In-Plane Vibrations of Thick Circular Rings With T or I Cross Sections

1979 ◽  
Vol 46 (2) ◽  
pp. 470-472
Author(s):  
H. Lecoanet ◽  
J. Piranda
Keyword(s):  
Experimental Data ◽  
Eigenvalue Problem ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Rings ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with the problem of eigenfrequencies and eigenvectors for rings whose cross section may be decomposed in basic rectangular cross sections. The solution is derived from a solution of the in-plane eigenvalue problem for rectangular cross-section thick rings. A good agreement between theoretical results and experimental data is obtained.

Production of 67Cu by enriched 70Zn targets: first measurements of formation cross sections of 67Cu, 64Cu, 67Ga, 66Ga, 69mZn and 65Zn in interactions of 70Zn with protons above 45 MeV

2020 ◽  
Vol 108 (8) ◽  
pp. 593-602 ◽  
Author(s):  
Gaia Pupillo ◽  
Liliana Mou ◽  
Petra Martini ◽  
Micòl Pasquali ◽  
Alessandra Boschi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cancer Therapy ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
High Intensity ◽  
Chemical Processing ◽  
Γ Spectrometry ◽  
First Time ◽  
Theoretical Results

AbstractDespite its insufficient availability, Copper-67 is currently attracting much attention for its enormous potential for cancer therapy as theranostic radionuclide. This work aims to accurately measure the unexplored cross section 70Zn(p,x)67Cu in the energy range 45–70 MeV and to evaluate its potential advantages in the case of high-intensity proton beams provided by compact cyclotrons. Thin target foils of enriched 70Zn were manufactured by lamination at the INFN-LNL and irradiated at the ARRONAX facility using the stacked-foils method. A radiochemical procedure for the separation of Cu, Ga and Zn contaminants and the isolation of 67Cu from the irradiated material was developed. The efficiency of the chemical processing was determined for each foil by monitoring the activity of selected tracer radionuclides (61Cu, 66Ga and 69mZn) through γ-spectrometry. Experimental data of the 70Zn(p,x)67Cu, 64Cu, 67Ga, 66Ga, 69mZn, 65Zn cross sections were measured for the first time in the energy range 45–70 MeV and compared with the theoretical results obtained by using the TALYS code. The 67Cu production yield by using enriched 70Zn thick targets was compared with the results obtained by using 68Zn targets in the same irradiation conditions.

Modal Curves of Pre-Twisted Beams of Rectangular Cross-Section

1969 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
B. Dawson ◽  
W. Carnegie
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Twist Angle ◽  
Ritz Method ◽  
Transformation Method ◽  
Mode Shapes ◽  
Modes Of Vibration ◽  
Vibrational Characteristics ◽  
Theoretical Results ◽  
Good Agreement

An important aspect of the theoretical study of the vibrational characteristics of turbine and compressor blading is the prediction of the modal curves from which the stresses along the length of the blading can be determined. The accurate prediction of the modal curves allowing for such factors as pre-twist, camber, size of cross-section, centrifugal tensile effects, aerodynamic effects, etc., is still not possible. However, a better understanding of the effects of some of these parameters can be obtained by a study of the modal curves of relatively simple idealized models. In this work the theoretical mode shapes of vibration of pre-twisted rectangular cross-section beams for various width to depth ratios and pre-twist angle in the range 0-90° are examined. The theoretical results are obtained by the transformation method given by Carnegie, Dawson and Thomas (1)† and the accuracy of these results is verified by comparison with results obtained by Dawson (2) using the Ritz method. The theoretical results are compared to modal curves determined experimentally and good agreement is shown between them. A physical explanation of the effects of the pre-twist angle upon the modal curves is given for the first three modes of vibration.

scholarly journals Elastic scattering of low-energy electrons by OCS molecules.

2000 ◽  
Vol 53 (3) ◽  
pp. 399 ◽  
Author(s):  
M. H. F. Bettega ◽  
M. A. P. Lima ◽  
L. G. Ferreira
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Electron Scattering ◽  
Cross Sections ◽  
Ab Initio Calculation ◽  
Low Energy ◽  
Low Energy Electrons ◽  
Exchange Approximation ◽  
Low Energy Electron ◽  
Theoretical Results

We report results from an ab initio calculation of low-energy electron scattering by OCS molecules. We used the Schwinger multichannel method with pseudopotentials at the fixed-nuclei static-exchange approximation to calculate elastic integral, differential and momentum transfer cross sections in the energy range from 5 to 50 eV. We compare our results with available theoretical results and experimental data. Through the symmetry decomposition of our integral cross section and eigenphase sum analysis, we found structures in the cross sections that may be interpreted as shape resonances for ∑, ∏ and Δ symmetries. We compared the results for OCS with our previous results on the e––CS2 collision. In particular, we found a similar behaviour in the shape of the symmetry decomposed cross sections of OCS and of CS2 when, for the latter, we sum over the ‘g’ and ‘u’ contributions.

THE (n, p) CROSS SECTIONS OF TITANIUM ISOTOPES FOR NEUTRON ENERGIES BETWEEN 13.6 MeV AND 19.5 MeV

1966 ◽  
Vol 44 (10) ◽  
pp. 2337-2352 ◽  
Author(s):  
H. L. Pai
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Cross Sections ◽  
Emission Cross Section ◽  
Closed Shell ◽  
Proton Emission ◽  
Neutron Energy Range ◽  
Nuclear Temperature ◽  
Good Agreement ◽  
Titanium Isotopes

Using enriched titanium samples, the activation (n, p) and (n, pn; n, np; n,d) cross sections have been measured for the five isotopes of titanium in the neutron energy range from 13.6 to 19.5 MeV. The results were compared with calculations based primarily upon Bodansky's theory (1962), where the first proton emission cross section was taken to be the sum of (n, p) and (n, pn). The (n, pn) cross section was separated from the experimental (n, pn; n, np; n, d) cross section by a multiple-emission calculation. Using the nuclear temperature derived from the experimental data, good agreement was achieved between experiment and theory. It was found that the parameters of Bodansky's equation for the titanium isotopes could be adopted directly from the mass parabolas (Dewdney 1963). It was also found that the (n, p) cross sections were not influenced appreciably by the neutron closed shell.

Flow in the Hydrodynamic Entrance Region of Ducts of Arbitrary Cross Section

1969 ◽  
Vol 91 (3) ◽  
pp. 345-354 ◽  
Author(s):  
David P. Fleming ◽  
E. M. Sparrow
Keyword(s):  
Experimental Data ◽  
Velocity Field ◽  
Pressure Drop ◽  
Cross Section ◽  
Cross Sections ◽  
Solution Method ◽  
Arbitrary Cross Section ◽  
Entrance Region ◽  
General Method ◽  
Good Agreement

A general method of analysis is presented for determining the developing velocity field and pressure drop for laminar flow in the entrance region of ducts having arbitrary cross sections. Application of the solution method is made to rectangular ducts and to triangular ducts. Available experimental data are compared with the analytical results and good agreement is found to prevail. Development characteristics for six ducts are brought together and compared, and various trends are identified.

Analysis of fusion cross-sections of 6He, 8He and 11Li halo nuclei by using temperature-independent and temperature-dependent potentials

2019 ◽  
Vol 35 (04) ◽  
pp. 2050005
Author(s):  
M. Aygun
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Halo Nuclei ◽  
Fusion Reactions ◽  
Temperature Dependent ◽  
Dependent Potential ◽  
Theoretical Results ◽  
Good Agreement

Analysis of the fusion reactions of halo nuclei is one of the important subjects of nuclear physics. In addition, temperature-dependent analysis of fusion cross-sections of these nuclei is a deficient topic in the literature. In order to overcome this deficiency, the fusion cross-sections of 6He, 8He and [Formula: see text]Li which are the most important halo nuclei are analyzed by using both temperature-independent potential and temperature-dependent potential. All the theoretical results are compared with each other as well as the experimental data. It is seen that the results of temperature-independent potential are in good agreement with the data while the temperature-dependent potential has a significant impact on the fusion cross-sections. Finally, the changes with the temperature of both real and nuclear potentials of all the reactions are investigated.

Explanation of the Influence of Inflow Air Content on the Lift of Cavitating Hydrofoils

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Lift Coefficient ◽  
Cavity Surface ◽  
Air Bubbles ◽  
Incoming Flow ◽  
Fluid Density ◽  
Air Content ◽  
Theoretical Results ◽  
Good Agreement

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.

Stresses and Displacements on the Boundaries of Circular Rings Diametrically Loaded

1986 ◽  
Vol 53 (1) ◽  
pp. 213-219 ◽  
Author(s):  
A. J. Durelli ◽  
Y. H. Lin
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Boundary Values ◽  
Structural Applications ◽  
Circular Rings

The paper deals with stresses and displacements in circular rings of rectangular cross-section, loaded in the plane and perpendicular to the boundary. Values are given for all points at the inside and outside boundaries, are presented parametrically for rings for which the ratio of diameters ID/OD varies from 0 to very close to 1, and have been obtained from several sources, mainly Nelson’s equations. References to some previous contributions are included. The information presented in the paper was not available in a complete manner and will be useful in numerous structural applications. The analysis corresponding to loads applied tangentially to the boundary could be approached in a similar manner.

scholarly journals Particle separation of a modified feed nozzle hydrocyclone under different operating parameters

2021 ◽  
Vol 11 (5) ◽  
pp. 159-170
Author(s):  
Zsolt Hegyes ◽  
Máté Petrik ◽  
L. Gábor Szepesi
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Cross Section ◽  
Particle Separation ◽  
Baffle Plate ◽  
Important Data ◽  
Preliminary Research ◽  
All Speeds ◽  
Plate Solution

During the operation of the hydrocyclone the cut size diameter is the most important data. This is connected to feed rate, which is closely related to the feed cross section. Preliminary research has revealed that square cross-section is more effective than circular cross-section. The research compared 2 types of feed cross sections at 5 different feed rates. One is a standard rectangular cross-section and the other is a square cross-section that narrows with a baffle plate. Preliminary calculations for cut size diameter have shown that better particle separation at all speeds can be achieved with the baffle plate solution. In both types, the increased velocity created decreased cut size diameter. During the simulation, the baffle plate did not cause any abnormalities in the internal pressure and velocity distributions. The simulation revealed that the particles did not behave as previously calculated.

scholarly journals Energy Dependence of Total Cross Sections for Reactions with 4, 6he, 6, 7, 9li Nuclei

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Yu Penionzhkevich ◽  
Yu Sobolev ◽  
V Samarin ◽  
M Naumenko
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Numerical Solution ◽  
Energy Dependence ◽  
Cross Sections ◽  
Beam Energy ◽  
Microscopic Analysis ◽  
Time Dependent ◽  
Total Cross Sections ◽  
Good Agreement

The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data.

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