scholarly journals XI. The mobilities of the ions produced by Röntegen rays in gases and vapours

1909 ◽  
Vol 209 (441-458) ◽  
pp. 249-279 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Electric Field ◽  
Diffusion Coefficients ◽  
Negative Ions ◽  
Experimental Methods ◽  
Ionic Mobilities ◽  
Monovalent Ion ◽  
The Difference ◽  
A Current

For various reasons the determination of the velocities in an electric field of the ions produced in gases by the action of Röntgen rays is of fundamental importance in electrical theory. A knowledge of the ionic mobilities the velocities under unit electric intensity) affords information with regard to the structure of the ion; if, in addition, the diffusion coefficients of the ions in various gases are known, the charge associated with the ion can be compared with that carried by the monovalent ion in the electrolysis of solutions. Experimental methods of determining the mobilities of the positive and negative ions were devised not long after the ionising action of the Röntgen rays was known. Rutherford determined the values of the sum of the positive and negative mobilities in a series of gases. Zeleny, by comparing the velocity acquired by the ions in an electric field with that of a gaseous current parallel to the field, succeeded in deducing the values of the difference of the ionic mobilities and also their ratio. In later experiments Zeleny employed a current of gas in a direction perpendicular to the electric field and deduced the absolute values of the mobilities in air, oxygen, carbon dioxide, and hydrogen.

scholarly journals III. On the atomic weight of manganese

1883 ◽  
Vol 35 (224-226) ◽  
pp. 44-48
Keyword(s):  
Carbon Dioxide ◽  
Silver Chloride ◽  
Atomic Weight ◽  
Special Method ◽  
Its Analysis ◽  
A Current ◽  
Sulphuretted Hydrogen

Our attention has been directed for some time to a new determination of the atomic weight of manganese. This communication gives a succinct account of the results of the preliminary stages of such an inquiry, and although the further progress of the investigation may reveal some errors, still we feel convinced the final numbers can in no way differ materially from the present values, and therefore further delay in publication is unnecessary. The atomic weight of manganese has been determined by many chemists, but the resulting values vary considerably according to the special method selected. The results of the different investigators may be divided into two classes—those giving approximately 55 as the number, and those making it about 54. To the former class belong Turner, Berzelius, and Dumas, all of whom use the same method, viz., the determination of the silver chloride yielded by a weighed amount of chloride of manganese. Turner also made determinations from the analysis of the carbonate, and from the conversion of the monoxide into sulphate. Von Hauer used the same method as that employed by him in the determination of the atomic weight of cadmium, viz., the reduction of manganous sulphate to sulphide by ignition in a current of sulphuretted hydrogen. It is probable that this method is not very trustworthy, as, according to Schneider, the sulphide may be contaminated by oxysulphide. Schneider and Rawack belong to the second class of observers, the former employing the oxalate, and from its analysis calculating the atomic weight by deducting the weight of water and carbon dioxide obtained. Rawack, whose experiments were conducted in Schneider’s laboratory, weighed the water obtained by reducing manganoso-manganic oxide to manganous oxide.

scholarly journals Determination of Dissolved CO2 Concentration in Culture Media: Evaluation of pH Value and Mathematical Data

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1373
Author(s):  
Amir Izzuddin Adnan ◽  
Mei Yin Ong ◽  
Saifuddin Nomanbhay ◽  
Pau Loke Show
Keyword(s):  
Carbon Dioxide ◽  
Ph Value ◽  
Culture Media ◽  
Co2 Concentration ◽  
Co2 Solubility ◽  
Greenhouse Gasses ◽  
Dipotassium Phosphate ◽  
The Difference ◽  
Carbon Dioxide Co2

Carbon dioxide is the most influential gas in greenhouse gasses and its amount in the atmosphere reached 412 µmol/mol in August 2020, which increased rapidly, by 48%, from preindustrial levels. A brand-new chemical industry, namely organic chemistry and catalysis science, must be developed with carbon dioxide (CO2) as the source of carbon. Nowadays, many techniques are available for controlling and removing carbon dioxide in different chemical processes. Since the utilization of CO2 as feedstock for a chemical commodity is of relevance today, this study will focus on how to increase CO2 solubility in culture media used for growing microbes. In this work, the CO2 solubility in a different medium was investigated. Sodium hydroxide (NaOH) and monoethanolamine (MEA) were added to the culture media (3.0 g/L dipotassium phosphate (K2HPO4), 0.2 g/L magnesium chloride (MgCl2), 0.2 g/L calcium chloride (CaCl2), and 1.0 g/L sodium chloride (NaCl)) for growing microbes in order to observe the difference in CO2 solubility. Factors of temperature and pressure were also studied. The determination of CO2 concentration in the solution was measured by gas analyzer. The result obtained from optimization revealed a maximum CO2 concentration of 19.029 mol/L in the culture media with MEA, at a pressure of 136.728 kPa, operating at 20.483 °C.

scholarly journals On a new method for the determination of atmospheric carbon dioxide, based on the rate of its absorption by a free surface of a solution of caustic alkali

1905 ◽  
Vol 76 (507) ◽  
pp. 112-117 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Free Surface ◽  
Partial Pressure ◽  
Atmospheric Carbon Dioxide ◽  
Liquid Surface ◽  
Caustic Alkali ◽  
Optimal Velocity ◽  
Rate Of Absorption ◽  
A Current

In an appendix to a paper on the static diffusion of gases, communicated to the Society in 1900, it was shown that when a current of air containing a constant proportion of carbon dioxide is caused to move in a turbulent stream over the free surface of a solution of caustic alkali, the rate of absorption of that gas increases with the velocity of the air-current up to a certain optimal speed, beyond which no further increase in the speed of the current influences the rate of absorption. It was further shown that when the optimal velocity of the air-current has been reached, and the temperature is maintained practically constant, the rate of absorption then varies directly as the partial pressure of the carbon dioxide in the air. In other words, if under the above conditions the rate of absorption per unit of area of the liquid surface is a for a partial pressure of carbon dioxide represented by and is for a partial pressure of p' , then at similar temperatures, a / p = a' / p' . A suggestion was also made that this principle might be found applicable to a determination of the carbon dioxide in air, and that if the method were found to be a practical one it would have the manifest advantage of not requiring any measurement of the air from which the gas was absorbed.

scholarly journals The effect of water vapour on the diffusion coefficients of ions in nitrogen and oxygen

1933 ◽  
Vol 140 (841) ◽  
pp. 452-456
Keyword(s):  
Water Vapour ◽  
Diffusion Coefficients ◽  
Vapour Pressure ◽  
Negative Ions ◽  
Smooth Curve ◽  
Effect Of Water ◽  
Series Of Experiments ◽  
The Mean ◽  
Short Tube

In a previous paper an account has been given of an investigation of the effect of water vapour on the diffusion coefficients and mobilities of ions in air. It was found that as the concentration of water vapour in the air varied, the values of the diffusion coefficients for positive and negative ions showed rather wide oscillations. These oscillations appeared to be of an irregular character, but a long series of experiments showed that the values of the coefficients found for any vapour pressure could be reproduced with a considerable degree of accuracy. In a subsidiary investigation, it was found that the mean mobilities of the ions varied in the same way with vapour pressure, if the fields to which the ions were exposed were less than about 1.4 volts per centimetre. In stronger fields the oscillations were suppressed, the mobility values plotted against vapour pressure lying on a smooth curve. The method used for the determination of the diffusion coefficients was practically the same as that originally used by Townsend. The chief difference was the employment of only one long and one short tube for the capture of the diffusing ions, instead of the sets of 24 tubes in parallel used in Townsend’s apparatus. The ionization was produced by α -particles from polonium. A rather small volume of air, enclosed and kept at a definite humidity, was passed alternately through the long and the short tube, after exposure to the α -radiation, and the diffusion coefficient was calculated from the ratio of the concentrations of the ions in the issuing air by the use of Townsend’s formula.

Voltammetric determination of Al(III) with adsorptive preconcentration of the pyrocatechol violet complex

1991 ◽  
Vol 69 (9) ◽  
pp. 1418-1426 ◽  
Author(s):  
Dragic V. Vukomanovic ◽  
John A. Page ◽  
Gary W. Vanloon
Keyword(s):  
Metal Species ◽  
Aqueous Samples ◽  
Linear Calibration ◽  
Pyrocatechol Violet ◽  
Key Words Aluminium ◽  
Standard Additions ◽  
The Difference ◽  
A Current ◽  
Good Agreement

A method is described for the determination of aluminium in aqueous samples by linear scan voltammetry after adsorptive accumulation of the pyrocatechol violet (PCV) complex. A pH 6.5 triethanolamine/perchloric acid electrolyte is used for the determination with adsorption onto a mercury drop electrode at −0.50 V (vs a Ag/AgCl/satd KCl reference). Scanning cathodically after adsorption gave a current peak at −0.70 V for reduction of adsorbed PCV and a peak at −0.90 V for reduction of the adsorbed Al-PCV complex. The peaks were well resolved. Using 1.0 μM PCV and a 60 s adsorption period gave linear calibration curves for Al in the range 1 to 25 ng mL−1 Al. The detection limit was 0.1 ng mL−1 Al. For analysis, calibration by the method of standard additions is required. Most other metal species do not interfere, but vanadium (V(IV) and V(V)) forms a complex with PCV that is adsorbed and reduced at the same potential as Al–PCV. The interference may be eliminated by complexation of the V with citrate. Al and V present together may be determined by analysis in the absence of citrate (total: Al + V) and in the presence of citrate (Al); V is determined as the difference in the two values.The analysis of a range of samples with Al concentrations from 6 ng mL−1 to 3 μg mL−1 gave results which were in good agreement with those obtained by other methods. Key words: aluminium, pyrocatechol violet, adsorption, voltammetry, environmental.

scholarly journals Heme Iron Content in Lamb Meat Is Differentially Altered upon Boiling, Grilling, or Frying as Assessed by Four Distinct Analytical Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Azin Pourkhalili ◽  
Maryam Mirlohi ◽  
Ebrahim Rahimi
Keyword(s):  
Iron Content ◽  
Experimental Methods ◽  
Proximate Analysis ◽  
Heme Iron ◽  
Nonheme Iron ◽  
Total Iron ◽  
Cooking Methods ◽  
Lamb Meat ◽  
The Difference

Lamb meat is regarded as an important source of highly bioavailable iron (heme iron) in the Iranians diet. The main objective of this study is to evaluate the effect of traditional cooking methods on the iron changes in lamb meat. Four published experimental methods for the determination of heme iron were assessed analytically and statistically. Samples were selected from lambs' loin. Standard methods (AOAC) were used for proximate analysis. For measuring heme iron, the results of four experimental methods were compared regarding their compliance to Ferrozine method which was used for the determination of nonheme iron. Among three cooking methods, the lowest total iron and heme iron were found in boiling method. The heme iron proportions to the total iron in raw, boiled lamb meat and grilled, were counted as 65.70%, 67.75%, and 76.01%, receptively. Measuring the heme iron, the comparison of the methods in use showed that the method in which heme extraction solution was composed of 90% acetone, 18% water, and 2% hydrochloric acid was more appropriate and more correlated with the heme iron content calculated by the difference between total iron and nonheme iron.

scholarly journals A New Approach to Determine Gas Diffusion Coefficients in Porous Solids by EIS: Application for NH3 and CO2 Adsorption on Zirconia and Zeolite Type 5A

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Tien-Quang Nguyen ◽  
Maja Glorius ◽  
Cornelia Breitkopf
Keyword(s):  
Carbon Dioxide ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Gas Adsorption ◽  
Transport Coefficients ◽  
Gas Diffusion ◽  
Porous Solids ◽  
Ammonia Adsorption ◽  
Zeolite Type ◽  
The Difference

A new theoretical approach has been established to define transport coefficients of charge and mass transport in porous materials directly from impedance data; thus four transport coefficients could be determined. In case of ammonia adsorption on sulfated zirconia, the diffusion coefficient was figured out to be approximately the mobility diffusion coefficient of ammonium ions: 1.2 x 10-7 cm2/s. The transport of carbon dioxide was examined for samples of zeolite type 5A in different hydration states. By impedance spectroscopy measurements, the diffusion coefficient of water vapor at 373 K is estimated to be about 7 x 10-6 cm2/s. The influence of carbon dioxide adsorption on diffusion coefficients is studied based on two pellet types of zeolite 5A. The difference between polar and non-polar gas adsorption in porous solids is considered as changed characteristic of impedance.

scholarly journals V. The velocity of the ions produced in gases by Röntgen rays

1901 ◽  
Vol 195 (262-273) ◽  
pp. 193-234 ◽  
Keyword(s):  
Electric Field ◽  
Strong Electric Field ◽  
Direct Method ◽  
Negative Ions ◽  
Negative Ion ◽  
Saturation Current ◽  
Charged Ions ◽  
Oppositely Charged ◽  
A Direct Method

The electrical conductivity which is imparted to gases by their exposure to Röntgen rays has been explained by J. J. Thomson and E. Rutherford on the hypothesis of a formation of oppositely charged carriers throughout the volume of the gas. The motion of these carriers or ions when in an electric field constitutes the observed conductivity, and the recovery of the insulating property of a gas after an exposure to the rays is due partly to the recombination of the oppositely charged ions and partly to their impact with the boundaries. An estimate of the sum of the velocities with which the positive and negative ions move in air when in a unit electric field was first obtained by J. J. Thomson and E. Rutherford, and later E. Rutherford, by the same indirect method, determined the sum of the velocities of the ions in a number of gases. This method involved the determination of the rate of recombination of the ions, the saturation current obtained through the gas by the use of a strong electric field, and the current obtained with some small non-saturating electric force. E. Rutherford also describes an experiment in which the velocities of the two ions in air were obtained separately by a direct method, and found to be approximately equal. The writer has since shown that in general the two velocities are not equal, and for those gases for which the ratio of the two velocities was determined the negative ion moved the faster in nearly all cases.

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