Average Aspect Ratio Research Articles

Pore shapes effects on polymer translocation.

We translocated polymers through pores of different shapes and interaction patterns in three dimensions by Langevin molecular dynamics. There were four simple cylindrical pores of the same length but with different diameters. The results showed that even though decreasing the pore diameter would always decrease the translocation velocity, it was strongly dependent on the shape of the increased pore diameter. Although increasing the pore diameter made the translocation faster in simple cylindrical pores, it was complicated in different pore shapes, e.g. increasing the diameter in the middle decreased the translocation velocity. Investigating polymer shapes through the translocation process and comparing the shapes by the cumulative waiting time for different pore structures reveals the non-equilibrium properties of translocation. Moreover, polymer shape parameters such as gyration radius, polymer center of mass, and average aspect ratio help us to distinguish different pore shapes and/or different polymers.

Piezoelectric sensors fabricated by depositing solution-grown ZnO nanorods on flexible graphene-derivative electrodes

Zinc oxide nanorods (ZnO-NRs) with high-aspect ratios can significantly enhance the voltage output of mechanically flexible piezoelectric materials. A versatile chemical synthesis process for growing long narrow ZnO-NR from nanoparticle (NP) seeds by regulating the polarity of reaction solvents is introduced in this paper. The efficient nanorod (NR) growth method produces large quantities of high-aspect ratio ZnO-NRs in the reaction solvent. For ultra-small NP seeds (AVG 10.54 nm, SD 3.69), the synthesis process creates NRs with a minimal lateral growth (AVG 13.92 nm, SD 4.77) and significant longitudinal growth (AVG 150.85 nm, SD 64.93). The average aspect ratio of ZnO-NRs in the solution is ∼10.8 (SD 2.48). Once synthesized, the ZnO-NRs are mixed with polydimethylsiloxane (PDMS) to create a thin flexible piezoelectric layer/film. The composite polymer material is spin coated on an inkjet printed graphene/carboxymethyl cellulose (G-CMC) interdigitated electrode (IDE) to form the piezoelectric layer. A dielectrophoretic alignment technique is then used to reposition the NR orientations in the composite prior to final polymer curing. In this study, three different piezoelectric composites are investigated and compared: polyhedral NPs (ZnO-NP/PDMS), non-aligned nanorods (ZnO-NRNA/PDMS), and aligned nanorods (ZnO-NRA/PDMS). Each composite is deposited on a similar IDE and tested for impact loading and low frequency mechanical bending. Under bending, the NP ZnO-NP/PDMS sensor generated 3–4 mV while the non-aligned NR ZnO-NRNA/PDMS sensor produced 70–80 mV. In contrast, the horizontally aligned NR ZnO-NRA/PDMS sensor generated 150–170 mV under the same bending conditions.

Chemical mapping of tire and road wear particles for single particle analysis

Tire and road wear particles (TRWP), which are comprised of polymer-containing tread with pavement encrustations, are generated from friction between the tire and the road. Similar to environmentally dispersed microplastic particles (MP), the fate of TRWP depends on both the mass concentration as well as individual particle characteristics, such as particle diameter and density. The identification of an individual TRWP in environmental samples has been limited by inherent characteristics of black particles, which interfere with the spectroscopic techniques most often used in MP research. The purpose of this research was to apply suitable analytical techniques, including scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX) mapping and time-of-flight secondary ion mass spectrometry (ToF-SIMS) mapping, to characterize the specific physical and chemical properties of individual TRWP. Detailed elemental and organic surface maps were generated for numerous samples including bulk tread material, cryogenically milled tire tread particles, and TRWP generated from two separate road simulator methods. Key physical and chemical characteristics of TRWP for single particle identification included (1) elongated/round shape with variable amounts of mineral encrustation, (2) elemental surface characteristics including co-localization of (S + Zn/Na) ± (Si, K, Mg, Ca, and Al), and (3) co-localization of organic surface markers, such as C6H5+ and C7H7+. Comparisons of TRWP with other polymeric (polystyrene) and non-polymeric (carbon black) particle types demonstrated that a combination of physical and chemical markers is necessary to identify TRWP. Addition of a density separation step to the single particle analysis techniques allowed for the determination of average primary TRWP particle size (34 μm by number distribution and 49 μm by volume distribution) and aspect ratio (65% of TRWP with an aspect ratio > 1.5). The use of chemical mapping techniques, such as SEM/EDX and/or ToF-SIMS mapping as demonstrated herein, can support future research efforts that aim to identify complex MP.

Fundamental Cell Morphologies Examined With Cryo-TEM of the Species in the Novel Five Genera Robustly Correlate With New Classification in Family Mycobacteriaceae.

A recent study proposed the novel classification of the family Mycobacteriaceae based on the genome analysis of core proteins in 150 Mycobacterium species. The results from these analyses supported the existence of five distinct monophyletic groups within the genus Mycobacterium. That is, Mycobacterium has been divided into two novel genera for rapid grower Mycobacteroides and Mycolicibacterium, and into three genera for slow grower Mycolicibacter, Mycolicibacillus, and an emended genus Mycobacterium, which include all the major human pathogens. Here, cryo-TEM examinations of 1,816 cells of 31 species (34 strains) belonging to the five novel genera were performed. The fundamental morphological properties of every single cell, such as cell diameter, cell length, cell perimeter, cell circularity, and aspect ratio were measured and compared between these genera. In 50 comparisons on the five parameters between any two genera, only five comparisons showed “non-significant” differences. That is, there are non-significant differences between slow grower genus Mycolicibacillus and genus Mycobacterium in average cell diameter (p = 0.15), between rapid grower genus Mycobacteroides and slow grower genus Mycobacterium in average cell length (p > 0.24), between genus Mycobacteroides and genus Mycobacterium (p > 0.68) and between genus Mycolicibacter and genus Mycolicibacillus (p > 0.11) in average cell perimeter, and between genus Mycolicibacterium and genus Mycobacterium in circularity (p > 0.73). The other 45 comparisons showed significant differences between the genera. Genus Mycobacteroides showed the longest average cell diameter, whereas the genus Mycolicibacter showed the shortest average diameter. Genus Mycolicibacterium showed the most extended average cell length, perimeter, and aspect ratio, whereas the genus Mycolicibacillus showed the shortest average cell length, perimeter, and aspect ratio. Genus Mycolicibacillus showed the highest average cell circularity, whereas genus Mycobacterium showed the lowest average cell circularity. These fundamental morphological data strongly support the new classification in the family Mycobacteriaceae, and this classification is rational and effective in the study of the members of the family Mycobacteriaceae. Because both the genus Mycolicibacterium and the genus Mycobacterium contain many species and showed larger significant standard deviations in every parameter, these genera may be divided into novel genera which show common genotype and phenotypes in morphology and pathogenicity.

Passively mode-locked Er3+ and Tm3+-doped fiber lasers by using a common gold nanorods/D-shaped fiber as saturable absorber

We demonstrate passively mode-locked erbium/thulium doped fiber lasers (TDFLs) operating at 1560/1950 nm by using a common gold nanorods (GNRs)/D-shaped fiber as saturable absorber (SA). The SA is prepared by the composite of GNRs with an average aspect ratio of 5.3 and D-shaped fiber, which has broadband absorption from 1000 nm to 3000 nm. By inserting the same SA into an erbium or thulium doped fiber laser cavity, stable passively mode-locked laser at 1560 or 1950 nm is achieved, respectively. A 1560 nm laser with a pulse width of 590 fs and a repetition frequency of 25.72 MHz is obtained for the erbium doped fiber laser (EDFL), and a 1950 nm laser with a pulse width of 373 fs and a repetition rate of 27.66 MHz is also obtained for the TDFL. Our results show that the GNRs/D-shaped fiber SA could be used for constructing broadband femtosecond fiber lasers.

Characteristics of patients with ruptured very small intracranial aneurysm sized less than 3 mm.

ObjectiveIf the size of an intracranial aneurysm is below 3 mm, clinicians rarely treat them because of the low risk of rupture. But subarachnoid hemorrhage (SAH) due to the rupture of very small intracranial aneurysm (VSIA) (saccular aneurysm sized less than 3 mm) may lead to many critical neurological complications. So we analyzed the characteristics and differences between the ruptured VSIA group and the ruptured non-VSIA group.Methods421 saccular aneurysms from patients with SAH between January 2016 and December 2019 were included. Patient information including age, sex, and medical history and information about the aneurysm including location, size, aspect ratio, inflow angle, and height-width ratio were collected. And we compared the VSIA group with non-VSIA group about these characteristicsResults12.1% (51/421) of the aneurysms were included in the VSIA group, while the non-VSIA group consisted of 87.9% of the aneurysms (370/421). The female predominance was significantly higher in the VSIA group than that in the non-VSIA group (p=0.011). No significant difference was observed in location, medical history, height-width ratio between the groups. The mean value of the inflow angle in the VSIA group was much lower than that in the non-VSIA group, but no statistically significant association between rupture risk and the inflow angle was observed. The average aspect ratio was significantly lower than that in the non-VSIA group.ConclusionsRuptured VSIA group has higher percentage of females and lower aspect ratio than ruptured non-VSIA group. Further studies regarding the characteristics of ruptured and unruptured VSIA patients is required for assistance in clinical decision related to treatment of VSIA group before the aneurysmal sac rupture.

Microstructure evolution and high-temperature mechanical properties of porous Si3N4 ceramics prepared by SHS with a small amount of Y2O3 addition

Porous Si3N4 ceramics with well-developed microstructure and high flexural strength were successfully prepared by self-propagating high temperature synthesis (SHS) using a small amount of Y2O3 as sintering additive. Influences of Y2O3 content on the phase composition, microstructure evolution, flexural strength at both room temperature and elevated temperature of ~1400 °C and their fracture behavior of the obtained porous Si3N4 ceramics were investigated. Porous Si3N4 ceramic with high average aspect ratio of 4.03 and excellent flexural strength of 101 MPa was obtained by 0.4 wt% Y2O3 addition. It also shows good strength retention of 76.6% and evidently elastic fracture behavior at 1400 °C because of its rather low amorphous intergranular phase content. With the increase of Y2O3 content, the creep resistance of sample degraded owning to the softening of amorphous intergranular thus resulting in the degradation of high-temperature strength retention.

Ensemble perception includes information from multiple spatial scales.

Most visual scenes contain information at different spatial scales, including the local and global, or the detail and gist. Global processes have become increasingly implicated in research examining summary statistical perception, initially as the output of ensemble coding, and more recently as a gating mechanism for selecting which information is included in the averaging process itself. Yet local and global processing are known to be rapidly integrated by the visual system, and it is plausible that global-level information, like spatial organization, may be included as an input during ensemble coding. We tested this hypothesis using an ensemble shape-perception task in which observers evaluated the mean aspect ratios of sets of ellipses. In addition to varying the aspect ratios of the individual shapes, we independently varied the spatial arrangements of the sets so that they had either flat or tall organizations at the global level. We found that observers made precise summary judgments about the average aspect ratios of the sets by integrating information from multiple shapes. More importantly, global flat and tall organizations were incorporated into ensemble judgments about the sets; summary judgments were biased in the directions of the global spatial arrangements on each trial. This global-to-local integration even occurred when the global organizations were masked. Our results demonstrate that the process of summary representation can include information from both the local and global scales. The gist is not just an output of ensemble representation - it can be included as an input to the mechanism itself.

CIGS Mini‐Modules with Dispensed Metallization on Transparent Conductive Oxide Layer

This article presents the application of a parallel dispensing device for low‐temperature silver paste metallization on transparent conductive oxide (TCO) layers of Cu(In1 − xGax)Se2 (CIGS) substrates as an alternative metallization technology to screen printing and inkjet printing. A curing variation experiment is performed to analyze the effect of different curing conditions on the resulting contact resistivity of the metal grid. Contact resistivity values below 5 mΩcm2 are achieved. Furthermore, CIGS mini‐modules are metallized with three different low‐temperature paste formulations obtaining a record core finger geometry of 25 μm and an average optical aspect ratio of 0.46 using 25 μm nozzle openings. The dispensed metal grid on the TCO layers achieves the comparable current density values of jsc = 32.2 mA cm−2 and the open‐circuit voltages values per cell of Voc = 672 mV as the screen printed metal grid on CIGS mini‐modules and, hence, a nominal power of 2.05 W. The metal grid enables the use of broader cell widths compared with grid‐free CIGS samples and results in a reduced dead area.

Dynamic Pore-Scale Network Modeling of Spontaneous Water Imbibition in Shale and Tight Reservoirs

Spontaneous water imbibition plays an imperative role in the development of shale or tight oil reservoirs. Spontaneous water imbibition is helpful in the extraction of crude oil from the matrix, although it decreases the relative permeability of the hydrocarbon phase dramatically. The dynamic pore-scale network modeling of water imbibition in shale and tight reservoirs is presented in this work; pore network generation, local capillary pressure function, conductance calculation and boundary conditions for imbibition are all presented in detail in this paper. The pore network is generated based on the characteristics of Barnett shale formations, and the corresponding laboratory imbibition experiments are matched using this established dynamic pore network model. The effects of the wettability, throat aspect ratio, viscosity, shape factor, micro-fractures, etc. are all investigated in this work. Attempts are made to investigate the water imbibition mechanisms from a micro-scale perspective. According to the simulated results, wettability dominates the imbibition characteristics. Besides this, the viscous effects including viscosity, initial capillary pressure and micro-fractures increase the imbibition rate, while the final recovery factor is more controlled by the capillarity effect including the cross-area shape factor, contact angle and the average pore-throat aspect ratio.

Enhanced dielectric properties of polyvinylidene fluoride-based composite films with layered perovskite KCa2Na3Nb6O19-derived fillers

A polyvinylidene fluoride (PVDF)-based composite film embedded with plate-like fillers was investigated as a novel dielectric composite material that can serve as a candidate film capacitor. Plate-like particles of the dielectric Ca2Na3Nb6O19 (CNN6) filler material were prepared through liquid-phase exfoliation of KCa2Na3Nb6O19 synthesized by a conventional solid-state reaction method. CNN6 fillers with an average aspect ratio of 2.0 were successfully dispersed in a PVDF matrix without large aggregation using a solution blending and casting method. The resultant CNN6/PVDF composite film exhibited higher breakdown strength than a dielectric PVDF-based composite embedded with spherical BaTiO3 fillers. The superiority of the plate-like filler particles over spherical filler particles was qualitatively confirmed by finite element simulation using a simplified filler/matrix model. A CNN6/PVDF composite film with a thickness of 3.8 µm exhibited a high capacitance density of 10.1 F m−3, which was three times higher than that of a biaxially oriented polypropylene film currently used for film capacitors in the power control units of hybrid vehicles.

Synthesis of thin alpha alumina platelets with a large aspect ratio

Since α-Al2O3 platelets with small thickness and large aspect ratio are needed in various applications, it is of great importance to control their morphology. In the present work, we successfully fabricated α-Al2O3 platelets with small average thickness below 100 nm and large average aspect ratio above 100 by molten-salt method, using Al2(SO4)3 as the raw material, eutectic mixtures of Na2SO4 and K2SO4 as the molten salt as well as TiO2 and SiO2 as the co-dopants. The effects of calcination temperature, seeds amount and seeds morphology on the final morphology of α-Al2O3 platelets were investigated. The growth mechanism of the α-Al2O3 platelets in molten salt was also discussed. A new growth mechanism of α-Al2O3 platelets in molten salt has been proposed, which is different from previous mechanism but can explain the two different phenomena caused by seeds with different sizes and quantity.

Pre-strain effect on twinning and de-twinning behaviors of Mg-3Li alloy traced by quasi-in-situ EBSD

In the current study, the impact of pre-tensile strain (PTS) on twinning and de-twinning behaviors of a low c/a ratio extruded Mg–3Li alloy sheet was systematically investigated by measuring twin characteristic parameters via quasi-in-situ electron backscatter diffraction (EBSD) during subsequent compression and re-compression. The high PTS favored more prismatic <a> dislocation activities at the extruded samples. After extrusion direction (ED)-compression, with increasing the PTS, twin incidence enhanced and twin growth was hindered. This gave rise to a high average twin aspect ratio of the ED-compressed high PTS sample, but twin area fractions were similar as the PTS increased. During ED-re-compression, twin growth dominated twinning. The high PTS induced a low twin growth rate, and this finding was more remarkable in large size twins. Only the shrinkage and disappearance of twins (de-twinning), but no any new twins, were observed after normal direction (ND)-re-compression. The high PTS resulted in a low twin shrinkage rate, especially for large size twins. Both friction stress and back stress played significant roles on twin growth and shrinkage by controlling twin boundary motion (TBM). Impeding the TBM, by introducing the PTS, to some extent promoted the increase of compressive strength during twinning and de-twinning.

Control of planar fabrics on the development of tensile damage zones under high-speed deformation: An experimental study with granite and gneiss

We have investigated the laboratory-scale, high-strain rate tensile failure processes responsible for Mode-I breccia dike formation in impact structures. Brazilian disc experiments with granite (isotropic) and gneiss (foliated) samples were performed on a Split Hopkinson Pressure Bar, equipped with high-speed photography. For the gneiss samples, the gneissic foliation was oriented (θ) at 0, 45 and 90° to the compression direction. Time-series images show the transient states of tensile rupture localization and propagation, leading to in situ fragmentation of the rocks. Granite samples produced a single incipient tensile rupture, accommodating pulverized clasts, whereas the gneisses underwent failure by way of major fracture and a network of secondary tensile fractures, forming large elongate clasts. For gneisses, θ greatly influenced the secondary crack growth, forcing propagation trajectories to orient preferentially either along or across the foliation. The two types of target rocks produced contrasting clast geometry in the fracture zones. The granite had mostly small clasts (<10 mm), with average aspect ratios around 1:2, whereas the gneisses produced larger clasts (<40 mm) with aspect ratios, 1:5, 1:4 and 1:4 for θ = 0, 45 and 90°, respectively. This study demonstrates that monomict breccia dikes could form in situ, rather than by a tensile dilation followed by infilling.

Rock Anelasticity, Pore Geometry and the Biot–Gardner Effect

The anelastic properties of porous rocks depend on the pore characteristics, specifically, the pore aspect ratio and the pore fraction (related to the soft porosity). At high frequencies, there is no fluid pressure communication throughout the pore space and the rock becomes stiffer than at low frequencies, where the pore pressure is fully equilibrated. The models considered here include explicit pore geometry information in determining the poroelastic parameters. They are extensions of the EIAS (equivalent inclusion-average stress) and CPEM (cracks and pores effective medium) models to the whole frequency range, based on the Zener model. Knowing the degree of stiffness dispersion between the low- and high-frequency limits, we fit experimental data in the whole frequency range and obtain the average crack aspect ratio and soft porosity as a function of effective pressure. Then, we compute the dispersion and quality factor of the bulk, shear and Young moduli, and the P- and S-wave seismic velocities and quality factors as a function of frequency. However, when measuring axial or volumetric motions along a cylindrical sample, there is fluid flow at the ends of the sample in the experiments considered here. This generates dispersion and attenuation due to axial flow of the pore fluid, which does not occur for a plane wave in unbounded media. This phenomenon is called “drained/undrained transition" Pimienta et al. (J Geophys Res Solid Earth; https://doi.org/10.1002/2017JB014645 , 2017). Actually, it is an axial version of the Biot–Gardner (BG) effect, and implies an “artificial" (mesoscopic) attenuation peak (and dispersion) due to the generation of slow (diffusion) Biot modes at the cylinder boundary, inducing a global flow at the scale of the sample. The classical BG effect is due to fluid flow along the radial direction, on the basis of open-pore conditions at the sides of the sample. In this case, the sides are sealed. To use the EIAS and CPEM models, the BG effect has to be removed to obtain the intrinsic Q of the rock. The models are applied here for measurements on sandstone. The axial BG effect is more evident if the intrinsic attenuation is weak or absent. An example is Lavoux limestone, which has a bimodal porosity distribution, with an equal proportion of intragranular microporosity and intergranular macroporosity (round pores). In this case, the attenuation and dispersion are related to the BG effect, since no squirt flow is detected due to the absence of cracks. We verified that the bulk and Young moduli obtained from the axial and hydrostatic oscillations are consistent with each other, and that the theoretical description of the axial BG effect shows some discrepancies with the data.

Green hydrothermal synthesis of high aspect ratio wollastonite nanofibers: Effects of reaction medium, temperature and time

Wollastonite 1D nanostructures have attracted widespread concern for their wide applications in biomedical, constructions and many more, which however have been synthesized via high temperature solid state method or wet precipitation method which required organic template. Herein, a controllable green hydrothermal route is used to produce high aspect ratio wollastonite nanofibers. The effect of hydrothermal synthesis parameters on the aspect ratio of synthetic wollastonite nanofibers (SWN) were investigated and the hydrothermal formation mechanism was proposed. The formation of nanofiber starts from the nuclei formation in supersaturated solution then followed by the crystal growth. The synthesis reactions were conducted under different conditions with reaction medium containing different ethanol composition and temperature from 160 °C to 240 °C for 8 h to 32 h. The SWN produced was characterized using XRD, FTIR, TGA and FESEM analysis techniques. It is proven that all wollastonite produced were in nanofiber form with the average aspect ratio ranging from 10 to 20, except for those synthesized at 160 °C which mainly has irregular grain shape. The reaction medium consisting of 80% water and 20% ethanol, which was heated at 200 °C for 16 h, resulted in SWN with the highest aspect ratio of 20.15. The study demonstrated that the hydrothermal synthesis parameters can be manipulated to produce SWN with various aspect ratios to meet its demand in different applications.

Integration and segmentation conflict during ensemble coding of shape.

During ensemble coding, the visual system extracts summary information from input that has been integrated, facilitating gist-level judgments about objects and features that belong together. In contrast, input can be segmented, allowing for quick categorical distinctions between objects. Integration and segmentation usually work in parallel but may sometimes conflict in the context of ensemble coding. To investigate this possibility, we examined summary perception of aspect ratio (i.e., "tallness/flatness"). Aspect ratio has a category boundary (e.g., a circle), and individual aspect ratios may be perceptually exaggerated-segmented-away from this boundary. We predicted that summary perception of multiple aspect ratios would be disrupted when, as a set, they spanned the category boundary, since integration and segmentation would then be at odds. We found that when observers reported the average aspect ratio of a set of ellipses, they were less sensitive to the mean of sets that included both tall and flat ellipses, compared to sets comprised of tall or flat ellipses. Follow-up experiments suggest this occurred because segmentation distorted the appearance of ellipses away from the category boundary, exaggerating set heterogeneity. These experiments advance understanding of how the visual system summarizes information by showing that integration and segmentation can conflict. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Morphology and topology of dolostone lithons in the regional Carboneras Fault Zone, Southern Spain

Dolostones in a Neogene strike-slip fault zone are described. Two main types of structural features are recognised: (i) Background deformation in the form of a network of bedding-perpendicular and hybrid conjugate fractures, barren fractures and bedding-parallel stylolites. (ii) Fault-related features include breccias and cataclasites. Orthorhombic rock lithons are generated from the intersection of fracture sets with bedding and/or joints. Lithon size and morphology change across the dolostone fault block gradually producing a tetragonal or isometric shape. The lithons are 1–2 cm in dimension (only ~ 20% outside this range) and have an average cross-sectional aspect ratio of 1.6, irrespective of size or structural position. Topology is analysed using nodes and branches, ranging from isolated (I- node and I-I branch) to connected (Y- and X-nodes, and I-C to C-C branches) respectively. The quantitative description of the geometrical and topological analysis of the dolostone lithons suggest that they become more connected and interact within the dolostone fault blocks. Assessing the change in topology and lithons connectivity have important implications for subsurface reservoirs and aquifers hosted in dolostone-fault zones.

Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics

Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) lead-free ceramics demonstrated excellent dielectric, ferroelectric, and piezoelectric properties at the morphotropic phase boundary (MPB). So far, to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics, researchers have mostly focused on the influence of spherical grain shape change. In this study, BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route. X-ray diffraction (XRD) and selected area electron diffraction (SAED) performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry. Scanning electron microscopy (SEM) image showed that BCZT ceramics have kept the 1D rod-like grains with an average aspect ratio of about 4. Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric (ɛr = 11,906, tanδ = 0.014, Pr = 6.01 μgC/cm2, and Ec = 2.46 kV/cm), and electrocaloric properties (ΔT = 0.492 K and gZ = 0.289 (K·mm)/kV at 17 kV/cm) with respect to spherical BCZT ceramics. Therefore, rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.

The Average Grain Size and Grain Aspect Ratio in Metal Laser Powder Bed Fusion: Modeling and Experiment

The additive manufacturing (AM) process induces high uncertainty in the mechanical properties of 3D-printed parts, which represents one of the main barriers for a wider AM processes adoption. To address this problem, a new time-efficient microstructure prediction algorithm was proposed in this study for the laser powder bed fusion (LPBF) process. Based on a combination of the melt pool modeling and the design of experiment approaches, this algorithm was used to predict the microstructure (grain size/aspect ratio) of materials processed by an EOS M280 LPBF system, including Iron and IN625 alloys. This approach was successfully validated using experimental and literature data, thus demonstrating its potential efficiency for the optimization of different LPBF powders and systems.