The structure of ultrathin Langmuir-Blodgett films of cadmium behenate.
Grazing incidence x-ray-diffraction investigations of the structures of Langmuir-Blodgett films of cadmium behenate with 1, 2, 3, 5, and 21 monolayers are reported. The single monolayer film, deposited on a hydrophilic substrate, showed a hexagonal structure, whereas the bilayer film, deposited on a hydrophobic substrate, had a rectangular structure with herringbone orientation of the acyl chains. With multilayer films formed on a hydrophilic substrate, it was possible to detect that the hexagonal structure of the first layer was retained when additional layers were deposited and that the additional layers had the same rectangular structure as the bilayer.
Structures of head-group and tail-group monolayers in a Langmuir-Blodgett film.
We have studied monolayer and multilayer Langmuir-Blodgett films of lead stearate using x-ray diffraction and reflectivity. We show that it is possible to distinguish the scattering due to the head groups from that due to the alkane chains. The second and subsequent alkane monolayers are distorted hexagonal (the first monolayer is known to be hexagonal); successive monolayers are shifted laterally by one-fourth of an in-plane lattice spacing, and the chains tilt by {similar_to}8{degree} towards a nearest neighbor. The lead ion monolayers are also distorted hexagonal; successive monolayers are shifted laterally by a half lattice spacing. From rod scan intensities, we have determined the relative positions of the lead and alkane chain lattices.
As práticas profissionais no campo público de atenção à saúde bucal: o caso de dois municípios da Bahia
This paper examines the working facilities and processes of dentists in the primary healthcare systems of two towns in Bahia State, Brazil, striving to analyze the extent to which factors related to dental care, training, placement and professional profiles influence their practices. Semi-structured interviews were conducted with nine dentists in both towns, with work process organization patterns in Municipality C being closer to the structuring principles of Brazil's National Health System than in Municipality E. This seems to be related to management characteristics, with networking links among individual, collective, and preventive clinical activities and planning noted in Municipality C. Despite these differences, the practitioners presented similarities in terms of dual militancy and perceptions of the public and private healthcare fields. The hegemony of the private sector seems to be influencing the professional practices of dentists in the public health system.