in the simulations. [ABSTRACT FROM AUTHOR]

Amino acids and their salts are amine compounds with great potential for the chemical absorption of CO2 via the amine method. The CO2 absorption properties of various amino acids and their salts have been previously reported. However, the detailed reaction mechanism of CO2 with basic amino acids in aqueous solutions has not yet been clarified. In this study, we focused on arginine (Arg), which has the highest basicity among the standard amino acids, and its monohydrochloride (ArgCl) and sodium (NaArg) salts for the dissolution of CO2 in the aqueous solutions of Arg, ArgCl, and NaArg. CO2 was chemically dissolved in aqueous Arg and NaArg solutions but not in the aqueous ArgCl solution. One‐dimensional 1H and 13C and two‐dimensional 1H‐13C heteronuclear multiple bond correlation nuclear magnetic resonance spectroscopy indicated that the final products in the aqueous Arg and NaArg solutions were protonated Arg and HCO3−. HCO3− was formed from both CO2‐bonded Arg/Arg− and CO32− intermediates in the aqueous NaArg solution but only from the CO2‐bonded Arg/Arg− intermediate in the aqueous Arg solution. In addition to their high environmental and biological compatibility, Arg and NaArg exhibit high CO2 absorption capacity, demonstrating their potential for practical use as naturally derived CO2 chemical absorbents. [ABSTRACT FROM AUTHOR]

Although concrete materials generally exhibit outstanding mechanical properties, it is susceptible against crack formation. It has been reported that narrow cracks (≤ 150 µm) could be naturally sealed in the cement matrix by externally supplied water-induced hydration. However, the crack width of larger than 150 µm is difficult to be sealed without using additional self-healing admixture. In this study, the self-healing cementitious mortar was successfully developed by using a combination of polyvinyl alcohol (PVA) fiber and superabsorbent polymer (SAP), aiming to heal the wide cracks. Although the mechanical properties were slightly reduced, it shows outstanding self-healing performance by using the dual admixtures. A self-healing rate of 60% was observed in the control sample with an initial crack width of 300 µm, while a self-healing rate of nearly 100% was confirmed with suitable SAP and PVA. In addition, it was confirmed that lower hydration degree of self-healing mortar in early stage contributes to the enhanced self-healing performance of developed composite system by internally supplied water from SAP. [ABSTRACT FROM AUTHOR]

Super absorbent polymer (SAP) has a capacity to enhance the characteristics of cementitious composites in both their fresh and hardened forms. However, it is essential to recognize that the strength of SAP concrete may decrease. By altering the concrete composition and selecting the appropriate type of SAP, it is possible to reduce this reduction. This work employs machine learning (ML) to tackle the issue of strength degradation. The analysis considers ten distinct variables linked to concrete composition and the type of SAP. The study uses machine learning approaches that involve both regression and classification tasks. The use of ensemble learning greatly improves the quality and accuracy of the results, showing its superiority in combining several models to produce more precise predictions. The findings demonstrate that the Support Vector Machines (SVM) and Extreme Gradient Boosting (XGBoost) regression algorithms accurately forecasted the percentage of reduction in strength in SAP concrete. These predictions were based on the concrete composition and SAP details, resulting in R2 values of 0.90 and 0.88, respectively. Furthermore, XGBoost exhibited the highest accuracy, reaching 0.94, when compared to the various categorization algorithms. According to the results, the mean squared error (MSE) of the ensemble model demonstrated superior outcomes. Furthermore, the SHapley Additive exPlanations (SHAP) reveal that some variables, including SAP%, SAP size, and compressive strength, have a significant influence on the strength reduction model. This study aims to bridge the gap between academic research and practical application by developing a web application that employs ensemble learning to precisely forecast the reduction in compressive strength caused by the usage of SAP. [ABSTRACT FROM AUTHOR]

The sustainability of global agriculture at higher productivity level is a concern owing to climate change, serious environmental footprints, dipping factor productivity and shrinking availability of natural resources, especially. The situation is worsening in the 'Food Bowl of India'—Indo‐Gangetic plains (IGP) by several amalgamated factors, such as declining groundwater, unpredictable precipitation owing to climate change and cultivation of heavy water duty crops. To neutralise these issues, a field experiment was executed for the period 2019–2021 to assess the efficacy of indigenous hydrogels (P‐hydrogel and Superabsorbent polymer hydrogel‐1118) and their application methods viz., seed treatment, slurry application and soil application on crop yield and water productivity, soil moisture dynamics and profitability in a soybean–wheat cropping system under irrigation and rainfed conditions. In both study years (2019–2020 and 2020–2021), due to higher seed germination percentage, irrigation application together with seed treatment and slurry application of superabsorbent polymer hydrogel‐1118 improved system productivity by 8.1%–26.7% and system water productivity by 17.6%–33.8% over control. Wheat grain yield was enhanced by 8.0% (2019–2020) to 32.2% (2020–2021) due to superabsorbent polymer hydrogel‐1118 hydrogel with 10 cm lesser use of irrigation water compared with control (no‐hydrogel). Soil moisture content in 0–15 cm soil layer was also found higher by 1.8%–2.4% in superabsorbent polymer hydrogel‐1118 and P‐hydrogel slurry‐applied plots. Therefore, higher gross profitability (31.8%), net profitability (89.8%) and B:C (26.9%) in wheat could be attributed to increased crop yields when seeds were treated with superabsorbent polymer hydrogel‐1118. Therefore, the utilisation of modified hydrogel application, in the form of seed treatment (seed coating) and slurry application has demonstrated improvement in seed germination, crop yield and water productivity and made soybean–wheat cultivation more economical. This approach presents a feasible solution to achieving a viable production system of soybean and wheat crops by reducing irrigation amounts in the IGP of India, as well as other comparable ecological places worldwide. [ABSTRACT FROM AUTHOR]

Concrete pavements require substantial amount of water for curing process which is a challenge considering its large surface area and to mitigate this challenge, use of internal curing agents is considered in this study. The use of super-absorbent polymer (SAP) has been reported in this regard the increased porosity resulting after release of internal water is a major concern here. Alternatively, polymers such as polyvinyl alcohol (PVA) and polyethylene glycol (PEG) can be considered for self-curing. Scarce literature is available with respect to these two polymers. In this study, the workability, strength, durability, and microstructure properties of pavement-quality concrete with PVA and PEG were analyzed and compared with that of SAP and conventionally cured concrete. The results indicated that at the optimal dosage, PVA/PEG exhibited better mechanical and durability properties when compared to conventionally cured concrete; SAP exhibited a reduction in strength for dosages higher than 0.6%, due to the increased porosity and this was verified through SEM images also. The measurement of internal humidity on concrete slabs showed that internal humidity retention was better in the case of PEG. Pavement design as per IRC:58-2015 design guideline and cost analysis for the respective thickness showed that the use of certain self-curing additives results in economic advantages also. [ABSTRACT FROM AUTHOR]

Cellulose consists of a natural, rigid polymer that is widely used to improve the mechanical and water‐holding properties of hydrogels. However, its abundant hydroxyl groups make it highly absorbent to free water, leading to swelling behavior. This increased free water content will also decrease mechanical and adhesive performance. In this study, cellulose is successfully hydrophobically modified to reduce its absorption of free water. Gelatin is then cross‐linked with cellulose through a Schiff‐base reaction, resulting in increased bound water content. This significantly enhances resistance to swelling and permeability, and improves the freeze–thaw stability of the hydrogel. Due to its internal hydrophobicity, water molecules can quickly penetrate into the interior, reducing their residence time on the hydrogel surface. This allows the hydrogel to maintain high adhesion in natural environments, achieving an adhesion strength of up to 3.0 MPa on wood and bamboo‐based materials. The hydrogel can retain its adhesive properties even after prolonged exposure to a humid environment. Additionally, Na+ ions enhance the electrical conductivity and sensitivity of the hydrogel (gauge factor (GF) = 1.51), demonstrating its potential applications in flexible sensing. [ABSTRACT FROM AUTHOR]

This study explores the synthesis and characterization of superabsorbent hydrogels derived from chemically modified gum Arabic, designed for controlled folic acid release. The synthesis involves a two‐step process: carboxymethylation followed by grafting with 2‐hydroxyethyl methacrylate via gamma irradiation. The resulting hydrogels exhibit enhanced mechanical strength and controlled diffusivity, essential for nutrient delivery systems. Key factors such as copolymer composition and irradiation dose are investigated, affecting the synthesis process. Systematic studies of swelling behaviors reveal that the hydrogel achieves a maximum swelling of 888.1% at 40 °C. The hydrogels are loaded with folic acid, and in vitro, sustained release profiles are examined under various pH conditions. The maximum release of 83.3% is observed after 24 h at pH 7.0, following a Korsmeyer–Peppas release mechanism. Different characterization techniques, confirm the successful synthesis and unique properties of the superabsorbent hydrogels. Rheological behavior analysis, scanning electron microscopy, and biocompatibility assessments provide a comprehensive understanding of the hydrogel structures. Gamma irradiation ensures a homogeneous network structure, crucial for optimal swelling behavior and mechanical properties. This research highlights the potential of eco‐friendly biopolymer hydrogels in precise drug delivery applications, leveraging the safety and process control benefits of gamma irradiation. [ABSTRACT FROM AUTHOR]

This study aimed to experimentally investigate the compressive strength and air voids of cement pastes with varying dosages of Superabsorbent Polymer (SAP) and water-to-cement (w/c) ratios. Cement pastes were prepared using three different w/c ratios of 0.4, 0.5, and 0.6, along with different dosages of SAP ranging from 0.2% to 0.5% by weight of cement. Additionally, SAP was introduced in two forms: dry and wet. After casting the cubes, two distinct curing conditions were employed: curing at a temperature of 20 °C with a Relative Humidity (RH) of 60% (Curing 1), and water curing (Curing 2). The results revealed that the addition of SAP increased early strength when subjected to Curing 1, followed by a decrease in later strength. On the other hand, samples with SAP and water curing exhibited higher strength compared to those without SAP, especially with w/c ratios of 0.4 and 0.5. However, at a w/c ratio of 0.6, nearly all samples showed a reduction in strength compared to those without SAP. Furthermore, air void analysis was performed on all samples cured for 28 days using an image analysis technique. The samples containing wet SAP resulted in a higher total air content compared to the samples with dry SAP. Additionally, the incorporation of wet SAP in cement paste led to lower specific surface areas and a higher spacing factor than the samples with dry SAP. These findings suggest that the clumping of wet SAP particles during presoaking resulted in coarser air voids compared to the samples containing dry SAP. [ABSTRACT FROM AUTHOR]

Water scarcity, a challenge expected to worsen with climate change, significantly hinders native plant community restoration. Enhancing seed‐based restoration requires methods to increase the water availability for seeds and seedlings. Surfactants and superabsorbent polymers (SAPs) can improve soil water‐holding capacity and infiltration, but their use in seed enhancements remains underexplored. We investigated whether pellets containing surfactants or SAPs could improve seedling emergence of two native species (Rytidosperma caespitosum and Chrysocephalum apiculatum) common in temperate grasslands in south‐eastern Australia under different watering treatments. We used a randomized block design with five watering treatments to simulate predicted changes in precipitation for south‐eastern Australia: ambient, two reducing overall water volume, and two reducing watering frequency while increasing watering volume to maintain ambient treatment water volume. We explored four enhanced pellets (two containing surfactants and two containing SAPs) and non‐pelleted seeds. Our results showed that watering events with larger volumes but reduced frequency increased seedling emergence. Under these conditions, block co‐polymer surfactants further increased seedling emergence of C. apiculatum, while synthetic SAP pellets promoted emergence of R. caespitosum. Block co‐polymer surfactants decreased R. caespitosum emergence, and both SAPs reduced C. apiculatum emergence under reduced watering frequency. A 50% reduction in overall water volume significantly reduced seedling emergence for both species, regardless of seed enhancement. These findings suggest that surfactants and SAP pellets can improve the success of seed‐based restoration under ambient conditions and when rainfall events are larger in volume but reduced in frequency, but not when the overall volume of rainfall is reduced. [ABSTRACT FROM AUTHOR]

Translation abstract Air entraining concrete with superabsorbent polymers (SAP) – Part 3: robustness to fluctuations in raw materials and ambient conditionsThe production of the required artificially introduced air void content in fresh concrete poses a major challenge under certain practical construction conditions. Fluctuating properties in the air void content can lead to increased rejection of deliveries as well as to poor concrete properties. The influences on air void formation and stability are manifold and result from concrete technology, production‐related and environmental conditions. The robustness of superabsorbent polymers (SAP) against practical variations for the introduction of an artificial air void system into hardened concrete is still relatively unknown. Building on the previous parts 1 (fresh concrete properties) and 2 (hardened concrete properties), this article describes and discusses systematic investigations into the robustness of LP concretes with both superabsorbent polymers and classic LP formers to fluctuations in the starting materials or ambient conditions (temperature). The experimental results show that superabsorbent polymers (SAP) in concrete react very robustly to such practical construction influences with regard to the introduction of artificial air voids and the resulting frost resistance. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces have been widely studied for their self-cleaning properties. However, most of the constructed superhydrophobic surfaces had problems of changing the surface morphology and color of paper/cloth. An extremely dilute superhydrophobic solution was prepared by hybrid assembly of aminated nano-SiO2 and high fluorine epoxy polymer P(FOEMA-r-GMA). The preparation of superhydrophobic cotton (SHC) and superhydrophobic book paper (SHBP) was studied through the optimal construction conditions of solution impregnation method. The optimal construction conditions for SHC were as follows: The concentration of fluorinated epoxy polymer was 3 mg/mL, the soaking time was 5 h, the drying time was 8 h, and the drying temperature was 120 °C. The maximum WCA was 158° ± 3°, and the minimum WRA was 4° ± 3°. SHC surface had good hydrophobic effect, acid and alkali resistance, and self-cleaning effect. Additionally, its surface morphology still remained basically unchanged. SHC could be used for oil–water separation with a maximum oil–water separation rate of 98.4%. The optimal construction conditions for SHBP were: The concentration of fluorinated epoxy polymer was 3 mg/mL, the soaking time was 9 h, the drying time was 6 h, the maximum WCA was 155° ± 3°, and the minimum WRA was 6° ± 1°. The hydrophobicity of SHBP was greatly improved; it would extract selective adsorbing oil from the oil–water mixture and slightly reduce its smoothness. [ABSTRACT FROM AUTHOR]

The novel zinc-incorporated superabsorbent hydrogel (ZSAH) was fabricated by interpenetrating zinc micronutrient in xanthan gum and carboxymethyl tamarind kernel gum with sodium methacrylate. Various compositions of SAH hydrogels were fabricated by varying the concentrations of biopolymers, monomer, cross-linker, and initiator. Zinc chloride was incorporated in the best-swelled hydrogel for the release of Zinc as a micronutrient. Synthesized SAH and ZSAH were characterized by FTIR, SEM, and TGA techniques. The influence of various solvents, such as standard saline solution, different pH solutions (4, 9, and 12), and distilled water on the swelling degree of ZSAH. Moreover, ZSAH was utilized for controlled-release studies of zinc micronutrient in both soil and water. Moreover, the kinetic modeling of zinc release was done using Korsmeyer–Peppas and Higuchi models. It was found that the Korsmeyer–Peppas model with a higher value of regression coefficient (R2) close to unity fitted well in the zinc release pattern in soil and water. Moreover, the estimated value of diffusion exponent (n) indicated that the mechanism of zinc release followed Fickian diffusion. The ZSAH was used for the study of sesame plant growth. It was found that the number of germination of seeds count for ZSAH was significantly greater than that for the controlled soil. [ABSTRACT FROM AUTHOR]

Self-desiccation-induced shrinkage may result in cracking at an early age, which is averse to the durability of concrete. Internal curing (IC) agents, such as superabsorbent polymers (SAP), are normally used for moisture regulation and shrinkage reduction. In addition, the make-up of recycled shale lightweight aggregate (RSLA) results in a good absorbing capacity, which makes it a potential candidate for IC. In this paper, the synergistic effect of SAP and RSLA on the relative humidity (RH) variation in early-age concrete under sealed conditions is investigated experimentally in terms of the setting time, relative humidity, and autogenous shrinkage. The results indicate that adding SAP and presoaked RSLA can significantly postpone the initial and final setting times. The initial setting time of RSLA30 and SAP06 is delayed by 127 and 171 min, respectively, compared to the benchmark mixture. In addition, increasing the amounts of SAP and presoaked RSLA can effectively extend the duration of the vapour-saturated stage, reducing the decrease in RH and autogenous shrinkage at 28 days. When the RSLA dosage increases from 0 to 10%, 20%, and 30%, the duration of the vapour-saturated stage is extended by 2, 9.4, and 26 days, respectively. Moreover, due to different water desorption behaviours, more IC water released by RSLA during the initial stage can slow the water release of SAP and lead to a higher RH level at 28 days. [ABSTRACT FROM AUTHOR]

Superabsorbent polymer gels are widely used in commercial areas, such as in hygiene products. A key aspect in these and other applications is the gel swelling kinetics, and a key factor of influence on that is the hydrophobicity of the gel. This paper reports on the synthesis of superabsorbent polymer microgel particles with four differently hydrophobic crosslinkers: N,N’‐methylenebisacrylamide (MBAA), N,N’‐ethylenebisacrylamide (EBAA), N,N’‐propylenebisacrylamide (PBAA), and N,N’‐butylenebisacrylamide (BBAA). This work uses droplet‐based microfluidics to produce uniform and well‐defined microgel specimen and study the influence of the crosslinker hydrophobicity on the swelling kinetics. In particular, this work determines swelling constants and their dependencies on the temperature of the swelling medium as well as the activation energies of swelling in relation to the crosslinker hydrophobicity. This work finds two competing effects, leading to a narrow window in which the activation energy of the swelling of the microgels decreases with increasing crosslinker hydrophobicity. [ABSTRACT FROM AUTHOR]

The adsorption mechanism of superabsorbent polymer (SAP) can provide theoretical guidance for their practical applications in different environments. However, there has been limited research on the mechanism of attapulgite–sodium polyacrylate. This research aimed to compare the Cd(II) adsorption characteristics and water retention properties of organic–inorganic composite SAP (attapulgite–sodium polyacrylate, OSAP) and organic SAP (polyacrylamide, JSAP). Batch experiments were used to investigate the kinetics of Cd(II) adsorption, as well as the thermodynamic properties and factors influencing these properties. The results show that the Cd(II) adsorption capacity was directly proportional to the pH value. The maximum adsorption capacities of OSAP and JSAP were of 770 and 345 mg·g−1. The Cd(II) adsorption for OSAP and JSAP conformed to the Langmuir and the quasi-second-order kinetic model. This indicates that chemical adsorption is the primary mechanism. The adsorption process was endothermic (ΔH0 > 0) and spontaneous (ΔG0 < 0). The water adsorption ratios of OSAP and SAP were 474.8 and 152.6 in pure water. The ratio decreases with the increase in Cd(II) concentration. OSAP and JSAP retained 67.23% and 38.37% of the initial water adsorption after six iterations of water adsorption. Hence, OSAP is more suitable than JSAP for agricultural and environmental ecological restoration in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

The development of new materials for antifreezing and anti‐icing applications is a big challenge in industry and academic area. Inspired by the antifreeze proteins, latex particles with superhydrophilic zwitterionic shells and superhydrophobic cores are synthesized by reversible addition‐fragmentation chain transfer emulsion polymerization, and the applications of the latex particles in antifreezing and anti‐icing applications are investigated. In antifreezing study, the critical aggregate temperature (CAT) of the latex particles decreases, and the separation of the melting and freezing temperature of ice increases with the particle concentration. Enzyme molecules can be cryopreserved in the particle solution, and their bioactivities are well maintained. Latex particles are casted into latex films with dynamic surfaces. Anti‐icing performances, including antifrosting properties, freezing delay time, and ice adhesion strengths, are studied; and the water‐treated latex films present stronger anti‐icing properties than other films, due to the synergistic effects of the superhydrophilic and superhydrophobic components. In addition, latex particles with zwitterionic shells and poly(n‐butyl methacrylate) cores, and latex particles with small molecular surfactant on the surfaces are synthesized. The antifreezing performances of the latex particles and anti‐icing properties of the latex films are compared. [ABSTRACT FROM AUTHOR]

This study evaluated the self‐healing characteristics of superabsorbent polymers (SAP) in epoxy polyamide paint systems applied using brush application. The SAP underwent preliminary characterization to determine its primary properties and was then incorporated into the epoxy primer at different percentages. The epoxy‐SAP coating systems then underwent various tests to evaluate their self‐healing capability. Excellent adhesion is obtained with the coating system composed of initial epoxy primer, epoxy‐SAP layer, final epoxy primer, and an epoxy enamel topcoat. Electrochemical impedance spectroscopy (EIS) reveals that the addition of SAP increased the charge transfer resistance and pore resistance and decreased the double layer capacitance of the coating system in a span of 5 h, confirming the self‐healing of the coating. Maximum corrosion protection for 5 h is obtained between 15 to 20 wt% SAP. Lastly, it is determined through long‐term immersion tests that the addition of SAP in the coating significantly decreases the rust formation; however, the coating starts to peel off due to the swelling of SAP after 2–3 days. [ABSTRACT FROM AUTHOR]

The development of new methods to improve the water absorption performance of polymeric materials, taking into account their environmental friendliness, is a promising research direction in Itaconic acid based water‐absorbent polymeric materials. In this study, from the perspective of environmental protection, we propose to design highly absorbent hydrogels with a novel villous‐like structure by using hydrophilic itaconic acid as the raw material and combining it with a novel villous‐like network structure to substantially increase the contact area between the hydrogel and water, thus improving the water absorption rate of the hydrogel. Itaconic acid is water‐soluble and renewable. The widespread use of polymeric water‐absorbent polymers from traditional petroleum sources poses a serious threat to the sustainability of ecosystems, and therefore, itaconic acid has attracted much attention as an alternative to petroleum‐based polymers. The villous‐like network structure is inspired by the villi of the small intestine, the special presence of which expands the absorptive surface area of the small intestine by a factor of about 600, and it is therefore hypothesized that the introduction of this special structure could help the hydrogel to greatly increase the contact area with water and thus achieve the high water absorption properties of the hydrogel. This is also the first time that the villus‐like network structure has been applied to Itaconic acid based hydrogels. The results show that the hydrogel has the property of rapid water absorption and swelling and the water absorption rate of the hydrogel can reach up to 2210 g/g, and the villous‐like structure formed by the hydrogel can be observed in the SEM image. The water‐absorption test of the hydrogel showed that when the molar mass ratio of itaconic acid to acrylic acid was 1:4, the hydrogel absorbed water and swelled rapidly in a short time. The results of the water retention test showed that the hydrogel still existed after 5 days, and the water retention was greater than 86%. In addition, the hydrogel had high reusability, and the water absorption performance of the hydrogel could still reach 89.12% after 6 cycles of the water absorption test. Hydrogel with high water‐absorbing property has good application prospects as fast swelling material in the field of flood control of water conservancy projects. [ABSTRACT FROM AUTHOR]

The swelling behaviors and water retention of superabsorbent sand-fixing materials prepared from acrylic acid/acrylamide copolymer (AA/AM) and acid-modified attapulgite under ultrasonic treatments and different pH conditions were investigated. The results demonstrated that a suitable amount of attapulgite can effectively improve the absorption capacity and saltwater performance. The superabsorbent achieved the highest absorptions of 1257.54 g/g and 209.45 g/g in distilled water and a 0.9 wt% NaCl solution, and a higher water absorbency occurred over a wide pH range of 5~9 when the ultrasonic power was 200 W and the attapulgite content was 10%. The addition of attapulgite could significantly increase the water absorption and retention. [ABSTRACT FROM AUTHOR]

The water-retaining and yield-increasing capacity of super-absorbent polymer (SAP) are essential for soil remediation in arid and semi-arid areas. Water availability is an increasing challenge to plant development and crop yield. During the growing seasons in 2021 and 2022, the present study was conducted to evaluate the effect of the addition of different amounts of SAP on the development and yield of green beans (Phaseolus vulgaris L. cv Bronco) under varying water deficit stresses, compared with the control treatment without SAP and water deficit stress. The results demonstrated that a 50% reduction in water requirement (WR) resulted in significant decreases in leaf fresh weight, specific leaf area, leaf total chlorophyll content, pod number, leaf free water content, pod fresh weight per plant, and yield. Decreases were also found in pod total chlorophyll content, carotenoids, dry matter and total protein, leaf proline content, and crude fiber content. Additionally, leaf water saturation deficit was significantly increased under the stress compared with the full irrigation at 100% WR. However, irrigation at 75% WR increased pod contents of ascorbic acid, total sugars, and leaf bound water. The current study also indicated that addition of SAP significantly enhanced the above-mentioned growth characteristics under irrigation at 50% and 75% WR. Treatment with SAP at 3 g/plant was the most effective in mitigating the adverse effects of water deficiency, especially at the irrigation rate of 75% WR. Pearson's correlation analysis showed significantly positive correlations between the growth parameters, as well as pod yield, under water stress and SAP. This study provides a promising strategy for green bean cultivation by adding SAP to soil to alleviate water shortage stress. [ABSTRACT FROM AUTHOR]

Superabsorbent polymers (SAPs) are a class of cross-coupled hydrophilic networks that have an extraordinary capacity to absorb and retain water. It is primarily because of the additional ionic cross-linking of SAPs, their porous wavy structure, a large number of hydrophilic functionalities, the high elasticity of the chains, and the enlarged free volumes between the polymeric chains, that all contribute to the enhancement of the swelling capability of superabsorbent hydrogels. These exceptional attributes have endowed them to be an alternative to conventional hydrogels in various applications. In view of the importance of this class of absorbent material and their diverse appliances, this review deliberates the experimental methods for characterizing superabsorbent polymers, including the officially accepted industrial measurements of their unique attributes, namely, swelling among others. In addition, the review highlights recent advances in the field of superabsorbent polymers encompassing nanofiltration, heat resistance, and absorbency, drug delivery, disposable hygiene products, nanomedicines, and the removal of heavy metals from wastewater and agriculture domains. [ABSTRACT FROM AUTHOR]

The abundant natural volcanic ash (NVA) in East Africa is a prospective supplementary cementitious material that may be used to produce green and economical railway concrete. To mitigate the shrinkage of concrete with NVA, internal curing using a superabsorbent polymer (SAP) is employed in this study. The compressive strength, autogenous shrinkage, and drying shrinkage of internally cured concrete with NVA were measured. In addition, the water loss and internal relative humidity of internally cured concrete with NVA were analyzed. The results indicate that the compressive strength of concrete with NVA shows a linear decreasing trend with SAP. In addition, SAP significantly reduces the autogenous shrinkage but slightly increases the drying shrinkage of concrete with NVA. The internal curing using SAP increases the water loss of concrete, whereas the water released from SAP still significantly improves the internal relative humidity (IRH) of concrete. The positive influence of internal curing on the autogenous shrinkage overwhelms the unexpected influence on the drying shrinkage, resulting in the mitigated shrinkage of concrete with NVA. [ABSTRACT FROM AUTHOR]

The frontal polymerization (FP) of carbon/epoxy (C/Ep) composites is investigated, considering FP as a viable route for the additive manufacturing (AM) of thermoset composites. Neat epoxy (Ep) resin-, short carbon fiber (SCF)-, and continuous carbon fiber (CCF)-reinforced composites are considered in this study. The evolution of the exothermic reaction temperature, polymerization frontal velocity, degree of cure, microstructures, effects of fiber concentration, fracture surface, and thermal and mechanical properties are investigated. The results show that exothermic reaction temperatures range between 110 °C and 153 °C, while the initial excitation temperatures range from 150 °C to 270 °C. It is observed that a higher fiber content increases cure time and decreases average frontal velocity, particularly in low SCF concentrations. This occurs because resin content, which predominantly drives the exothermic reaction, decreases with increased fiber content. The FP velocities of neat Ep resin- and SCF-reinforced composites are seen to be 0.58 and 0.50 mm/s, respectively. The maximum FP velocity (0.64 mm/s) is observed in CCF/Ep composites. The degree of cure (αc) is observed to be in the range of 70% to 85% in FP-processed composites. Such a range of αc is significantly low in comparison to traditional composites processed through a long cure cycle. The glass transition temperature (Tg) of neat epoxy resin is seen to be approximately 154 °C, and it reduces slightly to a lower value (149 °C) for SCF-reinforced composites. The microstructures show significantly high void contents (12%) and large internal cracks. These internal cracks are initiated due to high thermal residual stress developed during curing for non-uniform temperature distribution. The tensile properties of FP-cured samples are seen to be inferior in comparison to autoclave-processed neat epoxy. This occurs mostly due to the presence of large void contents, internal cracks, and a poor degree of cure. Finally, a highly efficient and controlled FP method is desirable to achieve a defect-free microstructure with improved mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

Superabsorbent polymers (SAPs) are a key constituent in baby diapers and adult incontinence products. To develop new SAPs, lab tests are used to measure properties that are considered important for these products. However, these manual tests are often time-consuming and tedious. This paper introduces an automatic method to measure absorption under pressure (aAUP) using industry robots. The new robotic method addresses limitations in an industry standard absorption under pressure (AUP) method. The new aAUP method can run continuously, generating more and better data to aid in product development. It enables to put the Buchholz theory on SAPs for predicting their properties to practice by reduction of manual effort and by producing excellent data quality. This has been shown on commercial polymers from different production processes, with varied particle size distributions and shapes. The aAUP data has also been shown to accurately predict other properties of SAPs relevant for their application in hygiene articles, making it a useful tool for understanding the underlying science and facilitating product development. [ABSTRACT FROM AUTHOR]

Cement-based materials are fundamental in the construction industry, and enhancing their properties is an ongoing challenge. The use of superabsorbent polymers (SAP) has gained significant attention as a possible way to improve the performance of cement-based materials due to their unique water-absorption and retention properties. This study investigates the multifaceted impact of kaolin intercalation-modified superabsorbent polymers (K-SAP) on the properties of cement mortar. The results show that K-SAP significantly affects the cement mortar’s rheological behavior, with distinct phases of water absorption and release, leading to changes in workability over time. Furthermore, K-SAP alters the hydration kinetics, delaying the exothermic peak of hydration and subsequently modifying the heat release kinetics. Notably, K-SAP effectively maintains a higher internal relative humidity within the mortar, reducing the autogenous shrinkage behavior. Moreover, K-SAP can have a beneficial effect on pore structure and this can be ascribed to the internal curing effect of released water from K-SAP. [ABSTRACT FROM AUTHOR]

Stacking compacted filtered tailings has become an option to cope with the new Brazilian regulations while providing a safe disposal method for the tailings. It has become feasible due to recent developments in dewatering technologies. Still, the dewatering processes may need to be improved to attain acceptable moisture contents considering the on-field compactable range. Also, the filtered material's moisture content is highly influenced by the weather conditions, especially during the rainy season in the southeast of Brazil. Additives are a possible solution to accelerate moisture reduction. However, scientific studies in the technical literature still need to attest to the effectiveness of these methods to tailings, mainly on a full scale. Accordingly, the present research evaluates the performance of two additives to hasten filtered iron ore tailings drying for dry stacking purposes: commercially available quicklime and superabsorbent polymer. Also, undrained triaxial tests were conducted on specimens retrieved from on-field compacted layers to investigate the additive's influence on the tailings' mechanical behaviour. Initial confining pressures ranging from 100 to 600 kPa were used. The results have shown the inefficacy of the superabsorbent additives in boosting the drying process for on-field conditions and the efficiency of the quicklime in doing so. Furthermore, no substantial changes in the mechanical response were observed due to the insertion of quicklime. This highlights the novelty of the present study in the context of iron ore tailings management. [ABSTRACT FROM AUTHOR]

There is less research on the mechanical behavior of cement-based materials containing superabsorbent polymers (SAP) under high strain rate. In this paper, the total porosity and macroscopic pore (> 100 µm) porosity of cement-based materials containing SAP were investigated by the use of mercury intrusion and graphical techniques. The effects of SAP particle size and extra water on the quasi-static (10-5 s-1) and dynamic (60 ~ 110 s-1) mechanical properties of the modified materials were analysed. Based on the study of the crack propagation behavior, the damage behavior of the cement-based materials was analyzed under high strain rates. The results show that the addition of extra water and the increase of SAP particle size improve the total porosity and macroscopic pore porosity of the materials, which reduce the compressive strength and elastic modulus of the specimens under quasi-static and dynamic compression. The addition of extra water and the increase of SAP particle size also enlarge the compressive strength dynamic increase factor and elastic modulus dynamic increase factor of the cement-based materials, which is due to the fact that an increase in total porosity and macroscopic pore porosity induces a change in the crack extension path, an increase in fragmentation, and a delay in the strain response. [ABSTRACT FROM AUTHOR]

Cracking and repair of concrete have always been the focus of attention in engineering field. Superabsorbent polymers (SAP) have a certain crack self-healing function. In this paper, the liquid absorption properties of SAP under different environmental solutions (NaOH, NaCl and distilled water) were tested. The compressive strength recovery rate of cracked specimens, the self-healing rate of different crack widths (0.1, 0.2 mm) and the crack filling state were used as repair indicators. The repair effect of SAP with different mass fractions (0%, 0.5%, 1.0%) on cracked mortar specimens under different environmental solutions was analyzed. The results show that the liquid absorption rate of SAP in different environmental solutions increases rapidly and then tends to be stable, and the liquid absorption rate of SAP in NaOH environmental solution is the highest. The incorporation of SAP improves the compressive strength recovery rate of cracked mortar specimens under different environmental solutions to a certain extent. Among them, the compressive strength recovery rate of specimens mixed with 0.5% SAP in NaOH environmental solution for 28 d is the highest, which is 17% higher than that of reference group. The incorporation of SAP improves the self-healing properties of mortar specimens with different crack widths in different environmental solutions. With the increase of SAP content, the self-healing properties of mortar specimens with 0.2 mm crack width repaired in NaOH environmental solution for 28 d is significantly higher than that of distilled water and NaCl solution. The self-healing rate of specimens with 1.0% SAP in NaOH environmental is 90%. The incorporation of SAP cooperates with hydration products to seal the crack mouth, so it is beneficial to solution improve the durability of cement mortar. [ABSTRACT FROM AUTHOR]

Water scarcity, exacerbated by climate change and international conflicts, poses significant challenges to maize production. Research has shown that interventions like plant charcoal, superabsorbent polymers, and anti-transpiration agents can mitigate water stress effects, enhancing maize growth indicators. Therefore, the experiment was conducted in the fields of the Department of Field Crops, College of Agricultural Engineering Sciences, University of Baghdad, in the spring season of 2022. The aim of the experiment was to increase the growth indicators of maize leaves exposed to water reduction levels using polymer, charcoal, and antiperspirant. The experiment was designed as a randomized complete block design (RCBD) in a split-plot arrangement with three replicates. The main plots were occupied by water reduction levels (0, 25 and 50%), while the subplots were occupied by the additives: sodium acrylate, biochar, antiperspirant, charcoal + antiperspirant, acrylate + antiperspirant, acrylate + charcoal + antiperspirant, and control. The charcoal treatment was able to join the binary and ternary treatments to give a significant increase over the other treatments in the number of leaves. In the weight of leaves, the acrylate + antiperspirant treatment was behind them, and they remained significantly superior. There was no significant difference observed among treatments in leaf area. However, the antiperspirant treatment exhibited the lowest percentage of leaf water loss, significantly differing from all other treatments. Additionally, the antiperspirant treatment consistently demonstrated the highest relative water content across all treatments in which it was applied, a trend similar to charcoal treatments. As for the interaction between the two factors of the study, it appeared that there was no significant difference in the charcoal + antiperspirant treatment at the levels of 0 and 25%, but the decrease became significant at the level of 50%. [ABSTRACT FROM AUTHOR]

In light of the current water scarcity, one strategy for reducing water consumption in irrigated agriculture is to reduce the amount of irrigation water compared to full crop irrigation or in other words deficit irrigation. Deficit irrigation management may be a critical issue due to climate change. Incorporation of different soil conditioners can improve soil hydro-physical properties and mitigate negative effects in water-stressed conditions. Recent review articles either addressed specific crop behavior under water deficit or covered a single type of soil conditioners. This manuscript represents an inclusive review providing insight into deficit irrigation methods incorporated with different soil conditioners. Crop response to deficit irrigation is discussed in the light of some mathematical models. Three main types of soil conditioners are covered: bentonite, biochar, and super-absorbent polymers. Mechanisms associated with effects of each conditioner to enhance soil water retention is highlighted as well. Previous study findings were discussed comparatively and future prospective, recommendations and challenges were addressed. [ABSTRACT FROM AUTHOR]

Gel treatment is an economical and efficient method of controlling excessive water production. The gelation of in situ gels is prone to being affected by the dilution of formation water, chromatographic during the transportation process, and thus controlling the gelation time and penetration depth is a challenging task. Therefore, a novel gel system termed preformed particle gels (PPGs) has been developed to overcome the drawbacks of in situ gels. PPGs are superabsorbent polymer gels which can swell but not dissolve in brines. Typically, PPGs are a granular gels formed based on the crosslinking of polyacrylamide, characterized by controllable particle size and strength. This work summarizes the application scenarios of PPGs and elucidates their plugging mechanisms. Additionally, several newly developed PPG systems such as high-temperature-resistant PPGs, re-crosslinkable PPGs, and delayed-swelling PPGs are also covered. This research indicates that PPGs can selectively block the formation of fractures or high-permeability channels. The performance of the novel modified PPGs was superior to in situ gels in harsh environments. Lastly, we outlined recommended improvements for the novel PPGs and suggested future research directions. [ABSTRACT FROM AUTHOR]

Abstract Super absorbent polymer (SAP) has a capacity to enhance the characteristics of cementitious composites in both their fresh and hardened forms. However, it is essential to recognize that the strength of SAP concrete may decrease. By altering the concrete composition and selecting the appropriate type of SAP, it is possible to reduce this reduction. This work employs machine learning (ML) to tackle the issue of strength degradation. The analysis considers ten distinct variables linked to concrete composition and the type of SAP. The study uses machine learning approaches that involve both regression and classification tasks. The use of ensemble learning greatly improves the quality and accuracy of the results, showing its superiority in combining several models to produce more precise predictions. The findings demonstrate that the Support Vector Machines (SVM) and Extreme Gradient Boosting (XGBoost) regression algorithms accurately forecasted the percentage of reduction in strength in SAP concrete. These predictions were based on the concrete composition and SAP details, resulting in R2 values of 0.90 and 0.88, respectively. Furthermore, XGBoost exhibited the highest accuracy, reaching 0.94, when compared to the various categorization algorithms. According to the results, the mean squared error (MSE) of the ensemble model demonstrated superior outcomes. Furthermore, the SHapley Additive exPlanations (SHAP) reveal that some variables, including SAP%, SAP size, and compressive strength, have a significant influence on the strength reduction model. This study aims to bridge the gap between academic research and practical application by developing a web application that employs ensemble learning to precisely forecast the reduction in compressive strength caused by the usage of SAP.

Cobalt and nickel are vital metals for the transition to a decarbonized society, currently in critical supply conditions to meet future demands. The recovery of those metals from secondary sources can mitigate this issue, as well as treating hazardous waste and increasing its economic value. In this work, ionic polymers inspired by deep eutectic solvents (DES) were studied for cobalt and nickel recovery from representative recycling solutions. These polymers were prepared by simple and fast photopolymerization process combining [2-(methacryloyloxy) ethyl] trimethylammonium chloride (METAC) with a series of hydroxylated compounds (e.g. alcohol and phenolic compounds). Different driving forces for metal absorption; ionic interactions, hydrogen bonding coordination, acidity of the media and polymer swelling have been investigated. The poly(METAC:1-butanol) polymer showed the highest absorption capacity (46 ± 5 mg g−1 and 46 ± 4 mg g−1 for cobalt and nickel, respectively), competing with conventional materials. Moreover, the metal stripping and recovery step was investigated. Favourably, deionized water presented the highest desorption efficiency, in comparison with HCl, rendering this process 'greener' and highly cost-effective. Finally, the ionic polymers were successfully reused as absorbents for five absorption/desorption cycles, maintaining structural integrity. This approach can pose an alternative way of using systems inspired by DES, with application at a larger scale upon further optimizations. [ABSTRACT FROM AUTHOR]

Using synthetic polymers in the production of superabsorbent polymers offers significant advantages such as low cost, extended service life, and a high water absorption rate. However, concerns about the environmental impact and potential adverse effects on plant growth arise from the degradation products of these polymers after disposal. In addition, handling these polymers can cause rashes, irritations, and even toxic shock syndrome. To overcome these issues, researchers are exploring the synthesis of superabsorbent polymers from natural sources. Cottonseed protein is identified as a potential natural polymer for the synthesis of natural superabsorbent polymers. Notably, there is no existing research on hydrogel synthesis using cottonseed protein and 2-acrylamido-2-methylpropanesulfonic acid (AMPS). This study addresses this gap by focusing on modifying cottonseed protein (CSP) through graft copolymerization, utilizing the partially neutralized form of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) in a water-based solution. N,N-methylene bisacrylamide serves as the crosslinking agent, while potassium persulfate (PPS) and sodium bisulfite (SBS) function as redox initiators. The optimization of hydrogel synthesis conditions was achieved using Design Expert-11 software, adjusting the AMPS to CSP ratio. The research reveals that the hydrogel reaches its maximum swelling capacity (195.7 g/g) with 0.03 g of MBA, 0.01 g of PPS, 0.01 g of SBS, and a 1wt% AMPS to CSP ratio. Swelling properties were assessed under diverse pH conditions, and the study delved into swelling kinetics (both pseudo-first-order model and pseudo-second-order model) and performance under different loads. Grafting evidence was validated through FTIR analysis. The maximum water uptake was obtained when there was no load, and the pH value was around neutral (7). In conclusion, the results indicate that the developed hydrogel holds a promise for applications in water retention, reducing water loss, and serving as an environment-friendly, biocompatible superabsorbent polymer so we can use such hydrogel in biomedical applications. [ABSTRACT FROM AUTHOR]

Fast-growing poplar plantations are considered a great benefit to timber production, but water availability is a key factor limiting their growth and development, especially in arid and semi-arid ecosystems. Super-absorbent polymers facilitate more water retention in soil after rain or irrigation, and they are able to release water gradually during plant growth. This study aimed to examine the effects of reduced irrigation (60% and 30% of conventional border irrigation) co-applied with super-absorbent polymers (0, 40 kg/ha) on root exudates, enzyme activities, microbial functional diversity in rhizosphere soil, and volume increments in poplar (Populus euramericana cv. 'Neva'). The results showed that 60% border irrigation co-applied with super-absorbent polymers significantly increased the content of organic acids, amino acids and total sugars in the root exudates, and the activities of invertase, urease, dehydrogenase, and catalase in the rhizosphere soil in comparison to conventional border irrigation without super-absorbent polymers. Meanwhile, this treatment also enhanced the average well-color development, Shannon index, and McIntosh index, but decreased the Simpson index. Additionally, the average volume growth rate and relative water content of leaves reached their maximum using 60% irrigation with super-absorbent polymers, which was significantly higher than other treatments. However, using 30% irrigation with super-absorbent polymers, had a smaller effect on rhizosphere soil and volume growth than 60% irrigation with super-absorbent polymers. Therefore, using an appropriate water-saving irrigation measure (60% conventional border irrigation with super-absorbent polymers) can help to improve enzyme activities and microbial diversity in the rhizosphere soil while promoting the growth of poplar trees. [ABSTRACT FROM AUTHOR]

The self-healing cement used in oil wells aims to provide long-term interlayer isolation by enabling the cement system to repair itself. This paper compared the absorption properties of 2-acrylamido-2-methyl propanesulfonic acid (AMPS)-based superabsorbent polymer (SAP) and acrylic acid (AA)-based SAP in water and cement slurry filtrate. The effect of cement slurry filtrate on the water absorption properties of the two SAPs was evaluated. The results showed that the calcium ions in the cement slurry would crosslink with the carboxyl groups in the AA-SAP, increasing the crosslink density and greatly reducing its absorption rate in water. Compared to AA-SAP, AMPS-SAP is more suitable for oil well cement slurries. AMPS-SAP can help reduce the fluid loss of cement slurry. The addition of 0.4% AMPS-SAP in cement slurry results in a 64 mL decrease in fluid loss. The properties (rheological properties, thickening time, and compressive strength) of cement slurry meet the requirements for well cementing construction. [ABSTRACT FROM AUTHOR]

Superabsorbent bio-aerogels were developed from TEMPO-oxidized cellulose nanofibers (isolated from vegetable lignocellulosic residues) and two different commercial chitosan reactants (low and high molecular weight) by polyelectrolyte complex formation at room temperature. The materials were designed with the aim to provide useful, bio-based, and environmentally friendly food packaging supplies able to successfully replace those currently used that are made of synthetic and non-biodegradable polymers. Three different thickness values were considered, and two different aging times were employed, thus leading to twelve different bio-aerogel samples. Remarkably, no crosslink agents nor organic solvents were used. The bio-aerogel's components were strongly interacting through hydrogen bonding and electrostatic interactions, leading to highly porous and stable materials able to absorb high amounts of water and soybean oil. Then, the specific tests to visualize the material's potential use as food absorbent pads showed the following: (i) they were able to absorb simulated food exudates under a specific pressure in higher quantities (≈4000%) than some commercial pads (≈1600%); (ii) the materials have low to moderate antibacterial activities exposing better reduction effectiveness for Listeria monocytogenes than for Salmonella typhimurium; and (iii) the antioxidant properties were in general low. In the light of all the results achieved, the bio-aerogels prepared from H-CH with an aging time of 24 h and whose thickness was around 2.1 mm (H-10g-24) were selected as the most appropriate for the desired application. [ABSTRACT FROM AUTHOR]

Superabsorbent polymers (SAPs) can serve as effective internal curing agents in alkali-activated slag (AAS) systems, mitigating the risk of cracking. However, the influence of SAPs on the properties and microstructure of AAS systems is not yet fully understood. In this study, the effects of SAPs on the properties, reaction products, and internal moisture migration of AAS pastes were investigated. The water released by SAPs during curing supplemented the water consumption in the hydration process, maintained internal relative humidity, and reduced autogenous shrinkage by more than 80%. However, the addition of SAPs not only created voids in the hardened paste, as indicated by the mercury intrusion porosimetry (MIP) results, but also increased the microscopic pore volume of the paste. SAPs did not change the phase composition of AAS hydration products, but increased the differential thermogravimetry (DTG) peak corresponding to the main hydration product C(-A)-S-H gel at 28 days. The increase in chemically bound water in AAS pastes containing SAPs, along with the changes in the transverse relaxation time (T2) peak area corresponding to SAPs in the H1 low-field NMR results, likely are due to the gradual release of water during internal curing by SAPs. [ABSTRACT FROM AUTHOR]

To meet global food demand, reduce waste, and minimise environmental impact, the agricultural sector must improve its current practices on soil amendment, fertiliser encapsulation, and seed and crop protection. Super absorbent polymers (SAPs) are a class of polymeric materials that can absorb and retain large quantities of liquids/aqueous solutions compared to their own mass. Typically, SAPs are cross-linked to form three-dimensional hydrophilic networks, commonly known as hydrogels. Although SAPs can be synthesised from both synthetic and naturally sourced materials, for agricultural applications they are generally composed of synthetic polymers, due to their advantageous properties. These include higher water absorption rate and capacity, low cost, availability, durability, and mechanical performance. However, many of these systems utilise polyacrylic acid (PAA) and polyacrylamide (PAM) monomers which may have toxic effects on the nervous and respiratory systems of humans and animals. To ensure sustainable agricultural practices and maintain healthy long-term crop output, synthetic SAP usage must be greatly reduced. This review article aims to investigate alternative natural SAPs for agriculture and critically rationalise their adoption into the industry. Specific applications investigated include (i) soil amendment, (ii) fertiliser encapsulation, (iii) seed coating, and (iv) crop protection. [ABSTRACT FROM AUTHOR]

New methods are proposed for the verification of the presence of superabsorbent polymers (SAP) in freshly mixed concrete and estimation of SAP quantity. The methods are in general based on flushing concrete with excess water. They allow separating the light, water-sorbed hydrogel particles from the mineral components in the fresh concrete and making these particles available for further tests. Two types of tests are proposed: Test 1 serves for a visual verification of the presence of SAP (qualitative test), while Test 2 enables quantifying the mass of the collected SAP as a proxy of their concentration in concrete (quantitative test). Different procedures are proposed for these two test methods and their performance is evaluated. The testing procedures were scrutinized in an interlaboratory study carried out by 14 participants from 12 countries. All participating groups detected the presence of SAP in the mix using the qualitative procedures (Test 1). Based on this outcome, we suggest that this method should be applied in the field. In contrast, while most participants obtained reasonably reliable results with the quantification procedure of Test 2, some participants reported large errors. Therefore, the quantification method needs to be further refined, starting from the experience gained in this interlaboratory study. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a major health problem that affects the general population. Commiphora gileadensis (C gileadensis) is a small tree that grows in the Middle East. Objective: This study explored the effect of C gileadensis on blood glucose levels, lipid profile, and T lymphocytes subsets using flow cytometry. Methodology: Forty male mice were classified into four groups: negative control; diabetic nontreated; and two groups of diabetic mice treated with C gileadensis sap and acetone extract. The blood glucose levels, lipid profile, and HbA1c were estimated for each mouse in the four groups. Moreover, total lymphocytes, CD3+, CD4+, CD8+, and CD25+ subsets were estimated for all groups. Results: The blood glucose levels, triglyceride, total cholesterol, and HbA1c were significantly reduced in mice treated with C gileadensis sap and acetone extract compared with the diabetic group. Total lymphocyte and CD3+ were reduced in diabetic mice treated with C gileadensis sap and acetone extract compared with the untreated diabetic group (P <.05). In addition, CD4+ and CD8+ subsets were decreased in the same groups compared with the untreated one (P <.05). CD4+ CD25+ cells were decreased in all diabetic groups compared with the control group (P <.05). CD8+ CD25+ were increased in diabetic groups treated with C gileadensis sap and acetone extract compared with the untreated diabetic group (P <.05). Conclusion: The present study concludes that C gileadensis sap and acetone extracts reduce the blood glucose, HbA1c, and lipid profile in diabetic mice. Moreover, this herb has anti-inflammatory properties that may help in the normalization of glycemic index and prevent T1DM progression. [ABSTRACT FROM AUTHOR]

Water scarcity limits the survival and growth of planted-out seedlings in Ethiopia's semi-arid regions. Hydrogel, recently introduced in Ethiopia, is a super-absorbent polymer to reduce water stress. This study investigated its effect on the early survival and growth of Grevillea robusta seedlings in semi-arid areas. Relevant soil characteristics were analyzed. Four hydrogel levels (control, 3, 5, and 7 g/plant) were applied to the bottom of planting holes in a randomized complete block design with three replicates. Survival, Height, and Root Collar Diameter were measured at 6 and 14 months after planting. One-way ANOVA assessed hydrogel effects. No significant positive effects of hydrogel on survival or early growth compared to the control (0 g/plant) were observed in the sandy-loam soil. These findings suggest limited benefit under the study's specific conditions. Further research is crucial to explore the potential of hydrogels, considering broader ranges of application rates and methods, tree species, and environmental conditions. This knowledge may support forest restoration efforts in the face of severe land degradation, climate change, and variability in Ethiopia. [ABSTRACT FROM AUTHOR]