The interesting functions of additives in NiZn-ferrite
introduction Additives play a quite significant roll in microwave ferrites. Proper sorts and quantities of additives can improve aany important characteristics of materials. In this paper, two kinds of additives,NW and cd). are discxlssed about their effects on tk remanent ratios R of NiZn ferrites used in milliaeter-wave band. Both of them can enhance R efficiently so that they are beneficial to latching device applications. The mechanism is discussed qualitativeiy.At the same tile,scnoe interesting attendent phenomena are rqnrted. ExDeriments The specimens were prepared with wnventional ceramic process with the composition as follows: NILCo. Zb., CU, Bim Nb. & Fel.s 0, (1) The B-Hloops were traced with a YEW W e 1 3251 Auto Tracer. The raoanent ratics +R/R were read off the loops of sa!41ples,whose mercive forces were around 80 A/m (1 Ce), with the magnetizing field H,-3Z@A/n(40 Oe).B and B, are residual and saturation inductions,respectively.
Magnetostriction of Ni-Zn ferrites containing cobalt
Abstract The influence of a small cobalt content on the magnetostriction of Ni-Zn ferrites has been investigated and is discussed. It is shown that, as in the case of a magnetocrystalline anisotropy, the value of λ s may in this case be quite different from that expected. The results prove that, in spite of common opinion, there are no “piezomagnetic obstacles” to introducing Co ions into Ni-Zn ferrites, when the diminishing of their magnetic loss factor in high frequency range is needed.
School Principals and Education Law: What do they know, what do they need to know?
Principals now work in complex and challenging environments where uncertainty and change are the hallmarks of their roles and responsibilities. As such, the knowledge and capability demands on principals have expanded, including those related to education law. While these matters attracted some research interest a number of years ago, there has been little recent work in the area of principals and education law. This article reports on an exploratory study into aspects of the legal knowledge held by Tasmanian government school principals, particularly concerning non-sexual physical contact between teachers and students. The research was undertaken using a small-scale, mixed-methods research design, which required principals to respond to various legal scenarios. Three key findings emerged from the study. First, principals used two different levels of working knowledge about education law  one related to legal problems, and the other to legally-related routine activities. Second, on the particular topic of physical contact, some knowledge held by principals was not legally accurate. Third, for major legal issues, participants indicated that they acquired access to information from legal experts. The situation for routine legal matters was less clear, although in-service training and practical experience were identified as potential sources of knowledge. Participants recognised the importance of a sound knowledge of education law, especially for dealing with security and safety issues and preferred to access further information through in-service training. Notably, the findings of the study are broadly consistent with those from earlier Australian and international research, suggesting that much remains to be done in the area of principals’ education law knowledge.