634 research outputs found
A Review of the Pinned Photodiode for CCD and CMOS Image Sensors
The pinned photodiode is the primary photodetector structure used in most CCD and CMOS image sensors. This paper reviews the development, physics, and technology of the pinned photodiode
The amalgamated duplication of a ring along a multiplicative-canonical ideal
After recalling briefly the main properties of the amalgamated duplication of
a ring along an ideal , denoted by R\JoinI, we restrict our attention
to the study of the properties of R\JoinI, when is a multiplicative
canonical ideal of \cite{hhp}. In particular, we study when every regular
fractional ideal of is divisorial
The electrorheology of suspensions consisting of Na-Fluorohectorite synthetic clay particles in silicon oil
Under application of an electric field greater than a triggering electric
field kV/mm, suspensions obtained by dispersing particles of the
synthetic clay fluoro-hectorite in a silicon oil, aggregate into chain- and/or
column-like structures parallel to the applied electric field. This
micro-structuring results in a transition in the suspensions' rheological
behavior, from a Newtonian-like behavior to a shear-thinning rheology with a
significant yield stress. This behavior is studied as a function of particle
volume fraction and strength of the applied electric field, . The steady
shear flow curves are observed to scale onto a master curve with respect to
, in a manner similar to what was recently found for suspensions of laponite
clay [42]. In the case of Na-fluorohectorite, the corresponding dynamic yield
stress is demonstrated to scale with respect to as a power law with an
exponent , while the static yield stress inferred from
constant shear stress tests exhibits a similar behavior with . The suspensions are also studied in the framework of thixotropic fluids:
the bifurcation in the rheology behavior when letting the system flow and
evolve under a constant applied shear stress is characterized, and a
bifurcation yield stress, estimated as the applied shear stress at which
viscosity bifurcation occurs, is measured to scale as with to 0.6. All measured yield stresses increase with the particle
fraction of the suspension. For the static yield stress, a scaling law
, with , is found. The results are found to be
reasonably consistent with each other. Their similarities with-, and
discrepancies to- results obtained on laponite-oil suspensions are discussed
High-Frequency Oscillations in a Solar Active Region observed with the Rapid Dual Imager
High-cadence, synchronized, multiwavelength optical observations of a solar
active region (NOAA 10794) are presented. The data were obtained with the Dunn
Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly
developed camera system : the Rapid Dual Imager. Wavelet analysis is undertaken
to search for intensity related oscillatory signatures, and periodicities
ranging from 20 to 370 s are found with significance levels exceeding 95%.
Observations in the H-alpha blue wing show more penumbral oscillatory phenomena
when compared to simultaneous G-band observations. The H-alpha oscillations are
interpreted as the signatures of plasma motions with a mean velocity of 20
km/s. The strong oscillatory power over H-alpha blue-wing and G-band penumbral
bright grains is an indication of the Evershed flow with frequencies higher
than previously reported.Comment: 9 pages, 9 figure
Intercalation-enhanced electric polarization and chain formation of nano-layered particles
Microscopy observations show that suspensions of synthetic and natural
nano-layered smectite clay particles submitted to a strong external electric
field undergo a fast and extended structuring. This structuring results from
the interaction between induced electric dipoles, and is only possible for
particles with suitable polarization properties. Smectite clay colloids are
observed to be particularly suitable, in contrast to similar suspensions of a
non-swelling clay. Synchrotron X-ray scattering experiments provide the
orientation distributions for the particles. These distributions are understood
in terms of competing (i) homogenizing entropy and (ii) interaction between the
particles and the local electric field; they show that clay particles polarize
along their silica sheet. Furthermore, a change in the platelet separation
inside nano-layered particles occurs under application of the electric field,
indicating that intercalated ions and water molecules play a role in their
electric polarization. The resulting induced dipole is structurally attached to
the particle, and this causes particles to reorient and interact, resulting in
the observed macroscopic structuring. The macroscopic properties of these
electro-rheological smectite suspensions may be tuned by controlling the nature
and quantity of the intercalated species, at the nanoscale.Comment: 7 pages, 5 figure
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