English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Background: Data fitting approaches to modeling allow for parametric formulaethat may not reveal the physical quantities involved and their influence on thefunction being studied. In this paper the author models the approach toequilibrium function by a method that allows the physical quantities to bedefined beforehand, allows their influence to be studied, and can be used topredict how each physical quantity affects approach to equilibrium. Methods: Anordinary differential equation (ODE) is used to model the approach toequilibrium function for the case where collimation is changed at fixeddetector size. A parallel model is used to study the approach to equilibrium asa function of detector size for fixed collimation. Both models are validated byexperimental measurements in a 60cm body phantom. Influence of detector size issimulated by using leaded sleeves of varying sizes wrapped around a 100mmpencil chamber. This creates sleeve gaps of 10 - 60mm around the chamber. A100mm detector size is the pencil chamber without a leaded sleeve. Results:Model accurately describes the experimental data for the cases studied. Exceptfor the smallest collimation of 5mm, linear regression analysis shows goodcorrelation between data and model according to the R^2 values at allcollimations. Further analysis of the model reveals minimum detector size thatwill integrate 98% of the signal for a given collimation is, d=4.95L.Additional analysis shows the minimum collimation at which a given detectorwill collect 98% of the signal is, L=5.49d. Conclusion: Modeling bydifferential equations is an accurate method for the approach to equilibriumfunction, and has advantages over curve fitting methods.

Influence of Collimation and Detector length on CT exposures measured in a 60cm long body phantom