Optimization of preparation parameters and characterization of the Mn0.5Zn0.5Fe2O4 thermal-sensitive magnetic ferrofluid prepared by the hydro-thermal method
The bare magnetic Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> nanoparticles were prepared by the hydro-thermal method. The optimized preparation conditions were obtained by the orthogonal experiment. Crystal structure and the grain diameter of the particles were observed by X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM), and the Curie temperature of the bare particles and the performance of the magnetic moment of the particles at different temperatures were characterized by the Vibrating Sample Magnetometer (VSM). The bare particles were modified by the oleic acid, and the modification effect was verified by the Infrared Test (IR). Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> thermal-sensitive magnetic ferrofluid with excellent performance were prepared by dissolving the modified particles in the kerosene carrier. The saturation magnetization could reach up to 278Gs and the Curie temperature is confirmed to be 322K, which indicates that the quality of the Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> thermal-sensitive ferrofluid is better than other Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> thermal-sensitive ferrofluids prepared by the coprecipitation method previously reported (Saturation magnetization: 150Gs, Curie temperature: 340K[1]).
Hydrothermal preparation of ultrafine ferrites and their sintering
Preparation de poudres ultrafines et quasispheriques de ferrites NiFe 2 O 4 , ZnFe 2 O 4 , Ni x Zn 1−x Fe 2 O 4 , Mn 0,5 Zn 0,5 Fe 2 O 4 et CoFe 2 O 4 dans des conditions hydrothermales moderees par precipitation de nitrates metalliques avec de l'ammoniaque. Ces poudres sont frittees a 1000°C sans additif avec obtention d'une densite proche de la densite theorique
Within and Inter-Institutional Differences Between Death Certifiers on Autopsy Conclusions
This study seeks to establish whether medico-legal practitioners differ in their autopsy conclusions within and across medico-legal institutions. Data include 459 violent deaths (homicides, suicides, and accidents) autopsy reports written by more than 20 death certifiers from four medico-legal institutions in two countries (France and the United States). Multinomial models show that compared with accidental deaths, weapon use and decedents’ characteristics both influence a homicide verdict, but not a suicide one. In addition, French practitioners are more likely than Americans to reach a conclusion of homicide or suicide compared with accident, and homicides are more likely to be certified by male practitioners.