| 61. |
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| 62. |
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| 63. |
- Larsson, Kenneth, et al.
(författare)
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Methanolysis of galacturonic acid
- 1974
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Ingår i: Carbohydrate Research. ; 34, s. 323-329
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Tidskriftsartikel (refereegranskat)abstract
- Dimethyl acetals of galacturono-6,3-lactone and methyl galacturonate are formed during methanolysis of galacturonic acid. The products of methanolysis were studied by ion exchange and gas chromatography. Trimethylsilyl (TMS) derivatives were used in gas chromatography. Structure determinations were made from mass spectra of the TMS derivatives. The course of methanolysis was investigated by means of a gas chromatographic study of the composition of the reaction mixture as a function of time.
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| 64. |
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| 65. |
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| 66. |
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| 67. |
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| 68. |
- Leckner, Bo G, 1936
(författare)
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Heat transfer in the entrance region with fully develped turbulent flow between parallel plates
- 1972
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Ingår i: International Journal of Heat and Mass Transfer. - 0017-9310. ; 15, s. 35-42
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Tidskriftsartikel (refereegranskat)abstract
- An analysis is made of local heat transfer in a thermal entrance region with a fully developedturbulent velocity profile for various Reynolds and Prandtl numbers. Difference methods are used tosolve the energy equation. The velocity and eddy diffusivities are described by semi-empirical relationships.The geometrical picture is simple: flow between parallel plates, one of which is thermally insulated, theother transmits a known heat flux. Certain comparisons with calculations on laminar flow are made as acheck on the reliability of the numerical method. This also provides an estimate of the influence of turbulencein the various cases and gives a possibility of judging the validity of approximations. Finally a comparisonwith available empirical expressions for fully developed heat transfer is shown
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| 69. |
- Leckner, Bo G, 1936
(författare)
-
Radiation from flames and gases in a cold wall combustion chamber
- 1970
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Ingår i: International Journal of Heat and Mass Transfer. - 0017-9310. ; 13:1, s. 185-197
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Tidskriftsartikel (refereegranskat)abstract
- The calculation of heat transfer in furnaces is usually based on coarse approximations of temperatureand emissivity in the combustion chamber. This paper suggests a method suitable for machinecomputation of the heat transfer from flames and gases to the walls of a furnace. A theoretical derivationof the basic equation is made and the simplifications necessary for execution of the calculation in acceptabletime are discussed The patterns of temperature and flame. emissivity are described by means of simplefunctions, a mathematical model. Experiments were carried out in an experimental furnace of simplegeometry using one oil-burner in order to check the accuracy of the theoretical assumptions. Mcasurementsof flame and gas temperature, flame emissivity, wall heat flux and exterior measurements necessaryfor the heat balance of the furnace were done. The measurements of temperature and emissivity define themathematical model.The heat transfer from flame and gases (including the contribution due to reflexion, non-cold surfacesand convection) was calculated at four different loads of the furnace and compared with the heat fluxmeasurements. The difference between measured and calculated heat flux, due to errors of measurementsand calculations, was less than about 15 per cent of the total heat flux.
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| 70. |
- Leckner, Bo G, 1936
(författare)
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Radiative heat transfer calculations in real gases
- 1974
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Ingår i: Waerme-Stoffuebertrag Thermo-Fluid Dyn. - 0042-9929 .- 1432-1181. ; 70:4, s. 236-247
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Tidskriftsartikel (refereegranskat)abstract
- A general formulation for radiative heat transfercalculations is presented, based on integrated quantities such as total emissivities and absorptivities. The procedure is intended particularly for combustion chamber applications of varEing degree of complexity, the radiative active medium consisting of gases such as H20 and CO2 and of soot. First, some preliminary calculations are given for the often treated radiative equilibrium cases of plane parallel plates and infinite concentric cylinders. Then an example of a combustion chamber calculation is studied where the radiative heat transfer calculation is included in a system of partial differential equations describing momentum, hear and mass transfer with combustion.
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