A UHV atomic hydrogen-cracking cell has been constructed to produce atomic hydrogen in order to perform in-situ cleaning of semiconductor samples. The cell was calibrated and tested with the objective of cleaning the III-V semiconductor samples such as GaAs. Mass spectroscopy studies during the atomic hydrogen cleaning of the GaAs samples revealed the chemical process of the hydrogen cleaning. ...

Plants of the genus Euphorbia have been investigated for different bioactive natural products. I have isolated several new and bioactive diterpenoids from different species of Euphorbia of Iran with myrsinane type skeleton. The structure of the compounds was determined using high resolution mass spectroscopy, 1 D and 2 D NMR spectral data. The stereochemistry of the diterpenoids was determined ...

the composition of the essential oils of two african (“white” and “yellow”) olibanums available in the commercial market of isfahan (iran) was analyzed by gas chromatography (gc) and gc-mass spectroscopy methods. the main constituents of the “white” olibanum oil were alpha-pinene (34.8%), limonene (15.9%), alphathujene (9.0%), para-cymene (7.0%), myrcene (6.2%) and sabinene (6.0%). major compon...

The analysis of human breath has been driven to new heights and has great potential to impact our society in the area of medical science. Breath analysis is promising as non-invasive, simple and point-of-care clinical measurements to reduce the medical burden caused by invasive, time-consuming and expensive clinical devices. Spectroscopic techniques for breath analysis can offer information to ...

Preclinical brain receptor occupancy measures have heretofore been conducted by quantifying the brain distribution of a radiolabeled tracer ligand using either scintillation spectroscopy or tomographic imaging. For smaller animals like rodents, the majority of studies employ tissue dissection and scintillation spectroscopy. These measurements can also be accomplished using liquid chromatography...

Plants of the genus Euphorbia have been investigated for different bioactive natural products. I have isolated several new and bioactive diterpenoids from different species of Euphorbia of Iran with myrsinane type skeleton. The structure of the compounds was determined using high resolution mass spectroscopy, 1 D and 2 D NMR spectral data. The stereochemistry of the diterpenoids was determined ...

In this study, we report the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) for the identification and quantitation of two polymorphs of Aprepitant, a substance P antagonist for chemotherapy-induced emesis. Mixtures of the polymorph pair were prepared by weight and ATR-FT-IR spectra of the powdered samples were obtained over the wavelength range of 700-1...