Infrared thermography (IRT) is a noninvasive and safe method of displaying the temperature map of objects that can be used to detect hoof diseases and lameness to reduce significant financial costs and physically stress animals. A qualitative bibliometric method based on the analysis of publications by the authors themselves using sophisticated tools of scientific databases was applied in this work. This review presents the fundamentals of IRT as well as recent developments in IRT detection in dairy science, including preprocessing, segmentation, and classification of objects in IRT images. In addition, recent studies dealing with the detection of hoof diseases and lameness using IRT are reviewed. As a result of this study, select previous studies are confronted in terms of technical aspects of IRT measurements such as emissivity, distance, temperature range, and reflected air temperature. Subsequently, recommendations for future IRT measurements are discussed.
The effect of 3D printing parameters by Fused Filament Fabrication (FFF) on the translucency of polylactic acid (PLA) parts was investigated. Six different printing parameters were studied: object orientation, layer height, nozzle temperature, fan speed, extrusion multiplier, and printing speed. The commercially available Plasty Mladeč PLA filament and the Original Prusa MK4 3D printer were used for the experiments. The translucency of the printed samples of 50 × 25 × 1 mm dimensions was measured using a luxmeter in an integrating sphere. A total of 32 sample combinations were created. Each sample was printed ten times. The results show that all investigated parameters significantly affect the optical properties of PLA parts. The best measured translucency values were obtained when printing in portrait mode, with a layer height of 0.30 mm, nozzle temperature of 240 °C, fan speed of 100%, 0.75 set extrusion multiplier, and a speed of 40 mm/s. ANOVA was used to statistically evaluate the effect of each parameter on translucency, and statistically significant differences were found between different combinations of parameters (p < 0.05). Scanning Electron Microscope (SEM) analysis provided detailed images of the surface structure of the printed samples, allowing for a better discussion of the microscopic properties affecting the translucency. The best print setting has an efficiency of 88% compared to the default setting of 65%. The ability of visible light to pass through the print (translucency) improved by 23%.
This article deals with a mutual comparison of indexable cutting inserts of the CNMG 120408 type from two different manufacturers during the machining of hardened steel AISI 4337 and austenitic stainless steel AISI 316 L. The main goal is to analyse the different wear processes depending on the difference in the manufacturer’s design and also depending on the properties of the different machined materials. The progress of the wear of the main spine of the tool, the types of wear and the service life of the cutting edge were monitored, with the achievement of the critical value VBmax = 300 µm being the standard. In addition to the wear of the inserts, the production of chips was monitored in terms of their shape, average size and number of chips per 100 g of chips produced. In order to understand the relationships arising from the obtained data, an SEM equipped with an elemental analyser was used to analyse the coating layers and the substrate of the unworn inserts and the types of wear and the intensity of the surface damage of the worn inserts. A several-fold difference in the lifetime of the cutting edge was found, both in terms of design and in terms of the selected machined material, while in both cases the cutting edge with Al2O3 and TiCN layers of half thickness achieved a better result in liveness. From the point of view of chip formation, very similar results in shape and average length were observed despite the different designs of chip breakers. Cutting inserts with half the thickness of the coating layers achieved longer cutting edge life in the non-primary material application compared to the target workpiece material. At the same time, it was observed that a thinner coating layer has a positive effect on chip formation in terms of its length and shape.
1 January 2024 in Journal of Physics: Conference Series
Most primary school students in the Czech Republic have a mobile phone. A mobile phone can measure many physical quantities once the appropriate application has been installed. The terms “Light Meter” or “Lux Meter” are names for applications that measure the physical quantity illuminance. At the time of writing, there are more than 50 such applications available on Google Play. These applications utilise data from the ambient light sensor. The study describes the measurement of illuminance using laboratory equipment and mobile phones with installed applications and further explores the reliability of data collected by mobile phones. A comparison was made between data from applications that were in the default settings and calibrated. The values of different applications installed on the same mobile phone were compared, as well as values of the same application installed on different mobile phones. Values were compared at different distances from the light source and at the same distance, but with varying angles. The reaction time for a mobile phone application to detect changes in illumination was measured. Sensitivity to infrared and ultraviolet radiation was also investigated. Seven general conclusions were drawn from all measurements regarding the use of a mobile phone as a luxmeter instead of professional laboratory equipment, provided that the recommendations are followed.
Concepts of heat, specific heat capacity and other terms of thermal physics are very For their better understanding it is necessary in teaching to include newly conceived experiments focused on the everyday experience of students. The paper evaluates the thermal phenomena with the help of infrared camera, respectively surface temperature sensors for on-line measurement. The article focuses on the experimental verification of the law of conservation of energy in thermal physics, comparing specific heat capacity of various substances and their confrontation with established experience of pupils.