Retention Capacity Research Articles

Anti-Obesity Effects of a Collagen with Low Digestibility and High Swelling Capacity: A Human Randomized Control Trial

Background/Objectives: Collagen is a protein formed by very long amino acid chains. When conveniently treated, it can incorporate water into the net, thus increasing its volume and mass. The present work aimed to evaluate the potential anti-obesity effects of bovine collagen that has been technologically treated to increase its water retention capacity in an acid pH medium, with the objective of inducing satiation. Methods: Collagen’s digestibility was tested with a pepsin digestion test. Its swelling capacity was tested in an acid pH medium simulating gastric conditions. Postprandial levels of ghrelin in response to collagen supplementation were tested in rats. In a randomized control trial, 64 subjects with overweight/obesity were allocated in two groups: supplemented daily with two protein bars enriched with collagen (20 g per day) for 12 weeks, or control group. Anthropometric and biochemical measurements were assessed in all the participants. Results: This collagen showed a low digestibility (<60%) and high swelling capacity (>1900%) in vitro. In humans with overweight and obesity, this collagen significantly reduced body weight, body mass index (BMI), systolic blood pressure (SBP), and fatty liver index (FLI) and increased fat-free mass when compared with the control group. A significant reduction in the sarcopenic index; total, troncular, and visceral fat (measured by DEXA); and serum leptin levels were observed in the collagen group at the end of the intervention, with no differences with respect to controls. Collagen reduced the sensation of hunger and increased fullness and satisfaction. In male Wistar rats, collagen decreased postprandial blood ghrelin levels. Conclusions: Collagen supplementation (20 g per day for 12 weeks) reduced body weight, BMI, waist circumference, fat mass, FLI, and SBP in humans with overweight and obesity, which might be related to the increased sensation of fullness and satisfaction reported by the volunteers after the intake.

Optimization of Ultrasonic Extraction, Functional Properties, and Antioxidant Activity of Naematelia aurantialba Polysaccharides

AbstractNaematelia aurantialba (N. aurantialba) is a fungus rich in polysaccharides with medicinal and edible properties. Polysaccharides are the main active components of N. aurantialba; however, their biological activities and functional properties have not been widely explored. In this study, the ultrasonic extraction process for N. aurantialba polysaccharides (NAP) is optimized, and the physicochemical, functional, and antioxidant activities of the homogeneous fraction (NAP) are investigated. The optimal extraction conditions are a liquid–solid ratio of 50 mL g−1, ultrasonic power of 430 W, ultrasonic time of 32 min, resulting in an extraction rate of N. aurantialba polysaccharides of 48.68% ± 0.83%. NAP has a molecular weight of 915 kDa. The monosaccharide composition of NAP is as follows: mannose (59.04% ± 0.12%), xylose (23.89% ± 0.03%), glucuronic acid (14.07% ± 0.24%), galacturonic acid (2.12% ± 0.02%), and glucose (0.76% ± 0.02%). NAP exhibites water and oil retention capacities of 14.62 ± 0.25 g g−1 and 23.73 ± 0.85 g g−1, respectively. Furthermore, NAP demonstrates favorable moisture absorption and retention properties. The results show that NAP has a significantly stronger antioxidant effect, as demonstrated by its concentration‐dependent scavenging of ABTS, DPPH, and hydroxyl radicals.

Precise Preparation of Supramolecular Spherical Nucleic Acids for Nucleolin-Targeted Gene Delivery.

Molecular spherical nucleic acids (m-SNAs) are a second generation of spherical nucleic acids (SNAs), which are of significance in potential application of targeted delivery of nucleic acids or gene regulation due to their defined molecular structures. Nevertheless, m-SNAs typically involve a single DNA sequence which greatly limits its functions as either targeting purpose or gene regulation. In response, we proposed here a third generation, supramolecular spherical nucleic acids (Supra-SNAs) with two different sequences to achieve both above-mentioned functions. Specifically, we constructed a series of supramolecular self-assembly structures by coupling a cell membrane receptor (i.e., nucleolin)-recognizing aptamer (AS1411)-modified adamantine as targeting probe and human epithelial growth factor receptor 2 (HER2) antisense-functionalized β-cyclodextrin to specifically inhibit the overexpression of HER2 proteins for gene regulations. In comparison to the m-SNA precursors, such Supra-SNA structures exhibited enhanced levels of resistance to nuclease degradation, cellular uptake, gene regulation capabilities and tumor retention capacity. We demonstrated that Supra-SNAs exhibited optimal cell suppression rates and cell apoptosis via a phosphatidylinositol 3-kinase/protein kinase B signaling pathway. The well-defined molecular structures provide an attractive platform for investigating interrelationship between structure and property at the molecular level.

Precise Preparation of Supramolecular Spherical Nucleic Acids for Nucleolin‐Targeted Gene Delivery

AbstractMolecular spherical nucleic acids (m‐SNAs) are a second generation of spherical nucleic acids (SNAs), which are of significance in potential application of targeted delivery of nucleic acids or gene regulation due to their defined molecular structures. Nevertheless, m‐SNAs typically involve a single DNA sequence which greatly limits its functions as either targeting purpose or gene regulation. In response, we proposed here a third generation, supramolecular spherical nucleic acids (Supra‐SNAs) with two different sequences to achieve both above‐mentioned functions. Specifically, we constructed a series of supramolecular self‐assembly structures by coupling a cell membrane receptor (i.e., nucleolin)‐recognizing aptamer (AS1411)‐modified adamantine as targeting probe and human epithelial growth factor receptor 2 (HER2) antisense‐functionalized β‐cyclodextrin to specifically inhibit the overexpression of HER2 proteins for gene regulations. In comparison to the m‐SNA precursors, such Supra‐SNA structures exhibited enhanced levels of resistance to nuclease degradation, cellular uptake, gene regulation capabilities and tumor retention capacity. We demonstrated that Supra‐SNAs exhibited optimal cell suppression rates and cell apoptosis via a phosphatidylinositol 3‐kinase/protein kinase B signaling pathway. The well‐defined molecular structures provide an attractive platform for investigating interrelationship between structure and property at the molecular level.

Exploring the Possibilities of Using Recovered Collagen for Contaminants Removal—A Sustainable Approach for Wastewater Treatment

Collagen is a non-toxic polymer that is generated as a residual product by several industries (e.g., leather manufacturing, meat and fish processing). It has been reported to be resistant to bacteria and have excellent retention capacity. However, the recovered collagen does not meet the requirements to be used for pharmaceutical and medical purposes. Due to the scarcity of water resources now affecting all continents, water pollution is a major concern. Another major field that could integrate the collagen generated as a by-product is wastewater treatment. Applications of collagen-based materials in wastewater treatment have been discussed in detail, and comparisons with already frequently used materials have been made. Over the last years, collagen-based materials have been tested for removal of both organic (e.g., pharmaceutical substances, dyes) and inorganic compounds (e.g., heavy metals, noble metals, uranium). They have also been tested for the manufacture of oil-water separation materials; therefore, they could be used for the separation of emulsified oily wastewater. Because they have been analysed for a wide range of substances, collagen-based materials could be good candidates for removing contaminants from wastewater streams that have seasonal variations in composition and concentration. The use of recovered collagen in wastewater treatment makes the method eco-friendly and cost efficient. This paper also discusses some of the challenges related to wastewater treatment: material stability, reuse and disposal. The results showed that collagen-based materials are renewable and reusable without significant loss of initial properties. In the sorption processes, the incorporation of experiments with real wastewater has demonstrated that there is a significant competition among the substances present in the sample.

Conceptual and Applied Aspects of Water Retention Tests on Tailings Using Columns

The water retention capacity of porous materials is crucial in various geotechnical and environmental engineering applications such as slope stability analysis, landfill management, and mining operations. Filtered tailings stacks are considered an alternative to traditional tailings dams. Nevertheless, the mechanical behaviour and stability of the material under different water content conditions are of concern because these stacks can reach considerable heights. The water behaviour in these structures is poorly understood, particularly the effects of the water content on the stability and potential for liquefaction of the stacks. This study aims to investigate the water retention and flow characteristics of compacted iron ore tailings in high columns to better understand their hydromechanical behaviour. The research used 5 m high columns filled with iron ore tailings from the Quadrilátero Ferrífero region in Minas Gerais, Brazil. The columns were prepared in layers, compacted, and instrumented with moisture content sensors and suction sensors to monitor the water movement during various stages of saturation, drainage, infiltration, and evaporation. The sensors provided consistent data and revealed that the tailings exhibited high drainage capacity. The moisture content and suction profiles were effectively established over time and revealed the dynamic water retention behaviour. The comparison of the data with the theoretical soil water retention curve (SWRC) demonstrated a good correlation which indicates that there was no hysteresis in the material response. The study concludes that the column setup effectively captures the water retention and flow characteristics of compacted tailings and provides valuable insights for the hydromechanical analysis of filtered tailings stacks. These findings can significantly help improve numerical models, calibrate material parameters, and contribute to the safer and more efficient management of tailings storage facilities.

Effects of Different Land Uses and Slope on Runoff and Soil Loss on the Loess Plateau of China

ABSTRACTThe Loess Plateau has one of the most serious areas of soil erosion in China; therefore, studying the effect of soil and water conservation measures on the erosion of loess soil slopes is important for land management and agricultural development. This study is based on 5 years of field runoff observations and rainfall data from 2015 to 2019. Correlation and regression analyses were used to study the runoff and sediment production of loess soil and its relationship with rainfall, slope and land use. The results show that > 80% of the erosive rainfall occurs mainly in July to August in the area. Runoff and soil loss from the plots differed substantially, depending on land use, soil conservation measures and slope degree. Bare plots experienced the highest soil loss rate of over 27 t/ha with higher runoff depth, followed by cultivated plots (4.55 t/ha), grass plots (0.43 t/ha), shrub plots (0.35 t/ha) and forest plots (0.13 t/ha). Among the four soil and water conservation measures, the runoff and sediment reduction benefits of forest and shrub plots were the highest. The runoff reduction benefit fluctuated at approximately 0.8, and the benefit of sediment reduction was ≈1. The overall performance was forest > shrubland > grassland > cultivated land > bare land, and the benefits of sediment reduction were greater than those of runoff reduction. Forests had the highest soil retention capacity on slopes from 5° to 25°, and forests on gentle slopes had the best water storage capacity. Shrub plots had the best water storage capacity when they were on steep slopes. Rainfall erosion forces were significantly and positively correlated (p < 0.01) with runoff depth and soil loss, making it the most significant rainfall indicator of sediment production. Under the same rainfall conditions, soil and water conservation measures are still required on bare slopes, land use is the main control factor for slope sediment production, and appropriate land use can greatly reduce the threat of slopes in terms of soil erosion. This study shows that soil and water conservation measures are imperative to prevent runoff and soil loss, especially for bare land without any measures; on steep slopes, a vegetation combination primarily featuring shrubs is expected to achieve greater benefits in reducing runoff and sediment. This study can provide a scientific basis for the management of vegetation measures and the implementation of soil and water conservation measures on loess soil slopes.

Physicochemical and Antioxidative Properties of Protein Hydrolysates from Residual Goat Placenta Extract by Two Different Methods.

Protein hydrolysates from the goat placenta provide multiple benefits, such as immune system enhancement, antioxidant activities, and reductions in uric acid levels. Despite these benefits, their industrial applications have been underexplored. This study aimed to prepare extract protein hydrolysates (GPERPs) from residual goat placenta extract (GPER) and assess their functional properties, focusing on how different drying methods influence these properties. The essential amino acid contents were 30.94% for the GPER and 34.11% for the GPERPs. Moreover, all the essential amino acids were present, and the amino acid score (AAS) for each exceeded 1.0 in the GPERPs. The foaming properties of the spray-dried GPERPs (95.56 ± 5.89%) were significantly greater than those of the freeze-dried GPERPs (49.13 ± 4.17%) at pH values of 4.0~10.0. The emulsion stability (ES) of the spray-dried GPERPs (453.44 ± 8.13 min) was notably greater than that of the freeze-dried GPERPs (245.58 ± 7.12 min). Furthermore, the water retention capacity (WRC) of the freeze-dried GPERPs (201.49 ± 6.12%) was significantly greater than that of the spray-dried GPERPs (103.35 ± 7.13%), except at pH 10.0 (101.44 ± 8.13%). Similarly, at pH values of 6.0, 8.0, and 10.0, the oil retention capacity (ORC) of the freeze-dried GPERPs (715.58 ± 12.15%) was significantly greater than that of the spray-dried GPERPs (560.56 ± 11.15%), although the opposite trend was noted under acidic conditions. In terms of the antioxidant activity, the ability of the goat placenta extract residual protein hydrolysates (GPERPs) to scavenge DPPH radicals and superoxide anion radicals increased with the increasing peptide powder concentration, and the maximum scavenging rates of the DPPH radicals (39.5 ± 0.56%) and superoxide anions (81.2 ± 0.54%) in the freeze-dried peptide powder were greater than those in the spray-dried peptide powder. These findings contribute to the understanding of the physicochemical and antioxidant properties of GPERPs under various drying methods and provide fundamental data for the development of functional foods based on GPERPs.

Selection of Wheat Miller's Bran Based on the Sub-aleurone Protein Content Allows Increase of the Quality of Bran-Enriched Bread.

Wheat miller's bran negatively affects the gluten network but contains the grain tissue with the highest gluten content, the sub-aleurone. Here, the aim was to investigate how sub-aleurone gluten proteins in miller's bran affect bran-enriched bread quality. A bread-making experiment was performed with six lab-scale-produced bran samples. These strongly differed in protein content (10.8-18.6%) but had a similar particle size (d50: 1266-1330 μm) and strong water retention capacity (0.71-0.80 mL of H2O/g). Bran protein content variation mainly originated from sub-aleurone protein content variation (10.7-26.2%). Incorporating the bran with the highest versus lowest sub-aleurone protein content increased the loaf volume by 22.4%. 99% of loaf volume variation could be explained by sub-aleurone protein content variation. Conclusively, sub-aleurone protein content is the most important factor regarding bran functionality in bread-making. This was strengthened using commercial bran. Therefore, bran selection based on (sub-aleurone) protein content could be a low-cost, low-effort opportunity for bran-enriched bread-making.

Advances in the Study of NO3− Immobilization by Microbes in Agricultural Soils

The extensive application of nitrogen (N) fertilizers in agriculture has resulted in a considerable accumulation of N in the soil, particularly nitrate (NO3−), which can be easily lost to the surrounding environments through leaching and denitrification. Improving the immobilization of NO3− by soil microorganisms in agriculture is crucial to improve soil N retention capacity and reduce the risk of NO3− loss. In this paper, we reviewed the significance of microbial immobilization of soil NO3− in soil N retention, the techniques to quantify soil gross microbial NO3− immobilization rate, and its influencing factors. Specifically, we discussed the respective contribution of fungi and bacteria in soil NO3− retention, and we clarified that the incorporation of organic materials is of vital importance in enhancing soil microbial NO3− immobilization capacities in agricultural soils. However, there is still a lack of research on the utilization of NO3− by microorganisms of different functional groups in soil due to the limited techniques. In the future, attention should be paid to how to regulate the microbial NO3− immobilization to make soil NO3− supply capacity match better with the crop N demand, thereby improving N use efficiency and reducing NO3− losses.

A composite anode based on intercalation and conversion mechanism for high-rate lithium-ion batteries

To increase the specific capacity and cycle stability of lithium-ion batteries at high current density, we have investigated the anode materials. Among them, black phosphorus has attracted attention because of its large theoretical specific capacity (2596 mA h/g). However, the moderate conductivity of black phosphorus itself makes it less effective. The addition of graphite to form P-C and P-O-C bonds with black phosphorus enhances the performance of the battery cell. Lithium ions are primarily stored in black phosphorus-graphite layered structural materials via an intercalation mechanism, which improves electrochemical performance at tiny current density but is inadequate for charge/discharge cycling at high current density. In addition, lithium ions also can undergo conversion mechanism with metal oxide materials (e.g. Tungsten trioxide). While this conversion mechanism enables more stable battery cycling at high current density, the specific capacity remains insufficiently high. Higher charge/discharge specific capacity and long cycle stability of lithium-ion batteries at high current density can be realized by the joint action of the two mechanisms. In this work, black phosphorus, graphite, and tungsten trioxide (BP/G/WO3) composites are prepared by ball milling method. A comprehensive series of electrochemical analyses reveals that the BP/G/WO3-532 electrode (BP, graphite, and WO3 mass ratio of 5:3:2) exhibits the most substantial enhancement in the cycling stability of lithium-ion batteries. The anode exhibits a high specific capacity of 1463.1 mA h/g at 6 A/g and presents a retention capacity of 1159.8 mA h/g after 300 charge/discharge cycles, indicating a high cycle stability and fast reaction kinetics. This result is mainly attributed to the joint action of two mechanisms of composites.

Preparation of PVA/EG-WG gel foam and its inhibition of coal spontaneous combustion

In order to solve the shortcomings of existing gel foam such as poor stability, low strength and weak water retention capacity, a novel gel foam was prepared. The optimal ratio of this gel foam was determined in this experiment, and its inhibition performance and inhibition mechanism were analyzed. The results showed that the gel foam had the optimal performance when the mass fractions of foaming agent, foam stabilizer, gelling agent, cross-linking agent, Polyvinyl alcohol (PVA) and Ethylene glycol (EG) were 0.8 %, 1 %, 8 %, 2.2 %, 3 % and 7 %. After the gel foam action, the peak CO content in the oxidation process of coal samples decreased by 56.17 %, the average inhibition rate increased by 18.67 %, and the activation energy before and after the dry cracking temperature increased by 3.08 kJ and 9.20 kJ. The characteristic temperature points were greatly improved compared with those of the raw coal, which effectively slowed down the exothermic rate of coal oxidation. Compared with the traditional gel foam, PVA/EG-WG gel foam can achieve the effect of coal spontaneous combustion inhibition by means of inhibition and oxygen isolation, cooling and chemical reaction, etc.

Synthesis and characterization of allyl mannitol cross-linker based novel hydrogel for capturing of toxic metal ions from aqueous solution

ABSTRACT Three grades of allyl-mannitol cross-linker-based hydrogel (AMCLHs hydrogel) have been synthesized with the help of acrylic acid and acrylamide monomers using a free radical co-polymerization technique. The three prepared grades of AMCLHs hydrogel have been referred to as AMCLHs-1, AMCLHs-2, and AMCLHs-3, respectively. The prepared AMCLHs hydrogels have been characterized by several analytical techniques viz. Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) analysis, point of zero charge (ΔpHPZC), analysis, and scanning electron microscope (SEM) analysis, respectively. The synthesized hydrogels have been utilized for the elimination of Cu2+ and Co2+ ions from wastewater. The properties of prepared AMCLHs hydrogels, i.e. swelling and water retention ratio have been studied in distilled water under optimized conditions. The maximum swelling ratio of the best grade of hydrogel (AMCLHs-1) has been found to be 400.5 g/g with the water retention ratio of 75.09% during 24 h. These findings indicate the AMCLHs-1 hydrogel has remarkable swelling and water retention capacity. The maximum metal ion removal efficiency of AMCLHs-1 hydrogel from aqueous solutions has been found to be 96.6% for Cu2+ and 94.2% for Co2+ ions under optimum conditions. The experimental data fitted well with the Langmuir and Freundlich adsorption models, revealing maximum adsorption capacities of 431.03 mg/g for Cu2+ ions and 414.93 mg/g for Co2+ ions, respectively. In addition, the rate for the adsorption of Cu2+ and Co2+ ions onto AMCLHs-1 hydrogel follows both Pseudo first and second-order kinetic models. The negative ΔG values indicate that the adsorption process occurs spontaneously, while positive ΔH values suggest that the adsorption process is exothermic in nature. The prepared AMCLHs hydrogel is reusable and exhibits high desorption efficiency with 87.63% for Cu2+ and 85.21% for Co2+ metal ions even after the fourth cycle. Overall, AMCLHs hydrogel is a cost-effective and reusable adsorbent that possesses a significant potential for heavy metal ion removal from aqueous solutions.

Sodium alginate-g-polyacrylamide hydrogel for water retention and plant growth promotion in water-deficient soils

Natural polymer-based hydrogels are preferred as soil water retention agents due to their inherent biocompatibility and biodegradability. Generally, these natural polymers are chemically modified by graft polymerization of vinyl monomers to improve their water absorption and retention properties. Among the polysaccharides used to prepare natural hydrogels, those based on sodium alginate (Alg) stand out for their high-water absorption and retention capacity, as well as for their ability to promote plant growth. The main objective of this study was to develop a biodegradable alginate-based hydrogel as a water retainer to promote plant growth under water deficit conditions. The synthesis was achieved by grafting poly(acrylamide) (PAM) onto Alg backbone, using bisacrylamide as chemical crosslinker and different ratios of alginate:acrylamide (Ac). In addition, Eucalyptus nitens seedlings were used as a model plant to evaluate the effect of alginate-g-polyacrylamide (Alg:PAM) hydrogel application to the growing medium on plant survival, growth, and physiological responses under both well-watered and water-deficient soil conditions. The maximum degree of swelling (65 g/g) was obtained for the hydrogel prepared. The pseudo-second order model described the water uptake kinetics of the hydrogel. The degradability of Alg:PAM hydrogel reached up to 85 % in 5 weeks in soil and occurs by breaking the glycosidic bonds of the alginate. The E. nitens seedlings cultivated with different doses of Alg:PAM hydrogel (4:1 Alg:Ac) showed higher values of height and root diameter relative growth, survival and photosynthetic responses in comparison to non-treated plants. The results indicate that Alg:PAM hydrogel (4:1 Alg:Ac) has promising applications in forestry as a water retention and seedling growth promoter under water deficient conditions.

Three-layered functionally specialized nest structures enhance strength and water retention in mounds of Globitermes sulphureus (Blattodea: Termitidae).

Termite mounds are a ubiquitous feature of savanna ecosystems, yet the mechanisms by which termites (Blattodea: Termitoidae) mitigate the challenges posed by seasonal drought and flooding through mound construction remain insufficiently explored. This study investigates the material properties, water retention capabilities, and resistance to raindrop penetration across three distinct layers of Globitermes sulphureus (Haviland, 1898) (Blattodea: Termitidae) nests. Our findings reveal a pronounced diversification and specialization of materials and functions across these layers. Specifically, the outer layer has decreased moisture permeability, the middle layer has enhanced resistance to water penetration, and the innermost layer has a high capacity for water retention. The integration of these functionally specialized layers provides a compelling evidence for explaining how these termites are able to adapt to the fluctuating environmental conditions characteristic of savanna ecosystems. Furthermore, this highlights the nest's buffering capability against environmental stressors. The complexity of this construction, marked by a level of self-organization rarely observed in the animal kingdom, underscores a significant instance of architectural ingenuity among non-human builders.

Coupled iron and heavy metal accumulation in karst soils in Southwestern China: Iron isotope perspective

Heavy metals (HMs) are abundant in the karst soils of Southwest China, posing significant health risks to millions of people. Iron (Fe) (hyr)oxides serve as critical carriers of HMs in these soils; however, the processes governing Fe oxide formation and transformation associated with HM accumulation during carbonate weathering in karst region is less understood. In this study, we present Fe isotope compositions from a carbonate–derived profile to investigate the major factors controlling Fe migration. In the saprolite layer, strong correlations between δ56Febulk and the proportions of extracted FeNH2OH.HCl or Feresidue fractions suggest that the formation of goethite and phyllosilicate may be responsible for variations in δ56Febulk. The positive correlations between δ56FeNH2OH.HCl values and HM concentrations in this layer suggest an enhanced capacity for HM fixation by goethite in these soils. In contrast, the fractionation of Fe isotopes in the soil layer appears to be influenced by vegetation, as indicated by the correlation between total organic carbon and δ56Febulk. The negative correlations between δ56Febulk values and HM concentrations in the soil layer likely indicate that vegetation litter enhances the retention capacity of Fe oxides for HMs. This study highlights the trajectory of Fe and its connection to HM accumulation in karst soil with high geological background levels.

Co-application effects of rice husk biochar and different types of nitrogen fertilizers on rice yield, yield components, and nitrogen use efficiency

The Nitrogen (N) recovery index in rice paddy soils has never been exceeded by more than 30%, regardless of using proven fertilizer management strategies and amounting to significant N being out of rice plant use. Biochar application and the newly released N biofertilizers (singly or in combination) increase the N use efficiency by increasing the soil nutrient retention capacity. Therefore, a two-year pot experiment was conducted to explore the effects of the co-application of rice husk biochar and nitrogen fertilizers on rice yield, yield components, and nitrogen use efficiency indexes. The applied treatments were rice husk biochar at three levels (0, 20, and 40 tha−1) and N fertilizers at three levels (0, chemical (Urea), and N-biofertilizer). The most effective combination treatments (200 kg N ha−1 in source of urea plus 40 tha−1 rice husk biochar) significantly (p ≤ 0.01) increased the grain yield (2.38 times), straw and biological yield (2.83 and 2.62 times, respectively), N content of soil N (59%), nitrogen uptake efficiency (2.92 times), and nitrogen internal efficiency (59%), whereas, nitrogen recovery efficiency decreased by about 52%. Moreover, the maximum increase in N content of grain and harvest index was recorded at combination application of 20 tha−1 biochar plus urea by about 48 and 15%, respectively. It can be concluded that the co-application of rice husk biochar and N fertilizers has substantial advantages over their single applications in terms of N fertilizer recovery, N uptake. Thus, it might be an effective way to enhance rice yield.

Influence of diagonal reinforcement in grouted vertical joints between precast concrete wall panels, part I: Experimental investigation

AbstractMulti‐storeyed buildings are constructed using precast concrete large panels. Although the resistance to lateral loads during an earthquake can be provided by the walls, the vertical joints between the panels remain the weak links. Conventionally, a grouted vertical joint between precast panels is achieved using minimum number of overlapping transverse horizontal U‐bars or looped wire ropes from the adjacent panels, with a holder bar at the overlap, and subsequent grouting of the gap. It was observed that under in‐plane lateral loads, the shear behavior of such joints, especially those with looped wire ropes, is brittle. This paper presents a study to improve the behavior of conventional joints by introducing diagonal reinforcement (DR). Toward this, 13 specimens were tested under monotonic loading and 2 specimens were tested under quasi‐static cyclic loading. The parameters investigated were the types of transverse joint reinforcement, types and strengths of diagonal reinforcement. The compressive strengths of panel concrete and joint grout were kept similar to industry practice. The specimens with DR showed substantial increase of the shear strength and load retention beyond the peak. The presence of conventional transverse joint reinforcement in addition to DR, increases the retention capacity of the joint. Thus, the behavior of a joint with DR was found to be stronger and more ductile.

Microchip gas chromatographic columns dedicated for space exploration: Stationary phase coating, setup optimization and evaluation of column performances

This work is the first part of a project aiming to specifically design gas chromatographic microcolumns for space exploration. In particular, this study explored the functionalization and characterization of silicon/glass microchip gas chromatographic columns designed with a serpentine-shaped channel having an internal square cross-section. This microcolumn can be connected using a robust fluidic manifold with removable capillary connections to a conventional gas chromatograph or implemented in a prototype instrument for space exploration. First, benchtop gas chromatographic system was optimized in terms of injector liner volume, internal diameter (I.D.) of the capillary connections and data frequency of detection to ensure an optimal evaluation of column efficiency. Junction capillaries of 100 μm I.D., a liner of 1.2 mm I.D. and a detection acquisition frequency of 100 Hz were found to be the optimal set-up and parameters. Moreover, the stationary phase coating velocity was slowed-down to increase column efficiency by 100 %. Then, the performances of a square cross-section capillary column were compared with those of a conventional circular cross-section column. The coating efficiencies were estimated at 55 % and 42 % for circular and square internal cross-section geometries respectively, demonstrating that the square section geometry did not affect significantly the column performances. Stationary phase films of different thicknesses, from 0.032 to 0.260 µm, were coated on different microchips of the same production batch to assess the influence of film thickness on the chromatographic performances. Microchips performance was evaluated through Golay's plots, and some of the microchips were also studied by optical microscopy. The efficiency and retention capacity of our microchip column is shown to be highly dependent on the film thickness (9,000 plates.m-1 with k = 0.12 for the thinnest film and up to almost 4,000 plates.m-1 with k = 0.93 for the thickest film). Finally, the coating process repeatability was validated by producing three identical microchips with RSD of 4.8 % for the average number of theoretical plates.

Improving yield and irrigation water productivity of green beans under water stress with agricultural solid waste-based material of compacted rice straw as a sustainable organic soil mulch

AbstractThis research aimed at water saving in irrigation by applying deficit irrigation using two strategies, standard drip and partial root drying (PRD), while applying organic and plastic mulch over two growing seasons of green beans. A field experiment was conducted in 2022 and 2023, using four irrigation treatments supplying 100% of the irrigation requirement (IRg), 75% IRg, 50% IRg, and 50% IRg—PRD, and four soil mulching treatments: uncovered soil (UC), plastic mulch (PM), rice straw mulch (RSM), and compacted rice straw mulch (CRSM). The combined effect of deficit irrigation strategies and soil mulching showed that the maximum irrigation water productivity (IWP) of 5.56 kg m−3 was achieved under 50% IRg—PRD & CRSM for both growing seasons, followed by 50% IRg—PRD & RSM and 50% IRg—PRD & PM, with 5.19 and 4.96 kg m−3, respectively. The highest yield of 8936 kg ha−1 was achieved with 50% IRg—PRD & CRSM, followed by 8914 kg ha−1 and 8898 kg ha−1 with 100% IRg & CRSM and 75% IRg & CRSM, respectively. The lowest yield of 6009 kg ha−1 was obtained with 50% IRg & UC. The highest soil moisture content was observed under 100% IRg & CRSM. The application of organic mulches was found to be particularly effective in conserving soil moisture due to enhanced infiltration, improved retention capacity, and suppression of weed growth, ultimately fostering optimal crop development and higher yield. The results of soil temperature variations beneath soil mulches showed that CRSM is effective in alleviating plant water stress, lowering the temperature below the cover and reducing water loss through evaporation from the soil surface. The combination of 50% IRg—PRD & CRSM produced plants with enhanced plant height, fresh and dry weight, leaf area, pod length, and green bean weight, as well as the highest vegetative growth indices. Generally, the organic mulching increased soil temperature, soil moisture, IWP, and green bean production.