scholarly journals A Semi-empirical Law for Sputtering in Plasma Devices

1982 ◽  
Vol 35 (6) ◽  
pp. 699
Author(s):  
JL Cook ◽  
EK Rose ◽  
JW Connolly

A general law is given for sputtering coefficients as a function of the energy of hydrogen and helium isotope ions incident on metallic and graphite walls and limiters. The average over a Maxwellian spectrum is performed analytically.

2011 ◽  
Vol 1 (5) ◽  
pp. 33
Author(s):  
R. R. Minikin

"Every ultimate fact is but the first of a new series and every general law only a particular fact of some more general law presently to disclose itself. Ralph Waldo Emerson was not a scientist but he wrote many wise things about human ways and notions. The words of this quotation condense with brevity the whole history of the studies relative to that branch of oceanography devoted to sea behaviour about our shores. Within the last half century there has been a great deal of research on the subject although with different ends in view; some were concerned with marine life and fisheries, some with variation of gravity, others with hydrography and others with the movement of the mobile material on the sea bed, currents and tides. Another type of research of no less importance was the delving into relevant historical records of centuries past of Dutch, French and Italian sea-going map makers. In this connection it was a well known Italian engineer who brought to light the works of a great English chart maker of the Mediterranean, Admiral Henry Smyth (1810) who for twenty years sailed that sea. It is only within recent years that there has been a dissemination of the data collated by these specialist compartmental researches through such Associations as this and it is all to the good of man. The difficulties of hydrodynamic studies are too well-known to require emphasis here excepting to underline the fact that most of the popular quantitative formulae are of a semi-empirical nature. It is therefore easy to appreciate the divergences of opinions of what is essential to a clear understanding and evaluation of the factors that must weigh in the diagnosis of beach behaviour subjected to the complex sea action. It is the purpose of this paper to examine briefly those things recorded from authoritative observations of the phenomena and the reasons and the remedies more usually proposed, or executed for the given conditions in various countries. The author has already suggested elsewhere that the personal approach to these problems should be definitely linked to a sea-sense, in other words a keen interest in and contact with the sea in all its moods.


2006 ◽  
Vol 15 (4) ◽  
pp. 447 ◽  
Author(s):  
Imma Oliveras ◽  
Josep Piñol ◽  
Domingos X. Viegas

The concept of fire line rotation was applied to curved fire line elements like those of a point ignition fire in a slope or in a wind field. Convective effects induced by the fire modify the shape of the flame around its perimeter and affect the propagation of the fire front. From the analysis of laboratory experiments under wind or slope conditions, the existence of a rotation movement of the fire line elements is demonstrated. It is also shown that the semi-empirical law developed for straight lines is applicable with some adjustments to curved fire lines.


2020 ◽  
Vol 61 (5) ◽  
pp. 77-87
Author(s):  
Thang Trong Dam ◽  
Lam Tung Vu ◽  

When it comes to blasting in soil, in general, and blasting in clay medium under water, in particular, typical parameters for destruction effect of explosion known as splashed funnel based on water depth, the depth of buried explosives in clay medium and the explosive mass. This relation is multidimensional and multivariable. Using traditional integation addressing empirical data still has limits in presenting a general law in entire domain relating to such relation. Therefore, based on the empirical results collected from the previuos study, this paper will concentrate to make a machine learning algorithm building a regression model, finding the general empirical law about the dependence relation of the radius of splashed funnel in clay medium under water, based on splashed funnel and the water depth, the depth of buried explosives in clay medium and the radius of explosives charges. The efficiency of the model will be evaluated with correlation coefficent R2 between the calculated values of funnels and its real values in experiments. Consequently, the model reached high accuracies which can be applicable in the reality.


2021 ◽  
Vol 120 ◽  
pp. 114096
Author(s):  
M. van Soestbergen ◽  
Q. Jiang ◽  
J.J.M. Zaal ◽  
R. Roucou ◽  
A. Dasgupta

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