Temat: wilgotnosc ziarna - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Metodyczne zagadnienia monitoringu statusu wody w wybranych materialach biologicznych
Methodical questions of monitoring of water status in selected biological materials
Autorzy:: Malicki, M A
Powiązania:: https://bibliotekanauki.pl/articles/1630378.pdf
Data publikacji:: 1999
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: agrofizyka
materialy biologiczne
zboza
ziarno
drewno
gleby
woda glebowa
wilgotnosc gleby
wilgotnosc ziarna
wilgotnosc drewna
temperatura
zasolenie gleb
potencjal wodny gleby
pomiary wilgotnosci
natlenienie
monitoring
agrophysics
biological material
cereal
grain
wood
soil
soil water
soil moisture
grain moisture
wood moisture
temperature
soil salinity
soil water potential
moisture measurement
oxygenation
Opis:: Methodical questions of monitoring of water status in soil, cereals grain and wood are discused ( where monitoring is understood as registration of time and spatial variability of selected properties). Amount of viariables which is necessary in order to determine water status depends on the complexion of the considered phenomena and is, so far, the matter of arbitrary choice. In most practical cases the water status is expressed only by moisture of the considered material ( like the building timber). In practical terms, two variables suffice to express water status in cereal grain: moisture and temperature. To describe water status in the soil not less then five variables are needed: amount of water (the soil moisture) soil water potential, salinity, oxygenation and temperature. The only sensors that can be integrated in modern data acquisition system must be read electrically. Therefore electroresistance and electrocapacitance methods were considered. Dielectric sensors were recognized as the proper choice.Soil is a complex material having instable characteristics. For this reason it is the most difficult task to monitor soil water status, particularly to determine the soil moisture. Therefore it has been assumed that measuring methods verified for the soil will be also suitable for other, less complex materials. Thus, monitoring of soil water status was mainly discussed. Special attention was focused to the time domain reflectometry, TDR, as the semi selective method for the soil moisture and salinity determination.
Źródło:: Acta Agrophysica; 1999, 19; 1-108
1234-4125
Pojawia się w:: Acta Agrophysica
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Tarcie ziarna pszenicy
Friction of wheat grain
Autorzy:: Molenda, M
Horabik, J.
Grochowicz, M.
Szot, B.
Powiązania:: https://bibliotekanauki.pl/articles/1628372.pdf
Data publikacji:: 1995
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: agrofizyka
materialy sypkie
zboza
pszenica
ziarno
wilgotnosc ziarna
gestosc ziarna
tarcie zewnetrzne
tarcie wewnetrzne
wspolczynnik tarcia
metody pomiarow
przyrzady pomiarowe
wlasciwosci mechaniczne
procesy technologiczne
agrophysics
granular material
cereal
wheat
grain
grain moisture
grain density
external friction
internal friction
friction coefficient
measurement method
measurement device
mechanical property
technological process
Opis:: All phases of particulate material industry, namely, storage, handling and processing are operations that require precise knowledge of the behaviour of the material to achieve the desired control.External and internal friction of particulate material greatly influence its mechanical behaviour.A lot of work was done on agricultural grain since 1960`s. This work summarizes the methods and results of these studies and presents the results of the autor1s own experiments. It was divided into two parts: 1.Internal friction and 2. External friction. Own studies for the first section were performed using direct shearing box and triaxial compression chamber which dimensions were anlarged to regard the size of cereal grain. Density, moisture content of grain and its spatial orientation were taken into account as the most important factors forinternal friction. All of them were found to influence significantly the angle of internal friction of grain. For the external friction section own method of measurements was applied. Friction coefficient was measured for a part of wheat grains sliding against a steel or glass platesandwiched between them. The true contact area of grain with a flat glass surface was measured with microscope photography in reflected light. The relations between tangential force and normal force on the one hand and the true contact area versus normal force on the other were obtained and examined. Parameters taken into account were: grain moisture content, type of endosperm, cutin cover, variety, location of cultivation, and roughness of sliding surface and that of grain itself. All these factors were found to influence significantly obtained frictional characteristics. The obtained results pointed out to the fact that both internal and external friction of cereal grain depend on a number of factors which caused unexplained scatter of experimental results, and in a greater part of theoretical works were left out of account.
Źródło:: Acta Agrophysica; 1995, 04; 3 - 88
1234-4125
Pojawia się w:: Acta Agrophysica
Dostawca treści:: Biblioteka Nauki