XI.—Correlations in alpha-Particle-accompanied fission

1971 ◽  
Vol 69 (2) ◽  
pp. 149-164
Author(s):  
N. Feather
Keyword(s):  
Kinetic Energy ◽  
Single Mode ◽  
Neutron Number ◽  
Particle Energy ◽  
Ternary Fission ◽  
Classical Description ◽  
Independent Variables ◽  
The Moment ◽  
Electrostatic Potential Energy ◽  
Nuclear Configuration

SynopsisThe attempt is made to exhibit the necessary correlations between fragment excitation (or prompt neutron number), fragment kinetic energy, and a-particle energy, in α-particle-accompanied ternary fission. Treating a single mode of mass and charge division on the assumption that the ternary process develops directly out of an intermediate binary phase, and using the mutual electrostatic potential energy of the nascent binary fragments of this phase and the additional kinetic energy developed at the moment of α-particle emission as independent variables, various formal results are obtained and discussed in the light of the experimental evidence.In terms of a classical description, it appears likely that (for a given mode of division) the nuclear configuration at a-particle release in ternary fission is subject to much smaller variations than is the nuclear configuration at scission in binary fission in the corresponding mode. Possible inadequacies of this classical description are very briefly discussed.

19.—Calculations relative to the Experimental Observation of the Products of Disintegration of 5He liberated as a Light Particle in Ternary Fission

1973 ◽  
Vol 71 (3) ◽  
pp. 233-248
Author(s):  
N. Feather ◽  
D. G. Vass
Keyword(s):  
Energy Spectrum ◽  
Kinetic Energy ◽  
Light Particle ◽  
Ternary Fission ◽  
Centre Of Mass ◽  
Considerable Difficulty ◽  
Simple Evaluation ◽  
The Moment ◽  
Made In ◽  
Α Particles

SynopsisThere is now strong evidence, from observations of directional correlation between the α-particles and neutrons of fission, for the release of 5He as a neutron-unstable light particle with a frequency of a few per 104 low-energy fission events (Cheifetz et al. 1972).Because the energy spectrum of the neutrons liberated in the disintegration of 5He particles travelling with a fixed kinetic energy is a rectangular spectrum (assuming isotropy of disintegration directions in the centre-of-mass space), it is in principle possible to deduce the kinetic energy spectrum characterising the 5He particles of ternary fission at the moment of disintegration from the energy spectrum of the liberated neutrons.Detailed calculations have been made in relation to the limitations of actual experimental arrangements with regard to this possibility. These limitations are shown to be severe—not least in respect of statistical accuracy. Indeed, it is shown that considerable difficulty attaches to the ‘simple’ evaluation of the 5He/4He ratio (which Cheifetz et al. estimate as 1 :(8 ± 2) for 252Cf, for α-particles of energy greater than 9 MeV).An instrumental cause is suggested for the maximum reported by Cheifetz et al. in the energy spectrum ascribed to the 5He disintegration neutrons.

scholarly journals Characteristics, Energetics, and Origins of Agulhas Current Meanders and Their Limited Influence on Ring Shedding

2015 ◽  
Vol 45 (9) ◽  
pp. 2294-2314 ◽  
Author(s):  
Shane Elipot ◽  
Lisa M. Beal
Keyword(s):  
Kinetic Energy ◽  
Single Mode ◽  
Cyclonic Circulation ◽  
Recent Analysis ◽  
Altimeter Data ◽  
Western Boundary ◽  
Mean Flow ◽  
Current Time ◽  
Agulhas Current ◽  
The Mean

AbstractThe Agulhas Current intermittently undergoes dramatic offshore excursions from its mean path because of the downstream passage of mesoscale solitary meanders or Natal pulses. New observations and analyses are presented of the variability of the current and its meanders using mooring observations from the Agulhas Current Time-Series Experiment (ACT) near 34°S. Using a new rotary EOF method, mesoscale meanders and smaller-scale meanders are differentiated and each captured in a single mode of variance. During mesoscale meanders, an onshore cyclonic circulation and an offshore anticyclonic circulation act together to displace the jet offshore, leading to sudden and strong positive conversion of kinetic energy from the mean flow to the meander via nonlinear interactions. Smaller meanders are principally represented by a single cyclonic circulation spanning the entire jet that acts to displace the jet without extracting kinetic energy from the mean flow. Synthesizing in situ observations with altimeter data leads to an account of the number of mesoscale meanders at 34°S: 1.6 yr−1 on average, in agreement with a recent analysis by Rouault and Penven (2011) and significantly less than previously understood. The links between meanders and the arrival of Mozambique Channel eddies or Madagascar dipoles at the western boundary upstream are found to be robust in the 20-yr altimeter record. Yet, only a small fraction of anomalies arriving at the western boundary result in meanders, and of those, two-thirds can be related to ring shedding. Most Agulhas rings are shed independently of meanders.

Shell and odd-even effects on alpha-particle energy spectra from the (p,α) reaction on nuclei around neutron number 50

1987 ◽  
Vol 35 (2) ◽  
pp. 467-478 ◽  
Author(s):  
I. Kumabe ◽  
Y. Mito ◽  
M. Hyakutake ◽  
N. Koori ◽  
H. Sakai ◽  
...  
Keyword(s):  
Alpha Particle ◽  
Neutron Number ◽  
Particle Energy ◽  
Energy Spectra ◽  
Alpha Particle Energy

scholarly journals Readiness in Retirement Life

2020 ◽  
Vol 76 ◽  
pp. 01004
Author(s):  
Dewi Astuti
Keyword(s):  
Old Age ◽  
Purpose In Life ◽  
Educational Background ◽  
Life Goals ◽  
Independent Variables ◽  
Pension Program ◽  
Study Population ◽  
Independent Variable ◽  
The Moment ◽  
Variable Focus

This study investigates whether the ownership of a retirement program is owned only by those who have a purpose in life in old age or also owned by those who focus on working well now and do not have a purpose in life in old age. The study population is employees, and entrepreneurs who have worked, with sample criteria have a steady income with a specific educational background. The number of samples is 52 respondents. The result revealed that having the purpose of life in old age, and focusing on the purpose of life at the moment encourage someone to have a pension program. The results of the study stated that the effect of the independent variables on the dependent variable appeared weak. The independent variable "has the purpose of old age life" and the independent variable "focus on life goals current" can explain 0.69 % of the dependent variable "has retirement fund program.

Some measurements of the flux of infra-red radiation in the atmosphere

1956 ◽  
Vol 236 (1205) ◽  
pp. 175-186 ◽  
Keyword(s):  
Kinetic Energy ◽  
Lower Stratosphere ◽  
Atmospheric Radiation ◽  
Radiative Cooling ◽  
Classical View ◽  
Upper Troposphere ◽  
Infra Red ◽  
The Moment ◽  
Effective Radiation ◽  
Red Radiation

For the continual development of the kinetic energy of the winds, it is necessary for the upper troposphere to be cooled by radiation. Results are reported of nine aircraft ascents on which the upward and downward flows of infra-red radiation were measured and com­pared with values calculated using the radiation charts of Elsasser and Yamamoto. The divergence of radiative flux deduced from these measurements clearly shows that the cooling in the troposphere is not very different from that calculated from radiation charts. The importance of clouds on the radiative pattern is demonstrated; at the moment, incom­plete knowledge of cloud structure will be the chief factor limiting the value of calculations of atmospheric radiation. The measurements are of very limited value in the stratosphere, since, for the very small quantities of water there, the effective radiation is in the rotation band of water vapour ( λ between 30 and 70 μ ) and the radiometer used was not sensitive to these wavelengths. If the use of radiation charts is extrapolated to these conditions they indicate that the radiative cooling continues in the lower stratosphere. This is in contrast with the ‘classical’ view that the stratosphere is in radiative equilibrium.

scholarly journals Simulation of Bullet Fragmentation and Penetration in Granular Media

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5243
Author(s):  
Froylan Alonso Soriano-Moranchel ◽  
Juan Manuel Sandoval-Pineda ◽  
Guadalupe Juliana Gutiérrez-Paredes ◽  
Usiel Sandino Silva-Rivera ◽  
Luis Armando Flores-Herrera
Keyword(s):  
Kinetic Energy ◽  
Granular Media ◽  
Elastic Collision ◽  
Smooth Particle Hydrodynamics ◽  
X Ray ◽  
Bullet Fragmentation ◽  
Particle Hydrodynamics ◽  
The Moment ◽  
Physical Phenomena ◽  
The Impact

The aim of this work is to simulate the fragmentation of bullets impacted through granular media, in this case, sand. In order to validate the simulation, a group of experiments were conducted with the sand contained in two different box prototypes. The walls of the first box were constructed with fiberglass and the second with plywood. The prototypes were subjected to the impact force of bullets fired 15 m away from the box. After the shots, X-ray photographs were taken to observe the penetration depth. Transient numerical analyses were conducted to simulate these physical phenomena by using the smooth particle hydrodynamics (SPH) module of ANSYS® 2019 AUTODYN software. Advantageously, this module considers the granular media as a group of uniform particles capable of transferring kinetic energy during the elastic collision component of an impact. The experimental results demonstrated a reduction in the maximum bullet kinetic energy of 2750 J to 100 J in 0.8 ms. The numerical results compared with the X-ray photographs showed similar results demonstrating the capability of sand to dissipate kinetic energy and the fragmentation of the bullet caused at the moment of impact.

scholarly journals Magnetic Field Amplification and Polar Jet Formation in Protostars

1987 ◽  
Vol 115 ◽  
pp. 384-384
Author(s):  
S. Hinata
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Kinetic Energy ◽  
Accretion Disk ◽  
Outer Edge ◽  
Moment Of Inertia ◽  
Simple Relationship ◽  
Field Amplification ◽  
Background Magnetic Field ◽  
The Moment

There is a simple relationship among moment of inertia I, rotational kinetic energy K, and momentum L given by (David Layzer, private communication), 2IK ≧ L. During the Hayashi phase a rotating protostar will amplify the trapped magnetic field by a dynamo-like process. Since the rotation is expected to be fast, many unstable modes will be excited and will grow exponentially in time until some nonlinear processes saturate the amplitude. However, it may happen that the reduction in rotational kinetic energy becomes so large that without increasing the moment of inertia the inequality given above may not be satisfied. The only way to increase the moment of inertia is to move the mass outward. This can be done by transferring the angular momentum outward through the magnetic field. So we will have a fast rotating mass shell at the outer edge of the star. Further transfer of angular momentum will push the shell against the accretion disk; the moving masses of the disk will divert the mass flow along the background magnetic field which extends perpendicular to the accretion disk. This results in the hollow cone jets from both poles because the outward motion is primarily on the equatorial plane.

The kinetic energy of fragments and alpha particles in the ternary fission of U235

1964 ◽  
Vol 15 (1) ◽  
pp. 659-663
Author(s):  
V. N. Dmitriev ◽  
K. A. Petrzhak ◽  
Yu. F. Romanov
Keyword(s):  
Kinetic Energy ◽  
Alpha Particles ◽  
Ternary Fission

New perspective of Grodzins E × B(E2) ↑ product rule

2018 ◽  
Vol 27 (04) ◽  
pp. 1850033 ◽  
Author(s):  
J. B. Gupta ◽  
Vikas Katoch
Keyword(s):  
Nuclear Structure ◽  
Transition Probability ◽  
Neutron Number ◽  
Level Energy ◽  
Product Rule ◽  
Atomic Nuclei ◽  
Number Formula ◽  
Energy Formula ◽  
New Perspective ◽  
The Moment

In the collective spectra of atomic nuclei, the level energy [Formula: see text] varies with atomic number [Formula: see text] and neutron number [Formula: see text]. Also the [Formula: see text]2 decay-reduced transition probability [Formula: see text] is related to the energy [Formula: see text]. The product [Formula: see text] is constant according to Grodzins product rule, independent of the vibration or rotational status of the nucleus. The product rule is often used for determining [Formula: see text] from the known [Formula: see text]. However, the variation of the product with various parameters is also suggested in the literature. Hence, a detailed global study of this rule for [Formula: see text] region is warranted. We use a novel method of displaying the linear relation of [Formula: see text] with [Formula: see text] for the isotopes of each element (Xe–Pt), instead of their variation with [Formula: see text] or [Formula: see text]. Through our work, we firmly establish the global validity of the Grodzins relation of [Formula: see text], being proportional to the moment of inertia, except for the deviation in specific cases. Our [Formula: see text] versus [Formula: see text] plots provide a transparent view of the variation of the low-energy nuclear structure. This gives a new perspective of their nuclear structure. Also the various theoretical interpretations of [Formula: see text]s and the energy [Formula: see text] are reviewed.

Plane stress theories

1967 ◽  
Vol 63 (4) ◽  
pp. 1369-1378 ◽  
Author(s):  
F. P. Sayer ◽  
C. C. Calder
Keyword(s):  
Plane Stress ◽  
Elastic Plates ◽  
Moment Equations ◽  
The Real ◽  
Independent Variables ◽  
The Moment ◽  
A Minor ◽  
Fundamental Equations ◽  
Modified Forms ◽  
Modified Theory

Tiffen and Lowe in two recent papers (4,5) have developed exact theories for the bending and stretching of generally loaded elastic plates using the moments of the fundamental equations of infinitesimal elasticity. The two theories depend on the choice of independent variables so that a pair of functions, denoted by and are independent. The choice is correct in (4) but not in (5). This paper pro-poses a modification to the forms of the functions and in (5) and then shows that the modified forms are independent. The subsequent alteration to (5), as will be seen, involves only the biharmonic function χ Apart from a minor algebraic adjustment the rest of the theory, containing the real and complex eigenfunctions and particular integral, is preserved. It should be noted that the modified theory like the original is obtained entirely from the moment equations.

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