Explicit equations for leak rates through narrow cracks

Explicit equations to describe the leak rate of a single phase fluid through a narrow crack under a low pressure gradient have been developed and are presented. Four distinct flow regimes, which change with crack opening displacement, have been previously identified and are the basis of this model. The fluid flow is governed by the pressure gradient and the tortuosity of the crack, which is particularly important when the opening displacement is small. The equations have been developed by considering the pressure forces created when the fluid flows down an idealized zig-zag channel. The nature of the flow, and hence the governing equations, change as the crack aperture increases. The power of this approach is clearly seen when the flow rates predicted using this model are compared both to the flow rates obtained from computational fluid dynamics analysis and those found by experimentation. The agreement between these sets of data is good, showing that the major effects governing the flow rate have been identified and then accounted for

Visions in monochrome: Families, marriage and the individualisation thesis

This paper takes issue with the way in which the individualisation thesis – in which it is assumed that close relationships have become tenuous and fragile - has become so dominant in ‘new’ sociological theorising about family life. Although others have criticised this thesis, in this paper the main criticism derives from empirical research findings carried out with members of transnational families living in Britain whose values and practices do not fit easily with ideas of individualisation. It is argued that we need a much more complex and less linear notion of how families change across generations and in time

Real-space local polynomial basis for solid-state electronic-structure calculations: A finite-element approach

We present an approach to solid-state electronic-structure calculations based on the finite-element method. In this method, the basis functions are strictly local, piecewise polynomials. Because the basis is composed of polynomials, the method is completely general and its convergence can be controlled systematically. Because the basis functions are strictly local in real space, the method allows for variable resolution in real space; produces sparse, structured matrices, enabling the effective use of iterative solution methods; and is well suited to parallel implementation. The method thus combines the significant advantages of both real-space-grid and basis-oriented approaches and so promises to be particularly well suited for large, accurate ab initio calculations. We develop the theory of our approach in detail, discuss advantages and disadvantages, and report initial results, including the first fully three-dimensional electronic band structures calculated by the method.Comment: replacement: single spaced, included figures, added journal referenc

Lifetime distributions in the methods of non-equilibrium statistical operator and superstatistics

A family of non-equilibrium statistical operators is introduced which differ by the system age distribution over which the quasi-equilibrium (relevant) distribution is averaged. To describe the nonequilibrium states of a system we introduce a new thermodynamic parameter - the lifetime of a system. Superstatistics, introduced in works of Beck and Cohen [Physica A \textbf{322}, (2003), 267] as fluctuating quantities of intensive thermodynamical parameters, are obtained from the statistical distribution of lifetime (random time to the system degeneracy) considered as a thermodynamical parameter. It is suggested to set the mixing distribution of the fluctuating parameter in the superstatistics theory in the form of the piecewise continuous functions. The distribution of lifetime in such systems has different form on the different stages of evolution of the system. The account of the past stages of the evolution of a system can have a substantial impact on the non-equilibrium behaviour of the system in a present time moment.Comment: 18 page

Deformation effects in 56^{56}Ni nuclei produced in 28^{28}Si+28^{28}Si at 112 MeV

Velocity and energy spectra of the light charged particles (protons and $\alpha$-particles) emitted in the $^{28}$Si(E$_{lab}$ = 112 MeV) + $^{28}$Si reaction have been measured at the Strasbourg VIVITRON Tandem facility. The ICARE charged particle multidetector array was used to obtain exclusive spectra of the light particles in the angular range 15 - 150 degree and to determine the angular correlations of these particles with respect to the emission angles of the evaporation residues. The experimental data are analysed in the framework of the statistical model. The exclusive energy spectra of $\alpha$-particles emitted from the $^{28}$Si + $^{28}$Si compound system are generally well reproduced by Monte Carlo calculations using spin-dependent level densities. This spin dependence approach suggests the onset of large deformations at high spin. A re-analysis of previous $\alpha$-particle data from the $^{30}$Si + $^{30}$Si compound system, using the same spin-dependent parametrization, is also presented in the framework of a general discussion of the occurrence of large deformation effects in the A$_{CN}$ ~ 60 mass region.Comment: 25 pages, 6 figure

The effect of trepanning speed of laser drilled acute angled cooling holes on the high temperature low cycle corrosion fatigue performance of CMSX-4 at 850 °C

The effect of laser trepanning speed and, as a result, recast layer thickness on the high temperature corrosion fatigue behaviour of CMSX-4 superalloy acute angled holes was investigated. The experimental test results show that an increasing laser drilling speed caused a reduction in corrosion fatigue life by 35–50% at 850 °C, under low cycle fatigue regime. This reduction was found to correlate directly with the recast layer thickness and surface anomalies within the recast layer produced during the laser drilling process. Corrosion had a smaller effect on the overall life of the laser drilled specimens under the conditions tested. The results presented show that laser trepanning speed is influential in limiting the life performance of laser drilled components in service

Perineural liposomal bupivacaine for postoperative pain control in patients undergoing upper extremity orthopedic surgery: A prospective and randomized pilot study

Background: Upper extremity surgery is commonly performed in the ambulatory setting and is associated with moderate to severe postoperative pain. Methods: Patients scheduled for upper extremity orthopedic surgery with a peripheral nerve block were randomized to receive either an ultrasound-guided single-injection supraclavicular block or ultrasound-guided median, ulnar, and radial nerve blocks (forearm blocks) performed at the level of the mid to proximal forearm with liposomal bupivacaine (Exparel) combined with a short-acting supraclavicular block. A sham block was performed in an attempt to blind enrollees in the control group. We administered the EuroQol 5D-5L questionnaire preoperatively and on postoperative days 1-3 and considered the results the primary outcome of our investigation. Block procedure times, postanesthesia care unit (PACU) length of stay, instances of nausea/vomiting, need for narcotic administration, and patient satisfaction were also assessed. Results: We observed no significant differences in postoperative EuroQol scores between the 2 groups and no significant differences in patient demographics, PACU length of stay, or side effects in the PACU. In some instances, the short-acting supraclavicular block resolved in the PACU, and these patients reported higher pain scores and required titration of analgesics prior to discharge. Conclusion: Larger prospective studies are needed to determine the safety and efficacy of liposomal bupivacaine in patients undergoing upper extremity surgery. Liposomal bupivacaine is currently only approved for local anesthetic infiltration use