Effect of Pressure on the Viscosity of Water

Bett, K. E.; Cappi, J. B.

doi:10.1038/207620a0

Cited by 234 publications

(109 citation statements)

References 4 publications

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“…1B) are well fit by a model with fixed S and τ increasing with pressure. Apparently, the increase in τ with pressure does not simply reflect viscosity increases of the bulk solvent; at 20°C, the relative viscosity of water actually decreases slightly with pressure at low pressure (P ≤ 1 kbar) and increases by approximately 15% at 4 kbar (27). In addition, replacing water by D 2 O (viscosity 25% greater than water) (SI Text) or increasing the viscosity by a factor of 3 with sucrose has no effect on R1 internal motion (18).…”

Section: Resultsmentioning

confidence: 99%

High-pressure EPR reveals conformational equilibria and volumetric properties of spin-labeled proteins

McCoy

Hubbell

2011

Proc. Natl. Acad. Sci. U.S.A.

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Identifying equilibrium conformational exchange and characterizing conformational substates is essential for elucidating mechanisms of function in proteins. Site-directed spin labeling has previously been employed to detect conformational changes triggered by some event, but verifying conformational exchange at equilibrium is more challenging. Conformational exchange (microsecond-millisecond) is slow on the EPR time scale, and this proves to be an advantage in directly revealing the presence of multiple substates as distinguishable components in the EPR spectrum, allowing the direct determination of equilibrium constants and free energy differences. However, rotameric exchange of the spin label side chain can also give rise to multiple components in the EPR spectrum. Using spin-labeled mutants of T4 lysozyme, it is shown that high-pressure EPR can be used to: (i) demonstrate equilibrium between spectrally resolved states, (ii) aid in distinguishing conformational from rotameric exchange as the origin of the resolved states, and (iii) determine the relative partial molar volume (ΔV o ) and isothermal compressibility (Δβ T ) of conformational substates in two-component equilibria from the pressure dependence of the equilibrium constant. These volumetric properties provide insight into the structure of the substates. Finally, the pressure dependence of internal side-chain motion is interpreted in terms of volume fluctuations on the nanosecond time scale, the magnitude of which may reflect local backbone flexibility.P roteins undergo structural fluctuations that span a wide range of time scales. Among these motions are fast backbone fluctuations on the picosecond-nanosecond time scale and slower conformational fluctuations on the microsecond and longer time scale (1-3). Molecular flexibility on these time scales plays a central role in protein function (4). For example, in recognitionbinding sequences, dynamic disorder on the nanosecond-microsecond time scale may increase the rate of protein-protein interactions via a "fly casting" mechanism (5). An emerging disorder-to-order paradigm for interaction (6) can also give rise to promiscuity in binding that increases the size of the "interactome."Regulation of protein function is often linked to a conformational switch triggered by an interaction with a chemical or physical signal. One mechanistic interpretation of this event is provided by a "preequilibrium" model, which posits that all possible conformations of a protein exist at equilibrium with populations proportional to their relative energies (7). The exchange ("hopping") event between different conformers is characterized by lifetimes in the microsecond-millisecond range (1, 2, 8). In this model, a conformational switch is viewed as a shift in the relative populations of existing conformational states rather than the creation of a new state.To evaluate the above models and elucidate molecular mechanisms of protein function, it is essential to have experimental means for identifying dynamically disordered sequenc...

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Section: Resultsmentioning

confidence: 99%

High-pressure EPR reveals conformational equilibria and volumetric properties of spin-labeled proteins

McCoy

Hubbell

2011

Proc. Natl. Acad. Sci. U.S.A.

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“…The Debye equation, however, suggests that W p should be proportional to the viscosity q of the solvent at a given temperature (14). Water is an anomalous fluid in that q is only slightly affected (it is actually decreased and then increased (15,16)) by rising pressure under the conditions of our experiments (3.0°C, 0.1-215 MPa), so that the pressure dependences of Av and W p in aqueous solutions can be safely neglected.…”

Section: Aqueous Solutions At Variable Pressurementioning

confidence: 99%

Pressure effects on the rate of electron transfer between tris(1,10-phenanthroline)iron(II) and -(III) in aqueous solution and in acetonitrile

Doine¹,

Swaddle²

1988

Can. J. Chem.

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HIDEO DOINE and THOMAS WILSON SWADDLE. Can. J. Chem. 66, 2763.Proton nrnr line-broadening experiments at ambient and elevated (to 215 MPa) pressures show that the rate of electron transfer between F e (~h e n )~~+ and Fe(phen)33+ as bisulfates in D20/D2S04 is represented by the activation parameters (at ionic strength I -0.4molkg-I) AH* = 1.6 ? 0.5kJmol-I, AS* = -102.2 ? 1.6 J K -~~o I -' , k(276K) = 1.31 x 107kgmol-Is-', and (at I -0.3 mol kg-' and a mean pressure of 100 MPa) AV* = -2.2 2 0.1 cm3 mol-I. For the same reaction of the perchlorate salts (total [Fe] 0.046-0.065 mol kg-') in CD3CN, AH* = 11.0 I+-1.0 kJ mol-I, AS* = -72.5 2 3.6 J K-I mol-I, k(277 K) = 8.0 X 106kg mol-I s-I, and AV* = -5.9 2 0.5 cm3 mol-l. For water as solvent, AV* is satisfactorily accounted for by a classical theory of the Stranks-Hush-Marcus type. Volumes of activation for electron self-exchange are shown to provide criteria for non-adiabaticity and for dominance of (non-aqueous) solvent reorganizatlon dynamics; on this basis, it is seen that neither of these factors is important in the title reactions.HIDEO DOINE et THOMAS WILSON SWADDLE. Can. J. Chem. 66, 2763.Des experiences d'klargissement de raies dans les spectres rmn du proton, effectuies a la pression ambiante et a des pressions allant jus u'i 215 MPa, permettent de demontrer que la vitesse de transfert d'Clectron, entre les ions Fe(phen)32+ et le 4 . . 0,l cm3 mol-'. Lorsque l'eau est le solvant, on peut facilement expliquer la valeur du AV* par une thCorie classique du type Stranks-Hush-Marcus. On dCmontre que les volumes d'activation pour l'auto-Cchange des electrons fournissent des critkres pour expliquer les propriCtCs non-adiabatiques ainsi la dominance de la dynamique de reorganisation des solvants non-aqueux; sur cette base, on peut comprendre pourquoi aucun de ces facteurs n'est important dans les reactions mentionnCes dans le titre.[Traduit par la revue]

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“…The dynamic viscosity of water is dependent on the pressure, as seen in Fig. 4 [26]. In the estimated range up to 350 MPa, it will be approximated by a constant value of…”

Section: Classical Theory Of Hydraulic Shock and Zhukovsky Formulamentioning

confidence: 99%

“…Figure 4 Graph showing the dependence of the dynamic viscosity of water on the pressure according to [26] VII. For the maximum velocity of v = 200 m/s, the Reynolds number gets the value of…”

Section: Classical Theory Of Hydraulic Shock and Zhukovsky Formulamentioning

confidence: 99%

Pulsed water jet generated by pulse multiplication

2016

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Original scientific paper First theoretical papers, summarizing the high mechanical energy cumulation when high-speed drops impact on the solid surface as a result of the water hammer effect, have been known since 1960's. Heymann has demonstrated that pressure maximum during the impact of a spherical drop of a liquid is several times higher than the presupposed maximum for the classical waterhammer effect. The mentioned maximum pressure exceeds the stagnation pressure of the continuous jet several times over. When developing devices for pulsed jet generation, a new generalization of the classical water hammer theory for high pressures has been introduced. Based on this a new patented principle of "pulse multiplication" has been formulated. The pulse multiplier is the source of high-pressure pulses with 100 % depth of modulation of discharge velocity of a liquid jet. It enables to significantly increase the jet disintegration effect without addition of abrasives.Keywords: high-pressure pulses; pulse intensifier; pulsed water jet; water hammer effect Pulsirajući vodeni mlaz dobiven multiplikacijom impulsaIzvorni znanstveni članak Prvi teorijski radovi, koji su opisivali stvaranje velike količine mehaničke energije kad kapljice velike brzine udare u čvrstu površinu kao rezultat hidrauličkog udara, poznati su još od 1960-tih. Heymann je pokazao da je maksimalni tlak kod udara loptaste kapljice tekučine nekoliko puta veći od pretpostavljenog maksimalnog u slučaju klasičnog hidrauličkog udara. Spomenuti maksimalni tlak nekoliko je puta veći od tlaka kontinuiranog mlaza u stanju mirovanja. Kod stvaranja uređaja za generiranje pulsirajućeg mlaza, za visoke je tlakove uvedena nova generalizacija klasične teorije hidrauličkog udara. Na tom je temelju zasnovan novi patentirani princip "multiplikacije impulsa". Multiplikator impulsa je izvor visokotlačnih impulsa sa 100 % dubinom modulacije izlazne brzine tekućeg mlaza. Omogućuje značajno povećanje dezintegracijskog učinka mlaza bez dodavanja abraziva.Ključne riječi: pojačavač impulsa; pulsirajući vodeni mlaz; rezultat hidrauličkog udara; visokotlačni impulsi

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Effect of Pressure on the Viscosity of Water

Cited by 234 publications

References 4 publications

High-pressure EPR reveals conformational equilibria and volumetric properties of spin-labeled proteins

High-pressure EPR reveals conformational equilibria and volumetric properties of spin-labeled proteins

Pressure effects on the rate of electron transfer between tris(1,10-phenanthroline)iron(II) and -(III) in aqueous solution and in acetonitrile

Pulsed water jet generated by pulse multiplication

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