ARTIFICIAL FREEZING OF 1-YEAR-OLD SHOOTS OF APPLE VARIETIES

1961 ◽  
Vol 41 (2) ◽  
pp. 381-393 ◽  
Author(s):  
K. Lapins
Keyword(s):  
Electrical Conductivity ◽  
Cold Treatment ◽  
Temperature Drop ◽  
Late Winter ◽  
Conductivity Measurements ◽  
Freezing Damage ◽  
Apple Varieties ◽  
Artificial Freezing ◽  
One Year ◽  
Good Agreement

One-year-old shoots of 35 apple varieties and 6 clonal rootstocks were subjected to artificial cold treatment in three winters at three dates – early winter, mid-winter, and late winter. The rate of temperature drop was 0.7 °C. per hour and a minimum temperature of −37 °C. was maintained for 8 hours. The freezing damage was determined by evaluating discoloration of tissues shortly after treatment, by estimating recovery of treated material following 3 weeks’ forcing in the greenhouse, and by electrical conductivity measurements of water extracts from twig sections. Good agreement was obtained between the results of artificial freezing obtained in early or mid-winter and the known hardiness of varieties. Treatments in late winter, i.e. February or early March, did not produce reliable results. The recovery test gave consistent results if sufficient cold injury was produced, while the electrical conductivity measurements were most valuable in differentiating fine degrees of injury. The experience and the results obtained with known varieties seem to justify the suggestion that artificial freezing may successfully be used in screening unknown plant material for frost hardiness.

Electrical conductivity of low-pressure shock-ionized argon

1963 ◽  
Vol 17 (2) ◽  
pp. 182-192 ◽  
Author(s):  
P. R. Smy ◽  
H. S. Driver
Keyword(s):  
Electrical Conductivity ◽  
Shock Tube ◽  
Plasma Radiation ◽  
Conductivity Measurements ◽  
Flow Conditions ◽  
Velocity Measurements ◽  
Pressure Shock ◽  
Ionized Gas ◽  
Order Of Magnitude ◽  
Good Agreement

The electrical conductivity of shock-ionized argon produced in an electromagnetic shock tube of low attenuation has been measured at shock speeds of March 10–33, with initial pressures of 0·01–2·0 mm Hg. These measurements extend considerably the range of previous measurements performed with pressure-driven shock tubes. With the higher initial pressures or at the highest Mach numbers the measured conductivity is in good agreement with the previous measurements and with the Spitzer–Harm (1953) formula for the conductivity of a fully ionized gas. With the lower initial pressures (which have not previously been investigated) and at the lower March numbers the conductivity falls to less than half of the Spitzer-Harm value. Order-of-magnitude calculations show that diffusion of atoms, and heat conduction by the plasma atoms from the plasma to the shock-tube walls, can cause appreciable plasma cooling (and hence a reduction of the electrical conductivity) with the lowest initial pressures. This mechanism in conjunction with non-attainment of equilibrium ionization appears to explain the observed diminution in conductivity at the lowest pressures, but not the reduced conductivity at the medium pressures.Induced e.m.f. flow-velocity measurements indicate steady-flow conditions in the shock tube while photomultiplier measurements of the plasma radiation indicate that the column of shock-heated gas is 10–20 cm long; this latter figure is supported by the conductivity measurements. The fact that the length of the shock-heated gas column is not drastically shortened at low initial pressures in constrast to the work of Duff (1959), Roshko (1960) and Hooker (1961) is attributed to the fact that in this experiment both driver and driven gases are at high temperature.

Metastabile Deformationen in nematischen flüssigen Kristallen / Metastable Deformations in Nematic Liquid Crystals

1974 ◽  
Vol 29 (2) ◽  
pp. 310-318
Author(s):  
G. Heppke ◽  
F. Schneider
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Experimental Studies ◽  
Conductivity Measurements ◽  
Elastic Deformations ◽  
The Magnetic Field ◽  
Good Agreement

The magnetic field induced elastic deformations of nematic liquid crystals are studied theoretically. In accordance with the theory of Dafermos, two types of elastic deformations are predicted which differ in energy. The properties of the metastable deformations are discussed in detail. Experimental studies have been performed on MBBA using electrical conductivity measurements. Metastable deformations are obtained after rotating the direction of the magnetic field by more than 90° with respect to the direction of the homeotropically aligned sample. The observed conductivity values are in good agreement with theory.

THE SULPHURIC ACID SOLVENT SYSTEM: PART I. ACID-BASE REACTIONS

1960 ◽  
Vol 38 (8) ◽  
pp. 1363-1370 ◽  
Author(s):  
R. H. Flowers ◽  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Electrical Conductivity ◽  
Sulphuric Acid ◽  
Dissociation Constants ◽  
Solvent System ◽  
Conductivity Measurements ◽  
Acid Base ◽  
Acid And Base ◽  
System Part ◽  
Acids And Bases ◽  
Good Agreement

Acid–base reactions in the solvent sulphuric acid are discussed. Such reactions are conveniently studied by electrical conductivity measurements. A relation between the composition at which the conductivity has a minimum value and the strengths of the acid and base is derived. Values of the dissociation constants of acids and bases obtained in this way are shown to be in good agreement with values obtained by other methods.

scholarly journals Monitoring of earthen long linear embankments by geophysical tools integrated with geotechnical probes

2020 ◽  
Vol 195 ◽  
pp. 01031
Author(s):  
Stefano Utili
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Soil Electrical Conductivity ◽  
Conductivity Measurements ◽  
Calibration Period ◽  
Non Invasive ◽  
Electromagnetic Probe ◽  
Conductivity Variation ◽  
Electromagnetic Probes ◽  
Good Agreement

The use of electrical conductivity measurements from a non-invasive hand held electromagnetic probe is showcased to monitor the water content of earthen embankments at routine inspections. A methodology to convert the electrical conductivity measurements from the electromagnetic device into water content values is illustrated. The methodology is based on measuring the soil electrical conductivity variation with respect to a baseline reference condition and calibrating a water content – electrical conductivity relationship by comparing electrical conductivity readings from the electromagnetic probes with water content readings taken from geotechnical probes installed in a few sections of the embankment. The values of water content converted from the conductivity measurements according to the proposed procedure were found to be in very good agreement with independent measures of water content taken at times well beyond the calibration period.

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

Electrical conductivity studies on silica phases and the effects of phase transformation

2019 ◽  
Vol 104 (12) ◽  
pp. 1800-1805
Author(s):  
George M. Amulele ◽  
Anthony W. Lanati ◽  
Simon M. Clark
Keyword(s):  
Electrical Conductivity ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Hydrogen Charge ◽  
Charge Compensation ◽  
Composition Analysis ◽  
Conductivity Measurements ◽  
Pressure System ◽  
Electrical Conductivities ◽  
Silica Phases

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

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