scholarly journals Activity-measurement by the partition method.—I

1924 ◽  
Vol 106 (737) ◽  
pp. 243-250 ◽  
Keyword(s):  
Aqueous Solution ◽  
Electrostatic Potential ◽  
Special Interest ◽  
Freezing Point ◽  
Activity Measurement ◽  
Freezing Point Depression ◽  
Concentration Cell ◽  
Low Concentrations ◽  
The Mean ◽  
Partition Method

In the light of Milner’s calculation of the mean electrostatic potential in chaos of ions, activity-measurement is of special interest at low concentrations aqueous, and still lower concentrations in non-aqueous solution, owing to the simple and peculiar dilution law which the theory predicts for such consentrations. The methods which have chiefly been relied on for such data—that of the Freezing-point depression and that of the concentration cell-—tend to lose recision at low concentrations, owing, in the former, to the smallness of the depression measured, and in the latter, to polarisation effects.

287. The freezing-point of milk. I. The freezing-point and solids-not-fat content of the milk of individual cows throughout a period of lactation

1941 ◽  
Vol 12 (3) ◽  
pp. 315-321 ◽  
Author(s):  
R. Aschaffenburg ◽  
P. L. Temple
Keyword(s):  
Freezing Point ◽  
Extreme Case ◽  
Fat Content ◽  
The State ◽  
Freezing Point Depression ◽  
The Mean ◽  
Time Of Year

The results of regular determinations of the freezing-point and solids-not-fat content of the milk of three Shorthorn cows over a period of more than six months are reported.The known constancy of the freezing-point depression was confirmed, the Δ values deviating generally by less than 2% and, in the most extreme case, by no more than 3·5% from the mean of 0·546 ± 0·002° C. No evidence was found of any influence of the state of lactation on the freezing-point depression, but a slight but definite decrease persisting for some weeks occurred at the time of year at which ample supplies of spring pasture became available to the animals.

Osmoregulation in Trichocorixa verticalis interiores Sailer (Hemiptera, Corixidae) — an inhabitant of Saskatchewan saline lakes, Canada

1975 ◽  
Vol 53 (9) ◽  
pp. 1207-1212 ◽  
Author(s):  
Patricia I. Tones ◽  
U. T. Hammer
Keyword(s):  
Saline Lakes ◽  
Freezing Point ◽  
Saline Water ◽  
Adult Population ◽  
Ionic Composition ◽  
Tolerance Limit ◽  
Freezing Point Depression ◽  
Wide Range ◽  
The Mean

Results of freezing point depression determinations of haemolymph show that first instars, third instars, and adults of Trichocorixa verticalis interiores have well-developed powers of osmoregulation and can hyporegulate in saline water. This species can osmoregulate equally well at 13, 20, and 25 °C but the mean tolerance limit decreases as the temperature increases. T. verticalis interiores is also tolerant to changes in ionic composition. The osmoregulation of this species is similar to that of Sigara stagnalis rather than most Corixidae which are unable to hyporegulate. T. verticalis interiores was collected quantitatively from six athalassic saline lakes which were selected to represent a wide range of salinities. The maximum adult population and conductivity and ionic composition of the water are reported for each lake.

Osmoregulation in Ligia Oceanica and Idotea Granulosa

1963 ◽  
Vol 40 (2) ◽  
pp. 381-392
Author(s):  
MARY E. TODD
Keyword(s):  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
External Concentration ◽  
Osmotic Concentration ◽  
Test Range ◽  
The Mean ◽  
The Difference ◽  
Idotea Granulosa

1. The osmoregulatory response of Ligia oceanica and Idotea granulosa to the range of the experimental variables was similar. They were both hyperosmotic relative to the medium and the difference between internal and external concentration increased as the salinity of the medium decreased. 2. In 100% sea water the osmotic concentration of the blood of Ligia oceanica was markedly above that of the medium, whereas in Idotea granulosa the blood was only marginally hyperosmotic. 3. In Ligia oceanica the blood concentration changed little in 100 and 75% sea water, but dropped significantly between 75 and 50% sea water, whereas blood concentration in Idotea granulosa dropped significantly throughout the test range of salinities. 4. The more efficient osmoregulation of Ligia oceanica in 25% sea water is reflected in the mean freezing-point depression of the blood, Δi = 1.65, compared with Δi = 0.90 in Idotea granulosa. 5. In both species the osmotic concentration of the blood was influenced by season, by temperature and by a temperature-salinity interaction. 6. Neither size nor sex of the animal influenced osmotic concentration of the blood.

Ice Slurry Generation for Direct Contact Cooling

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Koji Fumoto ◽  
Toshiki Sato ◽  
Tsuyoshi Kawanami ◽  
Takao Inamura
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Direct Contact ◽  
Freezing Point ◽  
Solution Concentration ◽  
Freezing Point Depression ◽  
Ice Slurry ◽  
Supercooling Degree ◽  
Basic Characteristics ◽  
Pressure Shift Freezing

Ice slurry has attracted a great deal of attention as a coolant for direct contact cooling. In this study, we generated ice slurry by the method of pressure shift freezing (PSF), which is based on the freezing-point depression of an aqueous solution at high-pressure conditions. As a result, the basic characteristics of the ice slurry generation are clarified. Moreover, the physical properties of the ice slurry indicate that the shape of an ice particle in the ice slurry is strongly affected by both the supercooling degree and the aqueous solution concentration.

Localization of calcium and zinc in the sperm storage tubules of chicken, quail and turkey using X-ray microanalysis

Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale
Keyword(s):  
Calcium Concentration ◽  
Sperm Storage ◽  
X Ray ◽  
Elemental Concentrations ◽  
Low Concentrations ◽  
Intracellular Content ◽  
Wet Weight ◽  
The Mean ◽  
Sperm Storage Tubules ◽  
Scanning Electron

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.

Depression of freezing temperature of water and water solutions in porous materials

1989 ◽  
Vol 54 (10) ◽  
pp. 2644-2647 ◽  
Author(s):  
Petr Schneider ◽  
Jiří Rathouský
Keyword(s):  
Water Vapor ◽  
Porous Materials ◽  
Inorganic Salt ◽  
Freezing Point ◽  
Freezing Temperature ◽  
Inorganic Salts ◽  
Freezing Point Depression ◽  
Salt Solutions ◽  
Water Solutions

In porous materials filled with water or water solutions of inorganic salts, water freezes at lower temperatures than under normal conditions; the reason is the decrease of water vapor tension above the convex meniscus of liquid in pores. The freezing point depression is not very significant in pores with radii from 0.05 μm to 10 μm (about 0.01-2.5 K). Only in smaller pores, especially when filled with inorganic salt solutions, this depression is important.

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