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Activated carbons play an important role in enabling Li-ion batteries for high-power applications. They are well established in the application side of energy storage but remain untouched for integration toward conceptualization. As conceptualization attracts growing interest in the field of energy storage, more work needs to be done to bridge the gap between application and concept. Being a part of closing the gap between experiment and modeling, an electrochemical parameterization of commercial activated carbons having different specifications was investigated within the present study. The apparent Li-ion diffusion coefficient and exchange current density of different activated carbons were calculated. Results confirmed that the Li-ion diffusion coefficient was promoted by the ordered structure. Electronically conductive activated carbons exhibited low charge-transfer resistance and, hence, high exchange current density. Besides, long-term capacity retention is strongly linked with the activated carbons’ degree of structural order. According to the simulated discharge capacities extracted from the simplified 1D full-cell model with LiMn2O4-Activated Carbon cell chemistry, a notable improvement was observed in comparison with reference LMO-Graphite systems at all C-rates. Nevertheless, activated carbons proved their significance at especially high rates. When 20C was applied, a strong correlation can be built with the long-term cyclic behavior of activated carbon half-cells.

Hydride formation in zircaloy-4 under cyclic thermomechanical loading has been investigated using characterized notched beam samples in four-point beam testing, and microstructurally-representative crystal plasticity modelling of the beam tests which incorporates an atomistically-informed thermodynamically-equilibrium model for hydrogen concentration. The model provided the locations within the microstructure of high hydrogen content, above that required for saturation, hence predicting the anticipated locations of hydride observations in the experiments. The strain rate sensitivity of this alloy over the temperature range considered led to considerable intragranular slip and corresponding stress redistribution, and cyclic strain ratcheting leading to high hydrostatic stresses and in turn hydrogen concentrations, which explains the locations of experimentally observed hydride formation. The interstitial hydrogen interaction energy as well as the intragranular geometrically necessary dislocation density were shown to be important in controlling the spatial distributions of observed hydrides.

In 2011, this journal published the paper ‘A Boltzmann transformation method for investigation of water vapour transport in building materials’, proposing a dynamic measurement of building materials’ vapour permeability via the Boltzmann-Matano method. This critique points out that this publication is flawed, since it proposes an invalid approach and presents erroneous results. The analysis first shows that the presented vapour permeability values cannot be reproduced and instead far lower vapour transport properties are obtained. These corrected outcomes are however also much below the dry-cup reference values, and it is established that these deviations stem from the invalidity of the proposed approach, due to disregarding the material’s hygroscopicity. Given its erroneous results and invalid approach, it is finally recommended to have the paper officially retracted by the journal.

The brain extracellular space (ECS) is a continuous reticular compartment that lies between the cells of the brain. It is vast in extent relative to its resident cells, yet, at the same time the nano- to micrometer dimensions of its channels and reservoirs are commonly finer than the smallest cellular structures. Our conventional view of this compartment as largely static and of secondary importance for brain function is rapidly changing, and its active dynamic roles in signaling and metabolite clearance have come to the fore. It is further emerging that ECS microarchitecture is highly heterogeneous and dynamic and that ECS geometry and diffusional properties directly modulate local diffusional transport, down to the nanoscale around individual synapses. The ECS can therefore be considered an extremely complex and diverse compartment, where numerous physiological events are unfolding in parallel on spatial and temporal scales that span orders of magnitude, from milliseconds to hours, and from nanometers to centimeters. To further understand the physiological roles of the ECS and identify new ones, researchers can choose from a wide array of experimental techniques, which differ greatly in their applicability to a given sample and the type of data they produce. Here, we aim to provide a basic introduction to the available experimental techniques that have been applied to address the brain ECS, highlighting their main characteristics. We include current gold-standard techniques, as well as emerging cutting-edge modalities based on recent super-resolution microscopy. It is clear that each technique comes with unique strengths and limitations and that no single experimental method can unravel the unknown physiological roles of the brain ECS on its own. This work was supported by the grants from the Spanish Ministry for Research and Innovation SAF2017-83776-R and RYC-2014-15994 to JT, IJCI-2017-32114 to FS, University of the Basque Country grant GIU18/094 to OP and JT, and a Basque Government grant PIBA 2019-65 to JT.

Nanoconfined ions have dramatically different local environments compared to the bulk, which profoundly affects the ion solvation and transport properties taking place in the confined space. Herein, we investigate the rotational and translation mobility of both cation and anions of an OIPC (diethyl)(methyl)(isobutyl)phosphonium hexafluorophosphate) confined in 40 and 180 nm straight-through Al2O3 pores. The results revealed that the nanoconfined OIPC exhibit 44 times higher ionic conductivity than the bulk material at 30 degrees C. This enhancement is attributed to both the reduced tortuosity and the increased population of mobile species. More interestingly, the Al2O3 nanochannels were found to selectively enhance the rotation and translational motion of [P-122i4] cation at elevated temperatures, whilst leaving that of the [PF6] anion less affected M. F. thanks the Ikerbasque foundation for a visiting professorial fellowship. The authors acknowledge the Australian Research Council for funding through CE140100012. Deakin University's advanced characterisation facility is acknowledged for use of the NMR instruments, funded through the ARC grant LE110100141. J. M. thanks MCIU for the Ramon y Cajal contract and the grant Ref. PGC2018-094620-A-I00. Authors would like to thank the financial support provided by the IONBIKE RISE project. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 823989

Available experimental studies on the effect of the interfacial transition zone (ITZ) on transport properties of cement-based composite materials appear to be ambiguous. The main objective of this work was to enhance the understanding of the relationship between ITZ and transport properties of Portland cement-based materials by using both a rapid chloride migration test and theoretical calculations. A densification factor which is related to aggregate volume content was introduced to further determine the transport properties of ITZ. Results indicate that the overall porosity decreased with increasing aggregate volume content due to the dilution effect by impermeable aggregates. The porosity was above the theoretical dilution line obtained from P0×(1-Vagg) for mortars with more than 20% of aggregate, which can be attributed to the presence of high porous ITZ. On the other hand, more porous ITZ was expected to be accompanied by a denser bulk cement matrix, which leaded to a decrease in the porosity of mortar with less than 35% of aggregate. The ITZ effect would dominate the blocking aggregate, densification and tortuosity of bulk paste when aggregate volume content exceeded 0.35. The ratio between the migration coefficient of the ITZ and that of the matrix (DITZ/Dmatrix) increased with aggregate volume content and assumed ITZ thickness. In addition, the influence of ITZ increased with increasing the degree of interconnection slightly until 1.0. Beyond this value, a sudden increase in DITZ/Dmatrix ratio was observed indicating the negative percolation effect when the adjacent ITZ start to interconnect.

Extensive studies have been reported on the development of service-life prediction of reinforced concrete structures in the last two decades. Service life of a reinforced concrete structure is dependent on the corrosion process, specifically chloride threshold value. Chloride threshold value is a distinctive property and is dependent on several factors such as the supplementary cementitious material used, presence of surface cracks, water to binder ratio, type of steel reinforcement, exposure conditions, measurement methods, etc. Although chloride threshold value is an influential parameter in service-life prediction, a definitive chloride threshold value considering these factors is not reported in the existing literature and standards. Moreover, values adopted in many analytical tools for service life predictions based on the type of steel reinforcement alone are not appropriate and leads to inaccurate calculations. There is a gap in the available literature in understanding the selection of suitable chloride threshold values to be adopted for a specific system. Therefore, it is imperative to study the variation of chloride threshold value with exposure conditions as well as other influencing parameters, to achieve proper service life prediction. In the paper, several influencing parameters on chloride threshold value and its significance on prediction method are comprehensively reviewed. Moreover, suitable recommendations are highlighted for Indian and international standards at the later part of the study.

The gas diffusion coefficient (D-s,D-g) and solute diffusion coefficient (D-s,D-l) and their dependencies on fluid content (kappa) (equal to soil-air content theta for D-s,D-g and soil-water content epsilon for D-s,D-l) are controlling factors for gas and solute transport in variably saturated soils. In this study, we propose unified, predictive models for D-s,D-g(epsilon) and D-s,D-l(theta) based on modifying and extending the classical Maxwell model at fluid saturation with a fluid-induced reduction term including a percolation threshold (epsilon(th) for D-s,D-g and theta(th) for D-s,D-l). Different percolation threshold terms adopted from recent studies for gas (D-s,D-g) and solute (D-s,D-l) diffusion were applied. For gas diffusion, epsilon(th) was a function of bulk density (total porosity), while for solute diffusion theta(th) was best described by volumetric content of finer soil particles (clay and organic matter), FINESvol. The resulting LIquid and GAs diffusivity and tortuosity (LIGA) models were tested against D-s,D-g and D-s,D-l data for differently-textured soils and performed well against the measured data across soil types. A sensitivity analysis using the new Maxwell's Law based LIGA models implied that the liquid phase but not the gaseous-phase tortuosity was controlled by soil type. The analyses also suggested very different pathways and fluid-phase connectivity for gas and solute diffusion in unsaturated soil

International audience; Cobalt-free AB5-type hydrogen storage alloys have been examined for the purpose of lowering metal hydride raw material costs. For this purpose, the electrochemical behaviour of cobalt-free LaNi3.55Mn0.4Al0.3Fe0.75 alloy was investigated using chronopotentiometry and electrochemical impedance spectroscopy. It was shown that the discharge capacity decreases by 50% after fifty cycles. To investigate the capacity decrease, the impedance measurements were conducted during charging at different stages of life cycle. The experimental impedance spectroscopy reveals that the metal hydride electrode exhibits a porous behaviour. The results were then analyzed on the basis of equivalent circuit model involving the porous electrode behaviour according to de Levie's model, i.e. equivalent cylindrical pores connected in parallel. The pore texture of electrode material was then estimated namely by the pore number, mean values of cylinder radius and effective length. The loss of discharge capacity is due to that of the reactivity of the electrode material and not the collapsing of pore texture.

This paper develops a nonparametric model of interest rate term structure dynamics based an a spot rate process that permits only positive interest rates and a market price of interest rate risk that precludes arbitrage opportunities. Both the spot rate process and the market price of interest rate risk are nonparametrically specified so that the model allows for maximal flexibility in fitting into the data. Marginal density of interest rates and historical term structure data are exploited to provide robust estimation of the nonparametric term structure model. The model is implemented using U.S. data, and the estimation results are compared to those in the available literature. Empirical results not only provide strong evidence that most traditional spot rate models and market prices of interest rate risk are misspecified, but also confirm that the nonparametric model generates significantly different term structures and prices of common derivatives.

Novel carbon films with different graphene layer orientations are investigated as electrode materials for Li-ion batteries. It is demonstrated that engineering the crystallographic orientation with graphene layers oriented perpendicular to the surface substantially alters stress evolution during Li insertion. With this crystallographic orientation the intercalating/de-intercalating Li-ions also have direct access to the graphene interlayer spaces, resulting in higher capacity at faster electrochemical cycling, compared to carbon films with graphene layers parallel to the film surface. Electrodes with perpendicular alignment are prepared by supramolecular synthesis using either spin coating or bar coating of chromonic liquid crystal precursors into precursor organic films followed by in situ carbonization. These materials are compared with in situ stress measurements during lithiation/delithiation cycles, and the bar-coated films exhibit a highly anisotropic stress which is consistent with long-range alignment of the graphene layers. In contrast, the in-plane stresses in the spin-coated films are isotropic, which is consistent with the presence of randomly oriented domains (still with graphene layers oriented perpendicular to the surface). Overall, the use of thin film graphitic materials with controlled crystallographic orientations provides a valuable platform for investigating the impact of graphene structure on the properties of Li-ion battery electrode materials.

The transport of small ligands to active sites of proteins is the basis of vital processes in biology such as enzymatic catalysis and cell signaling, but also of more destructive ones including enzyme inhibition and oxidative damage. Here, we show how a diffusion-reaction model solved by means of molecular dynamics and density functional theory calculations provides novel insight into the transport of small ligands in proteins. In particular, we unravel the existence of an elusive, dynamically formed gas channel, which CO2 takes to diffuse from the solvent to the active site (C-cluster) of the bifunctional multisubunit enzyme complex carbon monoxide dehydrogenase/acetyl-CoA synthase (CODH/ACS). Two cavities forming this channel are temporarily created by protein fluctuations and are not apparent in the X-ray structures. The ligand transport is controlled by two residues at the end of this tunnel, His113 and His116, and occurs on the same time scale on which chemical binding to the active site takes place (0.1-1 ms), resulting in an overall binding rate on the second time scale. We find that upon reduction of CO2 to CO, the newly formed Fe-hydroxy ligand greatly strengthens the hydrogen-bond network, preventing CO from exiting the protein through the same way that CO2 takes to enter the protein. This is the basis for directional transport of CO from the production site (C-cluster of CODH subunit) to the utilization site (A-cluster of ACS subunit). In view of these results, a general picture emerges of how large proteins guide small ligands toward their active sites.

Soil thermal conductivity (λ) and heat capacity ( C ) control heat transport and the thermal environment for biogeophysical processes in the vadose zone. Accurate λ and C predictions for peaty soils with high organic contents are particularly important for assessing emissions of greenhouse gases formed during microbial activity in wetlands. In this study, we measured the λ and C at different soil-water matric potentials on undisturbed samples for three peaty soil profiles at the Hokkaido Bibai marsh in Japan, representing a total of 10 different soil horizons. The thermal properties under air-dried conditions, λ dry and C dry , were measured separately at changing volumetric solids contents (σ). For each sample, volume shrinkage was observed to varying degrees during the drying process. Measured λ and C increased linearly with increasing volumetric water content (θ). Applying the concept of a three-phase mixing model and incorporating the λ–θ or C –θ and the λ dry –σ or C dry –σ relations, predictive λ and C models were developed as functions of σ and θ . The new mixing model is represented by λ = λ dry + f λ θλ w and C = C dry + f C θC w , where λ w and C w are the thermal conductivity and heat capacity of water, respectively, and f is an impedance factor that takes into account the liquid-phase tortuosity. The new mixing model predicted literature λ–θ data on peaty and highly organic soils under variable saturation well. The probable ranges of λ and C under variable saturation were proposed based on the sensitivity analysis.

Positively charged polybasic domains are essential for recruiting multiple signaling proteins, such as Ras GTPases and Src kinase, to the negatively charged cellular membranes. Much less, however, is known about the influence of electrostatic interactions on the lateral dynamics of these proteins. We developed a dynamic Monte-Carlo automaton that faithfully simulates lateral diffusion of the adsorbed positively charged oligopeptides as well as the dynamics of mono- (phosphatidylserine) and polyvalent (PIP2) anionic lipids within the bilayer. In agreement with earlier results, our simulations reveal lipid demixing that leads to the formation of a lipid shell associated with the peptide. The computed association times and average numbers of bound lipids demonstrate that tetravalent PIP2 interacts with the peptide much more strongly than monovalent lipid. On the spatially homogeneous membrane, the lipid shell affects the behavior of the peptide only by weakly reducing its lateral mobility. However, spatially heterogeneous distributions of monovalent lipids are found to produce peptide drift, the velocity of which is determined by the total charge of the peptide-lipid complex. We hypothesize that this predicted phenomenon may affect the spatial distribution of proteins with polybasic domains in the context of cell-signaling events that alter the local density of monovalent anionic lipids.

Water content and hydraulic conductivity, including transport within cells, over membranes, cell-to-cell, and long-distance xylem and phloem transport, are strongly affected by plant water stress. By being able to measure these transport processes non-invasely in the intact plant situation in relation to the plant (cell) water balance, it will be possible explicitly or implicitly to examine many aspects of plant function, plant performance, and stress responses. Nuclear magnetic resonance imaging (MRI) techniques are now available that allow studying plant hydraulics on different length scales within intact plants. The information within MRI images can be manipulated in such a way that cell compartment size, water membrane permeability, water cell-to-cell transport, and xylem and phloem flow hydraulics are obtained in addition to anatomical information. These techniques are non-destructive and non-invasive and can be used to study the dynamics of plant water relations and water transport, for example, as a function of environmental (stress) conditions. An overview of NMR and MRI methods to measure such information is presented and hardware solutions for minimal invasive intact plant MRI are discussed.

We report definitive evidence for an effective interfacial tension between two types of miscible fluids using spinning-drop tensiometry (SDT). Isobutyric acid (IBA) and water have an upper critical solution temperature (UCST) of 26.3 degrees C. We created a drop of the IBA-rich phase in the water-rich phase below the UCST and then increased the temperature above it. Long after the fluids have reached thermal equilibrium, the drop persists. By plotting the inverse of the drop radius cubed (r(-)(3)) vs the rotation rate squared (omega(2)), we confirmed that an interfacial tension exists and estimated its value. The transition between the miscible fluids remained sharp instead of becoming more diffuse, and the drop volume decreased with time. We observed droplet breakup via the Rayleigh-Tomotika instability above the UCST when the rotation rate was decreased by 80%, again demonstrating the existence of an effective interfacial tension. When pure IBA was injected into water above the UCST, drops formed inside the main drop even as the main drop decreased in volume with time. We also studied 1-butanol in water below the solubility limit. Effective interfacial tension values measured over time were practically constant, while the interface between the two phases remains sharp as the volume of the drop declines. The effective interfacial tension was found to be insensitive to changes in temperature and always larger than the equilibrium interfacial tension. Although these results may not apply to all miscible fluids, they clearly show that an effective interfacial tension can exist and be measured by SDT for some systems.

This paper develops a nonparametric model of interest rate term structure dynamics based an a spot rate process that permits only positive interest rates and a market price of interest rate risk that precludes arbitrage opportunities. Both the spot rate process and the market price of interest rate risk are nonparametrically specified so that the model allows for maximal flexibility in fitting into the data. Marginal density of interest rates and historical term structure data are exploited to provide robust estimation of the nonparametric term structure model. The model is implemented using U.S. data, and the estimation results are compared to those in the available literature. Empirical results not only provide strong evidence that most traditional spot rate models and market prices of interest rate risk are misspecified, but also confirm that the nonparametric model generates significantly different term structures and prices of common derivatives.

This paper develops a nonparametric model of interest rate term structure dynamics based on a spot rate process that permits only positive interest rates and a market price of interest rate risk that precludes arbitrage opportunities. Both the spot rate process and the mar? ket price of interest rate risk are nonparametrically specified so that the model allows for maximal flexibility in fitting into the data. Marginal density of interest rates and historical term structure data are exploited to provide robust estimation of the nonparametric term structure model. The model is implemented using U.S. data, and the estimation results are compared to those in the available literature. Empirical results not only provide strong evidence that most traditional spot rate models and market prices of interest rate risk are misspecified, but also confirm that the nonparametric model generates significantly differ? ent term structures and prices of common derivatives.

Inverse-Fluorescence Correlation Spectroscopy (iFCS) is a recently developed modification of standard FCS that allows analysis of particles and biomolecules without labeling. The particles generate no signal; instead the signal is generated by a surrounding medium. Particles diffusing through the FCS-detection volume displace a fraction of the surrounding medium, causing transient dips in the detected signal. These give information about the mobility and concentration of the analyzed particles. Also labeled particles can be analyzed, whereby their signal is cross-correlated with that from the surrounding medium (iFCCS). This can give information about the volume of the labeled particles, or alternatively about the size of the detection volume. Also the interaction of unlabeled particles with small, labeled ligands can be analyzed with iFCCS. This allows using cross-correlation as a sensitive indication of binding, even though only one binding-partner is labeled. This review describes the principles of iFCS and iFCCS and measurements of microspheres dissolved in a surrounding medium containing alexa 488. We also discuss practical considerations, and future possibilities for analyses of biomolecules.

An improved 3-D Monte Carlo simulation model is developed to treat the discrete random dopant distribution in sub-0.1 μm MOSFET. The new atomistic model is based on a scattering rate calculation and an algorithm that take into account many-body effects and the local variations of screening length according to impurity distribution and bias conditions.To validate this new approach low field electron drift mobility and diffusion coefficient have been computed using simulation of 3D bars for 1015–1018 cm–3 range of average doping concentration. A good agreement is found between calculation and experimental mobility data at 300 K.