125 research outputs found
Fast accumulation of ions in a dual trap
Transporting charged particles between different traps has become an
important feature in high-precision spectroscopy experiments of different
types. In many experiments in atomic and molecular physics, the optical probing
of the ions is not carried out at the same location as the creation or state
preparation. In our double linear radio-frequency trap, we have implemented a
fast protocol allowing to shuttle large ion clouds very efficiently between
traps, in times shorter than a millisecond. Moreover, our shuttling protocol is
a one-way process, allowing to add ions to an existing cloud without loss of
the already trapped sample. This feature makes accumulation possible, resulting
in the creation of large ion clouds. Experimental results show, that ion clouds
of large size are reached with laser-cooling, however, the described mechanism
does not rely on any cooling process
Correcting symmetry imperfections in linear multipole traps
Multipole radio-frequency traps are central to collisional experiments in
cryogenic environments. They also offer possibilities to generate new type of
ion crystals topologies and in particular the potential to create infinite
1D/2D structures: ion rings and ion tubes. However, multipole traps have also
been shown to be very sensitive to geometrical misalignment of the trap rods,
leading to additional local trapping minima. The present work proposes a method
to correct non-ideal potentials, by modifying the applied radio-frequency
amplitudes for each trap rod. This approach is discussed for the octupole trap,
leading to the restitution of the ideal Mexican-Hat-like pseudo-potential,
expected in multipole traps. The goodness of the compensation method is
quantified in terms of the choice of the diagnosis area, the residual trapping
potential variations, the required adaptation of the applied radio-frequency
voltage amplitudes, and the impact on the trapped ion structures. Experimental
implementation for macroscopic multipole traps is also discussed, in order to
propose a diagnostic method with respect to the resolution and stability of the
trap drive. Using the proposed compensation technique, we discuss the
feasibility of generating a homogeneous ion ring crystal, which is a measure of
quality for the obtained potential well
Suivi du fonctionnement d’une toiture végétalisée stockante
International audienc
New Issues for Workers Safety in the Factory of the Future
Human in the factory is one of the main themes of the Factory of the Future, in this context the aim of this paper is to present the new issues for workers safety and the in-tegrated design concepts or methodologies which have to be taking into account. New paradigms come into being: the uncertainty of the demand in terms of products as well as production rate, product customization, integration product / service, the man-ufacturing processes are not fixed, so the manufacturing times cannot be foreseen, re-configuration of machine tools as manufacturing systems, space organization, auto-organization, planning …, new technologies are implemented: robots, plug and play devices, virtual / augmented reality, sensors, OPC standards, connected objects,… Several tasks are performed by the workers, the robots or in collaboration. The work-ers are place in the center of the Factory of the future but this concept introduce haz-ard events, problems of health and safety (physical or cognitive tasks, fatigue, stress, space or time organization, interfaces Human- robot, to take into account of the dif-ferent life situations…). So the aim of the paper is to present studies carrying out in order to propose to the machine or manufacturing systems designers as well as pro-duction managers structured methods, models, tools in order to get safe working sit-uations in the frame of the factory of the future paradigm
Is the bithiazole moiety of bleomycin a classical intercalator?
Bleomycin is a widespread anticancerous drug, the biological activity of which having been extensively studied. Its metal ion-chelating portion has been shown to cleave DNA whereas the role of the bithiazole moiety is still questionable. In order to elucidate this problem some 2', 4-disubstituted bithiazoles structurally related to the "tripeptide S" moiety of bleomycin were synthesized and their interaction with DNA was studied using delta Tm, fluorescence, EPR and viscometry techniques. The results of delta Tm and fluorescence quenching determinations were in favour of a binding of the bithiazole part by an intercalation process. Nevertheless, the use of the spin-label probes indicated only a partial intercalation of the ring between the base-pairs. Moreover, viscometry data which clearly exhibited a slight decrease of DNA length in the presence of bithiazole derivative led to the proposal of a binding model involving a partial insertion of a thiazole ring which wedges in between the bases at a bending point of DNA
Integrating User Information into Design Process to Solve Contradictions in Product Usage
This paper mainly focuses on improving the product performance by taking user factors into consideration during the engineering design phase. Firstly, the impact of design modification on the product lifecycle and the importance of the user in the engineering design process is discussed. Secondly, some reasons of why simply carrying out a socio-technical analysis hardly work on changing the design result are explained, what kinds of the data should be concerned by designer and how to collect data are discussed. Last, some helpful methods are introduced. Considering the costs of design modifications are usually very expensive and it may make the product (system) more complex, a novel idea is proposed, which to generate a user manual by analyzing the interaction between product behavior and user behavior during the early design stage to help designer to minimize the possibility of design modification after prototyping phase
- …