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| 42. |
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| 43. |
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| 44. |
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| 45. |
- Norinder, Harald
(författare)
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Cathode-ray oscillographic investigations on atmospherics
- 1936
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Ingår i: Proceedings of the Institute of Radio Engineers. - 0731-5996. ; 24:2, s. 287-304
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Tidskriftsartikel (refereegranskat)abstract
- An analysis of the true nature of the wave forms of atmospherics, when they show rapid time variations, can easily be obtained by using cathode-ray oscillographs with very high speed recording. The author describes the arrangement that he has used for recording and analyzing atmospherics, with his relay construction of high voltage cathode-ray oscillographs. These instruments were connected through amplifiers to horizontal aerials having different heights above the ground. A passing atmospheric produced voltage changes across a resistor inserted in the antenna system, which, provided that special precautions were taken, gave the dE/dt variations of the field E. By applying an integration procedure to the records, it was possible to obtain the true field curves E(t) of the corresponding atmospherics. These observations were made at field stations located in the vicinity of the Institute of High Tension Research, University of Uppsala, Sweden. The results of observations made between February and August, 1934, are dealt with in this paper. About 7500 atmospherics were recorded, of which 600 were selected as typical, and have been integrated. The total duration times of individual atmospherics that were most frequently observed lay between 100 and 150 microseconds. When periodic or quasi-periodic variations were observed, about sixty per cent of such atmospherics showed a periodicity of between five and ten kilocycles per second. The atmospherics frequently occurred in groups composed of a number of separate and individual field variations. The time duration of about seventy per cent of such groups was within 5 × 10-2seconds.
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| 46. |
- Norinder, Harald
(författare)
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Lightning currents and their variations
- 1935
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Ingår i: Journal of the Franklin Institute. - 0016-0032 .- 1879-2693. ; 220:1, s. 69-92
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Tidskriftsartikel (refereegranskat)
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| 47. |
- Norinder, Harald
(författare)
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The relation between lighting discharges and atmospherics in radio receiving
- 1936
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Ingår i: Journal of the Franklin Institute. - 0016-0032 .- 1879-2693. ; 221:5, s. 585-611
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Tidskriftsartikel (refereegranskat)abstract
- In order to examine the relations between lightning discharges and atmospherics cathode ray oscillographs were applied to record the variation forms of atmospherics. By simultaneous observations of atmospherics, by the aid of the loud speakers of radio receiving sets and corresponding records by cathode ray oscillographs the existence of two characteristic variation forms of atmospherics in connection with thunderstorms were obtained, (a) “the clicks”-singular discharges of a comparatively short duration (up to some hundred microseconds) and caused by shorter local sparks, (b) “the grinders” whistling or hissing perturbation forms in the loud speakers. The corresponding oscillograms resulted in complicated variation forms of the same type as the Author had observed to be usual in ordinary lightning discharges. The relation to lightning was further investigated in an indirect manner. By cathode ray oscillographic records atmospherics of ordinary types with their centres of origin at greater distances from the locality of observations were examined. These atmospherics showed in most cases very characteristic variation forms with more or less pronounced and superimposed periodic or quasiperiodic variation. The main problem was how to explain the generation of these variation forms from known discharges as they were observed at the most probable centres of emission—e.g. lightning paths. For that purpose the transmission equation for radio waves was applied on such discharge variation forms which had been observed to be usual in partial lightning discharges. From the calculation it was concluded that atmospherics with typical variations could be derived from lightning discharges with known and uncomplicated variation forms fixed by cathode ray oscillographic recording. The sometimes apparently complicated variation forms of atmospherics of the short variation type were thus in the most cases found to be a secondary effect caused by gradual deformation during transmission.
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| 48. |
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| 49. |
- Pedersen, Kai O.
(författare)
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Sedimentation equilibrium measurements with low molecular substances in the ultra-centrifuge
- 1935
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 135, s. 304-305
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Tidskriftsartikel (refereegranskat)abstract
- The calculated molecular weights agreed fairly well with the known values for these substances except in the cases of the substance with the lowest molecular weight, CsCl, where the difference in concentration was very small. Quite recently, Prof. Svedberg has greatly improved his ultra-centrifuge (see Svedberg, loc.
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