scholarly journals The properties of torsional vibrations in reciprocating engine shafts. —Part II

1926 ◽  
Vol 113 (764) ◽  
pp. 272-281 ◽  
Keyword(s):  
Moment Of Inertia ◽  
Experimental Results ◽  
Effective Length ◽  
Torsional Vibrations ◽  
Static Tests ◽  
Reciprocating Engine ◽  
The Mean ◽  
The Moment

In order to compare with the experimental results, the algebraic values of the results just obtained will be converted into numbers, using the dimensions adopted in the experiment. The shaft used was a steel rod ⅜-inch in diameter. From the contact of fly-wheel A to that of fly-wheel E was 78¾ inches, and from fly-wheel A to the crank (see fig. 1) was 81¼ inches. The mean of these, or 80 inches, was takenas the effective length. The modulus of rigidity, taken from static tests, was found to be 11.4 x 10 6 lbs. per square inch. The moment of inertia of fly-wheel A was about 15,000 lbs. (inches) 2 . The fly-wheel E was tested experimentally, and its moment of inertia found to be 194·2 lbs. (inches) 2 . The crank radius, a , was 2 inches.

The Inertial Effect in Rotational Fluorescence Depolarization

1992 ◽  
Vol 47 (9) ◽  
pp. 971-973 ◽  
Author(s):  
A. Kawski ◽  
P. Bojarski ◽  
A. Kubicki
Keyword(s):  
Empirical Equation ◽  
Molecular Geometry ◽  
Moment Of Inertia ◽  
Experimental Results ◽  
Inertial Effect ◽  
Fluorescence Depolarization ◽  
Moments Of Inertia ◽  
Low Viscosity ◽  
The Moment ◽  
Semi Empirical

Abstract The influence of the moment of inertia on the rotational fluorescence depolarization is discussed. Based on experimental results obtained for five luminescent compounds: 2,5-diphenyloxazole (PPO), 2,2'-p-phenylene-bis(5-phenyloxazole) (POPOP), p-bis[2-(5-α-naphthyloxazolyl)]-benzene (α-NOPON), 4-dimethylamino-ω-methylsulphonyl-trans-styrene (3a) in n-parafines at low viscosity (from 0.22 x 10-3 Pa • s to 0.993 x 10-3 Pa • s) and diphenylenestilbene (DPS) in different solvents, a semi-empirical equation is proposed, yielding moments of inertia that are only two to five times higher than those estimated from the molecular geometry

scholarly journals Mean curvature effect on the response and failure of round-hole tubes submitted to cyclic bending

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110622
Author(s):  
Kuo-Long Lee ◽  
Yu-Chun Tsai ◽  
Wen-Fung Pan
Keyword(s):  
Mean Curvature ◽  
Hole Diameter ◽  
Experimental Results ◽  
Round Hole ◽  
Curvature Effect ◽  
Cyclic Bending ◽  
The Mean ◽  
The Moment ◽  
Straight Lines ◽  
Minimum Curvature

This paper presents an experiment and analysis to investigate the response and failure of 6061-T6 aluminum alloy round-hole tubes with different hole diameters of 2, 4, 6, 8, and 10 mm subjected to cyclic bending at different curvature ratios of −1.0, −0.5, 0.0, and +0.5. The curvature ratio is defined as the minimum curvature divides by the maximum curvature. Four different curvature ratios are employed to highlight the mean curvature effect. It can be seen from the experimental results that the moment-curvature relationships gradually relax and become steady states after a few bending cycles for curvature ratios of −0.5, 0.0, and +0.5. The ovalization-curvature relationship depicts an asymmetrical, ratchetting and increasing as the number of bending cycles increases for all curvature ratios. In addition, for each hole diameter, the relationships between the curvature range and the number of bending cycles necessary to initiate failure on double logarithmic coordinates display four almost-parallel straight lines for four different curvature ratios. Finally, this paper introduces an empirical formula to simulate the above relationships. By comparing with experimental results, the analysis can reasonably describe the experimental results.

Moments of Inertia of Bat Wings and Body

1991 ◽  
Vol 158 (1) ◽  
pp. 19-35 ◽  
Author(s):  
MIKAEL THOLLESSON ◽  
ULLA M. NORBERG
Keyword(s):  
Body Mass ◽  
Shoulder Joint ◽  
Mean Value ◽  
The Body ◽  
Moment Of Inertia ◽  
Moments Of Inertia ◽  
Wing Span ◽  
The Mean ◽  
Roll Axis ◽  
The Moment

The moments of inertia of the wings about the shoulder joint and about the roll axis were estimated in eight species of bats, using strip analysis. The moment of inertia of the bat's trunk about the roll axis was estimated by assuming the body and head to be ellipsoids. The slopes of the regressions of moment of inertia of one wing about the shoulder joint (Jw) versus body mass (mtot), wing span (b) and wing area (S) were as expected for geometrically similar animals of different size. The exponent for Jwversus body mass in bats deviates from that found for birds, while the exponent for Jw versus wing span does not. A multiple regression was used to show that Jw may be estimated by: J w = 4.49 × 10−3mtot0.53b2.15S0.65. The mean value of the moment of inertia originating from the trunk is 7 % of the bat's total moment of inertia (of wings and body combined) about the roll axis. The mass of one wing (mw) was plotted against body mass for the eight bat species, which gives: m w = 0.112mtot1 11. The slope for our bats, 1.11, is similar to that obtained for birds, 1.10. Adaptations to reduce the moments of inertia may be more important for increasing a bat's flight agility (roll acceleration) than for decreasing the total mechanical power required to fly. The influences of wing moment of inertia and wing shape on manoeuvrability and agility are discussed.

THE EVOLUTION PROPERTIES OF EVEN–EVEN 100-110Pd NUCLEI

2012 ◽  
Vol 21 (12) ◽  
pp. 1250101 ◽  
Author(s):  
I. M. AHMED ◽  
HEWA Y. ABDULLAH ◽  
S. T. AHMAD ◽  
I. HOSSAIN ◽  
M. K. KASMIN ◽  
...  
Keyword(s):  
Rotational Energy ◽  
Moment Of Inertia ◽  
Experimental Results ◽  
Interacting Boson Model ◽  
Gamma Energy ◽  
Boson Model ◽  
The Moment

The properties of the yrast states for 100-110 Pd even–even (e–e) nuclei have been established. The relation between the moment of inertia 2ϑ/ℏ2 and the square of the rotational energy (ℏω)2 has been drawn to identify the back-bending that may occur at a certain state for each isotope. The relation between gamma-energy over spin Eγ/I as a function of spin I has been drawn to determine the evolution in each isotope ranging from vibration to rotational properties. The suitable limit in the interacting boson model IBM-1 has been used to calculate the yrast states for each isotope, which are then compared with the experimental results.

Deformability of discs in turbulence

2021 ◽  
Vol 933 ◽  
Author(s):  
Gautier Verhille
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Turbulent Flows ◽  
Moment Of Inertia ◽  
Inertia Tensor ◽  
Experimental Results ◽  
Bending Modulus ◽  
The Moment ◽  
Qualitative Argument

The aim of this study is to investigate experimentally the transition from a rigid regime to a deformed regime for flexible discs freely advected in turbulent flows. For a given disc, the amplitude of the deformation is expected to increase when its bending modulus decreases or when the turbulent kinetic energy increases. To quantify this qualitative argument, experiments are performed where the deformation of flexible discs is measured using three cameras. The amplitude of the deformation has been characterised by the eigenvalues of the moment of inertia tensor. Experimental results exhibit a transition from a rigid regime to a deformed regime that depends on the size, the density and the flexibility of the disc and the turbulent kinetic energy. The modelling of this transition is a generalisation and an extension of the previous models used to characterise the deformation of flexible fibres in turbulent flows.

Perception of the moment of inertia of hand tools

1982 ◽  
Author(s):  
Carol Zahner ◽  
M. Stephen Kaminaka
Keyword(s):  
Moment Of Inertia ◽  
Hand Tools ◽  
The Moment

Research on the identification of the moment of inertia of PMSM for industrial robots

2020 ◽  
Author(s):  
Chuanwen Zhang ◽  
Guangxu Zhou ◽  
Ting Yang ◽  
Ningran Song ◽  
Xinli Wang ◽  
...  
Keyword(s):  
Industrial Robots ◽  
Moment Of Inertia ◽  
The Moment

scholarly journals Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton
Keyword(s):  
Main Sequence ◽  
Open Clusters ◽  
Main Sequence Stars ◽  
Spectroscopic Analyses ◽  
Solar Metallicity ◽  
Metal Abundances ◽  
The Mean ◽  
The Moment ◽  
The One ◽  
Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

scholarly journals Contour Detection for Fibre of Preserved Szechuan Pickle Based on Dilated Convolution

2019 ◽  
Vol 9 (13) ◽  
pp. 2684 ◽  
Author(s):  
Hongyang Li ◽  
Lizhuang Liu ◽  
Zhenqi Han ◽  
Dan Zhao
Keyword(s):  
Edge Detection ◽  
State Of The Art ◽  
Contour Detection ◽  
Experimental Results ◽  
Contour Method ◽  
Class Differences ◽  
Dilated Convolution ◽  
The Mean ◽  
Art Performance

Peeling fibre is an indispensable process in the production of preserved Szechuan pickle, the accuracy of which can significantly influence the quality of the products, and thus the contour method of fibre detection, as a core algorithm of the automatic peeling device, is studied. The fibre contour is a kind of non-salient contour, characterized by big intra-class differences and small inter-class differences, meaning that the feature of the contour is not discriminative. The method called dilated-holistically-nested edge detection (Dilated-HED) is proposed to detect the fibre contour, which is built based on the HED network and dilated convolution. The experimental results for our dataset show that the Pixel Accuracy (PA) is 99.52% and the Mean Intersection over Union (MIoU) is 49.99%, achieving state-of-the-art performance.

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