The Extracellular Bicarbonate Concentration and the Regulation of Ventilation in Chronic Hypercapnia in Man

1974 ◽  
pp. 273-281
Author(s):  
Gerard M. Turino ◽  
Roberta M. Goldring ◽  
Henry O. Heinemann
Keyword(s):  
Bicarbonate Concentration

The Effects of Carbonate-Bicarbonate Concentration on Empirical Corrosion Diagram of Mild Steel as a Material of Geological Disposal Package for High Level Nuclear Wastes

1996 ◽  
Vol 451 ◽  
Author(s):  
Guen Nakayama ◽  
Yuichi Fukaya ◽  
Masatsune Akashi
Keyword(s):  
Mild Steel ◽  
Human Life ◽  
General Corrosion ◽  
Nuclear Wastes ◽  
Bicarbonate Concentration ◽  
Sulfate Ions ◽  
Geological Disposal ◽  
Groundwater Environment ◽  
High Level ◽  
Corrosion Diagram

ABSTRACTIn the scheme for geological disposal of high level radioactive nuclear wastes, the burial pit is to be isolated from the sphere of human life by a multiple-barrier system, which consists of an artificial barrier, composed of a canister, an overpack and a bentonite cushioning layer, and a natural barrier, which is essentially the bedrock. As the greatest as well as essentially the sole detriment to its integrity would be corrosion by groundwater. The groundwater comes to it seeping through the bentonite zone, thereby attaining conceivably the pH of transition from general corrosion to passivity, pHd, the behaviors of mild steel in such a groundwater environment have been examined. It has been shown that the pHd is lowered (enlargement of the passivity domain) with rising temperature and carbonate-bicarbonate concentration, while it is raised (enlargement of the general corrosion region) with increasing concentrations of chloride and sulfate ions.

Reliability and Effect of Sodium Bicarbonate: Buffering and 2000-m Rowing Performance

2012 ◽  
Vol 7 (2) ◽  
pp. 152-160 ◽  
Author(s):  
Amelia J. Carr ◽  
Gary J. Slater ◽  
Christopher J. Gore ◽  
Brian Dawson ◽  
Louise M. Burke
Keyword(s):  
Calcium Carbonate ◽  
Confidence Interval ◽  
Sodium Bicarbonate ◽  
Pairwise Comparisons ◽  
Bicarbonate Concentration ◽  
Mean Power ◽  
Typical Error ◽  
Rowing Performance ◽  
Rowing Ergometer ◽  
Double Blinded

Purpose:The aim of this study was to determine the effect and reliability of acute and chronic sodium bicarbonate ingestion for 2000-m rowing ergometer performance (watts) and blood bicarbonate concentration [HCO3−].Methods:In a crossover study, 7 well-trained rowers performed paired 2000-m rowing ergometer trials under 3 double-blinded conditions: (1) 0.3 grams per kilogram of body mass (g/kg BM) acute bicarbonate; (2) 0.5 g/kg BM daily chronic bicarbonate for 3 d; and (3) calcium carbonate placebo, in semi-counterbalanced order. For 2000-m performance and [HCO3−], we examined differences in effects between conditions via pairwise comparisons, with differences interpreted in relation to the likelihood of exceeding smallest worthwhile change thresholds for each variable. We also calculated the within-subject variation (percent typical error).Results:There were only trivial differences in 2000-m performance between placebo (277 ± 60 W), acute bicarbonate (280 ± 65 W) and chronic bicarbonate (282 ± 65 W); however, [HCO3−] was substantially greater after acute bicarbonate, than with chronic loading and placebo. Typical error for 2000-m mean power was 2.1% (90% confidence interval 1.4 to 4.0%) for acute bicarbonate, 3.6% (2.5 to 7.0%) for chronic bicarbonate, and 1.6% (1.1 to 3.0%) for placebo. Postsupplementation [HCO3−] typical error was 7.3% (5.0 to 14.5%) for acute bicarbonate, 2.9% (2.0 to 5.7%) for chronic bicarbonate and 6.0% (1.4 to 11.9%) for placebo.Conclusion:Performance in 2000-m rowing ergometer trials may not substantially improve after acute or chronic bicarbonate loading. However, performances will be reliable with both acute and chronic bicarbonate loading protocols.

Role of ion transfer processes in acid-base regulation with temperature changes in fish

1984 ◽  
Vol 246 (4) ◽  
pp. R441-R451 ◽  
Author(s):  
N. Heisler
Keyword(s):  
Ion Transfer ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Fish Tissues ◽  
Model Calculations ◽  
Temperature Changes ◽  
Transfer Processes ◽  
Transfer Mechanisms

The contributions of transmembrane and transepithelial ion transfer processes and of nonbicarbonate buffering to the in vivo acid-base regulation have been evaluated. Model calculations were performed utilizing experimental data on transepithelial transfer of ions relevant for the acid-base regulation, the intracellular buffering properties of fish tissues, and the behavior of intracellular and extracellular pH and bicarbonate concentration with changes of temperature. The results of these studies indicate that the changes in the pK values of physiological nonbicarbonate buffers with changes in temperature support the adjustment of pH to lower values with rising temperature; however, transmembrane and transepithelial ion transfer mechanisms determine the acid-base regulation of intracellular and extracellular compartments.

CO2 and H+ Excretion by Swimming Coho Salmon, Oncorhynchus Kisutch

1983 ◽  
Vol 107 (1) ◽  
pp. 169-180
Author(s):  
GUIDO VAN DEN THILLART ◽  
DAVID RANDALL ◽  
LIN HOA-REN
Keyword(s):  
High Speed ◽  
Coho Salmon ◽  
Sea Water ◽  
Oncorhynchus Kisutch ◽  
Hydrogen Ion ◽  
Ion Transfer ◽  
Bicarbonate Concentration ◽  
Seawater Ph ◽  
External Conditions ◽  
Co2 Excretion

Coho salmon, Oncorhynchus kisutch (Walbaum), were swum at constant speed in a ‘Brett-type’ tunnel respirometer. Blood PO2, PCO2 and pH as well as total CO2 content and red blood cell pH were unchanged during swimming. The RE (respiratory exchange ratio) was slightly less than 0.7 when the fish was swimming in normal sea water, indicating that some CO2 retained by the fish. Lowering seawater bicarbonate concentration increased HCO3− transfer, presumably because of passive bicarbonate loss. A reduction in seawater pH from 7.95 to 7.1 sharply reduced both CO2 and hydrogen ion transfer, resulting in very low RE values of about 0.2. Hydrogen ion excretion was elevated during prolonged swimming following high speed swimming activity. It would appear that CO2 and hydrogen ion transfer by fish need not be matched and changing internal and external conditions can have a marked and separate effect on hydrogen ion and CO2 excretion and therefore on the RE value.

Factors affecting bromate removal capacity of zerovalent iron packed columns

2006 ◽  
Vol 6 (6) ◽  
pp. 119-130 ◽  
Author(s):  
C. Fan ◽  
C.H. Chan ◽  
L. Xie ◽  
C. Shang
Keyword(s):  
Zerovalent Iron ◽  
Minor Role ◽  
Sulfate Concentration ◽  
Quality Factors ◽  
Bicarbonate Concentration ◽  
Factors Affecting ◽  
Weight Percentage ◽  
Removal Capacity ◽  
A Minor ◽  
Aqueous Complexes

In a series of column experiments lasting for approximately 1500 pore volume, the effects of operational factors (flow rates, sand admixtures) and water quality factors (concentrations of DO, sulfate, phosphate and bicarbonate) on bromate removal capacity of zerovalent iron were investigated. The bromate removal capacity, obtained from migration of concentration profiles, was observed to decrease with increases in flow rate. In the case that 20 wt-% iron was replaced by sands, the bromate removal capacity increased, but, on the contrary, the bromate removal capacity inevitably decreased when the weight percentage was increased by two times. Dissolved oxygen played a minor role in decreasing the bromate removal capacity, this decreasing effect only prevailed near the proximal end of depassivating irons. The bromate removal capacity increased in the presence of 100 mg/L sulfate concentration but decreased when the sulfate concentration further increased. When comparing the effect on removal capacity for phosphate and sulfate, the inhibiting effect of phosphate on the bromate removal capacity was larger. Lastly, the removal capacity increased with increasing bicarbonate concentration, which may due to the formation of aqueous complexes.

Online estimation of VFA, alkalinity and bicarbonate concentrations by electrical conductivity measurement during anaerobic fermentation

2012 ◽  
Vol 65 (7) ◽  
pp. 1281-1289 ◽  
Author(s):  
Cesar-Arturo Aceves-Lara ◽  
Eric Latrille ◽  
T. Conte ◽  
Jean-Philippe Steyer
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Production ◽  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Anaerobic Fermentation ◽  
Simple Linear Regression ◽  
Conductivity Measurements ◽  
Bicarbonate Concentration ◽  
On Line

This paper describes the use of electrical conductivity for measurement of volatile fatty acids (VFA), alkalinity and bicarbonate concentrations, during the anaerobic fermentation process. Two anaerobic continuous processes were studied: the first was a laboratory reactor for hydrogen production from molasses and the second was a pilot process for anaerobic digestion (AD) of vinasses producing methane. In the hydrogen production process, the total VFA concentration, but not bicarbonate concentration, was well estimated from the on-line electrical conductivity measurements with a simple linear regression model. In the methane production process, the bicarbonate concentration and the VFA concentration were well estimated from the simultaneous on-line measurements of pH and electrical conductivity by means of non-linear regression with neural network models. Moreover, the total alkalinity concentration was well estimated from electrical conductivity measurements with a simple linear regression model. This demonstrates the use of electrical conductivity for monitoring the AD processes.

Comparison of the effects of parathyroid hormone (PTH) and recombinant PTH-related protein on bicarbonate excretion by the isolated perfused rat kidney

1990 ◽  
Vol 126 (3) ◽  
pp. 403-408 ◽  
Author(s):  
A. G. Ellis ◽  
W. R. Adam ◽  
T. J. Martin
Keyword(s):  
Parathyroid Hormone ◽  
Rat Kidney ◽  
Urine Volume ◽  
Clinical Manifestations ◽  
Fractional Excretion ◽  
Bicarbonate Concentration ◽  
Isolated Perfused Rat Kidney ◽  
Amino Terminal ◽  
Fractional Excretion Of Sodium ◽  
Perfused Rat Kidney

ABSTRACT The isolated perfused rat kidney was used to study the effects of amino-terminal fragments of human parathyroid hormone, hPTH(1–34), bovine parathyroid hormone, bPTH(1–84) and of PTH-related proteins, PTHrP(1–34), PTHrP(1–84), PTHrP(1–108) and PTHrP(1–141) on urinary bicarbonate excretion. PTHrP(1–34) (7 nmol/l), bPTH(1–84) (5·5 nmol/l) and hPTH(1–34) (7 nmol/l) had similar effects in increasing bicarbonate excretion with respect to the control. At lower concentrations (0·7 nmol/l) all PTHrP components, but not hPTH(1–34) or bPTH(1–84) increased bicarbonate excretion significantly. Infusions of PTHrP(1–108) and PTHrP(1–141) at 0·7 nmol/l, while associated with a rise in urinary bicarbonate concentration and excretion during the early stages of perfusion, produced a sharp decline in bicarbonate concentration and excretion in the latter part of perfusion. The different peptides produced no significant differences in glomerular filtration rate, fractional excretion of sodium or urine volume. The absence of substantial differences between the effects of hPTH(1–34) and PTHrP(1–34) are as noted in previous studies. The differences between PTHrP(1–108)/PTHrP(1–141) and PTHrP(1–34) demonstrated here are consistent with (1) the clinical manifestations of acidosis in hyperparathyroidism and alkalosis in humoral hypercalcaemia of malignancy, and (2) an independent action of a component of PTHrP beyond amino acids 1–34. Journal of Endocrinology (1990) 126, 403–408

scholarly journals Platelet metabolism during storage of platelet concentrates at 22 degrees C

Blood ◽  
1984 ◽  
Vol 64 (2) ◽  
pp. 406-414 ◽  
Author(s):  
H Kilkson ◽  
S Holme ◽  
S Murphy
Keyword(s):  
Platelet Count ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Buffering Capacity ◽  
Co2 Efflux ◽  
Platelet Concentrates ◽  
Bicarbonate Concentration ◽  
Free System ◽  
Co2 Transport

The development of methods for storing platelet concentrates (PCs) at 22 degrees C for transfusion has been predominantly empiric, with minimal knowledge of metabolic events occurring during storage. It is known that a decrease in pH due to accelerated production of lactic acid in hypoxic conditions is a major cause for loss of platelet viability. In the current studies, we have measured metabolic parameters such as O2 and glucose consumption rates and CO2 and lactic acid production rates. We have also determined the O2 and CO2 transport capacities of various containers and the buffering capacity of plasma. The O2 consumption rate was 1.10 +/- 0.16 (SD) nmol/min/10(9) platelets. In well-oxygenated systems, lactic acid formation was 1.74 +/- 0.12 nmol/min/mL PC for PCs with a platelet count of 1 to 2 X 10(9)/mL; and 0.52 mol of glucose was consumed per 1 mol lactic acid produced. In a completely oxygen-free system, lactic acid production increased 5–8-fold. These calculations suggest that 85% of energy generation is derived through oxidative metabolism and that glucose may not be the primary substrate for this metabolism. Bicarbonate concentration, initially 22.1 +/- 1.6 mEq/L, decreased 1.41 +/- 0.18 nEq/min/mL PC for PCs with counts 1 to 2 X 10(9) platelets/mL. The loss of bicarbonate was caused by displacement by lactic acid and as a consequence of spontaneous CO2 efflux from the container. CO2 production, 2.3 +/- 0.4 nmol/min/10(9) platelets, was derived from oxygen consumption and the CO2 liberated from bicarbonate as it was consumed. A rapid fall in pH to levels below 7.0 (22 degrees C) took place when the bicarbonate concentration fell below 5 mEq/L as lactate concentrations reached 20 to 25 mmol/L. A further increase in lactate concentration from 25 mmol/L to 40 mmol/L correlated with a further fall in pH to 5.8. Thus, the ultimate storage life of a PC is determined by continuous lactate production and the fixed buffering capacity of plasma and by the glucose concentration of the PC. With knowledge of these parameters, methods for predicting pH as a function of time, platelet count, and O2 and CO2 transport capability of the container have been developed as guidelines for future work.

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