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91.
Jenni Karlsson 《Pedagogy, Culture & Society》2004,12(3):327-346
In setting out to understand how South African school space was harnessed to the political project of apartheid, the author explores memory accounts from several adults who attended school during the apartheid era. Her analysis of their reminiscences found that non-pedagogic areas of the school and public domain beyond school premises were places where learners encountered their Other. Those sites provided the conditions for poignant awakenings to racialised identifications within discriminatory hierarchies. The article ends with the author reflecting on the effectiveness of spatially segregated schooling, when she works towards understanding her informants' uncritical tributes to the educational and moral value of their apartheid-era schooling. 相似文献
92.
Ö. H. Andersson K. H. Karlsson H. Hero E. Vedel A. Yli-Urpo K. J. J. Pajamäki T. S. Lindholm 《Journal of materials science. Materials in medicine》1995,6(4):242-247
Glass compositions for double coatings for a Co-Cr-Mo alloy were developed. The glass compositions were chosen to fulfil such requirements as matching thermal expansion, low glass transition temperature and moderate solubility. For the ground coat a fairly high durability is required, whereas the cover coat must be bioactive, i.e. become attached to living bone by a chemical bond. Two compositions of each type were developed by computer-aided optimization. The glasses were chosen in the Na2O–CaO–B2O3–Al2O3–SiO2–P2O5 system. The bioactivity was tested in vitro by immersion in a simulated body fluid. The double coatings on Co–Cr–Mo alloy released hexavalent chromium into the solution as detected by yellow colouration and spectrophotometry. This colouration was strong at the margin between coated and uncoated metal and may be explained by oxidation of trivalent chromium of the alloy in the presence of glass. The released chromium did not have any notable effect on the calcium phosphate formation. After replensihing the solution no coloration was observed. This suggests that the chromate is easily dissolved and that it may be possible to wash it out prior to implantation. 相似文献
93.
In a Combined Heat and Power (CHP) network, it is sometimes optimal to install a device for storing heat from one period of time to another. Several possibilities exist. If the electricity demand is high, while at the same time the district heating load is too small to take care of the heat from the CHP plant, it could be optimal to store heat from peak periods and discharge the storage under off-peak. It might also be optimal to store heat during off-peak and use it under the district heating peak load. The storage is then used for decreasing either the district heating demand or for decreasing the electricity load used for space heating. The paper shows how a mixed integer program is developed for use in the optimization process. As a case study, the CHP system of Malmö, Sweden, is used. Further, a sensitivity analysis is elaborated in order to show how the optimal solution will vary due to changes in certain input data. 相似文献
94.
A method to estimate the annual collected energy and the annual average optical efficiency factor is suggested. The radiation distribution on the absorber of an asymmetric CPC collector with a flat bi-facial absorber is measured for three different absorber mounting angles using a photo diode. The annual optical efficiency factors and a relative measure of the annual collected energy are determined for collectors with the absorber fin thickness 0.5 and 1 mm, and for a collector with a teflon convection suppression film mounted around the absorber. With the local optical efficiency factors and the annual incident solar energy distribution considered, the analysis indicates that the energy gain for a mounting angle of 20° is higher than for a collector with 65° absorber mounting angle. The annual collected energy is increased with 6–8% if the absorber fin thickness is increased from 0.5 to 1 mm. The annual average optical efficiency factor is relatively independent of the absorber mounting angle. It was found to be 0.87–0.88 for a collector with a 0.5 mm thick absorber fin and 0.92 for a collector with a 1 mm thick absorber fin or for a collector with 0.5 mm thick absorber fin with a teflon convection suppression film added. The low annual average optical efficiency factor is not caused by the uneven irradiance distribution but by the relatively high UL-values. 相似文献
95.
96.
Yolanda HedbergOskar Karlsson Peter SzakalosInger Odnevall Wallinder 《Materials Letters》2011,65(14):2089-2092
Electron Backscatter Diffraction (EBSD) studies clearly revealed a different crystallographic structure of the smallest particle size fraction of gas-atomized AISI 316 L stainless steel powder (< 4 μm) compared with larger sized fractions of the same powder (< 45 μm). Despite similar chemical compositions, the predominating structure of the smallest particle size fraction was ferritic (i.e., has ferromagnetic properties) whereas the larger sized particle fractions and massive 316 L revealed an expected austenitic and non-magnetic structure. From these findings, it follows that direct magnetic separation can be applied to separate very fine sized particles. These structural differences explain previously observed dissimilarities from corrosion and metal release perspectives. 相似文献
97.
Oskar Rexfelt Lars Almefelt Daniel Zackrisson Teres Hallman Johan Malmqvist MariAnne Karlsson 《Research in Engineering Design》2011,22(3):153-171
This paper outlines the results of a project aiming to develop and apply methods for service co-creation with customers, focusing
on the early phases of service development. The project is collaboration between a manufacturing firm in the automotive industry,
one of their B2B-customers (a transportation firm), as well as a university, all in Sweden. The research team selected and
developed methods and work practices for problem analysis, idea generation, development and evaluation of services. Thus doing,
methodological influence was taken from the area of engineering design. The proposed approaches were applied in a service
development experiment mainly based on workshops. The experiment was followed up by an analysis of the resulting output, an
interview series, and an evaluation by peers in focus groups. The goal of this article is to answer the following research
questions: (1) What is the industrial applicability of co-creating services using a structured approach, e.g. what are the
benefits and challenges? (2) What do the different actors contribute with using this approach, and what possible factors influence
the nature and quality of the actors’ contributions? (3) Based on the answers to the questions above, what aspects should
be considered to support situated planning and execution of future service co-creation projects? A central conclusion is that
a structured approach is industrially applicable, but it is also evident that there is no completely universal recipe for
service innovation. Addressing these insights, the paper also contributes with guidelines to support the situation-adapted
set-up of future service co-creation projects. 相似文献
98.
99.
J Kartus S Stener R Nilsén U Nilsson BI Eriksson J Karlsson 《Canadian Metallurgical Quarterly》1998,8(6):449-455
Dairy calves under 14 days of age with naturally occurring, uncomplicated diarrhea were treated for 3 days with a hypertonic oral electrolyte solution with (n = 15) or without (n = 12) psyllium. Clinical response and clinical pathology data were compared between the 2 groups. Glucose absorption was evaluated on days 1 and 3 by measurement of plasma glucose and lactate and serum insulin concentrations for 4 hours after formula administration. On day 1, glucose, lactate, and insulin concentrations were lower in psyllium-fed calves than in control calves, with significant differences noted in glucose and lactate concentrations at several time points (P < 0.05). Plasma lactate concentrations were higher at several times in both treatment groups on day 3 than on day 1 (P < 0.05). Fecal consistency was markedly different in psyllium-fed calves as compared with control calves within 24 hours of psyllium supplementation. Fecal percent dry matter content was lower in psyllium-fed calves than in control calves at least once a day during supplementation and on day 3 compared with day 0 in the psyllium-fed calves (P < 0.05). There were no significant differences in clinical performance scores, hydration status, arterial blood gas, serum anion gap, electrolyte, or total CO2 concentrations. Addition of psyllium to an oral electrolyte solution resulted in immediate alterations in glucose absorption without impairing rehydration in diarrheic calves, but differences were transient and did not affect clinical outcome. 相似文献
100.
T Jensen EM Aliouat B Lundgren OP Settnes A Karlsson C Dahlgren E Dei-Cas N Obel 《Canadian Metallurgical Quarterly》1998,45(5):544-547
The production of free radicals in human neutrophils was studied in both Pneumocystis carinii derived from cultures of L2 rat lung epithelial-like cells and Pneumocystis carinii purified from human lung. Using the cytochrome C technique, which selectively measured extracellular superoxide generation, hardly any free radical production was observed after stimulation with cultured rat-derived P. carinii. A chemiluminescence technique, which separately measured intra- and extracellular free radical production, was subsequently employed to differentiate the free radical generation. It was established that 1) P. carinii stimulated intra- but not extracellular free radical production in human neutrophils, 2) opsonized cultured rat-derived P. carinii stimulated human neutrophils to a strong intracellular response of superoxide production, and 3) opsonized P. carinii, purified from human lung also stimulated human neutrophils to produce intracellular free radicals. 相似文献