| 11. |
- Olsson, Eric, et al.
(författare)
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The frail elderly, family network and public home help services : a pilot study of the parties' perception of the help and their reciprocal relationships
- 2001
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Ingår i: Working paper-serien. - 9189604067 ; 2001:2
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The family with the elderly and the home help workers’ team constitute two organisations, which meet in the care work. In this context the family is extended and often constitute not only members from the nuclear family but also other members of the network of relatives, whom take part in the care of the elderly. The extended family may in some cases include four generations (Finch & Mason, 1993). Home-help for elderly people have expanded in Sweden during the period 1960 - 1980. This was due partly upon the prevailing ideology that it is important for frail elderly to stay in their own homes. Due to this expansion the local communities have developed their public home-care organisations. Different kinds of autonomous group organisation predominate (Olsson et al, 1995). Small work groups take responsibility for home help service in local areas. Home-helpers organise their job themselves, exchange experiences and give each other emotional support. In Sweden both home care and institutional care of the elderly has decreased during the 1980th and 1990th in spite of the fact that the proportion elderly over 80 years (4,5 % of the total population) has increased 60 % since 1980. Twenty-two per cent of the women and 16 % of the men over 80 were cared for in their own home 1996. This development is said to have caused relatives to care for their frail elderly in the homes side by side by the home help services in an increasing degree (Johansson, 1991; Szebehely, 1998). Public care and service has an important impact on the interaction pattern between family members (Hendriksen, 1989; Johansson, 1999; Bass m fl, 1999). Home care may serve as an intervention that influences the health, well-being and life quality of the elderly and other family members. This intervention may have positive as well as negative effects. Problems and conflicts may arise in the interaction between the family members and between the family and the public help services (see McGoldrick & Gerson, 1989). We need more knowledge about these processes. In a research project1 the family and the home help services are studied as two organisations, which interact in the care of the elderly. We start with the hypothesis that the relation between the parties will have an impact on the character and quality of the care. We also think that the quality of the interaction will have an impact on the health and wellbeing of the elderly (see Olsson, 1991, 1998; Olsson & Ingvad, 1999).
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| 12. |
- Olsson, Jan-Ola, et al.
(författare)
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A Turbocharged Dual-Fuel HCCI Engine
- 2001
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Ingår i: SAE Special Publications. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0099-5908. ; 2001:1627
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Konferensbidrag (refereegranskat)abstract
- A 6-cylinder truck engine is modified for turbocharged dual-fuel Homogeneous Charge Compression Ignition (HCCI) engine operation. Two different fuels, ethanol and n-heptane, are used to control the ignition timing. The objective of this study is to demonstrate high load operation of a full-size HCCI engine and to discuss some of the typical constraints associated with HCCI operation. This study proves the possibility to achieve high loads, up to 16 bar Brake Mean Effective Pressure (BMEP), and ultra-low NOdx emissions, using turbo charging and dual fuel. Although the system shows great potential, it is obvious that the lack of inlet air pre heating is a drawback at low loads, where combustion efficiency suffers. At high loads, the low exhaust temperature provides little energy for turbocharging, thus causing pump losses higher than for a comparable diesel engine. Design of turbocharger therefore, is a key issue in order to achieve high loads in combination with high efficiency. In spite of these limitations, brake thermal efficiencies and power rating close to those of the original diesel engine are achieved with significant reduction in NOdx emissions. The maximum efficiency is 41.2%, which is slightly lower than for the original diesel engine.
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| 13. |
- Olsson, Jan-Ola, et al.
(författare)
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Closed-Loop Control of an HCCI Engine
- 2001
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Ingår i: SAE Transactions, Journal of Engines. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0096-736X. ; 110:3, s. 1076-1085
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a strategy for closed-loop control of a multi-cylinder turbocharged Homogeneous Charge Compression Ignition (HCCI) engine. A dual fuel port injection system allows control of combustion timing and load individually for each cylinder. The two fuels used are isooctane and n-heptane, which provides a wide range of autoignition properties. Cylinder pressure sensors provide feedback and information regarding combustion. The angle of 50% heat release is calculated in real time for each cycle and used for timing feedback. Inlet air preheating is used at low loads to maintain a high combustion efficiency.
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| 14. |
- Olsson, Louise, 1974, et al.
(författare)
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A Kinetic Study of NO Oxidation and NOx Storage on Pt/Al2O3 and Pt/BaO/Al2O3
- 2001
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Ingår i: Journal of Physical Chemistry B Materials. - : American Chemical Society (ACS). - 1089-5647 .- 1520-6106 .- 1520-5207. ; 105:29, s. 6895-6906
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Tidskriftsartikel (refereegranskat)abstract
- Modeling and flow reactor experiments were used to study the kinetics of NO, storage/release on a Pt/BaO/Al2O3 model catalyst. The mechanism for this concept can be divided into four steps: (i) NO to NO2 oxidation on Pt, (ii) NO2 storage on BaO, (iii) NO, release, and (iv) NO, reduction to N2. In this paper, we have focused on the first three steps. From the NO oxidation study on Pt/Al2O3 compared to Pt/BaO/Al2O3, we observed that the presence of BaO decreases the formation of NO2. To test the importance of this step for effective storage, experiments were performed with a Pt/Al2O3 catalyst placed before the Pt/BaO/Al2O3 catalyst. This resulted in increased NO, storage for the combined system compared to the Pt/BaO/Al2O3 case. To resolve the second and third steps, an experimental investigation of NOx storage/release on BaO/Al2O3 was performed using only NO2 and N2 in the gas feed. We propose a kinetic model, which first includes adsorption of NO2, which oxidizes the surface, followed by nitrate formation. Finally, NO3-BaO-NO2, i.e., Ba(NO3)2, is formed. By using the kinetic parameters from the NO oxidation on Pt/BaO/Al2O3 and the NO, storage on BaO/Al2O3, a kinetic model was constructed to describe NO, storage/release experiments on Pt/BaO/Al2O3. However, the rate for NO, release was increased when Pt was present, and the kinetic model could not accurately describe this phenomenon. Therefore, the mechanism was modified by including a reversible surface spillover step of NO2 between Pt sites and BaO sites. Further, experiments with NO2 exposure followed by a temperature ramp with NO/N2 showed that the desorption behaviors from the BaO/Al2O3 and Pt/BaO/Al2O3 were significantly different, which further supports the spillover mechanism. Finally, the models describing NO, storage on BaO/Al2O3 and on Pt/BaO/Al2O3 were successfully validated with independent experiments.
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| 15. |
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| 16. |
- Tunestål, Per, et al.
(författare)
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HCCI Operation of a Multi-Cylinder Engine
- 2001
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Ingår i: First Biennial Meeting of the Scandinavian-Nordic Section of the Combustion Institute. ; , s. 109-114
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A six-cylinder truck-size engine has been converted for Homogeneous Charge Compression Ignition (HCCI) operation. This work demonstrates that it is possible to run a multi-cylinder engine under HCCI operation. The ultra-low NOX characteristic of HCCI is also demonstrated. The sensitivity of combustion timing with respect to operating parameters is investigated, and a closed-loop control system is designed which utilizes the mixing ratio of two different fuels to control the timing of combustion. The performance of the control system is evaluated experimentally.
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| 17. |
- van Aarle, Ingrid, et al.
(författare)
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Microscopic detection of phosphatase activity of saprophytic and arbuscular mycorrhizal fungi using a fluorogenic substrate
- 2001
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Ingår i: Mycologia. - 0027-5514. ; 93:1, s. 17-24
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Tidskriftsartikel (refereegranskat)abstract
- The location and activity of saprophytic and arbuscular mycorrhizal (NM) fungal phosphatases have been investigated with a fluorogenic substrate (ELF) that forms a fluorescent crystalline precipitate at the site of phosphatase activity. This ELF substrate method was compared with other detection methods such as fast blue RR salt staining and p-nitrophenyl phosphate. The ELF substrate was successfully used to determine the location of phosphatase activity in AM fungal hyphae, and to visualize the active AM fungal colonization of roots. The substrate was taken up by fungal hyphae, when acid and alkaline buffers were used, and internal phosphatase activity was visualized. The release of both acid and alkaline phosphatases by a saprophytic fungus to an agar medium was demonstrated. ELF combined with an alkaline buffer led to specific staining of active fungal structures such as hyphae, arbuscules and young vesicles in AM-colonized roots. The results indicate that the ELF substrate is a sensitive indicator for fungal phosphatase activity and that it can be used to visualize hyphal phosphatase activity in both roots and external hyphae.
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