scholarly journals Osmotic Conditions During the Embryonic and Early Larval Life of the Brook Lamprey (Lampetra Planeri)

1957 ◽  
Vol 34 (2) ◽  
pp. 237-252
Author(s):  
M. W. HARDISTY
Keyword(s):  
Water Content ◽  
Tap Water ◽  
Initial Permeability ◽  
Distilled Water ◽  
Continuous Increase ◽  
Outer Membranes ◽  
Lampetra Planeri ◽  
Short Time ◽  
Osmolar Concentration ◽  
Whole Egg

1. Observations have been made on the swelling of eggs in tap and distilled water. The rate of uptake of water through the outer membranes and the surface of the ovum fell off sharply within a short time of contact with water. In distilled water uptake into the perivitelline space was very much greater than in tap water, but there were no significant differences in the volume of the ovum itself in these two media. 2. The initial permeability of the ovum to water has been estimated as 0.049 µ3/µ2atm./min., falling after about 7 hr. to 0.003 and remaining at this level for the first 5 days of development. 3. The outer egg membranes are apparently freely permeable to water and ions, and the mean Cl concentration of the perivitelline fluid in the later stages of development was found to be only 2.4 mM/l. 4. Evidence is presented which points to a decrease in the volume of the embryo at some point between gastrulation and hatching. In tap water a contraction of the whole egg was observed from the fifth day onwards. 5. The water content of the embryo at hatching was not very much greater than that of the ovarian egg. After hatching, until the absorption of the yolk, there was a continuous increase in the fresh weight and water content of the ammocoetes. 6. The evidence suggests that the ovarian egg is in osmotic equilibrium with the peritoneal fluid (mean 110 mM/NaCl/l.). During development the osmolar concentration of the total egg fluid was reduced to values similar to those calculated from the known dilution, i.e. 30-40 mM/l. At hatching, the osmolar concentration of the embryo (80 mM/l.) was raised within a few days to 11-120 mM/l. 7. The observed reduction in Cl concentration of the whole egg was much greater than that calculated from the increases in volume. The Cl concentration of the embryo itself was reduced from an initial value of 56 to 15 mM/l. embryo fluid a week before hatching. 8. Determinations of the total Cl content of whole eggs and embryos showed a very marked loss of Cl ions in the two days following fertilization. Within 35 days after hatching the Cl level had been raised by active uptake to about four times the values at the time of hatching.

Changes in specific airway resistance during prolonged breathing of moist air

1970 ◽  
Vol 48 (9) ◽  
pp. 592-597 ◽  
Author(s):  
G. Norris Melville ◽  
W. T. Josenhans ◽  
W. T. Ulmer
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Water Loss ◽  
Healthy Subjects ◽  
Airway Resistance ◽  
Tap Water ◽  
Distilled Water ◽  
Moist Air ◽  
Specific Airway Resistance ◽  
Water Elimination

Effects of increased water content of inspired air at 21–38 °C on specific airway resistance (sRaw) in 107 healthy subjects were measured with a body plethysmograph. Mean sRaw increased insignificantly at 23 °C with 92% relative humidity (water content, 20.7 g∙m−3) for up to 71 h but became significant at 6 h with water content 25 g∙m−3. Increases were greater when evaporated tap water was inhaled than when distilled water was used. It is postulated that the increase in sRaw is due to mucosal swelling and to contaminants in tap water. A theory of respiratory "water elimination" is proposed to replace the concept of respiratory water loss.

scholarly journals Some Aspects of Osmotic Regulation in Lampreys

1956 ◽  
Vol 33 (2) ◽  
pp. 431-447 ◽  
Author(s):  
M. W. HARDISTY
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Sea Water ◽  
Tap Water ◽  
Total Concentration ◽  
The Body ◽  
Unit Body Weight ◽  
Lampetra Planeri ◽  
The Mean ◽  
Osmolar Concentration

1. The mean osmolar concentration (expressed as mM. NaCl/1.) of the serum for Lampetra planeri was found to be 110 mM. in the ammocoete and 113 mM. in the adult. For adult L. fluviatilis serum in November the mean osmolar concentration was 143 mM. and in March 136 mM. 2. In adult planeri the Cl concentration of the body fluids accounted for nearly 90% of the total concentration as compared with only 58% in the serum of the ammocoete. Adult fluviatilis kept in tap water throughout the winter appeared to show an increase in Cl levels. 3. Evidence has been produced to support the view that the differences observed in water, fat and Cl content of ammocoete and adult planeri and adult fluviatilis are consequences of the period of starvation preceding sexual maturity. 4. Pronounced seasonal variations have been found in the fat and Cl content of ammocoetes of planeri. 5. The osmotic uptake of water has been determined for adults of both species in fresh water. In planeri the rate of uptake for unit body weight is about four times as great as in fluviatilis. 6. Observations have also been made on the osmotic loss of water of ammocoete and adult planeri and of adult fluviatilis in sea water of different concentrations. For unit body weight osmotic loss of water in planeri is about twice that of fluviatilis. 7. Total losses of Cl have been determined for ammocoete and adult planeri in distilled water and their effects on internal Cl levels have been studied. Observations have also been made on the active uptake of Cl. 8. Acclimatization experiments on ammocoetes and adult planeri and on adult fluviatilis have failed to produce any evidence of regulation in sea water.

Influence of Learning on Taste Preferences

1966 ◽  
Vol 19 (2) ◽  
pp. 445-446 ◽  
Author(s):  
Paul Thomas Young
Keyword(s):  
Tap Water ◽  
Taste Preferences ◽  
Distilled Water

Further discussion of the Schnorr and Brookshire study of the preference between distilled water and tap water, with comments and suggestions.

The Water Relations of Earthworms

1956 ◽  
Vol 33 (1) ◽  
pp. 29-44 ◽  
Author(s):  
BETTY I. ROOTS
Keyword(s):  
Body Weight ◽  
Water Content ◽  
Water Relations ◽  
Filter Paper ◽  
Tap Water ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Glass Tubes ◽  
Allolobophora Chlorotica

1. The water content of Lumbricus terrestris, after keeping on moist filter-paper for 3 or 4 days, is 84.8% of its body weight. That of Allolobophora chlorotica is 80% of its body weight. Both species can survive a loss of 60% of the body weight, but not much more. 2. Earthworms of the species A. chlorotica, A. terrestris f. longa, Dendrobaena subrubicunda, L. rubellus and L. terrestris are all able to survive from 31 to 50 weeks in soil totally submerged beneath aerated water. The same species, and A. caliginosa can survive for 72-137 days in aerated tap water without food. 3. Garden specimens of A. chlorotica make U-shaped burrows in soil beneath water. They do not irrigate either the burrows or glass tubes. Egg-cocoons of A. chlorotica, taken from culture pots of soil, will hatch under water and the young worms will feed and grow though totally immersed.

scholarly journals Hydraulic Conductivity of Compacted Lime-Softening Sludge Used as Landfill Liners

2019 ◽  
Vol 230 (12) ◽  
Author(s):  
Agnieszka Dąbska
Keyword(s):  
Hydraulic Conductivity ◽  
Moisture Content ◽  
Tap Water ◽  
Distilled Water ◽  
Landfill Liners ◽  
Water Permeation ◽  
Lime Softening ◽  
Approximate Polynomial ◽  
Hazardous Waste Landfills

AbstractThe research goal was to investigate the hydraulic conductivity of compacted lime-softening sludge as a material to be applied to landfill liners. In doing so, the effect of compaction and moulding moisture content on the sludge hydraulic conductivity was assessed. An approximate polynomial k10mean at hydraulic gradients ≥30 for degree of compaction (0.95–1.05) and moulding moisture content (28%–36%) was determined. The results of short-term tap water permeation tests revealed that all hydraulic conductivity values were less than 2.5•10–8 m/s. A lowest hydraulic conductivity of 6.5•10–9 m/s, as well as a corresponding moisture content of 31% were then established. The long-term hydraulic conductivity was measured with tap water, distilled water, NaOH and HCl solutions and municipal waste leachate. The factors of permeating liquids and permeation time significantly affected the initial hydraulic conductivity. The long-term hydraulic conductivity increased for NaOH and HCl solutions and decreased for tap and distilled water. A significant reduction of hydraulic conductivity was observed for leachate permeation. The investigated material met the requirements for the liner systems of inert landfill sites regardless of pH and the limit value for hazardous and non-hazardous waste landfills.

Evaluation of Millipore Cartridge-type Water Treatment Systems for Microbiological Applications

1979 ◽  
Vol 42 (8) ◽  
pp. 654-655 ◽  
Author(s):  
BARBARA L. GREEN ◽  
WARREN LITSKY
Keyword(s):  
Water Treatment ◽  
Produced Water ◽  
Tap Water ◽  
Ionic Species ◽  
Distilled Water ◽  
Microbiology Laboratory ◽  
Type Water ◽  
Control Water ◽  
Q System

Two different cartridge-type water treatment systems were evaluated for use in the microbiology laboratory, employing the Distilled Water Suitability Test (DWST). The Milli-Q system fed by distilled water and the Milli-R/Q system fed by tap water both produced water acceptable for microbiological use as measured by the DWST. Concentrations of ionic species (as measured by conductivity) in Milli-Q and Milli-R/Q products were significantly lower than in the double distilled control water.

INFLUENCE OF ORGANIC MATTER ON THE GERMICIDAL EFFICIENCY OF QUATERNARY AMMONIUM AND HYPOCHLORITE COMPOUNDS

1948 ◽  
Vol 26f (2) ◽  
pp. 91-104 ◽  
Author(s):  
C. K. Johns
Keyword(s):  
Staphylococcus Aureus ◽  
Organic Matter ◽  
Quaternary Ammonium ◽  
Tap Water ◽  
Skim Milk ◽  
Distilled Water ◽  
Water Solutions ◽  
E Coli ◽  
Test Organisms ◽  
High Concentrations

Using Staphylococcus aureus and Eschericha coli as test organisms, the influence of various concentrations of skim milk on the germicidal potency of Roccal and of Dalglish hypochlorite solutions was studied. Both germicides retained their activity in the presence of unexpectedly high concentrations of skim milk, especially against S. aureus. Small concentrations frequently showed a slight potentiating effect in both laboratory and plant tests. The effectiveness of the hypochlorite fell off sharply beyond a certain concentration, while that of Roccal declined more gradually. Solutions of Roccal prepared with tap water were decidedly less active against E. coli than those prepared with distilled water. With the hypochlorite, tap water solutions were equally effective. Against S. aureus, a similar difference was noted although to a lesser extent. Added skim milk depressed the germicidal action of tap water solutions of Roccal to a greater extent than for distilled water solutions, while for the hypochlorite the reverse held true.

Effects of Water Quality and Spray Volume on Glyphosate Phytotoxicity

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 38-41 ◽  
Author(s):  
P. W. Stahlman ◽  
W. M. Phillips
Keyword(s):  
Water Quality ◽  
Tap Water ◽  
Herbicidal Activity ◽  
Inorganic Salts ◽  
Distilled Water ◽  
Volume Activity ◽  
Spray Solution ◽  
Spray Volume ◽  
Test Plants ◽  
Effective Carrier

Several inorganic salts added to the spray solution reduced the herbicidal activity of glyphosate [N-(phosphonomethyl)glycine]. Of the salts tested, iron and aluminum reduced herbicidal activity most. Reductions by calcium and zinc were moderately severe; by magnesium, moderate; by potassium and sodium, none. The reduction in phytotoxicity seems to be caused by cations, but factors other than valence also may be involved.Reduction in phytotoxicity was related to salt concentration and spray volume. Glyphosate at 0.84 kg/ha in 93 to 374 L/ha distilled water killed test plants. Tap water was an equally effective carrier at 93 and 187 L/ha volumes, but was significantly less effective at the 374 L/ha volume. Activity decreased as the molar concentration of CaCl2 increased to 0.01. Herbicidal activity was eliminated at 0.01 M and 374 L/ha; however, concentrations of CaCl2 exceeding 0.04 M reversed the trend and reacted similarly to a 0.005 M solution, which approximates the minimum hardness of most ground waters in Kansas.

scholarly journals Experiments on Freeze-Bonding Between Ice Blocks in Floating Ice rubble

1986 ◽  
Vol 32 (112) ◽  
pp. 397-403 ◽  
Author(s):  
R. Ettema ◽  
J.A. Schaefer
Keyword(s):  
Tap Water ◽  
Contact Period ◽  
Distilled Water ◽  
River Waters ◽  
Air Temperatures ◽  
Strength Behavior ◽  
Series Of Experiments ◽  
Bond Strengths ◽  
Saline Solutions ◽  
Thick Layers

AbstractSeries of experiments were conducted with the aim of determining the influences of the following factors on freeze-bonding between contacting ice blocks in floating ice rubble: pressure normal to the contact plane, period and area of contact, and salinity of the water in which freeze-bonding occurred. Freeze-bonding between ice blocks in air was also investigated. The experiments were conducted with water and air temperatures of about 0°C and normal pressures, between ice blocks, up to 4 kPa. This range of normal pressures may occur hydrostatically between ice blocks in layers of floating ice rubble up to about 10 m thick, or in 2-3 m thick layers which are in a passive Rankine state of pressure. The experiments show that stronger freeze-bonds develop between ice blocks in distilled water, tap water, and water from the Iowa River than develop between ice blocks contacting in air at 0°C. However, stronger freeze-bonds developed in air at 0°C than developed between ice blocks in 0°C saline (NaCl) solutions with salinities in excess of 12.5% by weight. The strength of freeze-bonding increased linearly with contact period for ice blocks in distilled, tap, and river waters, but did not increase with contact period for ice blocks contacting in saline solutions or in air. The results of the experiments are useful contributions to explanations of the shear-strength behavior of a layer of floating ice rubble. For example, thicker layers of ice rubble may show greater cohesive behavior, because normal pressures and thus freeze-bond strengths increase with layer thickness.

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