Abstract: The Chair of Thermal Engineering at Poznan
University of Technology has been conducted research works on the
possibilities of using carbon nanostructures in energy and mechanics
applications for a couple of years. Those studies have provided results in a form of co-operation with foreign research centres, numerous publications and patent
applications.
Authors of this paper have studied the influence of multi-walled
carbon nanostructures on changes in static friction arising when steel
surfaces were moved. Tests were made using the original test stand
consisting of automatically controlled inclined plane driven by
precise stepper motors. Computer program created in the LabView
environment was responsible for monitoring of the stand operation,
accuracy of measurements and archiving the obtained results. Such a
solution enabled to obtain high accuracy and repeatability of all
conducted experiments.
Tests and analysis of the obtained results allowed us to determine
how additional layers of carbon nanostructures influenced on changes
of static friction coefficients. At the same time, we analyzed the
potential possibilities of applying nanostructures under consideration
in mechanics.
Abstract: Some physical properties of musk lime (Citrus
microcarpa) were determined in this study. The average moisture
content (wet basis) of the fruit was found to be 85.10 (±0.72) %. The
mean of length, width and thickness of the fruit was 26.36 (±0.97),
26.40 (±1.04) and 25.26 (±0.94) mm respectively. The average value
for geometric mean diameter, sphericity, aspect ratio, mass, surface
area, volume, true density, bulk density and porosity was 26.00
(±0.82) mm, 98.67 (±2.04) %, 100.23 (±3.28) %, 10.007 (±0.878) g,
2125.07 (±133.93) mm2, 8800.00 (±731.82) mm3, 1002.87 (±39.16)
kgm-3, 501.70 (±22.58) kgm-3 and 49.89 (±3.15) % respectively.
The coefficient of static friction on four types of structural surface
was found to be varying from 0.238 (±0.025) for glass to 0.247
(±0.024) for steel surface.