Search results for "Flash"
showing 10 items of 201 documents
Ethane-Bridged Zinc-Porphyrin Dimers in Langmuir-Shäfer Thin Films: Structural and Spectroscopic Properties
2006
This work reports on the structural and spectroscopic properties of ethane-bridged Zn porphyrin dimers (1) in Langmuir-Scha¨fer (LS) thin films by combining scanning force microscopy (SFM) with film balance, UV-vis absorption, fluorescence, and nanosecond laser flash photolysis measurements. Results show that depending on the surface pressure the Langmuir films of pure 1 can be arranged in two different condensed phases, whereas SFM of the LS films shows characteristic fractal networks constituted by nanoscopic aggregates. The spectral findings agree with a picture in which 1 is apparently present in the anti conformation but aggregated in a sort of H-type structure whose optical features r…
Light-Induced Protein-Matrix Uncoupling and Protein Relaxation in Dry Samples of Trehalose-Coated MbCO at Room Temperature
2005
In humid samples of trehalose-coated carboxy-myoglobin (MbCO), thermally driven conformational relaxation takes place after photodissociation of the carbon monoxide (CO) molecule at room temperature. In such samples, because of the extreme viscosity of the external matrix, photodissociated CO cannot diffuse out of the protein and explores the whole (proximal and distal side) heme pocket, experiencing averaged protein heme pocket structures, as a result of the presence of Brownian motions. At variance, in very dry samples, a lower portion of the photodissociated CO diffuses from the distal to the proximal heme pocket side probing in nonaveraged structures. We revisit here the flash photolysi…
Multisensory integration in hemianopia and unilateral spatial neglect: Evidence from the sound induced flash illusion.
2016
Recent neuropsychological evidence suggests that acquired brain lesions can, in some instances, abolish the ability to integrate inputs from different sensory modalities, disrupting multisensory perception. We explored the ability to perceive multisensory events, in particular the integrity of audio-visual processing in the temporal domain, in brain-damaged patients with visual field defects (VFD), or with unilateral spatial neglect (USN), by assessing their sensitivity to the 'Sound-Induced Flash Illusion' (SIFI). The study yielded two key findings. Firstly, the 'fission' illusion (namely, seeing multiple flashes when a single flash is paired with multiple sounds) is reduced in both left- …
Unconscious integration of multisensory bodily inputs in the peripersonal space shapes bodily self-consciousness
2017
International audience; Recent studies have highlighted the role of multisensory integration as a key mechanism of self-consciousness. In particular, integration of bodily signals within the peripersonal space (PPS) underlies the experience of the self in a body we own (self-identification) and that is experienced as occupying a specific location in space (self-location), two main components of bodily self-consciousness (BSC). Experiments investigating the effects of multisensory integration on BSC have typically employed supra-threshold sensory stimuli, neglecting the role of unconscious sensory signals in BSC, as tested in other consciousness research. Here, we used psychophysical techniq…
Trading activity and price impact in parallel markets: SETS vs. off-book market at the London Stock Exchange
2011
We empirically study the trading activity in the electronic on-book segment and in the dealership off-book segment of the London Stock Exchange, investigating separately the trading of active market members and of other market participants which are non-members. We find that (i) the volume distribution of off-book transactions has a significantly fatter tail than the one of on-book transactions, (ii) groups of members and non-members can be classified in categories according to their trading profile (iii) there is a strong anticorrelation between the daily inventory variation of a market member due to the on-book market transactions and inventory variation due to the off-book market transac…
Helium gas pressure cell for pressures up to 1 kbar (0.1 GPa) in conjunction with the cold head of a closed-cycle He refrigerator
1997
A helium gas pressure cell for pressures up to 1 kbar (0.1 GPa) has been developed in conjunction with a closed-cycle He refrigerator allowing variable temperatures between 15 and 300 K. Both cell and refrigerator are equipped with optical windows suitable for photophysical measurements, such as temperature- and pressure-dependent absorption spectroscopy or laser flash photolysis. Examples of measurements on iron(II) spin-crossover systems are given. In these compounds, comparatively small external pressures induce significant changes in the thermodynamic equilibrium as well as in the relaxation dynamics.
Self-Assembly of Polymer Blends and Nanoparticles through Rapid Solvent Exchange.
2019
Molecular dynamics simulations were performed to study the fabrication of polymeric colloids containing inorganic nanoparticles (NPs) via the flash nanoprecipitation (FNP) technique. During this process, a binary polymer blend, initially in a good solvent for the polymers, is rapidly mixed with NPs and a poor solvent for the polymers that is miscible with the good solvent. The simulations reveal that the polymers formed Janus particles with NPs distributed either on the surface of the aggregates, throughout their interior, or aligned at the interface between the two polymer domains, depending on the NP-polymer and NP-solvent interactions. The loading and surface density of NPs can be contro…
Dissimilar Al/steel Friction stir welding lap joints for automotive applications
2016
A widespread usage of aluminum alloys for the fabrication of car-body parts is conditional on the employment of appropriate welding methods, especially if dissimilar welding must be performed with automotive steel grades. Dissimilar welding of aluminum alloys and steel grades poses some issues concerning the formation of brittle intermetallic compounds, difference in physical and chemical properties of the parent metals, and poor wetting behavior of aluminum. Friction stir welding is considered to be a reasonable solution to obtain sound aluminum/steel joints. A study on the join quality of dissimilar lap joints of steel and aluminum alloy sheets after friction stir welding is proposed here…
Threshold Voltage Variability of NROM Memories After Exposure to Ionizing Radiation
2012
Threshold voltage (V-th) behavior of nitride readonly memories (NROMs) was studied after irradiation with photons (gamma-and X-rays), light and heavy ions. Both programmed and nonprogrammed single cells were investigated. The data suggest that two main physical phenomena are contributing to V-th variation and that the V-th loss and the variability can be modeled by a Weibull statistics with a shape parameter k similar to 2.2 regardless of the irradiation species and total dose. The same peculiarities were found in large memory arrays, confirming the results from single-cell studies but with significantly larger statistics. Hence, once the irradiation dose is known, the V-th loss distributio…
Nanocrystal memories for FLASH device applications
2004
Nanocrystals memory cells, in which the conventional polysilicon floating gate is replaced by an array of silicon nanocrystals, have been fabricated and characterized. Single cells and cell arrays of 1 Mb and 10 k have been realized by using a conventional 0.15 μm FLASH technology. Si nanocrystals are deposited on top of tunnel oxide by chemical vapor deposition. Properties of the memory cell have been investigated both for NAND and NOR applications in terms of program/erase window and programming times. Suitable program/erase threshold voltage window can be achieved with fast voltage pulses by adequate choice of tunnel and control dielectric. The feasibility of dual bit storage is also pro…