cavitation and bubble dynamics christopher e brennen

... generally a malevolentprocess, and that the deleterious consequences can be divided into three categories.First, cavitation can cause damage to the material surfaces close to the area where thebubbles ... proves to be impossible, and the effortmust be redirected into minimizing the adverse consequences of the phenomenon.The second adverse effect of cavitation is that the performance of the pump, ... a higher impeller tip speed, D/2. However, as we shall see in the next chapter, the propensity for cavitation increases as a parameter called the cavitation number decreases, and the cavitation

Ngày tải lên: 17/02/2021, 19:28

... of the sphere near z0 is now determined by periodic solutions of the Reeb vector field X having periods T = |m(u, z0 )| Every sequence sk → ∞ possesses a subsequence denoted by the same letters ... is recalled in the appendix We visualize a finite energy sphere u in R × S by Figure R×P S3 P Figure The figure shows a finite energy sphere with one positive and two negative punctures We next ... nature as we shall see below where we strengthen the concept of finite energy foliation We should remark that there are other finite energy foliations for (S , λ0 , i) For example, the collection

Ngày tải lên: 05/03/2014, 23:20

... for the buoyancy forces and stratification effects under theBoussinesq approximation Moreover, and due to the shallowness of the oceansand the atmosphere, i.e., the depth of the fluid layer is very ... vectorto Γs , and T ∗ (x, y) is typical temperature distribution of the top surface of the ocean For simplicity we assume here that τ and T ∗ are time independent.However, the results presented ... instance, [19] and references therein) Such an argument, however, is not valid for the 3D Navier-Stokes equations because of the pressure term Remarkably, the pressure term is absent from equation (38)

Ngày tải lên: 06/03/2014, 08:21

... package The combined estimates were obtained by weighted regression, in which the weights were the inverse of the local variances, i.e.: using the ‘fixed effect model’ [14] Heterogeneity was checked ... chi-square test under the fixed effect hypothesis and, if heterogeneity was detected, the ‘random effect model’ was applied For the purposes of this analysis, heterogeneity was assumed to be present ... problem of these studies is that related with errors in the measurement of exposure, mainly due to differences between measurements from sta-tions and real exposure of each person in a given

Ngày tải lên: 06/03/2014, 19:20

... the lowest total energy and NOE violations smaller than 0.25 A˚ were selected after the final refinement in Me2SO The N-terminal and C-terminal regions exhibit conforma-tional heterogeneity (especially ... relationship between the amino-acid sequence and immune response has been extensively inves-tigated [2,5] Differences in the amino-acid sequence of MBP from various animal species have a significant effect ... chemical-shift reference Peptide concentra-tion was usually 4 mM, and the spectra were recorded at 277 K Trace amounts of NaN3 were added as a preservative NOESY experiments – determination of distance restraints

Ngày tải lên: 07/03/2014, 16:20

... the well-defined five helical regions R1 (B), R2 (C), and 15 N- 1 H heteronuclear NOE (D) values were used to obtain the ordered parameters (E), the internal correlation times (F), the exchange ... those of the15N-1H NOEs were obtained from the difference of two independent experiments The values of error were adjusted for the proper tensor2 analy-sis, by increasing of the errors from the ... XPCB–hHR23B, one between helix 2 and helix 3, and one between helix 3 and helix 4–5 These two trails were linked by a hydro-phobic linker patch between helix 2 and helix 3 (P296, Trang 6L298, L299, and

Ngày tải lên: 07/03/2014, 17:20

... student a master's degree However, the student can also choose to complete only the first year of the programme and receive a one-year master’s degree The programme starts with the autumn semester ... financial systems for their emergence and performance Another concentrates on the micro level with case studies The key elements of the entrepreneurial process are studied, such as the recognition ... of the field and deeper knowledge of certain parts of the field, together with insight into current research and development work; and – demonstrate deeper methodological knowledge in the field

Ngày tải lên: 08/03/2014, 05:20

... sub-cities, each having two kebeles and three kebeles from six semi-urban kebeles surrounding Nekemte town and within 10 km were randomly selected to be included in the study These eleven kebeles then, ... female parents were in-clude in the FGDs as we were interested to see the percep-tions of both parents and young people from their own perspectives Teachers and parents were included as they are ... grand parents, uncle, sister, brother etc. Trang 7Perceived parents’ responsiveness to SRHrelated questions Both male and female young people perceived that their parents are not positively responding

Ngày tải lên: 22/03/2014, 12:20

... the structure of the MC1ÆDNA complex has not yet been solved, relaxation measurements on the complex have been conducted (Fig S3) Besides six Pro residues, resonance overlap precluded the interpre-tation ... force field deficiencies and disagreement between experimental and MD order parameters [26] MD sim-ulations using three MD force fields (comprising amberff03) overestimate the flexibility of backbone ... were processed with nmrpipe [28], and analyzed with nmrview [29] Backbone and side chain resonance assignments were obtained from the stan-dard triple resonance experiments [30] reference Interproton

Ngày tải lên: 22/03/2014, 17:20

... lending and hence bank leverage, which, in the presence of entrepre-a leverentrepre-age constrentrepre-aint in the bentrepre-anking sector, requires entrepre-a further increentrepre-ase in the externentrepre-al ... to entrepreneurs Henceentrepreneurial leverage and thus EtRbKt+1 Rbt persistently decline and therefore the decline in investment, entrepreneurial consumption and GDP is attenuated relative to ... banks and depositors Therefore the leverage of both the borrowing entrepreneur and the bank lending to him affect the spread between the interest rate on loans and the risk free rate, i.e the external

Ngày tải lên: 22/03/2014, 21:20

... l’ensemble du secteur bancaire, même si les banques n’internalisent pas cet effet La réglementation, qui consiste en une limitation du levier financier, peut atténuer l’influence de cette externalité ... but differ in the amount of private benefits they deliver tothe entrepreneurs The private benefit probabilities are denoted by b it, where it is thesize of an entrepreneur’s project and b ∈ [B, ... the incentive to behave as agreed, that the funds contributed by thebanker and the household earn (market-determined) required rates of return, and that theloan size respects the maximum leverage

Ngày tải lên: 22/03/2014, 21:20

... pre-viously reported T brucei structure, intense positive peaks in the difference maps were observed near the active site and were modelled as metal ions Their identities and occupancy were determined ... complication of selectivity In this respect, enolase is not the best target because the para-site and host enzymes share 58% sequence identity Nevertheless, modelling showed that there are three particularly ... N-terminal Met of the natural sequence could be traced in each new structure, and these result from thrombin cleavage of the His-tag used in purification (see Experimental procedures) In the three inhibitor-bound

Ngày tải lên: 23/03/2014, 07:20

... surface, W170 is deeply embedded in the hydrophobic core created by helices E, F and H The order parameters of these side chains appear to be independent of this environmental context The large majority ... representation of the best structure selected as the clo-sest to the ensemble average The color code is the same as in (A) The binding loops are noted from I to IV, and the a-helices and some residue positions ... surfaces The internal dynamics of the protein backbone were determined by studying amide hydrogen⁄ deuterium exchange rates and 15N nuclear relaxation The two methods revealed a highly compact and

Ngày tải lên: 23/03/2014, 13:20

... is the temperature gradient evaluated at the comet surface For freefree and freebound transitions of electrons, the Rosseland mean free path is given by Here, m, is the electron mass, ni and ... case would mean directly over Asia and Europe comet is a “dirty snowball” and therefore provides considerable amounts of hydrogen and hence the deu- terium isotope As the comet entered the atmosphere, ... the aerial dynamics and the nuclear energy released in the gas cap of the meteor as it passed through the atmosphere The results obtained are consistent with the dominant phenomena observed for

Ngày tải lên: 23/03/2014, 13:20

... the 1990s redefinedthe high-tech sector: the reduction of defense spending by the federalgovernment after the end of the Cold War and the Internet revolution.Both have left clear marks on the ... “leaders become losers.” More recently,Christensen (1997) further developed this idea and called it the “innovator’s dilemma.” When Schumpeter talked about “the incessant gales of creativedestruction” ... rounding. regions, the service industries were the most active About 70 percent ofSilicon Valley new firms were engaged in professional or innovationservices The percentage is even higher in the other

Ngày tải lên: 29/03/2014, 23:20

... climbed with thermal activation is lowered Energies are all relative and so the end effect of this and the first mechanism are the same; loweringthe relative energy difference between reactants and ... and the last set of terms similarly represent the kinetic and potential energy for an environmental bath Here, s represents some coordinate that measures progress of the reaction (for example, ... of the coupling of the environmental mode to the reaction coordinate, and mk and xkgive the effective mass and frequency, respectively, of the environmental bath mode A discrete spectral density

Ngày tải lên: 31/03/2014, 23:20

... (2), will be referred to as the thermal term, and it will be seen that very different bubble dynamics can be expected depending on the magnitude of this term When the temperature difference is small, ... necessary to mention the effects of surface roughness and of the turbulence level in the flow The two effects are connected to some degree since roughness will affect the level of turbulence ... Chapter - Cavitation and Bubble Dynamics - Christopher E Brennen latent heat and critical temperature, the tensile strength is determined by weaknesses at points within the liquid Such weaknesses...

Ngày tải lên: 24/04/2014, 16:46

... create the bubble, and this implies work done on or by the system The pressure difference involved in this energy increment is the difference between the pressure inside and outside of the bubble ... Christopher Earls, 194 1Cavitation and bubble dynamics / Christopher Earls Brennen p.cm.—(Oxford engineering science series; 44) Includes bibliographical references and index Cavitation and bubble dynamics ... order of 10−5 m, the subsequent tension required to expand the bubble beyond the envelope of the surface is only of the order of a tenth of an atmosphere and hence quite within the realm of experimental...

Ngày tải lên: 11/06/2014, 10:33

... Chapter - Cavitation and Bubble Dynamics - Christopher E Brennen absence of the bubble Other forms have been suggested and the situation has recently been reviewed by Prosperetti and Lezzi (1986), ... the noise level at frequencies of about 5kHz and above The spectral peak between 5kHz and 10kHz corresponds closely to the expected natural frequencies of the nuclei present in the flow (see Section ... The speed of the reentrant jet, UJ, at the time it impacts the opposite surface of the bubble has been shown to be given by (3.9) where ξ is a constant and ∆p is the difference between the remote...

Ngày tải lên: 07/08/2014, 10:20

... attached cavitation began to be more extensive As the Reynolds number increased further, the bubbles would tend to trigger attached cavities over the entire wake of the bubble as seen in the lower ... showed that since the streamlines that encounter the lowpressure region are close to the surface and, therefore, close to the stagnation streamline, nuclei will experience large fluid accelerations ... traveling bubble cavitation; these models are described in Chapter An example of dense traveling bubble cavitation is included in Figure 7.6 Note that the bubbles seem to merge to form a single...

Ngày tải lên: 07/08/2014, 10:20