| 1. |
|
|
| 2. |
- Almgren, Gunnar
(författare)
-
Education in mining and rock excavation in Sweden
- 1984
-
Ingår i: The 12th Congress of World Mining Congress, New Delhi, November 19-23, 1984. - Calcutta : American Institute of Chemical Engineers.
-
Konferensbidrag (refereegranskat)abstract
- Education in Mining and Rock Excavation in Sweden can be subdivided into higher education, upper secondary school education and in-service training. Higher education is provided at the University of Lulea and leads to a Masters degree and to a Licentiate or Doctor of Engineering degree in mining. The higher education curriculum was replanned in connection with the move to Lulea in 1972 from the Royal Institute of Technology in Stockholm to involve higher specialization and to cover both the mining and the underground construction sectors. The upper secondary school education is given at the College of Mining and Metallurgy in Filipstad and leads to a secondary-school engineering degree. In-service training courses are given for working professionals by the Division of Advanced Vocational Training in Lulea and by equipment suppliers. Vocational training is pursued at some upper secondary schools in cooperation with the mining companies.
|
|
| 3. |
- Andersson, L-E, et al.
(författare)
-
Some fundamental transmission properties of impedance transitions
- 1984
-
Ingår i: Wave motion. - : Elsevier BV. - 0165-2125 .- 1878-433X. ; 6:4, s. 389-406
-
Tidskriftsartikel (refereegranskat)abstract
- Reflection and transmission of waves by impedance transitions from a constant input to a constant output characteristic impedence are considered. Several fundamental properties are explored, primarily for impedance transitions with piece-wise constant characteristic impedance in an arbitrary number N of intervals of equal length. For example, the following properties are shown: (i) The relative momentum transmission depends only on the ratio of output to input characteristic impedance. (ii) For a given impedance transition there are at most, and generally exactly, 2N different transitions, including the original one, with identical transmission properties. (iii) For monotoneous impedance transitions the efficiency of energy transmission is minimized by one with an abrupt change in characteristic impedance. (iv) There exists an optimal impedance transition, with a certain antisymmetry, which maximizes the efficiency of energy transmission for a given incident wave of finite duration and energy. Several of the results can be extended to more general classes of impedence transitions. Simple illustrative examples are given.
|
|
| 4. |
- Aronsson, Gunnar
(författare)
-
On certain singular solutions of the partial differential equation ux2uxx+2uxuyuxy+uy2uyy=0
- 1984
-
Ingår i: Manuscripta mathematica. - 0025-2611 .- 1432-1785. ; 47:1-3, s. 133-151
-
Tidskriftsartikel (refereegranskat)abstract
- The partial differential equation treated here is the formal limit of the p-harmonic equation in R2, for p →∞. Questions related to the smoothness of solutions and the possible existence of stationary points are central for the theory. The singular solutions constructed here bring new light on these questions.
|
|
| 5. |
- Ashby, M.F., et al.
(författare)
-
The transformation hardening of steel surfaces by laser beams-I. Hypo-eutectoid steels
- 1984
-
Ingår i: Acta Metallurgica. - : Elsevier BV. - 0001-6160. ; 32:11, s. 1935-1948
-
Tidskriftsartikel (refereegranskat)abstract
- Surfaces can be treated with a scanning laser beam to modify their properties. The beam subjects the near-surface to a thermal cycle with an amplitude and shape which depends on the process variables: the beam size, energy, scan rate and on whether the laser is pulse or continuous, and the chemistry and metallurgy of the steel. Approximate solutions to the equations of heat flow are combined with kinetic models to predict the near-surface structure and hardness of plain carbon steels after laser treatment. The results are assembled into diagrams which show immediately the combination of process variables for a desired surface structure and the associated hardness profile
|
|
| 6. |
|
|
| 7. |
- Axsäter, Sven, et al.
(författare)
-
In-process safety stocks
- 1984
-
Ingår i: Proceedings of the 23rd IEEE Conference on Decision and Control, December 12-14, 1984, Las Vegas Hilton, Las Vegas, Nevada. - New York : IEEE Communications Society. ; , s. 839-842, s. 839-841
-
Konferensbidrag (refereegranskat)abstract
- This paper derives the optimal safety stock policy for the case of a continuous deterministic production process and Poisson demand for the end product. It is possible to keep in-process safety stocks as well as a safety stock of the end product. We show that the optimal solution can be derived recursively and illustrate the procedure with the aid of a numerical example.
|
|
| 8. |
- Bengtsson, B., et al.
(författare)
-
Laser hardening of steel
- 1984
-
Ingår i: Materials Research Society Symposia Proceedings. - Amsterdam : Elsevier. - 0444009019 ; , s. 789-793
-
Konferensbidrag (refereegranskat)
|
|
| 9. |
- Berglund, Kris, et al.
(författare)
-
Modeling of growth rate dispersion of citric acid monohydrate in continuous crystallizers
- 1984
-
Ingår i: AIChE Journal. - : Wiley. - 0001-1541 .- 1547-5905. ; 30:2, s. 280-287
-
Tidskriftsartikel (refereegranskat)abstract
- A mathematical model for prediction of the crystal size distribution from a continuous crystallizer is presented. The kinetic data used for the model were obtained from batch contact nucleation experiments with citric acid monohydrate. In these experiments, the distribution of growth rates as well as the initial size distribution were estimated. Results from the model indicate that the excess number of crystals usually present at small sizes in continuous crystallizers is due to growth rate dispersion (where crystals of the same size may have different growth rates) and not size dependent growth.
|
|
| 10. |
- Bergman, Bo, et al.
(författare)
-
The total time on test concept and its use in reliability theory
- 1984
-
Ingår i: Operations Research. - : Institute for Operations Research and the Management Sciences (INFORMS). - 0030-364X .- 1526-5463. ; 32:3, s. 596-606
-
Tidskriftsartikel (refereegranskat)abstract
- More than 30 years ago, Epstein and Sobel introduced the Total Time on Test (TTT-) concept. During the last 10 years different generalizations of this concept have been defined and studied, e.g. the TTT-transform and the TTT-plot; a basic paper was presented by Barlow and Campo in 1975. Many of these generalizations have proven to be very useful in different areas of reliability, both from a theoretical and a practical point of view. The purpose of this expository paper is to present some of these generalizations and illustrate their value.
|
|
