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Radio frequency (RF) technology relies on the electromagnetic properties of the materials used, which includes their complex permittivities and loss tangents. To measure these properties, techniques for material characterization such as the transmission/reflection method are used in conjunction with conversion techniques to calculate these values from scattering parameters. Unfortunately, these techniques rely on relatively expensive rectangular waveguide adaptors and components, especially if testing over large frequency ranges. This paper aims to overcome this challenge by developing a more affordable test equipment solution based on additively manufactured waveguide sections.

To evaluate the effectiveness of using additively manufactured waveguides to perform electromagnetic characterization with the transmission/reflection method, samples of PLA Tough with varying infill percentages and samples made from several Formlabs photopolymer resins are fabricated and analyzed.

Results show that the method yielded permittivity and loss tangent values for the measured materials that generally agree with those found in the literature, supporting its credibility.

The accessibility of this measurement technique will ideally allow for more electromagnetic material characterization to occur and expand the possible use of additive manufacturing in future RF designs. This work also provides characterization of several Formlabs photopolymer resins, which have not been widely analyzed in the current literature.

Weeding is, among all of the tasks common in librarianship, one of the most rife with conflict. The purpose of this chapter was to examine the emotions and emotional impact of deselection on librarians and library staff using a framework of weeding styles. The authors did a qualitative survey-based case study. They created a survey using Google Forms and deployed it to five library-related listservs and one Facebook group. All of the questions were mandatory, except for the open-answer questions. The authors also conducted an extensive literature review. The survey revealed a more harmonious practice than the literature might indicate. There were some noteworthy correlations drawn among weeding styles, emotions, and the practice of weeding. The authors discuss the implications of their findings and ideas for future research. They also provide strategies and recommendations in terms of communication in the course of deselection and how to handle emotional labor in the workplace. A literature review conducted by both authors did not reveal any other examination of this type. The chapter will fill a gap in the literature.