Zeitschriftenartikel: „APEX ANGLE OF THE CONE“

1

Stefas, Nikolaos, Patrick A. Plonski und Volkan Isler. „Approximation algorithms for tours of orientation-varying view cones“. International Journal of Robotics Research 39, Nr. 4 (08.01.2020): 389–401. http://dx.doi.org/10.1177/0278364919893455.

Der volle Inhalt der Quelle

Annotation:

This article considers the problem of finding a shortest tour to visit viewing sets of points on a plane. Each viewing set is represented as an inverted view cone with apex angle [Formula: see text] and height [Formula: see text]. The apex of each cone is restricted to lie on the ground plane. Its orientation angle (tilt) [Formula: see text] is the angle difference between the cone bisector and the ground plane normal. This is a novel variant of the 3D Traveling Salesman Problem with Neighborhoods (TSPN) called Cone-TSPN. One application of Cone-TSPN is to compute a trajectory to observe a given set of locations with a camera: for each location, we can generate a set of cones whose apex and orientation angles [Formula: see text] and [Formula: see text] correspond to the camera’s field of view and tilt. The height of each cone [Formula: see text] corresponds to the desired resolution. Recently, Plonski and Isler presented an approximation algorithm for Cone-TSPN for the case where all cones have a uniform orientation angle of [Formula: see text]. We study a new variant of Cone-TSPN where we relax this constraint and allow the cones to have non-uniform orientations. We call this problem Tilted Cone-TSPN and present a polynomial-time approximation algorithm with ratio [Formula: see text], where [Formula: see text] is the set of all cone heights. We demonstrate through simulations that our algorithm can be implemented in a practical way and that by exploiting the structure of the cones we can achieve shorter tours. Finally, we present experimental results from various agriculture applications that show the benefit of considering view angles for path planning.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

2

ZHAO, ZIJIE, CHAO GAO, FENG LIU und SHIJUN LUO. „PLASMA FLOW CONTROL OVER FOREBODY AT HIGH ANGLES OF ATTACK“. Modern Physics Letters B 24, Nr. 13 (30.05.2010): 1405–8. http://dx.doi.org/10.1142/s0217984910023736.

Der volle Inhalt der Quelle

Annotation:

Forward blowing from a pair of plasma actuators on the leeward surface and near the apex is used to switch the asymmetric vortex pair over a cone of semi-apex angle 10° at high angles of attack. Wind tunnel pressure measurements show that by appropriate design of the actuators and appropriate choice of the AC voltage and frequency, side forces and yawing moments of opposite signs can be obtained at a given angle of attack by activating one of the plasma actuators. Further work is suggested.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

3

Bourgeois, Laure, Yoshio Bando, Satoshi Shinozaki, Keiji Kurashima und Tadao Sato. „Boron nitride cones: structure determination by transmission electron microscopy“. Acta Crystallographica Section A Foundations of Crystallography 55, Nr. 2 (01.03.1999): 168–77. http://dx.doi.org/10.1107/s0108767398008642.

Der volle Inhalt der Quelle

Annotation:

A form of turbostratic boron nitride containing a large percentage of micrometre-size conically shaped particles was investigated by transmission electron microscopy. Electron diffraction patterns revealed the presence of correlations between adjacent boron nitride layers. The diffraction patterns were also used to determine the cone apex angle of many cone-like objects. The apex angles exhibited a broad distribution from 84 to 130° with an ill defined peak in the 92–95° region. These results could be accounted for by a structure model in which conical boron nitride layers are helically wound about a disclination axis, according to overlap angles that correspond to high densities of coincidental lattice sites between successive layers. The clustering of the apex angles near 93° was attributed to the formation of a square ring during the nucleation stage. This appears to be specific to the boron nitride system.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

4

Huang, Geng, und Huan Liu. „Thermal Elastohydrodynamic Lubrication Analysis for Rolling Cone Enveloping End Face Worm Drive“. Journal of Physics: Conference Series 2459, Nr. 1 (01.03.2023): 012105. http://dx.doi.org/10.1088/1742-6596/2459/1/012105.

Der volle Inhalt der Quelle

Annotation:

Abstract To explore the thermal elastohydrodynamic lubrication performance of rolling cone enveloping end face worm drive, the mathematical model of thermal elastohydrodynamic lubrication is established based on the meshing theory of rolling cone enveloping end face worm drive and elastohydrodynamic lubrication theory. With the help of the numerical analysis software MATLAB, the thermal elastohydrodynamic lubrication performance under smooth conditions is selectively analyzed by the multigrid method. Besides, the effects of throat coefficient, cone apex radius and half cone angle of the rolling cone on thermal elastohydrodynamic lubrication performance are analyzed at the meshing out of the transmission pair. The results show that the thermal elastohydrodynamic lubrication film thickness at meshing out of the worm gear is the smallest; the oil film thickness, oil film pressure and oil film temperature are reduced from meshing in to meshing out. The oil film temperature at the interlayer is the largest. The oil film temperature at the end face worm surface is the smallest. The small half-cone angle of the cone apex radius and larger throat coefficient and cone apex radius may achieve better thermal elastohydrodynamic lubrication performance of rolling cone enveloping end face worm drive.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

5

Pincus, HJ, V. Silvestri und Y. Fahmy. „Influence of Apex Angle on Cone Penetration Factors in Clay“. Geotechnical Testing Journal 18, Nr. 3 (1995): 315. http://dx.doi.org/10.1520/gtj11000j.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

6

WANG, JIANLEI, HUAXING LI, FENG LIU und SHIJUN LUO. „CHARACTERISTICS OF FORE-BODY SEPARATE FLOW AT HIGH ANGLE OF ATTACK UNDER PLASMA CONTROL“. Modern Physics Letters B 24, Nr. 13 (30.05.2010): 1401–4. http://dx.doi.org/10.1142/s0217984910023724.

Der volle Inhalt der Quelle

Annotation:

A pair of plasma actuators with horseshoe shape is proposed for dynamic manipulation of forebody aerodynamic load at high angles of attack. Preliminary wind tunnel pressure measurements show that asymmetric force over a conical forebody with semi-apex angle 10° can be manipulated by activating the plasma actuator mounted on one side of the cone tip. Further work is suggested.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

7

Li, Peng Fei, Shi Pan, Shi Fa Wu, Yin Li Li und Wei Sun. „Fabrication of a Brush-Shaped Bent Fiber Probe for Near-Field Optics by Heated Pulling Combined with Chemical Etching“. Solid State Phenomena 121-123 (März 2007): 689–92. http://dx.doi.org/10.4028/www.scientific.net/ssp.121-123.689.

Der volle Inhalt der Quelle

Annotation:

We developed a method to fabricate bent fiber probe: heated pulling combined with chemical etching. Based on sampling theory, the resolving power of SNOM relates to the size of the probe tip. If the apex of the probe is smaller, the resolution ability of SNOM is higher. At the same time it can collect more near-field information through bigger cone angle of probe. Through improving the operation and optimizing the parameters of the heated-pulling instrument, we can obtain the probe with bent angle fiber varying from 120-150 degree, the cone angle varying from 40-90 degree and the apex diameter less than 100nm. With this new brush shape of probe, the collecting efficiency for near-field light is improved. That is to say that more near-field information is obtained. The successful ratio of the produce is more than 70%.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

8

Kererat, C. „Bearing Capacity Investigation of Silty Sandy Soil Layer Using Kunzelstab Test“. Journal of Applied Engineering Sciences 6, Nr. 1 (01.05.2016): 57–61. http://dx.doi.org/10.1515/jaes-2016-0006.

Der volle Inhalt der Quelle

Annotation:

Abstract This study presents the effect of the 3 apex angles of cone and water levels on the bearing capacity of silty sandy soil (SM) layer by interpreting results from Kunzelstab test. The SM soil layer was prepared in the testing tank and it was used as the representative of sandy soil for some area in Thailand. As the results, the cone angle increase, a number of blows increase and the adjusted factors of the blows from the apex angles of 60° and 180 º to be that of the apex angle of 90º (control) were 1.118 and 0.878, respectively. The obtained correlation between the blows and the internal friction angles of SM soil can be used for calculating the soil bearing capacity which lowers the ground surface of 0.6 m. The soil bearing capacity of SM soil below ground water level decreases 70 to 75 percent (average values from testing results) comparing to that of dry soil. Moreover, the bearing capacity of SM soil above the water level up to 0.6 m decreases 25 to 30 percent (average values from testing results) comparing to that of dry soil at the same depth. Silty sandy soil layer was found determined to have lower bearing capacity due to higher ground water level. Therefore, the calculation of the soil bearing capacity in silty sandy soil layer should be considered the effect of ground water level.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

9

Deng, Jun, Gui Hua Liu und Li Yue. „A Novel Method of Cone Fitting Based on 3D Point Cloud“. Applied Mechanics and Materials 722 (Dezember 2014): 321–26. http://dx.doi.org/10.4028/www.scientific.net/amm.722.321.

Der volle Inhalt der Quelle

Annotation:

The accuracy and stability of circular conical surface is easily influenced by the different distribution of noise and points in point cloud, when 3D point cloud data fits conical surface. For this reason, this paper proposes a novel method of establishing and optimizing the objective function with conical vertex. First, calculate the axis direction and half-apex angle of the cone; second, calculate conical vertex according to the result got in the first step; third, establish objective function with axis direction and half-apex angle and vertex, and optimize it with Levenberg-Marquardt. The method’s feasibility and robustness are verified by simulating and real experiments. The proposed algorithm has been successfully applied to a self-development 3D measuring system (TN 3DOMS) of Mianyang Saint Buffalo Technologies Limited Company.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

10

Qin, Hua, und Cun Zhi Sun. „Design of Novel Beam Demagnifier Based on Total Reflection -Refraction“. Advanced Materials Research 338 (September 2011): 22–25. http://dx.doi.org/10.4028/www.scientific.net/amr.338.22.

Der volle Inhalt der Quelle

Annotation:

A novel beam demagnifier(a cone) is presented based on total internal reflection-refraction principle, and the light propagation characteristics inside the cone were studied by using ray-tracing method and computer simulation. This paper presents several proof-theoretic results concerning a cone as a beam demagnifier under certain conditions. When the semiapex angle of the cone is equal to a series of specific values an output beam is parallel to an incident beam, the beam's diameter narrows, and the demagnification ratio of the cone is a function of apex angle and there exists a series of extreme points; the demagnifier can be used in series so as to further narrow or magnify the diameter of incident beam.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

11

Balatka, K., und S. Mochizuki. „Numerical Analysis of the Flow in an Annular-Conical Passage“. Journal of Fluids Engineering 120, Nr. 3 (01.09.1998): 513–19. http://dx.doi.org/10.1115/1.2820692.

Der volle Inhalt der Quelle

Annotation:

The purpose of this paper is to bring new insights into the flow phenomena in an annular-conical passage, which—as previously disclosed experimentally—forms a toroidal-vortex street. The two-dimensional, time dependent Navier-Stokes equations are solved with an explicit finite-difference scheme based on the Marker and Cell method. Solutions are obtained for four different cone apex angles (β = 60, 90, 120, and 180 deg). For each apex angle three cases of different passage spacing are computed. The Reynolds number ranges from Re = 100 ˜ 5000. The stress is put on the initiation and subsequent development of the toroidal-vortex street. Critical Reynolds number for several parameter settings is determined and compared with experimental results.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

12

Koprowski, Mariusz. „An analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing“. Polish Maritime Research 14, Nr. 4 (01.10.2007): 59–63. http://dx.doi.org/10.2478/v10012-007-0041-x.

Der volle Inhalt der Quelle

Annotation:

An analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing This paper presents a computer analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing. Numerical calculations were carried out with the use of the software Matlab 7.1 and Mathematica 5.2 for example conical slide bearings of different values of cone apex angles of pin and sleeve and set values of relative eccentricity and skewing angle as well as dimensionless bearing length equal to 1.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

13

Hao, Jiang Nan, Chao Gao und Yin Zhe Li. „Flow Control over a Circular-Cone-Cylinder by Unsteady Plasma Actuations“. Advanced Materials Research 160-162 (November 2010): 933–38. http://dx.doi.org/10.4028/www.scientific.net/amr.160-162.933.

Der volle Inhalt der Quelle

Annotation:

An experimental study of plasma duty-cycled actuation over slender forebodies is performed on a 20° circular-cone-cylinder model using a pair of Single Dielectric Barrier Discharge (SDBD) plasma actuators near the cone apex combined with a duty-cycle technique. The tests are carried out in a low-turbulence 3.0 m ×1.6 m low-speed wind tunnel at an angle of attack of 45°. The Reynolds number based on the cone base diameter is 50, 000. The frequency of the duty cycle is 10 Hz. The mechanisms of the unsteady excitations over various duty cycles of frequency 10 Hz are studied using ten Kulite pressure transducers mounted around a cross section of the cone forebody at angle of attack of 45°.The circumferential pressure distributions over a station on the cone forebody is measured by unsteady pressure tappings, Phase-locked averaged pressures are studied and compared with ensemble-averaged pressures.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

14

Zhang, Q. M. „A revised cone model and its application to non-radial prominence eruptions“. Astronomy & Astrophysics 653 (September 2021): L2. http://dx.doi.org/10.1051/0004-6361/202141982.

Der volle Inhalt der Quelle

Annotation:

Context. The traditional cone models achieve great success in studying the geometrical and kinematic properties of halo coronal mass ejections (CMEs). Aims. In this Letter, a revised cone model is proposed to investigate the properties of CMEs as a result of non-radial prominence eruptions. Methods. The cone apex is located at the source region of an eruption instead of the Sun center. The cone axis deviates from the local vertical by an inclination angle of θ1 and an angle of ϕ1. The length and angular width of the cone are r and ω, respectively. Results. The model was successfully applied to two CMEs originating from the western limb on 2011 August 11 and 2012 December 7. By comparing the projections of the cones with the CME fronts simultaneously observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and the Extreme-Ultraviolet Imager on board the ahead Solar TErrestrial RElations Observatory, the properties of the CMEs were derived, including the distance, angular width, inclination angle, deviation from the plane of the sky, and true speed in space. Conclusions. This revised cone model provides a new and complementary approach in exploring the whole evolutions of CMEs.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

15

Naoumova, Julia, Heidrun Kjellberg und Reet Palm. „Cone-beam computed tomography for assessment of palatal displaced canine position: A methodological study“. Angle Orthodontist 84, Nr. 3 (25.10.2013): 459–66. http://dx.doi.org/10.2319/070913-502.1.

Der volle Inhalt der Quelle

Annotation:

ABSTRACT Objective: To assess the inter- and intraexaminer reliability of a measurement method for evaluation of eruption angles and position of palatal displaced canines (PDCs) with cone-beam computed tomography (CBCT) images and to test the validity of the measured angles on a dry skull. Materials and Methods: Twenty patients (eight boys, 12 girls; age 11.4 ± 1.2 years) were randomly chosen among 67 patients from a study evaluating the interceptive effect of extracting the deciduous canine in children with PDCs. In total, 60 images were analyzed, because each patient had three CBCT examinations (baseline, 6-month control, and endpoint). Two observers assessed the following measurements twice: mesioangular and sagittal angle, vertical position, canine cusp tip, and canine apex to dental arch. The validity of the angular measurements was tested against angular measurements on a dry skull using mathematical formulations. Results: The inter- and intraexaminer mean differences for angular and linear measurements were all low and statistically insignificant (P > .05). The mean differences between the physical and 3D measurements were 0.5 ± 0.39 mm for the sagittal angle and 0.22 ± 0.19 mm for the mesioangular angle. Conclusions: Linear and angular measurements on CBCT images are accurate and precise and can be used to assess the precise position of a PDC.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

16

Zhu, Zheng-Zhong, Zuo-Chang Chen, Yang-Rong Yao, Cun-Hao Cui, Shu-Hui Li, Xin-Jing Zhao, Qianyan Zhang et al. „Rational synthesis of an atomically precise carboncone under mild conditions“. Science Advances 5, Nr. 8 (August 2019): eaaw0982. http://dx.doi.org/10.1126/sciadv.aaw0982.

Der volle Inhalt der Quelle

Annotation:

Carboncones, a special family of all-carbon allotropes, are predicted to have unique properties that distinguish them from fullerenes, carbon nanotubes, and graphenes. Owing to the absence of methods to synthesize atomically well-defined carboncones, however, experimental insight into the nature of pure carboncones has been inaccessible. Herein, we describe a facile synthesis of an atomically well-defined carboncone[1,2] (C70H20) and its soluble penta-mesityl derivative. Identified by x-ray crystallography, the carbon skeleton is a carboncone with the largest possible apex angle. Much of the structural strain is overcome in the final step of converting the bowl-shaped precursor into the rigid carboncone under mild reaction conditions. This work provides a research opportunity for investigations of atomically precise single-layered carboncones having even higher cone walls and/or smaller apex angles.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

17

BOSE, PROSENJIT, MERCÈ MORA, CARLOS SEARA und SAURABH SETHIA. „ON COMPUTING ENCLOSING ISOSCELES TRIANGLES AND RELATED PROBLEMS“. International Journal of Computational Geometry & Applications 21, Nr. 01 (Februar 2011): 25–45. http://dx.doi.org/10.1142/s0218195911003536.

Der volle Inhalt der Quelle

Annotation:

Given a set of n points in the plane, we show how to compute various enclosing isosceles triangles where different parameters such as area or perimeter are optimized. We then study a 3-dimensional version of the problem where we enclose a point set with a cone of fixed apex angle α.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

18

Bhuva, Montu P., und Shantanu K. Karkari. „The Role of Apex Angle of a Cone-Shaped Hollow Cathode on Plasma Parameters“. IEEE Transactions on Plasma Science 47, Nr. 6 (Juni 2019): 2929–36. http://dx.doi.org/10.1109/tps.2019.2914269.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

19

Adamov, N. P., A. M. Kharitonov und E. A. Chasovnikov. „Aerodynamic derivatives of a cone with a semi-apex angle 20° at supersonic velocities“. Thermophysics and Aeromechanics 21, Nr. 6 (Dezember 2014): 679–91. http://dx.doi.org/10.1134/s086986431406002x.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

20

Chamani, Hamid R., und Majid R. Ayatollahi. „Equivalent cone apex angle of Berkovich indenter in face-forward and edge-forward nanoscratch“. Wear 356-357 (Juni 2016): 53–65. http://dx.doi.org/10.1016/j.wear.2016.03.005.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

21

Дружинин, Roman Druzhinin, Андрианов, Evgeniy Andrianov, Труфанов, Viktor Trufanov, Солянников und Mikhail Solyannikov. „Theoretical dependences of separation of crushed grain on perforated cone surface“. Forestry Engineering Journal 3, Nr. 3 (12.12.2013): 164–70. http://dx.doi.org/10.12737/1782.

Der volle Inhalt der Quelle

Annotation:

For efficient use of the product obtained in the preparation of quality mixtures we developed a design of separation device to crushed grains to fractions. An expression for the determination of the maximum speed of the particle passed through the hole of rotating conical surface is got. Analyzing this expression, it was found that the value of the marginal rate of passage of the particles is affected by the angle at the apex of the cone.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

22

Ivanov, Yuri D., Vadim Y. Tatur, Ivan D. Shumov, Andrey F. Kozlov, Anastasia A. Valueva, Irina A. Ivanova, Maria O. Ershova et al. „Effect of a Conical Cellulose Structure on Horseradish Peroxidase Biomacromolecules“. Applied Sciences 12, Nr. 23 (24.11.2022): 11994. http://dx.doi.org/10.3390/app122311994.

Der volle Inhalt der Quelle

Annotation:

The effect of a dielectric conical structure on the adsorption properties of an enzyme on mica was studied by atomic force microscopy (AFM) with the example of horseradish peroxidase (HRP). The cone used was a cellulose cone with a 60° apex angle. Namely, AFM allowed us to reveal an increase in the enzyme’s aggregation during its adsorption onto mica from the solution incubated near the cone apex for 40 min—as compared with the control enzyme samples incubated far away from the cone. In contrast, no change in the HRP adsorption properties was observed after shorter (10 min) incubation of the sample near the cone. The enzymatic activity of HRP was found to be the same for all the enzyme samples studied. Our findings should be considered upon designing biosensors (in particular, those intended for highly sensitive diagnostic applications) and bioreactors containing conical structural elements. Furthermore, since HRP is widely employed as a model enzyme in studies of external impacts on enzymes determining food quality, our data can be of use in the development of food-processing methods based on the use of electromagnetic radiation (microwave treatment, radiofrequency heating, etc.).

APA, Harvard, Vancouver, ISO und andere Zitierweisen

23

Ali, Ashfaq, Naveed Ullah, Asim Ahmad Riaz, Muhammad Zeeshan Zahir, Zuhaib Ali Khan, S. Shaukat Ali Shah, Muftooh Ur Rehman Siddiqi und Muhammad Tahir Hassan. „Development and Comparative Analysis of Electrochemically Etched Tungsten Tips for Quartz Tuning Fork Sensor“. Micromachines 12, Nr. 3 (08.03.2021): 286. http://dx.doi.org/10.3390/mi12030286.

Der volle Inhalt der Quelle

Annotation:

Quartz Tuning Fork (QTF) based sensors are used for Scanning Probe Microscopes (SPM), in particular for near-field scanning optical microscopy. Highly sharp Tungsten (W) tips with larger cone angles and less tip diameter are critical for SPM instead of platinum and iridium (Pt/Ir) tips due to their high-quality factor, conductivity, mechanical stability, durability and production at low cost. Tungsten is chosen for its ease of electrochemical etching, yielding high-aspect ratio, sharp tips with tens of nanometer end diameters, while using simple etching circuits and basic electrolyte chemistry. Moreover, the resolution of the SPM images is observed to be associated with the cone angle of the SPM tip, therefore Atomic-Resolution Imaging is obtained with greater cone angles. Here, the goal is to chemically etch W to the smallest possible tip apex diameters. Tips with greater cone angles are produced by the custom etching procedures, which have proved superior in producing high quality tips. Though various methods are developed for the electrochemical etching of W wire, with a range of applications from scanning tunneling microscopy (SPM) to electron sources of scanning electron microscopes, but the basic chemical etching methods need to be optimized for reproducibility, controlling cone angle and tip sharpness that causes problems for the end users. In this research work, comprehensive experiments are carried out for the production of tips from 0.4 mm tungsten wire by three different electrochemical etching techniques, that is, Alternating Current (AC) etching, Meniscus etching and Direct Current (DC) etching. Consequently, sharp and high cone angle tips are obtained with required properties where the results of the W etching are analyzed, with optical microscope, and then with field emission scanning electron microscopy (FE-SEM). Similarly, effects of varying applied voltages and concentration of NaOH solution with comparison among the produced tips are investigated by measuring their cone angle and tip diameter. Moreover, oxidation and impurities, that is, removal of contamination and etching parameters are also studied in this research work. A method has been tested to minimize the oxidation on the surface and the tips were characterized with scanning electron microscope (SEM).

APA, Harvard, Vancouver, ISO und andere Zitierweisen

24

Al-Qahwaji, Tahseen T. Othman, und Ahmad Ameen Hussain. „Numerical Study of Tube Hydroforming Process Using Conical Dies“. Tikrit Journal of Engineering Sciences 28, Nr. 4 (01.11.2021): 25–36. http://dx.doi.org/10.25130/tjes.28.4.3.

Der volle Inhalt der Quelle

Annotation:

In this paper the effect of die angle, fluid pressure and axial force on loading paths were studied. In order to reduce the cost and time for the experimental work, ANSYS program is used for implementing the Finite Element Method (FEM), to get optimized loading paths to form a tube using double – cones shape die. Three double die angles θ (116˚ 126˚, 136˚), with three different values of tube outer diametres (40, 45, 50) mm were used. The tube length L_o and thickness t_o for all samples were 80 mm and 2 mm respectively. The most important results and conclusions that have been reached that had the highest wall thinning percentage of 26.8% with less corner filling is at tube diameter 40 mm and cone angle of (116^°) at forming pressure of 43 MPa with axial feeding 10 mm. However, the lowest wall thinning percentage was 6.9% with best corner filling at diameter 50 mm and cone were angle of (136^°) and forming pressure of 30 MPa with axial feeding 4.5 mm. Two wrinkles constituted during the initial stages of forming the tube with initial diameter of 40 mm where the ratio d⁄(t=20) (thick-walled tubes) for all die angles, while only one wrinkle is formed at the center for tubes diameter 45 and 50 mm (thin-walled tubes) . The difference in the location and number of wrinkles at the first stage of formation depends on the loading paths that has been chosen for each process, which was at the diameter 45 and 50 mm towards thin-wall cylinder deformation mode was uniaxial tension. The maximum wall thinning percentage was at the bulge apex for tube diameter 40 mm. But, the maximum wall thinning for tubes of diameters 45 and 50 mm was found at the two sides of the bulge apex .

APA, Harvard, Vancouver, ISO und andere Zitierweisen

25

Wood, N. J., und W. J. Crowther. „Yaw control by tangential forebody blowing“. Aeronautical Journal 98, Nr. 974 (April 1994): 147–54. http://dx.doi.org/10.1017/s000192400004999x.

Der volle Inhalt der Quelle

Annotation:

Summary Aircraft yaw control at high angles of attack by tangential forebody blowing has been investigated experimentally. Tests were performed in the University of Bath 21 m x 1.5 m low speed wind tunnel using a 6% scale generic combat aircraft model fitted with blowing slots in the nose cone. Six component strain gauge balance force and moment data were measured for angles of attack up to 90° for various slot geometries and locations. The effect of slot azimuthal location is demonstrated and a slot stall phenomenon described. A geometry dependent forebody/wing flowfield coupling has been identified which can lead to unexpected yawing and rolling moments. The primary source of yawing moment is shown to be the enhanced area of attached flow on the blown side of the forebody rather than direct vortex influence. The optimum slot extent and location depend on the angle of attack range over which control is required. For regions where steady vortex asymmetry is present, slots near the apex of the forebody produce severe control reversals at low blowing rates. These reversals can be minimised by placing the slots away from the apex. For control in regions where the flow is dominated by periodic vortex shedding, long slots offer efficient control to 90° angle of attack. The most suitable compromise for wide range control would appear to be a short slot placed away from the apex of the forebody.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

26

Huang, An-Bin, und Max Y. Ma. „An analytical study of cone penetration tests in granular material“. Canadian Geotechnical Journal 31, Nr. 1 (01.02.1994): 91–103. http://dx.doi.org/10.1139/t94-010.

Der volle Inhalt der Quelle

Annotation:

A numerical technique that couples the distinct-element and boundary-element methods was developed to simulate a granular soil deposit as a two-dimensional, circular disk assembly. A series of simulated penetration tests of a 60° apex angle cone was performed in normally consolidated and overconsolidated disk assemblies. The simulations allowed the cone penetration mechanisms to be evaluated from microscopic as well as the conventional, continuum mechanics points of view. Results show that the soil loading history can affect the characteristics of the soil failure mechanism and dilatancy. Lateral stress measurement behind the cone base is not sensitive to soil loading history. Finer particles appear to experience higher contact stresses and hence are more likely to be crushed by the cone penetration. Key words : cone penetration, sand, shear strength, loading history, distinct-element method.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

27

Abene, A., und V. Dubois. „Fundamental aspects of the vortex flow on cones. Angular characterization of hyperlifting vortex torques; the law of filiation“. Canadian Journal of Physics 86, Nr. 8 (01.08.2008): 1027–31. http://dx.doi.org/10.1139/p08-018.

Der volle Inhalt der Quelle

Annotation:

This paper describes in detail the fundamental aspects of the vortex flow developed on the upper surface of a cone having an apex angle of 68.6°. It is one of a large number of studies carried out in the wind tunnel of the Valenciennes University aerodynamics and hydrodynamics laboratory whereby visualizations have enabled the flow of vortex structures to be monitored and consequently their development and positioning, under the influence of apex angles and at increasing angles of incidence, to be determined and defined. The existence and the preferential nature of intervortex angles are here confirmed and it has been found, by analogy with studies carried out on other types of slender bodies, that the law of filiation is applicable to the angular characterization of hyperlifting vortex torques and to the angular correspondence existing between their main and secondary structures. These findings suggest that there is a certain universality in the behaviour of these properties although no current theory would seem to be able as yet to provide a straightforward explanation of the phenomena.PACS Nos.: 44, 47

APA, Harvard, Vancouver, ISO und andere Zitierweisen

28

Iguchi, Keiichiro, Yong-Il Kim, Mohamed Adel, Mohamed Nadim, Reina Hatanaka, So Koizumi und Tetsutaro Yamaguchi. „Association of Mandibular Posterior Anatomic Limit with Skeletal Patterns and Root Morphology Using Three-Dimensional Cone Beam Computed Tomography Comprehensive Analysis“. Diagnostics 12, Nr. 12 (02.12.2022): 3019. http://dx.doi.org/10.3390/diagnostics12123019.

Der volle Inhalt der Quelle

Annotation:

This study aimed to clarify the relationship between the mandibular posterior anatomic limit (MPAL) and skeletal anteroposterior and vertical skeletal patterns, with consideration of factors that may be related. In total, 230 people were included: 49 Japanese, 122 Egyptian, and 59 Korean people. The MPAL was measured at 0, 2, 4, and 6 mm from the root furcation along the sagittal and cuspal lines at the distance from the distal root of the mandibular right second molar to the mandibular cortex of the lingual bone. Eight different MPALs were evaluated using multiple regression analysis with explanatory variables for anteroposterior and vertical skeletal patterns and qualitative variables for age, sex, population, the presence of third molars, number of roots, presence of C-shaped roots, and Angle malocclusion classification. The MPAL was significantly larger as the mandibular plane angle decreased. The MPAL near the root apex was significantly larger as the A-nasion-point B angle increased, and the MPAL near the root apex measured at the cuspal line was significantly larger for C-type roots. The present study showed that a C-shaped root affected the MPAL in addition to the anteroposterior and vertical skeletal patterns.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

29

KASHIMA, Tomoyuki, HUN DAN, Hiroki SUZUKI und Shinsuke MOCHIZUKI. „1207 Flow field around a circular cone placed in boundary layer : Effect of apex angle“. Proceedings of Conference of Chugoku-Shikoku Branch 2016.54 (2016): _1207–1_—_1207–2_. http://dx.doi.org/10.1299/jsmecs.2016.54._1207-1_.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

30

Abd-Elhady, Mohamed S., Camilo C. M. Rindt und Anton A. Van Steenhoven. „Influence of the Apex Angle of Cone-Shaped Tubes on Particulate Fouling of Heat Exchangers“. Heat Transfer Engineering 32, Nr. 3-4 (22.03.2011): 272–81. http://dx.doi.org/10.1080/01457632.2010.495622.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

31

Chen, Bing, und Yu Guang Fan. „3D Modeling and Open-Close Motion Simulation of the Triple Eccentric Butterfly Valve“. Advanced Materials Research 215 (März 2011): 191–94. http://dx.doi.org/10.4028/www.scientific.net/amr.215.191.

Der volle Inhalt der Quelle

Annotation:

It was achieved with the benefit of excellent molding function of CAD/CAM, to solve the designing problems of rotation center of triple eccentric butterfly valve and to improve the seal performance. The Solid Edge software is applied to analyze the process of 3D modeling and motion simulation with details, as well as check both static and dynamic interference. In this way, the reasonable eccentric angle α, cone-apex angle 2β, radial eccentricity e and axial eccentricity C of valve board are acquired. It is effective to shorten the design period of triple eccentric butterfly valve, also improve the design efficiency and quality.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

32

Chu, Seng Boon, Farah Elyna Bahdun und Aina Qasrina Ahmad. „Anthropometric Evaluation of Labial Alveolar Bone Dimension of Maxillary Anterior Teeth in Kuantan Population: A Cone-Beam Computed Tomography Study“. MARCH 2023 19, Nr. 2 (13.03.2023): 55–60. http://dx.doi.org/10.47836/mjmhs.19.2.10.

Der volle Inhalt der Quelle

Annotation:

Introduction: Labial bone with adequate height and width is crucial for an implant to be successfully placed and ensure the stability of treatment outcome in the long term. The objective of this study was to employ cone-beam computed tomography (CBCT) assessment in evaluating the differences in labial alveolar bone morphology among the Kuantan population in Malaysia. Methods: A total of 60 images taken from Kulliyyah of Dentistry, International Islamic University Malaysia, between 2009 and 2019 were analysed. The root diameter, labial and palatal plate thickness, the labial bony curvature angle beneath the root apex, and the distance from the deepest point of labial bony curvature to the root apex were all measured on each of the maxillary anterior teeth. Results: At 3 mm below the cementoenamel junction, the mean (± standard deviation; SD) thickness of the labial plate for maxillary anterior teeth was 1.45 ± 0.62 mm, 1.38 ± 0.50 mm, and 1.61 ± 0.66 mm for the lateral incisor, central incisor, and canine, respectively. Below the root apex, the labial bony curvature angle was 233.63 ± 17.74 for the central incisor, 235.68 ± 17.74 for the lateral incisor and 233.81 ± 11.09 for the canine. Discussion: The result revealed a favourable labial plate in the Kuantan population when implant in the aesthetic zone is planned. Conclusion: Labial alveolar bone thickness of the Kuantan population was thin within 1.5 mm while the palatal plate was thick. Overall, labial alveolar bone was present within 3 mm below the cementoenamel junction. The labial bony curvature was highest and most curved for the central incisor compared to the lateral incisor and canine.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

33

Larionov, A. N., O. I. Polivaev, V. N. Mashin, V. P. Zakusilov und A. V. Mashina. „Kinetics of orientation processes in nematic liquid crystals in a periodically changing magnetic field“. E3S Web of Conferences 402 (2023): 14001. http://dx.doi.org/10.1051/e3sconf/202340214001.

Der volle Inhalt der Quelle

Annotation:

The method of obtaining a magnetic field, the intensity vector of which moves along a conical surface at different values of the angle between the intensity vector and the axis of rotation of the magnetic field, the values of the intensity and angular velocity of rotation of the magnetic field, is described. An increase in the phase shift between the intensity vector and the director is found with an increase in the angle at the apex of the magnetic field cone. In the studied range of angular velocities of rotation of the magnetic field at angles between the intensity vector and the axis of rotation of the magnetic field less than 60 °, the director moves synchronously with the field. An exponential character of the dependence of the orientation relaxation time, which characterizes the rapid action of liquid crystal technical devices, on pressure and temperature is established.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

34

Arani, Ali Ghorbanpour, und Reza Kolahchi. „Nonlinear vibration and instability of embedded double-walled carbon nanocones based on nonlocal Timoshenko beam theory“. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 228, Nr. 4 (17.05.2013): 690–702. http://dx.doi.org/10.1177/0954406213490128.

Der volle Inhalt der Quelle

Annotation:

Nonlinear vibration and instability of embedded double-walled carbon nanocones subjected to axial load are investigated in this article based on Eringen's nonlocal theory and Timoshenko beam model. The elastic medium is simulated as Pasternak foundation and the van der Waals forces between the inner and the outer layers of double-walled carbon nanocones are taken into account. Using von Kármán geometric nonlinearity, energy method and Hamilton’s principle, the nonlocal nonlinear motion equations are obtained. The differential quadrature method is applied to discretize the motion equations, which are then solved to obtain the nonlinear frequency and critical fluid velocity of viscous-fluid-conveying double-walled carbon nanocones. A detailed parametric study is conducted, focusing on the combined effects of the nonlocal parameter, thickness-to-length ratio, temperature change, apex angles, elastic medium and van der Waals forces on the dimensionless frequency and critical buckling load of double-walled carbon nanocones. The results show that the small-size effect on the nonlinear frequency is significant and cannot be neglected; also, the nonlinear frequency and critical buckling load decrease with increasing the cone apex-angle.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

35

Pullepu, B., E. Ekambavanan und A. J. Chamkha. „Unsteady Laminar Natural Convection from a Non-Isothermal Vertical Cone“. Nonlinear Analysis: Modelling and Control 12, Nr. 4 (25.10.2007): 525–40. http://dx.doi.org/10.15388/na.2007.12.4.14684.

Der volle Inhalt der Quelle

Annotation:

Natural convection effects of the numerical solution for unsteady, laminar, free convection flow over an incompressible viscous fluid past a non-isothermal vertical cone with surface temperature T′w(x) = T′∞ + axn varying as power function of distance from the apex (x = 0) is presented here. The dimensionless governing equations of the flow that are unsteady, coupled and non-linear partial differential equations are solved by an efficient, accurate and unconditionally stable finite difference scheme of Crank-Nicolson type. The velocity and temperature fields have been studied for various parameters Prandtl number, semi vertical angle 0◦ < φ < 90◦ and n. The local as well as average skin-friction and Nusselt number are also presented and analyzed graphically. The present results are compared with available results in literature and are found to be in good agreement.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

36

Олешко, В. И., und V. V. Nguyen. „Исследование параметров самосфокусированного электронного пучка, выведенного за анод вакуумного диода“. Письма в журнал технической физики 48, Nr. 4 (2022): 3. http://dx.doi.org/10.21883/pjtf.2022.04.52075.19053.

Der volle Inhalt der Quelle

Annotation:

The parameters of a high-current electron beam extracted from the self-focusing zone through a hole in the anode into a vacuum chamber are investigated. The beam parameters were determined from the measurement of the spatial distribution of destruction and glow arising in polymethyl methacrylate samples installed at different distances from the anode (electron beam autographs). The formation of two electron beams - a self-focused with a high energy density, propagating along the axis of the cone facing the base to the anode with an apex angle of ~ 7º and a high-energy beam of low density, propagating in a hollow truncated cone and surrounding self-focused, was found. The oscillograms of the current and the energy of the electron beams were measured.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

37

Lu, Cai-Lian, Bo-Wen Li, Mi Yang und Xiao-Qin Wang. „Relationship between alveolar-bone morphology at the mandibular incisors and their inclination in adults with low-angle, skeletal class III malocclusion—A retrospective CBCT study“. PLOS ONE 17, Nr. 3 (01.03.2022): e0264788. http://dx.doi.org/10.1371/journal.pone.0264788.

Der volle Inhalt der Quelle

Annotation:

Objective To quantitatively study the effect of the labial inclination of the mandibular central incisors on the surrounding cortical and cancellous-bone morphology among patients with low-angle, skeletal class III malocclusion, by using cone-beam computed-tomography (CBCT) imaging. Materials and methods The CBCT images of 60 patients with low-angle, skeletal class III malocclusion were divided into lingual-inclination, upright, and labial-inclination groups. The height of the alveolar bone and the thickness and area of the cortical, cancellous, and total alveolar bone were measured separately on each side of the mandibular central incisors. Results The thickness of the labial cortical bone from 6 mm below the cementoenamel junction (CEJ) to the root apex; the thickness of the labial cancellous bone at the root apex; the total thickness of the alveolar bone at the root apex; the area of labial cortical bone; the total area of labial alveolar bone; and the height of the labial alveolar bone were highest in the labial-inclination group (all P<0.05). All these variables were positively correlated with the labial inclination of the mandibular central incisors (all P<0.05). There were no statistical differences between the groups for any of the measurements on the lingual side of the teeth (P>0.05). Conclusion The morphology of the alveolar bone on the labial but not the lingual side of the mandibular central incisors was statistically significantly correlated with the labial inclination of those teeth in patients with low-angle, skeletal class III malocclusion.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

38

Pandey, Satyanand, und Lakhbir Singh Brar. „The Impact of Increasing the Length of the Conical Segment on Cyclone Performance Using Large-Eddy Simulation“. Symmetry 15, Nr. 3 (08.03.2023): 682. http://dx.doi.org/10.3390/sym15030682.

Der volle Inhalt der Quelle

Annotation:

In cyclone separators, the asymmetrical coherent structure significantly influences the velocity fluctuations and hence the cyclone performance. This asymmetric rotating vortex in the core region precesses around the cyclone axis with a frequency that depends on the cyclone geometry and operating conditions. In the present work, we studied the impact of increasing the length of the conical segment on the performance of cyclone separators as well as the precessing frequency of the asymmetrical structure. For this, five different cone lengths were considered such that the total cyclone length equalled 3.0D, 3.5D, 4.0D, 4.5D, and 5.0D (here, D is the main body diameter of the cyclone). The study was performed at three different inlet velocities, viz. 10, 15, and 20 m/s. Throughout the work, the angle of the conical segment was held fixed and resembled the reference model (which had a total cyclone length equal to 4.0D). The cyclone performance was evaluated using advanced closure large-eddy simulation with the standard Smagorinsky subgrid-scale model. Conclusive results indicate that with an increase in the cone length, the pressure losses reduce appreciably with small variations in the collection efficiency, followed by a reduction in the precessing frequency of the asymmetric vortex core. The results further indicate that the apex cone angle (or the bottom opening diameter) must be carefully adjusted when increasing the cone length.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

39

Kulnitskiy, Boris A., Igor A. Perezhogin, Dmitriy V. Batov, Vladimir D. Blank und Yuriy L. Alshevskiy. „High resolution transmission electron microscopy analysis of conical carbon nanotubes formed in the high isostatic pressure apparatus“. Image Journal of Advanced Materials and Technologies 6, Nr. 1 (21.04.2021): 10–21. http://dx.doi.org/10.17277/jamt.2021.01.pp.010-017.

Der volle Inhalt der Quelle

Annotation:

Carbon nanotubes with “herringbone” layers structure synthesized in high isostatic pressure apparatus were studied by High Resolution Transmission Electron Microscopy (HRTEM) methods. Seven different values of semi-apex angles of graphene layers were observed in different nanotubes. It is shown that semi-apex angles approximately equal to 5, 15, 25 и 35 can be regarded only to the scroll structure of the nanotubes, while 10, 20 and 30 can be regarded to both scroll either nested graphene layers curved to cones due to the embedding of the pentagon’s to them. Thus, the observation of all (seven) of these values of semi-apex angles testifies presence of scroll nanotubes in the sample under study, though it does not exclude presence of nested-cone nanotubes.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

40

Lim, You Na, Byoung-Eun Yang, Soo-Hwan Byun, Sang-Min Yi, Sung-Woon On und In-Young Park. „Three-Dimensional Digital Image Analysis of Skeletal and Soft Tissue Points A and B after Orthodontic Treatment with Premolar Extraction in Bimaxillary Protrusive Patients“. Biology 11, Nr. 3 (27.02.2022): 381. http://dx.doi.org/10.3390/biology11030381.

Der volle Inhalt der Quelle

Annotation:

Aim. To investigate the effect of changes in incisor tip, apex movement, and inclination on skeletal points A and B and characterize changes in skeletal points A and B to the soft tissue points A and B after incisor retraction in Angle Class I bimaxillary dentoalveolar protrusion. Methods. Twenty-two patients with Angle Class I bimaxillary dentoalveolar protrusion treated with four first premolar extractions were included in this study. The displacement of skeletal and soft tissue points A and B was measured using cone-beam computed tomography (CBCT) using a three-dimensional coordinate system. The movement of the upper and lower incisors was also measured using CBCT-synthesized lateral cephalograms. Results. Changes in the incisal tip, apex, and inclination after retraction did not significantly affect the position of points A and B in any direction (x, y, z). Linear regression analysis showed a statistically significant relationship between skeletal point A and soft tissue point A on the anteroposterior axis (z). Skeletal point A moved forward by 0.07 mm, and soft tissue point A moved forward by 0.38 mm, establishing a ratio of 0.18: 1 (r = 0.554, p < 0.01). Conclusion. The positional complexion of the skeletal points A and B was not directly influenced by changes in the incisor tip, apex, and inclination. Although the results suggest that soft tissue point A follows the anteroposterior position of skeletal point A, its clinical significance is suspected. Thus, hard and soft tissue analysis should be considered in treatment planning.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

41

Plonski, Patrick A., und Volkan Isler. „Approximation algorithms for tours of height-varying view cones“. International Journal of Robotics Research 38, Nr. 2-3 (31.07.2018): 224–35. http://dx.doi.org/10.1177/0278364918784353.

Der volle Inhalt der Quelle

Annotation:

We introduce a novel coverage problem that arises in aerial surveying applications. The goal is to compute a shortest path that visits a given set of cones. The apex of each cone is restricted to lie on the ground plane. The common angle [Formula: see text] of the cones represent the field of view of the onboard camera. The cone heights, which can be varying, correspond with the desired observation quality (e.g. resolution). This problem is a novel variant of the traveling salesman problem with neighborhoods (TSPN). We name it Cone-TSPN. Our main contribution is a polynomial time approximation algorithm for Cone-TPSN. We analyze its theoretical performance and show that it returns a solution whose length is at most [Formula: see text] times the length of the optimal solution where [Formula: see text] and [Formula: see text] are the heights of the tallest and shortest input cones, respectively.We demonstrate the use of our algorithm in a representative precision agriculture application. We further study its performance in simulation using randomly generated cone sets. Our results indicate that the performance of our algorithm is superior to standard solutions.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

42

KAMEDA, Takatsugu, Shinsuke MOCHIZUKI und Hideo OSAKA. „Flow around a Cone in a Thin Boundary Layer (Variation of the Surface Pressure for an Apex Angle)“. TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B 77, Nr. 775 (2011): 761–70. http://dx.doi.org/10.1299/kikaib.77.761.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

43

MAHDY, A., und H. M. ELSHEHABEY. „GYROTACTIC MICROORGANISMS FREE CONVECTION BOUNDARY LAYER FLOW ABOUT A VERTICAL TRUNCATED CONE IN NANOFLUID POROUS MEDIA“. Latin American Applied Research - An international journal 48, Nr. 1 (11.10.2019): 57–62. http://dx.doi.org/10.52292/j.laar.2018.259.

Der volle Inhalt der Quelle

Annotation:

A non-similar boundary layer analysis is presented to examine the natural convection flow over a truncated cone with fixed apex half angle; pointing downwards in a nanofluid saturated porous medium contains gyrotactic microorganisms. A suitable coordinate transformation is performed, and the obtained non-similar equations are solved by fourth order Runge–Kutta method technique coupled with shooting scheme. The effects of the thermophoresis parameter, Brownian parameter, Lewis number, bioconvection Peclet number, bioconvection Lewis number, bioconvection Rayleigh number and buoyancy ratio on the reduced Nusselt, Sherwood and density of motile microorganisms numbers have been studied. A comprehensive numerical computation is carried out for various values of the parameters that describe the flow characteristics.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

44

Tu, Kyaw L., Abdo K. Tourkmani und Singaram Srinivas. „Keratoconic Cone using its Keratometry, Decentration, and Thickness as Staging Parameters“. International Journal of Keratoconus and Ectatic Corneal Diseases 5, Nr. 3 (2016): 99–104. http://dx.doi.org/10.5005/jp-journals-10025-1129.

Der volle Inhalt der Quelle

Annotation:

ABSTRACT Aim To propose a new system of keratoconus staging using a set of parameters describing the keratoconic cone. Materials and methods Retrospective case series study of 101 keratoconic eyes of 58 patients was undertaken. They all had complete eye examination including corneal topography (Oculus Pentacam). Kmean, Kmax, higher order aberrations (HOAs) root mean square (HOARMS) value, pachymetry at thinnest point and steepest corneal meridian were obtained from Pentacam. Apex to thinnest pachymetry distance (D) was calculated using trigonometry. Pearson correlation coefficients between Kmax and HOARMS, between D on the one hand and the adjusted angle of steepest meridian, Kmean and Kmax respectively on the other, were calculated. Results There is a statistically significant positive correlation between Kmax and HOARMS (p < 0.00001). There is a negative correlation, a “horizontalization,” of the steep meridian with D increase, although it fell short of statistical significance (p = 0.07). D and Kmean (p = 0.003), and D and Kmax (p = 0.005) are significantly negatively correlated. Conclusion Kmax correlates with significant changes in HOAs. D correlates with corneal astigmatic meridian change and has a divergent path to Kmean and to Kmax. We propose a new keratometry, decentration, and thinnest pachymetry staging using the parameters Kmax (K), distance from the corneal apex to the thinnest pachymetry point (D), and corneal thickness at its thinnest point (T) to give a better, detailed description of a keratoconic cornea which could lead to improvements in assessment of its severity and treatment outcomes. How to cite this article Tu KL, Tourkmani AK, Srinivas S. Keratoconic Cone using its Keratometry, Decentration and Thickness as Staging Parameters. Int J Kerat Ect Cor Dis 2016;5(3):99-104.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

45

Oleshko V.I. und Nguyen V. V. „Investigation of the parameters of a self-focused electron beam outputted behind the anode of a vacuum diode“. Technical Physics Letters 48, Nr. 2 (2022): 47. http://dx.doi.org/10.21883/tpl.2022.02.53580.19053.

Der volle Inhalt der Quelle

Annotation:

The parameters of a high-current electron beam extracted from the self-focusing zone through a hole in the anode into a vacuum chamber are investigated. The beam parameters were determined from the measurement of the spatial distribution of destruction and glow arising in polymethyl methacrylate samples installed at different distances from the anode (electron beam autographs). The formation of two electron beams --- a self-focused with a high energy density, propagating along the axis of the cone facing the base to the anode with an apex angle of ~ 7o and a high-energy beam of low density, propagating in a hollow truncated cone and surrounding self-focused, was found. The oscillograms of the current and the energy of the electron beams were measured. Keywords: vacuum diode, electron beam, filamentation, self-focusing, polymethyl methacrylate, destruction, glow, high current pulsed electron beam

APA, Harvard, Vancouver, ISO und andere Zitierweisen

46

Cox, Barry, und James Hill. „Carbon Nanocones with Curvature Effects Close to the Vertex“. Nanomaterials 8, Nr. 8 (17.08.2018): 624. http://dx.doi.org/10.3390/nano8080624.

Der volle Inhalt der Quelle

Annotation:

The conventional rolled-up model for carbon nanocones assumes that the cone is constructed from a rolled-up graphene sheet joined seamlessly, which predicts five distinct vertex angles. This model completely ignores any effects due to the changing curvature, and all bond lengths and bond angles are assumed to be those for the planar graphene sheet. Clearly, curvature effects will become more important closest to the cone vertex, and especially so for the cones with the smaller apex angles. Here, we construct carbon nanocones which, in the assembled cone, are assumed to comprise bond lengths and bond angles that are, as far as possible, equal throughout the structure at the same distance from the conical apex. The predicted bond angles and bond lengths are shown to agree well with those obtained by relaxing the conventional rolled-up model using Lammps software (version: 11 September 2008). The major objective here is not simply to model physically realisable carbon nanocones for which numerical procedures are far superior, but rather, to produce an improved model that takes curvature effects close to the vertex into account, and from which we may determine an analytical formula which represents an improvement on the conventional rolled-up model.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

47

Mushtaq, Nasir, Syeda Shamal, Nayab Hassan, Jawad Ullah Shah und Haider Ali. „Comparison of Prognostic Indicators of Maxillary Impacted Canine using OPG (Orthopantomogram) with CBCT (Cone Beam Computed Tomography)“. Journal of Gandhara Medical and Dental Science 9, Nr. 2 (06.04.2022): 23–28. http://dx.doi.org/10.37762/jgmds.9-2.279.

Der volle Inhalt der Quelle

Annotation:

OBJECTIVES: The aim of the present study was to compare OPG (orthopantomogram) in locating impacted canines with CBCT (cone beam computed tomography) scans of the same patients. METHODOLOGY: The cross-sectional study was carried out on the OPG (orthopantomogram) and CBCT (Cone-Beam Computed Tomography) of 27 patients (17 females and 10 males) presenting with impacted permanent maxillary canines. Thirty-five impacted canines were subsequently assessed on the four guidelines devised by McSherry and Pitt and applied to the panoramic films and CBCT scans. RESULTS: The results show weak agreement for the canine’s angle to the midline and the canine’s horizontal root apex position (k value=0.55, 0.46, respectively). Moreover, significant differences were found between the OPG (orthopantomogram) and the CBCT (Cone-Beam Computed Tomography) for all the variables using Chi-square and Fisher’s exact test (p=.000) CONCLUSION: The results showed a significant difference in the 2D and 3D images of impacted maxillary canines, which can produce different diagnoses, and therefore treatment plans. OPG (Orthopantomogram) cannot be completely relied upon for the routine diagnosis of impacted canines.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

48

Шалаев, O. Shalaev, Некрылов, D. Nekrylov, Селина und Olesya Selina. „The analysis of treatment results of chronic apical periodontitis“. Journal of New Medical Technologies. eJournal 8, Nr. 1 (05.11.2014): 1–4. http://dx.doi.org/10.12737/4797.

Der volle Inhalt der Quelle

Annotation:

Forms of chronic periodontitis, treatment results and long-term results are traditionally defined on the basis of X-ray examination. Today, the most modern and reliable method for diagnostic X-ray examination opportunities in dentistry is dental cone-beam computed tomography. In comparison with other methods of X-ray examination in dentistry the method of dental cone-beam computed tomography has a number of advantages: the ability to make measurements of distances, the density of solid tissue, angles and areas in any part of the data at any angle, at any height, length, width up to 0,125 mm due to the fact that the area research scan 1 to 1; working image can be enlarged, moved, inverted, modified for clarity, brightness and contrast. dental cone-beam computed tomography method allows to detect the position, shape, sizes, construction of various structures to determine their topographic anatomic relations with other organs, and tissues. The analysis of the study results of treatment of apical periodontitis in this view doesn’t give a complete picture of the selected comparative method of treatment, which is the foundation for a thorough study of the density of tissue in the apex of the teeth in the long-term period (3-6-12 months). Experience in the use of dental computer tomography showed that it is possible to assess of the areas of destructive changes of the periapical region and periodontal tissues in most cases than traditional x-ray techniques.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

49

KAMEDA, Takatsugu, Tetsuya SUMIDA, Shinsuke MOCHIZUKI und Hideo Osaka. „G703 Flow around a Cone placed in a Thin Turbulent Boundary Layer : Variation of a Pressure Distribution on the Surface to the Apex Angle of a Cone“. Proceedings of the Fluids engineering conference 2009 (2009): 601–2. http://dx.doi.org/10.1299/jsmefed.2009.601.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

50

SAHARIAN, A. A. „FERMIONIC CONDENSATE AND INDUCED CURRENT IN A CONICAL SPACE WITH A CIRCULAR BOUNDARY AND MAGNETIC FLUX“. International Journal of Modern Physics: Conference Series 14 (Januar 2012): 496–500. http://dx.doi.org/10.1142/s2010194512007623.

Der volle Inhalt der Quelle

Annotation:

The fermionic condensate and current density are investigated in a (2 + 1)-dimensional conical spacetime in the presence of a circular boundary and a magnetic flux. On the boundary the fermionic field obeys the MIT bag boundary condition. For irregular modes, we consider a special case of boundary conditions at the cone apex, when the MIT bag boundary condition is imposed at a finite radius, which is then taken to zero. The condensate and current are periodic functions of the magnetic flux with the period equal to the flux quantum. For both exterior and interior regions, the expectation values are decomposed into boundary-free and boundary-induced parts. In the case of a massless field the boundary-free part in the vacuum expectation value of the charge density vanishes, whereas the presence of the boundary induces nonzero charge density. At distances from the boundary larger than the Compton wavelength of the fermion particle, the condensate and current decay exponentially, with the decay rate depending on the opening angle of the cone.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Zeitschriftenartikel zum Thema „APEX ANGLE OF THE CONE“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an