Characteristics of a production route for filamentary Nb3Sn superconductors based on a reaction between niobium and Nb6Sn5

Monofilamentary Nb3Sn superconductors have been made by application of a reaction between Nb6Sn5 powder and niobium. The layer thickness of Nb3Sn shows a parabolic time dependence, implying diffusion-controlled layer growth. The activation energy for diffusion is 268 kJ mol−1. The critical temperature Tc is about 17.5 K and the overall critical current density Jc is about 5 × 108 A m−2at 8 T, both after annealing at 675 °C. These values are comparable with those obtained for so-called ECN-type superconductors, which are based on a reaction between NbSn2 powder and niobium. An advantage of the use of Nb6Sn5 powder in comparison with NbSn2 is the kinetics of growth of Nb3Sn, which allows a lowering of the reaction temperature to 600–625 °C for filament diameters of about 30 μm

Experiences of service users with a mild intellectual disability or borderline intellectual functioning with Flexible Assertive Community Treatment:A qualitative study

Background In the Netherlands, Flexible Assertive Community Treatment (FACT) teams have been established for people with mild intellectual disability (MID) or borderline intellectual functioning (BIF) and mental health problems or challenging behaviour. Little is known yet about service users’ experiences with FACT. Method An inductive grounded theory approach was used to explore how service users valued the treatment and their own functioning, and which factors were perceived as supportive. Semi‐structured interviews were held with 15 service users. Results Most service users highly appreciated the contact with the staff and the practical and emotional support. Persistent involvement, availability and humanity, and respect for autonomy were distinguished as core values in the relationship with the staff. Most service users experienced improvement in time and attributed this to intrapersonal changes and/or less stress in life. Conclusions From the perspective of service users with MID/BIF, FACT appears to have an added value

Poststroke Fatigue and Daily Activity Patterns During Outpatient Rehabilitation:An Experience Sampling Method Study

OBJECTIVE: To advance our understanding of poststroke fatigue by investigating its momentary and time-lagged relationship with daily activities.DESIGN: Longitudinal observational study using the experience sampling method (ESM).SETTING: Outpatient rehabilitation care.PARTICIPANTS: Thirty individuals with stroke (N=30).INTERVENTIONS: Not applicable.MAIN OUTCOME MEASURES: ESM is a structured diary method that allows assessing real-time symptoms, behavior, and environment characteristics in the flow of daily life, thereby capturing moment-to-moment variations in fatigue and related factors. Using a mobile application, individuals with stroke were followed during 6 consecutive days, and were prompted at 10 random moments daily to fill in a digital questionnaire about their momentary fatigue and current activity: type of activity, perceived effort and enjoyment, and physical activity levels.RESULTS: Based on all completed digital questionnaires (N=1013), multilevel regression analyses showed that fatigue was significantly associated with type of activity and that fatigue was higher when participants had engaged in physical activity. Fatigue was also higher during activities perceived as more effortful and during less enjoyable activities. Time-lagged analyses showed that fatigue was also predicted by physical activity and perceived effort earlier during the day. Importantly, the relationship between these daily activity characteristics and fatigue differed substantially across individuals.CONCLUSIONS: This study illustrates the need for ESM to design personalized rehabilitation programs and to capture fatigue and other patient-reported outcomes in daily life.</p

A Review of the Properties of Nb3Sn and Their Variation with A15 Composition, Morphology and Strain State

This article gives an overview of the available literature on simplified, well defined (quasi-)homogeneous laboratory samples. After more than 50 years of research on superconductivity in Nb3Sn, a significant amount of results are available, but these are scattered over a multitude of publications. Two reviews exist on the basic properties of A15 materials in general, but no specific review for Nb3Sn is available. This article is intended to provide such an overview. It starts with a basic description of the Niobium-Tin intermetallic. After this it maps the influence of Sn content on the the electron-phonon interaction strength and on the field-temperature phase boundary. The literature on the influence of Cu, Ti and Ta additions will then be briefly summarized. This is followed by a review on the effects of grain size and strain. The article is concluded with a summary of the main results.Comment: Invited Topical Review for Superconductor, Science and Technology. Provisionally scheduled for July 200