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| 5. |
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| 6. |
- Akselsson, Roland, et al.
(författare)
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Elemental Abundance Variation with Particle Size in Aerosols from Welding Operations
- 1974
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Ingår i: Proceedings of the Second International Conference on Nuclear Methods in Environmental Research. ; , s. 395-401
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Konferensbidrag (refereegranskat)abstract
- The effect of airborne particulate matter on human health is today of considerable research interest. Essential parameters include elemental composition sampling with low pressure cascade impactors and analysis by particle induced x-ray emission spectroscopy (PIXE). It is shown that the aerosol generated by arc welding operations is several orders of magnitude denser than aerosols in ambient air. Most of the mass is found on particles between 0.1 and 1µm diameter, but the size distribution differs from one welding technique to another. The relative composition of the aerosol is found to differ significantly from that of both the welding piece and the electrode indicating the presence of fractionation of the type indicated in this work in designing electrodes and welding pieces to minimize the health hazards associated with the welding.
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| 7. |
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| 8. |
- Akselsson, Roland, et al.
(författare)
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Luftföroreningar vid svetsning
- 1977
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- PIXE-analyser kan utföras med utvecklad analysuppställning med noggrannhet och precision av c:a 10 % och med hög analyskapacitet. Ett dataprogram för evaluering av räntgenspektra presenteras. Inverkan av provtjocklek vid PIXE-analys av inhomogena prov har studerats och korrektioner föreslås. Fluorinnehållet i filterprov har bestämts, samtidigt med PIXE-analys, genom utnyttjande av en kärnfysikalisk reaktion som ger resultat med god noggrannhet och precision. Svetsaerosoler har karakteriserats m.h.a. PIXE, ESCA och TEM/EDAX. En uppställning för insamling av svetsaerosoler under utveckling och hittillsvarande resultat indikerar representativ provinsamling med god reproducerbarhet.
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| 14. |
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| 15. |
- Arteaga, Natalia, et al.
(författare)
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The new cell irradiation facility at the Lund nuclear probe
- 2007
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 260:1, s. 91-96
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Tidskriftsartikel (refereegranskat)abstract
- The CELLION project is directed towards the studies on cellular response to targeted single ions. This paper gives an account of the modifications made at the Lund sub-micron beam line in order to create a Single Ion Hit Facility for biological applications within the CELLION project. The most relevant new feature is the specially developed software used to locate the cells. A program for cell recognition and localization that gives the coordinates of the centre of the cells has been designed. The recognition is made online. A picture taken by a microscope is used as input parameter for the recognition program. Using V79 Chinese hamster cells, the recognition procedure can be done in less than 0.5 s for a picture size of 800 x 600 pixels with approximately 96% efficiency. This paper also reports target accuracy test results and the first non-targeted irradiation procedure performed at the Lund sub-micron beam line. (c) 2007 Elsevier B.V. All rights reserved.
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| 16. |
- Auzelyte, Vaida, et al.
(författare)
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Fabrication of phosphor micro-grids using proton beam lithography
- 2006
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 242:1-2, s. 253-256
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Tidskriftsartikel (refereegranskat)abstract
- A new nuclear microscopy technique called ion photon emission microscopy or IPEM was recently invented. IPEM allows analysis involving single ions, such as ion beam induced charge (IBIC) or single event upset (SEU) imaging using a slightly modified optical microscope. The spatial resolution of IPEM is currently limited to more than 10 mu m by the scattering and reflection of ion-induced photons, i.e. light blooming or spreading, in the ionoluminescent phosphor layer. We are developing a '' Microscopic Gridded Phosphor '' (also called Black Matrix) where the phosphor nanocrystals are confined within the gaps of a micrometer scale opaque grid, which limits the amount of detrimental light blooming. MeV-energy proton beam lithography is ideally suited to lithographically form masks for the grid because of high aspect ratio, pattern density and sub-micron resolution of this technique. In brief, the fabrication of the grids was made in the following manner: (1) a MeV proton beam focused to 1.5-2 mu m directly fabricated a matrix of pillars in a 15 mu m thick SU-8 lithographic resist; (2) 7:1 aspect ratio pillars were then formed by developing the proton exposed area; (3) Ni (Au) was electrochemically deposited onto Cu-coated Si from a sulfamate bath (or buffered CN bath); (4) the SU-8 pillars were removed by chemical etching; finally (5) the metal micro-grid was freed from its substrate by etching the underlying Cu layer. Our proposed metal micro-grids promise an order-of-magnitude improvement in the resolution of IPEM.
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| 17. |
- Auzelyte, Vaida, et al.
(författare)
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The beam blanking system for microlithography at Lund Nuclear microprobe
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 485-489
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Tidskriftsartikel (refereegranskat)abstract
- A new beam blanking system was installed at the Lund Nuclear Microprobe and employed in proton beam lithography (PBL) for polymer microstructures fabrication. The blanker consists of two parallel plates connected to a high voltage generator. Measurement of the beam blanking time on a sample was performed by means of the standard PIXE system. The beam is blanked and returns to a sample within 200 ns. The blanking system is designed for the new sub-micrometer beamline under installation in the accelerator laboratory. A number of pilot MeV ion beam lithography experiments were performed to illustrate the possibility to use the blanking system in combination with the existing data acquisition and scanning system. A 2.5 MeV proton beam was used to irradiate 50 mum SU-8 negative resist. The blanker was shown to be a necessary part of the lithography system. It enables blanking between each pixel and hence fabrication of various patterns down to a single pixel. The blanker has significantly simplified beam control and enhanced process time and spatial resolution. Three-dimensional microstructures with 20:1 aspect ratio were fabricated.
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| 18. |
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| 19. |
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| 20. |
- Bohgard, Mats, et al.
(författare)
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Kontinuerliga tvåfraktionsinsamlare för övervakning av partikulära luftföroreningar i arbetsmiljö
- 1981
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten beskriver prototyper av kontinuerliga tvåfraktionsinsamlare för övervakning av partikulära luftföroreningar i arbetsmiljö som har konstruerats. En prototyp är personburen och ger möjligheter till insamling av två partikelstorleksfraktioner i 18 diskreta intervall. PIXE-metoden (analys med partikelinducerad röntgenstrålning) används för multielementanalys av de erhållna proven. Även med mycket korta insamlingstider, ner till 5 minuter, blir detektionsgränserna för de flesta element av yrkeshygieniskt intresse väsentligt lägre än sina respektive hygieniska gränsvärden. Rapporten inkluderar resultat från en enkel fältmätning som utgör ett exempel på de möjligheter den personburna provtagaren ger för yrkeshygieniska mätningar och undersökningar
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| 21. |
- Bohgard, Mats, et al.
(författare)
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MeV Protons for the Characterization of Aerosols in Work Environments
- 1981
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 459-463
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the advantages of accelerator-based chemical analysis of work environment aerosols are discussed. Use of the PIXE method is central, but in order to take full advantage of the possibilities of an accelerator laboratory, it should be combined with nuclear methods such as particle-induced nuclear reactions and/or particle scattering for simultaneous measurements of light elements. It is also important to develop optimum sampling techniques for the analytical methods required. Some information about the current set-up in Lund is given. In a companion paper, the potential of PIXE for work environment tasks is illustrated by a summary of the design of two major studies. Some results are also included.
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| 22. |
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| 23. |
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| 24. |
- Bohgard, Mats, et al.
(författare)
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Personal Aerosol Sampler with Size Fractionation and Time Resolution
- 1982
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Ingår i: Aerosols in the Mining and Industrial Work Environment. ; 3, s. 907-917
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter describes a personal aerosol sampler with size fractionation and time resolution that gives samples for elemental analysis. An impaction stage collects coarse particles and a filtration stage collects finer ones. Sampling in consecutive time intervals is performed on different impaction and filtration surfaces. These sampling surfaces corresponding, for example, to 15-min intervals, may be analyzed with particle-induced X-ray emission analysis (PIXE) for fast, low-cost determination of most of the elements of hygienic interest that are present in aerosols in concentrations far below their current threshold limit values (TLV). The sampler is intended to be used for aerosol measurements in work environments to obtain detailed information on exposures.
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| 25. |
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| 26. |
- Bulow, K, et al.
(författare)
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The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 189, s. 308-314
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Tidskriftsartikel (refereegranskat)abstract
- The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission, The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper, The dependence of the penetration depth on the pigment grain size was also Studied, To Study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used, For the study of the penetration depth dependence of pigment size. specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution, The results show that the calendering of the paper considerably affects the penetration depth of ink. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 27. |
- Carlsson, Lars-Eric, et al.
(författare)
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Karakterisering av svetsrök
- 1977
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Ingår i: Svenska Läkaresällskapets Riksstämma 1977, Omgivningshygien 11. ; , s. 443-443
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Konferensbidrag (refereegranskat)
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| 28. |
- Carlsson, Lars-Eric, et al.
(författare)
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Miljöanalys med hjälp av kärnfysikalisk teknik - PIXE
- 1981
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Ingår i: Ordo. - 0345-8970. ; 15:3, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- Under de senaste tio åren har en känslig analysmetod för grundämnen utvecklats vid institutionen för kärnfysik vid LTH. Metoden kallas PIXE (Particle Induced X-ray Emisson) och medger att mycket små förekomster (109 – 1012 g) av grundämnen kanbestämmas i små prov. Metoden är snabb. Ett par minuters analys ger en samtidig bestämning av ett stort antal grundämnen. Analysmetoden används nu i ett stort antal laboratorier runt om i världen och har funnit tillämpning inom en rad olika områden såsom medicin, biologi, yrkes- och omgivningshygien, meteorologi, geologi samt arkeologi. I Lund har metoden huvudsakligen använts för omfattande studier av föroreningar i arbetsmiljö och yttre miljö, varför vi först redogör för vårt arbete inom dessa tillämpningsområden, varefter vi beskriver de fysikaliska principerna för analysmetoden och utvecklingsarbetet med den.
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| 29. |
- Carlsson, Lars-Eric, et al.
(författare)
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PIXE Analysis of Samples of Intermediate Thickness
- 1981
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 179-183
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Tidskriftsartikel (refereegranskat)abstract
- A procedure for making accurate matrix corrections in PIXE analyses of samples of intermediate thickness has been developed. The transmission of a collimated X-ray beam through different parts of the sample is measured with a Si(Li) detector to determine the thickness and shape of the sample. Experiments have been performed using uniform polymer foils doped with known concentrations of different elements and with thicknesses ranging from 1.5 to 11 mg/cm2. The results from these samples indicate that the accuracy of the correction procedure is better than 5%. The correction procedure has been applied to, e.g., samples obtained in single orifice cascade impactors.
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| 30. |
- Elfman, Mikael, et al.
(författare)
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The Lund Nuclear Microprobe sub-micron set-up. Part III: Sample stage, optical imaging and detector configuration in the experimental chamber
- 2005
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 231:1-4, s. 14-20
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Tidskriftsartikel (refereegranskat)abstract
- A new sub-micron beamline for high-resolution nuclear microprobe applications has been constructed at the Lund nuclear microprobe facility. The design and construction of the main experimental chamber.. sample viewing system and computer controlled precision sample stage movement is presented in this paper. The chamber is especially designed for using a large area annular HPGe detector. The advantages with such a large area detector are discussed and illustrated. In addition the quality of the optical viewing and the precision sample stage is discussed.
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| 31. |
- Forslind, Bo, et al.
(författare)
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Elemental Analysis on Freeze-Dried Sections of Human Skin: Studies by Electron Microprobe and Particle Induced X-Ray Emission Analysis
- 1984
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Ingår i: Scanning Electron Microscopy. - 0586-5581. ; , s. 755-759
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of using the proton microprobe (PMP) in the elemental analysis of dermatological material, under conditions where the spatial resolution can be restricted to a few micrometers, was demonstrated. Comparison with the electron microprobe (EMP) technique using duplicate sections from the same human skin biopsies revealed that the PMP and EMP techniques are complementary and yield closely corresponding elemental distributions for elements of dermatological interest. The concentrations of phosphorus and potassium were low in the dermis, high in the stratum basale and stratum spinosum, and decreased markedly in the stratum granulosum to a low level in the stratum corneum. The sulfur concentration was highest in the stratum corneum.
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| 32. |
- Glave, Stefan, et al.
(författare)
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Quality indicators for woodwind reed material
- 1999
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 150:1-4, s. 673-678
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Tidskriftsartikel (refereegranskat)abstract
- For the generation of sound, some woodwind musical instruments, e.g. oboe, bassoon, clarinet and saxophone, are provided with mouthpieces made from reeds. These reeds are the culms of Arundo donax, a tall, cane-like perennial grass. A general problem is that the material is of varying quality, yet externally differences cannot be observed. Hence, large proportions of the prepared reeds are unusable. One hypothesis is that the changes in quality are correlated with differences in the chemical and anatomical structure of the tissue. Therefore, a comparison of superior and inferior mouthpieces, used by professional musicians, was undertaken to determinate potential indicators of quality. Nuclear microprobe analysis of reeds was carried out and complemented by scanning electron and light microscopy. The elemental levels of Si, P, S, Cl, K and Ca were compared between good and poor mouthpieces using appropriate statistical tests. No statistically significant differences could be identified. Microscopical observations showed that partial occlusion of vessels by tylose formation was associated with material deemed unusable.
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| 33. |
- Golubev, Pavel, et al.
(författare)
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First results from the Lund NMP particle detector system
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 267:12-13, s. 2065-2068
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Konferensbidrag (refereegranskat)abstract
- The design and first results from a Double Sided Silicon Strip Detector (DSSSD) recently installed at the Lund Nuclear Microprobe facility (NMP) are presented. The detector has 64 sector strips and 32 ring strips, which in combination give more than 2000 detector cells, each with characteristics comparable with a standard surface barrier detector (SBD). The detector has been tested both with radioactive sources and with different ion beams and energies. The most striking features are the high rate virtually pile-up free operation and also the possibility of detailed measurement of angular distributions. (C) 2009 Elsevier B.V. All rights reserved.
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| 34. |
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| 35. |
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| 36. |
- Johansson, Gerd, et al.
(författare)
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Calibration and Long-Term Stability of a PIXE Set-Up
- 1981
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 81-88
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Tidskriftsartikel (refereegranskat)abstract
- A general mass calibration procedure of a PIXE set-up is described. As an example, the results of the calibration of the PIXE set-up in Lund are given. For the calibration commercially available standards were used. The parameters of a physical model were adjusted to fit a calibration curve. To decrease errors due to inhomogeneities of the standard foils, the average from four different pieces of each foil was taken. The accuracy of the calibrated system in Lund is estimated to be better than 5% for individual elements and still less for ratios of adjacent elements. For long-term quality control of the results, a special sample has been designed. This consists of a thick silver plate with a small copper spot in the centre. It is very sensitive to small changes in a PIXE set-up. By analysing this sample periodically, mistakes in the arrangement are promptly detected-a feature which is much appreciated in a mixed research, development and routine analysis laboratory. Also a measure of the long-term stability is obtained. For the Lund system, the long-term stability is 2.5% for a homogeneous sample and 4% for a small (inhomogeneous) sample.
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| 37. |
- Johansson, Gerd, et al.
(författare)
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Characteristics of Welding Fumes
- 1981
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aerosols from 13 common electric arc welding processes have been characterized regarding total emission, particle size distribution, elemental composition and, when applicable, the oxidation state of chromium. The characterizations have been performed systematically for different combinations of welding current and welding voltage.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Johansson, Gerd, et al.
(författare)
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Luftföroreningar vid svetsning
- 1978
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Beskrivning ges av utveckling av analysuppställning för PIXE-analys, kombinerad med metod för analys av fluor. Vidareutveckling av spektrumevalueringsprogram, HEX, presenteras. Beskrivning av utförda svetsröskarakteriseringar ges. Resultat redovisas för följande belagda elektroder: OK 48.00, OK 38.65 samt OK 61.41. För sistnämnda, rostfria elektrod, presenteras procedur för bestämning av kroms valenstal och löslighet.
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| 42. |
- Johansson, Gerd, et al.
(författare)
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Particle-Induced X-Ray Emission: A Useful Analytical Method
- 1978
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Ingår i: Proceedings of Analyt. Div. Chem. Soc.. ; 15, s. 24-27
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Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedIn 1970, it was shown experimentally by Johansson et al. that the excitation of atoms by charged particles, e.g. protons, and the subsequent detection of the induced X-rays by an energy-dispersive detector constitutes a non-destructive multi-elemental method with low detection limits and several other properties desirable in an analytical method. Since then, many investigations have been performed and the method, known as particle-induced X-ray emission (PIXE), has been developed further. The development of suitable methods of pretreating samples for PIXE analysis has also been intensively pursued. In the Proceedings of the International Conference of Particle-induced X-ray Emission, the method and its applications are thoroughly reviewed. Two reviews have also recently been published.In this summary, the principles and properties of PIXE are discussed. Possible areas of application are briefly discussed, and limits of detection of elements in blood plasma are considered.
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| 43. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Johansson, Thomas B, et al.
(författare)
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Analytical Use of Proton-Induced X-Ray Emission
- 1976
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731. ; 32:1, s. 207-217
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Tidskriftsartikel (refereegranskat)abstract
- Proton-induced X-ray emission, PIXE, is capable of simultaneous quantitative determination of 10-15 elements. An introduction to the physical properties of the method is given and detection limits are shown for a routine analysis of a thin aerosol sample. Examples of applications to both thick and thin samples are presented. Human tooth dentine is analysed for lead, with simple sample preparation, indicating lead values of a few ppm for Swedish children. Quantitative analyses of several other elements are obtained simultaneously. Cascade impactors axe used for sampling aerosols in work environment during welding operations giving information of size distribution and concentrations of the elements present. The aerosol is dominated by particle sizes between 0.5 and 2 um as measured by the impactor, but the size distributions are different for different elements and welding techniques and depend on the distance from the welding source. The relative abundance of the elements found in the aerosol indicates the presence of fractionation mechanisms.
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| 48. |
- Johansson, Thomas B, et al.
(författare)
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Analytical Use of Proton-Induced X-Ray Emission
- 1975
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Ingår i: Trans Am Nucl Sci; Proceedings: Summary on a lecture at the International Nuclear and Atomic Activation Conference and the 19th Annual Meeting on Analytical Chemistry in Nuclear Technology. ; 21, s. 31-31
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Konferensbidrag (refereegranskat)
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| 49. |
- Kristiansson, Per, et al.
(författare)
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Development of a system for determination of the C-13/C-12 isotopic ratio with high spatial resolution
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 561-566
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Tidskriftsartikel (refereegranskat)abstract
- Stable carbon isotopes play an important role in the interpretation of biological activity, particularly when the fossil record is studied. In combination with morphological and chemical data, isotopic information can be useful in paleontology and astrobiology. In this paper the development of a microanalytical ion beam system for the measurement of the carbon isotope ratio with high spatial resolution and good statistics is presented. The technique used is elastic scattering of alpha particles with an energy of 2.75 MeV. At this energy the C-13 cross-section is enhanced relative to the Rutherford cross-section and while the C-12 cross-section is reduced. The optimisation of the system is described, including sample preparation and the design of the particle detection system for high efficiency combined with good energy resolution. Finally, some results from the initial test run of the system are shown and discussed. (C) 2004 Elsevier B.V. All rights reserved.
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| 50. |
- Li, Hong-Kou, et al.
(författare)
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A PIXE System for Routine Longitudinal Scanning of Single Hair Strands
- 1984
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 3:1-3, s. 347-351
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Tidskriftsartikel (refereegranskat)abstract
- This article describes a PIXE system designed and constructed for routine longitudinal scanning of single hair strands. In constructing a PIXE system for trace elemental scans of single hair strands on a routine basis, a fairly intense beam has to be used but the heating damage must be kept to a minimum. The experimental conditions (charge integration, beam homogeneity etc.) have to be carefully controlled in order to give accurate PIXE results. The geometrical thickness of the hair at each point of the scan has to be determined and a qualitative knowledge of the elemental distribution over the cross section of the hair has to be provided for a proper interpretation of the PIXE results. In the present PIXE system the geometrical thickness of a hair strand at each point along the scan is determined by counting the number of backscattered protons simultaneously with the PIXE analysis, and a qualitative knowledge of the elemental distribution over the cross section of the hair is obtained through bombarding the hair at particular points with different proton energies.
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