Shape Orientation Research Articles

Modeling of oxide inclusions in steel casting

A model is presented that predicts the amount and location of oxide inclusions in steel castings. A number and size distribution of inclusions, defined about a mean diameter, enters the casting system at its inlet during the filling process and are transported to their final locations in the casting. Model parameters for inclusion density, drag and wall friction are used to calculate the motion and locations of the oxide particles. Model results are presented to study the effects of casting shape and surface orientation on the final inclusion locations and distributions within castings. These results are compared with inclusion tracking experiments where the geometry of the gating system and orientation of casting cope surfaces affect the final distribution of inclusions in the castings. Measured and simulated inclusion area percent coverage, inclusion count and mean diameter are compared for a range of modelling parameters and inclusion size distributions. The size and number distribution at the casting system inlet, and other model parameters, are determined which provide the best agreement between measured and simulated inclusion area, count, and size.

Multiphoton excitation and high harmonic generation in rectangular graphene quantum dot

The multiphoton excitation and high harmonic generation (HHG) processes are considered using the microscopic quantum theory of nonlinear interaction of strong coherent electromagnetic (EM) radiation with rectangular graphene quantum dot (RGQD). The dynamic Hartree–Fock approximation is developed for the consideration of the quantum dot-laser field nonlinear interaction at the nonadiabatic multiphoton excitation regime. The many-body Coulomb interaction is described in the extended Hubbard approximation. By numerical results, we show the significance of the RGQD lateral size, shape, and EM wavefield orientation in RGQD of the zigzag edge compear to the armchair edge in the HHG process allowing for increasing the cutoff photon energy and the quantum yield of higher harmonics. The differences via edge on the elongated side of the RGQD have been explained by the investigation of the dipole momentum in both cases. Numerical results have shown that the HHG spectra have a strong anisotropy depending on the orientation of the laser wave, and the cutoff photon energy shifts toward blue with an increase in the transverse size of the RGQD.

On the occurrences and formation mechanisms of cliftonites: The case of Campo del Cielo iron meteorite

The origin and shock history of IAB meteorites are still a matter of debate. From the literature, the study of carbon phases can provide further information on the thermal conditions to which the meteorites have been exposed. Within this framework, the occurrences of cliftonites –classically defined as graphite aggregates– in a sample of the Campo del Cielo iron meteorite, were explored through optical and electron microscopy, and Raman spectroscopy. The assessment of carbon organization within the cliftonites, allowed us to propose a partial melting process of the kamacitic matrix followed by its resolidification and the optimization of the shape orientation relationships by the host crystal. This scenario combined with the cliftonites characterization at the micro and nanoscale led us to suggest a growth mechanism for the cliftonites in our Campo del Cielo sample, while the results from previous studies could account for cliftonites formation under diverse temperature-pressure-composition conditions as it is expected among different specimens and within them.

Formation of Ni–Si clusters and their relationship with dislocation loops in irradiated stainless steels

Ni–Si cluster is a major contributor to the irradiation hardening in irradiated stainless steels. The heterogeneous nucleation of Ni–Si clusters is associated with radiation-induced segregation at sinks (e.g., dislocation loops), and the possible formation of Ni–Si clusters on dislocation loops may influence the evolution process of the two types of defects. Besides, the nature of Ni–Si clusters is unclear yet, reflected by the discrepancies in the reported cluster composition. In this study, model alloys of 316L stainless steel with different Si contents were irradiated to 5 dpa at 450°C. Ni–Si clusters were analyzed by atom probe tomography and were compared with the loops observed by transmission electron microscopy. Results showed that higher Si content promoted cluster number density and size but did not change cluster composition. Discontinuous torus-shaped, continuous torus-shaped, and disk-shaped clusters were discovered. The cluster shape, size, and crystallographic orientation supported the formation of torus-shaped clusters on Frank loops and perfect loops. In large torus-shaped clusters, Si and Ni tended to concentrate in the outer and inner regions of the torus, respectively, and it may be attributed to the stress field of the interstitial-type Frank loops on which the torus-shaped clusters were formed. The constant composition of large Ni–Si clusters indicated the possible existence of a preferential Ni–Si phase. Combining the results of the 1D concentration profile and the MSM using Si atoms and Ni atoms, the Ni/Si ratio of the large clusters was between 1.6–3.0.

Oriented secondary magnetite micro-inclusions in plagioclase from oceanic gabbro

Abstract Plagioclase-hosted submicrometer to micrometer-sized oriented needle- and lath-shaped magnetite micro-inclusions with their elongation direction aligned parallel to the plagioclase [001] (PL[001]) direction were investigated using correlated optical, scanning electron, and scanning transmission electron microscopy. The PL[001] magnetite micro-inclusions formed from older generations of differently oriented magnetite micro-inclusions by recrystallization during hydrothermal alteration. Six orientation variants of PL[001] magnetite micro-inclusions occur, and they share the same shape orientation but differ in their crystallographic orientation relationships to the plagioclase host. The magnetite-plagioclase interfaces are facetted. High-resolution scanning transmission electron microscopy revealed that interface facets are aligned parallel to low-index lattice planes corresponding to oxygen layers of either magnetite or plagioclase. In addition, the linkage between prominent crystal structure elements of magnetite and plagioclase across the interfaces and accommodation mechanisms minimizing misfit between the two crystal structures were discerned. Combined evidence suggests that the shape and shape orientation, as well as the crystallographic orientation relationships between the magnetite micro-inclusions and the plagioclase host, are crystallographically controlled. The close crystal-structural link between magnetite precipitates and plagioclase host ensures a low-energy configuration driving recrystallization of older generations of differently orientated magnetite micro-inclusions into those that are aligned parallel to PL[001] and facilitates the underlying reaction kinetics. Due to their single to pseudo-single domain characteristics, the plagioclase-hosted magnetite micro-inclusions are particularly robust carriers of natural remanent magnetization. Recrystallization of differently oriented preexisting magnetite micro-inclusions into magnetite micro-inclusions with uniform shape orientation parallel to PL[001] has interesting consequences for the magnetic anisotropy of magnetite-bearing plagioclase grains.

Disentangling Modified Gravity and Massive Neutrinos with Intrinsic Shape Alignments of Massive Halos

We present two new diagnostics based on the intrinsic shape alignments of group/cluster size dark matter halos to disentangle the effect of f(R) gravity from that of massive neutrinos. Using snapshot data from a series of the DUSTGRAIN-pathfinder N-body simulations for a Planck ΛCDM cosmology and three f(R) gravity models with massive neutrinos (ν), we first determine the probability density functions of the alignment angles between the shape orientations of massive halos and the minor principal axes of the local tidal fields. The numerically obtained results turn out to agree very well with the analytic formula derived under the assumption that the anisotropic merging along the cosmic web induces the halo shape alignments. The four cosmologies, which several standard diagnostics failed to discriminate, are found to yield significantly different best-fit values of the single parameter that characterizes their analytic formulae. We also numerically determine the spatial cross-correlations between the shape orientations of neighbor group/cluster halos, and find them to be in good agreements with a fitting formula characterized by two parameters, whose best-fit values are found to differ substantially among the four models. We also discuss the limitations and caveats of these new diagnostics that must be overcome for their application to real observational data.

Factors governing surface exchange kinetics in undoped and strontium/iron co-substituted La2NiO4+δ

Surface oxygen exchange in the La2NiO4+δ and La1.5Sr0.5Ni1-yFeyO4+δ (y = 0.3, 0.4) oxides is analyzed using the data on oxygen permeability through the membranes with different thicknesses measured under various oxygen partial pressure P(O2) gradients in the 800–1000 °C range. The increase in P(O2) gradient induced surface limitations in La2NiO4+δ leading to a predominant role of surface exchange in the overall oxygen flux. The origin of surface exchange limitations in La2NiO4+δ is ascribed to a relatively fast decrease in oxygen excess and Ni3+ concentration with P(O2) reduction compared to La1.5Sr0.5Ni0.7Fe0.3O4+δ and La1.5Sr0.5Ni0.6Fe0.4O4+δ, which retained an oxygen excess. Faster surface exchange kinetics for La1.5Sr0.5Ni0.6Fe0.4O4+δ in comparison with that for La1.5Sr0.5Ni0.7Fe0.3O4+δ is interpreted on the basis of surface microstructure obtained by electron backscatter diffraction (EBSD). It is suggested that the observed changes in size, shape and crystallographic orientation of grains in La1.5Sr0.5Ni0.6Fe0.4O4+δ (compared to La1.5Sr0.5Ni0.7Fe0.3O4+δ) could result in a higher amount of 3d-metal cations in surface layers of the oxide.

Crystal Structure Controls on Oriented Primary Magnetite Micro-Inclusions in Plagioclase From Oceanic Gabbro

Abstract Oriented needle-, lath- and plate-shaped magnetite micro-inclusions in rock forming plagioclase from mafic intrusive rocks, were investigated using correlated optical microscopy and scanning transmission electron microscopy. The magnetite micro-inclusions were analysed on cuts parallel and perpendicular to the inclusion–elongation directions. The crystal structures of the two phases are in direct contact along the interfaces. The shape, shape orientation and crystallographic orientation relationships between the magnetite micro-inclusions and the plagioclase host appear to be controlled by the tendency of the system to optimise lattice match along the interfaces. The elongation direction of the inclusions ensures good match between prominent oxygen layers in the magnetite and plagioclase crystal structures across the interfaces bounding the inclusions parallel to their elongation direction. In cross-section, additional modes of lattice match, such as the commensurate impingement of magnetite and plagioclase lattice planes along the interfaces, the parallel alignment of the interfaces to low-index lattice planes of magnetite or plagioclase, or the parallel alignment to low index lattice planes of both phases are observed, which appear to control the selection of interface facets, as well as the shape and crystallographic orientation relationships between magnetite micro-inclusions and plagioclase host. The systematics of the inclusion cross-sectional shapes and crystallographic orientation relationships indicate recrystallisation of magnetite with potential implications for natural remanent magnetisation of magnetite-bearing plagioclase grains.

Critique and change: The “what”, “why”, “how”, and “so what”

Critique and change: The “what”, “why”, “how”, and “so what”

Optimization of air inlet features of an active indirect mode solar dryer: A response surface approach

The effect of air flowing into an in an active indirect mode solar dryer was studied. The study aimed at optimizing the airflow features of a solar dryer of active indirect feature using Response Surface Methodology (RSM). The factors of the experiment included the product slice thickness of the experimental product and the air vent of the dryer. The two factors were considered at five levels and a total of 13 experimental runs derived. The air vent was based on the following shape orientations: square, rectangular, circular, and triangular. The thickness of the product was considered at five levels of 4, 8, 12, 16 and 20 mm. The responses from the experimental set up were the air flow rate and drag force, which were determined using established equations. The optimum values for the air flow rate and drag force were 0.0275 m3/s and 0.0476N, respectively. The corresponding optimal conditions which gave the optimum responses were 100 cm2 - square inlet and product slice thickness of 20 mm for air flow rate and 80 cm2 -rectangular inlet and product slice thickness of 20 mm for drag force, respectively. The models for predicting the responses were adequate, with r-square values 0.9463 and 0.9376 and desirabilities of 99.2 and 95.0% for air flow rate and drag force respectively. The experiment was repeated using the optimal conditions to validate the optimum responses. The variation between the predicted and experimental data was less than 8%.

Nitsche-based isogeometric approach for free vibration analysis of laminated plate with multiple stiffeners and cutouts

On the basis of the first order shear deformation and Timoshenko beam theories, a general Nitsche-based isogeometric analysis (IGA) is developed for studying the free vibration behaviors of composite plates with/without stiffeners and cutouts. Firstly, the laminated plate with/without cutout is described by several non-overlapped NURBS patches. The stiffeners are placed on the common edges of adjacent patches and share the same control points with these sub-patch edges. Then, different patches are stuck together by the means of Nitsche method. Eventually, the proposed method is implemented for analyzing the free vibration of composite plates with/without stiffener and cutout. First of all, it avoids the discretization of the stiffener and the identification of plate elements where stiffener nodes are located at, that are required in finite element method and IGA. In addition, it can handle with laminated plate with multiple stiffeners and cutouts conveniently. At first, four meshing schemes with different element sizes are implemented to validate the good convergence and accuracy of the present method in case of laminated plate with stiffener. Then, rectangular, skew and elliptical plates without stiffener and cutout are considered and the obtained natural frequencies and mode shapes agree well with those reported in literature. Furthermore, results from composite plates with/without stiffener and cutout under different boundary conditions are analyzed by considering different lay-up numbers and orientations of fiber, shapes and numbers of cutout, orientation angles and numbers of stiffener.

Extended Drones Tracking From ISAR Images With Doppler Effect and Orientation Based Robust Sub-Random Matrices Algorithm

The simultaneous imaging and tracking of drones and small UAVs is one of the most challenging problems in inverse synthetic aperture radar (ISAR) signal processing and has received significant attention recently. Wide-angle ISAR imaging may offer better resolution and richer geometrical features. Aiming at this issue, we propose a new algorithm for multiple extended drone targets (EDTs) detection and tracking from wide-angle ISAR images. Since a conventional tracking algorithm using a random matrices model (RMM) is not accurate enough to reconstruct a drone's extension by one ellipse, an appropriate technique needs to be developed for ISAR imaging and tracking of EDTs. This paper models the EDT's extension as multiple ellipses with a time-varying orientation angle and solves the resulting interference problem involving data association between the nonlinear measurements and sub-ellipses. Recently, the multi-Bernoulli (MB) filter for extended targets has been proposed with the RMM approach for linear ellipsoidal target tracking by additional state variables. However, the implementation of the MB-RMM filter for nonlinear non-Gaussian models and the Doppler effect has not been presented, especially for ISAR images. We consider linearizing the nonlinear observations to solve the nonlinearity due to the Doppler effect, target motion, and wide-angle ISAR images. We presented a new robust Sub-RMM-MB-TBD filter to obtain the estimated orientation of EDT's shape after using the range-only motion compensation that uses both range and Doppler information. Moreover, the authors applied the k-space algorithm to generate ISAR image. Simulation results demonstrate this remarkable performance.

Azimuth measurement based on OAM phase spectrum of optical vortices

The optical vortex is a new type of structured light field with a helical wavefront. Because of carrying orbital angular momentum (OAM), the optical vortex can be used to measure the shape and angular orientation of a static object in optical remote sensing. These measurements take advantage of variations in the intensity or phase of the OAM mode. In this paper, we propose a method of target azimuth measurement based on OAM phase spectrum of optical vortices. The OAM phase spectrum consists of helical phase terms in different OAM modes, where the helical phase is obtained by a four-step phase-shifting method. By using the approximate duality relationship between the OAM phase spectrum and the azimuth, we can accurately measure the azimuth of a single target or multiple targets. The resolution of the azimuth measurement is inversely proportional to the OAM scanning range. Experimentally, the target azimuth measurement by employing OAM phase spectrum analysis is realized and the measurement error is less than 2.5°. On this basis, the inverse relationship between the OAM scanning range and azimuth resolution is verified, where the error between experimental and theoretical azimuth resolution is less than 0.3°.

Image-plane self-calibration in interferometry.

We develop a process of image-plane self-calibration for interferometric imaging data. The process is based on shape-orientation-size (SOS) conservation for the principal triangle in an image generated from the three fringes made from a triad of receiving elements, in situations where interferometric phase errors can be factorized into element-based terms. The basis of the SOS conservation principle is that, for a three-element array, the only possible image corruption due to an element-based phase screen is a tilt of the aperture plane, leading to a shift in the image plane. Thus, an image made from any three-element interferometer represents a true image of the source brightness, modulo an unknown translation. Image-plane self-calibration entails deriving the unknown translations for each triad image via cross-correlation of the observed triad image with a model image of the source brightness. After correcting for these independent shifts, and summing the aligned triad images, a good image of the source brightness is generated from the full array, recovering source structure at diffraction-limited resolution. The process is iterative, using improved source models based on previous iterations. We demonstrate the technique in a high signal-to-noise context, and include a configuration based on radio astronomical facilities, and simple models of double sources. We show that the process converges for the simple models considered, although convergence is slower than for aperture-plane self-calibration for large-N arrays. As currently implemented, the process is most relevant for arrays with a small number of elements. More generally, the technique provides geometric insight into closure phase and the self-calibration process. The technique is generalizable to non-astronomical interferometric imaging applications across the electromagnetic spectrum.

Integrative Assessment for Optimizing Aesthetic Outcomes When Treating Glabellar Lines With Botulinum Toxin Type A: An Appreciation of the Role of the Frontalis.

Despite the perception that treatment of glabellar lines with botulinum toxin A (BoNTA) is straightforward, the reality is that the glabellar region contains a number of interrelated muscles. In order to avoid adverse outcomes, practitioners need to appreciate how treatment of one facial muscle group influences the relative dominance of others. In particular, practitioners need to understand the independent role of the frontalis in eyebrow outcomes and the potential for negative outcomes if the lower frontalis is unintentionally weakened by BoNTA treatment. In addition, practitioners must recognize how inter-individual variation in the depth, shape, and muscle fiber orientation among the upper facial muscles can affect outcomes. For optimal results, treatment of the glabellar complex requires a systematic and individualized approach that is based on anatomical principles of opposing muscle actions rather than a one-size-fits-all approach. This review provides the anatomical justification for the importance of an integrated assessment of the upper facial muscles and eyebrow position prior to glabellar treatment. In addition, a systematic and broad evaluation system is provided that can be used by practitioners to more comprehensively assess the glabellar region in order to optimize outcomes and avoid negatively impacting resting brow position and dynamic brow movement.

Relationships between the shape of the hoof capsule and orientation of the distal phalanx in long toe underrun heels in donkeys

SummaryBackgroundThere is limited information on the morphology, radiography and orientation of the distal phalanx in the hoof capsule in long toe underrun heels in donkeys.ObjectivesThis study aimed to determine the relationships between the hoof capsule shape and distal phalanx radiographic parameters.Study designPost‐mortem collected feet.MethodsA total of 68 cadaver front hooves with long toe underrun heels were used in the study. Lateral photographic and lateromedial radiographic parameters of the feet were obtained.ResultsThe mean hoof wall angle (HWA) was strongly significantly correlated with heel angle (HA), dorsal HWA, HA measured through radiography and distal phalanx to toe distance and was modestly correlated with distal phalanx angle, solar border of the distal phalanx angle, coronet angle and distal phalanx to frog distance. The linear hoof wall length (HWL) and heel length showed a strong and modest significant correlation with distal phalanx to bottom, dorsal HWL and distal phalanx to toe distance.Main limitationsThe feet included in the study were obtained from many yards and different body sizes.ConclusionsThis study supports an association between radiographic and morphologic parameters in long toe underrun heels. The strong and modest correlations between measured photographic and radiographic parameters may indicate the relationships between the hoof capsule shape and distal phalanx orientation.

Atomistic Simulations of the Elastic Compression of Platinum Nanoparticles

The elastic behavior of nanoparticles depends strongly on particle shape, size, and crystallographic orientation. Many prior investigations have characterized the elastic modulus of nanoscale particles using experiments or simulations; however their reported values vary widely depending on the methods for measurement and calculation. To understand these discrepancies, we used classical molecular dynamics simulation to model the compression of platinum nanoparticles with two different polyhedral shapes and a range of sizes from 4 to 20 nm, loaded in two different crystal orientations. Multiple standard methods were used to calculate the elastic modulus from stress-vs-strain data for each nanoparticle. The magnitudes and particle-size dependence of the resulting moduli varied with calculation method and, even for larger nanoparticles where bulk-like behavior may be expected, the effective elastic modulus depended strongly on shape and orientation. Analysis of per-atom stress distributions indicated that the shape- and orientation-dependence arise due to stress triaxiality and inhomogeneity across the particle. When the effective elastic modulus was recalculated using a representative volume element in the center of a large nanoparticle, the elastic modulus had the expected value for each orientation and was shape independent. It is only for single-digit nanoparticles that meaningful differences emerged, where even the very center of the particle had a lower modulus due to the effect of the surface. These findings provide better understanding of the elastic properties of nanoparticles and disentangle geometric contributions (such as stress triaxiality and spatial inhomogeneity) from true changes in elastic properties of the nanoscale material.

Sign Language Detection System Using Adaptive Neuro Fuzzy Inference System (ANFIS) Method

Sign language is a language that prioritizes communication with hands, body language, and lip movements to communicate. The deaf are the main group who use this language, often combining hand shape, hand, arm and body orientation and movement, and facial expressions to express their thoughts. The sign language detection system is designed using the Adaptive Neuro Fuzzy Inference System (ANFIS). This study uses data from the kaggle.com dataset, which is a site that provides research data on artificial intelligence. This study was conducted to recognize empty hand signals. Where it will help users naturally without any additional help. The test is carried out using a data set as evidenced by 1 display. In this process, The characteristics of the hand were carried out using the Histogram Oriented Gradient (HOG) method. Meanwhile, to separate it from the background image, it is used with color segmentation. The results of the process are then taken for classification. The classification process uses the Adaptive Neuro Fuzzy Inference System method. The results of the tests carried out for accuracy are as much as

Does Men’s Facial Sexual Dimorphism Affect Male Observers’ Selective Attention?

Facial sexual dimorphism affects observers’ physical dominance ratings. Here, we test whether such perceived dominance influences selective attention. To minimize demand characteristics, we examined whether task-irrelevant masculinized men’s faces would show an attentional bias in several experimental paradigms. Experiment 1 employed a Posner Cueing Paradigm in which participants classified shapes after a masculinized or feminized man’s face was presented. We could not find a difference in participants’ classification speeds when either feminized or masculinized face cued target position. Experiment 2 employed a Flanker Task in which participants judged letter orientation, while ignoring flanking faces. There was no observed difference in participants’ reaction time (RT) when masculinized faces flanked the target. Experiment 3 employed a Dot Probe Task, where participants were presented with a masculinized face and a feminized face to the left and right of center screen, and a target shape was presented in the location of one face. Participants’ task was to classify shape orientation. We observe a small effect of facial sexual dimorphism on participants’ classification speed. In Experiment 4, we primed participants with images meant to induce fear or arousal before each trial of a Dot Probe Task. Following the presentation of a fear inducing picture, participants RT to classify shapes when a masculinized face cued target position did not differ from when a feminized face cued target position. The two different presentation times did not create different patterns of results, indicating that masculinized faces did not induce either a cueing or inhibitory affect. Overall, we failed to support the hypothesis that people selectively attend to masculinized faces when they are presented as irrelevant information.

Morphology and Structure of Al2O3 + Graphene Low-Friction Composite Coatings

Recently, graphene and its derivatives have been of particular interest as a solid lubricant to reduce friction. The aim of this study was to investigate the morphology and structure of low-friction Al2O3 coatings containing reduced graphene oxide (rGO). Using two types of rGO, alumina coatings were produced by the sol–gel dip-coating method and characterized in terms of morphology and structure using SEM and AFM microscopy and Raman spectroscopy. It was found that composite Al2O3 + rGO coatings had diversified morphology depending on the type of graphene used. The dip-coating method used for deposition had a large impact on the morphology and contributed to the orderly arrangement of rGO nanoplates in the coating matrices. It was also shown that there is a correlation between the shape and spatial orientation of nanoplates and the tribological properties of coatings. The structural studies showed differences in the number of graphene defects in the coatings, which may indicate the chemical bonding of graphene with the alumina matrices. These differences may also be responsible for divergences in the tribological properties of the coatings depending on the type of graphene. All our findings indicate the key role of an appropriate balance between the parameters of composite coating production in terms of the desired tribological properties.