Kerma

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kerma

[′kər·mə]
(nucleonics)
The kinetic energy imparted to charged particles in a unit mass of material by uncharged particles such as neutrons; it may be expressed as joules per kilogram or ergs per gram.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Kerma

 

(ancient Egyptian, Inbu Amenemhet—“Walls of Amenemhet”), a Cushitic settlement south of the third cataract of the Nile, on its right bank (Sudan). Excavations conducted from 1913 to 1916 have revealed a settlement dating from the time of Egypt’s Middle Kingdom (20th-18th centuries B.C.), a necropolis of local rulers buried with their relatives and slaves (as many as 400 persons in one burial); and numerous remains of material culture and art, both of local and Egyptian origin. Kerma lost its importance after Cush was conquered by Egypt (by the 15th century B.C.).

REFERENCES

Katsnel’son, I. S. “Problemy istoricheskogo razvitiia drevneishei Nubii.” Vestnik drevnei istorii, 1948, no. 2.
Reisner, G. A. Excavations at Kerma, vols. 1–2. Cambridge, 1923.
Hintze, F. “Das Kerma-Problem.” Zeitschrift für ägyptische Sprache und Altertumskunde, 1964, vol. 91.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
A Kruskal-Wallis H test was conducted to detect a statistically significant difference between phase and each of DAP, air kerma, and acquisition time.
On the left is the Radcal IC used to measure incident air kerma from x-ray backscatter systems that were installed at NIST for extended study.
Both FACs are proven national-standard instruments deemed suitable for the realization of air kerma for these sources.
(7) The final result is a linear but inverse relationship between the S-value and the average air kerma or exposure of the region of interest.
Key words: air kerma; free-air ionization chamber; gamma-ray, cesium 137; primary-standard; reference radiation qualities; x-ray calibration.
The PTB x-ray air kerma measurements were made using the PK100 primary standard free-air ionization chamber.
Key words: air kerma; brachytherapy seeds source; exposure; free-air chamber; [.sup.125]I; national measurement standard; [.sup.103]Pd; x rays.
Key words: air kerma; cavity chamber; electron stopping-power ratio; exposure; humidity correction; Monte Carlo; national standard; photon energy-absorption coefficient ratio; radiative-loss correction; wall correction.
Relative standard uncertainties (in %) associated with the calibration of the transfer ionization chambers NIST BIPM Source of Type A Type B Type A Type B uncertainty Air kerma rate 0.05 0.36 0.05 0.21 Ionization current 0.02 0.13 0.04 0.02 Positioning 0.01 0.01 0.01 [N.sub.K,LAB] 0.05 0.38 0.07 0.21 Table 8.
The data shown are converted from dose in mrad to air kerma rate in nGy/h, without correction factors (4) applied.
This Unit is not in general use, and the quantity exposure will probably be replaced by the quantity air kerma. which has the unit gray (Gy).