| 1. |
- Kristiansson, P., et al.
(författare)
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Optical dot gain on newsprint determined with the Lund nuclear microprobe
- 1997
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - Amsterdam : Elsevier. - 0168-583X .- 1872-9584. ; 130:1-4, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- A technique for measuring optical dot gain, i.e. the relative difference between the actual screen dot and the optically perceived one, is presented. By combining measurements from the non-optical nuclear microprobe with data from image analyzing technique the optical dot gain can be determined. The procedure to reach pixel by pixel correlation on a micrometer scale is discussed. In the newsprint sample studied in this investigation a typical optical dot gain between 15 and 20% was deduced. The variation in the optical dot gain was correlated with other characteristic parameters of the print and newsprint and especially a positive correlation to the mass density of the newsprint was observed. (C) 1997 Elsevier Science Ltd.
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| 2. |
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| 3. |
- Forslind, B., et al.
(författare)
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Elemental content of anagen hairs in a normal Caucasian population studies with proton induced X-ray emission (PIXE)
- 1986
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Ingår i: Scanning electron microscopy. - Chicago : IIT research institute. - 0586-5581. ; :Pt 1, s. 237-241
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Tidskriftsartikel (refereegranskat)abstract
- The elemental content of anagen hair fibers in a Caucasian population of healthy females and males in the age range 10-69 years was performed to constitute a baseline for further studies of pathological conditions. Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content. The hair fibers were all anagen hairs collected from a site little influenced by genetic and hormonal influences 1.5 cm above the right ear of the probands. An area 5-8 mm from the follicle bottom was chosen for the analysis in all cases to minimize effect of hair-do contamination. The average sulfur content was 0.049 g/g and the average zinc content 170 micrograms/g. These results were not significantly influenced by chloroform/ethanol rinsing before analysis. The calcium and chlorine contents were 330 micrograms/g and 0.0033 g/g respectively. The latter data are expected to be more seriously influenced by external factors (e.g., contamination) than sulfur and zinc. No correlation between elemental concentration and sex was found for sulfur and zinc in the present material. PIXE analysis of single hair fibers yields valuable information on the elemental composition of hair fibers and can be rapidly and efficiently performed after simple mounting procedures.
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| 4. |
- Forslind, Bo, et al.
(författare)
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Human skin physiology studied by particle probe microanalysis
- 1995
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Ingår i: Scanning Microscopy. - 0891-7035. ; 9:4, s. 1011-1025
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Tidskriftsartikel (refereegranskat)abstract
- Particle probe methods (electron probe and proton probe X-ray microanalysis) have been applied to investigate the distribution of elements and water over the different layers of the epidermis. For major elements, electron probe X-ray microanalysis (XRMA) provides the advantage of superior spatial resolution, but for trace element analysis the more sensitive proton probe (particle induced X-ray emission, PIXE) analysis has to be used. On a dry weight basis, the concentration of S is rather constant across the epidermis, whereas the concentrations of P, K, Cl and Na show gradients with high levels in stratum germinativum (basale) and stratum spinosum but low levels in the stratum granulosum and stratum corneum. Essentially, Fe and Zn are confined to the basal region in normal skin. The concentration of Ca, however, increased steadily from the basal region to the stratum corneum. The probe technique allows quantitative analysis of stratum-specific changes in elemental content in a variety of pathological conditions, e.g., changes induced by nickel, detergents and other chemicals, or in psoriatic skin. Of particular interest are findings of increased Fe and Zn in non-involved psoriatic skin. Since the different layers of the skin have different elemental concentrations and react differently under pathological conditions, the probe techniques are far superior to bulk chemical analysis in elucidating physiological and pathological processes in the skin.
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| 5. |
- Malmqvist, K. G., et al.
(författare)
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PIXE and proton microprobe advances at the Lund Institute of Technology
- 1989
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Ingår i: Nuclear Inst. and Methods in Physics Research, B. - 0168-583X. ; 40-41:PART 1, s. 685-689
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Tidskriftsartikel (refereegranskat)abstract
- A review of recent advances in high-energy ion beam analysis at the Lund Institute of Technology is presented. A nonvacuum specimen chamber allows chemical speciation using a combination of ion beam analysis and controlled heating. The development of a new versatile scanning proton microbeam based on a new dedicated accelerator, an achromatic triplet lens and an advanced specimen chamber is outlined together with the performance of a microVAX-II/VMEbus-based data acquisition system.
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