electrical conductivity

Composite materials based on copolymers of polyvinylpyrrolidone and 2-hydroxyethylmethacrylate with combined fillers consisting of metal powders and graphite were obtained by the method of polymerization filling. The developed materials are characterized by sufficiently high physical and mechanical properties, increased electrical conductivity and water content. It was established that the addition of graphite to metal-filled copolymers increases the sensitivity of the electrical resistance of composites to moisture changes.

The purpose of the presented work was to model the electrical conductivity distribution in the northwestern part of the Ukrainian shield and to study the relationship of geoelectric anomalies with natural mineral deposits and with signs of possible tectonic activation of long-lived fault systems on the Shield. The methodology was based on long-period magnetotelluric and magnetovariational measurements in the period range of 3-16 to 2500-3600 s.

Electro­mag­ne­tic (EM) met­hods of ge­ophysics al­low to ima­ge the sub­sur­fa­ce con­duc­ti­vity distri­bu­ti­on by analyzing da­ta me­asu­red on the Earth sur­fa­ce. The tran­si­ent electro­mag­ne­tic (TEM) so­un­ding met­hod is a ti­me-do­ma­in control­led so­ur­ce one which uti­li­ze a non-sta­ti­onary tran­si­ent pro­cess of the EM fi­eld de­ca­ying in the con­duc­ti­ve me­di­um due to the step cur­rent ex­ci­ta­ti­on which is descri­bed by the He­avi­si­de functi­on.

A virtual device  for  assessing  the presence of heavy metals  in vegetables  is developed within  the LabVIEW systems  engineering  software.  The  quality  of  vegetable  juice  with  heavy  metals  contamination  is  studied  in  the  immitance-measuring way. Device  consists of  the  capacitive  transducer  (a  conductivity  cell  filled with  investigated  fluid – vegetable  juice with various additives), USB-6009 unit, connected to a computer with the full-speed USB interface.

Vegetables’  pollution  by  mercury,  copper,  zinc  and  arsenic  concerning  the  EU  standards  is  not  permitted, whereas in Ukraine it has to be within the limits of permissible concentrations. The urgent task is to develop an express method for controlling  the  concentrations  of  heavy  metals  in  vegetable  production. We  have  investigated  the  electrical  characteristics  of vegetable juices aiming the operative control of heavy metals concentrations in them.

The regional magneto-variational sounding method (aka Z/H method) was used for estimation of the Earth's mantle conductivity model at the Panagurishte (PAG) observatory region. A magneto-variational transfer function is calculated on the base of the relationship of vertical to horizontal geomagnetic field spectra components recorded on the Earth surface and priori assumptions about a field source structure. Inversions of the transfer function allow to obtain the one dimensional conductivity model.

Визначено критичну концентрацію міцелоутворення для водних розчинів
 поліакриламіду (ПАА) та промислового продукту Сульфороканол L270/1A (70% мас.

Досліджено міжмолекулярні взаємодії у водних розчинах поліакриламіду (ПАА) та
лауретсульфату натрію (ЛСН), як аніонної поверхнево-активної речовини (ПАР). На
основі вимірювання поверхневого натягу на межі “повітря-розчин”, електропровідності
та густини сумішей ПАА та ПАР підтверджено утворення асоціатів ПАР з
макромолекулами ПАА. За ізотермою поверхневого натягу визначено величину
критичної концентрації міцелоутворення ПАР, яка знаходиться в межах цієї величини
для аналогічних систем, які є відомими з літератури. Запропоновано узагальнюючу

Polyaniline is synthesized chemically under the influence of low magnetic field of intensity 1KGauss. The effect of magnetic field during the synthesis process causes enhancement of electrical conductivity by two orders of magnitude. This increased electrical conductivity depends on the polymer chain ordering, as well as structure and morphology of the reported polymer.

Effect of mechanical relaxations on the relaxation phenomena of electrical conducting polymer composites (ECPC) has been investigated. It has been experimentally shown that filler content significantly affects relaxation characteristics of the material. The main reason of these differences is the effect of the filler type on proceeding of relaxation processes. Rubbers with active carbon blacks display the ranges of slow and fast relaxations much more clearly than those with low active carbon black.