scholarly journals Formation of inner rings in 3D potentials of barred galaxies

2004 ◽  
Vol 220 ◽  
pp. 275-276
Author(s):  
Panos A. Patsis ◽  
Charalampos Skokos ◽  
E. Athanassoula
Keyword(s):  
Periodic Orbits ◽  
Major Axis ◽  
Minor Axis ◽  
Barred Galaxies ◽  
High Energies ◽  
Families Of Periodic Orbits ◽  
Two Sides ◽  
Analytic Potential

In a 3D analytic potential we find the families of periodic orbits that support the formation of inner rings. These are families at high energies, between the inner radial ultraharmonic 4:1 (iUHR) resonance and corotation, influenced by the 4:1, 6:1 and 8:1 resonances. the inner rings they support are mainly ovals and polygons with ‘corners’ on the bar minor axis, on its sides, which correspond to morphologies often seen in real galaxies like NGC 6782 and IC 4290. We also investigate the conditions under which less probable shapes of rings may be supported by orbits at the region. Such rings include pentagonal features (NGC 3367) and hexagons with cusps on the major axis of the bar and two sides parallel to it (NGC 7020).

First-order resonant in periodic orbits

2020 ◽  
Vol 18 (01) ◽  
pp. 2150011
Author(s):  
Bhavika M. Patel ◽  
Niraj M. Pathak ◽  
Elbaz I. Abouelmagd
Keyword(s):  
Periodic Orbits ◽  
Major Axis ◽  
Initial Position ◽  
Jacobi Constant ◽  
Semi Major Axis ◽  
First Order ◽  
Resonant Orbits ◽  
Oblate Body ◽  
Families Of Periodic Orbits ◽  
Frame Work

In the frame work of Saturn–Titan system, the resonant orbits of first-order are analyzed for three different families of periodic orbits, namely, interior resonant orbits, exterior resonant orbits and [Formula: see text]-Family orbits. This analysis is developed by considering Saturn as a spherical and oblate body. The initial position, semi-major axis, eccentricity, orbital period and order of resonant orbits of these families are investigated for different values of Jacobi constant and oblateness parameter.

Design of Turning Area for LNG Terminal Base on Computer Simulation

2012 ◽  
Vol 215-216 ◽  
pp. 1236-1240
Author(s):  
Yao Tian Fan
Keyword(s):  
Computer Simulation ◽  
Theoretical Calculation ◽  
Cost Effective ◽  
Major Axis ◽  
Minor Axis ◽  
Computer Simulator

Design of turning area for sea port is generally done according to the outcome of theoretical calculation or real-ship trial. However, these methods only take into account some limited respects for planning a port or are not so cost-effective. In this paper, computer simulator is used for optimizing the size of turning area for Yangshan LNG terminal. The outcome indicates that the major axis and minor axis of the turning area can meet the requirement of Q-Max LNG carrier berthing operation and it is suggested to do such maneuvering in some given conditions related to wind, current, tide, visibility and wave.

Effect of Mach number on the acoustic field of 2:1 elliptic-slot jet

2001 ◽  
Vol 105 (1043) ◽  
pp. 9-16 ◽  
Author(s):  
S. B. Verma ◽  
E. Rathakrishnan
Keyword(s):  
Mach Number ◽  
Fundamental Frequency ◽  
Acoustic Field ◽  
Major Axis ◽  
Shock Structure ◽  
Minor Axis ◽  
Noise Levels ◽  
Underexpanded Jets ◽  
Barrel Shock ◽  
Mach Numbers

Abstract The shock-structure and the related acoustic field of underexpanded jets undergoes significant changes as the Mach number Mj is increased. The present investigation is carried out to study the effect of Mach number on an underexpanded 2:1 elliptic-slot jet. Experimental data are presented for fully expanded Mach numbers ranging from 1.3 to 2.0. It is observed that the ‘cross-over’ point at the end of the first cell at low Mach numbers gets replaced by a normal shock at a highly underexpanded condition resulting in the formation of a ‘barrel’ shock along the minor-axis side with a ‘bulb’ shock formed along the major-axis side. The above change in shock structure is accompanied by a related change in the acoustic field. The amplitude of fundamental frequency along the minor-axis side grows with Mj but falls beyond Mj = 1.75. Along the major-axis side, however, the fundamental frequency does not exist at low Mach numbers. It appears at Mj = 1.75 but then falls at Mj = 2.0. The related azimuthal directivity of overall noise levels (OASPL) shows significant changes with Mj.

Comparison of the Flame Characteristics of Turbulent Circular and Elliptic Jets in a Crossflow

2002 ◽  
Vol 124 (3) ◽  
pp. 197-203 ◽  
Author(s):  
S. R. Gollahalli ◽  
D. Pardiwalla
Keyword(s):  
Flame Structure ◽  
Flux Ratio ◽  
Major Axis ◽  
Minor Axis ◽  
No Production ◽  
Sampling System ◽  
Computer Data ◽  
Rate Of Increase ◽  
Jet Velocity ◽  
Lower Limits

This study was directed to understand the coupling effects of the noncircular geometry of the burner and a crossflow on the combustion of gas jets. This paper compares the characteristics of turbulent propane jet flames from circular (diameter=0.45 cm) and elliptic (major axis/minor axis=3) burners of equivalent exit area in a crossflow. The elliptic burner was oriented with its major axis or minor axis aligned with the crossflow. Experiments were conducted in a wind tunnel provided with optical and probe access and capable of wind speeds up to 12.5 m/s. The burners were fabricated with metal tubes. Instrumentation included a Pt-Pt/13% Rh thermocouple, a quartz-probe gas sampling system, chemiluminescent and nondispersive infrared analyzers, a video-recorder, and a computer data acquisition system. The measurements consisted of the upper and lower limits of jet velocity for a stable flame, flame configuration, and visible length. Flame structure data including temperature profiles and concentration profiles of CO2,O2, CO, and NO were obtained in a two-zone flame configuration (at jet to crossflow momentum flux ratio=0.11), where a planar recirculation exists in the wake of the burner tube followed by an axisymmetric tail. The relative emission indicators of CO and NO were estimated from the composition data. Results show that the upper and lower limits of the fuel jet velocity increase with the crossflow velocity for all burners, and the rate of increase is highest for the elliptic burner with its minor axis aligned with the crossflow. That burner configuration also produces the longest flame. The relative emission indicators show that the CO production is lower and NO production is higher with elliptic burners than with circular burners in crossflow.

Quantitative diagenetic analyses of Edmontosaurus regalis (Dinosauria: Hadrosauridae) postcranial elements from the Danek Bonebed, Upper Cretaceous Horseshoe Canyon Formation, Edmonton, Alberta, Canada: implications for allometric studies of fossil organisms

2014 ◽  
Vol 51 (11) ◽  
pp. 1007-1016 ◽  
Author(s):  
Mackenzie Baert ◽  
Michael E. Burns ◽  
Philip J. Currie
Keyword(s):  
Cross Section ◽  
Upper Cretaceous ◽  
Strong Relationship ◽  
Major Axis ◽  
Minor Axis ◽  
Morphological Features ◽  
Fossil Assemblages ◽  
Fossil Vertebrate ◽  
Horseshoe Canyon Formation ◽  
Upper Campanian

For fossil assemblages, quantitative size and shape studies are often complicated by diagenetic distortion. Different vertebrate elements, although subjected to similar burial stresses, exhibit deformations based upon their original shapes; this hypothesis is tested here by quantitatively comparing deformed humeri and femora from the Danek Bonebed (a monodominant Edmontosaurus regalis bonebed from the upper Campanian Horseshoe Canyon Formation in Edmonton, Alberta, Canada) with samples of undeformed humeri and femora from modern and fossil assemblages. Analyses suggest that at the Danek Bonebed a strong relationship exists between element length and circumference despite being distorted by crushing deformation. Major and minor axes of the midshaft cross section, however, were not uniformly distorted. Although their anatomical position did not change, the major axis became longer relative to the minor axis in distorted specimens. A regression based on the undeformed humeri was not able to accurately predict circumference in the Danek humeri. Further study might quantify the deformation of other bones in the Danek Bonebed and could be extended to other assemblages and genera. Caution should be taken when conducting studies in which diagenetic crushing may have altered morphological features of fossil vertebrate remains.

scholarly journals Effect of soaking process on physical properties of mature pepper berries (Piper nigrum L.)

Food Research ◽  
2020 ◽  
Vol 4 (S1) ◽  
pp. 116-123
Author(s):  
A.A.P.N. Megat ◽  
Rosnah Shamsudin ◽  
H. Che Man ◽  
M.E. Ya'acob
Keyword(s):  
Physical Properties ◽  
Water Uptake ◽  
Major Axis ◽  
Minor Axis ◽  
Piper Nigrum ◽  
Uptake Ratio ◽  
Fracture Force ◽  
Brown Colour

This study was carried out to determine the effect of the soaking process on the physical properties of the mature pepper berries. The soaking process was conducted by immersing pepper berries in water. The results showed the dimensions of the pepper berries before soaking was 5.24 mm (minor axis), 5.57 mm (medium axis) and 5.61 mm (major axis). The weight of pepper berries increased from day 1 (13.58%) until day 3 (16.92%) and decreased after day 4 (0.77%) until day 7 of soaking (13.08%). The water uptake ratio of soaked pepper berries increased from 1.14% (day 1) until 1.17% (day 3) and then decreased from 1.01% (day 4) until 0.87% (day 7). The fracture force required to fracture the pericarp was decreased starting from 67.21 N (day 1) decreased until 21.40 N (day 7). The colour of mature pepper berries was changed into black-brown colour (L= 34.16, a= 1.38, b= 1.40).

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