scholarly journals Low frequency electric properties utilization in agriculture and food treatment

2012 ◽  
Vol 49 (No. 4) ◽  
pp. 125-136 ◽  
Author(s):  
Z. Hlaváčová
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Moisture Content ◽  
Measurement Techniques ◽  
Conductivity Measurement ◽  
Membrane Properties ◽  
Food Treatment ◽  
Wide Range ◽  
Agricultural Materials

Determination of electrical properties is utilized in a wide range of disciplines and industries. A brief compendium of agricultural materials and food electrical properties exploitation is presented in this paper. The measurement of electrical conductivity or resistivity can be utilized at investigation of cell membrane properties on microscopic level. Moreover the electrical conductivity have utilization at the salinity of soils and irrigation water determination. Biological material properties are determined from their leachates too. The conductivity measurement are applied for determination of various characteristics of agricultural materials and food, for example for determination of the frost sensitiveness, of chilling and freezing tolerance, of moisture content, of seeds germination, of mechanical stress, of pasteurization, of other properties of grains, seeds, meat, sugar, milk, wood, soil, fruit and vegetable, infected food, … The utilization of dielectric properties are also described; for example in agricultural materials and food quality sensing (moisture content, maturity of fruit, freshness of eggs, potential insect control in seeds, radio frequency heating, …). The classification of permittivity measurement techniques at the low frequencies is mentioned.

Study of Method for Determination of Thermal Conductivity of Automotive Interior Materials

2014 ◽  
Vol 526 ◽  
pp. 46-51
Author(s):  
Li Xiong Zhang ◽  
Rong Gang Gao
Keyword(s):  
Thermal Conductivity ◽  
Conductivity Measurement ◽  
Transient Heat Conduction ◽  
Traditional Theory ◽  
Infinite Plane ◽  
Plane Source ◽  
Transient Plane Source ◽  
Wide Range ◽  
Automotive Interior

Based on the traditional theory of transient plane source for thermal conductivity measurement, this paper designed and developed a new pattern of heating and temperature sensing probe, presented the study of transient heat conduction of half-infinite plane while being heated, established a modified mathematical model of transient plane source method, and achieved the measurement of thermal conductivity of automotive interior material sample by the data processing method of mathematical iteration and liner regression using the modified transient plane source probe. According to the data of experiments, the instrument which this paper designed has a high precision of 5% and a wide range of 0.003-1W/(mK).This paper provides a practicable way for heat capacity determination of automotive interior materials.

Identification of Surface Quality of Plastic Electrodes after Blasting

2013 ◽  
Vol 334-335 ◽  
pp. 71-76
Author(s):  
B. Haluzíková ◽  
Jan Valíček ◽  
P. Škubala ◽  
Marta Harničárová ◽  
D. Bražina ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Roughness ◽  
Surface Characteristics ◽  
Injection Molding Process ◽  
Maximum Height ◽  
Molding Process ◽  
Arithmetic Average ◽  
Average Maximum ◽  
Wide Range

Nowadays, plastics have become one of the most demanded materials, replacing the traditional ones such as metals. Therefore, many companies are concerned with the production of plastics, with their distribution and innovation development. Plastics have found utility in a wide range of applications, we use them every day. Measurement of surface roughness of plastic moldings produced by the injection molding process was carried out by a contact profilometer Mitutoyo Surftest SJ401. A reason for this measurement is to obtain information about surface roughness. For further technical adjustment is required to have higher surface roughness what helps to increase electrical conductivity of plastic moldings. This involves determination of a ratio between Ra/Rz (the ratio between the arithmetic average of the roughness profile Ra and the average maximum height of the profile Rz) in order to satisfy customer demand for achieving better surface characteristics leading to an increase in electrical conductivity.

scholarly journals Development of Pressure-Responsive PolyPropylene and Biochar-Based Materials

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 339 ◽  
Author(s):  
Amir Noori ◽  
Mattia Bartoli ◽  
Alberto Frache ◽  
Erik Piatti ◽  
Mauro Giorcelli ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Plastic Deformation ◽  
Electrical Properties ◽  
Tea Leaves ◽  
Scanning Calorimetry ◽  
A Value ◽  
Wide Range ◽  
Order Of Magnitude

In this research paper, we reported the synthesis of biochar-based composites using biochar derived from exhausted tea leaves and polypropylene. The resulting materials were deeply characterized investigating mechanical (dynamic mechanical thermal analysis), thermal (thermogravimetrical analysis and differential scanning calorimetry), morphological (field emission scanning microscopy) and electrical properties vs. temperature. Furthermore, electrical conductivity was studied for a wide range of pressures showing an irreversible plastic deformation. An increment of one order of magnitude in the conductivity was observed in the case of 40 wt% biochar loading, reaching a value of 0.2 S/m. The material produced exhibited the properties of an irreversible pressure sensor.

Electrical properties of Athabasca Oil Sands

1979 ◽  
Vol 16 (10) ◽  
pp. 2009-2021 ◽  
Author(s):  
F. S. Chute ◽  
F. E. Vermeulen ◽  
M. R. Cervenan ◽  
F. J. McVea
Keyword(s):  
Electrical Properties ◽  
Moisture Content ◽  
Oil Sands ◽  
Relative Dielectric Constant ◽  
Dielectric Constants ◽  
Graphical Form ◽  
Oil Sand ◽  
Wide Range ◽  
Realistic Assessment

The results of a series of laboratory measurements of the electrical properties of samples of oil sand from the Athabasca deposit in northeastern Alberta are reported. The electrical conductivity and relative dielectric constant of the samples have been determined over a frequency range extending from 50–109 Hz. The measurements were performed on samples with a wide range of moisture content and over a temperature range from about 3–150 °C. A discussion of the methods and apparatus used is included.Sufficient data have been collected to permit correlation of the electrical properties of oil sand with density, moisture content, and temperature, and hence to indicate how the laboratory results can be extended to estimate in situ conductivities and dielectric constants. The results of these correlations, which are presented in graphical form, are of fundamental importance in any realistic assessment of the viability of electromagnetically heating large in situ deposits of oil sand.

In situ determination of water-saturated solidus by electrical discontinuity

2020 ◽  
Author(s):  
Xuan Guo ◽  
Huaiwei Ni
Keyword(s):  
Electrical Conductivity ◽  
Solidus Temperature ◽  
Conductivity Measurement ◽  
Aqueous Fluid ◽  
Electrical Conductivity Measurement ◽  
Rock System ◽  
Hydrous Melt ◽  
Water Saturated

<p><span>Water plays an important role in lowering melting temperature of rocks. The water-saturated solidus of rock is critical for understanding the magma generation and the dynamics of the Earth. There have been a lot of water-saturated solidi of rocks constrained by traditional quench method in literature. However, since both of the hydrous silicate melt and aqueous fluid can be quenched to glasses at high pressure, it is difficult to discriminate whether the quenched glasses were from melt or not. As a result, the water-saturated solidi of rocks from different studies may show significant discrepancy. One way to solve this problem is to detect the characteristics change of the rock system in situ, and electrical conductivity measurement is one of the good options. It is known that hydrous melt has much higher electrical conductivity than solid rock, and temperature is much more effective in enhancing melt electrical conductivity than that for aqueous fluid. Once the partial melting is triggered, the electrical conductivity of the water-saturated rock system may have remarkable increase if the hydrous melt is interconnected in the system. Accordingly, the abrupt change of electrical conductivity may mark the solidus temperature. In this study, we performed electrical conductivity measurement for the determination of water-saturated solidus of albite. We adopted albite as the starting material because its water-saturated solidus is well known, which can help to verify the accuracy our method, and its quenched products are not so controversial. The electrical conductivity measurements were carried out at four different pressures ranging from 0.35 GPa to 1.7 GPa in a 3/4″ piston cylinder apparatus with impedance spectroscopy. The obvious change of electrical conductivity was observed at solidus temperature within error, with increase of 1.8-0.18 log unit at 0.35-1.7 GPa. The results showed a stronger increase of conductivity at lower pressures, and fitted well with the water-saturated solidus of albite in literature. One defect of this method is the loss of water during experiment. The final water content in the system is about 1-2 wt%, comparing to the initial 10-15 wt% H<sub>2</sub>O. Nevertheless, the whole system is still water saturated, since water solubility in albite is fairly low. Therefore, if such a method can be improved to keep more water, it may be applied to other rocks to better constrain the water-saturated solidi in the future.</span></p><p> </p>

scholarly journals Development of a Device for Staged Determination of Water Activity and Moisture Content

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 881 ◽  
Author(s):  
Carlo Tiebe ◽  
Marc Detjens ◽  
Annika Fechner ◽  
Stefanie Sielemann ◽  
Andreas Lorek ◽  
...  
Keyword(s):  
Moisture Content ◽  
Water Activity ◽  
Bound Water ◽  
Free Water ◽  
Characteristic Parameter ◽  
Industrial Applications ◽  
Wide Range ◽  
Temperature Equilibrium

Moisture content and water activity are important parameters for quality characterizationof products like bulk materials, powders, granules. Thus, an exact determination is necessarilyrequired in a wide range of industrial applications. Moisture of materials is the content ofnon-chemically bound water in a solid or liquid. Water activity (aw) is a characteristic/parameter ofthe non-chemically bound (“free”) water in materials and is measured as humidity over asolid/liquid surface at constant temperature (equilibrium moisture content). It is an importantparameter to characterize the quality of e.g., pharmaceutical and food products. In ourcontribution, we present the developed MOISHUM device for staged determination of wateractivity and moisture content of liquid and solid materials.

scholarly journals The Study of The Electrical Conductivity and Activation Energy on Conductive Polymer Materials

2021 ◽  
Vol 4 (2) ◽  
pp. 71
Author(s):  
Balqyz Lovelila Hermansyah Azari ◽  
Totok Wicaksono ◽  
Jihan Febryan Damayanti ◽  
Dheananda Fyora Hermansyah Azari
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Activated Carbon ◽  
Electrical Properties ◽  
Mass Fraction ◽  
Conductive Polymers ◽  
Conductive Polymer ◽  
Conductivity Measurement ◽  
Polymer Materials ◽  
Electrical Conductivity Measurement

Conductive Polymers are one of the interesting topics to be developed in recent years. Conductive polymers can combine the properties of polymers and the electrical properties of metals. Research related to the electrical properties of conductive polymers, including electrical conductivity measurements and determination of activation energy has been carried out. This study aims to determine the effect of addition mass fraction of activated carbon into the nylon polymer on the conductive polymer material based on the electrical conductivity and activation energy. The variations of activated carbon used are 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% (wt/V). The conductive polymer from nylon polymer and activated carbon is made by casting solution method. The electrical conductivity measurement of the conductive polymer and the activation energy was carried out using the parallel plate method. The value of electrical conductivity increased from 5.62×10-9 ± 1.89×10-10 S/cm for the pure nylon to 2.51×10-8 ± 2.87×10-10 S/cm for the addition of mass fraction of activated carbon 8% wt/V. Meanwhile, there was a decrease in the addition of 9% wt/V and 10% wt/V of mass fraction of activated carbon, which were 2.36×10-8 ± 3.47×10-10 S/cm and 2.28×10-8 ± 4.01×10-10 S/cm. The activation energy of conductive polymer obtained decreased with increasing in the mass fraction of the activated carbon into the nylon polymer. The activation energy for the pure nylon was 0.0189 eV and 0.0127 eV for the addition of 8% wt/V mass fraction of activated carbon. Meanwhile, there was an increase in the addition of 9% wt/V and 10% wt/V mass fractions of activated carbon of 0.0145 eV and 0.0150 eV, respectively.

scholarly journals Conductivity Measurements of Silverpastes

10.14311/1221 ◽  
2010 ◽  
Vol 50 (4) ◽  
Author(s):  
M. Dirix ◽  
O. Koch
Keyword(s):  
Electrical Conductivity ◽  
Printed Circuit Boards ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Conductivity Measurement ◽  
Circuit Boards ◽  
Conductivity Measurements ◽  
New Materials ◽  
Printed Circuit

The development of three-dimensional printed circuit boards requires research on new materials which can easily be deformed. Conducting pastes are well suited for deformation even after they are applied to the dielectric carrier. This paper deals with measurements of the electrical conductivity of these conducting pastes. Two different conductivity measurement techniques are explained and carried out. The resulting measurements give an overview of the conductivity of several measured samples.

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