Impulse irradiation of layered medium by the open end of circular waveguide
The radiation of impulse signal from the open end of a circular waveguide is considered by analytical and direct numerical methods. The radiation of short pulse from the aperture is considered by calculation of special time form of field by means of modal basis method that permits to transform the nonstationary three-dimensional electrodynamic problem into the problem for one-dimensional evolutionary equations by means of the construction of modal basis for electromagnetic field with arbitrary time dependence. The method is applied to solve the problem of pulse evolution for positive and negative time with the use of Laplace transform by construction of operator of propagation. The approach is employed to form the short pulse on aperture of circular waveguide for irradiation of layered medium with losses.
Transient radiation from the open end of circular waveguide
The transient radiation from the open end of a circular waveguide is considered by simple analytical and direct numerical methods. The radiation of short pulse from the aperture is provided by calculation of special time form of field by means of modal basis method that permits to solve the problem of pulse evolution for positive and negative time with the use of Laplace transform. The radiation of the short pulse is calculated in Kirchhoff approximation and simulated by FDTD method. The frequency characteristics of the radiated field are considered.
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.