Variation of Electrical Conductivity With Water Content in Agarose Gel

2002 ◽  
Author(s):  
Adriana L. Vega ◽  
Hai Yao ◽  
Marc-Antoine Justiz ◽  
Weiyong Gu
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Normal Tissue ◽  
Tumor Tissue ◽  
Biological Tissues ◽  
Specific Electrical Conductivity ◽  
Agarose Gel ◽  
Similar Relationship ◽  
Ion Concentrations ◽  
The Relationship

Specific electrical conductivity, a material property of biological tissues, has been found to be greater in tumor tissue than in normal tissue on account of its higher water content [1]. Its value is related to water content, ion concentrations, and ion diffusivities within biological tissues [e.g., 1,2,3]. The variation in conductivity with water content is hypothesized to be related to the change in ion diffusivities [5,6]. The objective of this study is to investigate the relationship between conductivity and water content in hydrogels. The main goal is to develop a similar relationship for biological tissues and to understand deformation-dependent ion diffusivity in tissues under mechanical loading.

Relationship of the s1-elements halogenides melts specific electric conductivity with alkali metals specific electric conductivity

2019 ◽  
Vol 60 (12) ◽  
pp. 116-124
Author(s):  
Ivan K. Garkushin ◽  
◽  
Olga V. Lavrenteva ◽  
Yana A. Andreeva ◽  
◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electric Conductivity ◽  
Alkali Metals ◽  
Analytical Description ◽  
Specific Electrical Conductivity ◽  
Molten Metals ◽  
Specific Electric Conductivity ◽  
Metal Melts ◽  
Relationship Of ◽  
The Relationship

The paper presents an analytical description of the relationship of the specific electrical conductivity æ of individual alkali metals haloganides melts (MHal) (M – Li, Na, K, Rb, Cs, Fr; Hal – F, Cl, Br, I) and the specific electrical conductivity æ(M) of alkali metal melts for temperatures (Тпл + n) (Tпл – melting temperature K; n = 5, 10, 50, 75, 100, 150, 200° higher melting temperatures of MHal and metals) and the specific electrical conductivity of alkali metals at standard temperature using M.Kh. Karapetyans comparative methods. The relationship of properties æ(MHal при Тпл+n) = f(æ(MHal при Тпл+5)), æ(FrHalТпл+n) = f(æ(FrHalТпл+5°)) is described in the "property-property" coordinates. A comparative analysis of the specific electrical conductivity values of francium haloganides melts obtained by the proposed methods was carried out. The possibility of calculating the electrical conductivity of molten salts from the electrical conductivity of molten metals is shown. It is shown that the equation æ(MHal)0.5 = a + bæ(M)1.5 can be used to calculate the specific electrical conductivity of francium haloganides melts. The calculation of the specific electrical conductivity using various equations shows the consistency of the numerical values obtained.

Organic semiconductors: Simple and complex salts of 1-methyl-3-alkylimidazolium 7,7,8,8-tetracyano-p-quinodimethane

1983 ◽  
Vol 48 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Miloslav Šorm ◽  
Stanislav Nešpůrek ◽  
Miloslav Procházka ◽  
Igor Koropecký
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Organic Semiconductors ◽  
Alkyl Group ◽  
Specific Electrical Conductivity ◽  
Lithium Salts ◽  
Decomposition Products ◽  
Radical Salt ◽  
Complex Salts ◽  
Hydrolysis Of

By metathesis between lithium salts of 7,7,8,8-tetracyano-p-quinodimethane and 1-methyl-3-alkylimidazolium bromides, simple radical salts were prepared whose specific electrical conductivity values are c. 10-7-10-3, Ω-1 m-1, according to the donor structure. Combining these salts with neutral 7,7,8,8-tetracyano-p-quinodimethane (TCNQ°) gave complex salts with an electrical conductivity higher by 7-3 orders of magnitude which increase monotonically with increasing volume of the alkyl group. The compounds are stable in anhydrous conditions also in presence of oxygen, and if irradiated by daylight. The rate constant of hydrolysis of these salts is proportional to the water content in solution and inversely proportional to the content of neutral TCNQ° in the simple radical salt. The hydrolysis is predominantly activated by light absorbed by the decomposition products.

scholarly journals MODELING OF THE ANISOTROPY OF THE SPECIFIC ELECTRICAL CONDUCTIVITY OF BIOLOGICAL TISSUE ARISING AT LOCAL COMPRESSION BY BIPOLAR WELDING ELECTRODES

2021 ◽  
Vol 2021 (2) ◽  
pp. 13-19
Author(s):  
Yu.М. Lankin ◽  
◽  
V.G. Soloviev ◽  
I.Y. Romanova ◽  
◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electric Fields ◽  
Biological Tissue ◽  
Biological Tissues ◽  
Geometric Interpretation ◽  
Physical Experiment ◽  
Geometric Parameters ◽  
Successive Approximations ◽  
Specific Electrical Conductivity ◽  
Method Of Successive Approximations

Current publications on bipolar welding use the electrical characteristics of uncompressed biological tissue. This reduces the accuracy of calculating the distribution of the density of the flowing currents and the strength of the electric fields in the zone of the fabric to be welded when it is squeezed. The aim of the work is to show a methodology for calculating the change in the specific electrical conductivity of biological tissue under local compression by electrodes and the effect of this factor on the results of modeling electrical processes of biological welding. A geometric interpretation of the change in the electrical conductivity of the pig's heart muscle when squeezed by bipolar welding electrodes in relative units is proposed. The principle of similarity of the geometric parameters of the physical experiment and the graphic model of COMSOL multyphysics is used, as a result of which the dependences of the three main geometric parameters of the model on the magnitude of the relative compression are determined. The method of successive approximations of the values of the total electrical resistance of biological tissue in a physical experiment at frequencies of 0,3, 30, and 300 kHz and the calculated resistances on the model with a change in the basic geometric parameters of specific electrical conductivity was used. A model of bipolar welding of biological tissues is obtained, which takes into account the anisotropy factor of the electrical conductivity of biological tissue under compression. Some results of investigations of the regularities of the current flow in the tissue, taking into account the arising anisotropy, are presented. References 12, figures 5, tables 4.

LIMITATIONS OF CANCER MARGIN DELINEATION BY MEANS OF AUTOFLUORESCENCE IMAGING UNDER CONDITIONS OF LASER SURGERY

2010 ◽  
Vol 03 (01) ◽  
pp. 45-51 ◽  
Author(s):  
ALEXANDRE DOUPLIK ◽  
AZHAR ZAM ◽  
RALPH HOHENSTEIN ◽  
ANGELOS KALITZEOS ◽  
EMEKA NKENKE ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Normal Tissue ◽  
Tumor Tissue ◽  
Surgical Navigation ◽  
Er:Yag Laser ◽  
Biological Tissues ◽  
Fluorescent Light ◽  
Autofluorescence Imaging ◽  
Wavelength Band ◽  
Surgical Guidance

Limitations of cancer margin delineation and surgical guidance by means of autofluorescence imaging under conditions of laser ablation were investigated and preliminary results are presented. PinPoint™ (Novadaq Technologies Inc., Canada) was used to capture digital images and Er:YAG laser (2.94 μm, Glissando, WaveLight™, Germany) was exploited to cause laser ablation on both normal and cancer sites of the specimen. It was shown that changes of the autofluorescence image after ablation extend beyond the actual sizes of the ablation loci. The tumor tissue after the laser ablation starts to emit fluorescent light within the green wavelength band (490–550 nm) similar to normal tissue stating that the current technology of in-process tissue classification fails. However, when the autofluorescence was collected in the red range (600–750 nm), then the abnormal/normal contrast was reduced, but still present even after the laser ablation. The present study highlights the importance of finding a proper technology for surgical navigation of cancer removal under conditions of high power effects in biological tissues.

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