5,385 research outputs found
Humanoid Robots at work: where are we ?
Launched by Elon Musk and its Optimus, we are witnessing a new race in which
many companies have already engaged. The objective it to put at work a new
generation of humanoid robots in demanding industrial environments within 2 or
3 years. Is this objective realistic ? The aim of this document and its main
contributions is to provide some hints by covering the following topics: First
an analysis of 12 companies based on eight criteria that will help us to
distinguish companies based on their maturity and approach to the market;
second as these humanoids are very complex systems we will provide an overview
of the technological challenges to be addressed; third when humanoids are
deployed at scale, Operation and Maintenance become critical and the we will
explore what is new with these complex machines; Finally Pilots are the last
step to test the feasibility of a new system before mass deployment. This is an
important step to test the maturity of a product and the strategy of the
humanoid supplier to address a market and two pragmatic approaches will be
discussed.Comment: 30 pages 16 figure
Artificially induced positronium oscillations in a two-sheeted spacetime: consequences on the observed decay processes
Following recent theoretical results, it is suggested that positronium (Ps)
might undergo spontaneous oscillations between two 4D spacetime sheets whenever
subjected to constant irrotational magnetic vector potentials. We show that
these oscillations that would come together with o-Ps/p-Ps oscillations should
have important consequences on Ps decay rates. Experimental setup and
conditions are also suggested for demonstrating in non accelerator experiments
this new invisible decay mode.Comment: 9 pages, 2 figures. Minor form correction. Accepted for publication
in Int. J. of Modern Physics
Matter localization and resonant deconfinement in a two-sheeted spacetime
In recent papers, a model of a two-sheeted spacetime M4XZ2 was introduced and
the quantum dynamics of massive fermions was studied in this framework. In the
present study, we show that the physical predictions of the model are perfectly
consistent with observations and most important, it can solve the puzzling
problem of the four-dimensional localization of the fermion species in
multidimensional spacetimes. It is demonstrated that fermion localization on
the sheets arises from the combination of the discrete bulk structure and
environmental interactions. The mechanism described in this paper can be seen
as an alternative to the domain wall localization arising in continuous five
dimensional spacetimes. Although tightly constrained, motions between the
sheets are, however, not completely prohibited. As an illustration, a resonant
mechanism through which fermion oscillations between the sheets might occur is
described.Comment: 9 pages, 1 figure. Published version. Accepted for publication in
Int. J. of Modern Physics
Resonant control of spin dynamics in ultracold quantum gases by microwave dressing
We study experimentally interaction-driven spin oscillations in optical
lattices in the presence of an off-resonant microwave field. We show that the
energy shift induced by this microwave field can be used to control the spin
oscillations by tuning the system either into resonance to achieve near-unity
contrast or far away from resonance to suppress the oscillations. Finally, we
propose a scheme based on this technique to create a flat sample with either
singly- or doubly-occupied sites, starting from an inhomogeneous Mott
insulator, where singly- and doubly-occupied sites coexist.Comment: 4 pages, 5 figure
DLI-CVD of TiO2–Cu antibacterial thin films: Growth and characterization
TiO2–Cu nanocomposite films were grown by pulsed direct liquid injection chemical vapor deposition (DLICVD) on stainless steel, silicon and glass substrates with the goal to produce bactericidal surfaces. Copper bis (2,2,6,6-tetramethyl-3,5-heptadionate), Cu(TMHD)2, and titanium tetra-iso-propoxide, TTIP, were used as metalorganic precursors. Liquid solutions of these compounds in xylene were injected in a flash vaporization chamber connected to a cold wall MOCVD reactor. The deposition temperature was typically 683 K and the total pressure was 800 Pa. The copper content of the layers was controlled by the mole fraction of Cu (TMHD)2 which was adjusted by the injection parameters (injection frequency and concentration of the starting solution). The chemical, structural and physical characteristics of the films were investigated by XRD, XPS, FEG-SEM and TEM. Copper is incorporated as metal particles with a relatively large size distribution ranging from 20 to 400 nm (with a large majority in 20–100 nm) depending on the copper content of the films. The influence of the growth conditions on the structural features and the antibacterial properties of the thin films are reported and discussed
Recommended from our members
A new, substituted palladacycle for ppm level Pd-catalyzed Suzuki-Miyaura cross couplings in water.
A newly engineered palladacycle that contains substituents on the biphenyl rings along with the ligand HandaPhos is especially well-matched to an aqueous micellar medium, enabling valued Suzuki-Miyaura couplings to be run not only in water under mild conditions, but at 300 ppm of Pd catalyst. This general methodology has been applied to several targets in the pharmaceutical area. Multiple recyclings of the aqueous reaction mixture involving both the same as well as different coupling partners is demonstrated. Low temperature microscopy (cryo-TEM) indicates the nature and size of the particles acting as nanoreactors. Importantly, given the low loadings of Pd invested per reaction, ICP-MS analyses of residual palladium in the products shows levels to be expected that are well within FDA allowable limits
ADS-B Benefits to General Aviation and Barriers to Implementation
Automatic Dependent
Surveillance -‐
Broadcast (ADS-‐B)
will be
the
basis
of
the
future
surveillance
system
in
the
US.
To
achieve
benefit
from
ADS-‐B,
aircraft
have
to
be
equipped
with
ADS-‐B
avionics
across
all
stakeholders.
General
Aviation
(GA)
comprises
over
96%
of
the
active
aircraft
fleet
in
the
US
but
average
yearly
utilization
for
GA
aircraft
is
21
times
lower
than
that
of
commercial
aircraft.
Since
many
benefits
from
ADS-‐B
depend
on
aircraft
utilization,
concern
exists
that
ADS-‐B
does
not
provide
enough
user
benefit
to
GA,
possibly
resulting
in
delayed
acceptance
and
aircraft
equipage
with
ADS-‐B
avionics.
One
way
of
providing
user
benefits
and
thus
increasing
incentives
for
GA
users
to
equip
with
ADS-‐B
is
to
create
and
implement
ADS-‐B
applications
that
are
of
high
value
to
those
operators.
ADS-‐B
Surveillance
in
non-‐RADAR
airspace
and
ADS-‐B
based
Traffic
Situation
Awareness
(TSA)
are
identified
as
two
applications
that
are
expected
to
provide
significant
benefit
to
GA.
Both
applications
are
evaluated
and
possible
barriers
to
the
delivery
of
benefit
are
identified.
In
order
to
identify
where
TSA
would
be
most
beneficial,
ten
years’
worth
of
NTSB
mid-‐air
collision
reports
were
reviewed.
Ten
years
of
ASRS
and
NMACS
near
mid-‐air
collision
(MAC)
reports
were
also
reviewed.
The
analysis
revealed
that
aircraft
are
most
likely
to
encounter
each
other
in
the
airport
vicinity
–
specifically
in
the
pattern
(59%
of
MACs).
Current
Traffic
Awareness
systems
are
not
reliable
in
that
environment
due
to
insufficient
surveillance
data
quality.
Surveillance
data
from
ADS-‐B
,
however,
has
much
higher
resolution.
Therefore,
ADS-‐B
based
traffic
alerting
systems
are
expected
to
be
capable
of
providing
reliable
alerting
in
such
environments
and
would
thus
pose
a
significant
incentive
for
GA
to
equip
with
ADS-‐B.
An
analysis
of
the
current
availability
of
low
altitude
surveillance
over
the
continental
United
States
was
conducted
in
order
to
identify
where
ADS-‐B
Low
Altitude
Surveillance
would
be
beneficial.
Providing
low
altitude
surveillance
has
the
potential
to
improve
efficiency
during
IFR
conditions.
27
towered
airports
with
RADAR
floors
of
more
than
500ft
have
been
identified.
ADS-‐B
surveillance
in
those
locations
would
create
a
significant
benefit
locally.
Non-‐towered
airports
without
low
altitude
surveillance
are
more
common
(806
total).
ADS-‐B
surveillance
to
such
airports
has
the
potential
to
increase
airport
acceptance
rates
in
Instrument
Flight
weather
and
thus
providing
benefit
to
GA.
However,
in
addition
to
providing
surveillance,
additional
ATC
procedures
need
to
be
developed
to
take
advantage
of
such
ADS-‐B
surveillance.
The
new
procedures
would
allow
ATC
to
remain
in
radio
communication
with
aircraft
operating
at
non-‐towered
airports,
preventing
the
application
of
inefficient
procedural
control.FAA’s Surveillance
and Broadcast
Services Program
Office under contracts DTFA01-‐01-‐C-‐00030 and
DTFAWA-‐10-‐F-‐0008
Mantle flow beneath La Réunion hotspot track from SKS splitting
International audienceIf upper mantle anisotropy beneath fast-moving oceanic plates is expected to align the fast azimuths close to the plate motion directions, the upper mantle flow pattern beneath slow-moving oceanic plates will reflect the relative motion between the moving plate and the underlying large-scale convecting mantle. In addition to the non-correlation of the fast azimuths with the plate motion direction, the flow and anisotropy pattern may be locally perturbed by other factors such as the upwelling and the sublithospheric spreading of mantle plumes. Investigating such plume–lithosphere interaction is strongly dependent on the available seismological data, which are generally sparse in oceanic environment. In this study, we take the opportunity of recent temporary deployments of 15 seismic stations and 5 permanent stations on the Piton de la Fournaise volcano, the active locus of La Ré union hotspot and of 6 permanent stations installed along or close to its fossil track of about 3700 km in length, to analyze azimuthal anisotropy detected by SKS wave splitting and to decipher the various possible origins of anisotropy beneath the Western Indian Ocean. From about 150 good and fair splitting measurements and more than 1000 null splitting measurements, we attempt to distinguish between the influence of a local plume signature and large-scale mantle flow. The large-scale anisotropy pattern obtained at the SW-Indian Ocean island stations is well explained by plate motion relative to the deep mantle circulation. By contrast, stations on La Ré union Island show a complex signature characterized by numerous ''nulls'' and by fast split shear wave polarizations trending normal to the plate motion direction and obtained within a small backazimuthal window, that cannot be explained by either a single or two anisotropic layers. Despite the sparse spatial coverage which precludes a unique answer, we show that such pattern may be compatible with a simple model of sublithospheric spreading of La Ré union plume characterized by a conduit located at 100–200 km north of La Ré union Island. Anisotropy beneath the new GEOSCOPE station in Rodrigues Island does not appear to be influenced by La Ré union plume-spreading signature but is fully compatible with either a model of large-scale deep mantle convection pattern and/or with a channeled asthenospheric flow beneath the Rodrigues ridge.
Clock spectroscopy of interacting bosons in deep optical lattices
We report on high-resolution optical spectroscopy of interacting bosonic
Yb atoms in deep optical lattices with negligible tunneling. We prepare
Mott insulator phases with singly- and doubly-occupied isolated sites and probe
the atoms using an ultra-narrow "clock" transition. Atoms in singly-occupied
sites undergo long-lived Rabi oscillations. Atoms in doubly-occupied sites are
strongly affected by interatomic interactions, and we measure their inelastic
decay rates and energy shifts. We deduce from these measurements all relevant
collisional parameters involving both clock states, in particular the intra-
and inter-state scattering lengths
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