ELECTRICAL PROPERTIES OF MUNG BEANS (Vigna Radiata L.)

This paper contains the results of measuring the electrical properties of mung beans (Vigna radiata L.) set. The conductivity and relative permittivity are the main parameters of dielectric material electrical properties. The electrical properties of mung beans samples had not been sufficiently measured, and the aim of this work was to perform the measurements of these properties. Measurements were performed under variable moisture content and the frequency of electric field from 0.1 kHz till 200 kHz for conductivity and in the range from 1 MHz to 16 MHz for relative permittivity, using RLC meter and Q meter, respectively. It was concluded that relative permittivity, and conductivity increased with increase of moisture content, resistivity, impedance, loss tangent, and relative permittivity decreased as the frequency of electric field increased, respectively.

PERMEABILITY AND MECHANICAL BEHAVIOUR OF MICROWAVE PRE-TREATED NORWAY SPRUCE RIPEWOOD

This is a studyofthe influence of microwave (MW) pre-treatment on the permeabilityof Norway spruceripewood(Picea abiesL. Karst)as it affects its mechanical properties. Specimens weretreated under variable moisture content,MW intensity,and impregnation processes. According to the results,thespecimens withaninitial moisture contentof 45–65% exhibited the highest permeabilityvaluescompared to referencesamples. Aninsignificant difference was found between MW pre-treatments at2 and3kW.Statistically significant results were found afterlong-time (24h) vacuum-pressureimpregnation(LP). Theaverage retention value followingLP was 132 kg.m-3, which isalmost threetimes greater thanthe MW-treatedgroupsimpregnated in ashort-time vacuum-pressure process. The average depth of penetration after LP was 2.0mm and the proportion of the impregnation area followingLP was 17.6%. MW pre-treatment had no effect on the impregnability or the mechanical propertiesof the wood; other MW regimes are open for further examination.