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Date: 30-3-2019
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Date: 14-12-2018
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Date: 12-1-2018
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Tritium
Tritium occurs in the upper atmosphere and is formed naturally by reaction 1.1, involving neutrons arriving from outer space. Tritium (see Section 2.8) was first obtained synthetically by the bombardment of deuterium compounds such as [ND4]2SO4 with fast neutrons, but is now prepared from lithium deuteride, LiF or Mg/Li enriched in 63 Li (equation 1.2).
(1.1)
(1.2)
Tritium is radioactive, a weak b-emitter with t1/2= 12.3 yr. It is used extensively as a tracer, in both chemical and biochemical studies; its weak radioactivity, rapid excretion and failure to concentrate in vulnerable organs make it one of the least toxic radioisotopes.
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مخاطر خفية لمكون شائع في مشروبات الطاقة والمكملات الغذائية
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"آبل" تشغّل نظامها الجديد للذكاء الاصطناعي على أجهزتها
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تستخدم لأول مرة... مستشفى الإمام زين العابدين (ع) التابع للعتبة الحسينية يعتمد تقنيات حديثة في تثبيت الكسور المعقدة
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