scholarly journals The Gaussian cannon

2017 ◽  
Vol 1 ◽  
pp. 6 ◽  
Author(s):  
Åke Andersson ◽  
Carl-Joar Karlsson ◽  
Hampus Lane
Keyword(s):  
Potential Energy ◽  
Optimal Number ◽  
Attractive Force ◽  
Firing Process ◽  
Ejection Speed ◽  
Steel Balls

This report studies different properties of a Gaussian cannon. The cannon’s firing velocity is measured for a varying number of steel balls, varying input velocity and different geometries of the cannon. By measuring the attractive force from the magnet on the balls a mapping of the potential energy for the firing process is acquired. It is found that the firing of a Gaussian cannon can be modeled as successive collisions between the magnet and its neighboring balls, and between successive balls. To reach the highest possible ejection speed with a trigger ball that is released from rest, a chained cannon should be used. The optimal number of balls on each individual cannon depends on magnetization energies and coefficients of restitution.

scholarly journals Material Factors in Relation to Development Time in Liquid-Penetrant Inspection. Part 1. Material Factors

2016 ◽  
Vol 61 (2) ◽  
pp. 509-514 ◽  
Author(s):  
P. Irek ◽  
J. Słania
Keyword(s):  
Potential Energy ◽  
Development Time ◽  
The Other ◽  
Attractive Force ◽  
Material Surface ◽  
Penetration Testing ◽  
Factors Affecting ◽  
Material Type ◽  
Adhesion Joint ◽  
European Standards

Abstract In technical publications and European Standards the development time (i.e. time of getting out of penetrant from a discontinuity to the material surface) in penetration testing is specified within the range of 10-30 minutes. In practice, however, it is seen , that it is closely connected with the material type and ranges from several minutes to 24 hours. In the literature, only interactions coming from the penetrant are described, whereas those from the material under testing, i.e. the influence of material factors on adhesion between penetrant and material, are not taken into consideration. In this connection, it has been described precisely in the paper the adhesion phenomenon and also it has been indicated the other factors affecting the development time. Recapitulating the adhesion theories presented in the paper, it can be formulated two fundamental circumstances which must occur that adhesion joint may be formed, namely: the approach of the particles of two solids to the distance less than 0,9 nm while the high attractive force occurring between molecules should be connected with possibly low potential energy of the bond formed in this way.

scholarly journals Operationally Complete Work Done Suggests Presence of Extra Potentials Corresponding to Repulsive Forces

2014 ◽  
Vol 37 ◽  
pp. 16-30
Author(s):  
Jakub Czajko
Keyword(s):  
Potential Energy ◽  
Force Field ◽  
Gravitational Force ◽  
Force Fields ◽  
Attractive Force ◽  
Mass Source ◽  
Complete Representation ◽  
Complete Work ◽  
Repulsive Forces ◽  
Work Done

Operationally complete representation of work done and the corresponding to it potential energy within the usual radial/center-bound, nonrotating gravitational force fields comprises two extra terms: linear nonradial and angular nonradial, in addition to the usual radial term. Since these nonradial terms have negative signs, they suggest presence of potentials corresponding to repulsive forces generated by the very same, usual radial attractive force field. The extra linear nonradial term depends on exposure of an orbiting satellite to the distribution of mass within the field, whereas the extra angular nonradial term also depends on that as well as on exposure of the satellite to density of matter of the mass source that generates the usual, locally dominant radial/center-bound attractive gravitational force field.

Optimal Experimental Design With Nesting of Persons in Organizations

2013 ◽  
Vol 221 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Gerard J. P. van Breukelen
Keyword(s):  
Repeated Measures ◽  
Optimal Number ◽  
Health Centers ◽  
Randomized Experiments ◽  
Optimal Sample ◽  
Treatment Conditions ◽  
Sampling Cost ◽  
Nested Designs ◽  
Simple Equations ◽  
Number Of Individuals

This paper introduces optimal design of randomized experiments where individuals are nested within organizations, such as schools, health centers, or companies. The focus is on nested designs with two levels (organization, individual) and two treatment conditions (treated, control), with treatment assignment to organizations, or to individuals within organizations. For each type of assignment, a multilevel model is first presented for the analysis of a quantitative dependent variable or outcome. Simple equations are then given for the optimal sample size per level (number of organizations, number of individuals) as a function of the sampling cost and outcome variance at each level, with realistic examples. Next, it is explained how the equations can be applied if the dependent variable is dichotomous, or if there are covariates in the model, or if the effects of two treatment factors are studied in a factorial nested design, or if the dependent variable is repeatedly measured. Designs with three levels of nesting and the optimal number of repeated measures are briefly discussed, and the paper ends with a short discussion of robust design.

CO2 and CO monolayers on MgO(100) : LEED experiments and potential energy calculations

1994 ◽  
Vol 4 (6) ◽  
pp. 905-920 ◽  
Author(s):  
V. Panella ◽  
J. Suzanne ◽  
P. N. M. Hoang ◽  
C. Girardet
Keyword(s):  
Potential Energy ◽  
Energy Calculations ◽  
Potential Energy Calculations
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