Residual Ratio Research Articles

An emission model for inhalable chemicals from children's play mats based on partition coefficients

Inhalable chemicals found in children's play mats can be slowly released into indoor environments and consequently threaten human health. In this study, the partition coefficients of seven inhalable chemicals between play mats and air were calculated by headspace gas chromatography-mass spectrometry based on the law of conservation of mass and the principle of equilibrium of headspace bottles. Furthermore, an emission source model for the residual ratio of the inhalable chemicals in play mats was established. Most substances found in play mats have large partition coefficients owing to the complex void structure of the mats, which adsorbs a large number of organic pollutants. The partition coefficient is not only related to the boiling point and environmental temperature, but also the specific material and the adsorption of the organic pollutant onto the material. The emission source model for children's play mats developed in this study can characterize the decay of the inhalable chemicals over time. The data showed that after eight days of placing the play mat in a ventilated environment, the residual ratio of seven inhalable chemicals did not exceed 15 %.

Pollution sources apportionment and suitability assessment of Lah River, Ethiopia: Conjunctive application of multivariate statistical analysis and water quality index.

This study aimed to assess spatiotemporal water quality variation and its suitability for irrigation and domestic purposes in Lah River using the irrigation water quality index (IWQI) and the weighted arithmetic water quality index (WAWQI). The IWQI analysis result showed that the sodium absorption ratio, residual sodium carbonate, potential salinity, Kelly index, magnesium ratio, sodium percentage, and permeability index were found to be 1.07 mEq/L, -0.43 mEq/L, 0.8 mEq/L, 0.78 mEq/L, 43.01%, 42.95%, and 63.46%, respectively. The IWQIs revealed that the water quality of the river was appropriate for agricultural use during the dry season. Furthermore, the calculated WAWQI of the river water ranged from 123.13 to 394.72 during the wet season, indicating the high pollution levels in the Lah River and incompatibility for drinking purposes. On the other hand, the principal component analysis identified two pollution sources during the wet season and three during the dry season. In addition, the positive matrix prioritization model predicted the pollution source's contribution quite well with a signal-to-noise ratio of >2 and a residual error between -3 and 3 for both seasons. This study suggests that water quality of Lah River is degrading periodically necessitating proper pollution management.

Post-Voided Residual Ratio Does Not Predict Trifecta Outcome after Transurethral Resection of Prostate.

The purpose of this study was to assess the importance of the post-void residual (PVR) ratio (PVR ratio) in achieving a favorable trifecta outcome for patients suffering from lower urinary tract symptoms and benign prostatic enlargement (LUTS-BPE) who undergo transurethral resection of the prostate (TURP). Starting from 2015, a series of patients with LUTS-BPE who underwent TURP were included in a forward-looking study. These patients were assessed using the international prostate symptom score (IPSS) screening tool, uroflowmetry, and a transrectal ultrasound to measure prostate volume (TRUS). Both the PVR urine volume and the PVR ratio (PVR-R), which is the PVR as a percentage of total bladder volume (voided volume + PVR), were measured. The assessment of outcomes was based on the trifecta favorable outcome, defined as meeting all of the following criteria: (1) absence of perioperative complications, (2) a postoperative IPSS of less than eight, and (3) a postoperative maximum urinary flow rate (Qmax) greater than 15 mL/s. A total of 143 patients were included, with a median age of 70 years (interquartile range 65-73). Of these, 58% (83/143) achieved a positive trifecta outcome. Upon conducting a multivariate analysis, both IPSS and Qmax were identified as predictors of a positive trifecta outcome, whereas the PVR-R did not prove to be an independent predictor. In summary, it was found that preoperative IPSS and Qmax are indicative of a trifecta outcome following TURP, whereas PVR-R is not.

Analysis of fracture toughness deterioration and instability model of dangerous rock masses under freeze–thaw cycles

The instability of dangerous rock masses is primarily caused by the stress intensity factor at the primary structural plane exceeding the fracture toughness of the rock bridge section, which results in the propagation of fractures. Additionally, in cold regions, the fracture toughness of these rock masses gradually decreases due to freeze–thaw cycles. Initially, considering the deterioration of type I and type II fracture toughness in the rock bridge section and the frost heaving force between structural planes, an assessment model for the stability of dangerous rock mass under freeze–thaw cycles is established. Secondly, utilizing the theory of circular hole expansion, along with the Mohr-Coulomb yield criterion and maximum tensile stress criterion, a model is constructed to simulate the degradation of type I and type II fracture toughness in rock bridge segments under the influence of freeze–thaw cycles. The validity of this model was subsequently verified through experimental validation. Finally, through engineering case studies, the degradation pattern of the stability of dangerous rock formations under the action of freeze–thaw cycles was analyzed. The study reveals that the decreasing stability of dangerous rock mass under freeze–thaw conditions is intricately linked to the internal friction angle, elastic modulus, and initial tensile strength of the rocks. Notably, the long-term stability of hard and coarsely textured dangerous rock mass under such conditions generally improves. Conversely, the tensile strength of the rock bridge segment elevates, which is beneficial for the long-term stability of the rock mass. When the residual debris ratio exceeds 0.25, the instability of the rock mass deteriorates more modestly. To maintain long-term stability, managing debris loss or injecting fillers into the pores can be effective strategies.

Integrated crop-livestock effects on soil carbon sequestration in Benin, West Africa

In Benin, adaptation to climate change in the livestock sector has led cattle farmers to develop different livestock practices. Most research has focused on evaluating the effects of these practices on livestock productivity. However, information on the effect of these practices on carbon (C) sequestration in farmland soils is lacking. Soil C sequestration has been identified as a potential strategy to offset greenhouse gas emissions. Thus, the present study aimed at filling this gap. The calculation was one hand based on inventory data obtained from literature sources (excrement production of each cattle category, moisture content of each crop, ratio of crop residue to main product, and C content of the main product and excrement) and on the other hand on activity data (cattle herd size, manure applied, land use area, crop yield, and crop residues management) obtained from surveys carried out among 360 cattle farmers belonging to 3 cattle farming types. The results revealed that whatever the cattle farming type, annual C input from manure was higher (p˂0.05) than C input from crop residues. Annual C sequestration in farmland soil of farms integrating livestock with cereal-legume and forage crops was significantly higher (Type 2: 158.07 ± 1.79 kg C ha−1 year−1) followed by farms integrating livestock with cereal-legume crops (Type 1: 99.51 ± 0.95 kg C ha−1 year−1), which in turn had a higher value than farms practicing pastoral mobility (Type 3: 78.46 ± 0.70 kg C ha−1 year−1). These results highlight the potential for climate change mitigation through these farming practices. This is justified because the quantity of C sequestered in farmland soil of all cattle farming types was significant. Thus, for future research, it is necessary to include soil C sequestration in the calculations of farms' carbon footprint.

Comprehensive Analysis of PKD1 and PKD2 by Long-Read Sequencing in Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by heterogeneous variants in the PKD1 and PKD2 genes. Genetic analysis of PKD1 has been challenging due to homology with 6 PKD1 pseudogenes and high GC content. A single-tube multiplex long-range-PCR and long-read sequencing-based assay termed "comprehensive analysis of ADPKD" (CAPKD) was developed and evaluated in 170 unrelated patients by comparing to control methods including next-generation sequencing (NGS) and multiplex ligation-dependent probe amplification. CAPKD achieved highly specific analysis of PKD1 with a residual noise ratio of 0.05% for the 6 pseudogenes combined. CAPKD identified PKD1 and PKD2 variants (ranging from variants of uncertain significance to pathogenic) in 160 out of the 170 patients, including 151 single-nucleotide variants (SNVs) and insertion-deletion variants (indels), 6 large deletions, and one large duplication. Compared to NGS, CAPKD additionally identified 2 PKD1 variants (c.78_96dup and c.10729_10732dup). Overall, CAPKD increased the rate of variant detection from 92.9% (158/170) to 94.1% (160/170), and the rate of diagnosis with pathogenic or likely pathogenic variants from 82.4% (140/170) to 83.5% (142/170). CAPKD also directly determined the cis-/trans-configurations in 11 samples with 2 or 3 SNVs/indels, and the breakpoints of 6 large deletions and one large duplication, including 2 breakpoints in the intron 21 AG-repeat of PKD1, which could only be correctly characterized by aligning to T2T-CHM13. CAPKD represents a comprehensive and specific assay toward full characterization of PKD1 and PKD2 variants, and improves the genetic diagnosis for ADPKD.

Effect of moisture content on properties, microstructure and carbon sequestration of CO2-cured cement mortar mixed with chelator

Chelator has the effect of improving the mineralization curing degree of cement-based materials. However, the moisture content in the pores of concrete will affect the permeability and dissolution of CO2 as well as the complexation and migration of Ca2+ by chelator, thus influencing the performance of CO2-cured concrete containing chelator. To obtain optimal moisture content for CO2-cured cement mortar mixed with chelator (CMC), the effects of the residual water cement ratio (RW) on the properties, microstructure, and carbon sequestration of CO2-cured CMC was investigated in this paper. The findings showed that the reduction of RW was beneficial for improving the mechanical properties and impermeability of mineralization curing CMC, but excessive reduction of RW weakened the action effect of chelator on accelerating the development of compressive strength. The optimal RW for mineralization curing ordinary cement mortar was 0.15 to achieve the fastest development of its mechanical properties, while the optimal RW for CMC was 0.2. It was also found that chelator was beneficial for shortening the curing period of CO2-cured mortar by more than half. Chelator significantly improved the aperture structure of CO2-cured mortar with a RW of 0.2 and promoted the transformation of larger to smaller pores through increasing the porosity of pore size between 0.01 and 0.02 μm by 7.1% and decreasing the portion of pores above 1 μm in the mortar by 24.2% after mineralization curing for 48 h. The reduction of RW was conducive to the permeation and diffusion of CO2, significantly enhancing the capacity of carbon sequestration of CMC. The RW was decreased from 0.5 to 0.2, and the carbon sequestration rate of CMC was increased by 551.6% after 48 h of mineralization curing. Meanwhile, compared to CO2-cured ordinary cement mortar, the carbon sequestration rate of CMC could be increased by 9.7% and 12.1% after 4 h and 48 h of curing, respectively.

Study on fatigue performance of asphalt mixture in service life based on accelerated loading test

To further study the fatigue damage evolution law of asphalt mixture in service period, the accelerated pavement testing (APT) of graded gravel base asphalt pavement and in-situ pavement was conducted. The full-scale test road of graded gravel base asphalt pavement was built, and the mechanical response sensors and temperature sensors were embedded. The fatigue damage test of the full-scale test road was conducted at 15°C through the accelerated loading test (ALT) equipment. The mechanical responses under the repeated wheel loadings were captured by the strain sensor at the bottom of the asphalt layer, and the deflections of the pavement under different cycles of wheel load were tested by Falling Weight Deflectometer (FWD). The fatigue damage model of asphalt mixture was established, and the accuracy of the model was verified by the accelerated loading fatigue test of in-situ pavement. The results show that asphalt layer bears an alternating effect of tensile and compressive strain, and when the wheel load is reduced or the driving speed increases, the tensile strain at the bottom of the asphalt layer decreases. As an evaluation index of fatigue damage of asphalt layer, the residual modulus ratio can accurately characterize the cumulative degree of fatigue damage. The modulus of asphalt layer shows an inverse S-type curve with the repeated wheel loadings. Based on the quantitative analysis of the whole process of fatigue damage of asphalt layer, a nonlinear damage evolution model of modulus attenuation of asphalt mixture was established, which would provide a reference for the study of pavement service performance attenuation law in different climatic environments and structural compositions in the future.

Effect of Co-Doping of Al3+, In3+, and Y3+ on the Electrical Properties of Zinc Oxide Varistors under Pre-Synthesizing BiSbO4.

Under the premise of using the solid-phase method to pre-sinter Bi2O3 and Sb2O3 into BiSbO4 as a substitute for equal amounts of Bi2O3 and Sb2O3 in the formula, the effects of co-doping with In(NO3)3, Al(NO3)3, and Y(NO3)3 on the microstructure and electrical properties of ZnO varistors were studied. The experimental results show that with an increase in In3+-doped molar concentration, the leakage current of the ZnO varistor shows a rapid decrease and then a slow increase trend. However, the nonlinear coefficient is the opposite of it. With the combined effect of the rare earth element Y3+, the average grain size is significantly reduced, which leads to an increase in the voltage gradient. At the same time, a certain amount of doped In3+ and Al3+ is dissolved into the grains, resulting in a decrease in grain resistance and thus a low level of residual voltage. The varistor with 0.6 mol% In3+, 0.1 mol% Al3+, and 0.9 mol% Y3+ doping ratios exhibits excellent overall performance. The nonlinear coefficient is 62.2, with the leakage current being 1.46 µA/cm2 and the voltage gradient being 558 V/mm, and the residual voltage ratio is 1.73. The prepared co-doped ZnO varistors will provide better protection for metal oxide surge arresters.

A new global damage index for steel moment resisting frames based on two steps pushover analyses

This paper proposes a new global damage index (DI) to evaluate and quantify the overall damage state induced by near-fault ground motions to the steel structures. DIs are conventional tools that evaluate and quantify the level of damage caused by earthquake excitement. The proposed damage index is based on two steps pushover analyses, which use roof residual drift ratio and maximum base shear before and after the earthquake. Moreover, the proposed damage index was compared with several well-known damage indices. Six steel moment resisting frames from 6- to 21-story frames were used for the evaluation. The strength and stiffness degradation were applied to all models as well. The incremental dynamic analysis was performed on the frames for 36 near-fault ground motions (a total number of 3312 nonlinear time history analyses) in the OpenSEES platform. The results show that the proposed DI can evaluate the damage properly in the nonlinear zone and collapse area in any nonlinear modeling methods. In addition, the merits and drawbacks of the proposed and other evaluated DIs were also discussed, and some of those drawbacks are being studied by the authors to be overcome in future works. Moreover, the efficiency of the proposed DI is also compared with the other studied DIs and shows that the proposed DI is significantly more efficient. The selected OpenSEES example files for the present study are shared through the link provided in the text.

Finite element model analysis of long-term performance of composite anchorage based on double-material parameters

Carbon fibre-reinforced polymer (CFRP) tendons demonstrate the advantages of light weight, high strength, and superior corrosion resistance and have broad application prospects for long-span cable structures. However, given the low transverse shear strength of CFRP tendons, how to achieve long-term and reliable anchorage for CFRP tendons is a critical issue. The long-term performance (LTP) of a novel composite anchorage for CFRP tendon was assessed in this study. Then, a finite element model (FEM) with double-material creep parameters was established to reliably model the LTP experiment according to the creep parameters of the bonding medium and CFRP tendon. Finally, the effects of the free section tendon length, pre-tightening force, over-tensioning force, and elastic modulus of the bonding medium were analysed using the established FEM with double-material creep parameters. Results revealed no visible damage to the CFRP tendon and anchorage after the LTP experiment. The maximum tendon slippage was 0.054 mm, and the residual load ratio was 0.826. These phenomena indicate that the novel composite anchorage has excellent LTP. The FEM modelling results based on double-material creep parameters were in good agreement with the experiment results. The residual load ratio calculated by the FEM was 1% lower than the experimental value. Through the parameter analysis, the residual load ratio of the specimen was effectively improved under longer free section tendon condition, but tendon slippage increased to a certain extent. In addition, the LTP of the composite anchorage can be effectively improved by appropriately decreasing pre-tightening force and over-tensioning force. When the over-tensioning force was 1.4 times the test load, the tendon slippage was reduced by 34.2%, and the residual load ratio increased by 4.8%. The greater elastic modulus of the bonding medium in the range of 2.1 GPa–3.1 GPa, the worse the LTP of the composite anchorage.

Web‐shear capacities of composite hollow‐core slabs with core‐filling and topping concretes

AbstractThis paper presents an experimental shear test performed to investigate the web‐shear capacity of composite hollow‐core slabs (HCS) with cast‐in‐place (CIP) concrete. Five HCS specimens are fabricated, and the presence of a topping slab and number of cores strengthened by core‐filling concrete are set as key test variables. The shear force–displacement responses of the specimens, patterns of cracks occurring in the HCS and filled cores, strain behavior of stirrups, and composite action between the HCS and CIP concrete are measured and analyzed comprehensively. In addition, the web‐shear capacity of the composite HCS with CIP concrete is calculated based on elasticity theory and the transformed area method, in which the residual stress ratio factor is introduced to reflect the shear contribution of the core‐filling concrete after its shear cracking. Moreover, a practical equation is proposed to allow structural engineers to easily perform the shear‐strengthening design of HCS via the core‐filling method. The detailed model and the simplified equation accurately evaluate the web‐shear capacities of the HCS specimens.

Facile crosslinking of PVA scaffolds using quercetin for biomaterial applications

Polyvinyl alcohol (PVA) is water soluble and biodegradable polymer known for its biocompatibility, low protein adhesion and minimal toxicity. However, inadequate mechanical stability limits its usage in various biomedical applications. This study explored the usage of quercetin as a promising crosslinking agent for PVA to significantly improve mechanical strength and water resistance. PVA was crosslinked with four concentrations of quercetin in ratios (1:0.005, 1:0.01, 1:0.015, 1:0.02 w/w). Scaffolds of uniform thickness (0.5 mm) were prepared using freeze-drying technique. The crosslinking efficiency and durability of PVA and PVA-quercetin scaffolds were studied based on residual weight ratio upon swelling, thermogravimetric, and Fourier Transform Infrared (FTIR) spectroscopic analysis. Results indicate that PVA-quercetin (1:0.02) showed better crosslinking efficiency with enhanced stability when compared with uncross-linked PVA which was further confirmed by the reduction of solubility in water which is substatiated by lower hydroxyl peak at 3200 cm−1. Further, the present work describes a facile methodology to crosslink PVA for developing a biomaterial with the potential antioxidant ability of quercetin.

Multisource Sparse Inversion Localization with Long-Distance Mobile Sensors

To address the threat posed by unknown signal sources within Mobile Crowd Sensing (MCS) systems to system stability and to realize effective localization of unknown sources in long-distance scenarios, this paper proposes a unilateral branch ratio decision algorithm (UBRD). This approach addresses the inadequacies of traditional sparse localization algorithms in long-distance positioning by introducing a time–frequency domain composite block sparse localization model. Given the complexity of localizing unknown sources, a unilateral branch ratio decision scheme is devised. This scheme derives decision thresholds through the statistical characteristics of branch residual ratios, enabling adaptive control over iterative processes and facilitating multisource localization under conditions of remote blind sparsity. Simulation results indicate that the proposed model and algorithm, compared to classic sparse localization schemes, are more suitable for long-distance localization scenarios, demonstrating robust performance in complex situations like blind sparsity, thereby offering broader scenario adaptability.

Matrix-based predictive model of residual drift and analytical resilience design approach for self-centering columns

Residual displacement serves as a crucial indicator in evaluating the safety and reparability of structures following seismic events. As a novel self-centering structure, the unbonded prestressed reinforced concrete (UBPRC) column has demonstrated its effectiveness in reducing residual displacement. However, there remains a lack of quantitative research concerning the influence of various structural and material parameters on residual displacement. For the quick and convenient evaluation of the seismic performance and resilience of UBPRC columns, in this paper, the influence of various parameters on the residual drift ratio of UBPRC columns was investigated by establishing a logarithmic linear relationship between the parameters and the residual drift ratio. These parameters include the longitudinal reinforcement and concrete strength (fy and fc), reinforcement ratio of longitudinal and transverse (ρl and ρs), prestressed strand ratio (ρp), aspect ratio (Ar), axial load ratio (αc), and prestressing force ratio (αps). Among the two parameters related to prestressed strands, increasing the prestressing force ratio significantly reduces RDr, while the influence of the prestressed strand ratio on RDr is relatively small. On this basis, a matrix-based probabilistic predictive model for the residual drift ratio was established. According to various physical parameters, the proposed mathematical model accurately predicts the residual drift ratio and describes the influence of each parameter on it. Furthermore, an analytical resilience design approach was proposed, and an analytical expression in matrix form for a multi-parameter resilience design was derived. Lastly, the impact of parameters on the damage state was investigated, and the range of parameter values under investigation was established, according to the analytical resilience design approach.

Turning Waste into Wealth: Utilizing Trichoderma’s Solid-State Fermentation to Recycle Tea Residue for Tea Cutting Production

Trichoderma is a widely recognized plant-growth-promoting fungus that has been extensively utilized in various agricultural applications. However, research on the economic production of Trichoderma spores and their effects on tea cuttings must be further advanced. In this study, T. guizhouense NJAU 4742 (NJAU 4742) emerged as a growth-promoting strain for tea cuttings, and the spore-production conditions of NJAU 4742 attained through solid-state fermentation (SSF) using tea residues were optimized. In a pot experiment, nursery substrates containing different concentrations of NJAU 4742 spores were tested for their influence on tea cutting growth and the rhizosphere fungal community. The optimal conditions for spore yield were determined as a 7:3 (w/w) ratio of tea residue to rice bran, a material thickness of 3 cm, an inoculum concentration of 15% (v/w), and an incubation time of 4 days, resulting in a spore count of 1.8 × 109 CFU/g. Applying NJAU 4742 spore products significantly increased the biomass of tea cuttings and influenced the fungal community composition. Moreover, higher concentrations of NJAU 4742 spores yielded better growth performance, and applying nursery substrate with 1.0 × 107 CFU/mL spores was the most economically viable option. Notably, among the top ten fungal genera with the highest relative abundance, Trichoderma showed a positive correlation with the fresh weight of tea cuttings, while the others exhibited a negative correlation. Overall, utilizing tea residue for SSF to produce NJAU 4742 was a feasible approach, and the application of NJAU 4742 spores enhanced the growth of tea cuttings by increasing the relative abundance of Trichoderma.

Biodegradation of sugarcane trash into substrates of utilizable products using lignocellulolytic microorganisms

Biodegradation of sugarcane trash was conducted using lignocellulolytic microorganisms, Bacillus subtilis (MW715021) and Schizophyllum commune (MW720154) strains. Throughout the biodegradation process, various physicochemical, biochemical, and microbial parameters were monitored. The weight, organic carbon, and C:N ratio of the sugarcane residue progressively decreased from 20 to 120 days of incubation. Among different treatments, T7 (Sugarcane trash + Bacillus subtilis + Schizophyllum commune) exhibited significantly the lowest weight, organic carbon, and C:N ratio of 61.60 g, 17.85%, and 13.02, respectively. The pH of the substrate decreased slightly at the initial period of biodegradation then it increased slightly and became stable at near about neutral pH. The Electrical Conductivity (EC) of the substrate was increased with the advancement of incubation periods. The Total Kjeldahl Nitrogen (TKN) content of the substrate increased with the duration of incubation. A higher TKN content of 1.37% was recorded in T7 on 120 days of incubation. The nutrient content (P2O5, K2O, Fe, Mn, Zn, and Cu) of the substrate was increased with the advancement of the decomposition period. The cellulose and lignin content was reduced from 40.78 to 21.54 % to 23.16 and 10.84 %, respectively in T7. Lignocellulolytic enzymes i.e. cellulase, laccase, lignin peroxidase, and manganese peroxidase were increased at initial degradation periods up to 60 days then it declined at a later stage of biodegradation. The microbial population increased with incubation periods up to 60 days then after it was declined at a later stage of biodegradation.

MgAl2O4–C refractories with balanced properties for a delivery device used in the double-roll thin strip continuous casting

To realize the double-roll thin strip continuous casting process for the production of high-quality steels, it is necessary to seek a new type of refractory material tailored for delivery device employed in this process. Therefore, the present study aimed to design and prepare MgAl2O4–C refractories for this purpose as well as to study their physical and mechanical properties, thermal shock resistance, oxidation kinetics, and to perform molten steel experiments after pre-oxidation treatment. The results of the present study demonstrated that the specimens could maintain high mechanical and thermal shock properties even after pre-oxidation treatment. After pre-oxidation at 1100 °C/1 h, the cold compressive strength of the specimen reached 17.63 MPa, with a residual strength ratio (thermal shock resistance) of 77.99%. Analysis of oxidation kinetics based on the shrinking core model indicated an increase in the effective diffusion coefficient and complete oxidation time with higher pre-oxidation temperature. Pre-oxidation of MgAl2O4–C refractories has been shown to be effective in reducing carbon penetration into the molten steel from carbon-containing refractories, thus maintaining the stability of the molten steel composition. This effect was attributed to enhanced contact and wettability between the steel and refractories, an augmented thickness of the pre-oxidized decarburized layer, the formation of a dense magnesium oxide layer, and the emergence of the MgAl1·9Fe1O4 phase. Consequently, an MgAl2O4–C refractories designed for the delivery device was proposed along with anticipated applicability in the double-roll continuous casting process.

Field-induced interfacial instabilities in a two-phase ferrofluid flow

Forming a stable ferrofluid and non-magnetic interface in a microchannel is essential for biomedical applications with two miscible aqueous solutions. Here, we report the interface profile and its instability of aqueous ferrofluid and water co-flow in a microchannel under the influence of a magnetic field. The scaling law related to diffusion width and dimensionless Pe number is introduced by solving the momentum and diffusion equation and combining the experimental results. It is found that the dimensionless number of diffusion width δ/h ∝ X/Peα, when core flow concentration cf, residual magnetic flux density Br, sheath flow and core flow ratio Qw/Qf, and core flow velocity Qf are changed, α is 0.633–1.071, α ∝ Qβ, β = −0.059,0.147, 0.019 and −0.101, respectively. Altering the core flow velocity and magnetic field intensity can quickly impact the interface's stability by improving the transport efficiency by 32.9 % and counteracting the impacts of material diffusion by 51.8 %, respectively. Elevating the proportion of sheath flow to core flow and magnetic field will impede the diffusion of core flow. This will result in a drop of 11.9 % in the magnetic convection effect and a 20.8 % counteraction of material diffusion effects.

Assessment of milk metabolites as biomarkers for predicting feed efficiency in dairy sheep

Estimating feed efficiency (FE) in dairy sheep is challenging due to the high cost of systems that measure individual feed intake. Identifying proxies that can serve as effective predictors of FE could make it possible to introduce FE into breeding programs. Here, 39 Assaf ewes in first lactation were evaluated regarding their FE by 2 metrics, residual feed intake (RFI) and feed conversion ratio (FCR). The ewes were classified into high, medium and low groups for each metric. Milk samples of the 39 ewes were subjected to untargeted metabolomics analysis. The complete milk metabolomic signature was used to discriminate the FE groups using partial least squares discriminant analysis. A total of 41 and 26 features were selected as the most relevant features for the discrimination of RFI and FCR groups, respectively. The predictive ability when utilizing the complete milk metabolomic signature and the reduced data sets were investigated using 4 machine-learning algorithms and a multivariate regression method. The Orthogonal Partial Least Square algorithm outperformed other ML algorithms for the FCR prediction in the scenarios using the complete milk metabolite signature (r2 = 0.62 ± 0.06) and the 26 selected features (0.62 ± 0.15). Regarding RFI predictions, the scenarios using the 41 selected features outperformed the scenario with the complete milk metabolite signature, where the Multilayer feedforward artificial neural network (r2 = 0.18 ± 0.14) and extreme gradient boosting (r2 = 0.17 ± 0.15) outperformed other algorithms. The functionality of the selected metabolites implied that the metabolism of glucose, galactose, fructose, sphingolipids, amino acids, insulin, and thyroid hormones was at play. Compared with the use of traditional methods, practical applications of these biomarkers might simplify and reduce costs in selecting feed-efficient ewes.