Using a cross section to train veterinary students to visualize anatomical structures in three dimensions

Abstract Flow patterns for compressible fluids at supersonic velocities are discussed, and it is shown that shock fronts form when neighboring Mach lines (envelopes of wave fronts originating from point disturbances) intersect. A criterion for divergence of Mach lines is developed for cases in which the passage is symmetrical in two or three dimensions and has a straight axis. This criterion is used as the basis for designing supersonic nozzles and diffusers. The analysis indicates that only a nozzle of infinite length can discharge a parallel stream into a tube of constant cross section without the formation of shock fronts. Methods are presented for designing nozzles of finite length, with the intensity of shock fronts reduced to as small a value as possible, and it is shown that nozzles of reasonable length may be designed so that shock fronts are insignificant. Experimental observations indicate that the proposed method of nozzle design is a practical one. With regard to supersonic diffusers having a straight axis, it is shown that shock fronts cannot be avoided, even though the diffuser is of infinite length. However, the methods of this paper may be used as an aid in determining the best diffuser design.

Download Full-text

Reflected entropy for an evaporating black hole

Journal of High Energy Physics ◽

10.1007/jhep11(2020)155 ◽

2020 ◽

Vol 2020 (11) ◽

Cited By ~ 1

Author(s):

Tianyi Li ◽

Jinwei Chu ◽

Yang Zhou

Keyword(s):

Black Hole ◽

Cross Section ◽

Early Time ◽

Three Dimensions ◽

Late Time ◽

Mixed States ◽

Correlation Measure ◽

Extremal Surface ◽

Brane Model ◽

The Right

Abstract We study reflected entropy as a mixed state correlation measure in black hole evaporation. As a measure for bipartite mixed states, reflected entropy can be computed between black hole and radiation, radiation and radiation, and even black hole and black hole. We compute reflected entropy curves in three different models: 3-side wormhole model, End-of-the-World (EOW) brane model in three dimensions and two-dimensional eternal black hole plus CFT model. For 3-side wormhole model, we find that reflected entropy is dual to island cross section. The reflected entropy between radiation and black hole increases at early time and then decreases to zero, similar to Page curve, but with a later transition time. The reflected entropy between radiation and radiation first increases and then saturates. For the EOW brane model, similar behaviors of reflected entropy are found.We propose a quantum extremal surface for reflected entropy, which we call quantum extremal cross section. In the eternal black hole plus CFT model, we find a generalized formula for reflected entropy with island cross section as its area term by considering the right half as the canonical purification of the left. Interestingly, the reflected entropy curve between the left black hole and the left radiation is nothing but the Page curve. We also find that reflected entropy between the left black hole and the right black hole decreases and goes to zero at late time. The reflected entropy between radiation and radiation increases at early time and saturates at late time.

Download Full-text

Magnetic Resonance Imaging of Human Extraocular Muscles During Static Ocular Counter-Rolling

Journal of Neurophysiology ◽

10.1152/jn.01157.2004 ◽

2005 ◽

Vol 94 (5) ◽

pp. 3292-3302 ◽

Cited By ~ 29

Author(s):

Joseph L. Demer ◽

Robert A. Clark

Keyword(s):

Cross Section ◽

Cross Sections ◽

Three Dimensions ◽

Eye Position ◽

Ocular Torsion ◽

Resonance Imaging ◽

Central Target ◽

Ocular Reflex ◽

Adult Humans ◽

Vestibulo Ocular Reflex

The rectus extraocular muscle (EOM) pulleys constrain EOM paths. During visual fixation with head immobile, actively controlled pulleys are known to maintain positions causing EOM pulling directions to change by one-half the change in eye position. This pulley behavior is consistent with Listing's law (LL) of ocular torsion as observed during fixation, saccades, and pursuit. However, pulley behavior during the vestibulo-ocular reflex (VOR) has been unstudied. This experiment studied ocular counter-rolling (OCR), a static torsional VOR that violates LL but can be evoked during MRI. Tri-planar MRI was performed in 10 adult humans during central target fixation while positioned in right and left side down positions known to evoke static OCR. EOM cross-sections and paths were determined from area centroids. Paths were used to locate pulleys in three dimensions. Significant ( P < 0.025) counter-rotational repositioning of the rectus pulley arrays of both orbits was observed in the coronal plane averaging 4.1° (maximum, 8.7°) from right to left side down positions for the inferior, medial, and superior rectus pulleys. There was a trend for the lateral rectus averaging 1.4°. Torsional shift of the rectus pulley array was associated with significant contractile cross-section changes in the superior and inferior oblique muscles. Torsional rectus pulley shift during OCR, which changes pulling directions of the rectus EOMs, correlates with known insertions of the oblique EOM orbital layers on rectus pulleys. The amount of pulley reconfiguration is roughly one-half of published values of ocular torsion during static OCR, an arrangement that would cause rectus pulling directions to change by less than one-half the amount of ocular torsion.

Download Full-text

3D Simulation of Dean Vortices at 30° Position of 180° Curved Duct of Square Cross-Section under Opposing Buoyancy

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.389.153 ◽

2018 ◽

Vol 389 ◽

pp. 153-163 ◽

Cited By ~ 1

Author(s):

Mourad Mokeddem ◽

Houssem Laidoudi ◽

Mohamed Bouzit

Keyword(s):

Cross Section ◽

Richardson Number ◽

Three Dimensions ◽

Governing Equations ◽

Dean Number ◽

Thermal Buoyancy ◽

Dean Vortices ◽

Flow And Heat Transfer ◽

Curved Duct ◽

Physical Phenomena

3D numerical simulations are performed to analyze correctly the effect of opposing thermal buoyancy and Dean number on Dean vortices, fluid flow and heat transfer through 180° curved duct of square cross-section. Due to tremendous found results, this works emphasizes only at the position 30° of the bend portion. The governing equations involving momentum, continuity and energy are solved in three dimensions under these assumptions: the flow is laminar, steady-state and incompressible. The present study is investigated in the range of these conditions: Dean number of De = 125 to 150, Richardson number of Ri = 0 to 2 at Pr = 1. The principal obtained results are represented in forms of streamlines and isotherms to analyze and to discuss the found physical phenomena. The local Nusselt number along the wall of square cross-section is also computed and presented. The main found point is that the opposing thermal buoyancy has a tendency to eliminate the effect of centrifugal force at the position 30° of bend portion of 180° curved duct.

Download Full-text

Tridimensional Regression for Comparing and Mapping 3D Anatomical Structures

Anatomy Research International ◽

10.1155/2012/604543 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Kendra K. Schmid ◽

David B. Marx ◽

Ashok Samal

Keyword(s):

Shape Analysis ◽

Three Dimensional ◽

Two Dimensions ◽

Three Dimensions ◽

Coefficient Of Determination ◽

Anatomical Structures ◽

Degree Of Similarity

Shape analysis is useful for a wide variety of disciplines and has many applications. There are many approaches to shape analysis, one of which focuses on the analysis of shapes that are represented by the coordinates of predefined landmarks on the object. This paper discusses Tridimensional Regression, a technique that can be used for mapping images and shapes that are represented by sets of three-dimensional landmark coordinates, for comparing and mapping 3D anatomical structures. The degree of similarity between shapes can be quantified using the tridimensional coefficient of determination (). An experiment was conducted to evaluate the effectiveness of this technique to correctly match the image of a face with another image of the same face. These results were compared to the values obtained when only two dimensions are used and show that using three dimensions increases the ability to correctly match and discriminate between faces.

Download Full-text

Three Dimensions of the Ecological Connectivity of Fluvial Greenway

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1065-1069.2785 ◽

2014 ◽

Vol 1065-1069 ◽

pp. 2785-2788

Author(s):

Shuai Sun

Keyword(s):

Cross Section ◽

Flood Pulse ◽

Three Dimensions ◽

Flood Pulse Concept ◽

Lateral Connectivity ◽

Multiple Dimensions ◽

Longitudinal Connectivity ◽

Natural Flow ◽

Section Design ◽

River Cross Section

Fluvial greenway connectivity has multiple dimensions, so it is the complex ecosystems of nature. The longitudinal connectivity of fluvial greenway is directly related to the natural flow of water, and is sensible and cognizable. The lateral Connectivity of fluvial greenway is closely linked to the Flood Pulse Concept and river cross-section design. The vertical connectivity of fluvial greenway refers to the vertical materials and energy circulation performance and the biocoenosis relevancy in the cross section of the river. They constitute the complicated continuum system of fluvial greenway.

Download Full-text

Perfect Edge 3D™: Enabling Root-Cause Failure Analysis

International Symposium on Microelectronics ◽

10.4071/isom-wp23 ◽

2014 ◽

Vol 2014 (1) ◽

pp. 000647-000652

Author(s):

Suzanne Costello ◽

Stewart McCracken

Keyword(s):

Failure Analysis ◽

Cross Section ◽

Early Stage ◽

Ion Beam ◽

Three Dimensions ◽

High Magnification ◽

Accurate Analysis ◽

Surface Appearance ◽

Root Cause ◽

Resolution Analysis

This paper presents a novel technique used to prepare samples in cross-section using ion beam technology, MCS Perfect Edge™ and Perfect Edge 3D™. The resulting surfaces are deformation-free allowing high magnification and high resolution analysis of subtle nanometer scale features and material changes across a representative sample size (mm's rather than microns). This unique process can be used to prepare most material types and combinations of materials including metals, ceramics, plastics, organics, as well as samples combining hard and soft, thick and thin material layers with zero deformation. True sample structure and key forensic evidence is revealed allowing accurate analysis of early stage failure mechanisms and therefore diagnosis of root-cause. MCS Ltd have also developed a novel process which enables the same deformation-free cross-section whilst retaining access to the sample surface allowing high magnification and resolution analysis in three dimensions, MCS Perfect Edge 3D™. This process has transformed failure analysis capabilities by enabling direct correlation of surface appearance and crosssection condition.

Download Full-text

CURVATURE-INDUCED BOUND STATES IN QUANTUM WAVEGUIDES IN TWO AND THREE DIMENSIONS

Reviews in Mathematical Physics ◽

10.1142/s0129055x95000062 ◽

1995 ◽

Vol 07 (01) ◽

pp. 73-102 ◽

Cited By ~ 258

Author(s):

P. DUCLOS ◽

P. EXNER

Keyword(s):

Cross Section ◽

Bound States ◽

Bound State ◽

Three Dimensions ◽

Tube Radius ◽

Dirichlet Laplacian ◽

Bending Angle ◽

Thin Tube ◽

Open Questions ◽

Quantum Waveguides

Dirichlet Laplacian on curved tubes of a constant cross section in two and three dimensions is investigated. It is shown that if the tube is non-straight and its curvature vanishes asymptotically, there is always a bound state below the bottom of the essential spectrum. An upper bound to the number of these bound states in thin tubes is derived. Furthermore, if the tube is only slightly bent, there is just one bound state; we derive its behaviour with respect to the bending angle. Finally, perturbation theory of these eigenvalues in any thin tube with respect to the tube radius is constructed and some open questions are formulated.

Download Full-text

Identification of tree species from the Peruvian tropical amazon “Selva Central” forests according to wood anatomy

BioResources ◽

10.15376/biores.16.4.7161-7179 ◽

2021 ◽

Vol 16 (4) ◽

pp. 7161-7179

Author(s):

Cassiana A. Ferreira ◽

Janet G. Inga ◽

Osir D. Vidal ◽

Walter E. Goytendia ◽

Sthefany M. Moya ◽

...

Keyword(s):

Species Identification ◽

Cross Section ◽

Tree Species ◽

Wood Anatomy ◽

Anatomical Structure ◽

Forest Species ◽

Macroscopic Anatomy ◽

Production Chain ◽

Anatomical Structures ◽

Forest Exploitation

The “Selva Central” of Peru is characterized by its forest species richness that produces quality wood for countless uses. Therefore, it is necessary to identify the wood and its macroscopic anatomy, which is an important tool for the botanical identification of tree species. For this purpose, 13 sawmills located in 3 provinces were selected that exploit several tree species of “Selva Central”. Sampling of representative woods was carried out, identified by common names and, in the laboratory, they were polished, examined, and grouped by the similarity of the macroscopic anatomical structure, leading to the tree species identification. Twenty tree species were identified, belonging to 17 genera, with emphasis on the Lauraceae and Fabaceae families. However, Moraceae, Meliaceae, Lecythidaceae, Euphorbiaceae, Bignoniaceae, Myristicaceae, Combretaceae, and Burseraceae families were also identified. The anatomical structures of all the identified tree species were described, transversal and longitudinal tangential cross section images were collected, and a species identification key was constructed. The implications and importance of tree species identification via wood anatomy were discussed, in terms of controlling forest exploitation, traceability of the production chain, and the future development of an artificial intelligence tree-species identification method.

Download Full-text

Anatomical and histochemical study of Sechium edule (Jacq.) Sw.

Anales de Biología ◽

10.6018/analesbio.42.19 ◽

2020 ◽

pp. 173-181

Author(s):

Francilainy Karina de Andrade Silva ◽

Cledson dos Santos Magalhães ◽

Rafaela Damasceno Sá ◽

Flávia Carolina Lins da Silva ◽

Karina Perrelli Randau

Keyword(s):

Microscopic Study ◽

Cross Section ◽

Histochemical Study ◽

Folk Medicine ◽

Correct Identification ◽

Histochemical Analysis ◽

Anatomical Structures ◽

Lipophilic Compounds ◽

Sechium Edule ◽

The Family

Sechium edule (Jacq.) Sw. tiene un papel importante nutricional y terapéuticamente en la medicina popular, especialmente utilizado como agente hipotensor. Para ampliar la información farmacológica sobre esta especie, este trabajo tiene como objetivo el estudio histoanatómico de sus hojas. Se prepararon muestras con secciones transversales y paradérmicas de la hoja para el estudio microscópico. Para el análisis histoquímico, se utilizaron reactivos específicos para los metabolitos objetivo. A través del análisis realizado se identificaron estructuras anatómicas para la correcta identificación de la especie estudiada. La histoquímica mostró la presencia de alcaloides, triterpenos y esteroides, compuestos lipofílicos y lignina. Esta información sobre la localización de los compuestos no tiene precedentes. Así, el trabajo amplía el conocimiento sobre la especie y la familia Cucurbitaceae. Sechium edule (Jacq.) Sw. plays an important role as for its nutritional and therapeutical use in folk medicine, being especially used as a hypotensive agent. In order to expand the pharmacobotanical information on this species, this work aims to perform the histoanatomical study of its leaves. Samples containing cross-section and paradermic sections of the leaf were prepared for microscopic study. For the histochemical analysis, specific reagents were used, according to the targeted metabolites. Through the performed analysis, it was possible to identify the anatomical structures that confer the correct identification of the studied species. The histochemistry showed the presence of alkaloids, triterpenes and steroids, lipophilic compounds and lignin. This information on the localisation of the compounds is unprecedented. Thus, the work expands the knowledge about the species and the family Cucurbitaceae.

Download Full-text