Investigations into the standardization and reproducibility of the urinary excretion method for determining the absorption of tritiated folic acid were carried out. By proper timing of tissue-loading doses of folic acid a clear difference between the percentage excretion ranges of normal and coeliac subjects was obtained. In addition conditions were found whereby the procedure could be repeated...

Accurate measurements of interstellar deuterium abundances along lines of sight extending out to several hundred parsecs by FUSE and other instruments is making D/H a useful tool for understanding Galactic chemical evolution. We find that the gas inside of the Local Bubble is chemically homogeneous, but that large variations in D/H beyond the Local Bubble are real and challenge present concepts...

Biochemical analyses of substances rely upon the ability of techniques to identify qualitatively and quantitatively the components present and are based on physicochemical characteristics as well as chemical nature of substances being detected. While chemical analyses usually depend on reactions of a given substance and can be destructive, spectral studies are usually non-destructive and deal w...

Reactive absorption — i.e., the absorption of gases in liquid solutions accompanied by chemical reactions — is an important industrial operation for the production of basic chemicals (e.g., sulfuric or nitric acid) and for the removal of harmful substances (e.g., H2S) from gas streams. In recent decades, this process has become especially important for the purification of gases to high purities...

The atomic structure and the chemical composition of buried interfaces is of high interest for many applications e.g. in multilayered samples such as oxidized metals, optic or microelectronic devices. Conventional surface analytical techniques such as X-ray photoelectron spectroscopy (XPS), Auger-electron spectroscopy (AES) or ion scattering spectroscopy (ISS) have an extremely high surface sen...

zno plays an important role in many semiconductors technological aspects.  here,  direct  precipitation  method  was  employed  for  the synthesis of nano-sized hexagonal zno particles, which is based on chemical  reactions between  raw materials used  in  the  experiment. zno  nanoparticles  were  synthesized  by  calcinations  of  the  zno precursor precipitates  at 250  ˚c  for 3hours. the p...

The local structure and chemical bonding in two-phase amorphous Cr1−xCx nanocomposite thin films are investigated by Cr K-edge (1s) X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies in comparison to theory. By utilizing the computationally efficient stochastic quenching (SQ) technique, we reveal the complexity of different Cr-sites ...