Rate Of Incorporation Research Articles

Research on the Mechanical Properties of Composite Grouting Materials Based on Ordinary Portland–Sulphoaluminate Cement

This study aimed to enhance the mechanical properties of calcium sulfoaluminate cement grouting materials (HCSA) by investigating the effects of ordinary Portland cement (OPC) content, the ratio of quicklime to gypsum, and the dosage of sodium aluminate on the compressive strength of the OPC-CSA composite system. The results indicate that as the OPC content increases, the compressive strength of the blended cement initially increases and then decreases, reaching a maximum at a 60% OPC replacement ratio within the experimental group. The addition of an appropriate amount of OPC to the CSA composite system effectively prevents the regression of compressive strength. With an increase in quicklime content, the compressive strength of the samples at various ages first increases and then decreases, with the optimal ratio of quicklime to gypsum found to be 2:8. Furthermore, sodium aluminate, used as an activator, when increased in dosage, leads to an initial increase followed by a decrease in the compressive strength of OPC-CSA samples, with an optimal incorporation rate of 0.75%, significantly enhancing the strength of the blended cement. In the orthogonal experiments, the dosage of sodium aluminate was identified as the most influential factor affecting the compressive strength of the composite grouting materials.

Prickly pear (Opuntia ficus-indica) dehydrated envelopes and seed cakes in Coturnix coturnix feed: effects on growth performance, carcass characteristics, meat quality and blood biochemical profiles.

The valorization of agro-industrial byproducts in domestic animal feed has the potential to reduce the cost of animal production. This trial was conducted to determine the effect of incorporating prickly pear byproducts (envelopes and cakes) as a partial substitute for corn and soybean meal in the diet of wheat quails (Coturnix coturnix) during their rearing period. Six hundred-day-old Coturnix coturnix quails of equal sex ratio (1:1), weighing on average 7 ± 0.5g, were randomly distributed into four groups, one control group and three experimental groups, according to the rates of incorporation of prickly pear cakes and envelopes, in sequential or nonsequential mode, in the different rearing phases. Each batch (150 subjects) was subdivided into five packs of 30 animals and randomly distributed according to the rate of incorporation (0%, 10%, 20% and 30%) of prickly pear envelopes and cakes. The live weight at 45 days and average daily gain (ADG1 - 45d) increased significantly with the introduction of byproducts in all rearing phases (SFCEPP). The carcass yield increased significantly (p < 0.05) with the introduction of byproducts in the finishing phase (FCEPP) and in all rearing phases (SFCEPP). The mineral content decreased significantly (p < 0.05) in all the experimental groups. The protein content increased significantly by 2 points on average when the two prickly pear byproducts were introduced in all rearing phases. The blood biochemical profile of each experimental batch was not influenced by the incorporated prickly pear byproducts. Prickly pear envelopes and cakes in wheat quail feed improve growth performance and meat quality, particularly when they are introduced in the finishing phase and in all rearing phases.

Effect of Magnesium Hydroxide on the Thermal Stability, Latent Heat and Flammability Properties of composite material based on Phase Change Materials

Abstract Polyurethane-Phase Change Materials (PU-PCM) composites are used for thermal regulation aiming to conserve and efficiently manage thermal energy. These materials combine the properties of PU, such as low thermal conductivity, low density and excellent mechanical properties as a thermal insulator, with the benefits of PCM allowing thermal energy storage, which greatly reduce energy consumption in heating and cooling. Adding a flame retardant to the PU-PCM composition improves fire resistance. The objective of this study is the preparation and characterization of a composite material based on PU rigid foam containing 30% by mass of commercial paraffin waxes as PCM, together with magnesium hydroxide as flame retardant. A series of samples were prepared by incorporating different percentages of Mg(OH)2, ranging from 1 % to 5 %, with and without the PCM. Various thermal and chemical characterization tests were carried out. The results indicate that the structure of the PU cells is not affected by the increase of the Mg(OH)2 incorporation rate. In terms of thermal properties, the addition of 1% flame retardant increases the latent heat from 25.9 J/g to 39.68 J/g. As the amount of Mg(OH)2 incorporated increases, the flame retardancy increases.

16O2 – 18O2 interface exchange study between gas phase and the BaFeO3–δ oxide

Studies of oxygen surface exchange kinetics for BaFeO3–δ oxide were performed using the oxygen isotope exchange method with pulsed supply of an isotopically enriched mixture (PIE) at the partial oxygen pressure 21.3 kPa in the temperature range of 350–600 °С. Oxygen surface exchange kinetics was considered in the framework of two-step model including two consecutive steps: dissociative adsorption of oxygen and incorporation of oxygen adatoms into the crystal lattice of the oxide. The rates of oxygen heterogeneous exchange (rH), as well as the rates of dissociative adsorption (ra) and oxygen incorporation (ri), have been calculated. The process of oxygen dissociative adsorption at the surface of BaFeO3–δ oxide was found to be the rate-determining step of the surface exchange. The appropriate models describing the oxygen exchange kinetics and possible mechanisms occurring in the system “gaseous oxygen – BaFeO3–δ oxide” were discussed.

Impact of strain relaxation on the growth rate of heteroepitaxial germanium tin binary alloy

The growth of high-quality germanium tin (Ge1–y Sn y ) binary alloys on a Si substrate using chemical vapor deposition (CVD) techniques holds immense potential for advancing electronics and optoelectronics applications, including the development of efficient and low-cost mid-infrared detectors and light sources. However, achieving precise control over the Sn concentration and strain relaxation of the Ge1–y Sn y epilayer, which directly influence its optical and electrical properties, remain a significant challenge. In this research, the effect of strain relaxation on the growth rate of Ge1–y Sn y epilayers, with Sn concentration >11at.%, is investigated. It is successfully demonstrated that the growth rate slows down by ~55% due to strain relaxation after passing its critical thickness, which suggests a reduction in the incorporation of Ge into Ge1–y Sn y growing layers. Despite the increase in Sn concentration as a result of the decrease in the growth rate, it has been found that the Sn incorporation rate into Ge1–y Sn y growing layers has also decreased due to strain relaxation. Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge1–y Sn y epilayers with tuned Sn concentration and strain relaxation.

Fluorescently probing anaerobic digester sludge: Measuring single-cell anabolic activity in methanogens (Methanosarcina and Methanothermobacter) with deuterium-labeled Raman analysis

This study addresses the challenge of obtaining in situ information on substrate utilization rates for individual microbial species in complex microbial communities such as anaerobic digester sludge. To overcome this hurdle, a novel approach combining doubly-labelled deuterium, fluorescence in situ hybridization (FISH) and Raman microspectroscopy was developed. The method enables quantitative determination of anabolic heavy hydrogen incorporation into FISH-targeted, exemplified by methanogenic cells from the genera Methanosarcina and Methanothermobacter.The deuterium incorporation rates ascertained by Raman red-shifting of C-Hx vibrational region to C-Dx vibrations, quantified through Raman peak area ratios, were compared for different carbon sources. Methanosarcina exhibited highest kinetic rates with acetate and propionate, while Methanothermobacter demonstrated faster incorporation under acetate and methanol supplementation.This groundbreaking study demonstrates the feasibility of obtaining quantitative metabolic rate information at a single-cell level using deuterium, FISH probes, and Raman microspectroscopy.

Controlled Vapor-Liquid-Solid Growth of Long and Remarkably Thin Pb1-xSnxTe Nanowires with Strain-Tunable Ferroelectric Phase Transition.

The Pb1-xSnxTe family of compounds possess a wide range of intriguing and useful physical properties, including topologically protected surface states, robust ferroelectricity, remarkable thermoelectric properties, and potential topological superconductivity. Compared to bulk crystals, one-dimensional (1D) nanowires (NWs) offer a unique platform to enhance the functional properties and enable new capabilities, e.g., to realize 1D Majorana zero modes for quantum computations. However, it has been challenging to achieve controlled synthesis of ultrathin Pb1-xSnxTe (0 ≤ x ≤ 1) nanowires in the truly 1D region. In this work, we report on a Au-catalyzed vapor-liquid-solid (VLS) growth of remarkably thin (20-30 nm) and sufficiently long (several to tens of micrometers) Pb1-xSnxTe nanowires of high single-crystalline quality in a controlled fashion. This controlled growth was achieved by enhancing the incorporation of Te into the Au catalyst particle to facilitate the precipitation of the Sn/Pb species and suppress the enlargement of the particle, which we identified as a major challenge for the growth of ultrathin nanowires. Our growth strategy can be easily extended to other compound and alloy nanowires, where the constituent elements have different incorporation rates into the catalyst particle. Furthermore, the growth of thin Pb1-xSnxTe nanowires enabled strain-dependent electrical transport measurements, which shows an enhancement of electrical resistance and ferroelectric transition temperature induced by uniaxial tensile strain along the nanowire axial direction, consistent with density functional theory calculations of the structural phase stability.

Incorporation of undissolved lime from previous applications can ameliorate subsoil acidity promptly and improve crop performance on sandy soils of the semi-arid regions of Western Australia

Abstract Background and aims Repeated surface application of lime for managing subsoil acidity is slow and ineffective, resulting in an accumulation of undissolved lime (carbonate) in the topsoil. We investigated the impact of the incorporation of undissolved lime into the subsoil to improve acidity and crop performance. Methods The undissolved lime in 2-cm layers of topsoil (0–10 cm) from three long-term experiments in Western Australia was measured. Both limed and unlimed topsoil with the acidic subsoil of the same profile was incubated at eight incorporation rates for six weeks, followed by growing barley and wheat in the incubated soil for two weeks to assess the impact on soil acidity and crop root architecture, respectively. Furthermore, a three-year-long field experiment was conducted following strategic tillage in limed and control plots to assess the impact on soil acidity and performance of wheat, canola and barley. Results A significant amount of undissolved lime was concentrated in the topsoil, amounting to 1.7, 1.8 and 1.3 t/ha for the limed plots at Wongan Hills, Northam and Merredin, respectively. Incubation of 5–25% topsoil after incorporation with the acidic subsoil was enough to ameliorate subsoil acidity and to improve root length density by up to 13-fold depending on undissolved lime content in topsoils and soil type. In the field experiment, the incorporation of undissolved lime also significantly improved subsoil acidity and canola performance. Conclusion We concluded that the incorporation of topsoil containing sufficient undissolved lime with acidic subsoil may offer a quick amelioration of subsoil acidity.

Effect of doping with iron and cations deficiency in the high conductive electrolyte La0.8Sr0.2Ga0.8Mg0.2O3–δ on oxygen exchange kinetics

The oxygen isotope exchange method was used to investigate the kinetics of the interaction between gaseous oxygen and LaGaO3-based oxides in a temperature range of 650 to 850 °C, with an oxygen pressure of 10 mbar. The stable isotopes of 18O/16O were used as labelled ions. The temperature dependencies of the heterogeneous oxygen exchange rate (rH), the oxygen dissociative adsorption rate (ra), the oxygen incorporation rate (ri), and the oxygen diffusion coefficient (D) were determined. A comparative analysis of the rH and D values for La0.8Sr0.2Ga0.8Mg0.2O3–δ was carried out with a view to identifying any similarities or differences when compared with the literature data on oxides with similar compositions. The effect of FeGa′ doping and the creation of an A-sublattice deficiency on the kinetic characteristics were investigated using the (La0.8Sr0.2)0.98Ga0.7Fe0.1Mg0.2O3–δ oxide as a case example. Correlations between the rate-determining step of oxygen exchange and the modification of the oxide composition were identified.

Living anionic copolymerization of 1,3-pentadiene isomers with alpha-methylstyrene in the presence of 2,2-di(2-tetrahydrofuryl)propane

The synthesis of statistical copolymers of alpha-methylstyrene (AMS) and 1,3-pentadiene (PD) isomers in the presence of 2,2-di(2-tetrahydrofuryl)propane (DTHFP) by living carbanionic polymerization was investigated in this paper. To the best of our knowledge, either AMS or PD monomer was rather difficult to homopolymerize in non-polar solvents without the help of polar additives even at high temperature due to its low ceiling temperature or relatively high electron cloud density of the conjugated CC double bond. However, the combination of RLi initiator and DTHFP regulator (0.1<DTHFP/Li < 0.5) allowed the rapid synthesis of the well-defined poly(AMS-stat-PD) with controlled molar masses (up to 32.5 kDa) and relatively narrow molecular weight distributions (1.10 < ĐMs < 1.52). Calculation of reactivity ratios by the Kelen–Tüdos method suggested that AMS copolymerized much more readily to with (Z)-1,3-pentadiene (ZP) than with (E)-1,3-pentadiene (EP) under the same conditions, whereas the EP/AMS copolymer exhibited much lower dispersity. 1H NMR results indicated that the polymer chain was found to be a mixture of 1,2-addition and 1,4-addition units, in the absence of 3,4-units. Kinetic experiments also showed that the apparent activation energy of EP/AMS copolymerization was slightly higher than that of the ZP/AMS case. To ensure complete conversion of the monomer, the feed ratio of AMS (fAMS) must be controlled to be within 0.3. In addition, the incorporation rate of AMS into the polymer chain increased with the increase in the feed ratio of AMS monomer. DSC curves showed that the Tg of the resulting copolymers increased gradually and could reach up to 25 °C (FAMS = 47). Based on the observation of the anionic statistical copolymerization behavior, an interpretation of the formation mechanism is presented here.

Comparative Evaluation of Micellization and Cellular Uptake of β-Carotene Affected by Flavonoids.

Based on in vitro digestion, micellar synthesis, and Caco-2 cell model, this study investigated the effects of typical flavonoids in citrus (naringenin, naringin, hesperetin, hesperidin, quercetin, and rutin) at different doses on the micellization and cellular uptake of β-carotene. In in vitro digestion, low-dose flavonoids enhanced β-carotene bioaccesssibility by regulating the stability and dispersibility of the intestinal medium, particularly quercetin, which significantly increased the bioaccessibility by 44.6% (p < 0.05). Furthermore, naringenin, hesperetin, hesperidin, and quercetin enhanced the micellar incorporation rate of β-carotene; however, naringin and rutin exhibited an opposite effect, particularly naringin, which significantly reduced it by 71.3% (p < 0.05). This phenomenon could be attributed to the high solubility of naringin and rutin in micelles, resulting in a competitive inhibitory effect on β-carotene. Besides, all treatments significantly enhanced β-carotene cellular uptake (p < 0.05) by promoting the expression of scavenger receptor class B type I and Niemann-Pick C1-Like 1.

Damming of streams due to the construction of a highway in the Amazon rainforest favors individual trophic specialization in the fish (Bryconops giacopinii).

In Amazonian streams, damming caused by road construction changes the system's hydrological dynamics and biological communities. We tested whether the degree of specialization in fish (Bryconops giacopinii) individuals is higher in pristine stream environments with intact ecological conditions than in streams dammed due to the construction of a highway in the Amazon rainforest. To achieve this, stomach content data and stable isotopes (δ13C and δ15N) in tissues with varying isotopic incorporation rates (liver, muscle, and caudal fin) were used to assess the variation in consumption of different prey over time. The indices within-individual component (WIC)/total niche width (TNW) and individual specialization were employed to compare the degree of individual specialization between pristine and dammed streams. The condition factor and stomach repletion of sampled individuals were used to infer the intensity of intraspecific competition in the investigated streams. The species B. giacopinii, typically considered a trophic generalist, has been shown to be, in fact, a heterogeneous collection of specialist and generalist individuals. Contrary to our expectations, a higher degree of individual specialization was detected in streams dammed by the highway. In dammed streams, where intraspecific competition was more intense, individuals with narrower niches exhibited poorer body conditions than those with broader niches. This suggests that individuals adopting more restricted diets may have lower fitness, indicating that individual specialization may not necessarily be beneficial for individuals. Our results support the notion that intraspecific competition is an important mechanism underlying individual specialization in natural populations. Our results suggest that environmental characteristics (e.g., resource breadth and predictability) and competition for food resources interact in complex ways to determine the degree of individual specialization in natural populations.

Using Gliricidia sepium prunings as green manure in a degraded ultisol ; effect on soil physical properties and yield of okra (Abelmuschus esculentus) in Abakaliki, southeast Nigeria

ABSTRACT Okra (Abelmoschus esculentus) is an important vegetable crop in southeast Nigeria, though at present there are only limited data available on the production in this area. A two-year field experiment was carried out in 2019 and 2020 cropping seasons to determine the effects of soil incorporation of different rates of Gliricidia sepium prunings (GS) as a green manure on soil consistency limits and physical properties, and yield of okra. The experiment was arranged as a randomised complete block design with four treatments and five replications. The treatments were as follows: control (C, no amendment); application of GS at 3 t ha−1 (3 GS), GS at 6 t ha−1 (6 GS); and GS at 8 t ha−1 (8 GS). The results showed significant increases (p < 0.05) in soil consistency limits in soil amended with GS relative to the control. The result also showed significant decrease in soil bulk density and increase in total porosity in soil amended with GS green manure. Soil water retention was significantly higher in Gliricidia sepium–amended plots. The dry pod yield of the okra increased significantly with the incorporation of the Gliricidia sepium green manure, though the differences in the yield between treatments with 6 and 8 t ha−1 rates of incorporation were not significant. Using GS as a green manure improved the consistency limits and physical properties of the soil and resulted in enhanced okra yields.

Synthesis of CuO Thin Film Incorporated with Nanostructured Nd2O3 Deposited by Pulsed Laser Deposition for Ammonia Sensing Applications

This study involved depositing thin films of copper oxide (CuO) and copper oxide films incorporated with neodymium oxide (Nd2O3) in various weight ratios using the pulsed laser deposition technique to fabricate an ammonia gas sensor. The characteristics of the developed films were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and photoluminescence spectroscopy (PL) techniques. The study investigated the impact of incorporating Nd2O3 into the CuO film on its sensing characteristics. The X-ray analysis revealed a polycrystalline structure of CuO with a crystal size of 19 nanometers. Furthermore, incorporating CuO and Nd2O3 formed a mixed phase comprised of both CuO and Nd2O3. The average crystallite size varied with the Nd2O3 incorporation rate from 19[Formula: see text]nm to 14.7[Formula: see text]nm. With increasing Nd2O3 incorporation ratios, the surface morphology changed from smooth to spherical-like nanostructures, and the average particle sizes varied from 28[Formula: see text]nm to 130[Formula: see text]nm. The PL spectrum analysis results confirmed that the incorporation of Nd2O3 resulted in a change in the peak intensity of the PL spectrum, with a significant increase in the peak associated with oxygen vacancies, contributing to the improvement of the sensor response. The incorporation of Nd2O3 greatly enhanced the sensitivity of the as-deposited CuO film. The sample with 5 wt.% Nd2O3 exhibited the maximum sensitivity, reaching 180% against 79 ppm NH3 at a working temperature of 50[Formula: see text]C.

Dynamic Activity and Stability of Transition Metal (oxy)Hydroxide Oxygen Evolution Electrocatalysts Under Steady and Intermittent Operation

The oxygen evolution reaction (OER) plays a critical role in several energy conversion technologies, requiring catalysts that combine high activity with stability for successful commercialization. Catalysts from first-row transition metal oxides have garnered considerable attention in this context. Their noteworthy OER activity and stability in alkaline environments position them as a more economical option than their counterparts in acidic media. However, recent studies have shown that these materials tend to experience significant dissolution issues and undergo changes in their chemical composition, a phenomenon observed even during steady-state operation.1–3 Addressing these challenges is essential for advancing commercial energy conversion technologies, which often face intermittent loads and reverse currents. A deeper understanding of the dynamic reconstruction under fluctuating conditions is crucial for developing more durable and efficient electrocatalytic materials.4 In this work, we investigate the dynamic performance of nickel cobalt (oxy)hydroxide electrocatalytic films containing iron active sites in alkaline media under steady and intermittent operation. First, we systematically examine the changes in OER catalytic activity in a typical three-electrode configuration, focusing on the incorporation and redissolution of iron and cerium during different electrochemical conditioning methods. As shown in Figure 1a, conditioning using chronopotentiometry decreases the OER overpotential without significantly shifting the redox peak. In contrast, conditioning using cyclic voltammetry significantly shifts the redox peak position (Figure 1b). These differences are attributed to the (oxy)hydroxide film thickness, which forms in situ during conditioning and affects the Fe dissolution and incorporation rates based on the conditioning method.5 We use different analytical techniques to probe chemical transformations during conditioning. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are utilized to analyze compositional changes in the electrocatalytic films. Moreover, inductively coupled plasma mass spectrometry (ICP-MS) tracks metal dissolution.Next, we utilize an electrochemical flow electrolyzer with a zero-gap configuration, integrated with online ICP-MS and post-experimental TOF-SIMS and XPS, to study the reconstruction of these electrocatalysts under intermittent conditions. A NiFe anode operating in 6 M KOH with 1 ppm of Fe3+ shows a 40-mV change after 120 cycles of alternating low and high currents, including a simulated shutdown step (Figure 1c). This cell potential change, becoming more negative with continued cycling (Figure 1d), is attributed to the shutdown step. Our findings underscore how operating conditions affect the dynamic reconstruction of electrocatalytic materials, offering critical insights for developing more robust and resilient materials suitable for commercial applications.

Structural Bone Grafting with Reverse Shoulder Arthroplasty for Osteoarthritis with Severe Glenoid Bone Loss: outcomes using a long post

Severe posterior glenoid bone loss with glenohumeral osteoarthritis with an intact rotator cuff can be managed with reverse shoulder arthroplasty but requires lateralization and version correction to avoid potential complications, such as instability, notching and implant failure. Angled bone grafting with humeral head autograft can provide durable glenoid bone stock, but results have been mixed. The purpose of this study was to evaluate patient-reported and objective outcomes as well as complication and failure rates for patients who underwent angled humeral head autografting for severe retroversion. All patients who underwent a primary RSA with angled humeral head autograft and Stryker Tornier long central post baseplate for severe glenoid bone loss in the setting of glenohumeral osteoarthritis with an intact rotator cuff at our institution between November 2018 and February of 2022 were identified. Individuals with a primary diagnosis of osteoarthritis and preoperative glenoid retroversion of ≥30° were included. Patients undergoing revision procedures, planned two-stage arthroplasty were excluded. Differences in pre- and postoperative range of motion, as well as patient-reported outcomes were assessed. Intraoperative complications, postoperative complications, and re-operation rates were analyzed. A total of 24 shoulders in 23 patients (61% male), with a mean age of 65.6 years were included. Average preoperative retroversion was 37.4° (range: 30° - 51°). Mean follow-up was 2.9 years (range: 2 - 4.3 years). Significant improvements were found in flexion, abduction, and external rotation. Patient-reported subjective outcomes were excellent, with average ASES score of 93.6 and average SSV 93.8%. Sixteen (67%) shoulders received postoperative CT scans and all were found to have incorporated. Complications included one shoulder hematoma requiring incision and drainage without revision, and a post-traumatic fracture of the inferior glenoid screw at 11 months, requiring revision RSA with bone grafting. No atraumatic catastrophic failures occurred due to component loosening. This study suggests that using angled humeral head bone grafting is a good solution for version correction in extreme posterior glenoid bone loss. Significant improvements are reported in ROM, pain, and subjective functional scores, with excellent graft incorporation rates and a low complication profile at early follow-up. Further work should focus on gathering higher levels of evidence, detailed radiographic analyses and exploring humeral head bone grafting for other indications.

Engineering the Activity of a Template-Independent DNA Polymerase.

Enzymatic DNA writing technologies based on the template-independent DNA polymerase terminal deoxynucleotidyl transferase (TdT) have the potential to advance DNA information storage. TdT is unique in its ability to synthesize single-stranded DNA de novo but has limitations, including catalytic inhibition by ribonucleotide presence and slower incorporation rates compared to replicative polymerases. We anticipate that protein engineering can improve, modulate, and tailor the enzyme's properties, but there is limited information on TdT sequence-structure-function relationships to facilitate rational approaches. Therefore, we developed an easily modifiable screening assay that can measure the TdT activity in high-throughput to evaluate large TdT mutant libraries. We demonstrated the assay's capabilities by engineering TdT mutants that exhibit both improved catalytic efficiency and improved activity in the presence of an inhibitor. We screened for and identified TdT variants with greater catalytic efficiency in both selectively incorporating deoxyribonucleotides and in the presence of deoxyribonucleotide/ribonucleotide mixes. Using this information from the screening assay, we rationally engineered other TdT homologues with the same properties. The emulsion-based assay we developed is, to the best of our knowledge, the first high-throughput screening assay that can measure TdT activity quantitatively and without the need for protein purification.

Discrete element modelling of the effect of disc angle and tilt angle on residue incorporation resulting from a concave disc

Understanding crop residue behaviour during tillage is critical for improving performance of tillage tools for conservation agriculture. A laboratory experiment was conducted using a concave disc to incorporate corn residue into sandy loam soil. Dynamic attributes, including soil cutting forces and residue incorporation, were measured under different lengths (75, 125, and 200 mm) of corn residue at constant disc and tilt angles. A residue-disc-soil interaction model was developed using discrete element method (DEM). Model parameters were calibrated and validated using experimental data. The validated model was used to predict the dynamic attributes at different disc and tilt angles. Experimental results demonstrated a general increasing trend in draft force (FD) and residue incorporation rate (RI), as the corn residue length increased. The two calibrated model parameters, stiffness of soil particle and stiffness of soil-residue interface were 1.15 × 106 and 13.5 N/m respectively. The validated model had an average relative error of 9.0 % and 18.2 % for predicting RI and FD respectively, as compared with the measurements. Within the angle range of 10° to 30°, the FD and RI decreased as the tilt angle (α) increased, whereas increased as the disc angle (β) increased. The effects of β were more pronounced than those of α. The optimal angles were α = 20°, β = 25° which resulted in a minimum FD and a maximum RI. The results provided new insight into residue-disc-soil dynamics and could be used to guide the selection of disc operating parameters.

Enhancing Pavement Durability: Comparative Rheological Evaluation of Conventional and Rejuvenated Reclaimed Binders under Aging Conditions.

A drawback of recycled mixtures containing reclaimed asphalt is their increased stiffness, further worsened by the accelerated aging of binders in extreme weather conditions. Previous studies have shown that while rejuvenating agents can mitigate some of these issues by improving flexibility and reducing brittleness, they often present challenges, such as performance variability and the potential for rutting. This study aims to develop an optimal blend of reclaimed bitumen, a rejuvenating agent, and pure bitumen to achieve rheological properties similar to a control 35/50 pen-grade bitumen for road paving. Hence, the rejuvenated binders comprised 30:70 blends of reclaimed asphalt bitumen and 50/70 pen-grade bitumen, adding 0.2% to 0.6% of a rejuvenating agent by mass of the reclaimed asphalt. Sample testing included conventional penetration grade, softening point, and viscosity tests, followed by dynamic shear rheometer tests under unaged, short-term, and long-term aging conditions. The results show that the binder blend with 0.4% rejuvenator closely resembles the rheological properties of 35/50 pen-grade bitumen. This blend exhibits a 20% to 55% stiffness reduction for recycled mixtures with 30% reclaimed asphalt. Notably, the rejuvenated binders exhibited a similar level of aging resistance to the control bitumen, with a marginal difference of less than 5% in aging ratios. Meanwhile, large strain amplitude tests showed the importance of defining maximum rejuvenating incorporation rates in recycled mixtures to avoid rutting problems, where binders with 0.4% rejuvenator doubled the rutting potential (Jnr values). This innovative study highlights the potential for enhancing recycled mixtures' performance by evaluating rejuvenated reclaimed binders' rheology subjected to different aging conditions, thus contributing to sustainability in pavement construction.

136. Do the incorporation rate or the particle size of wheat change its nutritional value in broiler chickens?

136. Do the incorporation rate or the particle size of wheat change its nutritional value in broiler chickens?