[en] A generalized equation relating equilibrium data, phase ratio and fractional recovery is developed. The use of this equation reduces the presentation of these data to a single dimensionless curve independent of the system and the operating conditions. The validity of this equation is tested using experimental data for different liquid - liquid systems at various condition. a reasonable agreement between experimental results and predicated ones was obtained. The use of this equation in investigating the effect of phase ratio on the fractional recovery is illustrated. (authors). 6 refs., 4 figs., 3 tabs

[en] Different kinds of thin-film coatings were investigated with regard to their applicability as hydrophobic coatings for MEMS. The films were deposited onto silicon and borosilicate glass substrates by spincoating of Dyneon(TM) PTFE and PFA, plasmapolymerization of HMDS-N and C₄F₈ as well as liquid-phase and vapor-phase coating of SAMs from DDMS, FDTS, FOTS and Geleste Aquaphobe(TM) CM. The layer properties were analyzed using profilometry, FTIR, SEM and contact angle measurements. Furthermore, the adhesion of the layers to the substrates was determined in an acetone ultrasonic bath. The influence of various deposition process parameters on the properties of the films was investigated. As these layers can be used in microfluidic systems, as water-repellent layers and as anti-stiction coatings, they are suited for versatile fields of application

[en] Fifty nine 6 week-old Sprague Dawley male rats were inoculated near the left angle of the mandibular bone with radioactive colloidal cerium. Fifty three rats presented orofacial tumours: forty-two single tumours and 11 double tumours. The survival time of animals with tumours ranged between 262 to 501 days after inoculation of cerium. Six rats died without tumours. Squamous cell carcinomas (SCC) and bone and soft tissue (BSTS) sarcomas were the predominant histological types (respectively 42 SCC and 14 (BSTS). Other types of tumours were also observed: 3 salivary adenocarcinomas, 3 tumours with double differrentiation, one ganglioneuroblastoma and one odontosarcoma. Double tumours were found in rats which had a significantly greater mean survival time, suggesting that the probability of double tumours increases with time. No correlation was found between the mean initial radioactivity and histological type of tumours, mean survival time, locoregional extension or presence of metastases. In general, the low incidence of metastases (17.3%) contrasted with a large locoregional extension. Only one out of five osteosarcomas of the mandible presented lung metastases, a low rate when compared to osteogenic osteosarcomas of the leg induced in rats by radioactive cerium (60-80% of metastases). The mean labelling index determined by autoradiographic study one hour after injection of 5.5 μ/g of tritiated thymidine was 23.7% +- 6.4% and 27.8% +- 6.8% respectively, for SCC and BSTS). These radio-induced tumours may constitute an interesting experimental model for human orofacial tumours

[en] The melting transition of a model semicrystalline polymer has been detected by the microcantilever deflection as a function of temperature. Deflection measurements were done on arrays of 8-cantilevers spin coated with the semicrystalline polymer: poly (propylene azelate). The melting of the polymer has been corroborated by grazing incidence wide angle x-ray scattering experiments performed with synchrotron radiation over a single cantilever.

[en] Highlights: ► The structural and optical properties of Cu_1−xCd_xFe₂O₄ thin films were studied. ► The micro structural parameters of the films have been determined. ► The room temperature reflectance and transmittance data are analyzed. ► The refractive index and energy gap are determined. ► The single oscillator parameters were calculated. - Abstract: Nanocrystalline thin films of mixed Cu–Cd ferrites, Cu_1−xCd_xFe₂O₄ (x = 0, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9 and 1), were deposited by electron beam evaporation technique. The films were annealed at 450 °C for 1 h. The effect of Cd doping on the structural and optical properties of the deposited films has been investigated by using X-ray diffraction (XRD) and optical spectrophotometry. XRD patterns of the annealed films show spinal cubic structure. The lattice parameter was found to increase with the increase of cadmium concentration. The crystallite size of the films was found to vary from 8 nm to 30 nm. The optical transition was found to be direct and indirect transitions with energy gaps decrease from 2.466 (x = 0) to 2.00 (x = 1) eV and from 2.148 (x = 0) to 1.824 (x = 1) eV, respectively. The refractive index dispersion of the films was found to increase with Cd content and discussed in terms of the Wemple–DiDomenico single oscillator model

[en] Highlights: ► The Mn doped ZnO nanocrystalline films were synthesized. ► The crystal structure of the films has been determined. ► Spectroscopic ellipsometry was analyzed to determine the optical constants. ► The magneto-transport properties of the films were studied. - Abstract: Nanocrystalline Zn_1−xMn_xO films (x = 0, 0.05, 0.1, 0.15, and 0.2) were deposited onto corning glass substrates by a non-vacuum sol–gel spin coating method. All of the films were annealed at 450 °C for 2 h. The structural, optical and magneto-transport properties were investigated by X-ray diffraction, spectroscopic ellipsometry and a system for the measurement of the physical properties. X-ray diffraction analysis of the films reveals that the Mn-doped ZnO films crystallize in the form of a hexagonal wurtzite-type structure with a crystallite size decreases with an increase of the Mn concentration. It was also found that the microstrain increases with the increase of the Mn content. Evidence of nanocrystalline nature of the films was observed from the investigation of surface morphology using transmission, scanning electron microscopy and atomic force microscopy. The optical constants and film thicknesses of nanocrystalline Zn_1−xMn_xO films were obtained by fitting the spectroscopic ellipsometric data (ψ and Δ) using a three-layer model system in the wavelength range from 300 to 1200 nm. The refractive index was observed to increase with increasing Mn concentration. This increase in the refractive index with increasing Mn content may be attributed to the increase in the polarizability due to the large ionic radius of Mn²⁺ compared to the ionic radius of Zn²⁺. The optical band gap of the nanocrystalline Mn–ZnO films was determined by an analysis of the absorption coefficient. The direct transition of the series of films was observed to have energies increasing linearly from 3.17 eV (x = 0) to 3.55 eV (x = 0.2). Magnetoresistance (MR) was measured from 5 K to 300 K in a magnetic field of up to 6 T. Low-field positive MR and high-field negative MR were detected in Mn-doped ZnO at 5 K. Only negative MR was observed for temperatures above 200 K. The positive MR in Mn-doped ZnO films was observed to decrease drastically when the temperature increased from 5 K to 100 K. The isothermal MR of Zn_1−xMn_xO films with different Mn concentrations at 5 K reveals that the increase of the Mn content induces a giant positive MR above x = 0.05 and reaches up to 55% at an applied field of 30 kOe for x = 0.2.

[en] The phase relations of the GdCo_13-xSi_x system have been studied by means of scanning microscopy, microprobe analysis and x-ray diffraction. Single-phase samples GdCo₉±_δSi₄±δ (structure type LaFe₉Si₄ with space group I4/mcm) are formed in a narrow composition range vertical bar δ vertical bar ≤0.2, where GdCo₉Si₄ forms as a fully ordered ternary compound. The magnetic properties of GdCo₉Si₄ have been investigated by ac susceptibility, magnetization, specific heat and resistivity measurements. These experiments reveal ferrimagnetism below about 47 K, which is analysed in terms of a two-sublattice molecular field model with a local moment Gd subsystem coupling antiparallel to the itinerant ferromagnetic Co 3d sublattice. The 3d-3d exchange of the latter is the driving force for the onset of long range magnetic order. The validity of the two-sublattice model is demonstrated by high field measurements, showing that the ferrimagnetic coupling starts to break up at a lower critical field μ₀H_l ∼ 27T. The magnetic ground state of GdCo₉Si₄ has been analysed on a microscopic basis via LSDA electronic structure calculations