scholarly journals On the Change of the Osmotic Pressure of Solutions of certain Colloids under the Influence of Salt Solutions

1922 ◽  
Vol 16 (4) ◽  
pp. 449-454 ◽  
Author(s):  
Daizo Ogata
Keyword(s):  
Osmotic Pressure ◽  
Salt Solutions

GERMINATION OF ALFALFA VARIETIES IN SOLUTIONS OF VARYING OSMOTIC PRESSURE AND RELATIONSHIP TO WINTER HARDINESS

1959 ◽  
Vol 39 (3) ◽  
pp. 384-394 ◽  
Author(s):  
D. H. Heinrichs
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Laboratory Experiments ◽  
Reliable Method ◽  
Winter Hardiness ◽  
The Other ◽  
General Tendency ◽  
Salt Solutions ◽  
Sodium Chloride Solutions ◽  
Alfalfa Varieties

Two laboratory experiments were conducted to evaluate the reliability of amount of germination in solutions of varying osmotic pressure, as a means of separating alfalfa varieties into winter-hardiness classes. In one test 23 varieties or strains were studied, and in the other 36. It was found that significant differences exist between certain alfalfa varieties in their ability to germinate in sucrose or sodium chloride solutions of 3, 6, and 9 atmospheres. There is a general tendency for non-hardy varieties to germinate more rapidly and more completely than hardy ones but there are many exceptions to this trend. Germination in solutions of 6 atmospheres osmotic pressure at 5 days gave the best separation of varieties on the basis of their ability to germinate. Germination was generally better in solutions of sucrose at 6 atmospheres osmotic pressure than in solutions of sodium chloride of the same osmotic pressure but several varieties germinated equally well in either solution. The results indicate that germinating alfalfa in sugar or salt solutions is not a reliable method for differentiating alfalfa varieties into winter hardiness classes.

scholarly journals THE SWELLING AND OSMOTIC PRESSURE OF GELATIN IN SALT SOLUTIONS

1926 ◽  
Vol 8 (4) ◽  
pp. 317-337 ◽  
Author(s):  
John H. Northrop ◽  
M. Kunitz
Keyword(s):  
Bulk Modulus ◽  
Osmotic Pressure ◽  
Salt Solution ◽  
Modulus Of Elasticity ◽  
Elastic Limit ◽  
Ion Concentration ◽  
Salt Solutions ◽  
Original Volume ◽  
Expected Result ◽  
Do So

1. The swelling and the osmotic pressure of gelatin at pH 4.7 have been measured in the presence of a number of salts. 2. The effect of the salts on the swelling is closely paralleled by the effect on the osmotic pressure, and the bulk modulus of the gelatin particles calculated from these figures is constant up to an increase in volume of about 800 per cent. As soon as any of the salts increase the swelling beyond this point, the bulk. modulus decreases. This is interpreted as showing that the elastic limit has been exceeded. 3. Gelatin swollen in acid returns to its original volume after removal of the acid, while gelatin swollen in salt solution does not do so. This is the expected result if, as stated above, the elastic limit had been exceeded in the salt solution. 4. The modulus of elasticity of gelatin swollen in salt solutions varies in the same way as the bulk modulus calculated from the osmotic pressure and the swelling. 5. The increase in osmotic pressure caused by the salt is reversible on removal of the salt. 6. The observed osmotic pressure is much greater than the osmotic pressure calculated from the Donnan equilibrium except in the case of AlCl3, where the calculated and observed pressures agree quite closely. 7. The increase in swelling in salt solutions is due to an increase in osmotic pressure. This increase is probably due to a change in the osmotic pressure of the gelatin itself rather than to a difference in ion concentration.

THE NUMBER OF SUBUNITS IN THE MOLECULE OF HORSE HEMOGLOBIN

1956 ◽  
Vol 34 (4) ◽  
pp. 411-425 ◽  
Author(s):  
M. E. Reichmann ◽  
J. Ross Colvin
Keyword(s):  
Light Scattering ◽  
Osmotic Pressure ◽  
Performic Acid ◽  
Approach To Equilibrium ◽  
Salt Solutions ◽  
Covalent Bonds ◽  
Molecular Weights ◽  
Equilibrium Sedimentation ◽  
Hemoglobin Molecule ◽  
Ph Range

The molecular weights of horse hemoglobin, horse globin, and performic acid oxidized horse globin were determined by osmotic pressure, by an approach to equilibrium sedimentation, and by light scattering (except hemoglobin) at pH 1.5 to 2.5 in 0.05 M NaCl. Sedimentation coefficients were determined for these materials over the same pH range and electrophoretic analyses were made from pH 1.5 to 4.0. The results show that in dilute salt solutions below pH 2.5 horse hemoglobin dissociates to four subunits all approximately equal in mass but at least two of which differ electrokinetically and therefore in composition. The subunits are probably held together in the native hemoglobin molecule only by non-covalent bonds.

Continuity of States in Cholesteric - Line Hexatic Transition in Univalent and Polyvalent Salt DNA Solutions

2014 ◽  
Vol 1619 ◽  
Author(s):  
Selcuk Yasar ◽  
Rudolf Podgornik ◽  
V. Adrian Parsegian
Keyword(s):  
Osmotic Pressure ◽  
Dna Polymorphism ◽  
Electrolyte Solutions ◽  
Experimental Methodology ◽  
Salt Solutions ◽  
Important Advance ◽  
Orthorhombic Crystal ◽  
First Order ◽  
Small Density ◽  
Dna Solutions

ABSTRACTWith increasing density imposed by external osmotic pressure, DNA in univalent salt solutions (e.g., NaCl) is known to go through a set of ordered mesophases, eventually crystallizing into an orthorhombic crystal. While the transition from the cholesteric to the line hexatic (LH) phase has been observed before, it has remained unclear whether the transition is of second order or first order. We use the small but accurately measurable temperature dependence of the osmotic pressure of a PEG solution to fine-regulate the osmotic stress with which it acts on the DNA subphase. This allows us to set the osmotic pressure to an accuracy never achieved before. This advance in experimental methodology allows us then to detect small but nevertheless finite changes in the density of DNA as it goes through the cholesteric → LH transition. In this way, we first determine experimentally the small density change that occurs at the cholesteric → LH phase transition. Further, we establish that this small density discontinuity of Na-DNA is merely increased when polyvalent salt Co(NH3)6Cl3, i.e. CoHex, is added to the solution. Increasing CoHex concentration finally leads to a phase separation at zero imposed osmotic pressure. Establishing a continuity of thermodynamic states for the cholesteric → LH transition and DNA condensation, thought to be completely unrelated before, represents an important advance in our understanding of DNA polymorphism in electrolyte solutions.

The Osmotic Pressure of Polyelectrolyte in Neutral Salt Solutions

1970 ◽  
Vol 74 (4) ◽  
pp. 944-946 ◽  
Author(s):  
Akira Takahashi ◽  
Narundo Kato ◽  
Mitsuru Nagasawa
Keyword(s):  
Osmotic Pressure ◽  
Neutral Salt ◽  
Salt Solutions

Changes in erythrocytes resulting from excessive shrinking

1961 ◽  
Vol 16 (4) ◽  
pp. 665-668 ◽  
Author(s):  
Darío Valdivieso ◽  
F. R. Hunter
Keyword(s):  
Osmotic Pressure ◽  
Ringer Solution ◽  
Irreversible Change ◽  
Salt Solutions ◽  
Normal Cells ◽  
Chicken Erythrocytes

A change occurs in chicken erythrocytes during suspension in salt solutions or solutions of nonelectrolytes in Locke-Ringer solution with an osmotic pressure three to four times that of the original cells. If the cells shrink and then swell in less than 10 min this change does not occur. The changed cells are more fragile than normal cells. They have less potassium but more sodium. Evidently when these erythrocytes shrink to a certain point there is some irreversible change. The mechanism for maintaining the cation imbalance between the cell and its environment can break down, and the cells can lose potassium and gain sodium. The cells are highly fragile, and consequently they hemolyze under various circumstances which are not hemolytic to normal cells. Submitted on November 14, 1960

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