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| 3. |
- Almgren, Gunnar
(författare)
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Luleå-högskolan och dess bergteknik
- 1977
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Ingår i: JkA: Jernkontorets Annaler. - 0280-4239. ; :3, s. 58-60
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Bengtsson, B., et al.
(författare)
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Quantitative STEM microanalysis
- 1978
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Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 7:2, s. 57-59
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Tidskriftsartikel (refereegranskat)
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| 5. |
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| 6. |
- Bengtsson, Lars
(författare)
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Snowmelt estimated from energy budget studies
- 1976
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Ingår i: Nordic Hydrology. - : IWA Publishing. - 0029-1277 .- 1996-9694. ; 7:1, s. 3-18
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Tidskriftsartikel (refereegranskat)abstract
- The snowmelt at a point is estimated through a simplified energy budget. From the energy equation a degree-day method is derived. The rate of snowmelt is found as a constant multiplied by the temperature excess over an equilibrium temperature which depends on solar radiation.The snowmelt events in Kiruna (3 years) and Luleå (4 years) are analysed utilizing energy balance computations and the degree-day method. First observed and calculated day when the ground was free of snow is for all seven years in good agreement. The rate of snowmelt calculated by the proposed degree-day method is almost identical to the rate found from energy balance computations. Snowmelt rates estimated by a simple degree-day method using a constant equilibrium temperature are too fast in the beginning and too slow at the end of the melting season.
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| 7. |
- Bengtsson, Lars
(författare)
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Snösmältning i tätort
- 1979
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Ingår i: Väg- och Vattenbyggaren. - 0042-2177. ; :11/12, s. 38-42
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 8. |
- Bengtsson, Lars
(författare)
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Wind Induced Circulation in Lakes
- 1978
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Ingår i: Nordic Hydrology. - : IWA Publishing. - 0029-1277 .- 1996-9694. ; 9:2, s. 75-94
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Tidskriftsartikel (refereegranskat)abstract
- In most lakes the wind is the most important flow generating mechanism. In this paper the problem of wind generated circulation - directly wind induced currents and seiches - in small lakes is reviewed. Many field observations are presented and discussed. In the thermocline and the hypolimnion forced seiche currents are shown to dominate the directly induced wind currents. Different kind of non-convective mathematical lake models are discussed and applied to different small lakes. Comparisons of observed and calculated currents show that lake models can be used to reproduce the currents of the upper 3–4 metres in a lake. The interaction between large-scale flow and turbulent flow is yet unknown, and therefore it is not possible to explain the physical current pattern and density anomalies at greater depth. In respect to the limited knowledge on turbulent processes in lakes, it is acceptable to apply a quadric relationship between wind stress and wind speed with a drag coefficient of about 1.0.10−3.
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| 9. |
- Bengtsson, L.
(författare)
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Wind Induced Circulation In Lakes
- 1978
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Ingår i: Nordic Hydrology. - 0029-1277 .- 1996-9694. ; 9:2, s. 75-94
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Tidskriftsartikel (refereegranskat)
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| 10. |
- Bergman, Gunnar, et al.
(författare)
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Antiplasticization and transition to marked nonlinear viscoelasticity in poly(vinyl chloride)/acrylonitrile–butadiene copolymer blends
- 1977
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Ingår i: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 21:11, s. 2953-2961
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Tidskriftsartikel (refereegranskat)abstract
- A series of PVC/NBR blends with varying acrylonitrile (AN) content in the NBR has been studied in uniaxial tension creep tests. The tests have been carried out at 21.5 ± 0.5°C covering creep times from 10 to 1000 sec. NBR with low AN content, having poor compatibility with PVC, gives the blends with higher compliance and increased time dependence of the compliance. A higher AN content in the NBR gives the blends with the opposite properties when the NBR is added in small amounts. NBR with 40 wt‐% AN is found to act as an antiplasticizer giving minimal creep compliance when 7 wt‐% NBR is added. The antiplasticization reveals a considerably increased stress level at which the transition from approximatively linear to marked nonlinear viscoelasticity occurs and a decreased stress dependence of the creep compliance in the nonlinear viscoelastic range. Since the antiplasticization is also associated with a suppression of the β‐transition mechanism, the results provide a demonstration of the importance of β‐mechanism in the stress activated processes responsible for the appearance of nonlinear viscoelasticity in solid polymers.
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