scholarly journals III. The influence of stress and strain on the physical properties of matter. Part II. electrical conductivity- continued . The alteration of the electrical conductivity of cobalt, magnesium, steel, and platinum-iridium produced by longitudinal traction; Discovery of simple relations between the ‘critical points’ of metals

1884 ◽  
Vol 37 (232-234) ◽  
pp. 386-391 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistance ◽  
Unit Area ◽  
Specific Resistance ◽  
Stress And Strain ◽  
Moderate Amount ◽  
Iron Cobalt ◽  
Temporary Decrease ◽  
Permanent Increase ◽  
Cobalt And Nickel

The effect of temporary longitudinal traction on the electrical resistance of cobalt was determined by a method similar to that already described in a former portion of this memoir, and it was found that, like nickel, this metal has its resistance decreased by moderate temporary stress, in spite of the changes of dimensions which ensue. Whether the decrease of resistance would be changed to increase, as it is with nickel, by a greater amount of stress, has not yet been ascertained, but should this be the case, the magnitude of the stress per unit area which would suffice for the purpose must be much greater with cobalt than with nickel. As with nickel, permanent extension and rolling diminish the effect of temporary longitudinal traction, so that there is a larger decrease of resistance caused by a given stress with annealed than with unannealed cobalt. Cobalt is remarkable for the extreme persistence with which the same load, when applied again, and again, continues to produce per­ manent increase of resistance, and probably increase of length, but for a moderate amount of permanent extension the increase of resistance is more than accounted for by the permanent increase of length and diminution of section which take place; so that, as with iron and nickel, the specific resistance is decreased by moderate permanent extension. The permanent decrease of specific resistance per unit for unit permanent increase of length is, for iron, cobalt, and nickel, 0.02, 1.44, and 2.37 respectively; thus the permanent decrease of specific resistance, as well as the temporary decrease of resistance, is greater with nickel than with cobalt.

scholarly journals Modeling the influence of thermal modification on the electrical conductivity of wood

Holzforschung ◽  
2014 ◽  
Vol 68 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Christian Brischke ◽  
Kathrin A. Sachse ◽  
Christian R. Welzbacher
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Moisture Content ◽  
Electrical Resistance ◽  
Specific Resistance ◽  
Thermal Modification ◽  
Heat Treated ◽  
Wood Temperature ◽  
Color Data

Abstract A model has been developed aiming at the description of the effect of thermal modification on the electrical conductivity of wood. The intention was to calculate the moisture content (MC) of thermally modified timber (TMT) through the parameters electrical resistance R, wood temperature T, and CIE L*a*b* color data, which are known to correlate well with the intensity of a heat treatment. Samples of Norway spruce (Picea abies Karst.) and beech (Fagus sylvatica L.) samples were thermally modified in laboratory scale at 11 different heat treatment intensities and the resistance characteristics of the samples were determined. Within the hygroscopic range, a linear relationship between the resistance characteristics and the mass loss (ML) through the heat treatment was established. Based on this, a model was developed to calculate MC from R, T, and ML. To validate this model, color values of 15 different TMTs from industrial production were determined for estimation of their ML and fed into the model. MC of the 15 arbitrarily heat-treated TMTs was calculated with an accuracy of ±3.5% within the hygroscopic range. The material-specific resistance characteristics based on experimental data led to an accuracy of ±2.5%.

scholarly journals The influence of stress and strain on the physical pro­perties of matter. Part II. Electrical conductivity ( continued ).The alteration of the electrical conductivity of cobalt, magnesium, steel, and platinum-iridium by longi­tudinal traction

1886 ◽  
Vol 39 (239-241) ◽  
pp. 503-531
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistance ◽  
Royal Society ◽  
Stress And Strain ◽  
Previous Communication

In a previous communication to the Royal Society,* I pointed out that whilst with iron the electrical resistance is temporarily increased by temporary longitudinal traction, that of nickel is decreased, pro­vided the stress be not carried beyond a certain limit, and this, too, in spite of the change of dimensions, namely, increase of length and diminution of diameter, which follow from the stress.

scholarly journals Construção de um sensor de condutividade elétrica do solo: uma proposta multidisciplinar

2019 ◽  
Vol 40 ◽  
pp. 107
Author(s):  
Fernando Siqueira Scherer ◽  
Silvana Maldaner ◽  
Matheus Vinícius dos Santos Mello ◽  
Priscila Bernardeli Miranda ◽  
Andrei Da Cunha Lima ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistance ◽  
Voltage Drop ◽  
Specific Resistance ◽  
Low Cost ◽  
Input Voltage ◽  
Important Variable ◽  
Simple Circuit ◽  
Conductive Plate ◽  
The Wire

The electrical conductivity of the soil is an important variable in agriculture. Their knowledge is essential in fertirrigation and can assist in soil management1. Thus, the proposal of this work is the development of a sensor to determine the electrical conductivity of the soil at low cost. To determine the electrical conductivity, the second law of Ohm (R = ρ (l / A)) is used. The equation of this law relates the electrical resistance of a conductor, with the length of the wire, area of straight section of the wire and the resistivity (or specific resistance of the material). Physically, the electrical conductivity (σ) is the inverse of the resistivity (ρ). Thus, with a microcontroller, an Arduino, a control resistor and conductive plate electrodes, a simple circuit is created to measure the electrical conductivity. The input voltage is 5v, the resistance of the control resistor is 500kohms, with this information the current in the circuit is calculated and the voltage drop in the circuit and consequently the electrical conductivity of the ground is determined.

Progress in preparation and characterization of silylene iron, cobalt and nickel complexes

2021 ◽  
Author(s):  
Wenjing Yang ◽  
Yanhong Dong ◽  
Hongjian Sun ◽  
Xiaoyan Li
Keyword(s):  
Nickel Complexes ◽  
Electron Cloud ◽  
Synthesis And Characterization ◽  
Iron Cobalt ◽  
Cloud Density ◽  
Cobalt And Nickel

The synthesis and characterization of Fe, Co and Ni complexes supported by silylene ligands in recent ten years are summarized. Due to the decrease of electron cloud density on Si...

Sign in / Sign up

Export Citation Format

Share Document