THE HYDROGEN ION EFFECT IN WHISTLER DISPERSION

1960 ◽  
Vol 38 (12) ◽  
pp. 1642-1653 ◽  
Author(s):  
R. E. Barrington ◽  
T. Nishizaki

Four low-altitude whistlers have been carefully analyzed by a specially developed filtering technique. In each case the low-frequency portions of the resulting dispersion curves show similar departures from the simple [Formula: see text] law developed by Eckersley. The departures are found to be of the form and magnitude predicted by Storey on the assumption that the propagation is partly supported by the light hydrogen ions of the exosphere. If it is assumed that the observed deviations are due only to hydrogen ions, and that above some transitional level the positive ions are mostly hydrogen, an estimate of 1000 km for the height of the transitional level is obtained.

1994 ◽  
Vol 354 ◽  
Author(s):  
Shuji Kiyohara ◽  
Iwao Miyamoto

AbstractIn order to apply ion beam etching with hydrogen ions to the ultra-precision processing of diamond tools, hydrogen ion beam etching characteristics of single crystal diamond chips with (100) face were investigated. The etching rate of diamond for 500 eV and 1000 eV hydrogen ions increases with the increase of the ion incidence angle, and eventually reaches a maximum at the ion incidence angle of approximately 50°, then may decrease with the increase of the ion incidence angle. The dependence of the etching rate on the ion incidence angle of hydrogen ions is fairly similar to that obtained with argon ions. Furthermore, the surface roughness of diamond chips before and after hydrogen ion beam etching was evaluated using an atomic force microscope. Consequently, the surface roughness after hydrogen ion beam etching decreases with the increase of the ion incidence angle within range of the ion incidence angle of 60°.


1—In a previous paper experiments on the disintegration of lithium, boron, and carbon by heavy hydrogen ions were described. The experiments on boron showed the presence of three proton groups of ranges 31, 58, and 92 cm for deuteron energies of 500 kv. They showed also a continuous distribution of α-particles between the ranges 5 cm and 15 cm, the distribution having a maximum at about 9 cm. There were also indications of a homogeneous group of α-particles at the end of the distribution, but the numbers of particles obtained were not sufficient to allow of its existence being definitely established. Since these experiments, we have been able to obtain heavy hydrogen of much higher purity, and have improved our source of ions, so that we have been able to determine the distribution in energy of the α-particles with much greater precision. A further improvement has been made by applying magnetic analysis to our ion beam, for in our original experiments with a mixed beam of protons and deuterons, the α-particles of range less than 4 cm resulting from deuteron transmutations were masked by the large number of α-particles due to proton disintegrations.


2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Samiran Ghosh ◽  
Biplab Maity ◽  
Swarup Poria

The dynamical behaviour of weakly nonlinear, low-frequency sound waves are investigated in a plasma composed of only positive and negative ions incorporating the effects of a weak external uniform magnetic field. In the plasma model the mass (temperature) of the positive ions is smaller (larger) than that of the negative ions. The dynamics of the nonlinear wave is shown to be governed by a novel nonlinear equation. The stationary plane wave (analytical and numerical) nonlinear analysis on the basis of experimental parameters reveals that the nonlinear wave does have quasi-periodic and chaotic solutions. The Poincarè return map analysis confirms these observed complex structures.


Author(s):  
F. S. Zhang ◽  
T. R. Yu

Hydrogen ion is one kind of cation which possesses many properties common to all cations. Hydrogen ion also has its own characteristic features which are of particular significance for variable charge soils. The interactions between hydrogen ions and the surface of soil particles is the basic cause of the variability of both positive and negative surface charges of variable charge soils. The quantity of hydrogen ions in soils determines the acidity of the soil while the acidity of variable charge soils is among the strongest in all the soils. This strong acidity of variable charge soils affects many other chemical properties of the soil. In this chapter, the basic properties of hydrogen ions will be briefly discussed. Then, the products and the kinetics of the interaction between hydrogen ions and variable charge soils will be treated. The dissociation of hydrogen ions from the surface of soil particles has already been mentioned in Chapter 2. After the dissociation of an electron, a hydrogen atom becomes a proton (H+ ion). The ionization energy of hydrogen atoms is 1310 kj mol-1, whereas those of alkali metals, Li, Na, K, and Cs, are 519, 494, 419 and 377 kj mol-1, respectively. This difference in the ionization energy between hydrogen and alkali metals indicates that protons have a particularly strong affinity for electrons. Therefore, protons are apt to form a covalent bond with other atoms by sharing a pair of electrons, or to form a hydrogen bond. Because of the absence of an electronic shell, a proton has a diameter of the order of 10-13 cm, while other ions with electronic shells generally have a diameter of the order of 10-8 cm. Because a proton is so small, it is quite accessible to its neighboring ions and molecules. Therefore, there is very little steric hindrance when protons participate in chemical reactions. The above-mentioned features of proton are the basis for its particular properties. Free proton in solution is extremely unstable because it is very active. In an aqueous solution it will react with water molecules to form a hydrated proton, H3O+.


1927 ◽  
Vol 8 (6) ◽  
pp. 543-599 ◽  
Author(s):  
S. P. L. Sørensen ◽  
K. Linderstrøm-Lang ◽  
Ellen Lund

Introduction. A description is given of the principle followed in the experimental determination of the ionisation of egg albumin, its capacity to combine with acids and bases. Egg albumin is regarded as an ampholyte, and in accordance with J. N. Brønsted's definition of acids and bases, ampholytes are considered as substances capable of both taking up and giving off hydrogen ions. The theoretical treatment of the capacity of ampholytes to combine with acids (and bases) has been carried out on this basis. Section A. Several experimental series are noted, comprising the determination of the activity coefficient of the hydrogen ion (fH) in ammonium chloride solutions of different concentration. Section B. The general method of experimental determination of the ionisation (capacity to combine with adds and bases) of egg albumin in ammonium chloride and potassium chloride solutions is briefly described, and the results of the experiments are compared. Section C. 1). In a brief theoretical survey we have suggested that distinction should be made between isoelectric and isoionic reaction of an ampholyte, the former defined as the hydrogen ion activity (value of paH) at which the mean valency of the ampholyte is 0, the latter as the hydrogen ion activity at which the quantity of acid or base combined with the ampholyte is 0; or, as we prefer to express it, the hydrogen ion activity at which the specific hydrogen ionisation of the ampholyte is 0. If the ampholyte does not combine with other ions than the hydrogen ion, then isoelectric and isoionic reaction coincide. Isoionic reaction is determined by acid-combining experiments. The principle of this determination is briefly described. A theoretical investigation of the alteration with salt concentration of both isoelectric (isoionic) reaction and the shape and direction of the ionisation curves is made, with regard to ampholytes capable only of combining with hydrogen ions, on the basis of the Debye-Hückel formulæ and Linderstrøm-Lang's theory for the ionisation of polyvalent ampholytes of simple type. It is shown that the salt effect, in accordance with the theory, and in qualitative agreement with the experiments, consists in a turning of the ionisation curves, indicating the relation between the quantity of combined acid (specific hydrogen ionisation) and paH, and the turning of the curves, which leaves the isoelectric reaction unaltered, tends in such a direction that the quantity of combined acid at constant ampholyte concentration and constant pan increases with increasing salt concentration. The possibility of chemical combining of other ions than the hydrogen ion is discussed. 2). Following on 1), a brief survey of the experimental results is given. 3). The isoionic reaction is found from the experimental material and proved to be independent of the ammonium chloride concentration. As the mean of all determinations we have paH0 = 4.898 (isoionic reaction). The difference between this value and that formerly found for ammonium sulphate solutions (4.844) is discussed. 4). Finally, on the basis of the theory in Section 1), some simple calculations of the ionisation curves for egg albumin are made, and it appears that the theory can reproduce the experimental results in a rough quantitative way when we assume that the egg albumin has a radius of 2.21·10–7 cm. (answering to a molecular weight of 35,000 in aqueous solution), and contains 30 acid and base groups.


Author(s):  
O. M. Yonge

1. In the Lamellibranchs, as typified by Pecten maximus, Mya arenaria and Ensis siliqua, the entire, gut has an acid reaction, the stomach being the most acid region and the pH rising along the mid-gut and rectum.2. The origin of the acidity of the gut lies in the style. This has a low pH (5·4 in Pecten and Mytilus, 4·6 in Ensis and 4·45 in Mya), and, after it has been artificially extracted from Mya or induced to disappear, by keeping the animals under abnormal conditions, in Mytilus, Tapes and Pecten, the pH of the stomach invariably rises (by as much as 0·825 in Mya and 0·72 in Tapes), although the pH in the mantle cavity has fallen.3. The style, which dissolves rapidly in alkaline or weakly acid media, is not dissolved in fluids below a certain pH—4·4 for Ensis, 4·2 for Mya, 3·6 for Pecten and Mytilus.4. The style is never absent, even though animals are starved, so long as they are kept under otherwise healthy conditions. The disappearance of the style under abnormal conditions is probably due to a lowering of the vital activities, which include the secretion of the style substance, and the consequent dissolution of the style by the less acid contents of the stomach.5. The style is only maintained as a result of a balance between the rate of its secretion and the rate of its dissolution.6. There is a well-marked correlation between the tolerance of the presence of hydrogen ions possessed by the cilia from the various regions of the gut and the degree of acidity of the fluid with which they are normally surrounded.7. The pH of the gut in five Gastropods has been investigated. The fore-gut and stomach have invariably the lowest pH.8. This acidity may be caused by the salivary glands (Patella and Buccinum), the digestive gland (Doris and Aplysia), or the style (Crepidula).9. The mid-gut and rectum have a high pH, except in Doris, where there is little secretion of mucus, the gut being free and muscular.10. The style of Orepidula has similar properties to those of the Lamellibranchs. It has a pH of 5·8, and is not dissolved in fluid of pH 3·6 or lower.11. The cilia from the gut of Buccinum and Doris can function in a pH of 5·0, but there is little difference in the toleration of the various cilia to the presence of hydrogen ions.


2002 ◽  
Vol 93 (1) ◽  
pp. 181-188 ◽  
Author(s):  
Qihai Gu ◽  
Lu-Yuan Lee

To determine whether the excitabilities of pulmonary C fibers to chemical and mechanical stimuli are altered by CO2-induced acidosis, single-unit pulmonary C-fiber activity was recorded in anesthetized, open-chest rats. Transient alveolar hypercapnia (HPC) was induced by administering CO2-enriched gas mixture (15% CO2, balance air) via the respirator inlet for 30 s, which rapidly lowered the arterial blood pH from a baseline of 7.40 ± 0.01 to 7.17 ± 0.02. Alveolar HPC markedly increased the responses of these C-fiber afferents to several chemical stimulants. For example, the C-fiber response to right atrial injection of the same dose of capsaicin (0.25–1.0 μg/kg) was significantly increased from 3.07 ± 0.70 impulses/s at control to 8.48 ± 1.52 impulses/s during HPC ( n = 27; P < 0.05), and this enhanced response returned to control within ∼10 min after termination of HPC. Similarly, alveolar HPC also induced significant increases in the C-fiber responses to right atrial injections of phenylbiguanide (4–8 μg/kg) and adenosine (0.2 mg/kg). In contrast, HPC did not change the response of pulmonary C fibers to lung inflation. Furthermore, the peak response of these C fibers to capsaicin during HPC was greatly attenuated when the HPC-induced acidosis was buffered by infusion of bicarbonate (1.36–1.82 mmol · kg−1 · min−1 for 35 s). In conclusion, alveolar HPC augments the responses of these afferents to various chemical stimulants, and this potentiating effect of CO2 is mediated through the action of hydrogen ions on the C-fiber sensory terminals.


2018 ◽  
Vol 60 (5) ◽  
pp. 1029
Author(s):  
А.В. Савин

AbstractUsing the COMPASS force field, natural linear vibrations of graphane (graphene hydrogenated on both sides) nanoribbons are simulated. The frequency spectrum of a graphane sheet consists of three continuous intervals (low-frequency, mid-frequency, and narrow high-frequency) and two gaps between them. The construction of dispersion curves for nanoribbons with a zigzag and chair structure of the edges show that the frequencies of edge vibrations (edge phonons) can be present in the gaps of the frequency spectrum. In the first type of nanoribbons, two dispersion curves are in the low-frequency gap of the spectrum and four dispersion curves in the second gap. These curves correspond to phonons moving only along the nanoribbon edges (the mean depth of their penetration toward the nanoribbon center does not exceed 0.15 nm).


Sign in / Sign up

Export Citation Format

Share Document