| Global and Temporal Distribution of Meteoric Smoke: A Two-Dimensional Simulation Study |
02 Feb 2008 |
16 pages |
| Authors:
L Megner; D E Siskind; M Rapp; J Gumbel; STOCKHOLM UNIV (SWEDEN)
|
 | Meteoric material entering Earth's atmosphere ablates in the mesosphere and is then expected to recondense into tiny so-called smoke particles. These particles are thought to be of great importance for middle atmosphere phenomena like noctilucent clouds, polar mesospheric summer echoes, metal layers, and heterogeneous chemistry. Commonly used one-dimensional (1-D) meteoric smoke profiles refer to average global conditions and yield of the order of a thousand nanometer sized particles per cubic ... |
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| Studies of Electron-Ion Interactions using the CRYRING Heavy-Ion Storage Ring Facility |
21 Sep 2007 |
2 pages |
| Authors:
Mats Larsson; STOCKHOLM UNIV (SWEDEN)
|
| This report results from a contract tasking Stockholm University as follows: The Grantee will investigate the measurements of branching ratios in recombination of polyatomic molecular ions. It is proposed to study not only the rates of dissociative recombination of ions important for plasma-enhanced combustion but also the neutral product distributions. Deuterated molecules and peak fitting procedures will be applied to enhance the resolution. The proposed measurements will add greatly to ... |
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| Rate Constants and Branching Ratios for the Dissociative Recombination of CO(2)+ |
10 JUN 2005 |
5 pages |
| Authors:
A. A. Viggiano; A. Ehlerding; F. Hellberg; R. D. Thomas; V. Zhaunerchyk; W. D. Geppert; H. Montaigne; M. Larsson; M. Kaminska; STOCKHOLM UNIV (SWEDEN)
|
| The overall rate constant of the dissociative recombination of CO(2)+ was first measured in 1967. Since then, the room-temperature rate was measured several times and the values obtained varied in the narrow range of (3.1-4.0) x 10(exp -7) cu cm s(exp -1). Recently, the rate was measured at the Aarhus storage ring in Denmark (ASTRID) and found to be larger, 6.5 x 10(exp -7) cu cm s(exp -1) at 300 ... |
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| Studies of Electron-Ion Interactions Using the CRYRING Heavy-Ion Storage Ring Facility |
JUN 2005 |
15 pages |
| Authors:
Mats Larsson; STOCKHOLM UNIV (SWEDEN)
|
| This report results from a contract tasking Stockholm University as follows: CRYRING, a synchrotron/heavy-ion storage ring facility, has proved to be a powerful tool for measurements of branching ratios in recombination of polyatomic molecular ions. However, there are important questions that still need to be addressed for organic ions such as: 1) Is there a mass limit at which fragmentation decreases or even vanishes and most or all of the ... |
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| Rate Constants and Branching Ratios for the Dissociative Recombination of C(3)D(7)+ and C(4)D(9)+ |
19 APR 2005 |
5 pages |
| Authors:
M. Larsson; A. Ehlerding; W. D. Geppert; F. Hellberg; S. Kalhori; F. Oesterdahl; G. Angelova; J. Semaniak; O. Novotny; STOCKHOLM UNIV (SWEDEN)
|
| The dissociative recombination of C(3)D(7)+ was measured in the ion storage ring CRYRING. The higher mass separation offered from the deuterated species provided more accurate branching ratios than the data obtained previously for C(3)H(7)+. We obtained rate constants of 2.3 + or - 0.4 x 10(exp -7) cu cm s(exp -1) for C(3)D(7)+ and 5.8 + or - 1.1 x 10(exp -7) for C(4)D(9)-. |
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| Studies of Electron-Ion Interactions Using the CRYRING Heavy-Ion Storage Ring Facility |
AUG 2002 |
12 pages |
| Authors:
Mats Larsson; STOCKHOLM UNIV (SWEDEN)
|
| This report results from a contract tasking Stockholm University as follows: CRYRING, a synchrotron/heavy-ion storage ring facility, has proved to be a powerful tool for measurements of branching ratios in recombination of polyatomic molecular ions. However, there are important questions that still need to be addressed for organic ions such as: 1)Is there a mass limit at which fragmentation decreases or even vanishes and most or all of the electron ... |
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| Nd2O3-Doped Sialons with ZrO2/ZnN Additions Formed by Sintering and Hot Isostatic Pressing. |
1994 |
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| Authors:
Thommy Ekstroem; Harald Herbertsson; Matthew James; Ian Fleck; STOCKHOLM UNIV (SWEDEN)
|
 | Beta-sialon and Nd2O3-doped alpha-sialon materials of varying composition were prepared by sintering at 1775 and 1825 C and by glass-encapsulated hot isostatic pressing at 1700 C. Composites were also prepared by adding 2-20 wt percent ZrO2 (3 mol percent Nd2O3) or 2-20 wt% ZrN to the beta-sialon and alpha-sialon matrix, respectively. Neodymium was found to be a fairly poor alpha-sialon stabilizer even within the alpha-phase solid solution area, and addition ... |
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| Sialon Ceramics Sintered With Yttria and Rare Earth Oxides |
93 |
|
| Authors:
Thommy Ekstroem; STOCKHOLM UNIV (SWEDEN)
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| Dense single-phase alpha-, beta- and O'-sialon ceramics without a glassy grain-boundary phase can be prepared at high temperatures and pressures, and these materials are well suited for high-temperature use, but they are usually brittle. Additional quantities of oxides of group IIIB metals in the periodic table are often added as sintering aids to achieve pressureless sintering and thereby to allow more complicated shapes to be manufactured directly and at lower ... |
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| Oxidation Kinetics of Si2N2O Ceramics |
93 |
|
| Authors:
Jeanette Persson; Per-Olov Kall; Mats Nygren; STOCKHOLM UNIV (SWEDEN)
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| Ceramics based on silicon nitride have been considered promising candidates for high temperature engineering applications due to their excellent refractory properties combined with high strength and good resistance to oxidation. It is well known, however, that the performance of ceramics varies considerably with chemical composition, for example with type and amount of intergranular phase. Especially the evaluation of the high temperature behavior of the ceramics under varying conditions is therefore ... |
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| Alumina Ceramics With Particle Inclusions |
93 |
|
| Authors:
Thommy Ekstroem; STOCKHOLM UNIV (SWEDEN)
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| Alumina composites have been prepared with particle inclusions of 0- 30 wt% titanium carbonitride and/or 0-3 wt% nickel, or nickel plus molybdenum metal. The metal was added in three different ways; as metal powder, as metal oxide, or as the intermetallic compound Ti2Ni. Pressureless sintering at 1750 C gave densities varying from 90% of theoretical density to full density. All materials were post-HIPed to full density at 1600 C before ... |
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| Hot Hardness Behavior of Yttrium Sialon Ceramics |
90 |
|
| Authors:
T. Ekstrom; J. Persson; STOCKHOLM UNIV (SWEDEN)
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| The hot hardness of polycrystalline single-phase alpha or beta sialon ceramics declines with increasing temperature, but the measured Vickers hardness at 1100C is still about 1550 and 1300 for the alpha-sialon and the low- substituted beta-sialon materials, respectively. The hardness of "composite" beta or alpha-beta-sialon containing a high volume fraction of glassy phase is lower at all temperatures and drops significantly above 900C. |
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| Sialon Ceramics Made with Mixtures of Y2O3-Nd2O3 as Sintering Aids |
90 |
|
| Authors:
Per-Olov Kaell; Thommy Ekstroem; STOCKHOLM UNIV (SWEDEN)
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| Pressureless sintering was used to prepare sialon ceramics at 1775 and 1825C, using mixtures of yttria and neodymia as sintering aids. It was found that at 1775C less dense materials were obtained, but fully dense materials could be produced by raising the sintering temperature to 1825C, even when pure neodymia was used. The hardness of the Nd-sialon ceramics was found to be slightly lower than for the corresponding Y-sialon ceramics, ... |
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| Pressureless Sintering of Y2O3-CeO2-Doped Sialons |
90 |
|
| Authors:
E. Soederlund; T. Ekstroem; STOCKHOLM UNIV (SWEDEN)
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| Various sialon materials have been prepared by pressureless sintering at 1775 and 1825 C using Y2O3 and/or CeO2 as sintering aids. Constant molar amounts of the oxide mixtures were added in the ratios Y203/CeO2: 100/0, 75/25, 50/50, 25/75, 0/100 corresponding to 6.0 and 9.25 wt% for the pure Y2O3 and pure CeO2, respectively. Only one of the compositional series reached full density at 1775 C with cerium replacing yttrium, whereas ... |
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| Pressureless Sintering of Sialon Ceramics with Mixed Y2O3-La2O3 Additions |
89 |
|
| Authors:
Thommy Ekstroem; Per-Olof Olsson; STOCKHOLM UNIV (SWEDEN)
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| Uber Theorie und Messung in der Psychologie (Theory and Measurement in Psychology), |
1966 |
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| Authors:
Gosta Ekman; Ingvar Lundberg; STOCKHOLM UNIV (SWEDEN)
|
| A handbook contains information on psychological theory and measurement methods. |
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| K(-) -ABSORPTION IN NUCLEI AND THE SIGMA HYPERON PION RESONANCE Y(0)*, |
1964 |
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| Authors:
A. Frisk; STOCKHOLM UNIV (SWEDEN)
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| The total energy distribution and the distribution of the invariant quantity M from 106 two prong stars are plotted with a charged sigma hyperon and a pion due to absorptions of negative K-mesons at rest in emulsion nuclei. It should be emphasized that the stars contain no other prongs than those due to the hyperon and the pion. The two distributions have about the same width and it is difficult ... |
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| PHASE ANALYSIS AND CRYSTAL STRUCTURE STUDIES ON BINARY ALLOYS OF ALUMINUM WITH TRANSITION METALS. |
NOV 1963 |
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| Authors:
Arne Magneli; Lars-Erik Edshammar; Tore Dagerhamn; STOCKHOLM UNIV (SWEDEN)
|
| In order to provide the necessary background for detailed crystal-chemistry studies in the field of binary aluminum - transition metal systems, extensive investigations have been carried out on the phase relations of a large number of such systems. The results of these studies are briefly summarized, as are also the results of crystal structure determinations of a few alumi num - transition metal phases. (Author) |
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| ON THE FORMULATION OF STATISTICAL METEOROLOGY, |
JUL 1963 |
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| Authors:
Walter Freiberger; Ulf Grenander; STOCKHOLM UNIV (SWEDEN)
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| LONG RANGE NAVIGATION IN ANIMALS, |
20 JUN 1963 |
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| Authors:
Carl Edelstam; STOCKHOLM UNIV (SWEDEN)
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| A laboratory study of the basis of visual acuity in man suggests that vision may not be a limiting factor in astronavigation among vertebrates. Field observations of pigeons navigating without the aid of celestial clues show that the birds shake their heads sideways at intervals. This confirms a prediction made by Ising on the assumption that birds use their semicircular canals for estimating latitude and directions from Coriolis force differences. ... |
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| THEORETICAL INVESTIGATIONS OF THE ELECTRONIC STRUCTURES AND STATES OF MOLECULES AND CRYSTALS. |
28 FEB 1963 |
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| Authors:
Inga FischerHjalmars; Stig Flodmark; STOCKHOLM UNIV (SWEDEN)
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| THEORETICAL INVESTIGATIONS OF THE ELECTRONIC STRUCTURES AND STATES OF MOLECULES AND CRYSTALS. |
30 NOV 1962 |
|
| Authors:
Inga Fischer-Hjalmars; Stig Flodmark; STOCKHOLM UNIV (SWEDEN)
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| HIGH ENERGY PHYSICS PROPERTIES OF ANTIPROTONS, K MESONS, HYPERONS, AND PIONS. |
31 OCT 1962 |
24 pages |
| Authors:
A.G. Ekspong; STOCKHOLM UNIV (SWEDEN)
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| INTERACTION OF 2 GEV NEGATIVE PI-MESONS WITH EMULSION NUCLEI, |
1962 |
|
| Authors:
B. E. RONNE; O. Danielsson; STOCKHOLM UNIV (SWEDEN)
|
| An investigation of 281 interactions of 2 GeV/c negative pions with emulsion nuclei is reported. The fraction of stars with charged secondary pions is 75=3 per cent, and the mean number per star of emitted charged pions is 1.21 =0.08. Only 2 K-mesons have been observed, which confirms other results that the production cross section of strange particles is low. Our results have been compared with the predictions from a ... |
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| THEORETICAL INVESTIGATION OF THE ELECTRONIC ENERGY BANDS FOR THE ZIRCONIUM-OXYGEN CRYSTAL. PART II. SYMMETRY-ADAPTED ORBITALS AND SECULAR ELEMENTS |
MAR 1961 |
|
| Authors:
Stig Flodmark; BJORN ROOS; STOCKHOLM UNIV (SWEDEN)
|
| Explicit formulae for the elements of the split secular equations which yield the electronic energy bands in the close-packed hexagonal Zr-O system are presented. The methods used to split the secular equations in the present report are based on the theoretical development outlined previously (AD-257 432). Certain singular idempotent projection matrices, labelled by the diagonal elements of the irreducible representations of the different little groups of the crystal symmetry group, ... |
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| A PSYCHOPHYSICAL STUDY OF CARTOGRAPHIC SYMBOLS |
18 FEB 1961 |
|
| Authors:
Gosta Ekman ; Ralf Lindman ; W. William Olsson; STOCKHOLM UNIV (SWEDEN)
|
| In two experiments the subjective volume of certain cartographic symbols was studied by the method of magnitude estimation. The stimulus material consisted of several sets of cubcl. illus. table, 12 refs. (Technical (Scientific) note no. 6) (Contract AF 61(052)300) (AFOSR-1247)Unclassified report DESCRIPTORS: *Visual perception, Perception, Measurement, Map reading. Open-ended Terms: Psychophysics. In two experiments the subjective volume of certain cartographic symbols ... |
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| THEORETICAL INVESTIGATION OF THE ELECTRONIC ENERGY BANDS FOR THE ZIRCONIUM-OXYGEN CRYSTAL. PART I. METHODS OF INVESTIGATION |
JAN 1961 |
|
| Authors:
Stig Flodmark; STOCKHOLM UNIV (SWEDEN)
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| CALCULATION AND TABULATION OF EXPANSION OEFFICIENTS FOR N SHELL MOLECULAR TWO-CENTER INTEGRALS BY MEANS OF THE ELECTRONIC COMPUTER BESK |
DEC 1960 |
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| Authors:
Stig Flodmark; STOCKHOLM UNIV (SWEDEN)
|
| The formulae for all the two-center integrals occurring in the MO-LCAO method with N shell Slater atomic orbitals is found from the tables of coefficients. The tables were computed by means of Besk according to a flow scheme. Using the corresponding program, which is working separately, it is possible to calculate the actual coefficients for integrals containing other shells as well. (Author) |
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| A NOTE ON THE SUBJECTIVE SPEED OF MANUAL WORK |
20 NOV 1960 |
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| Authors:
Gosta Ekman; ANDERS HERBERT; STOCKHOLM UNIV (SWEDEN)
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| A preliminary experiment is described, in which the speed of three manual activities was estimated by the method of magnitude estimation. Within the rather narrow stimulus range of 1/1.35 the subjective range was 1/1.86 for card dealing, 1/1.64 for shoveling gravel, and 1/1.41 for packing. Tentative interpretations of these differences are discussed. (Author) |
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| SCALES FOR SUBJECTIVE DISTANCE |
01 NOV 1960 |
|
| Authors:
THEODOR KUNNAPAS; STOCKHOLM UNIV (SWEDEN)
|
| Scale values were obtained for subjective distance by means of the method of ratio estimation. In three experiments different stimulus ranges of the objective distances were used. It was found that: (1) Subjective distance is a power function of the objective distance; and (2) The exponent of the function varies with the stimulus range. (Author) |
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| Exercise in Alpha Programming: Table of Molecular A and B Functions. |
NOV 1960 |
|
| Authors:
STOCKHOLM UNIV (SWEDEN)
|
| A program was made using the direct Besk code for the molecular A and B functions. These functions were printed in a duplicated table still available at the Institute of Theoretical Physics at the University of Stockholm. The index here goes from 0 to 8 and the A and B functions are printed for arguments alpha and beta between 0 and 50. In the region between 0 and 10 the ... |
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| PSYCHOPHYSICAL RELATIONS IN THE VISUAL PERCEPTION OF LENGTH, AREA AND VOLUME |
26 OCT 1960 |
|
| Authors:
Gosta Ekman; KENNETH JUNGE; STOCKHOLM UNIV (SWEDEN)
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| Subjective length, area and volume as functions of the corresponding stimulus variables were studied in three experiments. The exponents of the psychophysical power functions scattered around 1 for perception of real space. For perspective drawings of cubes and spheres, however, the exponents were about 0.75. It was tentatively concluded that perspective is an insufficient cue to visual volume. The results are discussed with special reference to certain cartographic symbols representing ... |
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| AN APPARATUS FOR EXPERIMENTS ON VELOCITY PERCEPTION |
19 OCT 1960 |
|
| Authors:
GUNNAR LENNING; Madjid Mashhour; STOCKHOLM UNIV (SWEDEN)
|
| An apparatus is described, which is being used for certain experiments on velocity perception and which has to meet certain specified requirements. The electronical set-up permits continuous and independent variation in any direction of the velocity of two stimulus patterns from zero (below the absolute threshold) to a high value (beyond the upper threshold). (Author) |
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| ON THE BAND THEORY OF MOLECULAR CRYSTALS |
AUG 1960 |
|
| Authors:
Stig Flodmark; STOCKHOLM UNIV (SWEDEN)
|
| The orbitals of the electrons in a crystal adapted to the translational symmetry of the atomic framework are the so-called Bloch functions. In the the crystal orbital method presented, the use of these orbitals in the Schrodinger equation gives one secular equation for every wave vector. The basic orbitals in this secular equation are the different atomic orbitals for the atoms in the unit cell. (Author) |
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| ON VERTICAL MOTIONS AND TRANSVERSAL CIRCULATIONS AT THE EASTERN AND WESTERN SIDE ON LONG-WAVE DISTURBANCES IN THE SUMMER SUBTROPICAL JETSTREAM |
30 SEP 1959 |
|
| Authors:
FRIEDRICH DEFANT; STOCKHOLM UNIV (SWEDEN)
|
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| A SYNOPTIC INVESTIGATION OF THE FLOW AND MASS FIELD IN THE CLOSE VICINITY OF THE SUMMER SUBTROPICAL JET STREAM RELATIVE TO THE JET-AXIS |
30 SEP 1959 |
|
| Authors:
FRIEDRICH DEFANT; STOCKHOLM UNIV (SWEDEN)
|
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| INVESTIGATIONS ON THE DETAILED STRUCTURE OF THE ATMOSPHERE IN NORTHERN HEMISPHERE MIDSUMMER (15-20 JULY 1957, IGY-DATA) |
01 SEP 1959 |
|
| Authors:
Friedrich Defant; STOCKHOLM UNIV (SWEDEN)
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| HORIZONTAL AND VERTICAL WIND PROFILES OF THE SUBTROPICAL AND POLAR JET FOR JANUARY 1-7, 1956 AND THE VARIATION OF THE EQUIVALENT BAROTROPIC LEVEL |
02 JUL 1959 |
|
| Authors:
HASSAM TABA; STOCKHOLM UNIV (SWEDEN)
|
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