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To observe and study complex biological interactions, establishing a simple simulated foundation is essential for identifying optimal solutions for the therapeutic behavior of different mediums. Using the Einstein-Langevin equation of Brownian motion, which accounts for both systematic and random forces acting on particles, this study explores the dynamic behavior of nanoparticles in two mediums: seawater and blood. With the addition of a smoothing algorithm, the results show that the diffusion coefficient in seawater is approximately 415% higher than in blood. Visual representations further confirm that seawater exhibits a greater scale of nanoparticle movement compared to blood. This study provides critical benchmarks for recalibrating models used in drug delivery and diagnostics, offering new pathways for therapeutic optimization. Additionally, it successfully quantifies the range gap in particle diffusivity between these two mediums. [ABSTRACT FROM AUTHOR]

The durability of recycled aggregate concrete (RAC) in the marine environment is mainly influenced by chloride attack. In this paper, the chloride transport law in RAC with different recycled coarse aggregate (RCA) contents was investigated by dry-wet cycling tests considering RCA volume fractions. A five-phase randomly convex polygonal aggregate model was built through a self-compiled program and then a mesoscopic numerical method was established by finite element software development. The proposed numerical model was validated by experimental results and data from other scholars. The impact of interfacial transition zone (ITZ), RCA, new mortar and old mortar were studied. The results showed that: 1) As the thickness of ITZ grows, the chloride diffusion coefficient increases in RAC. When the thickness of the ITZ rises from 25 µm to 100 µm, the chloride diffusion coefficient rises by 37%; 2) The diffusion coefficient of ITZ and mortar have a positive impact on the diffusion of chloride ion in RAC; 3) The chloride diffusion coefficient of RAC is positively correlated with the volume fraction of RCA (V RCA). The chloride diffusion coefficient increases by 102.0% as the V RCA increases from 0% to 50%. The proposed mesoscopic model not only effectively simulates the chloride attack process but also can be used to simulate other ionic attack behaviors and mechanical properties of RAC. [ABSTRACT FROM AUTHOR]

Diffusion is a mass transport phenomenon caused by chaotic thermal movements of molecules. Studying the transport in specific domain is simplified by using evolutionary differential equations for local concentration of the molecules instead of complete information on molecular paths [1]. Compounds in a fluid mixture tend to smooth out its spatial concentration inhomogeneities by diffusion. Rate of the transport is proportional to the concentration gradient and coefficient of diffusion of the compound in ordinary diffusion. The evolving concentration profile c(x,t) is then solution of evolutionary partial differential equation ∂c/∂t = DΔC where D is diffusion coefficient and Δ is Laplacian operator. Domain of the equation may be a region in space, plane or line, a manifold, such as surface embedded in space, or a graph. The Laplacian operates on smooth functions defined on given domain. We can use models of diffusion for such diverse tasks as: a) design of method for precise measurement of receptors mobility in plasmatic membrane by confocal microscopy [2], b) evaluation of complex geometry of trabeculae in developing heart [3] to show that the conduction pathway within the embryonic ventricle is determined by geometry of the trabeculae. [ABSTRACT FROM AUTHOR]

The clinical differences between odontogenic myxoma (OM) and odontogenic myxofibroma (OMF), and the clinical significance of their classifications, remain unclear. This study reviewed the clinicopathological characteristics of patients with OM or OMF and evaluated the fibrous component of the specimens. Medical records of 21 patients with OM or OMF who underwent tumour resection were reviewed. The percentage of fibrous tissue on the representative sections was evaluated using haematoxylin and eosin- and Masson's trichrome-stained specimens. Histopathological diagnoses included 11 OMs and 10 OMFs with no tumour recurrence except for two cases in which the dredging method was applied. More cortical bone perforation was observed in OM than in OMF cases, without significant differences. Location-locularity and apparent diffusion coefficient value (ADC)-cortical bone perforation were significantly correlated in all OM and OMF cases. The percentage of fibrous tissue in specimens showed bimodal distribution bordered by 45%. There was a significant association between diagnosis based on 45% fibrous tissue criterion and the final pathological diagnosis. Our study showed a tendency for cortical bone perforation in OM compared to OMF and correlation between ADC and cortical bone perforation. According to the histopathological analyses, the fibrous component of each case was bimodal with 45%, which may be a criterion to distinguish between OM and OMF. Accumulating knowledge, such as significant differences in prognosis, may allow for minimal surgical treatment options based on the diagnosis according to this novel histopathological criterion. [ABSTRACT FROM AUTHOR]

This study aimed to efficiently reduce the release of radon from water bodies to protect the environment. Based on the sizes of the experimental setup and modular float, computational fluid dynamics (CFD) was used to assess the impact of the area coverage rate, immersion depth, diffusion coefficient, and radon transfer velocity at the gas–liquid interface on radon migration and exhalation of radon-containing water. Based on the numerical simulation results, an estimation model for the radon retardation rate was constructed. The effectiveness of the CFD simulation was evaluated by comparing the experimental and simulated variation values of the radon retardation rate with the coverage area rates. The effect of radon transfer velocity on radon retardation in water bodies was minor and insignificant according to the appropriate value; therefore, an estimation model of the radon retardation rate of the coverage of a radon-containing water body was constructed using the synergistic impacts of three factors: area coverage rate, immersion depth, and diffusion coefficient. The deviation between the experimental and simulated results was < 4.3%. Based on the numerical simulation conditions, an estimation model of the radon retardation rate of covering floats in water bodies under the synergistic effect of multiple factors was obtained, which provides a reference for designing covering floats for radon retardation in radon-containing water. [ABSTRACT FROM AUTHOR]

Copyright of Science of Sintering is the property of National Library of Serbia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article investigates the stabilization issue of highly non-linear hybrid stochastic delayed networks (HSDNs) via periodic self-triggered control under impulse (PS-TCI). Firstly, the existence of a unique global solution for highly non-linear HSDNs under PS-TCI is studied. Then, a stabilization criterion for highly non-linear HSDNs is established, by combining a graph-theoretic approach with a novel Lyapunov-based analysis, based on a 'genuine' Lyapunov function defined by introducing an auxiliary timer. Therein, the less conservative polynomial growth condition and local Lipschitz condition for the drift and diffusion coefficients are used than the linear growth condition and global Lipschitz condition. Meanwhile, the design idea of PS-TCI is based on the evolution of an upper bound of the mathematical expectation for Lyapunov function (not directly Lyapunov function or system state), which implies that the triggered instant of PS-TCI is not a random variable. Finally the theoretical results are employed to study the stability of a class of FitzHugh–Nagumo circuits networks and the central pattern generators networks of a hexapod robot, and correlative numerical simulations are provided for demonstration. • The stabilization of highly non-linear HSDNs is first investigated via PS-TCI. • Some existing stabilization conditions for PS-TCI in [30,34] are weakened. • By introducing an auxiliary timer, a novel Lyapunov-based analysis is proposed. • The theoretical results could be applied to FNCNs and CPGNs successfully. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to analyze the association between magnetic resonance imaging apparent diffusion coefficient map value and histopathological differentiation in patients who underwent eye enucleation due to retinoblastomas. Methods: An observational chart review study of patients with retinoblastoma that had histopathology of the lesion and orbit magnetic resonance imaging with apparent diffusion coefficient analysis at Hospital de Clínicas de Porto Alegre between November 2013 and November 2016 was performed. The histopathology was reviewed after enucleation. To analyze the difference in apparent diffusion coefficient values between the two major histopathological prognostic groups, Student’s t-test was used for the two groups. All statistical analyses were performed using SPSS version 19.0 for Microsoft Windows (SPSS, Inc., Chicago, IL, USA). Our institutional review board approved this retrospective study without obtaining informed consent. Results: Thirteen children were evaluated, and only eight underwent eye enucleation and were included in the analysis. The others were treated with photocoagulation, embolization, radiotherapy, and chemotherapy and were excluded due to the lack of histopathological results. When compared with histopathology, magnetic resonance imaging demonstrated 100% accuracy in retinoblastoma diagnosis. Optic nerve invasion detection on magnetic resonance imaging showed a 66.6% sensitivity and 80.0% specificity. Positive and negative predictive values were 66.6% and 80.0%, respectively, with an accuracy of 75%. In addition, the mean apparent diffusion coefficient of the eight eyes was 0.615 × 103 mm2/s. The mean apparent diffusion coefficient value of poorly or undifferentiated retinoblastoma and differentiated tumors were 0.520 × 103 mm2/s and 0.774 × 103 mm2/s, respectively. Conclusion: This study revealed that magnetic resonance imaging is useful in the diagnosis of retinoblastoma and detection of optic nerve infiltration, with a sensitivity of 66.6% and specificity of 80%. Our results also showed lower apparent diffusion coefficient values in poorly differentiated retinoblastomas with a mean of 0.520 × 103 mm2/s, whereas in well and moderately differentiated, the mean was 0.774 × 103 mm2/s. [ABSTRACT FROM AUTHOR]

Anthraquinone-based molecules are promising electroactive materials for use in aqueous organic flow batteries. At high concentrations in aqueous solutions, the well-known negolyte molecule anthraquinone disulfonic acid (AQDS) molecule has been observed to aggregate under near-neutral and acidic conditions. Aggregation has been hypothesized to be directly linked to observed concurrent capacity reduction. In this study, we investigated three different water-soluble anthraquinones in electrolytes of varying compositions and pH to gain further insight into the possible causes of capacity loss. We used low-field benchtop 1H-NMR and diffusion NMR measurements directly in non-deuterated aqueous flow-battery electrolytes to investigate molecular aggregation. Single-cell testing was performed under exhaustive electrolysis conditions to determine the number of electrons exchanged per molecule. We observed a decrease in the number of electrons exchanged per molecule in the presence of carbonate ions due to CO2 adduct formation. The aggregation constants were determined from both concentration-dependent chemical shifts and self-diffusion coefficients. We show that aggregation of the oxidized form of all three molecules studied here occurs under near-neutral and alkaline conditions and does not affect the number of accessible e−. [ABSTRACT FROM AUTHOR]

The goal of this paper has been to add an experimental data set for drying a meat product and provide a comparison with well-established thin-layer drying models. This article presented experimental investigations on the convective drying of Polish sausage slices at a temperature of 40°C. Slices have been in the thickness of 3 to 8mm. Measurements of mass loss and size change were performed. The data have been presented in the form of standard drying kinetics. Additionally, the estimation of the diffusion coefficient according to the simplified graphical approach is made. Based on the best-fit approach the coefficients for typical semiempirical correlations for MR (moisture ratio) estimation have been calculated and presented. [ABSTRACT FROM AUTHOR]

The aim of this work to explore the absorption behavior of bio composites reinforced with date palm fibers. RSM and ANOVA were utilized to evaluate the impact and interdependence of input variables (Time: from 24 h to 672 h, Fiber content: 15 %, 20 %, and 25 %, and types of water: seawater, distilled water, and rainwater) on the output variables (Mass of CDPF) during a water absorption process that lasted more than 670 h at 23 °C. The findings revealed that the bio composites with the above-mentioned filler content absorbed more water as the amount of fibers increased, with absorption rates of 14.03 %, 19.39 %, 30.94 % for seawater, 15.42 %, 20.64 %, and 36.08 % for distilled water, and 16.37 %, 21.98 %, and 42.10 % for rainwater, respectively. Additionally, the study measured the diffusion coefficient of bio composites, which had a minimum value of about 2.11 × 10−6mm2/s and a maximum value of about 3.99 × 10−6mm2/s. The results of RSM model analysis showed that this model is accurate and reliable. Where the values of R2 and adjusted R2 coefficients for the Mass of CDPF were 99.63 % and 99.61 %, respectively, indicating an ideal match between experimental and predicted values. These findings provide valuable information for engineers interested in incorporating date palm fiber bio composites during development and implementation. [ABSTRACT FROM AUTHOR]

Comparison of some experimental data and deterministic dynamical models of heartbeat show that it is essential to consider stochastic mathematical models. The Zeeman heartbeat model is one of the main heartbeat models whose stochastic dynamics is less studied. Especially, investigating bifurcations in stochastic dynamical models can be useful for identifying abnormal cardiac rhythms. This paper is concerned with two essential features of the two dimensional stochastic Zeeman heartbeat model i.e., stability and bifurcation. To achieve this approach, Taylor expansion, polar coordinate transformation, and stochastic averaging procedure will be used to convert the classical system into an Itô averaging diffusion system. Furthermore, we consider several theorems which provide sufficient conditions of drift and diffusion coefficients to establish stochastic stability, D-bifurcation and phenomenological bifurcation of the model. In the end, numerical simulation plays an important role to show the influences of the noise severity and confirm our theoretical results. [ABSTRACT FROM AUTHOR]

Owing to the features (high safety, inexpensive and environmental friendliness) of aqueous rechargeable Mg-ion batteries (ARMIBs), they have drawn extensive attention in the future energy storage systems. However, the poor Mg2+ migration kinetics during the Mg2+ intercalation/extraction still hinders the progress of developing suitable cathode materials. Herein, a layered buserite Mg-Mn oxide (MMO) material with large interlayer space (∼9.70 Å) and low-crystalline structure is studied as a high-performance cathode in ARMIBs. Compared with the counterpart, the Mg2+ migration kinetics of the MMO cathode can be enhanced by its unique structure (bigger interlayer spacing and low-crystalline structure). The layered buserite MMO as a high-performance ARMIBs cathode exhibits high Mg storage capacity (50 mA g−1: 169.3 mAh g−1), excellent rate capability (1000 mA g−1: 98.3 mAh g−1), and fast Mg2+ migration (an average diffusion coefficient: ∼4.21 × 10−10 cm2 s−1) in 0.5 M MgCl 2 aqueous electrolyte. Moreover, the MMO-1//AC full battery achieved a high discharge capacity (100 mA g−1: 111 mAh g−1), and an ignored fading over 5000 cycles (1000 mA g−1). Therefore, layered Mg-Mn oxide with large interlayer space may break a new path to develop the promising ARMIBs. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are major chemical pollutants in indoor air. Indoor fabrics, such as curtains, carpets, sofas, and clothes, strongly adsorb VOCs due to their high loading rates and large specific surface areas. The desorption of VOCs from these fabrics can act as a secondary source, worsening indoor air pollution and prolonging its effects. The diffusion coefficient is a key parameter that determines the source-sink properties of fabrics. In this study, the VOC diffusion characteristics in fabrics were investigated through microstructural examination, mass transfer analysis, and environmental chamber experiments. Yarn and fiber gaps were identified as dual mass transfer channels within the fabrics and were represented using two distinct fractal models. A dual-porosity medium (DPM) model, based on these fractal representations, was developed to predict the VOC diffusion coefficients in indoor fabrics and was validated via experiments under various environmental conditions and fabric-VOC combinations. The results highlight the significant impact of fabric structure and composition on VOC adsorption and emission dynamics. The validated DPM model provides a comprehensive approach to predicting VOC diffusion in fabrics, providing a more accurate method for assessing indoor air quality and fabric-mediated human exposure. [Display omitted] • Indoor fabrics act as both sources and sinks for VOC transport. • Yarn and fiber gaps are identified as key diffusion channels in fabrics. • A fractal-based DPM model is developed for VOC diffusion in fabrics. • Experiments and model comparisons confirm the reliability of the DPM model. [ABSTRACT FROM AUTHOR]

This study investigates tumor density dynamics through computational modeling, focusing on key parameters: proliferation rate m , diffusion coefficient τ , and additional factors c and κ. Systematic exploration reveals nuanced interactions shaping tumor growth, regression, and dispersal. Higher m values accelerate proliferation, while increased τ facilitates dispersal. Parameters c and κ further refine our understanding of tumor behavior. These insights inform the development of computational models for oncological research, with implications for targeted therapeutic interventions. The aim can be realized by utilizing the propose Finite Volume Method to develop a representation of cancer models and improve the efficiency of their simulations. Furthermore, the numerical results will be validated by comparing them with the Tanh-Coth method formulation to assess the model's accuracy and efficiency. The findings suggest that accurate modeling of tumor dynamics can aid in predicting tumor progression and response to treatments, ultimately contributing to personalized medicine and more effective therapeutic strategies. Phase plane analysis shows the schemes are conditionally stable and accurate to the fourth order in time. The method demonstrates exceptional agreement and error-free findings compared to 3D plots, underscoring its potential utility in clinical and research settings. [ABSTRACT FROM AUTHOR]

Nonferrous impurities such as Cu, Zn, and Co, along with inert materials such as gangue and silica in pyrite cinder (PyC), significantly limit its direct use as an iron source for battery-grade ferric phosphate (FP) or lithium iron phosphate (LFP). To address this issue, a new process using alkali excitation, mechanical activation, and aging to remove impurities from PyC was developed. Additionally, a novel method for preparing carbon-coated lithium iron phosphate (LFP@C) using purified PyC (p-PyC) as the iron source was explored. With 20% NaOH, 3 h of ball milling activation, and aging at 200 ℃ for 4 h, the Fe content in PyC increased to 55.14%, with a recovery rate of 95.43%. Compared with those in untreated PyC, the Fe leaching rate in p-PyC reached 98.25%, and the levels of Al, Cu, Zn, Co, and Si in the acid-leaching liquor were reduced by 96.62%, 96.67%, 99.85%, 75.96%, and 99.99%, respectively. The LFP@C cathode material was directly prepared via carbothermal reduction using acid-leaching liquor from p-PyC as the iron source. The LFP@C-30% crystal particles were well connected, and the surface was effectively coated with a carbon layer to form a conductive layer. At 0.1 C, the specific capacity was 159.09 mAh·g−1, with 95.63% capacity retention after 100 cycles. LFP@C-30% presented the lowest charge transfer resistance and an apparent diffusion coefficient (D Li) of 2.33×10−11 cm2·s−1. This study offers a simple and effective method for removing impurities from PyC and presents a new approach for converting PyC into high-demand FPs or LFPs. [Display omitted] • A new process of alkali excitation-mechanical activation-aging for PyC was developed. • Harmful impurities in PyC can be converted to soluble or acid-insoluble components. • The acid-leaching liquor from p-PyC can be directly used to prepare battery-grade FP. • The D Li of LFP@C-30 % is 2.33×10−11 cm2·s−1, showing superior Li+ diffusion behavior. • A discharge-specific capacity of 159.09 mAh·g−1 at a 0.1 C rate was achieved. [ABSTRACT FROM AUTHOR]

The analysis is generally conducted in stationary receiver and transmitter models in a diffusion environment for the fundamental Molecular communication (MOC) models. However, a mobile MOC model is employed in this study, deviating from the existing literature. This mobile MOC model considers the mobility of all variables in the diffusion environment, including the transmitter, receiver, and molecules. Firstly, a novel MOC model is proposed, departing from the conventional normal distribution for the mobility of variables. Instead, alternative distribution functions such as the Pareto distribution, extreme value distribution, t -distribution, and generalized extreme value distribution are employed. Furthermore, the system's performance is enhanced by optimizing the distribution function and model parameters, such as the diffusion coefficient, using the optimization of optimization (OtoO) approach. In this approach, the Multi-Verse Optimization (MVO) algorithm serves as the primary algorithm, while the Grey Wolf Optimization (GWO) algorithm functions as the auxiliary algorithm. Essentially, the MVO algorithm optimizes the parameters of the MOC model, while simultaneously, the GWO algorithm optimizes the impact of the optimization processes of MVO on the parameters ''p'' and ''N'' as well as the constant parameter of the distribution function. By optimizing both the parameters of the MOC model and the distribution function, the number of received molecules is significantly increased. Therefore, this study not only improves the results of the MOC model structure based on different distribution functions but also optimizes all parameters of the proposed model using the MVO-GWO OtoO approach. [ABSTRACT FROM AUTHOR]

There are approximately 600 km (370 mi) of railway passing through the desert areas in Iran. One of the important challenges associated with the degradation of railway structures in desert areas is chloride-ion invasion of the concrete, which causes the corrosion and swelling of bars, leading to the total destruction of concrete sleepers. Although numerous studies have been conducted on the prediction of bar corrosion in various reinforced concrete structures, there is no specific study on the prediction of bar corrosion in B70 concrete sleepers. This study investigates chloride diffusion in concrete sleepers and develops a prediction model using field and laboratory measurements. Sample profiles were taken from the Bam-Zahedan railway line for the determination of diffusion coefficients and initial and surface chloride contents. The early-age diffusion coefficient in concrete samples was obtained, and a prediction model was developed based on these parameters. Finally, a sensitivity analysis was performed in order to investigate the influential parameters on the initiation time of the corrosion. The results indicate that the effects of the chloride diffusion coefficient and the concrete cover were the leading factors in the corrosion initiation time. [ABSTRACT FROM AUTHOR]

Copyright of Cukurova Medical Journal / Çukurova Üniversitesi Tip Fakültesi Dergisi is the property of Cukurova University, Faculty of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To have a better understand on the change of microstructure via kinetics, the diffusion behavior of Mg alloys is of special interest to researchers. Meanwhile, diffusion coefficients of Mg based alloys can explain and represent their diffusion behavior well. The evolution of experimental and calculated methods for detecting and extracting diffusion coefficients was discussed briefly. The reasonable diffusion data, especially self-diffusion coefficients, impurity diffusion coefficients and inter-diffusion coefficients of Mg alloys, were reviewed in detail serving to design the Mg alloys with higher accuracy. Then the practical applications of diffusion coefficients of Mg alloys were summarized, including diffusional mobility establishing, precipitation simulation and mechanical properties prediction. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nickel-rich layered oxides (Ni ⩾ 90%) have been recognized as a promising cathode material for Lithium-ion batteries (LIBs) owing to their high energy density and low cost. Herein, we prepared 20 LiNi0.90Co0.06Mn0.04O2 (Ni90) samples with various morphologies by regulating sintering temperature and the lithium to transition metal ratio. The correlation between the synthesis conditions, structural properties, and electrochemical performance of Ni90 materials was thoroughly investigated during the evolution from polycrystal to single crystal. A positive and linear relationship was found between sintering temperature and primary particle size (PPS), which affect the electrochemical performance profoundly. Polycrystals with small PPS show a high discharge capacity and low polarization, while single crystals with large PPS have low discharge capacity but excellent cycling stability. Moreover, the sluggish kinetic properties of Ni90 materials at the end of discharge (a sharp drop in lithium-ion diffusion coefficient at the end of discharge) lead the morphology factors to a critical feature that dominates the total discharge capacity. Taking discharge capacity and cycling stability into integrated consideration, the quasi-single crystal Ni90 materials with moderate PPS and the lowest cation disordering is the first choice. These findings contribute to a better understanding of polycrystalline and single-crystal Nickel-rich cathode materials for LIBs. [ABSTRACT FROM AUTHOR]

Numerous experiments have demonstrated that the porous support layer limits the diffusion behavior and leads to a reduction in permeability of thin film composite (TFC) membranes. Although this geometric restriction has been described using empirical models, it is still rough and unable to describe the effect of support layer on selectivity, an accurate theoretical model to quantitatively calculate the permeation performance of TFC membranes is lacking. In this study, an equivalent theoretical model is proposed to describe the mass transfer process of TFC membrane, by properly handling the tangential diffusion at the interface between the selective layer and the support layer. Both the computational fluid dynamics (CFD) simulations performed in this work and experimental data in some literatures prove the validity of the equivalent model. Analysis of the theoretical model and CFD simulation results show that: Restriction factor Ψ is independent of the solubility coefficients but dependent of the diffusion coefficients and support layers, which would alter the TFC membrane selectivity to the diffusing species with different diffusion coefficients. Tuning the structural parameters of the support layer is an effective way to bring the performance of TFC membranes closer to that of ideal free-standing membranes. Among them, High surface porosity of the support layer is the most critical factor affecting TFC membrane performance, both for permeability and selectivity. • It reveals the selective attenuation mechanism of TFC membranes. • It provides a theoretical calculation method for the separation performance of TFC membranes. • It provides guidance for the experimental preparation of TFC membranes. [ABSTRACT FROM AUTHOR]

The large-scale application of membrane distillation (MD), an important method for desalting seawater, is limited due to membrane fouling. In this study, ethyl orthosilicate (TEOS) was polymerized to obtain different nSiO 2 particles. Vinyl triethoxysilane (VTES) was hydrolysed and polycondensation was used to produce spherical polyethylene-sesquioxane (PVSQ) microparticles, which were modified to construct micro/nano particles. Then grafted on the surface of polyvinylidene fluoride (PVDF) composite membrane. The low-surface-energy hydrophobic groups present on the surfaces of the vinyl and ethoxy particles greatly enhanced the membrane hydrophobicity. The particle size of nSiO 2 can change the properties of the membrane. The separation performance of the membrane was tested by direct contact membrane distillation (DCMD). In the separation of a constant concentration of feed solution (3.5 wt% NaCl), the membrane flux was relatively stable at 23.8 kg·m−2·h−1, and the salt interception rate reached 99.99 %. In the subsequent separation of a salt/humic acid solution, the flux remained stable and the good anti-fouling performance indicating that this system outperformed the unmodified membrane. Finally, the effect of different cations on the water diffusivity was studied using a molecular simulation method. Both Ca2+ and Mg2+ reduced the diffusion coefficient of water. However, when these two ions were present simultaneously, Ca2+ inhibited the binding of Mg2+ to water, and the diffusion coefficient of water increased. This study provides a novel approach for preparing hydrophobic membranes for the separation of complex brines. • Vinyltriethylxysilane and nSiO 2 to construct micro/nanoparticle. • Micro/nanoparticle binds to the hydroxyl of membrane in alkaline environment. • These particles were combined with nSiO 2 to create a rough membrane surfaces. • The low-surface-energy hydrophobic groups enhanced the membrane hydrophobicity. • A high membrane flux and salt interception rate were obtained. [ABSTRACT FROM AUTHOR]

Purine derivatives present a high efficiency for anti-corrosion purposes while the nanoscale mechanisms are not yet fully understood. In this work, the inhibition mechanism of the 2,6-dithiopurine (DTP) molecule was investigated using advanced characterizations and atomic simulations. We revealed that the DTP molecule undergoes a multi-layer adsorption mode and is governed by both chemisorption and physisorption processes. An organometallic layer at a thickness of ∼3.8 nm was captured using TEM, comprised of Fe-N and Fe-S bonds strongly anchored to the iron interfaces, as confirmed by the XPS analysis. Our quantum chemical calculations showed that heteroatoms such as N or S in the DTP molecule offer reactive sites that facilitate its chemisorption onto iron surfaces, to form metal-organic bonds (specifically, Fe-N and Fe-S) at the DTP-iron interfaces. We further employed molecular dynamics simulations to investigate the interaction between DTP molecule and various substrates. Our findings suggest that the hydroxyl groups on the lepidocrocite surface can significantly promote bonding between DTP and iron surfaces. Based on large-scale molecular dynamics simulations, we discovered that DTP can exhibit a strong binding affinity for aggressive ions, leading to a considerable decrease in the self-diffusion coefficient of hydronium ions of up to 70 %. This work provides a new understanding of anti-corrosion mechanisms and offers opportunities to design new corrosion inhibitors possessing multiple reactive sites and strong bonding with the substrate. [Display omitted] • An DTP-Fe organometallic layer is directly captured. • DTP molecule adopts a mode of multi-layer adsorption, governed by both chemisorption and physisorption. • Different metal substrates play a role in the adsorption modes. [ABSTRACT FROM AUTHOR]

Niobates are regarded as prospective Li+-storage anode candidates due to the rich chemistry of niobium and crystal-structural openness. However, the exploration of niobates is still insufficient. In this study, we explore CuNb3O8 with a large theoretical capacity is 341.9 mAh g–1 as a high-performance anode compound. The reversible redox reaction among Nb5+, Nb4+ and Nb3+ during lithiation/delithiation is confirmed by ex-situ XPS, and a large reversible capacity of 231.8 mAh g–1 and safe lithiation potential of 1.53 V are achieved at 0.1 C. An intercalation-type Li+-storage mechanism is confirmed by in-situ XRD after the first lithiation process, guaranteeing the good cyclability from the second discharge–charge cycles. The Li+ diffusivity in CuNb3O8 is systematically and carefully studied. The galvanostatic intermittent titration technique tests show large Li+ diffusion coefficients of 1.2 × 10–12/1.5 × 10–12 cm2 s–1 during lithiation/delithiation, and the corresponding values obtained through the cyclic voltammetry technique are similar (2.2 × 10–12/3.0 × 10–12 cm2 s–1). Additionally, CuNb3O8 is successfully coupled with LiFePO4, and the resultant CuNb3O8//LiFePO4 full cell also exhibits good electrochemical properties, demonstrating the practicability of CuNb3O8 for large-scale energy-storage applications. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Molecular dynamics was used in this study to understand the selfhealing behavior and mechanism of asphalt. Density, solubility, and mean square displacement parameters were analyzed to confirm the validity of the matrix asphalt model. Molecular simulation software was used to develop a microscopic matrix asphalt self-healing model at the nanoscale. Cracking width of asphalt microcracks was represented by setting different vacuum layer thicknesses as the asphalt self-healing model. Density and diffusion coefficient of the self-healing model were obtained by running the molecular software to understand the entire process of asphalt healing. The self-healing mechanism of the matrix asphalt was analyzed. Results showed that the entire self-healing process of asphalt could be clearly divided into four stages, namely, external environment energy endowment, model end healing, asphalt microcrack healing, and self-healing model self-diffusion stages. Molecules of each component in the asphalt self-healing process diffuse and move mutually under constant temperature conditions. The diffusion coefficient of saturated components and polar aromatic was higher than that of asphaltenes and aromatic components. [ABSTRACT FROM AUTHOR]

Dendritic growth is a leading cause of degradation and catastrophic failure of lithium-metal batteries. Deep understanding of this phenomenon would facilitate the design of strategies to reduce, or completely suppress, the instabilities characterizing electrodeposition on the lithium anode. We present a linear-stability analysis, which utilizes the Poisson-Nernst-Planck equations to describe Li-ion transport and, crucially, accounts for the lack of electroneutrality. This allows us to investigate the impact of electric-field gradients near the electrode surface on both ion diffusion and its anisotropy. Our analysis indicates that the use of anisotropic electrolytes (i.e., electrolytes with anisotropic diffusion coefficients of the Li ions) and the control of the local electric field can suppress dendritic growth of lithium metal. Specifically, changes in the local electric field can be used to enhance the longitudinal (perpendicular to the electrode) component of the cation diffusion coefficient tensor, which decreases the maximum growth rate of the dendrites. Electrolytes with electric field-dependent diffusion coefficients would reduce dendritic growth in small batteries, while anisotropic electrolytes (or separators with anisotropic pore structures or columnized membranes) are appropriate for batteries of any size. [ABSTRACT FROM AUTHOR]

Fluxes of negatively charged ligand-coordinated iron, Fe(CN)63/4-, and chromium, CrPDTA1/2−, through two promising commercial cation-exchange membranes, Aquivion E87–05S and Fumasep E-620(K), were measured as functions of current density. The magnitude of the partial current density reached a maximum of∣− ∣ 43 μA cm−2 at the maximum applied current density magnitude of ∣− ∣ 43 mA cm−2 for Fe(CN)6 3/4− transport through Aquivion, or 0.1% of the total current density. Fumasep E-620(K) blocks practically all crossover of both compounds. Both membranes sorb more Fe(CN)6 3/4− and CrPDTA1/2− than predicted by Donnan equilibrium, and low crossover rates can be attributed mainly to slow diffusion, not charge-based rejection of co-ions. The magnitude of the diffusion coefficient appears to correlate with hydraulic permeability. Although Aquivion E87–05S and Fumasep E-620(K) have significant and observable differences in membrane crossover rates, cells built with the DI-soaked membranes offer similarly high coulombic efficiency, indicating the relatively small contribution that crossover makes to inefficiency over a single cycle. [ABSTRACT FROM AUTHOR]

The hydroxide-exchange-membrane water electrolyzer (HEMWE) is a promising means to store intermittent renewable energy in the form of hydrogen chemical energy. The hydroxide-exchange ionomer (HEI) in the gas-evolving electrodes and the hydroxideexchange membrane (HEM) are key components of HEMWE. In this work, we simulate the cell and examine explicitly the impact of HEI and HEM properties with a focus on improving HEMWE performance when operated with distilled water (i.e., no supporting electrolyte). The tradeoff between the ionic conductivity gain and electrochemically active surface area (ECSA) loss is studied. For a constant catalyst loading, distributing more catalyst next to the HEM or making thinner but denser catalyst layer is beneficial for HEMWE performance. The results demonstrate that a higher water diffusion coefficient is desired for HEM to supply reactant water to the cathode. In contrast, a lower water diffusion coefficient is preferred for the cathode HEI to retain the water in the regions with high reaction rates. Overall, the findings provide important insights to optimizing HEI/HEM materials for improved HEMWE performance. [ABSTRACT FROM AUTHOR]

A simple and sensitive electrochemical sensor was developed to quantify ciprofloxacin by restricted electro-polymerization of aniline on GCE followed by drop coating functionalized MWCNTs. Electro-catalytic activity of modified electrodes was investigated by EIS and CV revealed decrease in electrode's charge transfer resistance and increase in electron transfer kinetics. Effect of pH and scan rate suggests a mixed adsorption-diffusion process. Tafel slope (plot of ln|ja| or ln|Ia| against E) with linear relationship of potential vs logarithm of current on the linear sweep voltammogram determined the electron transfer coefficient (a). Using the value of (a), number of electrons (n) involved in the rate determining step was obtained. Surface coverage of analyte molecules adsorbed, and diffusion coefficient of ciprofloxacin were estimated from the Laviron and Randles Sevcik equations respectively. Peak current obtained by LSV for various concentrations of ciprofloxacin exhibited two linear ranges, 0.1 µM to 1 µM and 1 µM to 20 µM, with limit of detection 0.08 µM (RSD = 2.4%, S/N = 3). Presence of species existing abundantly in the sample matrix do not affect the sensor signal. Proposed ciprofloxacin sensor demonstrated high reproducibility, long-term stability and fast reaction. The fabricated sensor successfully determined ciprofloxacin in pharmaceutical formulations with recoveries between 92 to 104%. [ABSTRACT FROM AUTHOR]

A new in situ optical microscopy set-up is introduced which allows direct observation of cross-sections of Li-ion full cells in combination with simultaneous recording of electrochemical data. The method is validated by comparison of electrochemical data from coin full cells. Color changes give insights into processes on the electrode and particle level, such as lithiation behavior and electrode thickness changes. Our observations allow the evaluation of (i) the speed of lithiation fronts for LiC12 and LiC6 through anode coatings, (ii) estimation of apparent diffusion coefficients from analysis of the color distribution in single graphite particles, as well as (iii) electrical de-contacting and re-contacting of single graphite particles in connection with (iv) electrode thickness changes. Furthermore, our direct observations from the inside of full cells give indirect insights into aging phenomena such as Li plating and SEI growth. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The possibility of silicon electrodeposition from the low-melting LiCl-KCl-CsCl-K2SiF6 electrolytes has been studied. The stability of a silicon-containing additive was studied by cyclic voltammetry, and the rate constant of the chemical reaction of SiF4 release at a temperature of 827 K was calculated. It is determined that the constants of velocity values in the melt based on eutectic composition are 2 orders of magnitude higher, which indicates a higher rate of formation of volatile compounds. Cyclic voltammetry was also used to study the electrochemical behavior of K2SiF6 in the melts under study. It was found that the silicon electroreduction at the cathode is not reversible and proceeds in one 4-electron reaction. The diffusion coefficient calculated by the Matsuda-Ayabe equation was 0.72·10-5 cm²·s-1 at temperature of 823 K. According to the obtained voltammograms, the parameters for the silicon electrodeposition were selected. At a potential of -0.4 V vs QRE, dendritic silicon deposits were obtained. [ABSTRACT FROM AUTHOR]

Background: The sinonasal region is affected by a variety of neoplasms. A differentiation between benign and malignant masses is essential both for management and prognostication. Morphological analysis often does not allow this differentiation. Objectives: This article aims to assess the value of advanced MRI (diffusion [DWI] and dynamic contrast enhanced MRI [DCE-MRI]) in differentiation of benign and malignant sinonasal masses. Methods: This prospective study included 40 patients with sinonasal masses who underwent advanced MR on 3T MR scanner. The lesions were analyzed based on morphological characteristics, qualitative, quantitative diffusion parameters, and time signal intensity curves. Apparent diffusion coefficient (ADC) values were acquired using b values of 50 and 1000 s/mm2. The accuracy of DWI, DCE-MRI, and combined DWI/DCE-MRI in differentiating benign from malignant sinonasal masses were analyzed. Results: Perineural extension and growth pattern of the tumor were the best morphological discriminators. Mean ADC values for benign and malignant lesions were 1.675 ± 0.561 and 0.903 ± 0.405 × 10−3 mm2/sec,,respectively. ROC revealed that ADC cutoff value of 1.005 × 10−3 mm2/sec provided an accuracy of 92.5% in differentiating benign from malignant masses (P value <.01). On excluding the benign vascular masses (Juvenile Nasopharyngeal Angiofibroma and hemangioma), the time signal intensity curve showed 78% accuracy (P value <.001). The highest diagnostic performance was achieved by combining DWI and DCE-MRI (95% accuracy). Conclusion: DWI has higher accuracy than DCE-MRI. Quantitative DWI is preferable over qualitative DWI. Accuracy of DCE-MRI can be increased by excluding vascular masses with characteristic imaging features. DWI and DCE-MRI have the highest accuracy when used in combination than either of them alone in differentiating benign from malignant sinonasal masses. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the role of diffusion-weighted imaging (DWI) with histogram analysis of apparent diffusion coefficient (ADC) maps in the characterization of parotid tumours. This prospective study included 39 patients with parotid tumours. All patients underwent magnetic resonance imaging with DWI, and ADC maps were generated. The whole lesion was selected to obtain histogram-related parameters, including the mean (ADC mean), minimum (ADC min), maximum (ADC max), skewness, and kurtosis of the ADC. The final diagnosis included pleomorphic adenoma (PA; n = 18), Warthin tumour (WT; n = 12), and salivary gland malignancy (SGM; n = 9). ADC mean (×10−3 mm2/s) was 1.93 ± 0.34 for PA, 1.01 ± 0.11 for WT, and 1.26 ± 0.54 for SGM. There was a significant difference in whole lesion ADC mean among the three study groups. Skewness had the best diagnostic performance in differentiating PA from WT (P = 0.001; best detected cut-off 0.41, area under the curve (AUC) 0.990) and in discriminating WT from SGM (P = 0.03; best detected cut-off 0.74, AUC 0.806). The whole lesion ADC mean value had best diagnostic performance in differentiating PA from SGM (P = 0.007; best detected cut-off 1.16 × 10−3 mm2/s, AUC 0.948). In conclusion, histogram analysis of ADC maps may offer added value in the differentiation of parotid tumours. [ABSTRACT FROM AUTHOR]

Copyright of Cukurova Medical Journal / Çukurova Üniversitesi Tip Fakültesi Dergisi is the property of Cukurova University, Faculty of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work examines the behavior of geometric mean of concentrations in various conditions when there is no electric current and studies the reversal permanent charge problem, the charge sharing seen in x-ray diffraction. The geometric mean of concentrations is an average of concentrations, which indicates the central tendency of concentrations by using the product of their values. Observations are acquired from analytical results established using geometric singular perturbation analysis of classical Poisson-Nernst-Planck models. For ionic mixtures of multiple ion species, Mofidi and Liu [SIAM J. Appl. Math. 80 (2020), 1908–1935] centered two ion species with unequal diffusion constants to acquire a system for determining the reversal potential and reversal permanent charge. They studied the reversal potential problem and its dependence on diffusion coefficients, membrane potential, boundary concentrations, etc. Here, we look at the dual problem of reversal permanent charge, its uniqueness, and its dependence on other conditions with the same approach. We consider two ion species with positive and negative charges, say Ca+ and Cl−, to determine the specific requirements under which the permanent charge is unique. Furthermore, we investigate the geometric mean of concentrations for various membrane potential and permanent charges values. [ABSTRACT FROM AUTHOR]