Search results for "STEP"
showing 10 items of 509 documents
An Application of Iterative Identification and Control in the Robotics Field
2006
The plant model appropriate for designing the control strongly depends on the requirements. Simple models are enough to compute nondemanding controls. The parameters of well-defined structural models of flexible robot manipulators are difficult to determine because their effect is only visible if the manipulator is under strong actions or with high-frequency excitation. Thus, in this chapter, an iterative approach is suggested. This approach is applied to a one-degree-of-freedom flexible robot manipulator, first using some well-known models and then controlling a lab prototype. This approach can be used with a variety of control design and/or identification techniques.
Modelling of two step high spin⇌low spin transitions using the cluster variation method
1998
Abstract A thermodynamic description of high spin (HS)⇌low spin (LS) transition curves beyond the Bragg–Williams approximation is given using the Kikuchi cluster variation method (CVM). Transition curves of unusual behaviour (i.e. two step transition) are reproduced by short range interaction energies which are present in addition to long range elastic interaction between the spin changing molecules. The correlations in the distribution of the spin changing centers can be expressed analytically. They give rise to a reduced mixing entropy which was found experimentally in compounds with two step transitions.
An updated algorithm recommendation for the management of knee osteoarthritis from the European Society for Clinical and Economic Aspects of Osteopor…
2019
Objectives: The European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) sought to revisit the 2014 algorithm recommendations for knee osteoarthritis (OA), in light of recent efficacy and safety evidence, in order to develop an updated stepwise algorithm that provides practical guidance for the prescribing physician that is applicable in Europe and internationally. Methods: Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process, a summary of evidence document for each intervention in OA was provided to all members of an ESCEO working group, who were required to evaluate and vote on the streng…
Conservation genetics of endangered leaf-beetle Cheilotoma musciformis populations in Poland
2012
Steppe-like habitats in Europe are seriously threatened as a result of fragmentation and anthropogenic degradation, at least in western and central parts. Considering the dramatic loss of steppe-like habitats, the evaluation of genetic variation in populations of steppe species is of immediate importance if appropriate conservation measures are to be undertaken. In this paper, we examine the genetic diversity of the highly endangered populations of the leaf-beetle Cheilotoma musciformis, which inhabits only a limited area in south-central Poland, which is geographically isolated from the continuous range of this species. Both mitochondrial and nuclear markers show that the Polish population…
A novel approach to enhance mechanical properties during recycling of aluminum alloy scrap through friction stir consolidation
2021
Solid state recycling (SSR) is a new approach for making metals recycling more efficient with respect to remelting-based approaches. Friction stir consolidation (FSC) is a new solid-state process that is employed to recycle metallic scraps. Until now, a single-step FSC process was applied to recycled metal chips. During the single-step approach, critical processes parameters, especially processing time and rotational speed, are considered vital to control the quality and mechanical properties of the billet. However, the effectiveness of process parameters is highly restricted by challenging masses of recycling chips and machine competency. The present study first highlights the issues of th…
Controlling the position of anions relative to a pentafluorophenyl groupw
2012
The position of an anion above an electron-deficient arene can be controlled by the geometry of appended directing groups. Here a series of ammonium substituted pentafluorophenyl derivatives is investigated. The presented results are one step on the way to find the ideal structural features for an effective and superior receptor for anion–π studies.
Synthesis of Tripyreno[2,3,4-abc: 2,3,4-ghi: 2,3,4-mno][18]annulenes
2000
The title compounds were prepared in a multi-step synthesis in which primarily the pyrene building blocks were formed (1,2 11a,b). The final reaction step 11a,b 12a,b consisted of a threefold trans selective cyclocondensation process that generated the central 18-membered ring. Hexyloxy or dodecyloxy sidechains attached on the periphery led to the formation of liquid crystalline phases.
CIGS THIN FILM BY ONE-STEP ELECTRODEPOSITION FOR SOLAR CELLS
2013
In this work, we present a cost-effective technique to produce CIGS thin films for solar cells by means of a single-step electrodeposition. In fact, electrodeposition is known as an easy technique for building low cost materials for photovoltaic device processing. Morphological, structural and optical characterization of these films has been performed.
Multiple catenanes based on tetraloop derivatives of calix[4]arenes
2009
Abstract Four novel tetraarylurea calix[4]arenes ( 4a – d ) have been synthesized, substituted by ω-alkenyloxy residues in 3,5-positions of the arylurea residues. The eight alkenyl groups were pairwise connected by olefin metathesis and subsequent hydrogenation. The ring-closure reaction was carried out with heterodimers exclusively formed by 4 with a tetratosylurea calix[4]arene 1 , which serves as a template in this reaction step. The potential trans-cavity bridging is entirely suppressed in this way. Bis- and tetraloop calix[4]arenes cannot form dimers due to overlapping loops. However, they readily form heterodimers with open-chain tetraureas, as long as their urea residues can pass thr…
The Variability of the Photosynthetic Unit in Chlorella Fusca
1984
The concept of the photosynthetic unit (PSIT) was introduced by Gaffron and Wohl (1936) on the basis of Emerson and Arnold’s flash light experiments (1932). The PSU was defined as the minimum of chlorophyll molecules required for the evolution of one O2. Later on, the PSU was considered to be the complex of one reaction center and its appropriate antenna of light harvesting chlorophyll molecules. Assuming that there is an equal number of the PS I and PS II reaction centers the PSU was mostly expressed as Chl/P-700. However, recently it could be shown that the ratio of PS II/PS I is variable depending on the light conditions during growth (Kawamura et al., 1979; Myers, Graham, 1982). Further…