Elemental analysis of whole blood using proton-induced X-ray emmission.
A technique for the analysis of trace elements in whole blood was developed using proton-induced x-ray emission. Samples of 0.1 ml whole blood from humans and mice were dried, weighed, and then ashed in a plasma asher. Targets were prepared by placing drops made from the ash and a 100-ppM Pd solution onto Formvar backings. The samples were irradiated with 2.25-MeV protons, and the x-rays analyzed in a nondispersive x-ray detector. The elements Fe, Cu, Zn, Se, and Rb were detected with a precision of 7, 18, 7, 50, and 19%, respectively, in human whole blood. The precision of the technique was determined by statistical analyses of two different sets of 27 samples. The system was found to be linear for variations in elemental concentration. The accuracy for deterrmination of Zn was found to be within 10% by comparison to atomic absorption spectrometry.
The Preparation of Large Plastic Films for Proportional Counter Windows
The preparation of thin and uniform plastic films for rocket‐borne x‐ray proportional counters is described. The technique has produced entrance windows of 60 μg/cm2 thickness and 700 cm2 in area.
Review of Literature on Probability of Detection for Magnetic Particle Nondestructive Testing
Abstract : A critical review of the available literature concerning the minimum reliably detectable defect size aNDI for magnetic particle testing (MPT) in aerospace applications is presented. Four probability of detection (POD) studies relevant to detection of fatigue cracks in aircraft components were found over the period 1968 to 2011. As the statistical methods used in these four previous studies were either outdated or otherwise deficient, the original data were reanalysed using currently accepted techniques. A meta-analysis of the results is presented, with emphasis on statistical inferences for the defect size expected to be detected with 90% POD. It is shown that the minimum reliably detectable defect size aNDI = 2.0 mm currently specified by the Royal Australian Air Force for wet fluorescent magnetic particle inspection using the continuous method is consistent with estimates of the average performance of MPT derived from the reanalysis of the literature.