The comparative effects of exchangeable calcium, magnesium, and sodium on some physical properties of red-brown earth subsoils. III. The permeability of Shepparton soil and comparison of methods

Soil Research ◽  
1973 ◽  
Vol 11 (2) ◽  
pp. 159 ◽  
Author(s):  
AC Bakker ◽  
WW Emerson
Keyword(s):  
Flow Rate ◽  
Divalent Cation ◽  
Magnesium Chloride ◽  
Aggregate Stability ◽  
Viscous Drag ◽  
Comparison Of Methods ◽  
Soluble Salts ◽  
Initial Flow ◽  
Calcium Magnesium ◽  
Water Transmission

Beds of aggregates of Shepparton soil were leached with calcium chloride or magnesium chloride or with chloride solutions of given SAR with either calcium or magnesium as the complementary cation to bring the aggregates to a known ESP within the range 2.6-5.2. The last solution was 1 mM in the divalent cation. Water was then allowed to flow slowly through and the decrease in the flow rate measured. The permeability of aggregate beds washed with calcium or magnesium showed only a negligible decrease with time. With sodium present, the rate of decrease for a given ESP was faster the greater the initial flow rate of the water and also for smallersized aggregates. The ESP required to produce a given decrease in flow rate was reduced when magnesium was the complementary cation rather than calcium. The flow patterns are explained in terms of the rate of dispersion of clay from the aggregates in sympathy with the rate of loss of soluble salts, rather than detachment due to viscous drag. Four methods of measuring aggregate stability in water have been described in this series of papers. Their possible use to predict whether sodium in conjunction with magnesium will reduce water transmission through subsoils compared with similar calcium soils is discussed.

ABOLITION OF MAGNESIUM-INDUCED HYPOCALCAEMIA BY ACUTE THYRO-PARATHYROIDECTOMY IN THE CAT

1970 ◽  
Vol 64 (1) ◽  
pp. 150-158 ◽  
Author(s):  
S. Pors Nielsen
Keyword(s):  
Sodium Chloride ◽  
Flow Rate ◽  
Magnesium Chloride ◽  
Calcium Concentration ◽  
Plasma Calcium ◽  
Magnesium Concentration ◽  
Isotonic Sodium Chloride ◽  
Plasma Calcium Concentration ◽  
High Concentrations ◽  
Plasma Magnesium

ABSTRACT Intravenous infusion of isotonic magnesium chloride into young cats with a resultant mean plasma magnesium concentration of 7.7 meq./100 g protein was followed by a significant lowering of the plasma calcium concentration in 90 minutes. The rate of decrease of plasma calcium is consistent with the hypothesis that calcitonin is released by magnesium in high concentrations. There was no decrease in the plasma calcium concentration in cats of the same weight thyroparathyroidectomized 60 min before an identical magnesium chloride infusion or an infusion of isotonic sodium chloride at the same flow rate. The hypercalciuric effect of magnesium could not account for the hypocalcaemic effect of magnesium. Plasma magnesium concentration during magnesium infusion into cats with an intact thyroid-parathyroid gland complex was slightly, but not significantly higher than in acutely thyroparathyroidectomized cats.

The Cost-Benefit of Pulse-Oximeter Use in the Prehospital Environment

1999 ◽  
Vol 14 (4) ◽  
pp. 41-46 ◽  
Author(s):  
Andrew J. Macnab ◽  
Lark Susak ◽  
Faith A. Gagnon ◽  
Janet Alred ◽  
Charles Sun
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Flow Rate ◽  
Cost Savings ◽  
Cost Benefit ◽  
Standard Protocol ◽  
Clinical Value ◽  
Transport Time ◽  
Initial Flow ◽  
Flow Rates

AbstractIntroduction:Pulse-oximetry has proven clinical value in Emergency Departments and Intensive Care Units. In the prehospital environment, oxygen is given routinely in many situations. It was hypothesized that the use of pulse oximeters in the prehospital setting would provide a measurable cost-benefit by reducing the amount of oxygen used.Methods:This was a prospective study conducted at 12 ambulance stations (average transport times >20 minutes). Standard care protocols and paramedic assessments were used to determine which patients received oxygen and the initial flow rate used. Pulse-oximetry measurements (oxygen-saturation measured by pulse oximetry) were then taken. If oxygen-saturation measured by pulse oximetry fell below 92% or rose above 96% (except in patients with chest pain), oxygen (O2) flow rates were adjusted. Costs of oxygen use were calculated: volume that would have been used based on initial flow rate; and volume actually used based on actual flow rates and transport time.Methods:A total of 1,907 patients were recruited. Oximetry and complete data were obtained on 1,787 (94%). Of these, 1,329 (74%) received O2 by standard protocol: 389 (27.5%) had the O2 flow decreased; 52 had it discontinued. Eighty-seven patients (6%) not requiring O2 standard protocol were hypoxemic (oxygen-saturation measured by pulse oximetry < 92%) by oximetry, and 71 patients (5%) receiving oxygen required flow rate increases. Overall, O2 consumption was reduced by 26% resulting in a cost-savings of $0.20 / patient. Prehospital pulse-oximetry allows unncessary or excessive oxygen therapy to be avoided in up to 55% of patients transported by ambulance and can help to identify suboptimally oxygenated patients (11%).Conclusion:Rationalizing the O2 administration using pulse-oximetry reduced O2 consumption. Other health care savings likely would result from a reduced incidence of suboptimal oxygenation. Oxygen cost-saving justifies oximeter purchase for each ambulance annually where patient volume exceeds 1,750, less frequently for lower call volumes, or in those services where the mean transport time is less than the 23 minute average noted in this study.

Characteristics Analysis of SCWR During Partial Loss of Reactor Coolant Flow Transient

2012 ◽  
Author(s):  
Juan Chen ◽  
Tao Zhou ◽  
Zhousen Hou ◽  
Canhui Sun
Keyword(s):  
Flow Rate ◽  
Transient Analysis ◽  
Coolant Flow ◽  
Partial Loss ◽  
Initial Flow ◽  
Reactor Coolant ◽  
Loss Of Coolant ◽  
Characteristics Analysis ◽  
And Control ◽  
Supercritical Water Cooled Reactor

Partial loss of reactor coolant flow is one of the most important transients for safety analysis of supercritical water-cooled reactor (SCWR). Taking the super LWR concept provided by Japan as research object, transient analysis of partial loss of coolant flow rate is given by coupled neutronics and thermal hydraulics calculation method. The results show that, when 5% partial loss of coolant flow is happening, maximum cladding temperature would increase firstly with the decreasing of fuel channel inlet coolant flow. Then followed with the neutronic feedback and control operation, maximum cladding temperature decreases and finally return to normal. When 50% partial loss of coolant flow is happening, a scram signal will be given to ensure system safety, but the maximum cladding temperature still shows a significant increase early. On this basis, sensitivity analysis is performed considering the influence of core power and main coolant flow. It is found that maximum peaking value increases significantly following the initial flow rate decreasing, but shows a very little increase caused by core power increasing.

scholarly journals Excretion by the Malpighian Tubules of the Stick Insect, Dixippus Morosus (Orthoptera, Phasmidae): Calcium, Magnesium, Chloride, Phosphate and Hydrogen Ions

1956 ◽  
Vol 33 (4) ◽  
pp. 697-708
Author(s):  
J. A. RAMSAY
Keyword(s):  
General Problem ◽  
Magnesium Chloride ◽  
Liquid Paraffin ◽  
Stick Insect ◽  
Urine Flow ◽  
Malpighian Tubules ◽  
Hydrogen Ions ◽  
Calcium Magnesium

1. The excretion of calcium, magnesium, chloride, phosphate and hydrogen ions has been studied in preparations of single Malpighian tubules isolated in drops of serum under liquid paraffin. 2. The concentrations of calcium, magnesium and chloride are always lower in the urine than in the serum. 3. The concentration of phosphate is always greater in the urine than in the serum. As the concentration of phosphate in the serum increases, the rate of urine flow also increases. 4. The urine is always alkaline to the serum but becomes acid in the rectum. 5. The general problem of excretion by Malpighian tubules is briefly reviewed and discussed.

scholarly journals SENSIBILIDADE DE GOTEJADORES À OBSTRUÇÃO POR PARTÍCULAS DE AREIA

Irriga ◽  
2018 ◽  
Vol 23 (2) ◽  
pp. 194-203
Author(s):  
Acácio Perboni ◽  
José Antonio Frizzone ◽  
Rubens Duarte Coelho ◽  
Rogério Lavanholi ◽  
Ezequiel Saretta
Keyword(s):  
Turbulent Flow ◽  
Flow Rate ◽  
Flow Regimes ◽  
Solid Particles ◽  
Automated System ◽  
Particle Sizes ◽  
Initial Flow ◽  
Water Flow Velocity ◽  
Sand Particles ◽  
Micro Irrigation

SENSIBILIDADE DE GOTEJADORES À OBSTRUÇÃO POR PARTÍCULAS DE AREIA     ACÁCIO PERBONI1; JOSÉ ANTONIO FRIZZONE2; RUBENS DUARTE COELHO2; ROGÉRIO LAVANHOLI3 E EZEQUIEL SARETTA4   1 Professor, IFMT, Campo Novo do Parecis - MT, [email protected] 2 Professor, Departamento de Engenharia de Biossistemas, ESALQ/USP, Piracicaba - SP, [email protected]; [email protected] 3 Doutorando, Departamento de Engenharia de Biossistemas, ESALQ/USP, Piracicaba - SP, [email protected] 4 Professor, UFSM, Cachoeira do Sul - RS, [email protected]     1 RESUMO   O objetivo deste trabalho foi avaliar a influência do tamanho e concentração de partículas de areia e da velocidade de fluxo da água nas linhas na sensibilidade à obstrução de um modelo de gotejador do tipo cilíndrico, não regulado, com vazão nominal de 2 L h-1. Foram realizados ensaios de obstrução com areia misturada em água destilada, combinando os seguintes fatores: três faixas granulométricas de partículas de areia, três concentrações de areia e três velocidades de fluxo de água no tubo. A vazão de 32 gotejadores foi medida a cada doze minutos por meio de um sistema automatizado. Nos ensaios com faixa granulométrica de 0,105 a 0,25 mm, ocorreu a obstrução nas concentrações de 250 e 500 mg L-1, para os regimes de escoamento de transição e turbulento. Já na faixa granulométrica de 0,25 a 0,5 mm, ocorreu obstrução nas concentrações de 100, 250 e 500 mg L-1, para os regimes de escoamento de transição e turbulento. A obstrução de gotejadores ocorreu de forma aleatória nas oito linhas. Após obstruídos os gotejadores não desobstruíram com o passar do tempo de ensaio.   Palavras-chave: microirrigação, partículas sólidas inertes, granulometria, concentração     PERBONI, A.; FRIZZONE, J. A.; COELHO, R. D.; LAVANHOLI, R.; SARETTA, E. SENSITIVITY OF DRIPPERS TO CLOGGING CAUSED BY SAND PARTICLES     2 ABSTRACT   The purpose of this research was to assess the influence of concentration and size of sand particles, and water flow velocity in laterals on the sensitivity of drippers to clogging. A cylindrical integrated non-pressure compensating dripper of 2 L h-1 nominal flow rate was used. Experiments were undertaken using distilled water and sand particles, according to the following levels: (a) three ranges of particles sizes; (b) three concentrations of particles; and, (c) three flow velocities in the laterals. The flow rate of 32 drippers was measured at every 12 minutes by an automated system. Within the range of particle sizes from 0.105 to 0.25 mm, clogging of emitters was observed under transient and turbulent flow regimes, and under particles concentration of 250 and 500 mg L-1. Within the range of particles sizes from 0.25 to 0.5 mm, clogging was observed for all concentrations under transient and turbulent flow regimes. Clogging of emitters occurred as a random phenomenon. Once clogged, emitters did not recover their initial flow rate.    Keywords: micro irrigation, inert solid particles, particle size, concentration

Induction of potential for sperm motility by bicarbonate and pH in rainbow trout and chum salmon

1988 ◽  
Vol 136 (1) ◽  
pp. 13-22 ◽  
Author(s):  
S. Morisawa ◽  
M. Morisawa
Keyword(s):  
Rainbow Trout ◽  
Seminal Plasma ◽  
Magnesium Chloride ◽  
Chum Salmon ◽  
Ph Value ◽  
Bicarbonate Concentration ◽  
Sodium Potassium ◽  
Sperm Duct ◽  
Calcium Magnesium ◽  
Immotile Spermatozoa

Spermatozoa of rainbow trout and chum salmon, which have no potential for motility in the testis, acquire that potential in the sperm duct. This paper demonstrates that there is little difference between the levels of sodium, potassium, calcium, magnesium, chloride and osmolality of the seminal plasma in the testis and in the sperm duct. However, the bicarbonate concentration of the seminal plasma and the pH value of semen were higher in the sperm duct than in the testis. When immotile spermatozoa obtained from the testis were incubated in artificial seminal plasma with a high pH and containing HCO3-, spermatozoa became motile within 1 h. These results suggest that spermatozoa of salmonid fish acquire the potential for motility as a result of the increase in seminal bicarbonate concentration and pH that occurs as spermatozoa pass from the testis to the sperm duct.

Zeolite/Cerium Oxide Coat-on Activated Alumina Ball for Arsenite Removal via Fixed- Bed Continuous Flow Adsorption Column

2021 ◽  
Author(s):  
Suttikorn Suwannatrai ◽  
Dickson Y. S. Yan ◽  
Pummarin Khamdahsag ◽  
Visanu Tanboonchuy
Keyword(s):  
Cerium Oxide ◽  
Flow Rate ◽  
Continuous Flow ◽  
Human Life ◽  
Fixed Bed ◽  
Point Of Zero Charge ◽  
Contaminated Water ◽  
Activated Alumina ◽  
Initial Flow ◽  
Alumina Ball

Arsenite (As(III)) has threatened human life for ages. It is a necessity to remove As(III) from the contaminated water before general use. With the improvement of adsorption, higher As(III) removal can be achieved. This study aimed to develop zeolite/cerium oxide coat-on activated alumina ball adsorbent (CeZ-ball) with the aid of PVA binder and apply it to a fixed-bed continuous flow column for As(III) adsorption. The coating percentage of CeZ-ball was studied. Cerium ions leaching from CeZ-ball were monitored throughout the 2,880-min-column run to confirm the stability of CeZ attached to an activated alumina ball. Surface area, pH point of zero charge, and structural property of CeZ-ball were characterized. An average CeZ coating of 83.3% and rare leaching of cerium proved the coating method. The models proposed by Yoon-Nelson provided the most satisfactory fit with the breakthrough curve (r2 = 0.985, MPSD = 2.547, and q0 = 3.481 mg·g–1) under experimental conditions of the flow rate of 5 mL·min–1, As(III) influent concentration of 1 mg·L–1, and CeZ-ball weight of 40 g. The half-time of breakthrough (τ) was 1,228.739 min. The effects of the key parameters, including initial adsorbent weight, initial flow rate, and initial As(III) concentration, were investigated for the performance of As(III) adsorption. Simulated from the Yoon-Nelson model, the τ increased as well as the adsorbent weight but decreased as the flow rate increased, thus impacting the As(III) concentration. With the optimal condition, the fixed-bed continuous column with CeZ-ball could be used in As(III) removal from contaminated water.

Secretion of K and fluid by rat submaxillary during sympathetic nerve stimulation

1975 ◽  
Vol 229 (4) ◽  
pp. 1056-1061 ◽  
Author(s):  
LH Schneyer
Keyword(s):  
Steady Flow ◽  
Flow Rate ◽  
Sympathetic Innervation ◽  
Stimulus Frequency ◽  
Submaxillary Gland ◽  
Pulse Frequency ◽  
Initial Flow ◽  
Saliva Secretion ◽  
High Concentrations ◽  
Two Phases

Stimulation of the sympathetic innervation to rat submaxillary gland is known to evoke saliva which contains high concentrations of potassium (130-160 meq/liter). Relationships were examined between salivary [K] and several parameters of the stimulation, including pulse frequency and duration of the stimulus train and rate of flow of the evoked saliva. Secretion of sympathetically evoked saliva was found to occur in two phases. After stimulation was started, flow rate was relatively high initially, and then decreased to a lower, relatively steady value. Initial and steady flow rates were maximal when stimulus frequency was 10 Hz. Salivary [K] was lowest initially, and, at that time, was inversely related to flow rate. At steady flow, [K] was flow independent. While salivary [K] was lower during initial than during steady secretion, the rate of K secretion was initially higher. During the initial phase, K decreased in the gland, and this decrease was sufficient to account for the increased amount of K secreted in initial saliva and for the increased initial flow.

Initial Flow Rate Relationships to Decline Trends and Reserves

2020 ◽  
Author(s):  
Brent Hale ◽  
Brent Hale ◽  
Amanda Warren ◽  
Russell Hall ◽  
William Cobb
Keyword(s):  
Flow Rate ◽  
Initial Flow
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