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Abstract

Trueness and precision of a method for determining the water content (%) of food and chemical products based on infrared radiation with a wavelength in the range (2.70÷7.21 μm) was evaluated. The most accurate measurements for food products were obtained when the heat source was a radiant heater with a radiation wavelength of 7.21 μm, a trueness deviation of 0.01%. When heated with radiation with wavelengths (from 3.32 μm to 7.21 μm), the trueness of the measurement ranged (0.03% ÷0.13%) for chemical products. The shortest analysis time for food products was found when the analysis was carried out using an IR source with a wavelength of 7.21 μm, while for chemical products, a heat source with a wavelength of 2.70÷7.21 μm was optimal. According to the results of the analysis, the use of IR radiation with a wavelength range of 3.32÷7.21 μm is an alternative for accurate measurements.
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Authors and Affiliations

Sławomir Janas
1
Małgorzata Kowalska
2

  1. Centre for Metrology Research and Certification, Radwag Wagi Elektroniczne, Poland
  2. Faculty of Chemical Engineering and Commodity Science, Kazimierz Pulaski University of Technology and Humanities in Radom, Poland
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Abstract

The paper presents the algorithms for kinematic analysis, trajectory planning, dynamics of kinematic chain and driving units elaborated for manipulators and robots with kinematic chains of serial structure with revolute pairs with perpendicular or parallel axes. Elastic deflections of driving units as well as action of external forces on end-effector have been taken into account. The simulating software was created using the modular structure of modeling process. The application of software for testing the robots accuracy and running speed acc. to ISO 9283 is also presented.
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Authors and Affiliations

Andrzej A. Stępniewski
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Abstract

Tensile structures in general, achieve their load-carrying capability only after the process of initial form-finding. From the mechanical point of view, this process can be considered as a problem in statics. As cable systems are close siblings of trusses (cables, however, can carry tensile forces only), in our study we refer to equilibrium equation similar to those known from the theory of the latter. In particular, the paper regards designing pre-tensioned cable systems, with a goal to make them kinematically stable and such that the weight of so designed system is lowest possible. Unlike in typical topology optimization problems, our goal is not to optimize the structural layout against a particular applied load. However, our method uses much the same pattern. First, we formulate the variational problem of form-finding and next we describe the corresponding iterative numerical procedure for determining the optimum location of nodes of the cable system mesh. We base our study on the concept of force density which is a ratio of an axial force in cable segment to its length.

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Authors and Affiliations

Grzegorz Michał Dzierżanowski
Izabela Wójcik-Grząba
ORCID: ORCID
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Abstract

Hørbyebreen surged in the 19th or early 20th century, as suggested by geomorphological evidences and looped medial moraines. In this study, we investigate its wide−spread geometry changes and geodetic mass balance with 1960 contour lines, 1990 and 2009 digital elevation models, in order to define the present−day state of the glacier. We also study its thermal structure from ground−penetrating radar data. Little is known about the glacier behaviour in the first part of the 20th century, but from its surge maximum until 1960 it has been retreating and losing its area. In the period 1960–1990, fast frontal thinning (2–3 m a −1 ) and a slow mass build−up in the higher zones (~0.15 m a −1 ) have been noted, resulting in generally negative mass balance (−0.40 ± 0.07 m w. eq. a −1 ). In the last studied period 1990–2009, the glacier showed an acceleration of mass loss (−0.64 m ± 0.07 w. eq. a −1 ) and no build−up was observed anymore. We conclude that Hørbyebreen system under present climate will not surge anymore and relate this behaviour to a considerable increase in summer temperature on Svalbard after 1990. Radar soundings indicate that the studied glacial system is polythermal, with temperate ice below 100–130 m depth. It has therefore not (or not yet) switched to cold−bedded, as has been suggested in previous works for some small Svalbard surge−type glaciers in a negative mass balance mode.
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Authors and Affiliations

Jakub Małecki
Samuel Faucherre
Mateusz C. Strzelecki

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