1. |
- Andersson, Å, et al.
(författare)
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The new 1.5 GeV storage ring for synchrotron radiation : MAX II
- 1995
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 66:2, s. 1850-1853
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Tidskriftsartikel (refereegranskat)abstract
- The MAX laboratory at Lund University, Sweden, today operates an accelerator system consisting of a 100 MeV racetrack microtron and a 550 MeV storage ring (MAX I). At the moment (July 1994) a new storage ring MAX II is near completion and will start first injections within 2 months. This work gives an overview of the MAX II project including the first beamlines and a description of the accelerator system. MAX II is a 1.5 GeV third generation light source optimized for the VUV and soft-x-ray region. It consists of a ten cell double bend achromat lattice forming the 90 m circumference ring. Injection is done at 500 MeV from the existing storage ring MAX I, and ramping up to full energy will take place in MAX II. The straight sections have a length of 3.2 m and eight sections are free to house insertion devices. At start up the ring will be equipped with one 7.5 T superconducting wiggler and one 1.8 T multipole wiggler. Two more undulators are ordered and under construction. To be able to achieve the project a few shortcuts have been made in the design of the storage ring: (1) Nonzero dispersion is allowed in the straight sections, (2) chromaticity correction is built into the quadrupole magnets, and (3) the length of the straight sections is limited to 3.2 m. The project is progressing on time. Extraction of an electron beam from the MAX I storage ring has been achieved and has successfully been transported into the MAX II building. The MAX II ring is under assembly with most of the sections already mounted. First injection is planned to take place in August 1994.
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2. |
- Ekström, Anna Mia, et al.
(författare)
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Occupational exposures and risk of gastric cancer in a population-based case-control study
- 1999
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Ingår i: Cancer Research. - 0008-5472. ; 59:23, s. 5932-5937
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Tidskriftsartikel (refereegranskat)abstract
- Gastric cancer trends seem to follow improvements in the environment of blue-collar workers, but the etiological role of occupational exposures in gastric carcinogenesis is scantily investigated. The risk of gastric adenocarcinoma in 10 common occupational industries, and particularly the long-term effects of asbestos, organic solvents, impregnating agents, insecticides, and herbicides, were evaluated in a population-based case- control study, including data on most established risk factors. The study base included all individuals of ages 40-79, born in Sweden and living in either of two areas (total population, 1.3 million) with differing gastric cancer incidences, from February 1989 through January 1995. We interviewed 567 cases classified to site (cardia/noncardia) and histological type, and 11(15 population-based controls, frequency-matched for age and sex. Metal workers had a 46% excess gastric cancer risk [adjusted odds ratio (OR), 1.46; 95% confidence interval (CI), 1.10-1.94], increasing to 1.65 (95% CI, 1.17- 2.32) for >10 years in the industry. The elevated risk after exposure to herbicides (OR, 1.56; 95% CI, 1.13-2.15) was attributable to phenoxyacetic acids (adjusted OR, 1.70; 95% CI, 1.16-2.48), similarly across tumor subtypes, and not modified by smoking, body mass index, or Helicobacter pylori. The absence of interaction was demonstrated by the pure multiplicative effect found among those exposed to both H. pylori and phenoxyacetic acids (OR, 3.42; 95% CI, 1.41-8.26). Organic solvents, insecticides, impregnating agents, and asbestos were not associated with gastric cancer risk. Employment in the metal industry and exposure to phenoxyacetic acids were both positively and independently associated with gastric cancer risk. The fractions of all gastric cancers attributable to these job-related exposures were small but not negligible (7 and 5%, respectively) in the Swedish population.
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3. |
- Engström, Johan, et al.
(författare)
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Method and device for the continuous cooking of pulp
- 1998
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Patent (populärvet., debatt m.m.)abstract
- This invention relates to a new and improved way of continuously cooking fibre material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimise chemical consumption and heat-economy and at the same time achieve very good pulp properties. The fibre material is heated and impregnated by the aid of black liquor to a temperature less than 140 .degree.C and passed in con- current in an impregnation zone (A). The heated and impregnated fibre material is transferred to a con-current cooking zone (B) in the upper part of a digester (6). At least 60 % of the quantity of liquor (F) required for the cooking reaction is supplied in the up-stream end of the con- current cooking zone (B) in order to obtain a level of effective alkali exceeding 35 g/l.; The cooking temperature in the con-current cooking zone (B) is lower than 160 .degree.C. Spent liquor (E), with an amount of effective alkali of at least 13 g/l, is withdrawn from a strainer girdle (8). A substantial part of the spent liquor is supplied to the impregnation zone.
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5. |
- Erlandsson, Marcus, et al.
(författare)
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Surveillance of Antibiotic Resistance in ICUs in Southeastern Sweden
- 1999
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Ingår i: Acta Anaesthesiol Scand. - : Wiley. ; 43:8, s. 815-820
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Tidskriftsartikel (refereegranskat)abstract
- Background: A study was designed to assess a computer-based program for continuous registration of antibiotic resistance, statistics concerning severity of illness, and consumption of antibacterial drugs. Methods: The frequency of antibiotic resistance among bacteria in eight ICUs in southeastern Sweden was investigated yearly from 1995 through 1997. The antibiotic consumption in the ICUs was registered as defined daily doses (DDD) and compared to severity of illness (APACHE-II scores). Results: There was a statistically significant increase in ampicillin resistance among Enterococcus spp. between 1996 and 1997, which was due to a shift from Enterococcus faecalis to Enterococcus faecium. A high prevalence of resistance among coagulase-negative staphylococci to oxacillin (≈ 70%), ciprofloxacin (≈ 50%), fucidic acid (≈ 50%) and netilmicin (≈ 30%) was seen in all ICUs during the whole study period. There was a statistically significant increase in ciprofloxacin resistance among Escherichia coli and Enterococcus spp. The resistance among Enterobacter spp. to cefotaxime decreased but this change was not statistically significant. Efforts were made to avoid betalactam antibiotics, except carbapenems, for treatment of infections caused by Enterobacter spp. and the consumption of cephalosporins decreased whereas the consumption of carbapenems increased. The total antibiotic consumption decreased by 2.5% during the study period. There was no correlation between APACHE II scores and antibiotic consumption. Conclusions: Each ICU within a hospital ought to have a program for "on-line" antibiotic resistance surveillance of drugs used in that unit so that changes in empirical treatment can be made when there is an increase in antibiotic-resistant isolates within that unit.
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6. |
- Gonzalo Epelde, I., et al.
(författare)
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Kinetics of wheat straw delignification in soda and kraft pulping
- 1998
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Ingår i: Journal of wood chemistry and technology. - : Informa UK Limited. - 0277-3813 .- 1532-2319. ; 18:1, s. 69-82
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Tidskriftsartikel (refereegranskat)abstract
- Kraft and soda delignification kinetics of wheat straw, Triticum aestivum, have been studied as a function of OH- concentration, HS- concentration, and temperature. It was found that about 90% of the lignin is dissolved in the rapid initial phase. The rates of delignification in the bulk and residual phases were found to be similar to those of birch wood, Betula pubescens, The amount of residual phase lignin was found to be considerably less than in birch or spruce, Picea abies, and it was affected by the same factors, A model that accurately describes the delignification of wheat straw was derived.
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8. |
- Karlsson, Lennart, et al.
(författare)
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Modeling of residual stresses and distortion development
- 1997
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Ingår i: Mathematical modelling of weld phenomena 3. - London : Institute of Materials. - 186125010X ; , s. 571-589
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Four examples are used to illustrate the current ability to calculate residual stress and distortion in situations of varying complexity. The methodology used is capable of allowing for interactions between thermal, mechanical, and transformation processes. Experimental values for a 2.25Cr-1Mo ferritic stainless steel were used in the simulation. It seems possible to simulate most welding situations given sufficient computer resources
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10. |
- Lindgren, C. T., et al.
(författare)
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The kinetics of residual delignification and factors affecting the amount of residual lignin during kraft pulping
- 1996
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Ingår i: Journal of Pulp and Paper Science (JPPS). - 0826-6220. ; 22:8, s. J290-J295
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Tidskriftsartikel (refereegranskat)abstract
- Kraft pulping of softwood can be divided into three phases: the initial, the bulk and the residual delignification phases. The rate of delignification in the residual phase and the amount of lignin to be removed in this slow phase have been studied as a function of the conditions in the kraft cooking of Norwegian spruce chips, Picea abies. The variables studied were concentration of OH-, concentration of HS-, ionic strength and temperature. The amount of lignin remaining undissolved in the wood residue at the transition from bulk to residual delignification is decreased by increasing the concentration of OH- and by increasing the concentration of HS- in the bulk phase. The amount of residual lignin is also decreased by a lower ionic strength in the bulk phase. The temperature in the range of 150 to 180 degrees C affected the lignin content at the transition from bulk to residual delignification but not the amount of residual lignin extrapolated to the beginning of the cook. Only the hydroxide ion concentration and the temperature seem to have an influence on the rate of delignification in the residual phase. The rate of delignification in the residual phase is well described by the following equation: dL(r)/dt = (0.0032 + 0.0020 . [OH-]) (. e) -146 000/8.314 . (1/T - 1/443.15)(Lr).
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14. |
- Lindgren, Per, et al.
(författare)
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Improved algorithms for efficient symbolic support set minimization
- 1995
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Ingår i: Proceedings / International Workshop on Logic and Architecture Synthesis. - : Institut National Polytechnique de Grenoble. ; , s. 38-44
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Konferensbidrag (refereegranskat)abstract
- We propose an improved algorithm for computing support sets for icompletely specified boolean functions. The problem to compute a compatible function with minimal support set, with respect to various criteria, arises in many applications, for example FPGA synthesis. By incorporating new lookup techniques together with lazy evaluation, we are able to prune the search space for possible mappings of the don't care set. We also suggest a new approach to the problem of support set minimization. The new algorithm computes the least specified compatible functions for all possible support sets up to 20 times faster than previous algorithms.
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15. |
- Lindström, Mikael, et al.
(författare)
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Cooking of pulp with high effective alkali concentration in the residual phase
- 1997
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Patent (populärvet., debatt m.m.)abstract
- A method and device for cooking pulp by increasing the effective alkali concentration in the residual phase of the cooking process to substantially improve the residual delignification rate and thus improving the pulp properties such as the pulp strength and pulp yield at a given lignin content.
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16. |
- Nordén, T, et al.
(författare)
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Mammographic screening for breast cancer : What cancers do we find?
- 1997
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Ingår i: European Journal of Cancer. - : Elsevier. - 0959-8049 .- 1879-0852. ; 33:4, s. 624-628
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare lymph node involvement of breast cancer cases detected at mammography screening with clinically-detected cases. During a 3-year period, 273 primary breast cancers were detected in a population-based screening programme, and 149 primary breast cancers were diagnosed clinically. Lymph node involvement was evaluated in univariate and multivariate logistic regression models correcting for tumour size, histological grade, steroid receptor status and DNA-ploidy. Patients with screen-detected cancers had a low relative risk of having lymph node metastases (univariate, OR = 0.31; 95% confidence interval = 0.19-0.52). In the multivariate logistic regression model, the relative risk was halved (OR = 0.47; 0.28-0.78). The reduced risk was more pronounced for women younger than 50 years of age compared to older women. The risk for screen-detected cases of having lymph node metastases at diagnosis was statistically significantly lower than for clinically-detected cases. The marked reduction, even when correcting for tumour size, makes it less likely that factors such as detection of clinically innocent tumours, length bias sampling or clinical symptoms related to axillary metastases can explain the whole difference. The results indicate at least part of the effect may be explained by tumour progression in the late preclinical detectable phase.
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17. |
- Stenberg, Georg, 1947-, et al.
(författare)
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Semantic processing of words without conscious identification : an ERP study
- 1998
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Ingår i: International Journal of Psychophysiology, vol. 30. no. 1-2. ; , s. 97-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This study examined the question whether semantic content can be accessed from words that are displayed under conditions (brief exposure, pattern masking) where they are not consciously identified. Thirty subjects performed a combined categorization and word identification task. Category labels (e.g. "fruit") were shown followed by masked, briefly exposed words, either validly cued by the category (e.g. "apple") or invalidly cued (e.g. "horse"). The subjects' task was to verify the category by pressing a button, and to identify the word by a verbal response. Exposure durations were selected to allow the subjects to identify approximately 50 % of the words. Four ERP averages were formed: for identified/unidentified words * validly/invalidly cued words. For identified words, there was a marked difference in the ERP response between validly and invalidly cued words. The difference was due to an N400 component for the invalidly cued words. For unidentified words, there was also a significant difference between validly and invalidly cued words, although smaller in size (23 % of that for the identified words). It had the same direction, and appeared in the same time range and with the same general topography as for the identified words. The results show that some semantic processing can operate on words that are not consciously identified
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20. |
- Werin, Sverker, et al.
(författare)
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New injector and storage ring for the MAX-laboratory
- 1999
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Ingår i: ; , s. 2945-2947
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Konferensbidrag (refereegranskat)abstract
- In December 1998 the FRN - The Swedish Council for Planning and Coordination of Research - decided to fund a new injector and storage ring for the MAX-laboratory. The system will consist of a 50-MeV linac, a 600-MeV booster synchrotron, and a 600-MeV storage ring for VUV undulator beamlines. The system will replace an old 100-MeV racetrack microtron and will inject the two existing storage rings: the 550-MeV MAX I and the 1.5-GeV MAX II, as well as the new 600-MeV storage ring. The linac injector will also be designed with intentions to provide electrons for a future infrared free-electron laser (IR-FEL) facility. The detailed design of the system began in January 1999 with a planned first beam in the summer of 2001.
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21. |
- Örtegren, Jonas, et al.
(författare)
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Time-dependent nonlinear optical properties of pyroelectric liquid crystalline polymers
- 1999
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Ingår i: Macromolecular Symposia. - : Wiley. - 1022-1360 .- 1521-3900. ; 148, s. 179-195
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Tidskriftsartikel (refereegranskat)abstract
- Highly oriented pyroelectric liquid-crystalline polymers were prepared by photopolymerization under the influence of a static electric field from binary mixtures of two acrylate monomers exhibiting chiral smectic C mesomorphism. Both monomers contained nitro groups to yield second order nonlinear optical properties (second harmonic generation) and one of the monomers had two functional groups to yield a crosslinked polymer. The room temperature second order nonlinear susceptibility of the polymers showed during the first two hours a 10 % decrease after which it remained constant during the next 48 days. At elevated temperatures there was a significant difference in the nonlinear optical properties over time between crosslinked and uncrosslinked polymers. The uncrosslinked polymer showed a pronounced loss of second order nonlinear optical activity with time at ≥38°C. The crosslinked polymer showed a much smaller and basically a temperature independent decrease rate in the second order nonlinear optical properties at all the ageing temperatures (23-130°C). Both the loss in mesogen order parameter, very evident for the uncrosslinked polymer, and conformational changes occurring within the mesogens (β mechanism), may account for the observations made.
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