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

scholarly journals THE SWELLING PRESSURE OF GELATIN AND THE MECHANISM OF SWELLING IN WATER AND NEUTRAL SALT SOLUTIONS

1926 ◽  
Vol 10 (1) ◽  
pp. 161-177 ◽  
Author(s):  
John H. Northrop ◽  
M. Kunitz
Keyword(s):  
Osmotic Pressure ◽  
Cold Water ◽  
Soluble Fraction ◽  
Swelling Pressure ◽  
Insoluble Fraction ◽  
Neutral Salt ◽  
Salt Solutions ◽  
Low Viscosity ◽  
Or Groups ◽  
Different Temperatures

1. A method is described for measuring the swelling pressure of solid gelatin. 2. It was found that this pressure increases rapidly between 15° and 37°C., and that the percentage change is nearly independent of the concentration of gelatin. 3. It is suggested that this pressure is due to the osmotic pressure of a soluble constituent of the gelatin held in the network of insoluble fibers, and that gelatin probably consists of a mixture of at least two substances or groups of substances, one of which is soluble in cold water, does not form a gel, and has a low viscosity and a high osmotic pressure. The second is insoluble in cold water, forms a gel in very low concentration, and swells much less than ordinary gelatin. 4. Two fractions, having approximately the above properties, were isolated from gelatin by alcohol precipitation at different temperatures. 5. Increasing the temperature and adding neutral salts greatly increase the pressure of the insoluble fraction and have little effect on that of the soluble fraction. 6. Adding increasing amounts of the soluble fraction to the insoluble one results in greater and greater swelling. 7. These results are considered as evidence for the idea that the swelling of gelatin in water or salt solutions is an osmotic phenomenon, and that gelatin consists of a network of an insoluble substance enclosing a solution of a soluble constituent.

scholarly journals Effect of pyrolysis temperature on Si release of alkali-enhanced Si-rich biochar and plant response

Biochar ◽  
2021 ◽  
Author(s):  
Meng Wang ◽  
Negar D. Tafti ◽  
Jim J. Wang ◽  
Xudong Wang
Keyword(s):  
Rice Straw ◽  
Rice Husk ◽  
Pyrolysis Temperature ◽  
Weak Acid ◽  
Rice Grain ◽  
Neutral Salt ◽  
Salt Solutions ◽  
Plant Disease Control ◽  
Si Content ◽  
Lower Temperature

AbstractRecent studies have shown that silicon (Si) dissolution from biochar may be influenced by the pyrolysis temperature. In addition, the enhancement of biochar by treatment with alkali has been proposed to produce a Si source that can be used for environmentally friendly plant disease control. In this study, biochars from rice straw and rice husk pretreated with KOH, CaO and K2CO3 and then pyrolyzed at 350, 450 and 550 °C were prepared to evaluate the effects of pyrolysis temperature on Si release and plant uptake from alkali-enhanced Si-rich biochar. Extractable Si and dissolution Si from the prepared biochars were assessed by different short-term chemical methods and long-term (30-day) release in dilute acid and neutral salt solutions, respectively, along with a rice potting experiment in greenhouse. For both rice straw- and husk-derived alkali-enhanced biochars (RS-10KB and HS-10K2B, respectively), increasing the pyrolysis temperature from 350 to 550 °C generally had the highest extractable Si and increased Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN) designated for fertilizer Si by 61–142%, whereas non-enhanced biochars had more extractable Si at 350 °C. The alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days. In addition, alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag). Overall, this study demonstrated that 550 °C is more efficient than lower pyrolysis temperature for preparing alkali-enhanced biochar to improve Si release for plant growth.

The effects of aqueous neutral-salt solutions on the melting temperatures of deoxyribonucleic acids

Biopolymers ◽  
1971 ◽  
Vol 10 (1) ◽  
pp. 47-68 ◽  
Author(s):  
Dieter W. Gruenwedel ◽  
Chi-Hsia Hsu ◽  
Don S. Lu
Keyword(s):  
Neutral Salt ◽  
Salt Solutions ◽  
Melting Temperatures

scholarly journals The effects of aqueous neutral-salt solutions on the melting temperatures of deoxyribonuclcic acids

Biopolymers ◽  
1971 ◽  
Vol 10 (6) ◽  
pp. 1103-1103
Author(s):  
Dieter W. Gruenwedel ◽  
Cih-Hsia Hsu ◽  
Don S. Lu
Keyword(s):  
Neutral Salt ◽  
Salt Solutions ◽  
Melting Temperatures

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 STUDIES ON THE FORMATION OF COLLAGEN

1958 ◽  
Vol 107 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Jerome Gross
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Guinea Pigs ◽  
Caloric Intake ◽  
Neutral Salt ◽  
Salt Solutions ◽  
Citrate Buffer ◽  
Continuous Growth ◽  
Dermal Collagen ◽  
Low Levels

The total amount of neutral salt-extractible collagen in the skin of growing, suckling guinea pigs amounted to about 10 per cent of the total collagen of the dennis. This is roughly equivalent to a 1 to 2 day increment in dermal collagen incident to growth. Fourteen days of static weight maintained by limited caloric intake reduced the neutral salt-extractible collagen to very low levels. Following this period, 5 to 7 days of steady weight gain induced by ad lib. feeding was required to produce significant increases in this collagen fraction. Return to control levels occurred within 12 days of continuous growth. The amount of collagen extracted from the dermis of young guinea pigs with cold neutral salt solutions varied directly with growth rate (weight gain) and was greatly diminished after short periods of restricted caloric intake. Two days of fasting diminished the total extracted collagen by one-half. Three consecutive extractions with citrate buffer pH, 3.5, of the residues remaining after exhaustive saline extraction removed 40 per cent more collagen from the skins of actively growing animals than from those of animals fasted for 2 days. However, subsequent extraction of residues with dilute acetic acid equalized the total amount of collagen extracted at acid pH from the two groups. The viscosity of cold neutral extracts was unrelated to the concentrations of non-collagenous proteins and carbohydrates but varied directly with the collagen content.

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