Absorption of Carbon Monoxide by Cuprous Salt Solutions. III. Electric Conductivity of the Solutions.

PEMFC (Polymer Electrolyte Membrane Fuel Cell) is widely considered as an energy conversion system from the chemical energy of hydrogen to electric energy. But, hydrogen fuel obtained from hydrocarbons has trace amount of carbon monoxide which is a potential poison for platinum electrode at the cell operating temperature ∼100 °C and it becomes a huddle for the general usage of PEMFC. On the other hand PAFC (Phosphoric Acid Fuel Cell) operates at a higher temperature and the platinum electrode oxidizes carbon monoxide poison while there is a leakage problem of the liquid phase. To combine the advantages of two fuel cells, the electrolyte systems of phosphoric acid supported silica on ceramics are recently being tested. In this study, we investigated the nm pore rice husk silica as a support for phosphoric acid and tested the electric conductivity of the silica plate and the characteristics of a prototype fuel cell H2|Pt|H3PO4/RHS|Pt|O2 at 100–200 °C. The conductivity of H3PO4/RHS was 8 mS cm −1 above 175 °C under 200 torr H2O. In the fuel cell, the apparent conductance of the electrolyte from I−V characteristics was 2.45 mS/cm at 160 °C under 1 atm H2 and air at present.

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Determination of the Electric Conductivity of Certain Salt Solutions

Physical Review ◽

10.1103/physrevseriesi.2.361 ◽

1895 ◽

Vol 2 (5) ◽

pp. 361-372

Author(s):

Albert C. MacGregory

Keyword(s):

Electric Conductivity ◽

Salt Solutions

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Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075968 ◽

1983 ◽

Vol 41 ◽

pp. 446-447

Author(s):

William F. Tivol ◽

Murray Vernon King ◽

D. F. Parsons

Keyword(s):

Electron Diffraction ◽

Heavy Atom ◽

Isomorphous Substitution ◽

X Ray Diffraction ◽

Salt Solutions ◽

X Ray ◽

Isomorphous Replacement ◽

Structure Factors ◽

Diffraction Structure ◽

The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

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Bulk standards for low-temperature biological x-ray microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111525 ◽

1984 ◽

Vol 42 ◽

pp. 282-283

Author(s):

P. Echlin ◽

M. McKoon ◽

E.S. Taylor ◽

C.E. Thomas ◽

K.L. Maloney ◽

...

Keyword(s):

Phase Separation ◽

Low Temperature ◽

Analytical Method ◽

Salt Solutions ◽

Absolute Concentration ◽

Cooling Process ◽

X Ray ◽

The Absolute ◽

Analytical Procedures ◽

Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

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