Multiscale Structural Analysis Research Articles

Analysis of multiscale structures at the quasi-perpendicular Venus bow shock

Context.Solar Orbiter is a European Space Agency mission with a suite of in situ and remote sensing instruments to investigate the physical processes across the inner heliosphere. During the mission, the spacecraft is expected to perform multiple Venus gravity assist maneuvers while providing measurements of the Venusian plasma environment. The first of these occurred on 27 December 2020, in which the spacecraft measured the regions such as the distant and near Venus magnetotail, magnetosheath, and bow shock.Aims.This study aims to investigate the outbound Venus bow shock crossing measured by Solar Orbiter during the first flyby. We study the complex features of the bow shock traversal in which multiple large amplitude magnetic field and density structures were observed as well as higher frequency waves. Our aim is to understand the physical mechanisms responsible for these high amplitude structures, characterize the higher frequency waves, determine the source of the waves, and put these results into context with terrestrial bow shock observations.Methods.High cadence magnetic field, electric field, and electron density measurements were employed to characterize the properties of the large amplitude structures and identify the relevant physical process. Minimum variance analysis, theoretical shock descriptions, coherency analysis, and singular value decomposition were used to study the properties of the higher frequency waves to compare and identify the wave mode.Results.The non-planar features of the bow shock are consistent with shock rippling and/or large amplitude whistler waves. Higher frequency waves are identified as whistler-mode waves, but their properties across the shock imply they may be generated by electron beams and temperature anisotropies.Conclusions.The Venus bow shock at a moderately high Mach number (∼5) in the quasi-perpendicular regime exhibits complex features similar to the Earth’s bow shock at comparable Mach numbers. The study highlights the need to be able to distinguish between large amplitude waves and spatial structures such as shock rippling. The simultaneous high frequency observations also demonstrate the complex nature of energy dissipation at the shock and the important question of understanding cross-scale coupling in these complex regions. These observations will be important to interpreting future planetary missions and additional gravity assist maneuvers.

Multi-scale structure, rheological and digestive properties of starch isolated from highland barley kernels subjected to different thermal treatments

Thermal treatment has been used to modify starch properties, but few studies pay attention to the change in highland barley starch (HBS) under the whole kernel treatment. The different effect of superheated steam (SS) on the HBS properties from other traditional thermal treatment is still unclear, not mention to the exactly structural change of HBS. This study explored the different effects of SS, steam and roasting treatments of HB kernel on the multi-scale structure, rheological and digestive properties of HBS. Thermal treatments led to the aggregation of HBS granules, the rough surface, and the absence of Maltese cross, as well as the increase in short-chain length ratio and amylose content. Compared with steam and roasting treatments, SS treatment increased the average molecular weight of HBS at 140 °C while reduced it at 180 °C due to starch interactions and depolymerization effect. Multi-scale structure analysis revealed that SS-180 showed the most significant disruption of HBS crystalline structure, the disorder of short-range structure, the decrease in double helix content and the disruption of lamellar structure. These structural changes of HBS resulted in the enhanced thermal stability, and decreased values of G′ and G″ representing the weaker gel structures. Meanwhile, much more resistant starch was converted from rapid digestible starch and slowly digestible starch in SS-treated HB than other thermal-treated HB. In particularly, the most change in multi-scale structure of HBS caused by SS-180 was responsible for its best thermal stability, weakest gel structures and slowest starch digestive rate.

Effect of protein topology on hierarchical complexation of epsilon-polylysine and protein: A multiscale structural analysis

ε-polylysine (EPL) is an antimicrobial peptide. Despite the utilization of EPL as a natural preservative worldwide, it will be deactivated owing to phase separation when it encounters some macroions. Interestingly, previous studies demonstrated the approach to preserve its antimicrobial efficacy by forming another delicate structure, the “soluble” complexes, but their interaction mechanism and structure remain unclear. This work elucidated the hierarchically structural complexation of EPL with three representative proteins β-casein, β-lactoglobulin and bovine serum albumin. It was found that these hierarchical structures separated into compact mesophase dispersions and porous precipitations, and range from nanometers to microns length scales. The driving forces for the association between EPL and protein have been mainly considered as electrostatic and subsequently hydrophobic attractions. Our results illustrated how the differences in topology (spatial structure, charge anisotropy, and hydrophobicity) among various proteins determined the specifically hierarchical structures of EPL-protein complexation. Unfolded protein with the concentrated negative charge and hydrophobicity patches inclined to form aggregation readily, whereas the folded protein with a relative disperses geometry could create the structural forces to form partial steady-state complexes. This work provides a general structural evolution of EPL-protein complexation and paved the way for its future application in food science and biotechnology.

Predicting mechanically driven full-field quantities of interest with deep learning-based metamodels

Using simulation to predict the mechanical behavior of heterogeneous materials has applications ranging from topology optimization to multi-scale structural analysis. However, full-fidelity simulation techniques such as Finite Element Analysis, while effective, can be prohibitively computationally expensive when they are used to explore the massive input parameter space of heterogeneous materials. Therefore, there has been significant recent interest in machine learning-based models that, once trained, can predict mechanical behavior at a fraction of the computational cost compared to full fidelity simulations. Over the past several years, research in this area has been focused mainly on predicting single Quantities of Interest (QoIs). However, there has recently been an increased interest in a more challenging problem: predicting full-field QoI (e.g., displacement/strain fields, damage fields) for mechanical problems. Due to the added complexity of full-field information, network architectures that perform well on single QoI problems may perform relatively poorly in the full-field QoI problem setting. This problem is also challenging because, even outside the Mechanics research community, deep learning approaches to image-to-image mapping and full-field image analysis remain poorly understood. The work presented in this paper is twofold. First, we made a significant extension to the Mechanical MNIST dataset designed to enable the investigation of full-field QoI prediction. Specifically, we added Finite Element simulation results of quasi-static brittle fracture in a heterogeneous material captured with the phase-field method. This problem was chosen as a broadly relevant ”challenge problem” for full-field QoI prediction. Second, we investigated multiple Deep Neural Network architectures and subsequently established strong baseline performance for predicting full-field QoI. We found that a MultiRes-WNet architecture with straightforward data augmentation achieves 0.80% and 0.34% Mean Absolute Percentage Error on full-field displacement prediction for Equibiaxial Extension and Uniaxial Extension datasets in the Mechanical MNIST Fashion dataset, respectively. In addition, we found that our MultiRes-WNet architecture combined with a basic Convolutional Autoencoder achieves a mean F1 score of 0.87 on the newly added Mechanical MNIST Crack Path dataset. In addition to presenting the results in this paper, we have released our model implementation and the Mechanical MNIST Crack Path dataset under open-source licenses. We anticipate that future researchers will directly use our model architecture on related datasets and potentially design models that exceed the baseline performance for predicting full-field QoI established in this paper.

Excellent energy storage properties in NaNbO3-based lead-free ceramics by modulating antiferrodistortive of P phase

The adjustment of the antiferroelectricity of a perovskite cell and the reversibility of antiferroelectric (AFE) -ferroelectric (FE) phase transition under electric field is very important for achieving excellent energy storage properties in AFEs. In this work, obvious change of antiferroelectricity was found in novel Na(Nb1−xSbx)O3 lead-free ceramics fabricated via a conventional solid-state reaction method. Repeatable double P-E loops with large EA-F ~28 kV/mm and large EF-A ~10 kV/mm were obtained in the x = 0.1 ceramic with AFE P phase at room temperature, resulting in excellent energy storage properties with Wrec ~3.4 J/cm3, large CD ~366 A/cm2, high PD ~26 MW/cm3 as well as fast discharge rate t0.9 ~75 ns. The multiscale structure analysis results indicate that the increased antiferrodistortive (oxygen octahedral tilting) degree and the decreased off-centering displacements of B-site cations after the substitution of Sb for Nb make the main contributions to the achievement of stable AFE phase and reversible AFE-FE phase transition in this work. The Na(Nb1−xSbx)O3 ceramics with excellent energy storage properties show large potential for the next-generation pulse power capacitor applications, and the mechanism for modulating antiferroelectricity found in this work would provide guidance for designing high-performance AFEs.

Multiple property enhancement in bismuth ferrite‐based ferroelectrics by balancing nanodomain and relaxor state

AbstractBismuth ferrite‐barium titanate (BF‐BT)‐based ferroelectrics have received widespread attention due to its adjustable structure features and multifunctional characteristics. Property optimization (ferroelectricity, piezoelectricity, electrostrain, electrostriction) for different application scenarios can be realized by increasing BT content gradually, while it is still difficult to integrate multiple performance advantages in the same component. To solve the problem and achieve the simultaneous enhancement of property parameters, defect engineering was adopted in this work to balance domain configuration and relaxor state via selective oxides modification strategy. Compared with the nanodomain engineered relaxor ferroelectrics with improved electrostrain and degraded ferroelectricity, the defect‐mediated ceramics doped with MnO2 present both enhanced electrostrain and ferroelectricity. Multiscale structure analysis (crystal structure, defect structure, and domain structure) and property characterization (ferroelectricity, strain property, and leakage current density) suggested that the defect dipoles induced by Mn substitution can effectively refine domain size and maintain ferroelectric state at room temperature, and the easier domain switching caused by weak‐correlated polar dipoles greatly improves both the strain and ferroelectricity. Especially, the defect dipoles‐mediated nanodomain and property enhancement can be only observed in BFO‐Mn ceramics, and infeasible for other oxides (e.g., CuO and CeO2). We believe that this work can provide some guidance to modify electrical properties in BF‐BT‐based ferroelectrics.

Cld-St-And-Bearing Assemblages in the Central Southalpine Basement: Markers of an Evolving Thermal Regime during Variscan Convergence

Multiscale structural analysis is carried out to explore the sequence of superposed pre-Alpine chloritoid–staurolite–andalusite metamorphic assemblages in the polydeformed Variscan basement of the upper Val Camonica, in the central Southalpine domain. The dominant fabric in the upper Val Camonica basement is the late-Variscan S2 foliation, marked by greenschist facies minerals and truncated by the base of Permian siliciclastic sequences. The intersection with the sedimentary strata defines a Permian age limit on the pre-Alpine tectono–metamorphic evolution and exhumation of the Variscan basement. The detailed structural survey revealed that the older S1 foliation was locally preserved in low-strained domains. S1 is a composite fabric resulting from combining S1a and S1b: in the metapelites, S1a was supported by chloritoid, garnet, and biotite and developed before S1b, which was marked by staurolite, garnet, and biotite. S1a and S1b developed at intermediate pressure amphibolite facies conditions during the Variscan convergence, S1a at T = 520–550 °C and P ≃ 0.8 GPa, S1b at T = 550–650 °C and P = 0.4–0.7 GPa. The special feature of the upper Val Camonica metapelites is andalusite, which formed between the late D1b and early D2 tectonic events. Andalusite developed at T = 520–580 °C and P = 0.2–0.4 GPa in pre-Permian times, after the peak of the Variscan collision and before the exhumation of the Variscan basement and the subsequent deposition of the Permian covers. It follows that the upper Val Camonica andalusite has a different age and tectonic significance as compared to that of other pre-Alpine andalusite occurrences in the Alps, where andalusite mostly developed during exhumation of high-temperature basement rocks in Permian–Triassic times.

The role of intracratonic crustal reworking in the tectonic compartmentalization of the Juruena Terrane, SW Amazonas Craton: the Roosevelt-Guariba Transpressive Belt

The multiscale structural analysis carried out in the NNW sector of the Juruena Terrane, SE of the State of Amazonas combines structural mapping, microtectonic analysis and aeromagnetic data analysis. It shows a complex structural and metamorphic history composed of successive deformation events, responsible by the formation of its tectonic framework. Event D2 (1520-1460 Ma) is responsible for the main structure of the NNW sector of the Juruena Terrane, and it generates a dextral transpressive shear zone NW-SE, called Roosevelt-Guariba Transpressive Belt (RGTB). This is an intracontinental high-temperature, medium-pressure tectonothermal event, compatible with the conditions of the upper amphibolite to granulite facies. The RGTB controls the tectonic compartmentation of the region, particularly affecting the Granitic Gneiss Domain (1760-1750 Ma). Other sectors, such as the Supracrustal Rock Domain (1800-1730 Ma) and the Pre-Juruena geological-structural association (>1830 Ma), are subordinately affected. Event D2 overlaps the regional structure E-W (ENE-WSW) attributed to Event D1 (1690-1630 Ma), which is restricted to the deep basement in the NNW sector, but dominant in the south central sector of the Juruena Terrane. There are also two late brittle-ductile to brittle deformation events (events D3 and D4). Event D3 (1320-1300 Ma) is represented by NE-SW cataclastic and shear zones, commonly serving as conduits for hydrothermal fluids relative to gold mineralizations. Event D4 is constituted by normal faults and fractures that reactivate RGTB shear zones, limiting Neoproterozoic and Paleozoic-Mesozoic sedimentary exposures. The tectonic structural model proposed in this study reinforces the interpretation that the Juruena Terrane evolved from a foreland basin, which was formed during the Juruena Orogen and whose basement is the Tapajos Crust. This basin was preserved from the tectono-thermal effects of the end of the Statherian (D1), and it was only during event D2, after emplacement of the RGTB, that it underwent high-grade deformation and metamorphism, whose driving force is attributed to the propagation of stresses in pericratonic regions, associated with Calymmian orogens. The successive events are related to the cratonization of the Juruena Terrane, represented by late crust reactivation (D3) and neotectonic events (D4).

Influence of microstructure and atomic-scale chemistry on the direct reduction of iron ore with hydrogen at 700°C

Steel is the most important material class in terms of volume and environmental impact. While it is a sustainability enabler, for instance through lightweight design, magnetic devices, and efficient turbines, its primary production is not. Iron is reduced from ores by carbon, causing 30% of the global CO2 emissions in manufacturing, qualifying it as the largest single industrial greenhouse gas emission source. Hydrogen is thus attractive as alternative reductant. Although this reaction has been studied for decades, its kinetics is not well understood, particularly during the wüstite reduction step which is much slower than hematite reduction. Some rate-limiting factors of this reaction are determined by the microstructure and local chemistry of the ores. Here, we report on a multi-scale structure and composition analysis of iron reduced from hematite with pure H2, reaching down to near-atomic scale. During reduction a complex pore- and microstructure evolves, due to oxygen loss and non-volume conserving phase transformations. The microstructure after reduction is an aggregate of nearly pure iron crystals, containing inherited and acquired pores and cracks. We observe several types of lattice defects that accelerate mass transport as well as several chemical impurities (Na, Mg, Ti, V) within the Fe in the form of oxide islands that were not reduced. With this study, we aim to open the perspective in the field of carbon-neutral iron production from macroscopic processing towards better understanding of the underlying microscopic transport and reduction mechanisms and kinetics.

Prediction of mechanical and thermal properties of particle reinforced hydrogel composites using the structural genome approach

In this paper, the structural genome approach is used for multiscale analyses to predict the mechanical and thermal properties of particle reinforced hydrogel composites. First, the structure genome model of particle reinforced hydrogel composites is created by the random sequential adsorption algorithm. Then the mechanical properties and equivalent thermal conductivity of hydrogel composites are numerically studied by the structural genome approach. The effects of particles with different volume fractions and material properties on their mechanical and thermal properties are investigated. From the simulation results, it can be found that within a certain range of volume fraction, the mechanical properties and equivalent thermal conductivity of hydrogel composites are positively correlated with the volume fractions of particles. We also find that with the increase of the mechanical properties and thermal conductivity of particles, the properties of hydrogel can be improved and eventually reach stabilization. The structural genome approach shows excellent efficiency in multiscale structure analysis. It is a convenient method for the simulation of complex soft material composites.

Agro and industrial residues: Potential raw materials for photocatalyst development

Contamination by organic effluents is currently one of the most serious environmental problems and, as a result, the elimination of these pollutants has been widely studied, mainly with organic phenolic pollutants. Photocatalysis have been showing an interesting process in order to optimize the conventional wastewater treatments. Thus, agroindustrial waste (exhausted bark acacia) and Ziegler–Natta catalyst slurry waste were used as supports for photocatalysts. The morphology and chemical composition of the catalysts were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and the X-ray photoelectron spectroscopy (XPS). Band-gaps were determined using UV diffuse reflectance spectroscopy (DRS). Multiscale structural characterization, pore analysis and specific surface area were determined by small-angle X-ray scattering (SAXS) and N2 porosimetry 77 K. Zeta potential (ζ) measurements were carried out to verify the stability of catalyst suspensions. The photocatalysts contained Al, Mg, Si and Ti. Metallic content ranged from 0.01 to 0.83 wt%. Ti-samples showed specific surface area between from 27.3 562.30 m g-to 562.30 m² g−1, a band gap energy (2.55–3.65 eV), negative surface potential and the presence of mass and surface fractals. The prepared photocatalytic systems (catalyst with support) were evaluated for phenol photodegradation, where the greatest percentage of phenol degradation was 68.4% under UV-V % under UV–vis radiation, while industrial standard Degussa P25 showed 43.8 % degradation. Therefore, (agro)industrial waste can be used as precursors or catalytic supports of photocatalysts for application in the treatment of wastewater meeting sustainable development.

Emerging antiferroelectric phases with fascinating dielectric, polarization and strain response in NaNbO3-(Bi0.5Na0.5)TiO3 lead-free binary system

Environmentally-benign antiferroelectrics (AFEs) have attracted a great deal of attention in recent years owing to their special structure and polarization/strain-electric field response, exhibiting giant application advantages in multifunctional devices. In this work, a detailed phase diagram in a binary lead-free system between AFE NaNbO3 (NN) and ferroelectric (FE) (Bi0.5Na0.5)TiO3 (BNT) was established according to the measurement of dielectric and ferroelectric properties in combination with the multiscale structure analysis such as Raman spectra, synchrotron x-ray diffraction and transmission electron microscopy. Multiple AFE phases of different stability, crystal symmetry and domain morphology were stabilized near room temperature, involving AFE orthorhombic P (Pbma) and R (Pnma) phases in NN-rich compositions and AFE tetragonal phase (P4bm) in BNT-rich compositions, as well as field induced metastable AFE monoclinic phase (P21). Owing to the electric field induced AFE-FE phase transformation especially for relaxor AFEs with antipolar nanoregions, tunable and excellent electrical properties of temperature-stable dielectric permittivity, ultrahigh energy-storage density and efficiency and low-hysteresis high strain can be generated in the proximity of these AFEs, showing outstanding potentials in thermally-stable capacitors, dielectric energy storage and large-strain ceramic actuators for NN-BNT solid solutions.

Polyphased brittle deformation around a crustal fault: A multi-scale approach based on remote sensing and field data on the mountains surrounding the Têt hydrothermal system (Eastern Pyrénées, France)

Studying hydrothermal systems in basement environments requires knowledge of fault and fracture network distributions. This study addresses this through multi-scale structural analysis of the Têt fault and its surrounding fracture systems (Eastern Pyrénées) using remote sensing and field data. This study aims to achieve this through: 1) precisely mapping and describing the brittle fault network, 2) analysing the distribution of lineaments and outcrop-scale fractures related to these faults, 3) making comparisons to fault-kinematic evidence combined in a new regional review, 4) examining the relations between fractures features and lithology, 5) applying statistical analysis to highlight relations between different scales of deformation. The complex fault network is inherited from consecutive tectonic stages (Hercynian, Pyrenean compression, Neogene extension) and has been reactivated since the middle-Miocene. NE–SW secondary faults are abundant at the regional scale, even away from the Têt fault. Major NW–SE faults are constituted by 10s-m wide brittle core zones, and NW–SE secondary faults are concentrated around the Têt fault, attesting that they had formed at shallow crust levels after the Oligo-Miocene extension. N–S fractures, formed during Pyrenean compression, are part of the background fracturing and are scattered throughout the study area. Intersections of fault and fracture networks provide efficient permeable pathways for meteoric and hydrothermal fluids. Finally, a dislocation model reveals a lithological control on fracture apertures in crystalline rocks, which appears more preserved at depth than in metasediments. All of these elements are integrated in a global model of the hydrothermal system establishment in accordance with the faulting sequence, with the damage distribution and with the lithology. This distributed fault system could represent the surface expression of the crustal thinning revealed by recent geophysical data. The realized identification of the lithological and structural characteristics of the surrounding mountains, allowing hydrothermal circulation to establish itself, provides a better understanding of the orogenic-belt related hydrothermal systems necessary to the geothermal exploration.

A Multiscale Structural Analysis of Soft and Hard Coal Deposits in Deep High‐Gas Coal Seams

In recent years, with the increases in coal mining depths, the risk of coal seam outburst occurrences has increased. Therefore, it is of major significance to study the multiscale structures of soft and hard coal deposits in order to prevent and control the coal and gas outbursts. In this research investigation, soft and hard coal multiscale structures were comprehensively examined using various laboratory methods. The results revealed the following: (1) From a macrostructural aspect, the physical and mechanical properties of the soft coal were weaker than those of the hard coal. It was found that the majority of the examined specimens were characterized by scaly structures without blocks larger than 50 mm. The hard coal was observed to be mainly massive with only a small part being clastic. Therefore, the structural characteristics were considered to be stable. (2) From a microstructural perspective, the surfaces of the soft coal specimens were observed to be rough. The pores were found to be more developed, with the edge of pores being mainly hackly. At the same time, fractures were also relatively developed, showing good connectivity. (3) From a micropore structural perspective, it was found that the BET‐specific surface areas and BJH‐specific surface areas of the soft coal specimens were higher than those of the hard coal specimens, which indicated that the gas adsorption and diffusion migration abilities of the soft coal were greater than those of the hard coal. (4) It was suggested from the study results that the ventilation and gas extraction processes should be strengthened in the mining activities of coal seams with high, soft stratification content. At the same time, the methods used for water injection modification should be enhanced in order to improve the mechanical stability of soft coal. Consequently, the instantaneous released gases will be decelerated, and the occurrences of coal and gas outburst events in mine working faces can be prevented.

Influence of Microstructure and Atomic-Scale Chemistry on Iron Ore Reduction with Hydrogen at 700°C

Steel is the most important material class in terms of volume and environmental impact. While it is a sustainability enabler, for instance through lightweight design and magnetic devices, its primary production is not. Iron is reduced from ores by carbon, causing 30% of the global CO2 emissions in manufacturing, qualifying it as the largest single industrial greenhouse gas emission source. Hydrogen is an attractive alternative reductant. Although this reaction has been studied for decades, its kinetics is not well understood, particularly the wustite reduction step, which is much slower than hematite reduction. Some rate limiting factors of this reaction depend on the microstructure and local chemistry. Here, we report on a multi-scale structure and composition analysis of iron reduced from hematite with pure H2, reaching down to near-atomic scale. The microstructure after reduction consists of nearly pure iron crystals, containing inherited and acquired pores and cracks. We observe several types of lattice defects that accelerate mass transport inbound (hydrogen) and outbound (oxygen) as well as chemical impurities in the form of oxide islands that were not reduced. With this study, we aim to open the perspective in the field of carbon-neutral iron production from macroscopic processing towards the underlying microscopic reduction mechanisms and kinetics.

Surface–Volume–Surface EFIE Formulation for Fast Direct Solution of Scattering Problems on General 3-D Composite Metal–Dielectric Objects

A new formulation of the surface–volume–surface electric field integral equation (SVS-EFIE) combined with the regular EFIE is introduced for the electromagnetic analysis of the 3-D general composite structures of impenetrable metal and penetrable homogeneous dielectric objects. The proposed method introduces independent surface electric current densities on the boundary of each region which brings the benefit of the independent discretization of the regions according to their respective material properties and straightforward handling of the material junctions. This makes the algorithm more efficient and flexible for analysis of multiscale and large-scale composite structures in comparison with the traditional Poggio–Miller–Chang–Harrington–Wu–Tsai (PMCHWT) integral equation combined with the EFIE. The method of moment (MoM) solution of the new formulation is accelerated by the hierarchical ( $\mathcal H$ )-matrix framework. The numerical results are given to validate the new formulation. Also, the $\mathcal H$ -matrix acceleration of MoM solution of the new combined EFIE and SVS-EFIE formulation is shown to produce accurate results using only the small fraction of memory and total CPU time needed by conventional MoM.

Application of an enhanced homogenization technique to the structural multiscale analysis of a femur bone

Bone is a complex hierarchical material that can be characterized from the microscale to macroscale. This work demonstrates the application of an enhanced homogenization methodology to the multiscale structural analysis of a femoral bone. The use of this homogenization technique allows to remove subjectivity and reduce the computational cost associated with the iterative process of creating a heterogeneous mesh. Thus, it allows to create simpler homogenized meshes with its mechanical properties defined using information directly from the mesh source: the medical images. Therefore, this methodology is capable to accurately predict bone mechanical behavior in a fraction of the time required by classical approaches. The results show that using the homogenization technique, despite the differences between the used homogeneous and heterogeneous meshes, its mechanical behavior is similar. The proposed homogenization technique is useful for a multiscale modelling and it is computationally efficient.

Tectono-metamorphic evolution of UHP Zermatt-Saas serpentinites: a tool for vertical palaeogeographic restoration

ABSTRACT Within the Zermatt-Saas Zone (ZSZ, northwestern Alps), Ti-chondrodite- and Ti-clinohumite-bearing assemblages in serpentinites indicate UHP conditions. Multiscale structural analysis (1:20 scale mapping) and petrological investigation of serpentinites at Créton (upper Valtournanche) evidenced a polyphasic deformation and metamorphic history. In this locality and at regional scale, S2 is the dominant foliation that developed under HP-UHP conditions. Pre-D2 mineral and textural relicts are preserved despite the pervasiveness of S2. Pre-D2 olivine + Ti-chondrodite + spinel assemblage implies re-equilibration at 2.8–3.3 GPa and 600–630°C, in agreement with conditions recorded by coesite- and microdiamond-bearing rocks in the Cignana Lake Unit. The PT conditions inferred for syn-D2 assemblages at Créton are similar to those estimated for D2 in the surrounding serpentinites, which were dated at 65 ± 5.6 Ma. These results suggest that portions of ZSZ were subducted at high depth before 70 Ma and widen the time span during which ZSZ recorded PT peak conditions. The comparison of these data with results of a numerical model of an ocean-continent subduction system gives insights on coupling stages of this UHP unit with the surrounding ZSZ rocks during the Alpine convergence and vertical palaeogeography over subsequent time steps.

Multi-Scale Structural Analysis on Rubber Seal for Battery Pack

<div class="section abstract"><div class="htmlview paragraph">A rubber sealing for a water-cooled battery pack plays a significant role to prevent water immersion into the inside of the pack. The appropriate design including the adjacent parts achieves a weight reduction of the battery pack by reducing the battery tray thickness and the quantity of bolts used in the whole battery pack.</div><div class="htmlview paragraph">Generally, finite element analysis (FEA) is effective for the design optimization before proto-typing. However, the application to the sealing for a battery pack requires a large scale analysis, including the complicated contacts and large deformation of the rubber sealing, and results in unpractically long computation time and frequent computation errors due to the finite element distortion.</div><div class="htmlview paragraph">A multi-scale structural analysis and the process on the rubber sealing for the battery pack has been developed to solve the above issues. This approach consists of 3 steps, which are single-unit, entire-scale and detailed structural analysis.</div><div class="htmlview paragraph">The cross-section of rubber sealing was simplified as rectangular shape by modifying the mechanical property of the sealing to meet the reaction force characteristic with the original one through the Step 1. Using this simplified model, the entire-scale analysis including the whole battery pack was carried out to extract the area from the entire seal line at which the seal pressure decreases to less than the requirement or high stress of the battery tray and the cover occurs. Then, the detailed structural analysis at the extracted area was carried out for quantitative evaluation.</div><div class="htmlview paragraph">The developed structural analysis and its work flow can contribute to rubber sealing design optimization by shortening the computation time and reducing the computation errors. In this paper, the developed simulation methodology including the analysis flow are specifically presented. The simulation conditions and results for a battery pack of Battery Electric Vehicle (BEV) are shown as the case study.</div></div>

Multi-scale structural analysis of xyloglucan colloidal dispersions and hydro-alcoholic gels

Xyloglucans are highly branched, hydroxyl rich polyglucans that for their abundance in nature, biocompatibility, film forming and gelation ability may take a prominent role in the design and fabrication of biomedical devices, including in situ forming scaffolds for tissue engineering, wound dressings and epidermal sensors. The understanding and exploitation of their self-assembly behavior is key for the device performance optimization. A multi-scale analysis, conducted combining small-angle X-ray scattering, both static and dynamic light scattering at large and small angles, and rheological measurements, provides a description of the supramolecular organization of this biopolymer, from the scale of a few nano-meter, to the meso- and macro-scale both in the sol and gel states. Xyloglucan self-assembly is described as multi-step and hierarchical process with different levels of organization.