scholarly journals Chemical characteristics of precipitation and hydrogen input in throughfall and stemflow under some eastern Canadian forest stands

1983 ◽  
Vol 13 (5) ◽  
pp. 948-955 ◽  
Author(s):  
M. K. Mahendrappa
Keyword(s):  
Weighted Average ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Chemical Characteristics ◽  
Weighted Mean ◽  
Hydrogen Ion Concentration ◽  
Average Value ◽  
Ph Values ◽  
Nitrate N ◽  
Forest Experiment Station

At the Acadia Forest Experiment Station (AFES) in central New Brunswick chemical characteristics of rain samples collected at five different locations were determined during the 1977–1981 period. Throughfall and stemflow samples from six softwood and three hardwood stands were collected and chemically characterized starting from the early 70's. In 1976 two of four plots in each of the stands were treated with urea at a rate of 225 kg N•ha−1. Both the quantities of rain and their pH values varied considerably between collections, months, and years. The weighted mean pH of summer (May–October) rain collected intensively during the 1977–1981 period ranged from 4.5 to 5.1, with an overall weighted average value of 4.75 for the 5 years. Sulfur and nitrate N measured during May–October 1982 amounted to 6.18 and 1.52 kg•ha−1, respectively, for the 6-month period. The concentration of hydrogen ion in the throughfall was less than that in the rain. Hardwood throughfall had lower hydrogen levels (higher pH) than the softwood throughfall. The pH of the stemflow from softwoods was lower than that of rain in most cases. Although not significantly, the hydrogen ion concentration of both throughfall and stemflow on the fertilized plots was lower than on the untreated plots. The hydrogen load of rain was reduced by all tree species, but there was considerable variation between species in their abilities to decrease total hydrogen reaching the soil.

THE ELECTRODE POTENTIAL OF IRON IN RELATION TO HYDROGEN ION CONCENTRATION

1936 ◽  
Vol 14b (1) ◽  
pp. 31-40 ◽  
Author(s):  
J. W. Shipley ◽  
J. H. Shipley
Keyword(s):  
Electrode Potential ◽  
Chloride Ion ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Iron Electrode ◽  
General Corrosion ◽  
Citrate Buffer ◽  
Hydrogen Ion Concentration ◽  
Electrically Conducting ◽  
Ph Values

The electrode potential of iron immersed in phosphate, borate and citrate buffers of varying hydrogen ion concentration was measured, using a normal calomel electrode as the second half of the cell. Breaks in the potential of the iron electrode amounting to as much as 0.7 volts were found to occur at definite pH values for each series of buffers. The electrode exhibited an "initial" and "final" potential depending on the pH of the electrolyte and the time of immersion, the "final" value requiring several days to become established. The "final" break in the electrode potential of 0.74 volts in the pure phosphate buffer occurred between a pH of 3.1 and 4.0, that in the pure borate buffer, of 0.75 volts, occurred between a pH of 4.3 and 4.6, and in the pure citrate buffer, of 0.77 volts, between a pH of 10.1 and 10.9. The effect of chloride ion and de-aeration on the electrode potential was observed. It is suggested that the potential of the iron electrode is determined by the presence or absence of a non electrically conducting film or deposit on the iron, the formation of which is a function of the nature of the electrolyte and its hydrogen ion concentration. De-aeration apparently had no effect on the electrode potential, but the presence of chloride ion affected the establishing of the "final" potential and caused the break in voltage to appear irregularly at a much lower hydrogen ion concentration.At pH values below that at which the break in potential occurred, corrosion of the iron electrode was marked, and the electrode potential remained high, while, at pH values above the break, corrosion was virtually inhibited or confined to local spots on the electrode, and the electrode potential remained low. The presence of the chloride ion stimulated local corrosion and permitted general corrosion to proceed at a lower hydrogen ion concentration.

scholarly journals The Hydrogen Ion Concentration of the Cells of some Marine Algæ

1922 ◽  
Vol 12 (4) ◽  
pp. 785-788 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Marine Algae ◽  
Plant Cells ◽  
Hydrogen Ion ◽  
Land Plants ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Optimum Ph ◽  
Acid Character

The measurements recorded for marine algæ of various groups show that the reaction of the sap is in most cases almost neutral, and in no case is the sap of the pronounced acid character met with in many land plants. This being so it follows that the enzymes concerned in the metabolism of these algæ must be quite different from those which effect corresponding changes in land plants, as may be seen on referring to the optimum pH values for various enzymes quoted in the writer's previous paper on the reaction of plant cells (1922).

scholarly journals THE EFFECT OF HYDROGEN ION CONCENTRATION ON SWELLING OF CELLS

1926 ◽  
Vol 9 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Baldwin Lucke ◽  
Morton McCutcheon
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Wide Range

1. The effect of HCl, NaOH, CO2, and NH3 on the volume of unfertilized Arbacia eggs was tested over a wide range of pH values. 2. No swelling occurred, except in HCl solutions, and there not until after injury or death had occurred. 3. Whereas the volume of erythrocytes and of proteins such as gelatin is known to be dependent on the pH of the solution, such a relation does not exist in the case of living and uninjured cells, at least of the type tested.

scholarly journals INFLUENCE OF TEMPERATURE AND HYDROGEN ION CONCENTRATION UPON THE SPORE CYCLE OF BACILLUS SUBTILIS

1919 ◽  
Vol 1 (4) ◽  
pp. 421-428 ◽  
Author(s):  
Arao Itano ◽  
James Neill
Keyword(s):  
Ph Value ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Practical Application ◽  
Vegetative Cells ◽  
Hydrogen Ion Concentration ◽  
Influence Of Temperature ◽  
Ph Values ◽  
Metabolic Products ◽  
Slight Growth

1. At 5°C. no germination took place. 2. At 25°C. and at 37°C. germination occurs if the hydrogen ion concentration of the broth is kept between pH 5 and pH 10, but not at higher or lower pH values. 3. The completion of the spore cycle likewise requires a hydrogen ion concentration between pH 5 and pH 10. 4. The spores can germinate when the pH value is 10, although after germination the vegetative cells multiply only to a very slight extent and soon pass into spores. 5. The slight growth and multiplication of vegetative cells in broth of pH 10 suggest that the formation of endospores in this medium must be caused largely by the unfavorable reaction of the medium rather than by the accumulation of metabolic products. 6. Automatic adjustment of the medium seems to play a rôle in the completion of the spore cycle. 7. The results are not only of theoretical importance but they have a practical application to the preservation of food by canning and by other methods.

Phosphate transport in the proximal convoluted tubule: effect of intraluminal pH

1984 ◽  
Vol 246 (3) ◽  
pp. F323-F333 ◽  
Author(s):  
G. A. Quamme ◽  
N. L. Wong
Keyword(s):  
Parathyroid Hormone ◽  
Ph Value ◽  
Phosphate Transport ◽  
Phosphate Concentration ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Plasma Phosphate ◽  
Hydrogen Ion Concentration ◽  
Phosphate Absorption ◽  
Ph Values

The effect of intraluminal hydrogen ion concentration on phosphate absorption was evaluated in the rat superficial proximal tubule. Early proximal convoluted tubules were perfused in vivo with buffered equilibrium solutions, and the saturation kinetics for phosphate transport was determined by altering intraluminal phosphate concentration at pH values of 7.65 and 6.5. The apparent Jmax and Km parameters of phosphate transport were about twofold greater with intraluminal pH 7.65 compared with pH 6.5 values. Accordingly, intraluminal hydrogen ion had a direct effect on tubular phosphate transport. Endogenous or exogenously administered parathyroid hormone inhibited phosphate absorption at both pH values, indicating that the phosphaturic action of parathyroid hormone is independent of the intraluminal pH value. Elevation of plasma phosphate inhibited phosphate absorption unrelated to the intraluminal phosphate concentration at both pH values. These data suggest that elevation of plasma phosphate may decrease phosphate absorption by inhibiting efflux from the cell into the peritubular capillary. In conclusion, proximal phosphate absorption is determined by the intraluminal pH value, circulating parathyroid hormone level, and plasma phosphate concentration acting through separate cellular and membrane mechanisms.

scholarly journals THE PERMEABILITY OF LIVING CELLS TO DYES AS AFFECTED BY HYDROGEN ION CONCENTRATION

1922 ◽  
Vol 5 (2) ◽  
pp. 223-224 ◽  
Author(s):  
Marian Irwin
Keyword(s):  
Living Cell ◽  
Quantitative Method ◽  
Living Cells ◽  
Low Ph ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Rate Of Penetration ◽  
Cresyl Blue ◽  
Ph Values

1. An accurate quantitative method of measuring the penetration of dye into the living cell is described. 2. Cresyl blue is unable to penetrate rapidly unless the pH outside the cell is decidedly greater than that inside. The rate of penetration increases with increasing pH. 3. Around pH 9 penetration of the dye is rapid while the reverse is true of exosmosis. At low pH values (5.9) exosmosis is rapid and penetration is very slow.

scholarly journals THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE INDUCTION OF POLARITY IN FUCUS EGGS

1937 ◽  
Vol 21 (1) ◽  
pp. 57-70 ◽  
Author(s):  
D. M. Whitaker ◽  
E. W. Lowrance
Keyword(s):  
Oxygen Tension ◽  
Concentration Gradient ◽  
Sea Water ◽  
Capillary Tube ◽  
Hydrogen Ion ◽  
Developmental Pattern ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values

1. When a Fucus egg develops near one end in a close fitting capillary tube of pyrex glass or silica (quartz), diffusion of substances passing to and from the egg is more impeded on the side of the egg toward the far end of the tube. 2. The egg therefore develops in a gradient of its own diffusion products, and of oxygen tension. 3. More than 600 eggs have been reared, each near one end in a capillary, in sea water at various regulated and measured pH values. 4. When the medium, which is initially homogeneous inside and outside the capillary, is initially at pH 6.5 to 7.6, nearly all of the eggs develop rhizoid protuberances on the sides of the eggs toward the far ends of the capillaries. This is on the sides of the eggs where the concentration of substances diffusing from the eggs is greatest. 5. The polarity and developmental pattern of the egg is thus determined either by a concentration gradient of products diffusing from it, or by a gradient of oxygen tension. The former interpretation is favored. 6. This is regarded as an extension of earlier observations that rhizoid protuberances form on the sides of two neighboring eggs in the direction of the neighbor if the sea water is acidified. 7. It appears hardly possible that a mitogenetic effect could be responsible for the response of an egg to its own diffusion gradients. 8. When the medium is made more basic, the percentage of the eggs which form rhizoid protuberances toward the far end of the tube decreases to about 20 or 25 per cent between pH 8.1 and 8.6. The response of the egg to the gradients which it produces is thus statistically reversed. The determination of the polarity of the eggs by the diffusion gradients does not become as complete in alkalinized as in acidified sea water. 9. When the pH of the sea water is elevated to 9.1 or 9.2, salts precipitate out. The type of development is altered and the control of the diffusion gradients over the polarity of the eggs decreases.

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