3,066 research outputs found
Electrical conductivity cell and method for fabricating the same
A flask having a threaded neck and a cap adapted for threaded engagement on the neck are used. A laminated disc between the cap and the neck forms a gas tight seal and the cap has a central opening that exposes a medial region of the disc. Piercing the disc through the opening are two electrodes, the inner ends of which contact the sample within the flask and the outer ends of which can be connected to test equipment. Cylindric glass tubes are fitted over the external portion of the electrodes to provide physical support and silicone rubber or a similar material serves to retain the glass cylinders in place and form a gas tight seal between the cylinders and the electrodes. Shrinkable tubing is shrunk over the glass tubes to afford further mechanical support and sealing. A final relatively large diameter shrinkable tube is shrunk over both electrodes and their associated glass cylinders. The support and sealing means for the electrodes is confined to a limited portion of the medial region of the disc so that the remainder of such region can be punctured by a hollow needle to introduce a test sample within the flask
Shock waves in transonic channel flows at moderate Reynolds numbers
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76375/1/AIAA-9312-844.pd
Ion-Size Effect at the Surface of a Silica Hydrosol
The author used synchrotron x-ray reflectivity to study the ion-size effect
for alkali ions (Na, K, Rb, and Cs), with densities as high as
m, suspended above the surface of a
colloidal solution of silica nanoparticles in the field generated by the
surface electric-double layer. According to the data, large alkali ions
preferentially accumulate at the sol's surface replacing smaller ions, a
finding that qualitatively agrees with the dependence of the Kharkats-Ulstrup
single-ion electrostatic free energy on the ion's radius.Comment: 17 pages, 4 figure
Correlations of the elements of the neutrino mass matrix
Assuming Majorana nature of neutrinos, we re-investigate, in the light of the
recent measurement of the reactor mixing angle, the allowed ranges for the
absolute values of the elements of the neutrino mass matrix in the basis where
the charged-lepton mass matrix is diagonal. Apart from the derivation of upper
and lower bounds on the values of the matrix elements, we also study their
correlations. Moreover, we analyse the sensitivity of bounds and correlations
to the global fit results of the neutrino oscillation parameters which are
available in the literature.Comment: 37 pages, 146 figures, minor corrections, 17 additional figures,
version for publication in JHE
Detecting Hidden Differences via Permutation Symmetries
We present a method for describing and characterizing the state of N
particles that may be distinguishable in principle but not in practice due to
experimental limitations. The technique relies upon a careful treatment of the
exchange symmetry of the state among experimentally accessible and
experimentally inaccessible degrees of freedom. The approach we present allows
a new formalisation of the notion of indistinguishability and can be
implemented easily using currently available experimental techniques. Our work
is of direct relevance to current experiments in quantum optics, for which we
provide a specific implementation.Comment: 8 pages, 1 figur
Line tension and structure of smectic liquid crystal multilayers at the air-water interface
At the air/water interface, 4,-8-alkyl[1,1,-biphenyl]-4-carbonitrile (8CB)
domains with different thicknesses coexist in the same Langmuir film, as
multiple bilayers on a monolayer. The edge dislocation at the domain boundary
leads to line tension, which determines the domain shape and dynamics. By
observing the domain relaxation process starting from small distortions, we
find that the line tension is linearly dependent on the thickness difference
between the coexisting phases in the film. Comparisons with theoretical
treatments in the literature suggest that the edge dislocation at the boundary
locates near the center of the film, which means that the 8CB multilayers are
almost symmetric with respect to the air/water interface.Comment: 21 pages, 6 figure
Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters
We present the results of a global neutrino oscillation data analysis within
the three-flavour framework. We include latest results from the MINOS
long-baseline experiment (including electron neutrino appearance as well as
anti-neutrino data), updating all relevant solar (SK II+III), atmospheric (SK
I+II+III) and reactor (KamLAND) data. Furthermore, we include a recent
re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These
results have important consequences for the analysis of reactor experiments and
in particular for the status of the mixing angle . In our
recommended default analysis we find from the global fit that the hint for
non-zero remains weak, at 1.8 for both neutrino mass
hierarchy schemes. However, we discuss in detail the dependence of these
results on assumptions concerning the reactor neutrino analysis.Comment: 15 pages, 10 figures and 2 tables, v2: corrected version, main
conclusions unchanged, references adde
Transonic small-disturbance theory for lightly loaded cascades
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76863/1/AIAA-7841-736.pd
The Ammount of Interstellar Carbon Locked in Solid Hydrogenated Amorphous Carbon
We review the literature and present new experimental data to determine the
amount of carbon likely to be locked in form of solid hydrogenated amorphous
carbon (HAC) grains. We conclude on the basis of a thorough analysis of the
intrinsic strength of the C-H stretching band at 3.4 micron that between 10 and
80 ppM H of carbon is in the form of HAC grains. We show that it is necessary
to know the level of hydrogenation (H/C) of the interstellar HAC to determine
more precisely the amount of carbon it ties up. We present optical constants,
photoluminescence spectroscopy, and IR absorption spectroscopy for a particular
HAC sample that is shown to have a 3.4 micron absorption feature that is
quantatively consistent with that observed in the diffuse interstellar medium.Comment: This paper is 14 pages long with 5 figures and will appear in the 1
December 1999 issue of Ap
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