scholarly journals KINETICS OF THE SWELLING OF CELLS AND TISSUES

1927 ◽  
Vol 11 (1) ◽  
pp. 43-56 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Sea Water ◽  
Distilled Water ◽  
Rate Of Increase ◽  
Kinetics Of

The rate of swelling of Arbacia eggs in dilute sea water, studied by Lillie and by Lucke and McCutcheon, may be expressed by the formulæ derived for the rate of increase in volume of a solution enclosed in a collodion sac. The rate of swelling of slices of carrot in distilled water, measured by Stiles and Jørgensen, may be expressed by the equation derived previously for the swelling of similarly shaped blocks of gelatin.

scholarly journals THE KINETICS OF PENETRATION

1938 ◽  
Vol 22 (2) ◽  
pp. 147-163 ◽  
Author(s):  
A. G. Jacques
Keyword(s):  
Osmotic Pressure ◽  
Free Space ◽  
Partition Coefficients ◽  
Sea Water ◽  
Intact Cell ◽  
Linear Part ◽  
Osmotic Concentration ◽  
Intact Cells ◽  
Rate Of Increase ◽  
Kinetics Of

When Valonia cells are impaled on capillaries, it is in some ways equivalent to removing the comparatively inelastic cellulose wall. Under these conditions sap can migrate into a free space and it is found that on the average the rate of increase of volume of the sap is 15 times what it is in intact cells kept under comparable conditions. The rate of increase of volume is a little faster during the first few hours of the experiment, but it soon becomes approximately linear and remains so as long as the experiment is continued. The slightly faster rate at first may mean that the osmotic pressure of the sap is approaching that of the sea water (in the intact cell the sap osmotic pressure is always slightly above that of the sea water). This might result from a more rapid entrance of water than of electrolyte, as would be expected when the restriction of the cellulose wall was removed. During the linear part of the curve the osmotic concentration and the composition of the sap suffer no change, so that entrance of electrolyte must be 15 times as fast in the impaled cells as it is in the intact cells. The explanation which best accords with the facts is that in the intact cell the entrance of electrolyte tends to increase the osmotic pressure. As a consequence the protoplasm is partially dehydrated temporarily and it cannot take up more water until the cellulose wall grows so that it can enclose more volume. The dehydration of the protoplasm may have the effect of making the non-aqueous protoplasm less permeable to electrolytes by reducing the diffusion and partition coefficients on which the rate of entrance depends. In this way the cell is protected against great fluctuations in the osmotic concentration of the sap.

Effect of aging on the penetration resistance of sands

1995 ◽  
Vol 32 (5) ◽  
pp. 767-782 ◽  
Author(s):  
R.C. Joshi ◽  
Gopal Achari ◽  
Shenbaga R. Kaniraj ◽  
H. Wijeweera
Keyword(s):  
Sea Water ◽  
Penetration Resistance ◽  
Distilled Water ◽  
Freezing And Thawing ◽  
Water Penetration ◽  
River Sand ◽  
Sea Sand ◽  
Rate Of Increase ◽  
Sand Particles ◽  
Masonry Sand

The main objective of this study was to understand the effect of aging on the penetration resistance of freshly deposited sands. Two types of sand, locally available river sand used as masonry sand and Beaufort Sea sand, were selected for the study. The sands were allowed to age under a constant stress of 100 kPa in a specially designed apparatus in a dry state, as well as submerged in distilled water and in simulated sea water. Penetration resistance of the sand beds was measured periodically by pushing 4 probes into the sand bed. Mineralogical and fabric studies on freshly deposited and aged sand samples were conducted to detect the effect of aging, if any, on sand grains. The results indicate that aging significantly increases the penetration resistance of sands. The rate of increase in penetration resistance was higher for the submerged sand as compared with the dry sand. The increase in penetration resistance of the sand in a dry state was attributed to rearrangement of sand grains. In the submerged state, besides the rearrangement of sand particles, partial cementation caused by precipitation of salts and probably also silica on the sand grains and in the pores resulted in the larger increase in the penetration resistance. Key words : sand, aging, penetration resistance, freezing and thawing, sea water, distilled water.

scholarly journals THE KINETICS OF PENETRATION

1939 ◽  
Vol 22 (6) ◽  
pp. 757-773 ◽  
Author(s):  
A. G. Jacques
Keyword(s):  
Natural Variation ◽  
Sea Water ◽  
Intact Cell ◽  
The State ◽  
Osmotic Concentration ◽  
Linear Rate ◽  
Partial Dissipation ◽  
Rate Of Increase ◽  
The Difference ◽  
Kinetics Of

When cells of Halicystis are impaled on a capillary so that space is provided into which the sap can migrate, the rate of entrance of water and of electrolyte is increased about 10-fold. In impaled Valonia cells the rate is increased about 15-fold. After a relatively rapid non-linear rate of increase of sap volume immediately after impalement (which may possibly represent the partial dissipation of the difference of the osmotic energy between intact and impaled cells) the volume increases at a linear rate, apparently indefinitely. Since the halide concentration of the sap at the end of the experiment is (within the limits of natural variation) the same as in the intact cell, we conclude that electrolyte also enters the sap about 10 times as fast as in the intact cell. As in the case of Valonia we conclude that there is a mechanism whereby in the intact cell the osmotic concentration of the sap is prevented from greatly exceeding that of the sea water. This may be associated with the state of hydration of the non-aqueous protoplasmic surfaces.

Examination for Degradation Paths of Butyltin Compounds in Natural Waters

1992 ◽  
Vol 25 (11) ◽  
pp. 117-124 ◽  
Author(s):  
N. Watanabe ◽  
S. Sakai ◽  
H. Takatsuki
Keyword(s):  
Glass Fiber ◽  
Half Life ◽  
Natural Waters ◽  
Sea Water ◽  
Degradation Process ◽  
Distilled Water ◽  
Degradation Rates ◽  
Clean Area ◽  
Butyltin Compounds ◽  
Sun Light

Examination of individual degradation paths (biodegradation and photolysis) of butyltin compounds (especially tributyltin: TBT) in natural waters was performed. Biodegradation of TBT and dibutyltin (DBT) in an unfiltered sea water in summer is rather fast; their half life is about a week. But pretreatment with glass fiber filter makes the half life of TBT much longer (about 80 days). Photolysis of TBT in sea water by sun light is rapid (half life is about 0.5 days), and faster than in distilled water or in fresh water. Degradation rates of each process for TBT are calculated in various conditions of sea water, and contribution rates are compared. Biodegradation will be the main degradation process in an “SS-rich” area such as a marina, but photolysis will exceed that in a “clean” area. Over all half lives of TBT in sea water vary from 6 days to 127 days considering seasons and presence of SS.

Specific heat of mixtures of kaolin with sea water or distilled water for their use in thermotherapy

2017 ◽  
Vol 130 (1) ◽  
pp. 479-484 ◽  
Author(s):  
M. M. Mato ◽  
L. M. Casás ◽  
J. L. Legido ◽  
C. Gómez ◽  
L. Mourelle ◽  
...  
Keyword(s):  
Specific Heat ◽  
Sea Water ◽  
Distilled Water

scholarly journals THE KINETICS OF PENETRATION

1937 ◽  
Vol 20 (5) ◽  
pp. 737-766 ◽  
Author(s):  
A. G. Jacques
Keyword(s):  
Sea Water ◽  
Surface Layers ◽  
Marked Contrast ◽  
External Concentration ◽  
Protoplasmic Surface ◽  
Kinetics Of ◽  
External Ph

When 0.1 M NaI is added to the sea water surrounding Valonia iodide appears in the sap, presumably entering as NaI, KI, and HI. As the rate of entrance is not affected by changes in the external pH we conclude that the rate of entrance of HI is negligible in comparison with that of NaI, whose concentration is about 107 times that of HI (the entrance of KI may be neglected for reasons stated). This is in marked contrast with the behavior of sulfide which enters chiefly as H2S. It would seem that permeability to H2S is enormously greater than to Na2S. Similar considerations apply to CO2. In this respect the situation differs greatly from that found with iodide. NaI enters because its activity is greater outside than inside so that no energy need be supplied by the cell. The rate of entrance (i.e. the amount of iodide entering the sap in a given time) is proportional to the external concentration of iodide, or to the external product [N+]o [I-lo, after a certain external concentration of iodide has been reached. At lower concentrations the rate is relatively rapid. The reasons for this are discussed. The rate of passage of NaI through protoplasm is about a million times slower than through water. As the protoplasm is mostly water we may suppose that the delay is due chiefly to the non-aqueous protoplasmic surface layers. It would seem that these must be more than one molecule thick to bring this about. There is no great difference between the rate of entrance in the dark and in the light.

Taste by Touch: Some Experiments with Octopus

1963 ◽  
Vol 40 (1) ◽  
pp. 187-193
Author(s):  
M. J. WELLS
Keyword(s):  
Hydrochloric Acid ◽  
Fresh Water ◽  
Sea Water ◽  
Olfactory Organ ◽  
Distilled Water ◽  
Quinine Sulphate ◽  
Human Tongue ◽  
Half Strength

1. A method of teaching Octopus chemotactile discriminations is described. 2. The animals can be shown to be capable of distinguishing by touch between porous objects soaked in plain sea water and sea water with hydrochloric acid, sucrose or quinine sulphate added. 3. They can detect these substances in concentrations at least 100 times as dilute as the human tongue is capable of detecting them in distilled water. 4. They can be trained to distinguish between equimolar (0.2 mM) solutions of hydrochloric acid, sucrose and quinine. 5. They can also be trained to distinguish between sea water and fresh water or half-strength sea water or sea water with twice the usual quantity of salt. 6. The function of the ‘olfactory organ’ is discussed. 7. Chemotactile learning is discussed in relation to the means by which Octopus finds its way about the territory around its ‘home’

Experiments on Substrate Selection by Corophium Species: Films and Bacteria on Sand Particles

1964 ◽  
Vol 41 (3) ◽  
pp. 499-511
Author(s):  
P. S. MEADOWS
Keyword(s):  
Ionic Strength ◽  
Sea Water ◽  
Distilled Water ◽  
Substrate Selection ◽  
Corophium Volutator ◽  
Simple Method ◽  
Substrate Preferences ◽  
Solutions Of Electrolytes ◽  
Sand Particles ◽  
Micro Organisms

1. A simple method is described for determining the substrate preferences of Corophium volutator (Pallas) and Corophium arenarium Crawford. 2. If offered a choice of its own substrate with that of the other species each prefers its own. 3. Level of illumination and colour of substrate have little effect on choice. An animal's size and hence its age has little effect on its substrate preferences. 4. C. volutator prefers a substrate previously maintained under anaerobic conditions, C. arenarium vice versa. 5. Treatments which kill, inactivate, or remove micro-organisms render sands unattractive to Corophium. These include boiling, acid-cleaning, drying, and soaking in fixatives or distilled water. Attempts to make these sands attractive again failed. 6. Distilled water, and solutions of the non-electrolytes sucrose and glycerol at the same osmotic pressure as sea water, induce many bacteria to desorb from sand particles; smaller numbers are desorbed in the presence of solutions of electrolytes at the same ionic strength as sea water (NaCl, Na2SO4, KC1, MgSO4, MgCl2, CaCl2). Of all these, only distilled water and solutions of MgCl2 and CaCl2 reduce the attractive properties of sands. Hence the loss of bacteria from the surface of sand grains, though related to the ionic strength and composition of the medium, is not necessarily associated with a substrate becoming unattractive.

The effect of external salinity on drinking rate and rectal secretion in the larvae of the saline-water mosquito Aedes taeniorhynchus

1977 ◽  
Vol 66 (1) ◽  
pp. 97-110
Author(s):  
T. J. Bradley ◽  
J. E. Phillips
Keyword(s):  
Sea Water ◽  
External Medium ◽  
Narrow Range ◽  
Saline Water ◽  
Fluid Secretion ◽  
Osmotic Concentration ◽  
Drinking Rate ◽  
Aedes Taeniorhynchus ◽  
External Salinity ◽  
Kinetics Of

1. The drinking rate of the saline-water mosquito larva Aedes taeniorhyncus (100 nl.mg-1.h-1) is unaffected by the salinity of the external medium, but is directly proportional to the surface area of the animal. 2. Haemolymph Na+, Mg2+, K+, Cl-, SO42- and osmotic concentrations were measured in larvae adapted to 10%, 100% and 200% seawater and were found to be regulated within a narrow range. 3. With the exception of potassium, ionic concentrations in rectal secretion were found to increase with increasing concentrations of the sea water in which larvae were reared. 4. The osmotic concentration of rectal secretion was unaffected by changes in haemolymph osmotic concentration but did rise when sodium or chloride concentrations of the haemolymph were increased. High levels of these ions also stimulated the rate of fluid secretion. 5. Transport of chloride and sodium by the rectum exhibits the kinetics of allosteric rather than classical enzymes.

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