4,409 research outputs found

    An Effective CIP Procedure for Removing Dairy Protein Based Deposit – A Laboratory Investigation

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    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

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    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 dS3×RdS_{3}\times\mathbb{R} space-time. We then derive the analytic solutions of spin density, spin potential and other thermodynamic in dS3×RdS_{3}\times\mathbb{R} space-time and transform them back into Minkowski space-time R3,1\mathbb{R}^{3,1}. In the Minkowski space-time, the spin density and spin potential including the information of radial expansion decay as L2τ1\sim L^{-2}\tau^{-1} and L2τ1/3\sim L^{-2}\tau^{-1/3} in large LL limit, with τ\tau being proper time and LL 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

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    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.

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    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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