Showing papers on "Water flow published in 1969"

A structural basis for fluid secretion by malpighian tubules.

Abstract: The Malpighian tubules of Calliphora are described, emphasizing the possible role of surface specializations in solute-linked water transport. The tubules are composed of two cell types, primary and stellate, intermingling along the tubule length. The primary cells have long narrow basal infoldings and a microvillate luminal border, both intimately associated with mitochondria. The stellate cells have shorter and wider basal infoldings and their apical microvilli do not contain mitochondria. Application of the standing gradient hypothesis to this sytem provides a model for urine formation in which the local gradients for osmotic water flow occur within the long narrow channels of the basal infolds and microvilli of the primary cells. Stellate cells may modify the initial secretion by reabsorbing sodium.

Adaptive Changes of the Water Permeability of the Teleostean Gill Epithelium in Relation to External Salinity

Abstract: 1. Cannulation of afferent and efferent branchial vessels in the eel permitted studies of tritiated water clearance. It was observed that most of the diffusional water flow occurs through the gills. 2. Diffusional and osmotic water flows have been measured in a fresh-water ( Carassius ), a marine ( Serranus ) stenohaline fish and in two euryhaline species ( Platichthys and Anguilla ) adapted to either fresh water or sea water, and are found to be lower than in any comparable epithelia so far studied. 3. The diffusional water flow deduced from THO turnover is significantly smaller in the sea-water fish. 4. The osmotic water flow, determined indirectly by measuring drinking rate and urine flow, is smaller in the sea-water fishes despite a greater osmotic gradient across the gills. 5. Attempts to compare diffusional and osmotic permeabilities for the gill are hindered by our ignorance of the extent of solute (salt)-solvent interaction in the epitheium. It is suggested that the gill of the fresh-water-adapted fishes is semi permeable, while that of the sea-water teleosts may not be, because of the very high ionic exchange across the gill. 6. The surprisingly low diffusional and osmotic permeabilities of the gill epithelium in sea-water fish may be possibly related to the absence of water-filled pores.

The cellular specificity of the effect of vasopressin on toad urinary bladder.

Abstract: Phase and electron micrographs of toad bladders were obtained following dilution of bathing media in the presence and absence of vasopressin. Dilution of the mucosal medium alone resulted in no morphologic changes. Subsequent addition of vasopressin produced an increase in the cell volume of the granular cells, manifested by some or all of the following changes: increased area of granular cell profiles as observed in sections, rounding of the cell nucleus, displacement of the two components of the nuclear envelope, loss of nuclear heterochromatin, sacculation of the endoplasmic reticulum and the Golgi apparatus, and reduction in the electron density of the cell cytoplasm. No such morphologic changes were noted in the other cell types comprising the mucosal epithelium — the mitochondria-rich, the goblet, and the basal cells. On the other hand, dilution of the serosal bathing medium in the absence of vasopressin caused a marked increase in the cell volume of all these cell types. The results demonstrate that the action of vasopressin to enhance bulk water flow across toad bladder is exerted specifically on the apical surface of the granular cells. It is suggested that the hormonal effect on sodium transport may also be limited to the granular cells. The route of osmotic water flow and the possible role of the other mucosal epithelial cells is discussed.

The mechanism of salt and water absorption in the intestine of the eel (Anguilla anguilla) adapted to waters of various salinities

Abstract: 1. The absorption of NaCl and water was studied by intraluminal in vivo perfusion of the intestine of the yellow European eel (Anguilla anguilla) adapted to fresh water (FW), to sea water (SW), and to double strength SW (DSW).2. The net lumen to plasma NaCl transport from diluted SW perfusion fluids was independent of the NaCl concentration in the Na(+) concentration range tested. The NaCl absorption (expressed as mu-equiv/100 g.hr.) increased from FW (mean +/- S.E.): Na(+) 166 +/- 17, Cl(-) 205 +/- 24 to SW: Na(+) 363 +/- 33, Cl(-) 423 +/- 37, and again in DSW: Na(+) 640 +/- 110, Cl(-) 676 +/- 149.3. The osmolality of the perfusion fluid which resulted in zero net water transport was higher than plasma osmolality by 73 +/- 3 m-osmole in FW, 126 +/- 5 m-osmole in SW, and 244 +/- 32 m-osmole in DSW (mean +/- S.E.). A fairly constant ratio between net NaCl transport and this osmolality difference prevailed.4. The general osmotic permeability to water in the serosa-mucosa direction (expressed as mul./100 g. hr. m-osmole) measured from experiments with impermeant solute increased from FW: 3.7 +/- 0.5 to SW: 7.2 +/- 1.0 (mean +/- S.E.).5. These results are compatible with the interpretation that the water flow occurring in the absence of a general transmural osmotic gradient, the ;solute-linked water flow', is linearly related both to net NaCl transport and to the osmotic permeability to water. The findings support the view that the ;solute-linked water flow' is, indeed, secondary to the salt movement and is due to osmotic force.6. The amount of water absorbed from dilute SW perfusion fluids isosmotic with plasma was larger than in most other intestinal epithelia. FW: 650, SW: 1620 mul./100 g. hr. The NaCl concentration of the absorbate was hypertonic to plasma.7. The passive permeability of the intestine to NaCl was very low, and the reflexion coefficient was close to unity. Therefore metabolic energy will be used to absorb NaCl, even when the NaCl concentration in the gut is higher than that of plasma due to ingestion of SW. There appears to be a limited interaction in the intestinal wall between passive salt and water flow.8. In DSW the Na(+) ingestion with the oral intake of the surrounding fluid matched the gut absorption capacity. Since DSW is close to the tolerance limit, it is concluded that the gut NaCl transport capacity may be one of the factors limiting the tolerance to water or higher salinity.

Geophysical studies of water leakages from reservoirs

Abstract: Considerable water leakages from reservoirs make it difficult to attain the planned storage capacity. In some cases water leakages give rise to suffusion followed by catastrophes. Until recently methods for locating water leakages were extremely imperfect. Geophysical methods offer good prospects in this direction. For solving these problems, it is effective to use streaming potential measurements, water flow rate observations and thermometry. Laboratory experiments were carried out in connection with the fact that water leakages from reservoirs are characterized by negative anomalies of natural currents; the more filtration discharge, the higher these anomalies are. As a result, the relationship governing the intensity of streaming potential and sand granulometric composition, electrolyte concentrations and other factors were revealed. To determine the velocity of water flowing to leakage sites, a special device, based on the relationship between the temperature of a heated body and its resistance, is applied. This device simultaneously makes it possible to measure the water medium temperature. Observations at reservoir sites were effected by moving along the reservoir non-polarizable potential electrodes and water velocity devices. Recordings were carried out automatically by the recording device of the logging apparatus. Under the conditions of ice cover on water surfaces, measurements were made through separate points by digging holes in the ice cover. Practical field observations were carried out at reservoir sites located in regions where fissured massive rocks as well as loose sediments predominate. In the first case field experiments were carried out in alpine reservoirs, in Armenia. The major water leakages were found to be concentrated on the right bank of the reservoir. In this connection it was not only possible to locate water leakage sites, but also to evaluate their relative intensity. These data were used for planning antifiltration measures. In the second case water leakages from a reservoir located in Uzbekistan in the submontane part of the Pamirs were studied. Streaming potential anomalies and high benthonic flow rates made it possible to discover high filtrations in the base and walls of the dam. Further perfection of these methods should not only permit the determination of water leakage sites and their relative intensity, but also filtration discharges in absolute units.

Evaporation rate of water from the precorneal tear film and cornea in the rabbit

Abstract: A technique for the study of evaporation from the precorneal and cornea! surfaces has been developed. Evaporation from the superficial lipid layer (SLL) has been measured to be 10.1 x 10~ 7 Gm.cm.^secr 1 When this lipid layer is removed, evaporation increases around fourfold. Evaporation from the dry epithelial surface occurs at a rate of 1.8 x JO" 7 Gm.cmr^secr 1 After the epithelium is removed, a twentyfold increase in evaporation rate occurs. The specific resistances (u) to evaporation of these layers have been calculated: epithelium, = 82.5 sec./ cm.; SLL, = 12.9 sec/cm.; aqueous tears, < 1 sec/cm.; stroma, < 0 sec/cm. Thus, the superficial lipid layer is effective in retarding evaporation of the precorneal tear film. Its effectiveness compares favorably to that of condensed monolayers of long-chain fatty alcohols on pure water, known to be efficient in retarding evaporation. The epithelium functions as a barrier to water flow and is highly effective in retarding evaporation in the absence of a tear film.

The Effect of Amphotericin B on the Water and Nonelectrolyte Permeability of Thin Lipid Membranes

Abstract: This paper reports the effects of amphotericin B, a polyene antibiotic, on the water and nonelectrolyte permeability of optically black, thin lipid membranes formed from sheep red blood cell lipids dissolved in decane. The permeability coefficients for the diffusion of water and nonelectrolytes (PDDi) were estimated from unidirectional tracer fluxes when net water flow (Jw) was zero. Alternatively, an osmotic water permeability coefficient (Pf) was computed from Jw when the two aqueous phases contained unequal solute concentrations. In the absence of amphotericin B, when the membrane solutions contained equimolar amounts of cholesterol and phospholipid, Pf was 22.9 ± 4.6 µsec-1 and PDDHDH2O was 10.8 ± 2.4 µsec-1. Furthermore, PDDi was < 0.05 µsec-1 for urea, glycerol, ribose, arabinose, glucose, and sucrose, and σi, the reflection coefficient of each of these solutes was one. When amphotericin B (10-6 M) was present in the aqueous phases and the membrane solutions contained equimolar amounts of cholesterol and phospholipid, PDDHDH2O was 18.1 ± 2.4 µsec-1; Pf was 549 ± 143 µsec-1 when glucose, sucrose, and raffinose were the aqueous solutes. Concomitantly, PDDi varied inversely, and σi directly, with the effective hydrodynamic radii of the solutes tested. These polyene-dependent phenomena required the presence of cholesterol in the membrane solutions. These data were analyzed in terms of restricted diffusion and filtration through uniform right circular cylinders, and were compatible with the hypothesis that the interactions of amphotericin B with membrane-bound cholesterol result in the formation of pores whose equivalent radii are in the range 7 to 10.5 A.

The Distribution of PO2 and Hydrostatic Pressure Changes Within the Branchial Chambers in Relation to GILL VENTILATION OF THE SHORE CRAB CARCINUS MAENAS L

Abstract: 1. A technique is described for replacing part of the branchiostegite of Carcinus maenas by a transparent plastic ‘window’ for direct observation of the gills in situ with minimum disturbance. 2. Observation of dye streams shows that most water enters the hypobranchial space through the Milne-Edwards openings above the chelae, flowing anteriorly and/or posteriorly to ventilate most of gills 3-8. Water also enters above the pereiopods to ventilate the rest of the gills. Water passes from the hypobranchial to the epibranchial space, confirming that there is a counterflow with respect to the circulation of blood through the gill lamellae. 3. By sampling water at different points in the branchial system, patterns of oxygen removal were studied. The gradients confirmed the direction of water flow observed by the use of dyes. 4. Rhythmic changes in hydrostatic pressure in normal forward-pumping of 3-12 mm. H2O were recorded from the branchial cavities, superimposed on a maintained negative pressure relative to that outside the crab of 0-10 mm. H2O. Reversals produced a brief positive pressure change of 0-22 mm. H2O. 5. The possible relationships of the rhythmic pressure changes to scaphognathite movements are discussed. 6. The role of reversals is discussed and it is concluded that their primary function during ventilation is in helping to clean the ventrally facing gill surfaces. But they are also important in respiration under certain special conditions which arise during the normal life of the animal. 7. The utilization of O2 during its passage over the gills is low (7-23%) in spite of the counterflow. Possible explanations of this are discussed in relation to a model of the whole ventilation system.

Effects of sodium concentration and osmolality on water and electrolyte absorption from the intact human colon

Abstract: The influence of sodium concentration and osmolality on net water and monovalent electrolyte absorption from or secretion into the intact human colon was studied in healthy volunteers. WHEN ISOTONIC SOLUTIONS CONTAINING NACL AND/OR MANNITOL WERE INFUSED INTO THE COLON: (a) a direct linear relationship between luminal sodium concentration (in the range of 23-150 mEq/liter) and rate of net water, sodium, and chloride absorption was found. No water absorption was found when sodium concentration in the luminal fluid was below 20 mEq/liter; (b) water and sodium absorption from the isotonic test solutions was not enhanced by addition of 80-250 mg/100 ml of glucose; and (c) the rate of water and sodium absorption was decreased markedly when chloride was replaced by bicarbonate in the test solution. WHEN THE COLON WAS PERFUSED WITH HYPERTONIC TEST SOLUTIONS CONTAINING NACL AND MANNITOL OR UREA: (a) water was absorbed from hypertonic NaCl solutions against a lumen-to-blood osmotic gradient of 50 mOsm/kg; (b) when the osmolality of the mannitol solution was increased, water entered the colonic lumen at a more rapid rate. The relationship between the rate of water entering the colon and the osmolality of the test solution was a parabolic one; (c) sodium and chloride entered the colonic lumen at a rate that was lineraly related to that of water entrance when the lumen-to-blood osmotic gradient exceeded 150 mOsm/kg; (d) water flow into the colonic lumen was identical when equimolar urea or mannitol solutions were infused; (e) neither urea nor mannitol was absorbed in significant amounts from the hypertonic solutions; and (f) our results suggest that the equivalent pore radius of the human colon is smaller than the molecular radius of urea (2.3 A).

Paths of transtubular water flow in isolated renal collecting tubules.

Abstract: The cells of perfused rabbit collecting tubules swell and the intercellular spaces widen during osmotic flow of water from lumen to bath induced by antidiuretic hormone (ADH). Ouabain had no influence on these changes. In the absence of net water flow intercellular width was unaffected when tubules were swollen in hypotonic external media. Therefore, during ADH-induced flow widening of intercellular spaces is not a consequence of osmotic swelling of a closed intercellular compartment containing trapped solutes, but rather is due to flow of solution through the channel. Direct evidence of intercellular flow was obtained. Nonperfused tubules swollen in hypotonic media were reimmersed in isotonic solution with resultant entry of water into intercellular spaces. The widened spaces gradually collapsed completely. Spaces enlarged in this manner could be emptied more rapidly by increasing the transtubular hydrostatic pressure difference. In electron micrographs a path of exit of sufficient width to accommodate the observed rate of fluid flow was seen at the base of the intercellular channel. It is concluded that the intercellular spaces communicate with the external extracellular fluid and that water, having entered the cells across the luminal plasma membrane in response in ADH, leaves the cells by osmosis across both the lateral and basilar surface membranes.

Indicator dilution measurements of extravascular water in the lungs

Abstract: Multiple indicator dilution studies of the pulmonary circulation were carried out in conscious, resting and exercising, and anesthetized dogs under conditions where there was no pulmonary edema. Labeled red cells, water, and albumin were injected together into the pulmonary artery, and effluent dilution patterns were obtained from the descending thoracic aorta. The product of the mean transit time differences between labeled water and red cells, and the pulmonary water flow was used to estimate extravascular parenchymatous water; and this was expressed as a proportion of the water content of the blood-drained lung at postmortem examination. These estimates of the proportional water content were found to increase with flow, and to approach an asymptotic value. Reconsideration of the flow patterns in capillaries, however, led to the postulate that extravascular water should be calculated, utilizing as the appropriate vascular reference a substance that uniformly labels the water in red cells and plasma, and which is confined to the circulation, rather than a tracer that only labels red cells. The mean transit time of this substance is approximated by the sum of the mean transit times of labeled red cells and albumin, each weighted according to the proportion of the water content of blood present in that phase. The values for lung water content so computed also increased with flow, and appeared to approach an asymptote that corresponded to approximately two-thirds of the wet lung weight. The estimated values for the water space after pentobarbital anesthesia corresponded to the lower values obtained in the resting conscious animals. When the anesthetized animals were also bled, the estimated water space was disproportionately large, in relation to the previous values. These experimental results support the hypothesis that dilutional estimates of the lung water space reflect pulmonary capillary filling; that this filling increases with exercise; and that a relative increase in filling also occurs as part of the response to hemorrhage.

One-dimensional equations of open-channel flow

Abstract: One-dimensional equations of continuity, momentum, and energy for unsteady, spatially varied flow in a fixed-bed open channel of arbitrary configuration are derived from the point forms of the corresponding hydrodynamic equations by integrating the latter over a deforming region of space comprising a slice of differential thickness across the flow with a top always coincident with the fluctuating water surface. To bring the equations to the form of Saint Venant in fixed and accelerating reference frames, departures from hydrostatic pressure conditions in a cross section due to lateral acceleration, viscous deformation, and turbulent Reynolds stresses are reproduced exactly; the rate of energy dissipation in a cross section is uniquely related to wall shear over the wetted perimeter; the term accounting for lateral discharge depends upon its nature; bulk outflow is considered.

An estimate of the salt concentration in the lateral intercellular spaces of rabbit gall-bladder during maximal fluid transport.

Abstract: The ability of the gall-bladder to transport water between identical bathing solutions depends on active NaCl transport, which is thought to maintain the salt concentration in the lateral intercellular spaces above bathing solution levels and thus to create a local osmotic gradient. The mean value of this gradient has been estimated by an electrical procedure, based on measuring the small diffusion potential resulting from this gradient and from the preferential cation permeability of the gall-bladder. The electrical potential difference (p.d.) in maximally transporting rabbit gall-bladders is 1.4 mV, mucosal-solution positive to serosal solution. This p. d. is reversibly abolished or greatly reduced by six procedures which abolish or greatly reduce fluid transport (low temperature, replacement of Cl− by SO4--, replacement of Cl− and HCO3− by SO4--, replacement of Na+ by choline, removal of HCO3−, and metabolic poisoning). The p. d. is increased by symmetrical partial replacement of NaCl by sucrose, which is expected to increase the salt concentration gradient between the lateral spaces and the bathing solutions. Since the transport mechanism of the gall-bladder is a neutral NaCl pump that cannot produce a p. d. directly, it is concluded that the observed p. d. is the expected diffusion potential. From this diffusion potential and from the measured value of a diffusion potential resulting from a known NaCl concentration gradient, the mean concentration of NaCl in the lateral spaces is calculated to be of the order of 10mm above the bathing solution value. Comparison of the external osmotic gradient required to stop water flow with the p. d. recorded under this condition of zero flow supports the validity of interpreting the p.d. in this fashion as a measure of the excess local salt concentration.

Effect of Adrenal steroid hormones on the response of the toad's urinary bladder to vasopressin

Abstract: This study was designed to examine the effect of adrenal steroid hormones on the response of the toad bladder to vasopressin. Aldosterone enhanced the short-circuit current response, the osmotic water flow response, and the urea permeability response to vasopressin. Since aldosterone also enhanced the short-circuit current response and the osmotic water flow response to adenosine 3',5'-monophosphate, the steroid effect on the bladder's response to vasopressin appears to be at a step beyond the stimulation of adenyl cyclase. Indirect evidence was obtained that the effect of adrenal steroid hormones on the osmotic water flow response to vasopressin is mediated by a different hormone-tissue interaction than that mediating the effect of adrenal steroid hormones on sodium transport. In experiments with three different pairs of mineralocorticoid and glucocorticoid analogues, the former had a greater effect on short-circuit current, the latter on the osmotic water flow response to vasopressin. In addition, the spirolactone SC-14266 markedly inhibited the short-circuit current effect of dexamethasone and had little or no inhibitory effect on the dexamethasone enhancement of the osmotic water flow response to vasopressin. Aldosterone and dexamethasone stimulate the oxidation by the bladder of glucose-6-(14)C and depress the rate of oxidation of glucose-1-(14)C compared with glucose-6-(14)C. SC-14266 inhibited the effect of dexamethasone on the oxidation of glucose-6-(14)C but did not alter the effect of the steroid on the rate of oxidation of glucose-1-(14)C compared with glucose-6-(14)C, suggesting that the latter is a glucocorticoid effect and the stimulation of glucose-6-(14)C oxidation a mineralocorticoid effect. Under conditions in which aldosterone has produced a marked enhancement of short-circuit current and the permeability response to vasopressin, the steroid had no detectable effect on cell water content or on cell sodium, potassium, or chloride.

Resistance to water flow in soil and plant

Abstract: Summary Two experiments described in an earlier paper, on the transpiration rates of root-pruned and unpruned wheat plants at various soil moisture contents, are discussed with the aid of further data. The matric potential drop across the rhizosphere, and the relative magnitude of the rhizo-sphere and plant resistances are calculated for the unpruned plants at various soil matric potentials. Even at −15 bars soil matric potential the estimated drop was only 0.02 bar, and the rhizosphere resistance was less than 2% of the plant resistance. The amount of water made available to the plant by root extension was only a small fraction of that lost by transpiration. We suggest that root interception is unlikely to be important in the field, as long as new roots are growing among existing ones. Reasons are considered for the declining influence of root pruning on transpiration as the soil dried. It can be partly explained by the soil resistance remaining very small and by the relationship between transpiration rate and leaf water potential. However, there was evidently some other factor involved, possibly change in plant resistance or influence of root kinins on transpiration rate. The effects of root pruning on transpiration are too complex to provide satisfactory evidence on the magnitude of the rhizosphere resistance, but the experimental results are at any rate in agreement with the calculated prediction that it remained very small.

Contributions of unstirred-layer effects to apparent electrokinetic phenomena in the gall-bladder

Abstract: Passage of electric current across rabbit gall-bladder, which is preferentially permeable to cations, causes water flow towards the negative electrode, as expected for electroosmosis in a cation-selective membrane. Current passage also causes development of a “polarization potential difference”, i.e. a transepithelial potential difference (p.d.) which transiently remains after cessation of current flow and decays back to zero with a half-time of 22 to 90 sec. The polarization p.d. is due to current-induced local changes of salt concentration in unstirred layers, mainly at the serosal face of the epithelium. These changes originate through the so-called transport-number effect. Calculation shows that much of the observed current-induced water flow represents an osmotic flow due to these local concentration changes, rather than representing true electroosmosis. By implication, a large component of streaming potentials in the gall-bladder is a boundary diffusion potential, owing to water flow producing local changes of salt concentration in unstirred layers.

Definitive Computation of Sand Discharge in Rivers

Abstract: A procedure for an analytic determination of sand discharge in streams is presented especially adaptable to computer programming, requiring only a modicum of input or given data from which the sand discharge fractions are both separately and in combination completely described quantitatively and in distribution from bed to water surface. It has been tested by application and comparison with observed data in all types of rivers, small to large, under a full range of flow conditions, and to model flume experiments conducted under widely varying flow conditions with bed sands varying widely in size and size distribution. It is considered that the results by this procedure are sufficiently accurate to warrant its use in many types of studies involving quantitative sand transport, design of channels, channel regulation works, and the assessment of probable effects of channel modifications.

Behavior and Physical Factors Causing Migration and Aggregation of the Sand Crab Emerita Analoga (Stimpson)

Abstract: Migration and distribution of Emerita on sand beaches can be explained in terms of water flow and a simple behavioral response. Wash zones of sand beaches are bounded burrow out of fluid sand and so are kept within the boundaries of the wave wash. As the position of a wash zone is shifted with the tide, Emerita are carried in it to new locations on the beach. Lateral flow within the wave wash distributes Emerita into clumps along the shore. See full-text article at JSTOR

Nonlinear Flow in Porous Media by Finite Elements

Abstract: Two commonly suggested forms of the equation linking head loss and velocity for flow of water through coarse granular media are the Forchheimer and exponential relations. Combined with the continuity expression, these relations give the differential equations applicable, within the limits of validity of the parent relations, to actual regions of flow. The resultant nonlinear partial differential equations are amenable to solution by the numerical technique known as the method of finite elements. This technique has advantages when dealing with complex boundary shapes. Solutions have been obtained for some examples of unconfined flow with boundary conditions similar to those likely to be encountered in practical applications. Experimental work in an open flume has shown that agreement between observed and calculated values of discharge and piezometric head can be obtained when the coefficients in the head loss equations are accurately known.

Biologically Significant Properties of Submerged Marine Sands

Abstract: The distribution of Branchiostoma lanceolatum does not appear to be related to the texture of the sand in which it lives At Helgoland there is a great variety of different sands some of which contain large numbers of lancelets and others few or none In contrast at Le Racou on the south coast of France the same species is present in varying numbers in apparently uniform sands It does not seem that coarseness of the deposit is in itself a limiting factor but rather that the animals react to some more subtle properties The nature of these properties in Helgoland and Le Racou sands has been investigated A system of sieves has been used to separate the sand grains into grades in which the ratio between the diameters of the smallest and largest grains in each grade approximates to 1: 15 An estimate of the error involved in grading sands is given A formula is suggested for determining grain surface area (specific surface) that takes account of differences in grain shape A new falling head permeameter is described in which consolidation of the sand is induced by placing the sand column in an ultrasonic wave field and controlled by the length of exposure to the radiation Measurements of porosity and the rate of flow of water (drainage factor) through a sand column are obtained at different degrees of compaction from loose to close packing of the grains and are closely replicable A linear relationship between porosity and drainage factor has been found to exist for the whole or part of the process of consolidation and appears to be due to the maintenance of grain orientation in the sand grain lattice during compression until (if it happens) a sudden reorientation of the grains takes place and a new lattice with a different geometry is formed Sands are thus recognized to have single-phase, two-phase or three-phase consolidation according to the number of such changes in the geometry of the lattice As the rate of change in drainage factor with porosity is constant within a phase of consolidation, this ratio, here called the specific permeability, can be used to compare the different phases in different sands without complications arising from differences in degree of compaction It has been demonstrated that B lanceolatum and also the interstitial harpacticoid copepod, Evansula incerta, both react not only to differences in specific permeability but also to differences in that part of the void that changes with the drainage factor and has been called the capillary space Capillary space is envisaged as pathways through the sand of preferential flow, the remainder of the void being relatively stagnant and termed cavity space Specific permeability is thought to represent the relative rate at which capillary water can be exchanged with water above the sand Capillary space changes continuously with consolidation, whereas cavity space is constant for a given phase in consolidation, but changes with the phase Porosity, specific permeability and cavity and capillary space have been measured first in graded sands at temperatures from 5 to 30 degrees C and then in various simple mixtures of two grades at 20 degrees C Except for porosity which is temperature independent, changes in temperature and, for the mixtures, small changes in composition caused fluctuating and often relatively large changes in these characteristics of a nature that would have been difficult to predict The fluctuations appear to have been due first to differential effects of changes in fluidity on the rates of flow of water through pores of different size and, secondly, to alterations in the form of the sand grain lattice brought about by changes in the composition of the mixtures so small as to be barely recognizable if at all by sieving Experiments with sands on which epipsammic films of bacteria have been grown by irrigating the sand with nutrient solution have shown that their properties are highly modified by the extent and thickness of the film which evidently changes the adhesiveness of the grains and hence the geometry of the lattice they form Any factor that determines organic content should modify the properties of sands from this cause In addition, stratification in a sand arising from differences in deposition or from the activity of burrowing animals also affects the spatial and flow characteristics Thus sand deposits of similar particle size composition but with different non-random in situ arrangements of grains and differences in their organic component, neither being characters that appear in grain-size analysis, may differ in their properties from place to place and seasonally and may support different faunas both in numbers and species Moreover, the capillary characteristics of sands, being measured with a permeameter using a standard water flow, only have meaning in an irrigated sand Such characteristics cannot exist in sands in which there is no movement of water but appear as soon as forces operate that cause interstitial flow such as pressure differences due to animal activity, wave movement and convection The biologically important conditions in a natural sand deposit depend in part on the magnitude of the forces that cause irrigation and therefore cannot properly be estimated without information on the water movements in its neighbourhood both in the short and in the long term

Foam injection test in the Siggins Field, Illinois

Abstract: The feasibility of injecting foam into a reservoir was investigated at the Siggins field in 2 phases between Oct. 1964 and June 1967. The purposes of the field test were to determine: (1) the effectiveness of foam in reducing gas and water flow in a reservoir; and (2) the best means of handling foam under reservoir conditions. In this test, foaming agent solutions and compressed air were injected into one well both alternately and simultaneously. Field production from 5 offset production wells was observed. For comparison, water and air were injected at similar operating conditions. The results showed that foam reduced both the mobility of gas and the mobility of water in the reservoir to less than 50% of their original values. Severe channeling of gas to one production well was stopped. Also, foam caused a more uniform water injection profile and reduced the average WOR of surrounding wells from 15 to 12 over a 2-yr period. (10 refs.)

Chemical Composition of Rainbow Trout Urine following Acute Hypoxic Stress

Abstract: Rainbow trout (Salmo gairdnerii) were anesthetized with MS-222, catheterized, and introduced into urine collecting chambers. Twenty-four hours after introduction, a 4-hour accumulation of urine was collected to serve as the control. Water flow to the chambers was then discontinued for 30 minutes during which the oxygen content of the water exiting in the chamber dropped from 4.9 to 2.8 mg/1. Following this hypoxic stress fresh water was restored and accumulated urine samples were taken for analysis at 1, 4, and 20 hours post-hypoxic stress. Rainbow trout excrete abnormally high concentrations of Na, K, Mg, Cl, and inorganic PO4 following hypoxia.

Kinetics of sorption and volume change in three-component systems

Abstract: The paper analyses one-dimensional absorption (swelling) and desorption (shrinkage) in media subject to volume change (such as soils of high colloid content) and containing both water and air. The void ratio, the hydraulic conductivity, and the moisture potential are taken to be arbitrary known functions of the volumetric moisture content e. Then the combination of Darcy's law, applied to water flow relative to the soil particles, and the continuity requirement yields the general flow equation for systems of this type. In terms of material coordinates, the equation takes a nonlinear heat-conduction form. For media exhibiting (a) zero and (b) normal volume change, the equation reduces, as it should, to two known equations: (a) the nonlinear diffusion equation in physical coordinates, and (b) the nonlinear diffusion equation in material coordinates. The specific problem is that of sorption consequent on a step-function change in moisture potential at the column surface. The column is taken to be effectively semi-infinite (and constrained at infinity). The relevant solution of the general flow equation is of the similarity formm(e,t) = o(e)t1/2 where m is the material coordinate, t is time, and 4(8) is found by the solution of a nonlinear, ordinary, integrodifferential equation. A rapid and accurate numerical method of evaluating o(e) from any given set of soil characteristics is provided by a minor variant of an established technique for solving the nonlinear diffusion equation subject to similar conditions. With o(e) known, it is an elementary matter to restate the solution in physical coordinates, and to deduce a great variety of properties of the sorption process : profiles of moisture content, moisture potential, and void ratio; cumulative total volume change and the instantaneous rate of total volume change; cumulative total sorption and the instantaneous sorption rate; profiles of soil-particle velocity; profiles of volume flux density of water (i) relative to the soil particles and (ii) due to mass flow; profiles of absolute volume flux density of water; and the displacement history of soil particles initially at various positions in the column. Two examples are worked out fully, one for absorption and one for the converse desorption process. Graphs are presented illustrating the various aspects of the solution mentioned above. It is found, in keeping with previous work on two-component systems exhibiting normal volume change, that swelling is propagated more rapidly than is shrinkage but that it is associated with a slower rate of exchange of water. As in the earlier study (Philip 1968), this seeming paradox arises from the influence of the mass flow of water on the phenomena. For the example of absorption, the total column swelling amounts to only 43% of normal swelling; on the other hand, the converse desorption process produces over 99% of normal shrinkage. The moisture profiles computed for absorption exhibit a shallow surface layer of large moisture gradient, reminiscent of the transition zone sometimes observed in infiltration and absorption experiments. The present analysis applies to the drying of a cracking soil, so long as the (properly defined) void ratio function exists.

Circular hydraulic jump

Abstract: Hydraulic jumps involving radial flow, as in diverging stilling basins, have not been properly analyzed. Dynamical considerations disclose that the radial flow jump involves a force not found in the rectangular jump. As a consequence, the sequent depth and energy loss for a radial jump are less and greater respectively than that for a rectangular jump. In addition, experimental findings indicate that the length of the radial jump is less than that of the rectangular jump.

An investigation of heat transfer in the liquid deficient regime.

Abstract: Heat transfer data were obtained for forced convection steam water flow in a 0.760'' O.D., 0.600'' I.D. annulus at pressures between 600 and 1200 psia and mass velocities up to 3.0 x 10 {sub 6} lbm/h.ft{sub 2}. A literature survey of stable film boiling heat transfer covered several fluids at a wide range of pressures and the existing theories on film boiling were reported. A variety of correlations was compared with the available world data. Three new correlations were developed - for tubes, annuli, and tubes and annuli combined. The RMS error was respectively 11.5%, 6.9% and 12.4%.

Physiological and morphological effects of poly- L -lysine on the toad bladder

Abstract: Studies were carried out on the morphological and physiological effects of the binding of poly-L-lysine (polylysine; mol wt≊120,000) to the apical surface membrane of the toad bladder epithelium. Paired hemibladders were mounted in chambers and exposed to polylysine concentrations of 2, 8, or 80 μg/ml in the mucosal medium for periods of up to 2 hr. Radioautographs prepared after addition of3H-polylysine showed that the polymer was localized to the apical surface of the epithelium and in dense subapical masses in lysed cells. No significant morphological changes were seen in the epithelium by light or electron microscopy at polymer concentrations of 2 and 8 μg/ml. Exposure to 80 μg/ml lysed many epithelial cells, i.e., converted them to slightly swollen ghosts with pycnotic nuclei and empty cytoplasm, except for remnants of mitochondria and vesicular fragments of the endoplasmic reticulum. All of the superficial epithelial cells were lysed in stretched hemibladders. The plasma membranes of the lysed cells were uniformly thickened, and their intercellular attachments remained intact. In contracted hemibladders, lysed and normal-appearing cells were interspersed, and the number of lysed cells in the epithelium was proportional to the duration of exposure to high concentrations of the polycation. In parallel experiments, the effects of varying concentrations of polylysine on active Na+ transport and osmotic flow of water were measured with and without vasopressin, aldosterone, or amphotericin B in the media. At a concentration of 2 μg/ml of polylysine in the mucosal bathing solutions, no change in the basal rate of Na+ transport was seen, and the response to vasopressin was unimpaired. At a concentration of 8 μg/ml, there was a significant but small fall in electrical potential difference (PD) and in short-circuit current (SCC) and no interference with the response to vasopressin. At a concentration of 80 μg/ml, there was a rapid curvilinear fall in SCC to 54±4% of the baseline value and in PD to 21±3% of the baseline value in a 2-hr period. Simultaneous unidirectional isotope flux studies with22Na and24Na showed a more than twofold increase in the serosal to mucosal flux but no discrepancy between net flux and SCC. Despite the inhibitory action of the polymer, the stimulatory response in Na+ transport to vasopressin, aldosterone, and amphotericin B was relatively preserved in that the percentage increase in SCC was the same in the polymer-treated and control hemibladders. The polycation produced a small but significant increase in osmotic water flow, and striking and irreversible inhibition of the water-flow response to vasopressin.