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The main objective of this work was to analyze the transport by diffusion of salts containing some metal ions (that is, CoCl2, CrCl3, HgCl2, and PbCl2), at 25.0 °C, in two different aqueous solutions with varying pH levels, namely, sodium chloride and hydrochloric chloride, by using Nernst–Hartley model equations. To analyze the applicability of this model, experimental data for two aqueous systems (CoCl2 + NaCl) and (CoCl2 + HCl), were obtained by using the Taylor technique and compared with the predicted values. The Nernst–Hartley model equations were used in this study to estimate the mutual diffusion coefficients of the eight ternary systems, which included (CoCl2 + NaCl), (HgCl2 + NaCl), (PbCl2 + NaCl), (CrCl3 + NaCl), and (CoCl2 + HCl), (HgCl2 + HCl), (PbCl2 + HCl), and (CrCl3 + HCl). By using the limiting equations of Nernst–Hartley coefficients, we were able to understand the composition dependence of the mutual diffusion coefficients of these mixed electrolyte solutions and the electrostatic mechanism for the strongly coupled diffusion of these components. [ABSTRACT FROM AUTHOR]

The clean and efficient utilization of coal is a promising way to achieve carbon neutrality. Coking coal is a scarce resource and an important raw material in the steel industry. However, the presence of pyrite sulfur affects its clean utilization. Nonetheless, this pyrite could be removed using depressants during flotation. Commonly used organic depressants (sodium lignosulfonate (SL), calcium lignosulfonate (CL), and pyrogallol (PY)) and inorganic depressants (calcium oxide (CaO) and calcium hypochlorite (Ca(ClO)2)) were chosen in this study. Their inhibition mechanism was discussed using FTIR, XPS, and molecular dynamics (MD) methods. The desulfurization ability of organic depressants was shown to be better than inorganic ones. Among the organic depressants, PY proved to be advantageous in terms of low dosage. Physical adsorption was identified as the main interaction form of SL, CL, and PY onto the surface of pyrite, as evidenced from FTIR and XPS analyses. Similarly, MD simulation results showed that hydrogen bonds played a proactive role in the interactions between PY and pyrite. The diffusion coefficient of water molecules on the pyrite surface was also observed to decrease when organic depressants were present, indicating an increase in the hydrophilicity of pyrite. This research is of great significance to utilize sulfur-containing coal and minerals. [ABSTRACT FROM AUTHOR]

In this paper, delayed stochastic integral equations with an initial condition and a drift coefficient given as interval-valued mappings are considered. These equations have a certain symmetric form that distinguishes them from classical single-valued stochastic integral equations and has implications for the properties of the diameter of the values of the solutions of the equations. The main result of the paper is the theorem that there is a unique solution to the equation considered. It was obtained under the assumptions of continuity of the kernels and Lipschitz continuity of the drift and diffusion coefficients. The proof of the existence of the solution is carried out by the method of iterating successive approximations. The paper ends with theorems about the continuous dependence of the solution on the initial function, kernels and nonlinearities. [ABSTRACT FROM AUTHOR]

Objective: Assess ADC values in prostate cancer and correlate with Gleason score. Materials and Methods: The study was done in the Department of Radiodiagnosis and Imaging, GMC Srinagar over a period of 18 months with sample size of 30, after ethical clearance from the institutional ethical committee. Results: Our study showed that mean ADC value of tumors with Gleason's score<6 was significantly different from the tumors with Gleason's score =7 and Gleason's score >7. The difference in mean ADC value of tumors with Gleason's score=7 and Gleason's score>7 were also statistically significant. Conclusion: Mean ADC values can differentiate between low risk, intermediate risk and high risk tumors. An inverse relationship between ADC values and aggressiveness of tumors with reference to biopsy Gleason score holds true. [ABSTRACT FROM AUTHOR]

The Young's modulus degradation of a biodegradable composite based on the exposure time to phosphate-buffered saline (PBS) solution was simulated by estimating the material's effective diffusion coefficient. The relationship between PBS uptake rate and material removal was investigated by comparing the finite element analysis and experimental results, and a criterion for the material removal of finite elements was proposed for an accurate material degradation simulation. The diffusion coefficient was calibrated to determine the best fit for the PBS uptake rate based on exposure time. The degradation behavior of a bone plate made of a fully biodegradable composite was analyzed using a calibrated diffusion coefficient; it was found that the screw hole parts were severely damaged owing to PBS uptake, which induced premature structural failure. To address this drawback, a hybrid bone plate composed of a nondegradable composite and a Mg wire/Polylactic acid (PLA) composite was introduced; its serviceability was verified using finite element analysis. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a sliding‐mode‐based adaptive boundary control law for stabilizing a class of uncertain diffusion processes affected by a matched disturbance. The matched disturbance is assumed to be uniformly bounded along with its time derivative, whereas the corresponding upper bounding constants are not known. This motivates the use of adaptive control strategies. In addition, the spatially‐varying diffusion coefficient is also uncertain. To achieve asymptotic stability of the plant origin in the L2$$ {L}_2 $$‐sense in the presence of the disturbance, a discontinuous boundary feedback law is proposed where the gain of the discontinuous control term is adjusted according to a gradient‐based adaptation law. A constructive Lyapunov analysis supports the stability properties of the considered closed‐loop system, yielding sufficient convergence conditions in terms of suitable inequalities involving the controllers' tuning parameters. Simulation results are presented to corroborate the theoretical findings. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical application of zonally magnified oblique multislice (ZOOM) imaging technology in patients with degenerative cervical myelopathy (DCM) and compare it with T2WI imaging. Methods: A total of 111 patients diagnosed with DCM were recruited. According to mJOA, patients with DCM were divided into ND + group with neurological dysfunction and ND- group without neurological dysfunction. Routine MRI and ZOOM-DWI were performed on 3.0 T MRI to obtain sagittal T2WI and apparent diffusion coefficient (ADC) diagram. ADC values of the narrow segment and its adjacent upper and lower segments were measured, and compared between the ND + and ND- groups. The correlation between ADC value of cervical spinal cord and mJOA score was analyzed. Additionally, ROC curves were plotted to calculate the AUC values. Results: The comparison between ND + and ND– groups shows that there are significant differences in mJOA score, T2WI, anteroposterior diameter of spinal canal, ADC values of narrow, upper and lower segment (P < 0.05). In ND + group, there is a significant difference between ADC values of the narrow and its upper and lower segments (P < 0.001), while with no significant difference in ADC values of the upper and lower segments (P > 0.05). Results of correlation analysis indicate that in the ND + group, neurological dysfunction evaluated by mJOA scores is correlated with increased ADC values of the narrow segment (r = –0.52, P < 0.001), but not significantly correlated with ADC values of the upper and lower segments. Furthermore, T2WI, anteroposterior diameter of the spinal canal, and cervical cord ADC values all has diagnostic efficacy in evaluating neurological dysfunction in DCM (AUC > 0.5, P < 0.05), with the ADC value of the narrow segment being optimal. Conclusion: The ADC value of spinal cord obtained by small-field ZOOM-DWI can be used to evaluate neurological dysfunction in DCM, and is superior to traditional T2WI. [ABSTRACT FROM AUTHOR]

Pack boriding with CeO2 was performed on the powder metallurgical (PM) near-α type titanium alloy at a temperature of 1273–1373 K for 5–15 h followed by air cooling. The microstructure analysis showed that the boride layer on the surface of the alloy was mainly composed of a monolithic TiB2 outer layer, inner whisker TiB and sub-micron sized flake-like TiB layer. The growth kinetics of the TiB2 and TiB layers obeyed the parabolic diffusion model. The diffusion coefficient of boron in the boride layers obtained in the present study was well within the ranges reported in the literature. The activation energies of boron in the TiB2 and TiB layers during the pack boriding were estimated to be 166.4 kJ/mol and 122.8 kJ/mol, respectively. Friction tests showed that alloys borided at moderate temperatures and times had lower friction coefficients, which may have been due to the fine grain strengthening effect of TiB whiskers. The alloy borided at 1273 K for 10 h had a minimum friction coefficient of 0.73. [ABSTRACT FROM AUTHOR]

Concrete with good mechanical properties and durability has always been a necessity in engineering. The addition of fibers and supplementary cementitious materials to concrete can enhance its mechanical and durability performance through a series of chemical and physical interactions. This study aims to investigate the effects of key parameters on the compressive strength, splitting tensile strength, and chloride penetration resistance of concrete combined with ground granulate blast furnace slag (GGBS) and macro polypropylene synthetic fiber (MSF). Based on the Taguchi method, a total of eighteen mixtures were evaluated, considering the effects of GGBS content, MSF content, water-to-binder (w/b) ratio, and chloride solution concentration on concrete properties. The results showed that the w/b ratio has a significant impact on the properties of concrete, which are enhanced by a decrease in w/b ratio. The GGBS content had little effect on the 28-day strength of concrete, which even decreased with a large GGBS content, but GGBS had a positive effect on the long-term strength of concrete. Moreover, the chloride penetration resistance of concrete was enhanced by an increase in the GGBS content. The MSF content had no obvious effects on the compressive strength and chloride penetration resistance of concrete, but it could enhance the splitting tensile strength to some extent, and this enhancement was more obvious over time. The chloride diffusion coefficient of concrete changed with the concentration of chloride solution, and the two increased simultaneously. [ABSTRACT FROM AUTHOR]

Solid‐state proton conductors with high conductivity at intermediate temperatures (100–300 °C) have recently gained attention due to their potential for a wide range of new electrochemical applications. The proton conductivity of cesium hydroxide hydrate (CsOH.H2O) is reported on, a superprotonic conductor whose ionic conductivity is hitherto unreported. Via a thermal treatment, the hexagonal and tetragonal CsOH.H2O phases are prepared and the effect of the degree of hydration (H2O content) on the structure and proton conductivity is investigated. It is shown that the temperature in the thermal treatment has an enormous influence on the structure and water content, and consequently, the proton transport. The conductivity of the hexagonal and tetragonal phases exceeds 3 × 103 S cm−1 at 30 °C and 10−2 S cm−1 at 120 °C, making them potentially suitable for both low‐ and intermediate‐temperature electrochemical applications. 1H NMR spin‐lattice relaxation rate measurements reveal fast dynamic processes with rates reaching the GHz regime, resulting in diffusion coefficients as high as 1.3 × 10−11 m2 s−1 at 60 °C, in good agreement with the proton conductivity results derived from impedance spectroscopy. These findings will inspire the development of novel inorganic solid proton conductors based on hydroxide hydrates. [ABSTRACT FROM AUTHOR]

We discuss the application of the three-laser optical digital interferometry method for the determination of transport properties such as the thermodiffusion, the molecular diffusion and the Soret coefficients by the thermogravitational column technique. The primary objective of this study is to illustrate the capabilities and limitations of the method for quantifying these properties in both binary and ternary liquid mixtures from an optical viewpoint. It is concluded that the system is highly robust for the analysis of binary mixtures, with the combination of the results obtained by the three wavelengths increasing the accuracy of the measurement. The study of ternary mixtures, on the contrary, is limited to certain types of conditions. While the accuracy of a three-laser interferometer can be improved, the method may be compromised if the optical contrast factor matrices are poorly conditioned. [ABSTRACT FROM AUTHOR]

We present the results of experimental study on measuring the thermodiffusion, molecular diffusion and Soret coefficients of polystyrene (4,880 g/mol) in the pure solvents toluene and cyclohexane at 298 K and atmospheric pressure. The experiments have been carried out for a wide range of concentrations, starting from the diluted state with 2 % polystyrene mass fraction (proposed in the DCMIX4 project) up to the semidilute regime of 20 % polystyrene mass fraction. In addition, we present a complete characterisation of the thermophysical properties of the analysed mixtures. Thermodiffusion, molecular diffusion and Soret coefficients of binary polymeric samples have been measured by combining the traditional thermogravitational column technique, the thermogravitational microcolumn and the optical beam deflection method. In toluene, the obtained experimental results are consistent with literature, showing that the magnitude of the mass transport thermoproperties decrease significantly with increasing polystyrene concentration, which is a first indication of an approaching glass transition in the concentrated regime. The results for thermodiffusion and molecular diffusion coefficients in cyclohexane as a function of concentration exhibit a similar trend. Nevertheless, the Soret coefficient seems to show an opposite tendency for the two solvents, increasing in magnitude for cyclohexane, at least up to the analysed polystyrene concentration. [ABSTRACT FROM AUTHOR]

Focusing on promoting the widespread application of crystal self-healing technology in marine concrete engineering and improving the durability of marine concrete, the research on the chloride ion transport behavior and corrosion resistance of concrete with crystal admixtures under the action of seawater is conducted. Ion chelator (CA) as crystalline admixture can obviously improve self-healing of cement-based materials. Results showed that CA improved pore structure of mortar, increased the compactness of matrix, and thus limited the chloride diffusion. After 3 months of erosion by NaCl + Na2SO4, NaCl + MgCl2 and NaCl + MgCl2 + Na2SO4 solutions, compared with control sample, the chloride diffusion coefficient of 100%OPC mortar with CA decreased by 49.3%, 47.4%, 56.5%, and 52.9%, respectively. CA-enhanced chloride binding ability of 100%OPC and 50%BFS mortar. Compared with control sample, the chloride binding efficiency of 100%OPC mortar with CA and 50%BFS mortar with CA increased by 26.1% and 35.5% after 3 months of NaCl solution corrosion, increased by 35.3% and 48.0% after 3 months of NaCl + Na2SO4 solution corrosion, and increased by 46.2% and 61.9% after 3 months of NaCl + MgCl2 solution corrosion, respectively. SEM analysis showed that CA could significantly improve internal microstructure of mortar under salts erosion. The correlation analysis of pore structure and chloride diffusion coefficient displayed that total porosity of mortar had better correlation with chloride diffusion coefficient than gel pore, transition pore, capillary pore and macropore after salt erosion. Therefore, CA mainly limited chloride diffusion into matrix by reducing total porosity of mortar under salt erosion. The research results of this paper can provide theoretical support and basis for the application of crystal self-healing technology in marine concrete. [ABSTRACT FROM AUTHOR]

Purpose: To assess the radiological features and clinical outcomes of odontogenic orbital cellulitis. Method: Multi-centre retrospective study of odontogenic orbital cellulitis. Primary outcomes assessed were causal organism(s), clinical signs, radiological findings, management and visual outcomes. Results: Four patients with odontogenic orbital cellulitis were identified for inclusion. There was an equal proportion of men and women with a mean age of 43 years (range 25–56 years). All patients presented with an orbital compartment syndrome, with visual acuity of counting fingers (n = 1, 25%), hand movements (n = 1, 25%) and no perception of light (n = 2, 50%). The organisms implicated were Streptococcus milleri (n = 3, 75%) and Streptococcus constellatus (n = 1, 25%). MRI findings showed a subperiosteal abscess was present in all cases, which was characterised radiologically as a T1-hyperintense, T2 minimally hyperintense collection with restricted diffusion and a low apparent diffusion coefficient signal. Final visual acuity ranged from 6/6 to no light perception. One patient required an orbital exenteration due to extensive necrosis with sepsis and systemic deterioration. Conclusions: Odontogenic orbital cellulitis carries a serious risk of vision loss with a propensity to present with an orbital compartment syndrome secondary to Streptococcus species. Outcomes were highly variable, with two cases progressing to blindness of which one required an orbital exenteration. [ABSTRACT FROM AUTHOR]

This paper studies the stochastic time-fractional heat diffusion equation involving a Caputo derivative in time of order α ∈ (1 2 , 1 ] , driven simultaneously by a random diffusion coefficient field and fractionally integrated multiplicative noise. First, the well-posedness of the underlying problem is established by proving the existence, uniqueness, and stability of the mild solution. Then a spatio-temporal discretization method based on a Milstein exponential integrator scheme and finite element method is constructed and analyzed. The strong convergence rate of the fully discrete solution is derived. Numerical experiments are finally reported to confirm the theoretical result. [ABSTRACT FROM AUTHOR]

Given global Lipschitz continuity and differentiability of high enough order on the coefficients in Itô's equation, differentiability of associated semigroups, existence of twice differentiable solutions to Kolmogorov equations and weak convergence rates of order one for numerical approximations are known. In this work and against the counterexamples of Hairer et al. (Ann Probab 43(2):468–527, https://doi.org/10.1214/13-AOP838, 2015), the drift and diffusion coefficients having Lipschitz constants that are o (log V) and o (log V) respectively for a function V satisfying (∂ t + L) V ≤ C V is shown to be a generalizing condition in place of global Lipschitz continuity for the above. [ABSTRACT FROM AUTHOR]

This study identified the distinct magnetic resonance imaging findings of cervical gastric–type adenocarcinoma (GAS) that can help differentiate it from squamous cell carcinoma (SCC) and usual-type endocervical adenocarcinoma (UEA) and reveal the radiologic–pathologic correlation. All consecutive patients with cervical GAS treated at our hospital from November 2009 to August 2021 were included. The SCC and UEA cases were considered controls. Tumor location, tumor shape, presence and size of cysts, presence of uterine fluid, and apparent diffusion coefficient (ADC) were evaluated. Overall, 18 GAS, 55 SCC, and 23 UEA cases were evaluated. The tumor was located in the entire cervix in 13/18 GAS cases, whereas it was predominantly located in the lower cervix in 38/55 SCC cases and 14/23 UEA cases. Most GAS cases exhibited a diffuse infiltration growth pattern (17/18), whereas most SCC and UEA cases exhibited a mass-forming pattern (39/55 and 20/23, respectively). Moreover, the percentages of cases presenting microcysts or macrocysts and undergoing uterine fluid collection were significantly higher in the GAS group (14/18 and 13/18) than in the SCC and UEA groups. ADC was significantly higher in the GAS group than in the SCC group (1.092 × 10−3 vs. 0.819 × 10−3 mm2/s). This study revealed that GAS is characterized by tumor presence in the entire cervix, infiltrative growth pattern, intrauterine fluid collection, and frequent microcyst or macrocyst formation. Moreover, ADC was significantly higher in the GAS group than in the SCC group. • Image characteristics of cervical gastric-type adenocarcinoma • Lesion involvement of the entire cervix. • Diffuse growth pattern. • Intrauterine fluid collection. • Frequent cyst formation. • High ADC values compared to SCC. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate a new motion correction method, named RT + NV Track, for upper abdominal DWI that combines the respiratory triggering (RT) method using a respiration sensor and the Navigator Track (NV Track) method using navigator echoes. Materials and methods: To evaluate image quality acquired upper abdominal DWI and ADC images with RT, NV, and RT + NV Track in 10 healthy volunteers and 35 patients, signal-to-noise efficiency (SNRefficiency) and the coefficient of variation (CV) of ADC values were measured. Five radiologists independently performed qualitative image-analysis assessments. Results: RT + NV Track showed significantly higher SNRefficiency than RT and NV (14.01 ± 4.86 vs 12.05 ± 4.65, 10.05 ± 3.18; p < 0.001, p < 0.001). RT + NV Track was superior to RT and equal or better quality than NV in CV and visual evaluation of ADC values (0.033 ± 0.018 vs 0.080 ± 0.042, 0.057 ± 0.034; p < 0.001, p < 0.001). RT + NV Track tends to acquire only expiratory data rather than NV, even in patients with relatively rapid breathing, and can correct for respiratory depth variations, a weakness of RT, thus minimizing image quality degradation. Conclusion: The RT + NV Track method is an efficient imaging method that combines the advantages of both RT and NV methods in upper abdominal DWI, providing stably good images in a short scan time. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the drying kinetics of fruit and vegetable peel biowaste using a sustainable technique as a key-pretreatment for its conversion into useful feedstock. Biowaste represents a missed potential source of bioenergy and bioproducts, but moisture removal is required, and conventional drying methods are expensive since they require great quantity of energy supplied, almost always, by a non-renewable energy. In this study six batches with the same quantity of biowaste, and heterogeneous physical composition were dried under open-sun conditions. We evaluated the influence of the interaction between drying area and the initial moisture content on drying rate. Eight semi-theoretical models were fitted using Levenberg–Marquardt algorithm to predict drying rate, and their accuracy was assessed through goodness-of-fit tests. Maximum moisture content to preserve biomass (10%) was reached on 5th day and the equilibrium on 16th day of drying. According to goodness-of-fit test (R2 = 0.999, χ2 = 4.666 × 10−5, RMSE = 0.00683) the best model to predict drying rate was Two-term model. The mathematical model obtained from Fick's second law is reliable to predict drying kinetics, R2 (0.9648 ± 0.0106); despite the variation between drying area and initial moisture content. Kruskal-Wallis test showed that drying rates between batches are not significantly different (p = 0.639; 0.05); nor effective diffusion coefficient (Deff = 4.97 × 10−11 ± 0.3491 × 10−11), (p = 0.723; 0.05). The study of drying kinetics is crucial for selecting the optimal biowaste treatment based on its generation context. This could enable its use as feedstock for bioproduct or bioenergy production, thereby reducing waste accumulation in landfills and environmental impact. [ABSTRACT FROM AUTHOR]

Purpose: Prostate tissue has a complex microstructure, mainly composed of epithelial and stromal cells, and of extracellular (acinar‐luminal) spaces. Diffusion‐weighted MR spectroscopy (DW‐MRS) is ideally suited to explore complex microstructure in vivo with metabolites selectively distributed in different subspaces. To date, this technique has been applied to brain and muscle. This study presents the development and pioneering utilization of 1H‐DW‐MRS in the prostate, accompanied by in vitro studies to support interpretations of in vivo findings. Methods: Nine healthy volunteers underwent a prostate MR examination (mean age, 56 years; range, 31–66). Metabolic complexation was studied in vitro using solutions with major compounds found in prostatic fluid of the lumen. DW‐MRS was performed at 3 T with a non–water‐suppressed single‐voxel sequence with metabolite‐cycling to concurrently measure metabolite and water signals. The water signal was used in postprocessing as a reference in a motion‐compensation scheme. The spectra were fitted simultaneously in the spectral and diffusion‐weighting dimensions. Apparent diffusion coefficients (ADCs) were derived by fitting signal decays that were assumed to be mono‐exponential for metabolites and biexponential for water. Results: DW‐MRS of the prostate revealed relatively low ADCs for Cho and Cr compounds, aligning with their intracellular location and higher ADCs for citrate and spermine supporting their luminal origin. In vitro assessments of the ADCs of citrate and spermine demonstrated their complex formation and protein binding. Tissue concentrations of MRS‐detectable metabolites were as expected for the voxel location. Conclusions: This work successfully demonstrates the feasibility of 1H‐DW‐MRS of the prostate and its potential for providing valuable microstructural information. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate the principal spectral theory and asymptotic behavior of the spectral bound for cooperative nonlocal dispersal systems, specifically focusing on the case where partial diffusion coefficients are zero, referred to as the partially degenerate case. We propose two sufficient conditions that ensure the existence of the principal eigenvalue in these partially degenerate systems. Additionally, we study the asymptotic behavior of the spectral bound for nonlocal dispersal operators with small and large diffusion coefficients, considering both non-degenerate and partially degenerate cases. Notably, we find a threshold-type result as the diffusion coefficients tend towards infinity in the partially degenerate case. Finally, we apply these findings to discuss the asymptotic behavior of the basic reproduction ratio in a viral diffusion model. [ABSTRACT FROM AUTHOR]

Due to the excellent quantum conversion and spectral response characteristics of the AlGaN photocathode, it has become the most promising III-V group semiconductor photocathode in solar-blind signal photoconversion devices in the ultraviolet band. Herein, the influence factors of the time-resolved characteristics of the AlGaN photocathode are researched by solving the photoelectron continuity equation and photoelectron flow density equation, such as the AlN/AlGaN interface recombination rate, AlGaN electron diffusion coefficient, and AlGaN activation layer thickness. The results show that the response time of the AlGaN photocathode decreases gradually with the increase in AlGaN photoelectron diffusion coefficient and AlN/AlGaN interface recombination rate, but the response time of the AlGaN photocathode gradually becomes saturated with the further increase in AlN/AlGaN interface recombination rate. When the thickness of the AlGaN photocathode is reduced from 250 nm to 50 nm, the response time of the AlGaN photocathode decreases from 63.28 ps to 9.91 ps, and the response time of AlGaN photocathode greatly improves. This study provides theoretical guidance for the development of a fast response UV detector. [ABSTRACT FROM AUTHOR]

This article was based on indoor simulated marine environment erosion tests using concrete, by analyzing the compressive strength, coating bonding strength and chloride ion diffusion behavior of marine cast-in-place concrete after erosion, and the effects of anti-corrosion coating / treating ages on the mechanical properties and durability evolution of marine cast-in-place concrete were studied. The results show that compared with concrete without anti-corrosion coating / treating, anti-corrosion coating / treating concrete using silane and polyurethane coating shows a decrease in compressive strength fc after erosion in marine tidal areas, and concrete fc gradually decreases with the increase of curing age tc . Anti-corrosion coating / treating can effectively improve the long-term chloride ion erosion resistance of marine cast-in-place concrete, and with the increase of curing age tc, the effects of anti-corrosion coating / treating on reducing the surface chloride ion content Cs and apparent chloride ion diffusion coefficient Da of concrete becomes more significant. Taking into account the development of mechanical properties of cast-in-place concrete in the marine tidal zone environment and the effectiveness of anti-corrosion coating / treating measures, it is recommended to use silane and polyurethane coatings for coating with a curing age of not less than 5 and 10 d, respectively. [ABSTRACT FROM AUTHOR]

CO2 flooding plays a significant part in enhancing oil recovery and is essential to achieving CCUS (Carbon Capture, Utilization, and Storage). This study aims to understand the fundamental theory of CO2 dissolving and diffusing into crude oil and how these processes vary under reasonable reservoir conditions. In this paper, we primarily use molecular dynamics simulation to construct a multi-component crude oil model with 17 hydrocarbons, which is on the basis of a component analysis of oil samples through laboratory experiments. Then, the CO2 dissolving capacity of the multi-component crude was quantitatively characterized and the impacts of external conditions—including temperature and pressure—on the motion of the CO2 dissolution and diffusion coefficients were systematically investigated. Finally, the swelling behavior of mixed CO2–crude oil was analyzed and the diffusion coefficients were predicted; furthermore, the levels of CO2 impacting the oil's mobility were analyzed. Results showed that temperature stimulation intensified molecular thermal motion and increased the voids between the alkane molecules, promoting the rapid dissolution and diffusion of CO2. This caused the crude oil to swell and reduced its viscosity, further improving the mobility of the crude oil. As the pressure increased, the voids between the internal and external potential energy of the crude oil models became wider, facilitating the dissolution of CO2. However, when subjected to external compression, the CO2 molecules' diffusing progress within the oil samples was significantly limited, even diverging to zero, which inhabited the improvement in oil mobility. This study provides some meaningful insights into the effect of CO2 on improving molecular-scale mobility, providing theoretical guidance for subsequent investigations into CO2–crude oil mixtures' complicated and detailed behavior. [ABSTRACT FROM AUTHOR]

In this work, the random pore model (RPM) is utilized for the kinetic study of hematite reduction to Iron with CO. This can significantly contribute to the more effective design of reduction reactors in Iron production plants. Indeed, the developed RPM in this work employs a real pore size distribution (PSD) of the solid reactant, resulting in more realistic and accurate kinetic parameters. Accordingly, the kinetic parameters were calculated via RPM using the data from the reduction experiments of a highly porous pure hematite pellet. Validation of such kinetic parameters by different pure hematite and industrial pellets with various porous structures demonstrated RPM as the most comprehensive non-catalytic gas–solid reactions model. The activation energy obtained for the mentioned reaction was calculated at 25.5 kJ/mol. In addition, oxygen ions showed a mean diffusion coefficient of 1.18 × 10−16 m2/s for the industrial pellets through the Iron product layer. Furthermore, the importance of adjusting the CO–CO2 ratio on the conversion in the reduction reactor was discussed. The results of this work could help reduce the amount of required CO and CO2 product during the reduction of hematite to Iron. [ABSTRACT FROM AUTHOR]

In response to the imperative for sustainable iron production with reduced CO2 emissions, this study delves into the intricate role of TiO2 in the direct reduction of iron oxide pellets. The TiO2-dependent reducibility of iron oxide pellets utilizing H2 and CO gas across varied temperatures and gas compositions is thoroughly investigated. Our findings unveil the nuanced nature of the TiO2 effect, underscored by its concentration-dependent behavior, revealing an optimal range between 1 and 1.5 pct TiO2, where a neutral or positive impact on reduction kinetics and diffusion coefficient is observed. Notably, the synergistic interplay of CO and H2 at 1000 °C emerges as particularly efficacious, suggesting complementary effects on the reduction process. The introduction of H2 into the reducing atmosphere regulated by CO not only extends the transition range but also markedly expedites the rate of reduction. Furthermore, our study highlights the temperature sensitivity of the TiO2 effect, with higher TiO2 content correlating with prolonged reduction time in a 100 pct H2 atmosphere at 900 °C. In a 100 pct H2 atmosphere, the non-contributory role of TiO2 stems from the water-gas shift reaction. Conversely, introducing H2 into a CO-controlled reducing atmosphere with TiO2 enhances the transition range and expedites the reduction rate. Additionally, our findings underscore the role of total iron content, revealing a direct correlation with the reduction process. [ABSTRACT FROM AUTHOR]

With increasing emphasis on low-carbon environmental protection, CO2 enhanced coalbed methane production and methane reuse in abandoned mines (rich in N2) have gradually become one of the future development directions. These scenarios involve the coordinated migration of different gases such as CO2, CH4, and N2, and the differences in properties of different gases that affect the flow process. Previous studies often focused on the adsorption differences between gases, neglecting the differences during desorption process. In view of this, the current work conducted experiments and finite element numerical analysis on the desorption process of CO2, CH4, and N2, clarified the differences and influencing factors of desorption among the gases, and analyzed the flow change rules under different permeability and diffusion capabilities. The results indicated that the main differences among CO2, CH4, and N2 during desorption are reflected in the parameters of Langmuir volume, permeability, and diffusion coefficient. These parameters showed that CO2 has the highest value during desorption, while N2 has the lowest. The factors affecting the magnitude of differences between CO2, CH4, and N2 are mainly their compositions. Specifically, ash content significantly affects the difference in adsorption capacity, while moisture content influences permeability and diffusion coefficient. During desorption, permeability plays a continuous role throughout the whole process, while diffusion coefficient is exhibited mainly in the initial stage of desorption. Different gases have varying sensitivities to permeability and diffusion coefficients during desorption. Changes in permeability and diffusion coefficient significantly affect the CO2 desorption process. N2, on the other hand, is the least sensitive, especially to changes in diffusion coefficient. During gas flow, when reservoir permeability is less than 0.01 mD (= 9.869233 × 10−18 m2), permeability becomes the main factor that affects flow. When the diffusion coefficient is less than 5 × 10−9 m2/s, increasing the diffusion coefficient is necessary to effectively promote gas outflow. To effectively increase gas production, it is necessary to comprehensively consider the magnitudes of permeability and diffusion coefficient. [ABSTRACT FROM AUTHOR]

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Ammonium dinitramide (ADN) is a new type of green energetic oxidizer with excellent energy density and low pollution combustion characteristics. However, the strong hygroscopicity has a significant impact on its practical application. To assist in the research on moisture-proof modification of ADN materials, an innovative hygroscopic modeling approach was proposed to evaluate the hygroscopicity of ADN at various temperatures and humidities. By investigating the diffusion coefficient of water molecules in molecular dynamics processes, a visual insight into the hygroscopic process of ADN was gained. Furthermore, analyzing the non-covalent interactions between ADN and water molecules, the hygroscopicity of ADN could be evaluated qualitatively and quantitatively. The energy analysis revealed that electrostatic forces play a dominant role in the process of water adsorption by ADN, whereas van der Waals forces impede it. As a whole, the simulation results show that ADN presents the following hygroscopic law: At temperatures ranging from 273 K to 373 K and relative humidity (RH) from 10% to 100%, the hygroscopicity of ADN generally shows an increasing trend with the rise in temperature and humidity based on the results of three simulations. According to the non-hygroscopic point (298 K, 52% RH) of ADN obtained by experiment in the literature, a non-hygroscopic range of temperature and humidity for ADN can be depicted when the simulation results in relative hygroscopicity is less than or equal to 17%. This study can provide effective strategies for screening anti-hygroscopic modified materials of ADN. [ABSTRACT FROM AUTHOR]

The energy of ring current protons is believed to influence the pitch angle scattering due to electromagnetic ion cyclotron (EMIC) waves and is typically analyzed using quasi‐linear theory. However, nonlinear behavior becomes significant as the wave amplitude intensifies. In this study, we aim to explore how the nonlinear behavior depends on the initial proton energy under various background plasma density conditions. The frequency of EMIC waves is 0.96ΩHe (where ΩHe is the gyrofrequency of He+ at the equator). It is found that the higher energy protons with nonlinear phase trapping experience more resonances, causing these trapped protons to move away from the loss cone more quickly compared to lower energy protons. However, the proportion of phase‐trapped protons significantly decreases as the initial proton energy increases. This declining trend is more pronounced for a background plasma condition in the plasmapause than within the plasmasphere. The number of phase‐trapped protons goes to zero as initial proton energy increases to above approximately 60 keV. Additionally, nonlinear phase bunching is more pronounced for lower energy protons (e.g., below 60 keV) compared to higher energy protons. As a result, both nonlinear phase trapping and phase bunching contribute to larger standard deviations in the net changes of equatorial pitch angle (Δαeq), suggesting a larger pitch agnel diffusion coefficient compared to the prediction of quasi‐linear theory. Key Points: The proportion of phase‐trapped protons is sensitive to changes in initial proton energy, and decreases as the initial proton energy increasesHigher energy protons with phase trapping experience more resonances, which will move quickly away from the loss coneTest‐particle pitch angle diffusion is more pronounced in lower energy protons (e.g., below 60 keV) compared to higher energy protons [ABSTRACT FROM AUTHOR]

The diffusion of o-chlorotoluene (OCT), a hydrophobic organic compound, solubilized by means of the Triton X-100 surfactant from the region of local contamination into adjacent pure layers has been experimentally studied in a model kaolin based dispersion. The study is aimed at clarifying the factors influencing the motion of impurities in a dispersion medium with and without an electrical field. The theoretical analysis of obtained experimental data makes it possible to establish the effective diffusion coefficients of formed OCT/surfactant complexes in the pore space, which demonstrate the acceleration of the spread of contamination due to the influence of an electrical field. It has been shown that the diffusion coefficients of these complexes grow due to electroosmosis and hydrodynamic flows induced by it. Electroosmosis along negatively charged kaolin particles promotes the transport of impurities towards the cathode. At the same time, local narrowing of pores with a closed experimental cell leads to the pore solution hydrodynamic flows, which transport the impurities in the direction opposite to electroosmosis. Hence, due to a complicated interparticle space configuration, the electrical field actually results in pore solution mixing, which affects the character of the diffusion flows of impurities. Mixing may also be additionally intensified due to the heterogeneous charge of kaolin particles, which causes local changes in the direction of electroosmosis. At the same time, not only the fact of mixing as such is important, but also its specific features caused by different characters of electroosmotic and hydrodynamic flows and, correspondingly, by an sharp change in the direction of liquid flow near the surface of kaolin particles. As a consequence, the desorption of OCT/surfactant complexes from the surface of particles into the pore solution should be intensified and, correspondingly, the efficiency of their removal from the disperse systems should increase. [ABSTRACT FROM AUTHOR]

The aim of this paper is to discover analytically the interactional responses of populations in a dynamic region where the reaction–diffusion process with forcing effects takes place through traveling wave solutions. An expansion method is considered here to properly capture the responses for the first time. In order to profoundly analyze the physical and mathematical discussions, some illustrative behavioral results are exhibited for various values of physical parameters. Especially for the different values of diffusion coefficients in the model under consideration, their effects on the behavior of the solitary wave are discussed and observationally supported by considering various illustrations. It is also seen that the solutions representing the diffusion seen to be in the form of the behavior of hexagonal Turing patterns in different time periods. The application of this study in mathematical biology is to analyze the relationship between the population density of certain species in any local region and the specific population density with invasion characteristics. In addition, the formation of the extinction vortex of the invading population, depending on the characteristics of the solutions presented, is also descriptively discussed. [ABSTRACT FROM AUTHOR]

We studied positive streamers with a 5 mm gap under 20–101 kPa pressure and 1%–31% O2 concentrations conditions using a 2D axisymmetric fluid model based on local field approximation. As the pressure decreases from 101 kPa to 20 kPa, the axial reduced electric field, the mean electron energy and the electron diffusion coefficient increase, which leads to the acceleration of the streamer propagation velocity and the increase of the streamer channel radius. The opposite change of ionization cross section and gas molecular density caused by the decrease of pressure leads to the non-monotonic change of the peak of net ionization rate. At medium-low pressure, there is a wider ionization region at the streamer head. As the O2 concentration decreases from 31% to 1% in N2/O2, the streamer propagation velocity decreases. When the O2 concentration drops to 1%, the streamer velocity decreases with a descent gradient of nearly 4 times, compared to 11% O2. Based on the space charge effect and chemical reaction rate, a possible mechanism is proposed to explain the abrupt change in the streamer velocity. [ABSTRACT FROM AUTHOR]

As a common smart hydrogel, thermo‐sensitive hydrogel exhibits significant potential applications in the field of biological engineering due to its unique property of undergoing a substantial volume transition in response to temperature changes. For numerical implementation of thermo‐sensitive hydrogel, many approaches have been developed to simulate the transient deformation during fluid diffusion or heat conduction process. However, the numerical approach for the transient deformation during both fluid diffusion and heat conduction processes is still lacking. To this end, we develop a three‐field coupled finite element framework that can be used to simulate the transient deformation behavior of thermo‐sensitive hydrogel involving large deformation, fluid diffusion, and heat conduction. In the proposed framework, there exist three processes that deal with displacement, concentration, and temperature fields, separately. To realize the coupling of three fields, the separated solving processes are assembled together by using a two‐way coupled approach. Based on the developed finite element framework, the coupling effects between the concentration and temperature can be realized by defining a body flux and a temperature‐dependent diffusion coefficient without solving the complex coupling equations. The finite element framework is implemented in ABAQUS by utilizing several user subroutines. The numerical implementation is validated by comparing the numerical results of a hydrogel disk with experimental results. Furthermore, various numerical examples are simulated to investigate the applicability of the proposed finite element framework under different multi‐field coupling conditions. The proposed finite element scheme is proved to be an efficient and stable tool for numerically simulating the transient behavior of thermo‐sensitive hydrogel incorporating the phase transition effect. [ABSTRACT FROM AUTHOR]

The rate of oxygen diffusion directly affects the distribution of oxygen concentration within concrete, which in turn influences the corrosion performance of reinforcing steel within the concrete. However, research on cross-scale prediction models for oxygen diffusion in dry concrete is still lacking. In this study, the complex pore structure of concrete is simplified into a sponge model, and three types of diffusion are quantitatively characterized based on the pore size distribution density function. The influence of porosity, water–cement ratio, hydration degree, gel–space ratio and pore tortuosity on the oxygen diffusion coefficient is considered, and a cross-scale prediction model for oxygen diffusion in dry concrete is established. Secondly, an oxygen diffusion coefficient determination device developed independently is used to measure the oxygen diffusion coefficient of concrete specimens under dry conditions. The results show that the experimental values agree well with the calculated values, and the model is compared with other models proposed by scholars, verifying its superiority and accuracy. Finally, a parameter sensitivity analysis is conducted on five microscale parameters and their influence on the behavior of oxygen transmission into concrete is discussed. The establishment of the cross-scale prediction model for oxygen diffusion in dry concrete will first provide a positive role in the theoretical research on reinforcement expansion and cracking, and secondly, it will be able to better explain the mechanism of oxygen diffusion in concrete. [ABSTRACT FROM AUTHOR]

Background: To investigate the values of apparent diffusion coefficient (ADC) for the treatment response evaluation in pancreatic cancer (PC) patients receiving neoadjuvant therapy (NAT). Methods: This study included 103 NAT patients with histologically proven PC. ADC maps were generated using monoexponential diffusion-weighted imaging (b values: 50, 800 s/mm2). Tumors' minimum, maximum, and mean ADCs were measured and compared pre- and post-NAT. Variations in ADC values measured between pre- and post-NAT completion for NAT methods (chemotherapy, chemoradiotherapy), tumor locations (head/neck, body/tail), tumor regression grade (TRG) levels (0–2, 3), N stages (N0, N1/N2) and tumor resection margin status (R0, R1), were further analyzed. Results: The minimum, maximum, and mean ADC values all increased dramatically after NAT, rising from 23.4 to 25.4% (all p < 0.001): mean (average: 1.626 × 10− 3 mm2/s vs. 1.315 × 10− 3 mm2/s), minimum (median: 1.274 × 10− 3 mm2/s vs. 1.034 × 10− 3 mm2/s), and maximum (average: 1.981 × 10− 3 mm2/s vs. 1.580 × 10− 3 mm2/s). The ADCs between the subgroups of all the criteria under investigation did not differ significantly for the minimum, maximum, or mean values pre- or post-NAT (P = 0.08 to 1.00). In the patients with borderline resectable PC (n = 47), the rate of tumor size changes after NAT was correlated with the pre-NAT mean ADC values (Spearman's coefficient: 0.288, P = 0.049). Conclusions: The ADC values of PC increased significantly following NAT; however, the percentage increases failed to provide any predictive value for the resection margin status or TRG levels. [ABSTRACT FROM AUTHOR]

Magnesium containing high entropy alloys have gained attention recently as a potential material for hydrogen storage applications. In this work, five non-equiatomic compositions of MgTiZrNiAl HEAs were synthesized using a high-energy ball milling technique and electrochemically characterized for hydrogen storage performance. The concentrations of Mg and other constituent alloying elements are critical to achieving good storage capacity and other hydrogen storage properties. Interestingly, higher Mg atomic percent (40–50 at%) in the HEA matrix showed high gravimetric capacity, and increasing the constituent element like Ni has significantly enhanced the overall storage capacity, kinetics, and thermodynamic properties. Overall, 1 wt% of hydrogen was electrochemically stored with high reversibility, improved hydrogen diffusion coefficient, and anticorrosion ability. [Display omitted] • Five different non-equiatomic HEA were prepared by altering Mg and Ni concentrations via high-energy ball milling. • Increasing Mg concentration in the HEA matrix has led to the formation of a multiphase structure. • Mg concentration up to 50 at% showed a high gravimetric capacity with improved kinetics properties. • Increasing Ni concentration showed an enhanced capacity, with ∼99% reversibility, and high hydrogen diffusion ratio. [ABSTRACT FROM AUTHOR]

(Zr0.8Sn0.2)TiO4 (ZST) microwave dielectric ceramic powder was synthesized by the hydrothermal-molten salt (HMS) method, and the effects of different molding methods on the physical phases, microscopic morphology, and dielectric properties of ZST ceramics were investigated. On this basis, ZST-NZ laminated composites were prepared, and the interfacial diffusion and laminated co-firing behaviors of the composites were studied more systematically. The results show that the heat-pressing process can be used to obtain high-frequency dielectric ceramics with more comprehensive performance. The dielectric properties (1 MHz) were ɛr = 40.5, tanδ = 1.32 × 10−3. ZST-NZ laminated composites have relatively tight interfacial bonding but show significant interfacial diffusion. The mutual diffusion of ZST-NZ composites follows the semi-infinite diffusion coupling model. Based on this diffusion model, the ionic concentration distribution function was established to simulate the interfacial diffusion of ions, and the diffusion coefficients and diffusion activation energies of Fe3+, Zn2+, Sn4+, and Zr4+ were calculated under different conditions. The magnitude of diffusion coefficients in the H-ZST-NZ diffusion couples was in the order of D (Fe3+) > D (Zn2+) > D (Sn4+) > D (Zr4+), and the magnitude of diffusion activation energies at 1275 °C was in the order of Qd (Zr4+) > Qd (Sn4+) > Qd (Zn2+) > Qd (Fe3+). The strong diffusion of Ti and Fe led to the decomposition of ZST and NZ ferrite, producing new TiO2 and Fe3O4 phases, which resulted in the degradation of the dielectric properties of the composites. [ABSTRACT FROM AUTHOR]

Transmissible gastroenteritis virus (TGEV) causes high mortality in young piglets (< 3 days of age). With aging, the susceptibility/morbidity/mortality rates drop. We previously hypothesized that the age-related changes in the intestinal mucus could be responsible for this resistance. Hence, this study investigated the effect of porcine intestinal mucus from 3-day and 3-week-old pigs on the free mobility of the virulent TGEV Miller strain, and on the infection in swine testicle (ST) cells. Single particle tracking (SPT) revealed that TGEV had significantly higher diffusion coefficients in 3-day mucus compared to 3-week mucus. TGEV and charged and uncharged control nanoparticles diffused freely in 3-day mucus but were hindered by 3-week mucus in the diffusion model; TGEV mimicked the diffusion behavior of negatively charged carboxylated particles. Inoculation of ST cells with TGEV in the presence of 3-week mucus resulted in a significantly lower average number of infected cells (30.9 ± 11.9/5 fields) compared with 3-day mucus (84.6 ± 16.4/5 fields). These results show that 3-week mucus has a significant TGEV-blocking activity compared to 3-day mucus in free diffusion and infection of the underlying susceptible cells. Additionally, a label-free proteomics analysis revealed an increased expression of mucin 13, known for negatively regulating the tight junctions in intestinal epithelium, in 3-day-old pigs. In 3-week-old pigs, a higher expression of mucin 2, a type of secreted mucin which is known for inhibiting coronavirus infection, was observed. Concludingly, this study demonstrated a protective effect of 3-week mucus against viral infections. [ABSTRACT FROM AUTHOR]

This study employed modified graphitic carbon nitride (g‐C3N4) nanosheets and polyether block amide (Pebax) to prepare mixed matrix membranes (MMMs) aiming to enhance CO2 separation efficiency. Through sulfonation and zinc ion (Zn2+) modification of g‐C3N4 nanosheets, high Zn2+ loaded nanofillers (SCN‐Zn2+) were synthesized. Compared to g‐C3N4, MMMs with SCN‐Zn2+ as nanofiller showed a CO2 permeance of 462 Barrer as well as the CO2/N2 selectivity of 47.5 at the feed gas pressure of 2 bar, which surpassed the 2008 Robeson upper bound. Additionally, the Pebax/SCN‐Zn2+(30) membrane was subjected to continuous gas permeability experiments for 70 h and showed good stability. The results showed that SCN‐Zn2+ nanosheets played an important role in enhancing the gas selectivity of the membranes. SEM confirmed that the SCN‐Zn2+ nanosheets had good compatibility with the Pebax substrate and the presence of hydrophilic sulfonic acid groups effectively suppressed the interfacial defects. The increase in the free volume fraction of the membranes as well as the solubility and diffusion coefficient suggested that the introduction of g‐C3N4 nanosheets led to more tortuous gas transport paths, which enhanced the permeability and selectivity of CO2. [ABSTRACT FROM AUTHOR]

To interpret the diffusion behavior of oxygen in epoxy asphalt with different cross‐linking degrees, epoxy asphalt‐oxygen diffusion layer models were constructed. The effect of temperature on oxygen diffusion and the number of oxygen molecules penetrating the epoxy asphalt was quantitatively analyzed. Fick's second law was used to determine the oxygen diffusion coefficient. The Mean square displacement (MSD) was extracted to analyze the effect of cross‐linking degree on the molecular motion of the base asphalt. The results show that as the cross‐linking degree increases, the number of oxygen in the epoxy asphalt decreases, accompanied by a reduction in the oxygen diffusion coefficient. Temperature significantly affects the rate of oxygen diffusion, with higher temperatures leading to greater diffusion depths over the same simulation time. The oxygen diffusion coefficient of epoxy asphalt ranges from 4.60 × 10−11 to 2.20 × 10−10 m2/s at temperatures of 298–373 K. The epoxy system markedly restricts the movement of base asphalt molecules, with saturate being most affected by cross‐linking degree and asphaltene the least. A high cross‐linking network impedes the asphalt‐oxygen contact oxidation, enhancing epoxy asphalt's anti‐aging capacity. These findings provide support for optimizing epoxy asphalt formulations and guiding the development of anti‐oxidant epoxy asphalt. [ABSTRACT FROM AUTHOR]

Directed transportation of materials at molecular scale is important due to its crucial role in the development of nanoelectromechanical devices, particularly the directional movements along the carbon nanotubes (CNTs), due to the applications of CNTs as nano-manipulators, confined reactors, and drug or other materials delivery systems. In the present investigation, we evaluate the movements of C60 fullerenes on the surface of the cone-shaped CNTs. The fullerene molecules indicate directed motion toward the narrower end of CNTs, which is due to the potential energy gradient along the nanotube length. A continuum model is proposed to evaluate the mechanism of the directed motion and the results of the theoretical model are compared with numerical simulations. Directed movements have been examined at various opening angles of CNTs, considering the trajectories of motions, variation of potential energy, and diffusion coefficients. At smaller opening angles, the driving force on the C60 increases and the molecule experiences more directed transport along the nanotube. The motion of fullerene has also been simulated inside the cone-shaped CNTs, with similar opening angle, and different average radius. At lower average radius of the cone-like nanotubes, the motion of C60 is comparatively more rectilinear. Directional transport of fullerene has been observed in the opposite direction, when the molecule moves on the external surface of the cone-like CNTs, which is due to the stronger interaction of C60 with the parts of the external surface with larger radius. The effect of temperature has been evaluated by performing the simulations at the temperature range of 100 to 400 K. The direction of the velocity reveals that the thermal fluctuations at higher temperatures hinder the directed motion of molecule along the cone-shaped CNTs. The results of the present study propose a new method to obtain directed transport of molecules which can be helpful in different applications such as drug delivery systems. [ABSTRACT FROM AUTHOR]

Multiple flow mechanisms that coexist in nanoscale porous media are responsible for deviations from the linear Klinkenberg equation. The use of mathematical models in the literature has obvious limitations in evaluating this flow phenomenon because the viscosity/diffusion coefficients of nanoscale porous media are more accurate only in the limited Knudsen number region. By introducing, the concept of an effective molecular mean free path, this paper proposes single models of viscosity/diffusion for the full Knudsen number range to replace the combination model in the literature. On this basis, a new apparent permeability model is developed with multiple coexisting mechanisms for the full Knudsen number range, and the effectiveness of the proposed model is verified by using published data. The discontinuous problem of the combination model of the viscosity/diffusion coefficient in the literature for the full Knudsen number range is solved using the new viscosity and diffusion coefficient models. The new apparent permeability model accurately predicts the absolute permeability and explains the phenomenon of deviation from the linear Klinkenberg equation. This paper further discusses the influence of different mechanisms on the permeability. The rarefaction effect weakens the diffusion ability in porous media but increases the contribution of Darcy flow to permeability. The viscous flow increment, absolute permeability and slippage effect were the most important flow mechanisms in nanopores. Article Highlights: We present the equation of the gas viscosity/diffusion coefficient in nanopores for the full Knudsen number range. We present a new apparent permeability model with multiple coexisting mechanisms for the full Knudsen number range. Our model predicts the absolute permeability of nanoscale porous media. [ABSTRACT FROM AUTHOR]

Coalbed methane thermodynamic extraction, as an emerging ECBM recovery method, can effectively improve gas recovery rates. And clarifying methane diffusion and migration law in coal under thermal stimulation is crucial for the selection of its process parameters. Based on laboratory methane adsorption-release experiments, the evolution law of methane diffusion characteristics with temperature and pressure was studied, and the control mechanism of heat-dependent methane diffusion behavior was explored. The results show that both thermal stimulation and high adsorption pressure accelerated the methane diffusion rate in coal. Adsorption pressure had little effect on methane diffusion percentage, but thermal stimulation promoted a significant increase in diffusion percentage and improved the net methane yield. The influence mechanisms of adsorption pressure and thermal stimulation on methane diffusion characteristics are elucidated in relation to the amount and proportion of methane-activated molecules in the diffusion process. The constant diffusion coefficient of methane is heat-dependent, based on which a diffusion model is derived to accurately predict the methane release process in coal. Additionally, temperature has a more important effect on transient diffusion coefficient than pressure. Thermal stimulation leads to a net increase rather than a decrease in diffusion coefficient in the early diffusion stages and can also accelerate the attenuation of diffusion coefficient, with this intensifying effect becoming more pronounced at higher temperatures. The research results can provide some reference for the determination of coal seam gas content and the selection of heat injection process parameters. [ABSTRACT FROM AUTHOR]

In this paper, we prove that under weak assumptions on the reaction terms and diffusion coefficients, a positive solution exists for a one-dimensional case and a positive radial solution to a multidimensional case of a nonlocal elliptic problem. Additionally, we establish the uniqueness of the solution, with the fixed point theorem being the primary tool employed. Our results are new and generalize several existing results. [ABSTRACT FROM AUTHOR]

The binder's choice holds immense significance in the quest for robust electrochemical performances of lithium/sodium‐ion battery's (LIB/SIB) electrodes. Conventional PVDF binder is a passive polymer lacking the ability to transport Li+/Na+ and facilitate ion kinetics. This limitation poses constraints in achieving high specific capacity, fast charging, and long cycle life. Herein, a novel water‐soluble concentrated imidazolium functionalized poly(ionic liquid), poly(oxycarbonylmethylene 1‐allyl‐3‐methyimidazolium) (PMAI) is synthesized, and evaluated it as binder in LIB/SIB. PMAI‐based anodic‐half cell exhibits excellent electrochemical performance, achieving higher capacities (297 mAhg−1 at 1C for LIBs and 250 mAhg−1 at 60 mAg−1 for SIBs) and good cycle stability (80 % capacity retention after 750 cycles for LIBs; 96% capacity retention after 200 cycles for SIBs), compared to PVDF binder. In addition, PMAI/Gr delivers a higher discharge capacity of 85 mAhg−1 than PVDF/Gr with 47 mAhg−1 at 5C. PMAI‐containing electrodes show better rate capability at different current densities than PVDF binder in LIB/SIB. The enhanced ion diffusion coefficient, lower resistance and decreased activation energy of desolvation, are ascribed to densely polar ionic liquid groups along the polymer and formation of a functionalized SEI via binder reduction. The novel PMAI binder's design and full‐cell examination confirm its potential in secondary‐ion battery applications. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the spatiotemporal patterns of solutions to diffusive nonlocal Nicholson’s blowflies equations, wherein a natural death rate of the immature population is included in the distribution function. We first prove the positivity and boundedness of positive solutions in the model by using the minimum principle and the method of lower and upper solutions. Subsequently, we conduct a detailed bifurcation and stability analysis to obtain conditions on all the diffusion coefficients and the death rate coefficient of the immature population required for the emergence of spatiotemporal patterns, including spatially nonhomogeneous time periodic orbits. Our results indicate that the model can undergo Hopf bifurcation when the diffusion rate of the mature population passes through a sequence of critical values. Additionally, we examine the dependence of Hopf bifurcation points and bifurcated oscillations on model parameters, including the diffusion rate and death rate of the immature population. Finally, we report numerical simulations based on the bifurcation analysis to demonstrate the theoretical results, and it will help us better understand the ecological characteristics and behavioral patterns of the blowfly population. [ABSTRACT FROM AUTHOR]

In this study, we use molecular dynamics (MD) simulation to predict the thermodynamics, structural, and transport characteristics of liquid para-hydrogen (para-H 2) over a wide temperature range. The Feynman–Hibbs (FH) technique employs Lennard-Jones pair potentials (LJ) which are enhanced by quantum modifications to describe molecular interactions. Results retain the FH's structural, thermodynamics and transport properties, and the classical LJ models (the radial distribution function, total energy, pressure, potential energy, enthalpy, diffusion coefficient, and shear viscosity). The datasets included in the paper were also considered, along with the experimental data collected, where possible. This work shows that for liquid para-H2, FH approach integrated to classical MD simulation, including quantum corrections yields an excellent accordance with the experimental findings. The FH potential improves concordance with the shear viscosity and diffusion coefficient values, as demonstrated by the results. With greater accuracy to experimental data, the FH Molecular Dynamics approach (FHMD) predicts such values. [ABSTRACT FROM AUTHOR]

Oxygen redox enhances the specific energy of sodium cathodes, but the other performance remains unsatisfactory. By introducing Cu into P2 lattice to replace Li cations, P3‐type Na0.75Li0.2Cu0.05Mn0.75O2 with high Na concentration is achieved. This modification induces notable alteration in the lattice structure, specifically increasing the interplanar spacing of NaO6 from 3.6 Å to 3.8 Å. The resultant P3‐type cathode delivers a remarkable capacity of 253 ± 1.3 mAh g−1 with energy density of 680 mWh g−1, setting a benchmark for P3‐type sodium cathodes. The high capacity can be attributed to the activation of Mn3+/ Mn4+ redox pair following Cu substitution. Further investigations confirm that Mn3+/ Mn4+, Cu2+/ Cu3+ and O2−/On− redox pairs all contribute to the high performance. The absence of O vacancy and the reduction in phase transitions enhance the cyclic performance with capacity retention of 86.3% at 0.5C. Additionally, the small diffusion energy barrier (34.6 KJ mol−1) results in a high Na diffusion coefficient (1.332 × 10−9 cm2 s−1), thereby promoting superior rate behavior with a capacity of 200.8± 2.1 mAh g−1 at 5C. These results demonstrate the advantages of the P3‐type Na0.75Li0.2Cu0.05Mn0.75O2 cathode over the other Na cathodes, suggesting high potential for application in high‐energy storage fields. [ABSTRACT FROM AUTHOR]

The current application of gel electrolytes in energy storage fails to meet the demand for higher ion transport and excellent mechanical properties due to the low ionic conductivity and poor mechanical properties. Herein, a novel strategy is proposed to graft oligomer polyetheramine on the surface of MXene to achieve a transformation from solid MXene to MXene nanofluid avoiding oxidation and aggregation of MXene, and then it is introduced to gel electrolytes providing ion transport channels and mechanical properties. The synergistic effect on the core of MXene and the canopy of polyetheramine produce Lewis acid–base interactions on electrolyte ions, which not only promote electrolyte dissociation but also provides ion transport path‐way. The experiment and molecular dynamics simulations show that the ionic diffusion ability of electrolyte ions is enhanced, because the MXene and polyetheramine promote electrolyte dissociation and reduce the electrostatic interference between anions and cations. The specific capacity of the assembled supercapacitor is 114.28 F g−1 at 1 A g−1 current density, and the capacity retention rate is 91.30% after 3000 cycles. This work provides a new insight for fabricating high‐performance devices. [ABSTRACT FROM AUTHOR]