Electrical conductivity: A simple and sensitive method to determine emulsifying capacity of proteins

2021 ◽  
Author(s):  
Anqi Guo ◽  
Youling L. Xiong
Keyword(s):  
Electrical Conductivity ◽  
Emulsifying Capacity ◽  
Sensitive Method

scholarly journals A sensitive method for observing changes of electrical conductivity in single hygroscopic fibres

1924 ◽  
Vol 96 (674) ◽  
pp. 181-193 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Conduction ◽  
The State ◽  
Atmospheric Conditions ◽  
Imperfect Contact ◽  
Air Movement ◽  
Experimental Values ◽  
Sensitive Method

Some years ago, after noticing that an inconstant and excessive leak from the insulated system of an electroscope was due to a barely visible filament of spider’s web, the author was struck by the beautiful way in which the arrangement responded to changing atmospheric conditions. An attempt to adapt this observation to the study of the absorption of moisture by fibrous substances has led to the method described in this paper. Our expectations as to its possibilities have been more than realised. The effect of changes in atmospheric conditions upon the state of fibrous substances, as indicated by their electrical conduction, can be followed continuously. The conductivity time curves, shown in figs..3a, 3b, 5a and 5b, where the actual experimental values are plotted, are typical examples of the accuracy obtainable. Bulk methods of measuring the conductivity of hygroscopic fibrous substances have always given complex results. By examining microscopic amounts, such as single cotton hairs 1 cm. long, we are able to reduce errors incurred by ( a ) imperfect contact, ( b ) pockets of moisture trapped in the interstices of the fibrous mass, ( c ) difficulties of conditioning large quantities of material under compression as a consequence of restriction of air movement ( d ) displacement (under pressure) of absorbed moisture from the materials whose structures are, in effect, like that of a sponge.

scholarly journals A simple and sensitive method for determination of Norfloxacin in pharmaceutical preparations

2015 ◽  
Vol 51 (2) ◽  
pp. 429-437 ◽  
Author(s):  
Zhuo Ye ◽  
Le Wang ◽  
Jianguo Wen
Keyword(s):  
Electrical Conductivity ◽  
Linear Response ◽  
Present Method ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Voltammetric Sensor ◽  
Experimental Conditions ◽  
Sensitive Method

<p>In this approach, a new voltammetric method for determination of norfloxacin was proposed with high sensitivity and wider detection linear range. The used voltammetric sensor was fabricated simply by coating a layer of graphene oxide (GO) and Nafion composited film on glassy carbon electrode. The advantage of proposed method was sensitive electrochemical response for norfloxacin, which was attributed to the excellent electrical conductivity of GO and the accumulating function of Nafion under optimum experimental conditions, the present method revealed a good linear response for determination of norfloxacin in the range of 1×10<sup>-8</sup>mol/L-7×10<sup>-6</sup> mol/L with a detection limit of 5×10<sup>-9</sup> mol/L. The proposed method was successfully applied in the determination of norfloxacin in capsules with satisfactory results.</p>

Removing Substrate Background in TEM Microanalysis

1974 ◽  
Vol 32 ◽  
pp. 568-569
Author(s):  
John C. Russ ◽  
Nicholas C. Barbi
Keyword(s):  
Electrical Conductivity ◽  
Rapid Growth ◽  
Organic Film ◽  
Absolute Concentration ◽  
Background Signal ◽  
X Ray ◽  
Elemental Concentrations ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

1983 ◽  
Vol 41 ◽  
pp. 606-607
Author(s):  
Klaus-Ruediger Peters ◽  
Samuel A. Green
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Critical Point ◽  
Metal Films ◽  
High Magnification ◽  
Osmium Impregnation ◽  
Instrumental Resolution ◽  
20 Nm ◽  
Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

Total Body Electrical Conductivity Measurements in the Neonate

1991 ◽  
Vol 18 (3) ◽  
pp. 611-627 ◽  
Author(s):  
Marta L. Fiorotto ◽  
William J. Klish
Keyword(s):  
Electrical Conductivity ◽  
Conductivity Measurements ◽  
Total Body

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

ELECTRICAL CONDUCTIVITY BEHAVIOUR OF Gd DOPED EuO UNDER HYDROSTATIC PRESSURE

1980 ◽  
Vol 41 (C5) ◽  
pp. C5-219-C5-222
Author(s):  
J. P. Desfours ◽  
C. Godart ◽  
J. P. Nadai ◽  
A. Mauger ◽  
G. Weill ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hydrostatic Pressure ◽  
Conductivity Behaviour
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