| 1. |
- Zhao, Ming, et al.
(författare)
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Strain-symmetrized Si/SiGe multi-quantum well structures grown by molecular beam epitaxy for intersubband engineering
- 2006
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Ingår i: Journal of luminescence. - : Elsevier BV. - 0022-2313. ; 121:2, s. 403-408
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Tidskriftsartikel (refereegranskat)abstract
- Three strain-symmetrized Si/SiGe multi-quantum well structures, designed for probing the carrier lifetime of intrawell intersubband transitions between heavy hole 1 (HH1) and light hole 1 (LH1) states with transition energies below the optical phonon energy, were grown by molecular beam epitaxy at low temperature on fully relaxed SiGe virtual substrates. The grown structures were characterized by using various experimental techniques, showing a high crystalline quality and very precise growth control. The lifetime of the LH1 excited state was determined directly with pump-probe spectroscopy. The measurements indicated an increase of the lifetime by a factor of 2 due to the increasingly unconfined LH1 state, which agreed very well with the design. It also showed a very long lifetime of several hundred picoseconds for the holes excited out of the well to transit back to the well through a diagonal process.
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| 2. |
- Asayesh, Amir, et al.
(författare)
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Spleen versus pancreas : strict control of organ interrelationship revealed by analyses of Bapx1-/- mice.
- 2006
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Ingår i: Genes & Development. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 20:16, s. 2208-2213
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Tidskriftsartikel (refereegranskat)abstract
- During early stages of pancreatic development, the mesenchyme that contributes to the spleen overlies the dorsal pancreatic endoderm. Here, we show that interactions between splenic mesenchyme and pancreas proceed via a highly orchestrated morphogenetic program. Disruption of morphogenesis, as occurs in the Bapx1(Nkx3.2)−/− embryo, results in transformation of these tissues into well-organized, ectopic gut-like structures. Bapx1 plays a crucial organizing role effecting position and separation of the spleen and pancreas to prevent this metaplastic transformation. Similar transformations occur in organ cultures employing wild-type pancreatic endoderm and spleen mesenchyme, revealing the developmental plasticity of the pancreas and that precise spatial and temporal control of tissue interactions are required for development of both organs.
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| 3. |
- Eriksson, Kent, et al.
(författare)
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Knowledge of inter-customer relations as a source of value creation and commitment in financial service firm's intermediation
- 2007
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Ingår i: Service Industries Journal. - : Informa UK Limited. - 0264-2069 .- 1743-9507. ; 27:5, s. 563-582
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Tidskriftsartikel (refereegranskat)abstract
- This paper develops a knowledge perspective on value creation in organisations that employ mediating technology to facilitate inter-customer relations. Mediators, individually and collectively, build networks of customers between whom linking can take place, and they provide services that facilitate inter-customer exchanges. Earlier research has shown the importance of size and standardisation in mediation. A different stream of research has shown that contextual knowledge is important for problem solving and innovation in organisations. Combining theories of mediating technology and situated problem solving, the paper posits that inter-customer relations constitute the fundamental context for value creation of firms using the mediating technology. LISREL is used to test relationship-level, cross-sectional hypotheses that link knowledge of inter-customer relationships, added value, and customer commitment to bank services for small firms. This work extends Thompson's work on mediating technology with implications for organisation action by demonstrating that mediators' knowledge of inter- customer relationships is an important resource in intermediation. Three contributions are made to strategic management and organisation theory. First, the paper provides a deeper understanding of the relationship between knowledge and committed customers. Second, fundamental resources are developed for firms using mediating technology. Finally, the use of the situated knowledge concept is extended to inter-customer relations, thus explaining performance beyond the contexts to which the concept has previously been applied. The findings have implications for segmentation practices, organisation domain decisions and the corresponding organisational
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| 4. |
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| 5. |
- Olsson, Lars E, et al.
(författare)
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(1)H and hyperpolarized (3)He MR imaging of mouse with LPS-induced inflammation.
- 2009
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Ingår i: Journal of magnetic resonance imaging : JMRI. - : Wiley. - 1053-1807 .- 1522-2586. ; 29:4, s. 977-81
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To evaluate the lipopolysaccharide (LPS) model of chronic obstructive pulmonary disease (COPD) in mouse with (1)H and hyperpolarized (HP) (3)He MR imaging. MATERIALS AND METHODS: Axial slices of the lung volume were acquired with HP (3)He and (1)H MRI at 4, 24, and 48 h after LPS exposure. A quantitative ventilation index was calculated from two HP (3)He acquisitions. A bronchoalveolar lavage (BAL) for a cell count was performed following magnetic resonance imaging (MRI). RESULTS: The LPS exposure resulted in a significant increase of cells in BAL, with maximum at 48 h. Lesions on (3)He images were characterized by ventilation defects, whereas lesions on (1)H images were hyperintense and were attributed to edema. The number of lesions was at maximum at 48 h. At this time point, and for both (3)He and (1)H MRI, the volume of the lesions was significantly higher for LPS-exposed mice compared to controls. At 4, 24, and 48 h the ventilation index from the (3)He data was significantly smaller for the LPS-exposed animals compared to controls. CONCLUSION: The time point 48 h after LPS exposure was advantageous for MRI evaluation. Functional read-out with (3)He MRI seems to be more sensitive than conventional (1)H MRI.
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| 6. |
- Zargar, S. T., et al.
(författare)
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RRNA : Reliable soft real-time network aware grid scheduling algorithm using round trip time
- 2009
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Ingår i: Spring Simulation Multiconference 2009 - Co-located with the 2009 SISO Spring Simulation Interoperability Workshop. - : Association for Computing Machinery (ACM).
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Konferensbidrag (refereegranskat)abstract
- Assigning jobs to optimum resources in a grid environment is the main aim of a grid scheduler. Communication cost has always been an important issue in grid environments. Proposing new scheduling algorithms to consider this cost accurately and allocate jobs to an optimum resource efficiently has always been of great importance. In this paper we have proposed a grid scheduling algorithm that is aware of the costs for different network paths.We have also considered soft realtime characteristics of jobs in our proposed algorithm. We have simulated and compared our algorithm with some key scheduling algorithms such as Least Load First (LLF), Random, and First Come First Served (FCFS) in Gridsim by considering soft real-time jobs. Results show the superiority of our scheduling algorithm due to its ability to predict network cost and to satisfy the demands of soft real-time tasks.
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| 7. |
- Zhao, Ming, et al.
(författare)
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Molecular beam epitaxy growth of Si/SiGe bound-to-continuum quantum cascade structures for THz emission
- 2008
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 517:1, s. 34-37
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Tidskriftsartikel (refereegranskat)abstract
- A Si/SiGe bound-to-continuum quantum cascade design for THz emission was grown using solid-source molecular beam epitaxy on Si0.8Ge0.2 virtual substrates. The growth parameters were carefully studied and several samples with different boron doping concentrations were grown at optimized conditions. Extensive material characterizations revealed a high crystalline quality of the grown structures with an excellent growth control. Layer undulations resulting from a nonuniform strain field, introduced by high doping concentration, were observed. The device characterizations suggested that a modification on the design was needed in order to enhance the THz emission.
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