Large Morphological Changes Research Articles

Review on Artificial Interphases for Lithium Metal Anodes: From a Mechanical Perspective

AbstractLithium (Li) metal is a promising candidate for next‐generation high‐energy‐density rechargeable batteries. However, the solid electrolyte interphase (SEI) inevitably suffers from mechanical fracture owing to the large morphological change during Li cycling, leading to the uncontrollable growth of Li dendrites, low Coulombic efficiency, and short cycle life. The fabrication of an artificial interphase is an effective strategy for improving the performances of Li metal anodes. The ideal artificial interphase should provide sufficient mechanical robustness to suppress dendritic Li growth and accommodate large volume changes during Li deposition‐dissolution cycles. In this review, we focus on the fabrication of mechanically robust artificial interphases for stabilizing Li‐metal anodes, including the underlying mechanism of SEI fracture, quantitative requirements for mechanical properties, measurements of mechanical properties, and recent progress in the fabrication of mechanically stable artificial interphases.

Quantifying earthworm soil ingestion from changes in vertical bulk density profiles

Soil mixing by earthworms can have a large impact on the fate of nutrients and pollutants and on the soil's ability to sequester carbon. Nevertheless, methods to quantify earthworm ingestion and egestion under field conditions are largely lacking. Soils of the Fennoscandian tundra offer a special possibility for such quantifications, as these soils commonly lack burrowing macrofauna and exhibit a well-defined O horizon with low bulk density on top of a mineral soil with higher density. Since ingestion-egestion mixes the two soil layers, the temporal changes in the bulk density profile of such soils may be useful for estimating field ingestion rates. In this study, we applied a model for earthworm burrowing through soil ingestion to observed changes in soil densities occurring in a mesocosm experiment carried out in the arctic during four summers with intact soil. The earthworms present in the mesocosms were Aporrectodea trapezoides, Aporrectodea tuberculata, Aporrectodea rosea, Lumbricus rubellus and Lumbricus Terrestris (fourth season only). We show that changes in soil density profiles can indeed be used to infer earthworm ingestion rates that are realistic in comparison to literature values. Although uncertainties in parameter values were sometimes large, the results from this study suggest that soil turnover rates and endogeic earthworm soil ingestion rates in tundra heath and meadow soils may be as high as those reported for temperate conditions. Such large ingestion rates can explain observed large morphological changes in arctic soils where dispersing earthworms have resulted in complete inmixing of the organic layer into the mineral soil. Our approach is applicable to soil profiles with marked vertical differences in bulk density such as the soils of the Fennoscandian tundra where earthworms are currently dispersing into new areas and to layered repacked soil samples that are incubated in the field.

The VBNC state: a fundamental survival strategy of Acinetobacter baumannii.

Currently, the viable but non-culturable (VBNC) state is an underappreciated niche for pathogenic bacteria which provides a continuous source for recurrent infections and transmission. We propose the VBNC state to be a global persistence mechanism used by various A. baumannii strains to cope with many stresses it is confronted with in the clinical environment and in the host. This requires a novel strategy to detect viable cells of this pathogen that is not only based on plating assays.

Factors Controlling Complex Morphologies of Isomorphous Metal-Organic Frameworks.

We demonstrate here how nitrate salts of bivalent copper, nickel, cobalt, and manganese, along with an achiral organic ligand, assemble into various structures such as symmetrical double-decker flowers, smooth elongated hexagonal bipyramids, and hexagonal prisms. Large morphological changes occur in these structures because of different metal cations, although they maintain isomorphous hexagonal crystallographic structures. Metal cations with stronger coordination to ligands (Cu and Ni) tend to form uniform crystals with unusual shapes, whereas weaker coordinating metal cations (Mn and Co) produce crystals with more regular hexagonal morphologies. The unusual flower-like crystals formed with copper nitrate have two pairs of six symmetrical petals with hexagonal convex centers. The texture of the petals indicates dendritic growth. Two different types of morphologies were formed by using different copper nitrate-to-ligand ratios. An excess of the metal salt results in uniform and hexagonal crystals having a narrow size distribution, whereas the use of an excess of ligand results in double-decker morphologies. Mechanistically, an intermediate structure was observed with slightly concave facets and a domed center. Such structures most likely play a key role in the formation of double-decker crystals that can be formed by fusion processes. The coordination chemistry results in isostructural chiral frameworks consisting of two types of continuous helical channels. Four pyridine units from four separate ligands are coordinated to the metal center in a plane having a chiral (propeller-type) arrangement. The individual double-decker flower crystals are homochiral and a batch consists of crystals having both handedness.

Bistable reconfigurable origami metamaterials with high load-bearing and low state-switching forces

Bistable shape-reconfigurable metamaterials can achieve large morphological changes under a relatively low state-switching force and can maintain the configuration autonomously after removing the force. However, the state-switching force and the load-bearing forces are usually coupled in the same direction, resulting in low loadability at the deployed state. Here we separate the load-bearing direction and the state-switching direction of bistable unit, and combine the directional folding feature of origami to design a shape-reconfigurable metamaterial with high bearing force and low switching force, named mechanical relay metamaterial. The feasibility of the design concept is first validated experimentally. The bearing force of the mechanical relay metamaterial is at least 4 times the switching force and 100 times the gravity of self-weight. Then the geometric design domain of the unit is derived by spherical trigonometry. Finally, the effect of geometric parameters on the load carrying capacity of the unit is investigated by finite element simulations, and the optimal geometric parameters are determined. This work provides an effective solution for bistable shape-reconfigurable metamaterials with high bearing force and low switching force.

Diversification of cephalic shield shape and antenna in phyllosoma I of slipper and spiny lobsters (Decapoda: Achelata)

Slipper (Scyllaridae) and spiny (Palinuridae) lobsters show a complex life cycle with a planktonic larval phase, named phyllosoma. This unique larval form within Achelata (Decapoda) is characterized by a transparent dorsoventrally compressed body and a pair of antennae. This conspicuous morphology has been attributed to adaptive specialization of planktonic life. Early studies suggest that phyllosoma morphology has remained constant over the evolutionary history of Achelata, while recent evidence points out large morphological changes and that diversification of phyllosoma larvae is a consequence of radiation and specialization processes to exploit different habitats. Given the ecological and evolutive significance of phyllosoma, we used shape variation of the first phyllosoma stage (phyllosoma I) and a time-calibrated phylogeny of extant Achelata to study how diversification of phyllosoma I shape occurred along with the evolutionary history of Achelata. Our results show a conserved phyllosoma I with a pear-shaped cephalic shield and large antennae in spiny lobsters and older groups of slipper lobsters, yet highly specialized phyllosoma I with wide rounded cephalic shield and short antennae in younger groups of slipper lobsters. Analyses revealed two bursts of lineage diversification in mid and late history without a slowdown in recent times. Both bursts preceded large bursts of morphological disparity. These results joined with the allopatric distribution of species and convergence of phyllosoma I shapes between largely divergent groups suggest that diversification involves nonadaptive radiation processes. However, the correlation of a major direction of shape with the maximum distribution depth of adults and the occurrence of the second burst of diversification post-extinction of competitors within Achelata presuppose some ecological opportunities that might have promoted lineage and morphological diversification, fitting to the characteristic components of adaptive radiations. Therefore, we conclude that diversification of Achelata presents a main signature of nonadaptive radiation with some components of adaptive radiation.

DGKα, Bridging Membrane Shape Changes with Specific Molecular Species of DAG/PA: Implications in Cancer and Immunosurveillance.

Cancer immunotherapy has revolutionized the oncology field. Despite the success, new molecular targets are needed to increase the percentage of patients that benefits from this therapy. Diacylglycerol kinase α (DGKα) has gathered great attention as a potential molecular target in immunotherapy because of its role in cancer proliferation and immunosuppression. DGKα catalyzes the ATP-dependent phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PA). Since both lipids are potent signaling messengers, DGKα acts as a switch between different signaling pathways. Its role in cancer and immunosuppression has long been ascribed to the regulation of DAG/PA levels. However, this paradigm has been challenged with the identification of DGKα substrate acyl chain specificity, which suggests its role in signaling could be specific to DAG/PA molecular species. In several biological processes where DGKα plays a role, large membrane morphological changes take place. DGKα substrate specificity depends on the shape of the membrane that the enzyme binds to. Hence, DGKα can act as a bridge between large membrane morphological changes and the regulation of specific molecular species of DAG/PA. Bearing in mind the potential therapeutic benefits of targeting DGKα, here, the role of DGKα in cancer and T cell biology with a focus on the modulation of its enzymatic properties by membrane shape is reviewed. The goal is to contribute to a global understanding of the molecular mechanisms governing DGKα biology. This will pave the way for future experimentation and, consequently, the design of better, more potent therapeutic strategies aiming at improving the health outcomes of cancer patients.

Examination of New Indicators in Adaptive Radiotherapy Using Machine Learning in Head and Neck Volumetric Modulated Arc Therapy

<h3>Purpose/Objective(s)</h3> During head and neck intensity-modulated radiotherapy treatment, a decrease in the patient's bodyweight and tumor size can often lead to inconsistencies in fixation and over- or under-dosage around the target. Treatment accuracy can be ensured by image-guided radiotherapy (IGRT). If substantial changes occur in the tumor volume or bodyweight, adaptive radiotherapy (ART) is performed. There is no clear guideline to initiate ART, and the decision is largely operator-driven. This study aimed to propose a new ART index using cone-beam computed tomography (CBCT) for existing patient data using machine learning. <h3>Materials/Methods</h3> The clinical target volume (CTV) and the parotid glands on the planning CT were automatically contoured to CBCT by deformable image registration (DIR), and the dice similarity coefficient (DSC) according to the number of fractions that were calculated from the original ROIs and DIR_ROIs. These DSCs were normalized by the maximum value and differentiated between patients who underwent ART (n = 416) and those who did not (n = 704). To determine the ART trigger from these DSCs, we devised a program that could guide the decision boundary by machine learning. The decision boundary was calculated using Python 3.7.6 with a support vector machine (SVM). T-test was performed to observe whether there was a difference in the slopes of the CTV and the parotid glands with and without replanning. We included the difference due to the slopes to the decision boundary and examined whether it is possible to classify areas as requiring ART or not. <h3>Results</h3> The accuracy rate using the test data was 0.66 for SVM. The decision boundary was shown by the following equation, where f(x) is the DSC and x is the number of fractions. f(x) = -0.0087x + 0.814 The p-values of the ART group and the non-implemented group of the slopes of CTV and the parotid glands were 0.005 and 4.195E-17, respectively, and a significant difference was confirmed (p < 0.05). Normal distribution was created from the slopes of each unimplemented group. The correct answer rate increased to 0.75, assuming that the slope larger than 1σ was an additional condition for ART. <h3>Conclusion</h3> We were able to derive the decision boundary f(x) using machine learning. If the DSC shows a value lower than the f(x) calculated for the same number of fractions, ART is indicated. However, in some cases, ART was performed even though it was not numerically necessary. In other cases, patients who did not undergo ART were judged numerically to require ART. These may be due to the DIR not working well because the tumor changes were intracranial, or due to the oncologist's preference not to perform ART despite large morphological changes. In this study, we proposed the need for ART to approximately 75% of patients. The findings suggest that machine learning may assist the operator with decision-making and replanning.

Transient regulation of focal adhesion via Tensin3 is required for nascent oligodendrocyte differentiation.

The differentiation of oligodendroglia from oligodendrocyte precursor cells (OPCs) to complex and extensive myelinating oligodendrocytes (OLs) is a multistep process that involves large-scale morphological changes with significant strain on the cytoskeleton. While key chromatin and transcriptional regulators of differentiation have been identified, their target genes responsible for the morphological changes occurring during OL myelination are still largely unknown. Here, we show that the regulator of focal adhesion, Tensin3 (Tns3), is a direct target gene of Olig2, Chd7, and Chd8, transcriptional regulators of OL differentiation. Tns3 is transiently upregulated and localized to cell processes of immature OLs, together with integrin-β1, a key mediator of survival at this transient stage. Constitutive &lt;i&gt;Tns3&lt;/i&gt; loss of function leads to reduced viability in mouse and humans, with surviving knockout mice still expressing Tns3 in oligodendroglia. Acute deletion of &lt;i&gt;Tns3&lt;/i&gt; in vivo, either in postnatal neural stem cells (NSCs) or in OPCs, leads to a twofold reduction in OL numbers. We find that the transient upregulation of Tns3 is required to protect differentiating OPCs and immature OLs from cell death by preventing the upregulation of p53, a key regulator of apoptosis. Altogether, our findings reveal a specific time window during which transcriptional upregulation of Tns3 in immature OLs is required for OL differentiation likely by mediating integrin-β1 survival signaling to the actin cytoskeleton as OL undergo the large morphological changes required for their terminal differentiation.

A NURBS-based inverse analysis of swelling induced morphing of thin stimuli-responsive polymer gels

Gels are a mixture of cross-linked polymers and solvents, and have been widely studied in recent years for a diverse range of biomedical applications. Because gels can undergo large, reversible shape changes due to swelling, their complex physical response must be modeled by coupling large reversible deformation and mass transport. An ongoing challenge in this field is the ability to capture swelling or residual swelling-induced of such stimuli-responsive gels from initially flat two-dimensional (2D) to three-dimensional (3D) curved shapes. Specifically, because such shape changes typically involve large deformations, shape changes, and the exploitation of elastic instabilities, it remains an open question as to what external stimulus should be prescribed to generate a specific target shape. Therefore, we propose a novel formulation that tackles, using both nonlinear kinematics and material models, the coupling between elasticity and solvent transport using Kirchhoff–Love shell theory discretized using isogeometric analysis (IGA). Second, we propose an inverse methodology that chemomechanically couples large deformation and mass transport to identify the external stimuli prescribed to generate a specific target shape. Our numerical examples demonstrate the capability of identifying the required external stimuli, with the implication that the reconstructed target shapes are accurate, including cases where the shape changes due to swelling involve elastic instabilities or softening. Overall, our study can be used to effectively predict and control the large morphological changes of an important class of stimuli-responsive materials.

Large wood mobilization and morphological changes in an alpine river following the release of an ordinary experimental flood from an upstream dam

The work documents morphological changes and large wood (LW) mobilization in a river-reach located downstream of a dam along the Spöl River (Switzerland), following an 8 h experimental release of 1.2-year flood. The aim of the flood was to mimic a natural event able to wash out either or both the sediment and LW. Two field campaigns (before and after the event) were made to generate DEMs and to collect data concerning the river morphology and LW characteristics. The formers were used to produce a Dem Of Difference (DoD) while the latter to identify the LW load fluctuations. Statistical analyses were implemented taking advantage of a 2D flowing model software (HEC-RAS 5.0.7) in order to compute the dimensionless diameter (D* = Flow depth (m)/ LW diameter (m)) and to detect, along with analysis of resident and mobile groups of wood, a mobility threshold (D* = 2.77) by means of a binary regression model (60 % accuracy). The threshold was used to estimate different mobility rates according to different water discharge scenarios. Overall, the event produced slight widespread morphological changes all over the channel, with a modest sediment deposition (2341 m3). Although evidence of LW fluctuations was detected, the LW input and output were almost equal (3.6 m3 ha−1 and 3.9 m3 ha−1, respectively) generating a net difference of – 0.79 m3. The median of the mobile LW was considerably lower compared to that of the resident LW. The results obtained demonstrated that the original aim of the experimental flood, to transport out wood and sediment, was not achieved because the duration and magnitude of such type of flood was limited, inducing equilibrium in the LW load and generating only slight morphological changes.

Contrasting Common Era climate and hydrology sensitivities from paired lake sediment dinosterol hydrogen isotope records in the South Pacific Convergence Zone

Hydroclimate on ‘Uvea (Wallis et Futuna) is controlled by rainfall associated with the South Pacific Convergence Zone (SPCZ), the southern hemisphere's largest precipitation feature. To extend the short observational precipitation record, the hydrogen isotopic composition of the algal lipid biomarker dinosterol (δ2Hdinosterol) was measured in sediment cores from two volcanic crater lakes on ‘Uvea. The modern lakes differ morphologically and chemically but both contain freshwater within the photic zone, support phytoplankton communities inclusive of dinosterol-producing dinoflagellates, and experience identical climate conditions. δ2Hdinosterol values track lake water isotope ratios, ultimately controlled in the tropics by precipitation amount and evaporative enrichment. However, in 88-m-deep Lac Lalolalo a steadily decreasing trend in sedimentary δ2Hdinosterol values from −227‰ around year 988 CE to modern values as low as −303‰, suggests this lake's evolution from an active volcanic setting to the present system strongly influenced δ2Hdinosterol values. Although current hydrology and water isotope systematics may now reflect precipitation and evaporation in this lake, the interaction between these processes and large changes in basin morphology, geochemistry, and hydrology obstruct the recovery of a climate signal from Lac Lalolalo's sedimentary δ2Hdinosterol records. This work emphasizes the importance of site replication and the use of complementary climate reconstruction tools, especially when using molecular proxies that may be sensitive to more than one environmental parameter. Contrary to its neighbor, duplicate δ2Hdinosterol records from 23-m-deep Lac Lanutavake varied between −277‰ and −297‰ and indicate slightly drier conditions during the time-period known as the Medieval Climate Anomaly (MCA, 950–1250 CE). The δ2Hdinosterol signal in Lac Lanutavake was muted compared to published records from ‘Upolu (Samoa) and Efate (Vanuatu) indicating that ‘Uvea's location is not as sensitive to precipitation variability at sites farther from the SPCZ central axis. Lithogenic runoff proxies combined with δ2Hdinosterol support the interpretation of a relatively dry MCA on ‘Uvea, ‘Upolu, and Efate, potentially due to less intense precipitation, a contracted, or a more zonally oriented SPCZ.

Microwave-Enabled Size Control of Iron Oxide Nanoparticles on Reduced Graphene Oxide

Nanoparticle-functionalized 2D material networks are promising for a wide range of applications, but in situ formation of nanoparticles is commonly challenged by rapid growth. Here, we demonstrate controlled synthesis of small and dispersed iron oxide nanoparticles on reduced graphene oxide (rGO) networks through rapid localized heating with microwaves with low-cost iron nitrate as the precursor. The strong coupling of the microwave radiation with the rGO network rapidly heats the network locally to decompose the iron nitrate and generate iron oxide nanoparticles, while cessation of microwaves leads to rapid cooling to minimize crystal growth. Small changes in the microwave reaction time (<1 min) led to very large changes in the iron oxide morphology. The solid-state microwave syntheses produced narrower nanoparticle size distribution than conventional heating. These results illustrate the potential of solid-state microwave syntheses to control the nanoparticle size on 2D materials through rapid localized heating under the microwave process conditions, which should be extendable to a variety of transition metal oxide-rGO systems.

Placental Findings in Preterm and Term Preeclampsia: An Integrative Review of the Literature.

Preeclampsia (PE) is a pregnancy complication associated with increased maternal and perinatal morbidity and mortality. The disease presents with recent onset hypertension (after 20 weeks of gestation) and proteinuria, and can progress to multiple organ dysfunction, with worse outcomes among early onset preeclampsia (EOP) cases (< 34 weeks). The placenta is considered the root cause of PE; it represents the interface between the mother and the fetus, and acts as a macromembrane between the two circulations, due to its villous and vascular structures. Therefore, in pathological conditions, macroscopic and microscopic evaluation can provide clinically useful information that can confirm diagnosis and enlighten about outcomes and future therapeutic benefit. To perform an integrative review of the literature on pathological placental findings associated to preeclampsia (comparing EOP and late onset preeclampsia [LOP]) and its impacts on clinical manifestations. Cases of EOP presented worse maternal and perinatal outcomes, and pathophysiological and anatomopathological findings were different between EOP and LOP placentas, with less placental perfusion, greater placental pathological changes with less villous volume (villous hypoplasia), greater amount of trophoblastic debris, syncytial nodules, microcalcification, villous infarcts, decidual arteriolopathy in EOP placentas when compared with LOP placentas. Clinically, the use of low doses of aspirin has been shown to be effective in preventing PE, as well as magnesium sulfate in preventing seizures in cases of severe features. The anatomopathological characteristics between EOP and LOP are significantly different, with large morphological changes in cases of EOP, such as hypoxia, villous infarctions, and hypoplasia, among others, most likely as an attempt to ascertain adequate blood flow to the fetus. Therefore, a better understanding of the basic macroscopic examination and histological patterns of the injury is important to help justify outcomes and to determine cases more prone to recurrence and long-term consequences.

Morphodynamic modeling of a low-lying barrier subject to hurricane forcing: The role of backbarrier wetlands

Along much of the world's coastline, coastal barriers serve as the first line of defense against oceanic and meteorological forces. Extreme storms cause large morphological changes on coastal barriers through high sediment transport rates, which may degrade their defensive capabilities. The understanding of morphological impacts is therefore important for coastal resiliency, but is often challenged by site-specific characteristics, such as land cover and sediment availability, and their poorly understood impacts on the governing physical processes. The Caminada Headlands, Louisiana, USA presents unique considerations for morphodynamic modeling with regard to its low-lying topography, variable land cover, nearshore muddy substrate and sand deficiency. This study investigates the effects of land cover and limited sediment supply on low-lying barrier island morphology under storm conditions by using physics-based numerical models. A high-resolution, local-scale sediment transport/morphodynamic model (XBeach) of the Caminada Headlands is verified for Hurricane Gustav's (2008) impact using pre- and post-storm LIDAR surveys. When accurate input data are used to create physics-based numerical models these tools are robust in hindcasting storm impacts and provide a wealth of information as to the governing processes, which is otherwise difficult to obtain observationally. The simulation results show that a short-duration overwash regime dominates the morphological change in this low-lying barrier and is influenced by backbarrier wetland deterioration. The morphological response to overwash is modulated by backbarrier land cover and topography, as reduced accommodation space limits landward transport during the subsequent inundation regime. An intact backbarrier marsh reduces landward washover sediment transport distances and promotes deposition at supratidal elevations. In light of these findings, simultaneous restoration/creation of backbarrier wetlands in conjunction with subaerial beach renourishment may be an effective form of increasing the resiliency of low-lying barriers subject to frequent overwashing.

Microglia and astrocytes show limited, acute alterations in morphology and protein expression following a single developmental alcohol exposure.

Fetal alcohol spectrum disorders (FASD) are the most common cause of nonheritable, preventable mental disability and are characterized by cognitive, behavioral, and physical impairments. FASD occurs in almost 5% of births in the United States, but despite this prevalence there is no known cure, largely because the biological mechanisms that translate alcohol exposure to neuropathology are not well understood. While the effects of early ethanol exposure on neuronal survival and circuitry have received more attention, glia, the cells most closely tied to initiating and propagating inflammatory events, could be an important target for alcohol in the developing brain. Inflammation is known to alter developmental trajectories, but it has recently been shown that even small changes in both astrocytes and microglia in the absence of full-blown inflammatory signaling can alter brain function long-term. Here, we studied the acute response of astrocytes and microglia to a single exposure to ethanol in development across sexes in a mouse model of human third trimester exposure, in order to understand how these cells may transition from their normal developmental path to a different program that leads to FASD neuropathology. We found that although a single ethanol exposure delivered subcutaneously on postnatal day 4 did not cause large changes in microglial morphology or the expression of AldH1L1 and GFAP in the cortex and hippocampus, subtle effects were observed. These findings suggest that even a single, early ethanol exposure can induce mild acute alterations in glia that could contribute to developmental deficits.

The Dynamic Roles of the Inner Membrane Complex in the Multiple Stages of the Malaria Parasite.

Apicomplexan parasites, such as human malaria parasites, have complex lifecycles encompassing multiple and diverse environmental niches. Invading, replicating, and escaping from different cell types, along with exploiting each intracellular niche, necessitate large and dynamic changes in parasite morphology and cellular architecture. The inner membrane complex (IMC) is a unique structural element that is intricately involved with these distinct morphological changes. The IMC is a double membrane organelle that forms de novo and is located beneath the plasma membrane of these single-celled organisms. In Plasmodium spp. parasites it has three major purposes: it confers stability and shape to the cell, functions as an important scaffolding compartment during the formation of daughter cells, and plays a major role in motility and invasion. Recent years have revealed greater insights into the architecture, protein composition and function of the IMC. Here, we discuss the multiple roles of the IMC in each parasite lifecycle stage as well as insights into its sub-compartmentalization, biogenesis, disassembly and regulation during stage conversion of P. falciparum.

Simulating storm waves in the nearshore area using spectral model: Current issues and a pragmatic solution

Short waves are of key importance for nearshore dynamics, particularly under storms, where they contribute to extreme water levels and drive large morphological changes. Therefore, it is crucial to model accurately the propagation and dissipation of storm waves in the nearshore area. In this paper, field observations collected in contrasted environments and conditions are combined with predictions from a third-generation spectral wave model to evaluate four formulations of wave energy dissipation by depth-induced breaking. The results reveal a substantial over-dissipation of incident wave energy occurring over the continental shelf, resulting in a negative bias on significant wave height reaching up to 50%. To overcome this problem, a breaking coefficient dependent of the local bottom slope is introduced within depth-induced breaking models in order to account for the varying degrees of saturation naturally found in breaking and broken waves. This approach strongly reduces the negative bias observed in the shoreface compared to default parameterizations, yielding significant improvements in the prediction of storm waves. Among the implications of this study, our new parameterization of the breaking coefficient results in systematically increased predictions of the wave setup near the shoreline compared to the default parameterization. This increase reaches a factor 2 for gently sloping beaches.

Conducting polymer composites as water-dispersible electrode matrices for Li-Ion batteries: Synthesis and characterization

As battery materials increase in energy density, the likelihood of larger morphological changes during cycling increases. Current PVDF/carbon electrode matrices are ill-prepared for such materials and new battery electrode matrices are required. Typical strategies replace PVDF by aqueous binders, utilize other carbonaceous conductive additives or add small amounts of conducting polymers. In this study, we propose a class of water-processable, self-conductive electrode matrices that relies on the combination of polyelectrolyte binders with conducting polymers. By in situ polymerizing conducting polymer monomers in an aqueous solution of carboxylate-containing polymers, new electrode matrices are synthesized, in which components are intimately mixed at the nano-scale. Herein, the molecular composite polypyrrole:carboxymethyl cellulose (PPy:CMC), as a representative electrode matrix, allows the water-based electrode fabrication of carbon-additive-free electrodes. No additional binders and conductive additives are required to fabricate electrodes due to the adhesive and conductive features of PPy:CMC composites. This study paves the way for developing a promising type of electrode matrices for Li-ion batteries based on conducting polymer molecular composites that are adhesive and conductive, ensuring high-energy-density battery materials maintain active over more cycles. • Water-dispersible, self-conductive binder from low-cost, high-volume raw materials. • Simple synthesis and purification yields nano-composite of polypyrrole and carboxymethyl cellulose. • Binder is compatible with industry-typical slurry casting (tape casting). • Carbon additive-free lithium intercalation cathode operates at 1C.

Shock effects of monovalent cationic salts on seawater cultivated granular sludge

Saline wastewater is commonly encountered in various industries, posing challenges to biological treatments. The application of seawater as a seed source provides a media of diverse halophilic organisms for rapid startup. However, effects of transitioning from a mixed salt source to monovalent salt solutions prevalent in industry remains unexplored. Hence, seed sludge was cultivated using seawater and later granulated under a mixed-salt synthetic medium comprising a mixture of NaCl, KCl and Na2SO4 at a combined concentration of 0.8 M (0.27 M each). The stable, acclimated granules were then tested against single salt media of 0.8 M NaCl, KCl, or Na2SO4. Shift to single salt media resulted in granule disaggregation, poor settling, sludge washout and development of fluffy or slimy flocs. Changes in exopolysaccharides composition after the single salt shift was the predominant reason for the large changes in sludge morphology. The impacts of KCl and Na2SO4 were more significant than the shift to NaCl. The resulting impacts also had a major influence on the treatment performance. A complex mechanism involving monovalent cation stimulation of proteins; ionic strength impacts on exopolysaccharides and morphology; solution density influence on sludge density and settling; and tonicity impacts on cell viability and treatment is described.