Showing papers on "Water flow published in 1974"
TL;DR: In this paper, the Strouhal number as a function of Reynolds number measured by Moller (1938) has been confirmed using water flow and the lower critical Reynolds number, first reported by Cometta (1957), was found to be Re = 6 × 103.
Abstract: Vortex shedding from spheres has been studied in the Reynolds number range 400 < Re < 5 × 106. At low Reynolds numbers, i.e. up to Re = 3 × 103, the values of the Strouhal number as a function of Reynolds number measured by Moller (1938) have been confirmed using water flow. The lower critical Reynolds number, first reported by Cometta (1957), was found to be Re = 6 × 103. Here a discontinuity in the relationship between the Strouhal and Reynolds numbers is obvious. From Re = 6 × 103 to Re = 3 × 105 strong periodic fluctuations in the wake flow were observed. Beyond the upper critical Reynolds number (Re = 3.7 × 105) periodic vortex shedding could not be detected by the present measurement techniques.The hot-wire measurements indicate that the signals recorded simultaneously at different positions on the 75° circle (normal to the flow) show a phase shift. Thus it appears that the vortex separation point rotates around the sphere. An attempt is made to interpret this experimental evidence.
477 citations
TL;DR: Under static conditions of no water flow, a change in water potential is expected over the distance between the soil and the leaves in the canopy of a tree, and under conditions where there is a flow of water through the soil-plant-atmosphere continuum, a larger difference is to be expected as the result of the resistances to flow encountered by the moving water.
Abstract: Under static conditions of no water flow, a change in water potential of about 0.1 bar m-' is expected over the distance between the soil and the leaves in the canopy of a tree. Under conditions where there is a flow of water through the soil-plant-atmosphere continuum, a larger difference in water potential is to be expected as the result of the resistances to flow encountered by the moving water. The magnitude of the depression of water potential in the leaves depends on both the resistances to flow through the soil-plant-atmosphere continuum and on the rate of flow which is determined by the atmospheric onditions at the leaves. In small herbaceous plants, the resistance of the plant itself to water movement is small (Tinklin & Weatherley 1966, 1968), and the major part of the plant resistance lies in the leaves and the roots, the contribution of the stem to the total being small (Jensen, Taylor & Wiebe 1961; Boyer 1971; Stoker & Weatherley 1971). Nonetheless, gradients in water potential of 5 bar m-' between roots and leaves have been reported under conditions of high evaporation (Begg & Turner 1970; Cary & Fisher 1971). (It should be noted that much of the literature showing low leaf water potentials in plants in the field, even in the leaves of plants growing in moist soil, is not relevant in this connection because of the likely occurrence of an appreciable resistance in the soil surrounding the roots, or at the root-soil interface (Tinklin & Weatherley 1968).) In larger plants, such as trees, it might be expected that the stem resistance would be sufficiently arge to contribute appreciably to the reduction in leaf water potential even under quite moderate conditions of evaporation and that differences in stem anatomy amongst species might be partly responsible for different reductions in leaf water potential. For example, Farmer (1918) showed that the resistance of coniferous hoots to the passage of water was three to six times that of broad-leaved trees, and Peel (1965) found a lower resistance to flow of water in the xylem of ring porous Fraxinus than in the xylem of diffuse porous Acer and Salix. The significance of this resistance in the stem to the development of low water potentials in the leaves depends on its size in relation to the total resistance in the soil-plant-atmosphere continuum. If it is relatively large, the implication is that low leaf water potentials may occur in tall trees largely as a result of the distance of the leaves from the source of water. Recently there has been some dispute as to whether the gradient of water potential in the stems of tall trees does in fact exceed that required to maintain the hydrostatic head, viz. 0 1 bar m-'. Gradients no steeper than this have been reported in tall trees of Sequoia sempervirens, Pseudotsuga menziesii and Sequoiadendron giganteum even at * Permanent address: Institute of Physiological Botany, University of Uppsala, Uppsala, Sweden.
316 citations
TL;DR: An in vivo perfusion of the intestine of the yellow European eel was used to measure the net absorption of NaCl and water, the osmotic permeability coefficient, the solute-linked water flow, and theOsmolality difference against which the intestine could transport water as functions of the salinity of the surrounding water.
Abstract: 1. An in vivo perfusion of the intestine of the yellow European eel ( Anguilla anguilla ) was used to measure the net absorption of NaCl and water, the osmotic permeability coefficient, the solute-linked water flow, and the osmolality difference against which the intestine could transport water as functions of the salinity of the surrounding water. The eels were adapted to fresh water, to sea water, and to 1½ strength sea water.
2. The osmolality difference against which the intestine could transport water was observed to be linearly related to the net transmural flow of NaCl; the solute-linked water flow had a constant hypertonicity in spite of differing net flows of NaCl. The findings are in agreement with the hypothesis of uphill water movement being caused by local osmosis due to the salt flow and with a shunt leak proportional to the transmural osmotic difference.
3. An important part of adaptation to waters of higher salinity is a pronounced increase in the intestinal absorption of NaCl.
4. The osmotic permeability coefficient varied from experiment to experiment without relation to the state of adaptation. An explanation for this finding may be that the osmotic permeability of the intestinal epithelium is of little importance for the total intestinal transfer of water.
114 citations
TL;DR: Multiple linearization is a convolution routing technique which allows variations in wave celerity and damping with discharge, from 10-50% gains in root mean square accuracy can be obtained when routing hourly discharge values.
Abstract: Multiple linearization is a convolution routing technique which allows variations in wave celerity and damping with discharge By treating the input to a routing reach as a set of inputs to several subsystems, rather than as a single system, from 10-50% gains in root mean square accuracy can be obtained when routing hourly discharge values Significant visual improvement in the arrival time of low flows is achieved Little gain in accuracy is possible when routing daily discharges unless 2-day or 3-day differences in arrival time occur
85 citations
TL;DR: Two responses to hypoxia were routinely observed: an initial hyperirrigation response maintained oxygen consumption by increased branchial water flow, and this response was not maintained, but oxygen consumption remained at pre-hypoxic levels while pumping rates decreased.
Abstract: 1. Changes in the rate and force of scaphognathite beating, irrigation volume, oxygen utilization, oxygen consumption and heart rate during acclimation in response to the experimental conditions and in response to long-term hypoxic exposure have been measured in the crayfish Orconectes virilis .
2. Immediately following placement in the experimental chamber the animals exhibited very high levels of respiratory and circulatory performance. These levels decreased slowly and stable minimal performance levels could be measured only after 2-3 days. A 3-day acclimation period under normoxic conditions thus routinely preceded hypoxic experiments to ensure measurement of unmasked hypoxic responses.
3. Two responses to hypoxia were routinely observed: an initial hyperirrigation response maintained oxygen consumption by increased branchial water flow. This response was not maintained, but oxygen consumption remained at pre-hypoxic levels while pumping rates decreased.
4. Possible mechanisms of acclimation to hypoxia are discussed.
82 citations
Patent•
07 Mar 1974
TL;DR: An automatic swimming pool cleaner comprised of a car adapted to travel underwater along a random path on the pool vessel surface for dislodging debris there from. as mentioned in this paper The car wheels are driven by a water powered turbine to propel the car in a forward direction, along the vessel surface.
Abstract: An automatic swimming pool cleaner comprised of a car adapted to travel underwater along a random path on the pool vessel surface for dislodging debris therefrom. The car wheels are driven by a water powered turbine to propel the car in a forward direction, along the vessel surface. In order to prevent the car from being driven into a position, as for example against a vertical wall, from which it cannot emerge, a wheel geometry is employed which, upon contact, develops a horizontal force component parallel to the vertical wall, to thus enable the car to spin off. Alternatively, or in combination, a water flow produced reaction force can produce a torque to turn the car with respect to the engaged wheel to enable the car to spin off. The car is designed with a low center of gravity and a relatively buoyant top portion so as to produce a torque which maintains the car correct side up when on the pool bottom. Means are provided on the car for producing a water flow having a force component perpendicular to the vessel surface to provide good traction between the car wheels and the vessel surface. Further, a water flow produced suction is created adjacent to the vessel surface for collecting debris into a basket carried by the car. In addition, one or more hoses is pulled by the car and whipped by water flow to sweep dirt from the vessel surface for collecting debris into a basket carried by the car.
80 citations
TL;DR: In this paper, the authors studied the effect of severe fluctuations in flow on the distribution of bottom fauna of the upper Kennebec River and found that slow currents resulting from low flows appeared to limit the diversity and abundance of swiftwater aquatic insects on the river-bottom below the dam.
Abstract: We studied the effect of severe fluctuations in flow on the distribution of bottom fauna of the upper Kennebec River. During the years 1964–1970, discharges below Wyman Dam ranged from 8.5 m3/sec to an average daily high of about 170 m3/sec. Slow currents resulting from low flows appeared to limit the diversity and abundance of swift-water aquatic insects on the river-bottom below the dam. Sampling stations above the impoundment averaged 19 aquatic insect genera, while those below the dam averaged 11. About 19 genera were found at stations where the current near bottom fluctuated from 0.5 m/sec to 0.9 m/sec while only 4 genera were found at stations where the fluctuations were from 0.1 to 0.5 m/sec. Aquatic insects adapted for swift water such as Rhyacophila, Chimarra, Iron, Blepharocera, Acroneuria, and Paragnetina were more abundant above the impoundment than below, and were absent from those stations below the impoundment with the lowest current velocities.
79 citations
TL;DR: Lake George, a shallow lake in western Uganda, supports a permanent and dense crop of phytoplankton, and may be regarded as eutrophic although the ambient concentrations of inorganic nitrogen and phosphorus are low.
Abstract: Lake George, a shallow lake in western Uganda, supports a permanent and dense crop of phytoplankton, and may be regarded as eutrophic although the ambient concentrations of inorganic nitrogen and phosphorus are low. The figures for the annual nutrient loadings (Viner and Smith, 1973) would suggest, however, a eutrophic lake when analysed on the scheme of eutrophication proposed by Vollenweider (1968). The horizontal distribution of chlorophyll a shows a concentric pattern, with the maximum values occurring towards the center. This horizontal variation is thought to reflect water movements, and a general pattern of water flow is proposed. The majority of the species show no seasonal variation but populations of both Anabaena and Melosira show annual variations. These two species also have a horizontal distribution pattern which is the reverse of other species. This pattern is used to support the proposed movements of water. Phytoplankton generation times are discussed in relation to the diurnal cycle occurring in Lake George.
77 citations
TL;DR: During 1966 and 1967, the spawning runs of an anadromous population of alewives, Alosa pseudoharengus (Wilson), were studied in Bride Lake, Connecticut and counts of the number of fish entering and leaving the lake indicated that high mortalities occurred.
Abstract: During 1966 and 1967, the spawning runs of an anadromous population of alewives, Alosa pseudoharengus (Wilson), were studied in Bride Lake, Connecticut. Alewives entered the lake from Long Island via Bride Brook from March to June. The number of fish entering the lake each day varied and was not related to water temperature or amount of moonlight. Males predominated among early migrants, whereas a 1:1 sex ratio existed through the later part of the migration. The average size of adults decreased as the migration progressed. Adults spent from several days to 3 months on the spawning grounds, the males outnumbering the females. Counts of the number of fish entering and leaving the lake indicated that high mortalities occurred. Females spawned from 48,000–360,000 eggs. The total number of eggs spawned in the lake was estimated to be 2.0 X 1010. Young alewives migrated seaward from June to October and increased water flow was thought to be a major stimulant. One young alewife migrated seaward for eve...
76 citations
TL;DR: In this paper, a two-layer model is constructed in order to describe water flow over an impermeable boundary, consisting of vertical flow through an unsaturated layer and flow along a boundary in a saturated layer.
Abstract: A two-layer model is constructed in order to describe water flow over an impermeable boundary. The model consists of vertical flow through an unsaturated layer and flow along a boundary in a saturated layer. The governing equations are solved for the nonsteady case, where the gradient of the thickness of the saturated layer is small compared with the slope of the impermeable boundary. It is shown that in most cases the discharge from shallow snowpacks will preserve the diurnal cycles of input at the surface, although for deep snowpacks (such as temperate glacier firn) the diurnal cycle is smoothed and only long-term responses are expected. The flow of a diurnal meltwater wave through a small (2.10 m deep by 100 m long) snowpack is calculated as an example. The case of steady flow is also described.
76 citations
TL;DR: Three of the most important advances in the field of water relations are acceptance of the term, water potential, to describe the free energy status of water in soil and plants, and marked improvement in methods of measuring water potential and stomatal resistance.
Abstract: Many of the basic concepts dealing with soil and plant water relationships were in existence 50 years ago, but were inadequately presented in the textbooks of that time. There has been a marked increase in the amount of work done in this field during recent decades, but much of it involves advances in understanding the concepts already in existence. Three of the most important advances in the field of water relations are: (a) acceptance of the term, water potential, to describe the free energy status of water in soil and plants; (b) marked improvement in methods of measuring water potential and stomatal resistance; and (c) use of the concept of water flow in the soil-plant system as analogous to flow of electricity in a conducting system.A number of interesting and important problems remain to be studied. Of these, probably the most important is to learn why mild water stress of less than - 10 bars can affect various enzyme-mediated metabolic processes. Plant scientists in applied fields also need to learn more about the causes of differences in ability to tolerate drought among plants of various kinds. There is uncertainty concerning the relative magnitude of the resistances to water flow in various parts of the soil-plant system and concerning the causes of the apparent changes in resistance to water flow with increase in rate and with time of day. More information also is needed concerning the role of growth regulators synthesized in roots and the importance of the older, suberized roots in the absorption of water and mineral nutrients.
TL;DR: Obs observations on young colonies of Membranipora reveal that the metamorphosing larvae were orientated with respect to the axis of the Sargassum leaflets, which is consistent with the view that tannins present in the young thallus inhibit the establishment of the surface microflora which is a pre-requisite for the settlement of larger epibionts.
TL;DR: In this article, the effects of air movement and compressibility during ponded infiltration were studied, and it was shown that if air cannot escape freely through the walls, there is a considerable reduction in the infiltration rate, the shape of the water profiles is significantly different and the air pressure gradients are not negligible.
Patent•
25 Feb 1974
TL;DR: In this paper, a boat amusement ride with a long downchute trough portion is provided as part of a boat boat ride, with a significant recovery in elevation following from the bottom of the down-chute portion.
Abstract: A long downchute trough portion is provided as part of a boat amusement ride with a significant recovery in elevation following from the bottom of the downchute portion. Water and passenger carrying boats ride over a common supportive bottom surface of the trough. A dam is provided at the top of the downchute portion to initially block water flow when the amusement ride is started. When enough water is accumulated behind the dam it is opened and the mass of water travels along the downchute and up the subsequent rise portion, thus ''''priming'''' the ride.
Patent•
05 Apr 1974
TL;DR: In this paper, vertical water wheels with collapsible blades are used instead of toothed belts for water current power generator systems, where the blades fold into a collapsed position as they pass over the rear roller and move in a direction opposite the water flow.
Abstract: A water current power generator system comprises one or more generator ships firmly anchored to the water bottom to generate power from sea currents or the tidal flow of rivers. The hull of a typical ship includes an inlet where the moving water enters and drives blades hinged to a toothed belt which moves about a pair of rollers. As the blades move about the forward roller, the hinged blades are driven outwardly to a right angle position to be driven by the water flow. The blades fold into a collapsed position as they pass over the rear roller and move in a direction opposite the water flow thereby minimizing resistance to the water flow. Generally, a pair of toothed belts are provided within each shaped inlet with a thrust member therebetween to direct the water towards the blades. The belts are mounted vertically within the hull to encounter as much of the water pressure as possible. The water then flows out the rear of the hull through a shaped outlet which is smaller than the inlet. In an alternate embodiment, vertical water wheels with collapsible blades are used instead of toothed belts. This variation would include at least one of such wheels positioned at the inlet and having hinged members serving as blades mounted on the wheels to catch the water flow thereby driving the wheel. The blade would then pivot to an open position minimizing resistance to the motion of the wheel as it moves around the axis of said wheel.
TL;DR: In this article, Peltier-cooled thermocouple dewpoint hygrometers were used to measure leaf water potentials at several transpiration rates on intact corn (Zea mays L.), soybean (Glycine max (L.) Merr.), and sunflower (Helianthus annus L.), grown in a controlled environment in silica sand rooting media frequently watered with nutrient solution.
Abstract: Peltier-cooled thermocouple dewpoint hygrometers were used to measure leaf water potentials at several transpiration rates on intact corn (Zea mays L.), soybean (Glycine max (L.) Merr.), and sunflower (Helianthus annus L.), grown in a controlled environment in silica sand rooting media frequently watered with nutrient solution. Hygrometers were left in position for the duration of measurements on each plant, but tests showed this to have little effect on measured potentials. Measured potentials were found to be linearly related to the transpiration rates (correlation coefficients greater than 0.98). Extrapolated values of leaf water potential at zero transpiration were within a few tenths bar of measured nutrient-solution potentials. These results indicated that plant resistances to water flow remained constant from near zero transpiration up to the maximum obtained average rates of 1.8–3.0 g dm−2 h−1. The magnitude of the resistance varied considerably from plant to plant even within a single cultivar of...
TL;DR: In this paper, a computer simulation of countercurrent CO 2 exchange in fish gills was constructed to examine effects of variations in blood and water flow rates, contrary to experimental data.
Abstract: 1. A computer simulation of countercurrent CO 2 exchange in fish gills was constructed to examine effects of variations in blood and water flow rates. 2. CO 2 output was sensitive to both blood and water flow rates, contrary to experimental data. 3. Various explanations of the contradiction are discussed, including patterns of gill perfusion and possible shunting of blood. 4. A simplified version of the model was also used to demonstrate extreme sensitivity of CO 2 efflux to variations of the residence time of blood in the gills. 5. Data from the literature on reaction rate constants for the CO 2 /carbonate/ bicarbonate system are summarized, and the importance of some of these reactions is examined.
TL;DR: In this paper, an experimental study of the air-entraining roller zone of hydraulic jumps in open channels was performed using hot-film anemometry techniques, involving instant digitizing of analog signals and delayed electronic processing of the tape-recorded data.
Abstract: Paper reports on an experimental study of the air-entraining roller zone of hydraulic jumps in open channels. Hot-film anemometry techniques were used, involving instant digitizing of analog signals and delayed electronic processing of the tape-recorded data. The two phases (air versus water) were identified by a signal threshold. Results are presented on void ratio and average size and statistical size distribution of the entrained air bubbles for jumps with and without fully developed inflow. Findings confirm that the state of flow development of the supercritical stream entering the jump has a significant bearing on the resulting flow configuration within the jump body and thus, on the air-entraining capacity of the hydraulic jumps.
TL;DR: Water flow within the branchial chamber, blood flow withinThe gill filaments, and the fine structure of the gill epithelium have been determined in the crayfish Procambarus clarkii and Morphological evidence suggests that gas exchange might occur in both directions.
Abstract: Water flow within the branchial chamber, blood flow within the gill filaments, and the fine structure of the gill epithelium have been determined in the crayfish Procambarus clarkii. The epithelium of the podobranch filaments, which is 3.15–8.70 μ thick, represents the blood-to-water diffusion distance. Blood flow within the filament is arranged in a bidirectional system that is first cocurrent and then countercurrent to the flow of water irrigating the gills. Morphological evidence suggests that gas exchange might occur in both directions. Shunting of blood occurs within the gill filament and its significance in countercurrent blood flow and gas exchange is discussed.
Patent•
29 Apr 1974
TL;DR: In this paper, the authors describe a transverse pivotable plates which have guide wheels which engage a set of guide rails at the outer end of the pivot plate, and the buckets are mounted on a conveyor belt which travels in an endless fashion.
Abstract: This apparatus relates to a device which converts water flow into electrical power. It is particularly adapted to be installed totally submerged in a body of water or at offshore locations. It intercepts tidal flow, oceanic currents and the like to generate power. It includes a framework enabling the apparatus to be installed on the bottom of a body of water. It incorporates a plurality of adjustable guide louvers which are positioned to direct a stream in a particular manner. The louvers cooperate with a generally flat transverse plate which extends fully across the equipment. The plate cooperates with the louvers to direct the stream of water to a point intercepting the set of buckets carried on a conveyor. The buckets are not of ordinary construction as found on water wheels, but are especially constructed to erect when intercepting water flow, which causes them to fill, and to collapse on a return passage. They are mounted on a conveyor belt which travels in endless fashion. The collapsing of the buckets on the return passage reduces water flow resistance and forces them to dump the water. The buckets are defined by transverse pivotable plates which have guide wheels which engage a set of guide rails at the outer end.
TL;DR: In conditions of alternating light and dark, juvenile Penaeus merguiensis de Man are more active during the dark phase and there is an irregular short-term rhythm, suggested that this allows starved prawns to conserve energy.
Abstract: In conditions of alternating light and dark, juvenile Penaeus merguiensis de Man are more active during the dark phase. The rhythm persists in continuous dim red light, but not in continuous bright white light. The period of circadian rhythm shown in continuous dim red light varies between individuals from 22.75 to 26.0 h, with a mean of 23.8 h. The response of prawns to an artificially produced tidal situation is mediated by the presence or absence of water flow. No endogenous component of this tidal rhythm was demonstrated. There is an irregular short-term rhythm (period 2 to 3 h). It is suggested that this allows starved prawns to conserve energy.
TL;DR: A numerical model for the simultaneous transport of anions and water as developed in Pt. 1 of this work was compared with measured chloride and water flow data in this paper under conditions of infiltration, redistribution, and evaporation of water in the upper part of the soil profile.
Abstract: A numerical model for the simultaneous transport of anions and water as developed in Pt. 1 of this work was compared with measured chloride and water flow data. Laboratory soil-column experiments were conducted under conditions of infiltration, redistribution, and evaporation of water in the upper part of the soil profile. The effects of convection, ionic diffusion, mechanical dispersion, anion exclusion, and water flow in response to salt concentration gradients on the comparison between numerical and measured data were considered jointly. (11 refs.)
TL;DR: Bulk water transport in reconstituted ghosts is statistically comparable to that in the parent red cells, and is unaffected by incorporation of Ca 2+ over the range of 0.01 to 1 mM, and recovery of normal impermeability to choline, sucrose, Na + and inulin is demonstrated.
TL;DR: In this paper, nine-year-old Cox's Orange Pippin apple trees in a hedgerow-type orchard were deprived of water, by using a soil cover to intercept rainfall, from late March until mid-June, 1973.
Abstract: SummaryNine-year-old Cox’s Orange Pippin apple trees in a hedgerow-type orchard were deprived of water, by using a soil cover to intercept rainfall, from late March until mid-June, 1973. Trees in adjacent rows received normal rainfall and other trees were given supplementary irrigation. Total plant water potential was monitored by means of a pressure bomb, soil water status was assessed by gypsum resistance blocks, and various micrometeorological parameters were measured.Fruit-set was considerably reduced by plant water stress, and in addition the trees with minimal water stress retained more fruits per cluster than the droughted ones.Interactions between soil water status and evaporative demand, and the effects of these factors on plant water status, were demonstrated, and these have been interpreted within a theoretical framework. Plant impedance values, calculated on the basis of the theory presented, indicate that resistance to water flow through the plant may not be a constant.
TL;DR: A minimum storage convolution scheme is presented whereby the diffusion analogy or Harley routing models may be applied with desktop computers to reduce the required storage for matrix convolution.
Abstract: A minimum storage convolution scheme is presented whereby the diffusion analogy or Harley routing models may be applied with desktop computers. The technique reduces the required storage for matrix convolution from (n² + nj + j + n - 1) to 2n, in which n is the number of response function ordinates and j is the number of input values. An extension of the technique may be used for multiple linearization routing.
TL;DR: Ethacrynic acid is an antagonist of antidiuretic hormone and probably occurs at the level of the receptor site of the hormone on the peritubular membrane, which may be one of the factors involved in the loss of renal concentrating ability brought about by ethacryic acid diuresis.
Abstract: Effects of the diuretic ethacrynic acid on osmotic water permeability were investigated in the isolated perfused collecting tubule of the rabbit kidney. The base-line water permeability of the collecting tubule was not affected when the drug (10(-4)M) alone was added to the bathing medium. Vasopressin alone in the bathing medium (2, 5 muU/ml) elicited a significant increase in osmotic water absorption. With vasopressin kept in the bathing medium, the addition of 10(-5)M ethacrynic acid depressed the hydro-osmotic effect of vasopressin by 50%. This inhibitory effect of low concentrations of ethacrynic acid could be surmounted by high, supramaximal dosage levels of vasopressin. When 10(-4)M ethacrynic acid was added to the bathing medium before vasopressin, the hydro-osmotic effect of vasopressin and the diuretic in combination was insignificant.Dibutyryl adenosine 3'5'-monophosphate (10(-4)-10(-2)M) alone in the bathing medium significantly increased baseline osmotic water flow, mimicing the effect of antidiuretic hormone. When ethacrynic acid was added together with the nucleotide, the permeability remained at the same high level. Theophylline, like the nucleotide and vasopressin, produced a significant hydro-osmotic effect. The magnitude of this response was not affected by further addition of ethacrynic acid (10(-4)M). It was concluded that ethacrynic acid is an antagonist of antidiuretic hormone. The antagonism probably occurs at the level of the receptor site of the hormone on the peritubular membrane. Antagonism to circulating antidiuretic hormone may therefore be one of the factors involved in the loss of renal concentrating ability brought about by ethacrynic acid diuresis.
Patent•
06 Sep 1974
TL;DR: In this article, the rear ski and a jet pump are secured as an integral unit to an engine and the exhaust and cooling systems are arranged to eliminate flooding despite location of portions of the engine below water when the craft is at rest.
Abstract: A jet powered watercraft of motorcycle-like configuration. Longitudinally aligned front and rear skis are located in spaced relation below a hull and operate to hydrodynamically lift the watercraft to a cruise position by relative water flow upon the undersides of the skis. The rear ski and a jet pump are secured as an integral unit to an engine. The rear ski includes an opening through which water passes to the jet pump, and further includes channels on either side of the opening to collect and carry away entrained air. The engine is located in the hull and is cooled by water supplied by the jet pump which it drives. The front ski is rotatable for steering and is resiliently extensible for stability in turning. The center of buoyancy of the watercraft is above its center of gravity so that the craft is self-righting. The exhaust and cooling systems are arranged to eliminate flooding despite location of portions of the engine below water when the craft is at rest. The jet pump discharge nozzle is completely out of the water in the cruise position of the craft for maximum thrust.
01 Feb 1974
TL;DR: In this paper, a model of the atmosphere-plant-soil moisture relations on a day-to-day basis is described, and a computer program of the model is listed.
Abstract: lates atmosphere-plant-soil moisture relations on a day-to-day basis. The model is explained in detail, and a computer program of the model is listed. Computer output resulting from an application of PROSPER to a forested watershed is also presented. (auth)
Patent•
17 Oct 1974
TL;DR: In this article, an approach for separation of particulate matter from a gas flow by interacting the gas flow with a water curtain within a contacting chamber is described, where the gas flows enter the contacting chamber tangentially near the bottom thereof whereby it tends to spiral upwardly toward an exhaust opening at the top of the chamber.
Abstract: Apparatus is disclosed for achieving separation of particulate matter from a gas flow by interacting the gas flow with a water curtain within a contacting chamber. The gas flow enters the contacting chamber tangentially near the bottom thereof whereby it tends to spiral upwardly toward an exhaust opening at the top of the chamber. Means are provided to form a water curtain across the passage through which the gas flow enters the chamber whereby particulate matter such as dust carried in the gas flow is entrained by water droplets thereof. Above the area of the gas flow inlet passage, spaced-apart ring-like members are provided for disrupting the upwardly spiraling gas flow and forcing the flow away from the chamber's side wall. A chamber rinsing means is provided adjacent the upper end of the chamber for directing a rinsing water flow downwardly against the chamber side wall in a spiral flow countercurrent to the gas flow. Still another water inlet means may be provided at a central location in the chamber above the level of the gas inlet passage to direct a downward axial water spray in the direction of the lower end of the chamber. The chamber has a discharge opening at its lower end for discharging water with the collected particulate matter separated from the gas flow.