Temperature dependence of spin-cluster resonance intensity in RbFeCl3·2H2O

The spin-cluster resonance intensity is observed as a function of temperature in the pseudo-one-dimensional canted Ising metamagnet RbFeCl3·2H2O. For T 0.7 TN a pure one-dimensional Ising model gives a good description of the observed intensities. For T TN the intensity decreases rapidly as a function of temperature due to the destruction of the local ordering around a spin-cluster. The measured value of the intrachain interaction Ja/k of -36 K is in good agreement with earlier measurements on spin-cluster excitations

Herhaalgedrag bij mensen met autisme en een verstandelijke beperking

Ruyter, P.A. de [Promotor]Joha, B.L. [Copromotor

A non-invasive cardiac output measurement as an alternative to the test bolus technique during CT angiography

Aim To investigate the association between a non-invasive cardiac output (CO) measurement and the scan delay, as derived from a test bolus injection protocol. The secondary objective was to determine which factors affect the relationship between the CO and scan delay. Materials and methods Fifty-five patients referred for a contrast-enhanced (thorax-)abdomen CT examination were included in this feasibility study. A test bolus examination was performed prior to the abdominal CT. During the test bolus injection, the CO of the patient was measured using a non-invasive finger-cuff measurement. Associations were analysed using linear regression analyses. Age, gender, height, weight, and blood pressure were included as potential confounders. Results Linear regression analysis showed a negative and significant association between CO and delay. The regression formula was as follows: scan delay (seconds) = 26.8–1.6 CO (l/min), with a 95% CI between −2.3 and −1.0 (p<0.001). Weight appeared to be a confounder in this relation, and gender and blood pressure were effect modifiers. There was no interaction between scan delay and age, height and weight. Conclusions There is a negative and significant association between the non-invasive CO measurement and the CT scan delay; however, to validate these findings a larger cohort study is needed to investigate whether the non-invasively determined scan delay is as accurate as the use of a test bolus