(HVL) is better than ordinary concr

(HVL) is better than ordinary concrete and commercial window.
The cutoff wavelengths from optical absorption spectra of Bi2O3,
PbO and BaO glasses were found to be 510, 420 and 370 nm,
respectively. All glasses were transparently yellow with its intensity
increasing as a function of additives content. The Bi2O3 and
BaO glasses will open new possibility for a lead-free radiation protecting
glass with non-toxicity to our environment.