| 1. |
- Ahmed, Istaq, 1972, et al.
(författare)
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Synthesis and structural characterization of perovskite type proton conducting BaZr1-xInxO3-delta (0.0 <= x <= 0.75)
- 2006
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Ingår i: Solid State Ionics. - : Elsevier BV. - 0167-2738 .- 1872-7689. ; 177:17-18, s. 1395-1403
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Tidskriftsartikel (refereegranskat)abstract
- Solid state sintering has been used to prepare the cubic perovskite structured compounds BaZr1-xInxO3-delta (0.0 <= x <= 0.75). Analysis of X-ray powder diffraction (XRPD) data reveals that the unit cell parameter, a, increases linearly with an increased Indium concentration. XRPD data was also used to demonstrate the completion of sample hydration, which was reached when the materials showed a set of single-phase Bragg-peaks. Dynamic thermogravimetric analysis (TGA) data showed that approx. 89% of the total number of available oxygen vacancies can be filled in BaZr1-xInxO3-delta for x=0.50, and that the maximum water uptake occurs below 300 degrees C. Rietveld analysis of the room temperature neutron powder diffraction (NPD) data confirmed the average cubic symmetry (space group Pm-3m), and an expansion of the unit cell parameter after the hydration reaction. The strong O-H stretch band, 2500-3500 cm(-1), in the infrared absorbance spectrum clearly manifests the presence of protons in the hydrated material. Proton conductivity of hydrated BaZr1-xInxO3-delta, x=0.75 was investigated during heating and cooling cycles under dry argon atmosphere. The total conductivity during the heating cycle was nearly two orders of magnitude greater than that of cooling cycle at 300 degrees C, whilst these values were similar at higher temperatures i.e. T > 600 degrees C.
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| 2. |
- Andersson, Roy, et al.
(författare)
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Similarities and differences between TQM, six sigma and lean
- 2006
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Ingår i: TQM Magazine. - : Emerald. - 0954-478X .- 1758-6887. ; 18:3, s. 282-296
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Purpose – During the last decades, different quality management concepts, including total quality management (TQM), six sigma and lean, have been applied by many different organisations. Although much important work has been documented regarding TQM, six sigma and lean, a number of questions remain concerning the applicability of these concepts in various organisations and contexts. Hence, the purpose of this paper is to describe the similarities and differences between the concepts, including an evaluation and criticism of each concept.Design/methodology/approach – Within a case study, a literature review and face‐to‐face interviews in typical TQM, six sigma and lean organisations have been carried out.Findings – While TQM, six sigma and lean have many similarities, especially concerning origin, methodologies, tools and effects, they differ in some areas, in particular concerning the main theory, approach and the main criticism. The lean concept is slightly different from TQM and six sigma. However, there is a lot to gain if organisations are able to combine these three concepts, as they are complementary. Six sigma and lean are excellent road‐maps, which could be used one by one or combined, together with the values in TQM.Originality/value – The paper provides guidance to organisations regarding the applicability and properties of quality concepts. Organisations need to work continuously with customer‐orientated activities in order to survive; irrespective of how these activities are labelled. The paper will also serve as a basis for further research in this area, focusing on practical experience of these concepts.
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| 3. |
- Eriksson, John, 1973, et al.
(författare)
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A Mass-Transport Model for Drying Wood under Isothermal Conditions
- 2005
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Ingår i: 9th international IUFRO wood drying conference, Nanjing, China, August 21-26, 2005. ; 1:1, s. 51-56
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Mass transport in wood during drying is often described in terms of different periods. Depending on the current moisture content (MC) and the structure of the wood, the driving forces behind the mass transport are essentially different. Above a certain level of MC, the fibres are partially saturated and the transport of liquid (free) water occurs mainly as a consequence of capillary action. On the other hand, below the fibre saturation point, bound water within the cell walls is conveyed by diffusion, and water vapour in the lumen moves under influence of pressures. In this contribution, a unified model is presented that takes into account the transport of the different water phases. Simulation of the drying of a Norway spruce sample from about 135% to 7% MC is carried out using the finite element method (FEM). The resulting mean MC is compared with experimental observations obtained from X-ray Computed Tomography showing reasonable agreement. Possible simplifications in the model are briefly discussed as well as some aspects of the numerical implementation.
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| 4. |
- Eriksson, John, 1973, et al.
(författare)
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A Mass Transport Model for Drying Wood under Isothermal Conditions
- 2007
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Ingår i: Drying Technology. - : Informa UK Limited. - 1532-2300 .- 0737-3937. ; 25:3, s. 433-439
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Tidskriftsartikel (refereegranskat)abstract
- Mass transport in wood during drying can have different mechanisms at different periods of drying. Depending on the current moisture content (MC) and the structure of the wood, the driving forces for the mass transport are essentially different. Above the fiber saturation point (FSP), the lumens are partially saturated and the transport of liquid (free) water occurs as a consequence of capillary action. On the other hand, below the FSP, bound water within the cell walls is conveyed by diffusion, and water vapor in the lumens moves under influence of pressures gradient. Based on these considerations, a unified model is presented that takes into account the transport of the different moisture phases. Simulation of the drying of a Norway spruce sample at 50°C from about 135 to 7% MC is carried out using the finite element method (FEM). Comparison between the simulated average MC and the experimental observations obtained from X-ray computed tomography (CT) shows reasonable agreement. Possible simplifications in the model are briefly discussed as well as some aspects of the numerical implementation. Finally, the influence of absolute permeability on the average MC is studied.
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