Dispersion Method Research Articles

Effect and mechanisms of type, content, and dispersion method of flash graphene on the rheological behaviors of fresh cement pastes

Flash Joule heating provides a facile, low-carbon, and cost-effective method for upscale graphene production, benefiting the application of graphene in modifying cement-based materials. Understanding the effect and mechanisms of flash graphene (FG) type, content, and dispersion method on the rheological behaviors of cement-based materials is essential for designing and controlling cement-based materials in different application scenarios. Therefore, this study explored the rheological behaviors of cement pastes with 2 different types of flash graphene at 4 different content levels (namely 0.1 wt%, 0.2 wt%, 0.3 wt%, and 0.4 wt% of cement mass) using 3 different dispersion methods (namely water reducer dispersion with ultrasonic treatment, dry mixing with water reducer, and mechanical dispersion with water reducer). The results indicated that the addition of FG generally increases the yield stress and plastic viscosity of fresh cement pastes. The water reducer dispersion with ultrasonic treatment and nano-boron doping shows a good effect in dispersing FG. The influence mechanisms of FG on rheological behaviors of fresh cement pastes are a competition between exert replacement, agglomeration, lubrication, and adsorption effects.

Propagation characteristics of show sea seismic wave in different underwater media

The propagation characteristics of sea seismic wave (SSSW) in different underwater media are different. This study mainly focuses on the propagation characteristics of SSSW in different underwater media to improve the detection ability of SSSW mines. The propagation of SSSW in different underwater media, including clay, sandy clay, sandstone, mudstone, hard stone, and dolomite, is simulated using the staggered grid finite difference method. The dispersive energy maps of different underwater media are extracted using the f-k dispersive energy extraction method. Compared with the results of Scholte wave dispersion characteristic equations, the simulation results are consistent with the theoretical results. At the same time, the attenuation law of the SSSW train is obtained. The results provide a theoretical basis for developing SSSW mine fuses.

Enhancing polyethylene‐based nanocomposites through ethylene plasma polymerization of carbon nanotubes and sequential ultrasound dispersion with melt mixing method

AbstractThis study investigates the enhancement of linear low‐density polyethylene (LLDPE) nanocomposites with multiwalled carbon nanotubes (CNT) at concentrations of 1, 3, and 6% w/w. To improve the interfacial interaction between the CNT and the polymeric matrix, CNT were treated using ethylene cold plasma (P‐CNT) in a rotary reactor. The incorporation of CNT into the polymer was carried out by a melt mixing process (MMP) and a sequential ultrasound dispersion method followed by melt mixing (UDM‐MMP). The thermal stability of nanocomposites with 6% P‐CNT increased by 45°C compared to pristine LLDPE. Electrical conductivity reached 2.5 × 10−2 S/cm for nanocomposites with 6% CNT. The elastic modulus increased from 519.52 MPa (LLDPE) to 714.63 MPa (6% CNT) and 795.43 MPa (6% P‐CNT), which further improving to 731.42 MPa (6% CNT) and 841.27 MPa (6% P‐CNT) using UDM‐MMP. Additionally, yield stress rose from 16.35 MPa to 21.28 MPa (6% CNT) and 22.06 MPa (6% P‐CNT), reaching 21.47 MPa and 22.28 MPa with UDM‐MMP. Tensile strength increased from 21.31 MPa to 25.15 MPa (6% CNT) and 25.9 MPa (6% P‐CNT), achieving 26.82 MPa (6% P‐CNT) with UDM‐MMP. These results highlight a significant improvement in conductivity, rigidity, and mechanical strength, emphasizing their potential for advanced applications.

Selective solid phase extraction of folic acid from tomato as a biological source with a magnetic molecularly imprinted polymer measured by fluorescence spectroscopy

AbstractA novel magnetic molecular-imprinted polymer (MMIP) was used to selectively extract folic acid directly from real samples. Folic acid was used as template molecule, Fe3O4/SiO2-3-triethoxysilyl-propyl-acrylamide as functional monomer, azobisisobutyronitrile as initiation, ethylene glycol dimethacrylate as crosslinker agent, and acrylamide as the secondary monomer in a mixed ethanol-water solvent. The effect of different parameters on the extraction efficiency was studied, and the optimum conditions were established as follows: the concentrations of crosslinking and template were fixed at 0.05 and 0.06 g, absorption percentage was 96.5, pH was adjusted to 8, and extraction time was 8 h with a temperature of 25 °C. By examining the effect of pH, we tried to investigate the effect of the amide groups that present in MMIP and its intermolecular hydrogen interaction with folic acid. After optimising the effective parameters in polymer synthesis and adsorption rate, a magnetic imprinting dispersive solid-phase extraction method combined with fluorescence spectrophotometry at λem = 367 nm (MMIP-DSPE-FL) was constructed for sensitive determination of folic acid in tomato samples. The limit of quantification (LOQ) and limit of detection (LOD) values were 30.00 ± 0.01 μg L−1 and 10.00 ± 0.03 μg L−1, respectively, after the MMIP-DSPE preconcentration. Three tomato samples were analysed to give recoveries in the range of 80.2–81.6%, with relative standard deviation values below 0.6% (n = 3). The prepared MMIP-DSPE showed high selectivity toward folic acid, which could be used six times without changing adsorption capacity. The adsorption isotherm of the folic acid-imprinted polymer pursued the Langmuir model (RL = 0.029), and the kinetics model followed pseudo-first-order (R2 = 0.9974).

Capability lignin from Acacia crassicarpa black liquor as an environmentally benign antibacterial agent to produce antibacterial and hydrophobic textiles

Recently, the growing health awareness of society on the utilization of fabrics has led to an increasing demand for natural-based antibacterial textiles. Lignin, a generous polyphenol compound in nature, is capable of preventing bacterial growth; in particular, it dwells bacteria closely together on human skin, such as Staphylococcus epidermidis, Bacillus subtilis, Propionibacterium acnes, and Staphylococcus aureus. However, the antibacterial properties of lignin are limited by factors such as the lignin concentration, source, and type of bacteria. This study aimed to evaluate the potency of lignin as an antibacterial agent for textiles. Moreover, the thermal properties and wettability of the textile after lignin coating were also investigated. This study showed that lignin isolation methods significantly contributed to the inhibition of bacterial growth in the clear zone diameter. In addition, the lignin structure, lignin concentration, and type of bacteria had notably different antibacterial effects. SEM images showed that lignin was successfully coated on the fiber, and the antibacterial textile was successfully fabricated with clear zones in the range of 0.1–0.5 cm against four different bacteria. Lignin did not significantly improve the thermal stability of the textile, as proven by the TGA results. After the HDTMS coating by dispersion method, the wettability of the lignin-textile improved to that of the hydrophobic material, with a contact angle greater than 119.05° with excellent antibacterial properties (clear zone of 0.1–0.43 cm).

Application of a Composite Based on Magnetite Nanoparticles, Graphene Oxide, and an Ionic Liquid for the Extraction of Bisphenol A from Bottom Sediments by the Matrix Solid-Phase Dispersion Method

Application of a Composite Based on Magnetite Nanoparticles, Graphene Oxide, and an Ionic Liquid for the Extraction of Bisphenol A from Bottom Sediments by the Matrix Solid-Phase Dispersion Method

Research of electrode materials for the creation of multifunctional current sources with increased capacity as a components of the energy sector of an efficient urban environment

As part of creating a comfortable and safe environment, constructing energy-efficient residential and industrial buildings and structures that meet modern requirements and standards, the development of the production of environmentally friendly renewable and new individual energy sources is becoming especially relevant. In this regard, there is a need to increase the energy capacity of electrochemical cells. Research has been carried out on the metallized conductive materials creation based on rolled carbon non-woven material “Busofit” with the sequential application of metal coatings of titanium and silver using ion-plasma sputtering and electric pulse dispersion methods. It has been shown that surface layer metallization of the electrode material with titanium can improve the electrochemical cell characteristics. Additional silver film deposition leads to further cell performance improvement. It has been confirmed that the multilayer structure interfacial resistance between the carbon and the current collector has a significant effect on the conductivity of the electrochemical cell and the stability of its operation. The contact area increase of the electrode with the electrolyte leads to an increase in the rate processes occurring on the electrode surface and in the near-electrode space, which opens up prospects for increasing the energy intensity of the electrochemical system. A significant capacity increase of a water-based capacitor structure is achieved by the formation of a nanostructured dielectric layer of potassium titanate in the interelectrode space. It has been confirmed that the cell voltage cycling helps to stabilize the processes occurring in the surface layer of the electrode material at the interface and determining the range of mechanisms for transmitting electrical energy, which makes it possible to achieve higher energy intensity of the samples. Improvement of technological solutions in the field of ion-plasma technologies and the use of new perspective nanostructured materials creates the prerequisites for the creation of advanced automation and energy supply systems with a higher resource, which expands the possibilities of their use in various construction projects.

Mechanical and piezoresistive performance of polymethyl methacrylate modified with carbon nanotubes for sensitive road surface

Piezoresistive materials, known for their mechanical adaptability and sensing capacity, hold the potential to be used as the materials for the sensitive surface layer in the digital twin of road systems. This study aims to investigate the mechanical and piezoresistive performance of a novel pavement material, a composite that comprises Polymethyl methacrylate (PMMA) as the matrix and carbon nanotubes (CNTs) as the conductive filler. Firstly, the composition and preparation process of CNTs-modified PMMA (CMP) were optimized via investigation on curing time, dispersion methods, and initiator content. Subsequently, the piezoresistive responses of CMP were analyzed within a loading range of 0 to 10 MPa by conducting linear increase compressive stress tests. Additionally, dynamic modulus tests and dynamic creep tests were employed to assess the mechanical and piezoresistive responses of CMP under equivalent vehicle loads. Results show that optimal properties are achieved when using ultrasonic methods to disperse CNTs, with a curing period of 72 h and an initiator content of 1.6 wt%. PMMA exhibits a lower modulus, reduced elasticity recovery and temperature sensitivity after modification with CNTs. And varying the CNTs content from 0.8 wt% to 1.2 wt% does not significantly affect the viscoelastic properties of CMP. The piezoresistive response of CMP under equivalent vehicle loads occurs in the first stage of the fractional change in resistance curve and is exclusively correlated with the tunneling resistance of adjacent CNTs. In this stage, CMP demonstrates higher sensitivity to heavy loads at lower CNTs content. The developed piezoresistive model based on tunneling resistance aligns with the experimental results. This study provides a basis for the performance study of CMP as a piezoresistive material in pavements, contributing to the design and development of sensitive surface layers in road systems.

Enhancing Polylactic Acid Properties with Graphene Nanoplatelets and Carbon Black Nanoparticles: A Study of the Electrical and Mechanical Characterization of 3D-Printed and Injection-Molded Samples.

This study investigates the enhancement of polylactic acid (PLA) properties through the incorporation of graphene nanoplatelets (GNPs) and carbon black (CB) for applications in 3D printing and injection molding. The research reveals that GNPs and CB improve the electrical conductivity of PLA, although conductivity remains within the insulating range, even with up to 10% wt of nanoadditives. Mechanical characterization shows that nanoparticle addition decreases tensile strength due to stress concentration effects, while dispersants like polyethylene glycol enhance ductility and flexibility. This study compares the properties of materials processed by injection molding and 3D printing, noting that injection molding yields isotropic properties, resulting in better mechanical properties. Thermal analysis indicates that GNPs and CB influence the crystallization behavior of PLA with small changes in the melting behavior. Dynamic Mechanical Thermal Analysis (DMTA) results show how the glass transition temperature and crystallization behavior fluctuate. Overall, the incorporation of nanoadditives into PLA holds potential for enhanced performance in specific applications, though achieving optimal conductivity, mechanical strength, and thermal properties requires careful optimization of nanoparticle type, concentration, and dispersion methods.

Preparation and Optimization of Beta-Sitosterol Nanosuspension-Loaded In situ Gel by Using Box-Behnken Model for the Treatment of Prostate Cancer

Introduction: Prostate cancer is the second most often occurring cancer in males and the fourth most common cancer overall. Beta-sitosterol (β-Sit), the most prevalent plant phytosterol found in several plant species, has been reported to have inhibitory effects against several malignancies. Even though β-Sit has considerable potential, its therapeutic uses are limited due to its poor aqueous solubility (<0.1mg/ml), low bioavailability (0.41%), and poor absorption from GIT. Nanosuspension is one of the most innovative approaches to address problems linked to low solubility and poor absorption. Method: In the present research work, β-Sit nanosuspension has been fabricated by nanoprecipitation- ultrasonication, followed by high-pressure homogenization (Panda plus 2000) employing HPMC E5 and poloxamer (188 and 407) as stabilizers, optimized using a Box-Behnken technique. Subsequently, in situ nano gel was prepared by dispersion method using gellan gum as an ionsensitive polymer by incorporating optimized nanosuspension. Results: The optimized nanosuspension was evaluated for various parameters and has been found to have an average particle size (137 ± 5.07 nm), zeta potential (-24±4.99), PDI (0.207), and improved solubility up to 5 folds, being suitable for systemic absorption through the nasal route. The optimized in situ gel was characterized and showed the desired viscosity, good spreadability, acceptable gelation property, and sufficient mucoadhesive strength to adhere to nasal mucosa after ionic interaction. The in vitro release of pure drug, nanosuspension, and the optimized gel was compared, and optimized in situ gel showed a maximum release of 91.41 ± 1.32% up to 8 hours. Conclusion: It was concluded that the in situ nasal nanogel could be the best possible approach to delivering β-Sit into systemic circulation for the treatment of prostate cancer.

Optimization of solid dispersion technique and gliclazide to carrier (PVP K30) ratio for solubility enhancement

Background and objective: Poorly water-soluble dugs provide less dissolution rate and bioavailability; hence, it minimizes the pharmacological effect of orally administered medications. Gliclazide is a sulfonylurea antidiabetic medication of the second generation, used to treat type II diabetes mellitus. It belongs to the class II drugs of biopharmaceutic classification system, indicating that it has high permeability and poor aqueous solubility. The aim of this study is to determine an optimum solid dispersion method and drug to carrier ratio to improve the solubility of gliclazide. Methods: Solid dispersions of gliclazide were formulated with polyvinyl pyrrolidone K30 using various drug to carrier ratios (1:1, 1:3, and 1:5) by utilizing kneading and solvent evaporation methods. Solubility and dissolution rate of solid dispersion formulas were compared with pure drug and co-ground mixtures. The formulations were further evaluated in terms of percentage of yield, drug content, FTIR, SEM, DSC, and XRD studies. Results: The highest solubility improvement of gliclazide was obtained at the ratio 1:5 of gliclazide and PVP K30 utilizing solvent evaporation method, solubility increased about 2.54 folds (98.299 ± 5.77 µg/ml) as compared to pure gliclazide (38.739 µg/ml). Meanwhile, the greatest improvement in gliclazide dissolution rate was observed in the same solid dispersion formula that was about 105.76 % after 30 minutes. FTIR demonstrated no unwanted interaction between the drug and carrier. While, SEM, DSC, and XRD showed crystallinity of the drug was minimized and converted to amorphous form in solid dispersion formula. Conclusion: Based on the investigations of this study, it can be concluded that the drug to carrier weight ratios and preparation methods had the influence on the drug solubility and the release rate. The obtained data revealed that the solvent evaporation is the best method of solid dispersion for enhancing gliclazide solubility using PVP K30 with the ratio 1:5 of the drug and carrier.

GaN microdisks with a single porous optical confinement layer for whispering gallery mode lasing

This paper details the fabrication of GaN-based microdisks with a single porous n-GaN layer positioned beneath the multiple quantum wells region on a modified green light-emitting diode epiwafer. Simulations of the longitudinal light field distribution reveal effective confinement of the light field within the multiple quantum wells region due to the presence of the single porous layer. The porous layer also demonstrates sufficient conductivity as determined through calculations and serves as an effective method for thermal dispersion. Under optical pumping, all microdisks exhibit clear whispering gallery mode (WGM) lasing at room temperature, with the lowest threshold of 13.50 μJ/cm2 achieved in a 2-μm-diameter microdisk. These findings suggest that integrating the single porous layer into GaN microdisks is a highly promising approach for achieving high-efficiency WGM micro-laser diodes with effective electrical injection and heat dispersion.

Generating broadband cylindrical vector modes based on polarization-dependent acoustically induced fiber gratings using the dispersion turning point

Cylindrical vector beams (CVBs) with special polarization distribution have been extensively investigated due to the unique ways of interacting with matter. Although several configurations have been developed to generate CVBs, such as Q-plates and subwavelength gratings, the bandwidth of a single CVB is inherently narrow due to the phase geometry, which would limit its application for femtosecond lasers. Here, a broadband CVB mode converter based on an acoustically induced fiber grating (AIFG) and a tuning method of dispersion turning point (DTP) is demonstrated both theoretically and experimentally with the 3-dB bandwidth of 125 nm, which is more than 10 times that of conventional AIFGs. Not only can the DTP wavelength be tuned from the original 1500 nm to 1650 nm by thinning the fiber, but also the stable generation of a single broadband HE21odd/even mode can be controllably implemented by adjusting the polarization state of the incident light, owing to the larger beat length difference between HE21 and other CV modes. Additionally, the femtosecond CVBs and orbital angular momentum (OAM) modes are successfully generated and amplified by combining the broadband AIFG with a figure-9 mode-locked fiber laser. Meanwhile, it is verified by simulation that the choice of broadband CV mode and the tunability of DTP wavelength can be realized by designing ring-core fibers with different structures, which can furthermore improve the flexibility of generating high purity CVBs. This study provides a highly controllable technique for the generation of broadband CVBs and OAMs paving the way for high-capacity CVBs communication.

Low-energy micron dispersion of entangled polymers based on phase inversion composition of emulsion

This article aims to propose a low-energy method for micron dispersion of entangled polymers. We chose Ethylene-Propylene-Diene Monomer (EPDM) as the entangled polymer and acrylic esters as the dispersants to prepare the organic dispersion of the entangled polymer based on the theory that in-situ polymerization of acrylic esters had the higher solubility parameter than the original monomer. The dispersion process of entangled polymer was similar to the phase inversion of emulsion due to the maximum viscosity and minimum interfacial tension at the point of dispersion. Specifically, the average diameter of the dispersed entangled polymer was 5–6 μm. The system could still maintain excellent dispersion stability without additional dispersants. Rheology characterized that the introduction of aliphatic isocyanate derivatives reacting with hydroxyl groups in the polyacrylate to form the cross-linked skeleton could enhance the stability of the system. Excitingly, this organic dispersion allowed flexible printed circuit to fold at any angle and direction when used as the coating, and the coating still maintained excellent dispersibility, flexibility, insulation, and adhesion after aging tests. This low-energy method for micron dispersion of entangled polymers could expand their applications in coatings and other fields while maintaining their own characteristics.

Development of dispersive solid phase extraction method for the preconcentration of parathion ethyl as a simulant of nerve agent sarin from soil, plant and water samples prior to GC-MS determination.

In the presented study, an efficient and fast analytical method was developed for the determination of parathion ethyl as sarin simulant by gas chromatography-mass spectrometry (GC-MS). Dispersive solid phase extraction (DSPE) was performed to concentrate parathion ethyl from soil, plant and water samples. Reduced graphene oxide-iron (II, III) oxide (rGO-Fe3O4) nanocomposite was used as an adsorbent to collect the target analyte from the aqueous sample solutions. After the optimization of extraction/preconcentration parameters, optimum conditions for adsorbent amount, eluent type, mixing type/period, eluent volume and initial sample volume were determined as 15mg, acetonitrile, vortex/30s, 100 µL and 10mL, respectively. Under the optimum conditions, analytical performance of the developed DSPE-GC-MS method was evaluated in terms of limit of detection (LOD), limit of quantitation (LOQ) and dynamic range. Dynamic range, LOD and LOQ values were figured out to be 0.94-235.15µg/kg, 0.41µg/kg and 1.36µg/kg (mass based), respectively. Satisfactory percent recovery results (90.3-125% for soil, 93.5-108.7% for plant, 88.5-112.9% for tap water) were achieved for soil, plant and tap water samples which proved the accuracy and applicability of the developed method. It is predicted that the DSPE-GC-MS method can be accurately used for the detection of sarin in soil, plant and water samples taken from war territories.

Impacts of graphene nanoribbon dispersion and stability on the mechanical and hydration properties of cement paste: Insights from surfactant-assisted ultrasonication

In this study, we aim to evaluate the different dispersion methods that affect the dispersion behavior of graphene nanoribbons (GNRs) and to conduct a contrastive analysis of the different surfactants that influence the dispersion and stability of GNRs in deionized (DI) water and alkaline solution. Moreover, we studied uniformly dispersed GNRs with respect to the hydration, mechanical properties, and microstructure of the cement paste. Owing to the surface defects of the GNRs, electrostatic repulsion was sufficient to overcome the van der Waals force and provide a long-term period of high stability. The results show that by using SPs and 60 min of ultrasonication, the dispersibility of GNRs improved by 8.5 % and 25.7 % in DI water and alkaline solution, respectively. Uniformly dispersed GNRs accelerate the hydration and C-S-H polymerization, resulting in significant increases in compressive strength and splitting tensile strength by 17 % and 33 %, respectively, and reduced porosity by 14.6 % after 28 days of curing.

β-Caryophyllene wrapped by nanoliposomes efficiently increases the control effect on Bemisia tabaci MED

Bemisia tabaci poses a severe threat to plants, and the control of B. tabaci mainly relies on pesticides, which causes more and more rapidly increasing resistance. β-Caryophyllene is a promising ingredient for agricultural pest control, but its feature of poor water solubility need to be improved in practical applications. Nanotechnology can enhance the effectiveness and dispersion of volatile organic compounds (VOCs). In this study, a nanoliposome carrier was constructed by ethanol injection and ultrasonic dispersion method, and β-caryophyllene was wrapped inside it, thus solving the defect of poor solubility of β-caryophyllene. The size of the β-caryophyllene nanoliposomes (C-BT-NPs) was around 200 nm, with the absolute value of the zeta potential exceeding 30 mV and a PDI below 0.5. The stability was also maintained over a 14-d storage period. C-BT-NPs showed effective insecticidal activity against B. tabaci, with an LC50 of 1.51 g/L, outperforming thiamethoxam and offering efficient agricultural pest control. Furthermore, C-BT-NPs had minimal short-term impact on the growth of tomato plants, indicating that they are safety on plants. Therefore, the VOCs using nanoliposome preparation technology show promise in reducing reliance on conventional pesticides and present new approaches to managing agricultural pests.

Lab-made automated parallel-dispersive pipette extraction device for the determination of polycyclic aromatic hydrocarbons in distilled beverages (sugarcane spirits) using HPLC-DAD

This work describes the development of a new automated parallel dispersive tip microextraction method (Au-Pa-DPX) for the determination of eleven polycyclic aromatic hydrocarbons (PAHs) in four samples of Brazilian sugarcane spirit beverages, with separation and detection done by the HPLC-DAD. The results obtained with the Au-Pa-DPX approach were also compared with those obtained via the conventional parallel manual DPX method with the same samples and optimized extraction process. Desorption solvent and cycles of desorption, cleaning and extraction were optimized using response surface methodology and univariate approaches. For the Au-Pa-DPX method, the coefficient of determination (R2) ranged from 0.9948 to 0.9997. The limits of detection and quantification were all 0.303 μg l-1 and 1.00 μg l-1, respectively. Interday and intraday precision ranged from 7.6 % to 31.7 % and 0.40 % to 15.8 %, respectively. For the manual parallel DPX method, the interday and intraday precision ranged from 8.2 % to 38.1 % and 5.40 % to 18.7 %, respectively. The relative recovery values obtained with the proposed method ranged from 53.29 to 124.94 %. The enrichment factors ranged from 15.13 to 22.35. The sum of PAH concentrations in the four samples ranged from undetected to 25.58 μg l-1. These results, when correlated to other methods, highlight the gains in regards to precision obtained with the automated apparatus. Furthermore, when compared to other methods from the literature, it is an interesting green alternative for the determination of these analytes and this sample, with high throughput (4.67 min per sample), low consumption of solvents and samples, generating less waste and reducing health risks to the analyst.

Fabrication and characterization of TPGS-modified chlorogenic acid liposomes and its bioavailability in rats.

Chlorogenic acid (CGA), a polyphenol compound, exhibits excellent anti-oxidative, anti-hypoxic, antibacterial, antiviral, and anti-inflammatory activities, however the bioactivity of it has not been fully utilized in vivo due to its instability and low bioavailability. To address these issues, we prepared and characterized CGA-TPGS-LP, which is a TPGS-modified liposome loaded with CGA. The pharmacokinetics of CGA-TPGS-LP were studied in rats after oral administration. CGA-TPGS-LP was fabricated using a combination of thin film dispersion and ion-driven methods. The liposomes were observed to be uniformly small and spherical in shape. Their membranes were composed of lecithin, cholesterol, and TPGS lipophilic head with a TPGS hydrophilic tail chain coating on its surface. The loading efficiency and encapsulation efficiency were found to be 11.21% and 83.22%, respectively. The physicochemical characterisation demonstrated that the CGA was present in an amorphous form and retained its original structural state within the liposomal formulation. The stability of CGA was significantly improved by fabricating TPGS-LP. CGA-TPGS-LP exhibited good sustained-release properties in both simulated gastric and intestinal fluids. Following oral administration, ten metabolites were identified in rat plasma using UPLC-QTOF-MS. UPLC-QqQ-MS/MS quantitative analysis demonstrated that the oral bioavailability of CGA encapsulated in TPGS-modified liposomes was enhanced by 1.52 times. In addition, the three main metabolites of CGA had higher plasma concentrations and slower degradation rate. These results demonstrate that TPGS-modified liposomes could be a feasible strategy to further enhance the oral bioavailability of CGA, facilitating its clinical use.

Applicability of the inverse dispersion method to measure emissions from animal housings

Abstract. Emissions from agricultural sources substantially contribute to global warming. The inverse dispersion method (IDM) has been successfully used for emission measurements from various agricultural sources. The IDM has also been validated in multiple studies with artificial gas releases mostly in open fields. Release experiments from buildings have rarely been conducted and were partly affected by additional nearby sources of the target gas. Specific release studies for naturally ventilated animal housings are lacking. In this study, a known and predefined amount of methane (CH4) was released from an artificial source inside a barn that mimicked a naturally ventilated dairy housing, and IDM recovery rates, using a backward Lagrangian stochastic (bLS) model, were determined. For concentration measurements, open-path devices (OPs) with a path length of 110 m were placed in a downwind direction of the barn at fetches of 2.0h, 5.3h, 8.6h, and 12h (h equals the height of the highest obstacle), and a 3D ultrasonic anemometer (UA) was placed in the middle of the first three OP paths. Upwind of the barn, an additional OP and a UA were installed. The median IDM recovery rates determined with the UA placed upwind of the barn and the downwind OP ranged between 0.55–0.75. It is concluded that, for the present study case, the effect of the building and a tree in the main wind axis led to a systematic underestimation of the IDM-derived emission rate probably due to deviations in the wind field and turbulent dispersion from the underlying assumptions of the used dispersion model.