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]).
Production and Application of Thermal Ferrite
Thermal ferrite at curie temperature 93 ℃ is made by suing ceramic process technology.Introduce teh production equipmetns and material.Analyse and discuss effective factors on material curie temperature and yield.Finally introduce principle and application of thermal magnetic switch.
Selected Ethical Issues in Research and Publication: Perceptions of Health Education Faculty
A national random sample of 195 university health education faculty at graduate degree–granting programs completed a 31-item survey with regard to their perceptions of ethical issues in research and publishing. Most respondents were male (57%), tenured (75%), had graduate faculty status (92%), had presented original research at conferences (85%), and had published articles in health education journals (89%). Faculty members were requested to assess whether 21 scenarios dealing with ethical issues in research and publishing were ethical, unethical, questionable, or not an ethical issue. Of the scenarios, 3 were considered ethical and 7 unethical by the majority of respondents. The perceptions of how ethical the remaining 11 scenarios were varied considerably. Perceptions of the ethical scenarios did not differ among respondents by sex, academic rank, years taught as a faculty member, whether the department taught units/classes on research ethics, or whether the respondents were from doctoral-level versus master’s-level programs.