Magnetite, maghemite, and hematite have been the subject of numerous studies using vibration spectroscopy to determine their infrared- and Raman-active phonons. However, no complete and unambiguous set of experimentally observed optically active phonons has yet been reported for these iron oxides. The use of atomistic simulation methods with a transferable Buckingham potential provides new data for the phonon densities of states of magnetite and the two associated phases, hematite and maghemite.

Microbiologically influenced corrosion (MIC) of stainless steel (SS) can be caused by the action of metal-oxidizing bacteria (MOB) in natural, relatively low-chloride waters. This type of corrosion is frequently associated with ennoblement of the open-circuit potential and involves iron-oxidizing bacteria (IOB) and manganese-oxidizing bacteria (MnOB). This work focuses of the role of IOB and associated inorganic water chemistry processes that may cause corrosion of SS. Laboratory and field studies have been conducted to investigate the influence of deposited ferric oxide (or oxyhydroxide) on the corrosion of UNS S30403. Samples exposed to a natural spring water reached open-circuit potentials of 250 mV vs saturated calomel electrode (SCE) and were covered by a biofilm containing a mixture of geothite (α-FeOOH), lepidocrocite (γ-FeOOH), and magnetite (Fe 3 O 4 ) or maghemite (γ-Fe 2 O 3 ), together with low levels of manganese-based deposits. In the laboratory, an iron-based film was formed on some samples by oxidation of ferrous sulfate (FeSO4 ) with calcium hypochlorite (Ca[ClO] 2 ), giving a surface film with a composition similar to that produced by microbial activity. These samples did not show ennoblement, but they did show lower pitting potentials than were measured for control samples. The results of this work are consistent with the idea that MIC of SS in potable water involves manganesebased deposits causing ennoblement (W.H. Dickinson, F. Caccavo Jr.

In the field of proteomics the quantification of the affinity of an antibody to its partners and the evaluation of its specific binding is an important issue. With an imaging ellipsometer the interaction of an antibody with immobilized antigens on a model microarray is observed in a time-resolved and label-free manner. Imaging ellipsometry was developed for real-time monitoring of the biomolecule interaction between an antigen in solution and an antibody immobilized on a silicon surface. Proteins were immobilized by the formation of carboxy-alkyl monolayers on silicon substrates, where a biotin-labelled antibody was immobilized by a biotin–streptavidin linkage. Anti-human IgG bound specifically to human antibody and protein A, similarly anti-goat IgG bound to goat antibody. No binding was observed between anti-rabbit IgG and goat antibody. All stages of the formation of the antigen–antibody complex were imaged by imaging ellipsometry. By monitoring changes in y, the mole fraction θ of the antigen–antibody binding was determined. Immunological reactions of two different antigen–antibody combinations were fitted by the Langmuir adsorption equation, and affinity constants for two reactions were calculated.