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567. Molecular weight determinations with a magnetically supported ultracentrifuge
Classified
208
Abstracts
techniques explained. The possibility of further mechanical and thermal treatment of the frozen material is considered and it is shown that automatic regulation of the sublimation phase is necessary. The economic aspects of the freeze-drying process are briefly reviewed. (in French) (Author, modified) L. Rey,
Le Vide, 17 (101).
37.
Metallurgy,
Sept./Ott.
1962, 428-444.
Inorganic Chemistry, Chemistry
Gases
evolved from steel in vacuum extraction at 600°C. Greaf Britain. The authors produce some evidence that at elevated temperature some of the hydrogen contained in the steel may react with any carbon present to form hydrocarbons which are pumped off with the remaining hydrogen during It is therefore essential that precautions be vacuum extraction. taken to ensure their complete decomposition or the hydrogen (with useful bibliography) figures for the steel will be too low. w. .I. s. K. Sachs 373-374.
and
M.
Odger,
Nature,
197
(4865).
26 Jan.
1963.
37 : 53 : 41 565. Sintering parts from beryllium powder. Great Brifain. The Atomic Weapons Research Establishment at Aldermaston has acquired a large vacuum furnace with a Both chamber chamber 48 in. in diameter and 60 in. deep. and lid are dimensioned so as to act as a press frame of a 100 ton ram by means of which powdered beryllium can be empacted after sintering. The furnace works at a pressure of 10e3 torr and special precautions are taken to protect the operator from w. .I. s. poisonous fumes when the furnace is opened. Anon.,
Nell, Scientist,
17 (328). 28 Feb.
1963, 461.
37 : 22 : 33 The origin of parasitic currents in high frequency mass spectroSee Abstr. No. 5 IO. meters and methods of suppression. 37 : 22 : 33 The theory of a parasitic frequency dependent current in the See Abstr. No. 511. Redhead r.f. mass spectrometer.
An inspection device See Abstr. No. 525.
for high
vacuum
electron
beam
Vacuum evaporation source with double-wall cylindrical See Abstr. No. 543. heater and nozzle outlet.
38.
Distillation,
37 : 28 furnaces.
37 : 30 graphite
Organic Chemistry, Isotopic Gas Analysis
38 : 54 566. The technique of molecular distillation : principles and industrial applications. (France). M. von Stumm, Le Vide, 17 (IOI), Sept./Ott. 1962, 445-452.
39.
Analytical 37
564.
564-569
Miscellaneous
Applications
39 567. Molecular weight determinations with a magnetically supported ultracentrifuge. U.S.4. A magnetically suspended ultracentrifuge has been used to determine the molecular weights and related properties of various substances. Techniques are described which make this apparatus particularly suitable for equilibrium studies of macromolecules in the IO5 to IO’ molecular weight range. P. E. Hexner,
et al.. J. Ph.~s. Che/fl.,
66, Oct.
1962. 1948-1951
39 A new instrument for fraction568. The zonal ultracentrifuge. ating mixtures of particles. U.S.A. The zonal ultracentrifuge is a new biophysical tool which allows particles to be separated on the basis of sedimentation rate or particle density. The rotor is a hollow cylinder with a total capacity of 1625 ml. divided by vertical septa into Two fluid-handling lines through sector-shaped compartments. the upper shaft connect the edge of the rotor and the central core with a flat rotating seal which presses against an external All operations, including introduction of the density static seal. gradient and the sample layer, and recovery of the gradient with its separated zones of particles, are carried out with the rotor spinning at speeds up to 5000 rev/min in a refrigerated evacuated The gradient is stabilized at all times by the centrichamber. Particle separation is accomplished at speeds up to fugal field. 30,000 rev/min (51,161 x g at the maximum radius of 5.08 cm). Subcellular components, including nuclei, cell membrane fragments, mitochondria, microsomes. ribosomes, and macroglobulin have been isolated using aqueous sucrose gradients. Tobacco mosaic virus and brome mosaic virus have been recovered in a high state of purity from crude extracts in one run. Types I, 11, and III polio virus have also been isolated in quantity from tissue culture fluid. A number of alternate rotor configurations now under consideration are presented together with data on the limits of rotor diameter attainable (Author) with aluminum and steel rotors. N. G. Anderson,
J. Plrys.
C/zenr.. 66, Oct.
569. Subtractionation of the Sf 20-lo5 bucket rotor. (U.S.,4 .). F. T. Lindgren, et a/., J. Phvs. Che/n..
1962. 1984-1989.
lipoproteins 66, Oct.
39 in a swinging
1962, 2007-201
I.
208
Abstracts
techniques explained. The possibility of further mechanical and thermal treatment of the frozen material is considered and it is shown that automatic regulation of the sublimation phase is necessary. The economic aspects of the freeze-drying process are briefly reviewed. (in French) (Author, modified) L. Rey,
Le Vide, 17 (101).
37.
Metallurgy,
Sept./Ott.
1962, 428-444.
Inorganic Chemistry, Chemistry
Gases
evolved from steel in vacuum extraction at 600°C. Greaf Britain. The authors produce some evidence that at elevated temperature some of the hydrogen contained in the steel may react with any carbon present to form hydrocarbons which are pumped off with the remaining hydrogen during It is therefore essential that precautions be vacuum extraction. taken to ensure their complete decomposition or the hydrogen (with useful bibliography) figures for the steel will be too low. w. .I. s. K. Sachs 373-374.
and
M.
Odger,
Nature,
197
(4865).
26 Jan.
1963.
37 : 53 : 41 565. Sintering parts from beryllium powder. Great Brifain. The Atomic Weapons Research Establishment at Aldermaston has acquired a large vacuum furnace with a Both chamber chamber 48 in. in diameter and 60 in. deep. and lid are dimensioned so as to act as a press frame of a 100 ton ram by means of which powdered beryllium can be empacted after sintering. The furnace works at a pressure of 10e3 torr and special precautions are taken to protect the operator from w. .I. s. poisonous fumes when the furnace is opened. Anon.,
Nell, Scientist,
17 (328). 28 Feb.
1963, 461.
37 : 22 : 33 The origin of parasitic currents in high frequency mass spectroSee Abstr. No. 5 IO. meters and methods of suppression. 37 : 22 : 33 The theory of a parasitic frequency dependent current in the See Abstr. No. 511. Redhead r.f. mass spectrometer.
An inspection device See Abstr. No. 525.
for high
vacuum
electron
beam
Vacuum evaporation source with double-wall cylindrical See Abstr. No. 543. heater and nozzle outlet.
38.
Distillation,
37 : 28 furnaces.
37 : 30 graphite
Organic Chemistry, Isotopic Gas Analysis
38 : 54 566. The technique of molecular distillation : principles and industrial applications. (France). M. von Stumm, Le Vide, 17 (IOI), Sept./Ott. 1962, 445-452.
39.
Analytical 37
564.
564-569
Miscellaneous
Applications
39 567. Molecular weight determinations with a magnetically supported ultracentrifuge. U.S.4. A magnetically suspended ultracentrifuge has been used to determine the molecular weights and related properties of various substances. Techniques are described which make this apparatus particularly suitable for equilibrium studies of macromolecules in the IO5 to IO’ molecular weight range. P. E. Hexner,
et al.. J. Ph.~s. Che/fl.,
66, Oct.
1962. 1948-1951
39 A new instrument for fraction568. The zonal ultracentrifuge. ating mixtures of particles. U.S.A. The zonal ultracentrifuge is a new biophysical tool which allows particles to be separated on the basis of sedimentation rate or particle density. The rotor is a hollow cylinder with a total capacity of 1625 ml. divided by vertical septa into Two fluid-handling lines through sector-shaped compartments. the upper shaft connect the edge of the rotor and the central core with a flat rotating seal which presses against an external All operations, including introduction of the density static seal. gradient and the sample layer, and recovery of the gradient with its separated zones of particles, are carried out with the rotor spinning at speeds up to 5000 rev/min in a refrigerated evacuated The gradient is stabilized at all times by the centrichamber. Particle separation is accomplished at speeds up to fugal field. 30,000 rev/min (51,161 x g at the maximum radius of 5.08 cm). Subcellular components, including nuclei, cell membrane fragments, mitochondria, microsomes. ribosomes, and macroglobulin have been isolated using aqueous sucrose gradients. Tobacco mosaic virus and brome mosaic virus have been recovered in a high state of purity from crude extracts in one run. Types I, 11, and III polio virus have also been isolated in quantity from tissue culture fluid. A number of alternate rotor configurations now under consideration are presented together with data on the limits of rotor diameter attainable (Author) with aluminum and steel rotors. N. G. Anderson,
J. Plrys.
C/zenr.. 66, Oct.
569. Subtractionation of the Sf 20-lo5 bucket rotor. (U.S.,4 .). F. T. Lindgren, et a/., J. Phvs. Che/n..
1962. 1984-1989.
lipoproteins 66, Oct.
39 in a swinging
1962, 2007-201
I.