Application of Counter-wound Multi-arm Spirals in HTS Resonator Design.

Significant sensitivity improvements have been achieved by utilizing high temperature superconducting (HTS) resonators in nuclear magnetic resonance (NMR) probes. Many nuclei such as 13C benefit from strong excitation fields which cannot be produced by traditional HTS resonator designs. We investigate the use of double-sided, counter-wound multi-arm spiral HTS resonators with the aim of increasing the excitation field at the required nuclear Larmor frequency for 13C. When compared to double-sided, counter-wound spiral resonators with similar geometry, simulations indicate that the multi-arm spiral version develops a more uniform current distribution. Preliminary tests of a two-arm resonator indicate that it may produce a stronger excitation field.

Progress Towards a Higher Sensitivity 13C-Optimized 1.5 mm HTS NMR Probe.

Nuclear magnetic resonance (NMR) probes using thin-film high temperature superconducting (HTS) resonators offer high sensitivity and are particularly suitable for small-sample applications. We are developing an improved 1.5 mm HTS NMR probe designed for operation at 14.1 T and optimized for 13C detection. The total sample volume is about 35 µL and the active sample volume is 20 µL. The probe employs HTS resonators for 13C and 1H transmission and detection and the 2H lock. We examine the interactions of multiple superconducting resonators and normal metal tuning loops on coil resonance frequency and probe sensitivity. We test a recently introduced 13C resonator design, engineered to significantly increase 13C detection sensitivity over previous all-HTS probes. At zero field, we observe a 13C quality factor of 6000 which is several times higher than previous resonators. In this work the coil design considerations and probe build-out procedure are discussed.

Is Bondage and Discipline, Dominance and Submission, and Sadomasochism Recreational Leisure? A Descriptive Exploratory Investigation.

INTRODUCTION: Recent studies have suggested that, in contrast to traditional psychopathologic explanations, bondage and discipline, dominance and submission, and sadomasochism (BDSM) could be understood as recreational leisure. However, the theoretical framing of BDSM as potential leisure has not been empirically explored. AIM: To conduct an initial empirical exploration to determine whether BDSM experience fits established characteristics of recreational leisure. METHODS: A convenience sample of BDSM participants (N = 935) completed an online survey (9 demographic questions and 17 leisure questions) that assessed BDSM experience according to important attributes of leisure. Responses also were assessed and statistically compared as being primarily casual or serious leisure according to general BDSM identities (ie, dominants vs submissives vs switches). MAIN OUTCOME MEASURES: BDSM experiences were assessed as a form of potential leisure. RESULTS: Most BDSM experiences met leisure criteria. Participants reported that "most of the time or nearly always" BDSM was associated with a sense of personal freedom (89.7% of participants), pleasure or enjoyment (98.5%), sense of adventure (90.7%), use of personal skills (90.8%), relaxation or decreased stress (91.4%), self-expression or exploration (90.6%), and positive emotions (96.6%). BDSM seemed to function as primarily serious, rather than casual, leisure, but important statistical differences were observed based on specific BDSM identities. CONCLUSION: A leisure science perspective could be valuable to researchers and clinicians in reinterpreting the wide range of diverse BDSM motivations and practices.