by means of first principles calculations we show that both rutile and anatase phases of bulk tio2 doped by s, se or pb can display substantial decreasing in the band gap (up to 50%), while doping by zr does not sizably affect the band-gap value. moreover, the absorption edge is shifted (up to 1 ev) to the lower energy range in the case of tio2 doped by s or pb that opens a way to enhancing of ...

background: sound is one of the most important factors threatening workers’ health. the most efficient and practical method for controlling noise pollution is the use of sound-absorbing materials. impedance tube with two microphones is used to determine the sound absorption coefficients and should be tested periodically for accuracy and efficiency. the purpose of present study was assessing the...

The applicability of algorithms for estimation of phycocyanin (PC) concentration based on light spectral reflectance heavily depends on the specific absorption of the pigment. But the determination of PC-specific absorption coefficient is not a straightforward task, as PC optical activity is overlapped by absorption of chlorophylls. The aim of our study was to determine a PC(625)—the specific a...

Professor R. A. Millikan' has recently found evidence for the existence of very penetrating radiation which originates from sources outside of the earth. The mass-absorption coefficient of these rays is but 0.0018 per gram of water, which is far below the absorption coefficient of the hardest gamma rays. These Millikan rays are so short that their total mass-absorption coefficient isequal to th...

objectives in this study, the absorption coefficient of hemoglobin (hb) was used to distinguish between normal and abnormal breast tissue. materials and methods a near-infrared source (637 nm) was transmitted from major and minor vessels of a breast phantom containing 2×, 4× concentrations of oxy- and deoxy-hb. the absorption coefficients were determined from spectrometer (sm) and powermeter (p...