The Activity of Phytase as Determined by the Specific Conductivity of Phytin-Phytase Solutions.

1921 ◽  
Vol 13 (4) ◽  
pp. 317-318 ◽  
Author(s):  
F. A. Collatz ◽  
C. H. Bailey
Keyword(s):  
Specific Conductivity

scholarly journals Strain Sensor Based on Biological Nanomaterial

2021 ◽  
Vol 6 (1) ◽  
pp. 23
Author(s):  
Levan P. Ichkitidze ◽  
Alexander Yu. Gerasimenko ◽  
Dmitry V. Telyshev ◽  
Eugeny P. Kitsyuk ◽  
Vladimir A. Petukhov ◽  
...  
Keyword(s):  
Screen Printing ◽  
Respiratory Diseases ◽  
Specific Conductivity ◽  
Strain Sensor ◽  
Aqueous Dispersion ◽  
Strain Sensors ◽  
Bending Angle ◽  
Multi Walled Carbon Nanotubes ◽  
Number Of Cycles ◽  
Walled Carbon Nanotubes

We investigated a prototype of a strain sensor based on the layers of a bionanomaterial containing bovine serum albumin (BSA matrix) and multi-walled carbon nanotubes (MWCNT filler). The aqueous dispersion of 25 wt.% BSA/0.3 wt.% MWCNT was applied by screen printing onto flexible polyethylene terephthalate substrates. After drying the layers by laser irradiation (~970 nm), various parameters of the layers were controlled, i.e., resistance R, bending angle θ, number of cycles n, and measurement time. One measurement cycle corresponded to a change within the range θ = ±150°. The layers of the BSA/MWCNT bionanomaterial had dimensions of (15 ÷ 20) mm × (8 ÷ 10) mm × (0.5 ÷ 1. 5) µm. The dependences of resistance R on the bending angle θ were similar for all layers at θ = ±30, and the R(θ) curves represented approximate linear dependences (with an error of ≤ 10%); beyond this range, the dependences became nonlinear. The following quantitative values were obtained for the investigated strain sensor: specific conductivity ~1 ÷ 10 S/m, linear strain sensitivity ~160, and bending sensitivity 1.0 ÷ 1.5%/°. These results are high. The examined layers of the bionanomaterial BSA/MWCNT as a strain sensor are of particular interest for medical practice. In particular, strain sensors can be implemented by applying a water dispersion of nanomaterials to human skin using a 3D printer for monitoring movements (arms and blinking) and the detection of signs of pathology (dysphagia, respiratory diseases, angina, etc.).

Electrohydrodynamic stability: Taylor–Melcher theory for a liquid bridge suspended in a dielectric gas

2002 ◽  
Vol 452 ◽  
pp. 163-187 ◽  
Author(s):  
C. L. BURCHAM ◽  
D. A. SAVILLE
Keyword(s):  
Surface Tension ◽  
Dielectric Constant ◽  
Electric Fields ◽  
Liquid Bridge ◽  
Numerical Solutions ◽  
Specific Conductivity ◽  
Axisymmetric Deformation ◽  
Aspect Ratios ◽  
The Stability ◽  
Theory And Experiment

A liquid bridge is a column of liquid, pinned at each end. Here we analyse the stability of a bridge pinned between planar electrodes held at different potentials and surrounded by a non-conducting, dielectric gas. In the absence of electric fields, surface tension destabilizes bridges with aspect ratios (length/diameter) greater than π. Here we describe how electrical forces counteract surface tension, using a linearized model. When the liquid is treated as an Ohmic conductor, the specific conductivity level is irrelevant and only the dielectric properties of the bridge and the surrounding gas are involved. Fourier series and a biharmonic, biorthogonal set of Papkovich–Fadle functions are used to formulate an eigenvalue problem. Numerical solutions disclose that the most unstable axisymmetric deformation is antisymmetric with respect to the bridge’s midplane. It is shown that whilst a bridge whose length exceeds its circumference may be unstable, a sufficiently strong axial field provides stability if the dielectric constant of the bridge exceeds that of the surrounding fluid. Conversely, a field destabilizes a bridge whose dielectric constant is lower than that of its surroundings, even when its aspect ratio is less than π. Bridge behaviour is sensitive to the presence of conduction along the surface and much higher fields are required for stability when surface transport is present. The theoretical results are compared with experimental work (Burcham & Saville 2000) that demonstrated how a field stabilizes an otherwise unstable configuration. According to the experiments, the bridge undergoes two asymmetric transitions (cylinder-to-amphora and pinch-off) as the field is reduced. Agreement between theory and experiment for the field strength at the pinch-off transition is excellent, but less so for the change from cylinder to amphora. Using surface conductivity as an adjustable parameter brings theory and experiment into agreement.

The Specific Conductivity of Protozoan Cultures.

1929 ◽  
Vol 26 (7) ◽  
pp. 605-606
Author(s):  
E. H. Slifer ◽  
E. C. Herber ◽  
R. Blumenthal ◽  
T. P. Sun ◽  
C. C. Wang
Keyword(s):  
Specific Conductivity

scholarly journals Effect of solvent composition on the critical micelle concentration of sodium deoxycholate in ethanol-water mixed solvent media

BIBECHANA ◽  
2012 ◽  
Vol 9 ◽  
pp. 63-68 ◽  
Author(s):  
Ajaya Bhattarai ◽  
Sujit Kumar Shah ◽  
Ashok Kumar Yadav ◽  
Janak Adhikari
Keyword(s):  
Critical Micelle Concentration ◽  
Precise Measurement ◽  
Mixed Solvent ◽  
Volume Fraction ◽  
Pure Water ◽  
Specific Conductivity ◽  
Sodium Deoxycholate ◽  
Solvent Composition ◽  
Effect Of Solvent

The precise measurement of the specific conductivity of sodium deoxycholate in pure water and ethanolwater mixed solvent media containing 0.10 and 0.20 volume fraction of ethanol at 303.15 K are reported. The concentration were varied from ~ 0.01 mol L-1 to ~ 0.0002 mol L-1.The conductivity of sodium deoxycholate decreases with the increase in the volume fraction of ethanol. The critical micelle concentration of sodium deoxycholate increases with the increase in the volume fraction of ethanol. DOI: http://dx.doi.org/10.3126/bibechana.v9i0.7176 BIBECHANA 9 (2013) 63-68

Electrical Conductivity of Magnesium Oxide/Molten Carbonate Eutectic Coexisting System

2019 ◽  
Vol 74 (9) ◽  
pp. 739-742
Author(s):  
Elena V. Nikolaeva ◽  
Andrey L. Bovet ◽  
Irina D. Zakiryanova
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Magnesium Oxide ◽  
Solid Phase ◽  
Specific Conductivity ◽  
Maxwell Model ◽  
Impedance Method ◽  
Molten Carbonate ◽  
Carbonate Ions ◽  
Alkali Carbonate

AbstractThe electrical conductivity of molten ternary alkali carbonate eutectic, coexisting with MgO particles, has been investigated. The conductivity was measured by the AC impedance method. The apparent activation energy ΔEa increased with the MgO content. This fact can be attributed to the effect of the solid phase. The specific conductivity of those systems could not be described using the Maxwell model over the solvation process of the carbonate ions on the particles of the magnesium oxide.

scholarly journals The Bakerian lecture —Regularities and irregularities in the ionosphere—I

1937 ◽  
Vol 162 (911) ◽  
pp. 451-479 ◽  
Keyword(s):  
Specific Conductivity ◽  
Wave Length ◽  
Ground Level ◽  
Short Wave ◽  
The State ◽  
Total Conductivity ◽  
The Sun ◽  
Magnetic Studies ◽  
Short Wave Length ◽  
Radio Measurements

Our knowledge concerning the state of the atmosphere lying above about 80 km. in height has been derived from experiments on radio wave reflexion as well as from studies of terrestrial magnetism and of the aurora. The information derived from radio experiments is, fortunately, in the nature of a supplement to, rather than a duplicate of, information derivable in other ways. As one of the best examples in this connexion may be mentioned the question of electrical conductivity. Here the magnetic studies of Schuster and Chapman yield an estimate of the total conductivity for currents travelling horizontally, whereas the radio measurements give the state of ionization at different levels from which the specific conductivity at those levels may be estimated. One of the most striking things about the ionosphere is the marked solar control. Speaking generally it may be said that the ionization increases and decreases as the sun rises and sets. Again, speaking generally, we may say that the main part of the ionization is caused by solar-violet light. The rays from the sun meet the outer layers of the atmosphere first and the short wave-length radiation is absorbed there, causing ionization. It thus comes about that the study of the ionosphere becomes the study of an interesting part of the sun's spectrum which cannot be detected at ground level. It also becomes the study of certain atomic processes such as photo-ionization, recombination of ions and attachment of electrons to neutral molecules such as cannot be investigated at very low pressure in the laboratory, because of the influence of the walls of the vessel confining the gas.

Sign in / Sign up

Export Citation Format

Share Document