| 71. |
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| 72. |
- Persson, Anders, 1953-
(författare)
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Postmortem Radiology
- 2010
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Ingår i: First World Congress of Forensic Science.
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Konferensbidrag (refereegranskat)
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| 73. |
- Persson, Anders, et al.
(författare)
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Radiation tolerance of a spin-dependent tunnelling magnetometer for space applications
- 2011
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Ingår i: Measurement science and technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 22:4, s. 045204-
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Tidskriftsartikel (refereegranskat)abstract
- To meet the increasing demand for miniaturized space instruments, efforts have been made to miniaturize traditional magnetometers, e. g. fluxgate and spin-exchange relaxation-free magnetometers. These have, for different reasons, turned out to be difficult. New technologies are needed, and promising in this respect are tunnelling magnetoresistive (TMR) magnetometers, which are based on thin film technology. However, all new space devices first have to be qualified, particularly in terms of radiation resistance. A study on TMR magnetometers' vulnerability to radiation is crucial, considering the fact that they employ a dielectric barrier, which can be susceptible to charge trapping from ionizing radiation. Here, a TMR-based magnetometer, called the spin-dependent tunnelling magnetometer (SDTM), is presented. A magnetometer chip consisting of three Wheatstone bridges, with an angular pitch of 120 degrees, was fabricated using microstructure technology. Each branch of the Wheatstone bridges consists of eight pairs of magnetic tunnel junctions (MTJs) connected in series. Two such chips are used to measure the three-dimensional magnetic field vector. To investigate the SDTM's resistance to radiation, one branch of a Wheatstone bridge was irradiated with gamma rays from a Co-60 source with a dose rate of 10.9 rad min(-1) to a total dose of 100 krad. The TMR of the branch was monitored in situ, and the easy axis TMR loop and low-frequency noise characteristics of a single MTJ were acquired before and after irradiation with the total dose. It was concluded that radiation did not influence the MTJs in any noticeable way in terms of the TMR ratio, coercivity, magnetostatic coupling or low-frequency noise.
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| 74. |
- Persson, Anders, et al.
(författare)
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Rapid prototyping of magnetic tunnel junctions with focused ion beam processes
- 2010
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP. - 0960-1317 .- 1361-6439. ; 20:5, s. 055039-
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Tidskriftsartikel (refereegranskat)abstract
- Submicron sized Magnetic tunnel junctions (MTJs) are most often fabricated by time-consuming and expensive e-beam lithography. From a research and development perspective, a short lead time is one of the major concerns. Here, a rapid process scheme for fabrication of micrometer size MTJs with focused ion beam processes is presented. The magnetic properties of the fabricated junctions is investigated in terms of magnetic domain structure, tunnelling magnetoresistance (TMR) and coercivity, with extra attention to the effect of Ga implantation from the ion beam. In particular, the effect of the implantation on the minimum junction size and the magnetization of the sensing layer are studied. In the latter case, magnetic force microscopy and micromagnetic simulations, with the Object Oriented Micromagnetic Framework (OOMMF), are used to study the magnetization reversal. The fabricated junctions show considerable coercivity both along their hard and easy axes. Interestingly, the sensing layer exhibit two remanent states: one with a single and one with a double domain. The hard axis TMR loop has kinks at about ±20 mT which is attributed to a non-uniform lateral coercivity, where the rim of the junctions, which is subjected to Ga implantation from the flank of the ion beam, is more coercive than the unirradiated centre. The width of the coercive rim is estimated to 160 nm from the hard axis TMR loop. The easy axis TMR loop shows more coercivity than an unirradiated junction and, this too, is found to stem from the coercive rim, as seen from the simulations. It is concluded that the process scheme has three major advantages. Firstly, it has a high lateral and depth resolution – the depth resolution is enhanced by end point detection – and is capable of making junctions of sizes down towards the limit set by the width of the irradiated rim. Secondly, the most delicate process steps are preformed in unbroken vacuum enabling the use of materials prone to forming oxides in the MTJ film stack. Thirdly, the scheme is both uncomplicated and quick and makes it possible to go from design to characterization in the order of hours.
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| 75. |
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| 76. |
- Persson, Anders, et al.
(författare)
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Samspel och spänningar mellan profession, styrning och kvalitet i lärarutbildningen
- 2010
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Ingår i: [Host publication title missing]. ; , s. 1-24
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Konferensbidrag (refereegranskat)abstract
- I föreliggande paper undersöker vi vad det innebär att lära till lärare i samspelet och spänningarna mellan profession, styrning och kvalitet. Mot bakgrund av det kvalitetsarbete vi i hög grad varit involverade i inom lärarutbildningen vid Högskolan i Halmstad frågar vi: Hur kan ett kvalitetsarbete inom en lärarutbildning utformas i spänningsfältet mellan extern styrning och professionellt handlingsutrymme? Först diskuteras lärares yrkesutövning ur ett professionsperspektiv. Därefter aktualiserar vi kort lärarutbildningens ställning i det svenska högre utbildningsväsendet med utgångspunkt från ett styrningsperspektiv. Slutligen redogör vi detaljerat för det kvalitetsarbete vi varit med om att utveckla inom lärarutbildningen mot bakgrund av en diskussion om hur kvalitet inom högre utbildning kan definieras. Slutsatsen blir att kvalitetsarbetet kan och bör avväga förhållandet mellan styrning och professionellt handlingsutrymme. Lärarutbildningen bör inom ramen för kvalitetsarbetet göra motstånd mot alltför detaljerad styrning till förmån för lärarens professionella handlingsutrymme.
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| 77. |
- Persson, Anders, et al.
(författare)
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Samverkan om fisk ger mervärde
- 2011
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Ingår i: Miljöforskning : Formas tidning för ett uthålligt samhälle. ; 2011:3
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 78. |
- Persson, Anders, et al.
(författare)
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Signs of resistance? Swedish probation officers’ attitudes towards risk assessments
- 2011
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Ingår i: European Journal of Probation. - 2066-2203. ; 3:3, s. 95-107
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Prison and Probation Service has been influenced by the „What Works‟ agenda since the late 1990‟s and an orientation towards risk and risk management has gradually become visible in the organization. But there is, within the probation service, a discrepancy between two types of logics – an organizational logic and a professional logic. Although guidelines prescribe the use of risk-assessment tools, they are in reality seldom used by practitioners. Through an examination of the reasons given by the probation officers who expressed doubts or concerns about the risk-concept, we question whether this could be seen as signs of resistance based on professional logic.
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| 79. |
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| 80. |
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