4,409 research outputs found
An Effective CIP Procedure for Removing Dairy Protein Based Deposit – A Laboratory Investigation
In this paper, examples of using an in-situ electrochemical cleaning technique are illustrated. It can be shown that while using the standard chemical for cleaning in the dairy industry, the application of the in-situ electrochemical method is very effective in removing the dairy protein based fouling deposits. Both the gel protocol developed earlier and the real fouling procedure have been used to evaluate the effectiveness of the new method
Analytic solutions of relativistic dissipative spin hydrodynamics with radial expansion in Gubser flow
We have derived the analytic solutions of dissipative relativistic spin
hydrodynamics with Gubser expansion. Following the standard strategy of
deriving the solutions in a Gubser flow, we take the Weyl rescaling and obtain
the energy-momentum and angular momentum conversation equations in the
space-time. We then derive the analytic solutions of
spin density, spin potential and other thermodynamic in
space-time and transform them back into Minkowski
space-time . In the Minkowski space-time, the spin density
and spin potential including the information of radial expansion decay as and in large limit, with
being proper time and being the characteristic length of the system,
respectively. Moreover, we observe the non-vanishing spin corrections to the
energy density and other dissipative terms in the Belinfante form of
dissipative spin hydrodynamics. Our results can also be used as test beds for
future simulations of relativistic dissipative spin hydrodynamics.Comment: 28 pages; 1 table and 1 figure are adde
Causality and stability analysis for the minimal causal spin hydrodynamics
We perform the linear analysis of causality and stability for a minimal
extended spin hydrodynamics up to second order of the gradient expansion. The
first order spin hydrodynamics, with a rank-3 spin tensor being antisymmetric
for only the last two indices, are proved to be acausal and unstable. We then
consider the minimal causal spin hydrodynamics up to second order of the
gradient expansion. We derive the necessary causality and stability conditions
for this minimal causal spin hydrodynamics. Interestingly, the satisfaction of
the stability conditions relies on the equations of state for the spin density
and chemical potentials. Moreover, different with the conventional relativistic
dissipative hydrodynamics, the stability of the theory seems to be broken at
the finite wave-vector when the stability conditions are fulfilled at small and
large wave-vector limits. It implies that the behavior in small and large
wave-vector limits may be insufficient to determine the stability conditions
for spin hydrodynamics in linear mode analysis.Comment: 45 pages, 2 figures, typos corrected, published versio
Bridge helix bending promotes RNA polymerase II backtracking through a critical and conserved threonine residue.
The dynamics of the RNA polymerase II (Pol II) backtracking process is poorly understood. We built a Markov State Model from extensive molecular dynamics simulations to identify metastable intermediate states and the dynamics of backtracking at atomistic detail. Our results reveal that Pol II backtracking occurs in a stepwise mode where two intermediate states are involved. We find that the continuous bending motion of the Bridge helix (BH) serves as a critical checkpoint, using the highly conserved BH residue T831 as a sensing probe for the 3'-terminal base paring of RNA:DNA hybrid. If the base pair is mismatched, BH bending can promote the RNA 3'-end nucleotide into a frayed state that further leads to the backtracked state. These computational observations are validated by site-directed mutagenesis and transcript cleavage assays, and provide insights into the key factors that regulate the preferences of the backward translocation
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