Search results for "Collision"
showing 10 items of 908 documents
''Active Collisions in Altered Gravity Reveal Eye-Hand Coordination Strategies''
2012
White, Olivier | Lefevre, Philippe | Wing, Alan M. | Bracewell, R. Martyn | Thonnard, Jean-Louis; International audience; ''Most object manipulation tasks involve a series of actions demarcated by mechanical contact events, and gaze is usually directed to the locations of these events as the task unfolds. Typically, gaze foveates the target 200 ms in advance of the contact. This strategy improves manual accuracy through visual feedback and the use of gaze-related signals to guide the hand/ object. Many studies have investigated eye-hand coordination in experimental and natural tasks; most of them highlighted a strong link between eye movements and hand or object kinematics. In this experime…
Collision Avoidance in Wake-Up Radio Enabled WSNs: Protocol and Performance Evaluation
2018
In wake-up radio (WuR) enabled wireless sensor networks (WSNs), the envisaged application scenarios are primarily targeted at low traffic load conditions. When applying WuR to medium or heavy traffic load scenarios, however, collisions among wake-up calls (WuCs) may happen, resulting in a lower packet delivery ratio (PDR). In this paper, we propose a media access control protocol for WuR- enabled WSN that is capable of avoiding WuC collisions by activating a contention-based collision avoidance mechanism for WuC transmissions. The performance of the proposed protocol is evaluated by a Markov chain based mathematical model and is compared with a WuR protocol that performs only clear channel as…
Optimization of Resolving Power, Fragmentation, and Mass Calibration in an Orbitrap Spectrometer for Analysis of 24 Pesticide Metabolites in Urine
2019
Mass spectrometer parameters such as Resolving Power, type of fragmentation, and mass calibration mode were optimized in the analysis of 24 pesticide metabolites in human urine using Ultra-High Pressure Liquid Chromatography coupled to Orbitrap High-Resolution Mass Spectrometer (UHPLC-HRMS). The best results were achieved with a Resolving Power of 25,000 FWHM and by applying Collision Induced Dissociation fragmentation mode (40 eV).
Fission barriers of doubly charged silver clusters
1999
The monomer evaporation energies and fission barriers of doubly charged silver cluster ions in the size range 9≤n≤25 are measured by collision induced dissociation. They are compared to the dissociation energies of singly charged silver clusters. A macroscopic liquid drop model combined with empirical microscopic corrections successfully describes the measured fission barriers.
Third-harmonic generation in the skin layer of a hot dense plasma
2003
The third-harmonic generation of a pump wave, resulting from the electron-ion collision frequency dependence on the electric field in the skin layer of a hot dense plasma is investigated. The relation of the current third harmonic with the high-frequency field in the skin layer is established for arbitrary ratios of the electron-ion collision frequency to the field frequency. For arbitrary ratios of these two frequencies, the field structure inside the skin layer is determined, and the field of the wave irradiated by the plasma at tripled frequency, too, is calculated. It has permitted us to find the explicit dependencies of the third-harmonic generation efficiency on the plasma and pump fi…
Electron Binding in a Superatom with a Repulsive Coulomb Barrier: The Case of [Ag44(SC6H3F2)30]4– in the Gas Phase
2020
The electron binding mechanism in [Ag44(SC6H3F2)30]4- (SC6H3F2 = 3,4-difluorobenzenethiolate) tetra-anion was studied by photoelectron spectroscopy (PES), collision-induced dissociation mass spectrometry (CID-MS), and density functional theory (DFT) computations. PES showed that [Ag44(SC6H3F2)30]4- is energetically metastable with respect to electron autodetachment {[Ag44(SC6H3F2)30]3- + e-} and features a repulsive Coulomb barrier (RCB) with a height of 2.7 eV. However, CID-MS revealed that [Ag44(SC6H3F2)30]4- does not release an electron upon collisional excitation but undergoes dissociation. DFT computations performed on the known structure of [Ag44(SC6H3F2)30]4- confirmed the negative a…
A new nature of microporous architecture with hierarchical porosity and membrane template via high strain rate collision
2019
Abstract This paper presents the formation of an unusual porous structure at Al/Al interface joined by magnetic pulse welding. The porous structure consists of a hierarchical microporous architecture with pore size of less than 2 µm that represents more than 80% over the whole area, in which 38% of them are sub-micron size pores. It also exhibits ultra-thin wall, sufficiently thin enough to behave as an electron-transparent material with a wall thickness of 50 nm. The formation of this porous structure is attributed to a cavitation process of a molten material in three stages including, (1) nucleation, (2) growth and coalescence and (3) solidification. Further analysis of this cavitation pr…
Non-linear optimization of track layouts in loop-sorting-systems
2013
Optimization used for enhancing geometric structures iswell known. Applying obstacles to the shape optimization problemis on the other hand not very common. It requires a fast contact search algorithmand an exact continuous formulation to solve the problem robustly. This paper focuses on combining shape optimization problemswith collision avoidance constraints by which a collision detection algorithmis presented. The presentedmethod is tested against the commercial loop-sorting-system used for sorting of medium sized items. The objective is to minimize price and footprint of the system whilemaintaining its functionality. Contact constraints are in this context important to include as variou…
Deformation history during chain building deduced by outcrop structural analysis: The case of the Sicilian fold-and-thrust belt (Central Mediterranea…
2015
Abstract The Sicilian fold-and-thrust belt is located in the central Mediterranean area, and it represents the south-eastern arcuate segment of the Apennine-Maghrebide orogen. The tectonic evolution of the Sicilian belt is documented after outcrop analysis of small-scale structural features carried out throughout the region. Results are consistent with the following four main deformation stages having affected the study area, from the oldest to the youngest: (i) multilayer weakening; (ii) folding-and-thrusting, (iii) extension, and (iv) renewed thrusting. The first deformation stage included three different substages (layer-parallel shortening, bed-parallel simple shear and fold nucleation)…