Formation of capillary bridges in AFM-like geometry

We discuss the phase diagram of fluid confined in AFM-like geometry. It combines the properties of capillary condensation and complete filling of a wedge.Comment: 9 pages, 7 figure

The influence of line tension on the formation of liquid bridges

The formation of liquid bridges between a planar and conical substrates is analyzed macroscopically taking into account the line tension. Depending on the value of the line tension coefficient \tau and geometric parameters of the system one observes two different scenarios of liquid bridge formation upon changing the fluid state along the bulk liquid-vapor coexistence. For \tau > \tau * (\tau * < 0) there is a first-order transition to a state with infinitely thick liquid bridge. For \tau < \tau * the scenario consists of two steps: first there is a first-order transition to a state with liquid bridge of finite thickness which upon further increase of temperature is followed by continuous growth of the thickness of the bridge to infinity. In addition to constructing the relevant phase diagram we examine the dependence of the width of the bridge on thermodynamic and geometric parameters of the system.Comment: 4 pages, 5 figure

The British house magazine 1945 to 2015: The creation of family, organisation and markets

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record This article examines the history of British house magazines from 1945 to 2015. It discusses their content, audience and function within companies. From tools of internal public relations, house magazines switched to being used as mediums of industrial relations in the 1960s and 1970s, and by the late 1980s were increasingly applied to the creation of corporate identity, organisational culture and internal marketing. They were also forced to accommodate the rise of internal communications and electronic media. The article discusses the rise and relative decline of the British house magazine, and ends by asking whether it has a future.British CouncilLeverhulme Trus

An analysis of factors affecting project performance in industrial buildings with particular reference to design build contracts

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The problem of determining an appropriate procurement form for the management of a construction project has been surrounded by controversy and strongly held opinions. The work reported here attempts to indicate some rational basis for choice in this decision by identifying those factors which significantly affect project performance, with particular reference to the distinctions between design build and traditional procurement forms. Two basic propositions are addressed by the work. The former is that design build forms perform better than traditional forms. This view is based on the conventional, construction industry view of the factors which affect performance. The latter is that contextual factors and the management and organisation of the construction process are the major determinants of project performance. This view stems from the application of management theory to the construction process and takes into account more and diverse variables than the conventional view. The factors which affect construction project performance are identified by reviewing three basic areas which are fundamental to the research. The first is the construction process and the way it has been treated and analysed in the past, which has been based around the traditional form of organisation. The second is the perceptions held concerning the design build process and how this procurement form has developed over recent years. A taxonomy of design build organisations is presented. Finally, the literature concerning project management, in general and specifically applied to the construction process, is reviewed and those factors which have been identified as affecting project performance identified. Following on is a review of performance measures which have previously been adopted. Based on this review a number of measures are chosen to compare performance (a mixture of objective and subjective measures). The foregoing leads to the situation where two research models are proposed and tested, by the formulation of related hypotheses, in two separate phases of the research process. A sample of 47 projects was used in the initial phase of the work and this was followed up by 27 detailed case studies in the subsequent phase. The data collected are analysed using partial correlation analysis as the principal analytic tool and the main results are reported below. The primary conclusion to be drawn is that procurement form is not a good predictor of performance. In general, the management, organisation and contextual variables are found to be more strongly associated with performance. Specifically, increased client complexity and dependence are found to be associated with reduced performance, as are increased project complexity and uncertainty. Document certainty and completeness and the degree of competition in letting construction works are all factors found to affect performance. Familiarity and differentiation are organisational factors which are found to be strongly associated with performance. Finally, it is shown that different procurement forms can be located on a structure grid and that those organisations which are appropriately located are associated with higher levels of performance

Metastable liquid-liquid coexistence and density anomalies in a core-softened fluid

Linearly-sloped or `ramp' potentials belong to a class of core-softened models which possess a liquid-liquid critical point (LLCP) in addition to the usual liquid-gas critical point. Furthermore they exhibit thermodynamic anomalies in the density and compressibility, the nature of which may be akin to those occurring in water. Previous simulation studies of ramp potentials have focused on just one functional form, for which the LLCP is thermodynamically stable. In this work we construct a series of ramp potentials, which interpolate between this previously studied form and a ramp-based approximation to the Lennard-Jones (LJ) potential. By means of Monte Carlo simulation, we locate the LLCP, the first order high density liquid (HDL)-low density liquid (LDL) coexistence line, and the line of density maxima for a selection of potentials in the series. We observe that as the LJ limit is approached, the LLCP becomes metastable with respect to freezing into a hexagonal close packed crystalline solid. The qualitative nature of the phase behaviour in this regime shows a remarkable resemblance to that seen in simulation studies of accurate water models. Specifically, the density of the liquid phase exceeds that of the solid; the gradient of the metastable LDL-HDL line is negative in the pressure (p)-temperature (T) plane; while the line of density maxima in the p-T plane has a shape similar to that seen in water and extends well into the {\em stable} liquid region of the phase diagram. As such, our results lend weight to the `second critical point' hypothesis as an explanation for the anomalous behaviour of water.Comment: 7 pages, 8 figure

Dielectrophoresis model for the colossal electroresistance of phase-separated manganites

We propose a dielectrophoresis model for phase-separated manganites. Without increase of the fraction of metallic phase, an insulator-metal transition occurs when a uniform electric field applied across the system exceeds a threshold value. Driven by the dielectrophoretic force, the metallic clusters reconfigure themselves into stripes along the direction of electric field, leading to the filamentous percolation. This process, which is time-dependent, irreversible and anisotropic, is a probable origin of the colossal electroresistance in manganites.Comment: 4 pages, 5 figure

In-plane structure and ordering at liquid sodium surfaces and interfaces from ab initio molecular dynamics

Atoms at liquid metal surfaces are known to form layers parallel to the surface. We analyze the two-dimensional arrangement of atoms within such layers at the surface of liquid sodium, using ab initio molecular dynamics (MD) simulations based on density functional theory. Nearest neighbor distributions at the surface indicate mostly 5-fold coordination, though there are noticeable fractions of 4-fold and 6-fold coordinated atoms. Bond angle distributions suggest a movement toward the angles corresponding to a six-fold coordinated hexagonal arrangement of the atoms as the temperature is decreased towards the solidification point. We rationalize these results with a distorted hexagonal order at the surface, showing a mixture of regions of five and six-fold coordination. The liquid surface results are compared with classical MD simulations of the liquid surface, with similar effects appearing, and with ab initio MD simulations for a model solid-liquid interface, where a pronounced shift towards hexagonal ordering is observed as the temperature is lowered

[N]pT Monte Carlo Simulations of the Cluster-Crystal-Forming Penetrable Sphere Model

Certain models with purely repulsive pair interactions can form cluster crystals with multiply-occupied lattice sites. Simulating these models' equilibrium properties is, however, quite challenging. Here, we develop an expanded isothermal-isobaric $[N]pT$ ensemble that surmounts this problem by allowing both particle number and lattice spacing to fluctuate. We apply the method with a Monte Carlo simulation scheme to solve the phase diagram of a prototypical cluster-crystal former, the penetrable sphere model (PSM), and compare the results with earlier theoretical predictions. At high temperatures and densities, the equilibrium occupancy $n_{\mathrm{c}}^{\mathrm{eq}}$ of face-centered cubic (FCC) crystal increases linearly. At low temperatures, although $n_{\mathrm{c}}^{\mathrm{eq}}$ plateaus at integer values, the crystal behavior changes continuously with density. The previously ambiguous crossover around $T\sim0.1$ is resolved

Transient cavities and the excess chemical potentials of hard-spheroid solutes in dipolar hard sphere solvents

Monte Carlo computer simulations are used to study transient cavities and the solvation of hard-spheroid solutes in dipolar hard sphere solvents. The probability distribution of spheroidal cavities in the solvent is shown to be well described by a Gaussian function, and the variations of fit parameters with cavity elongation and solvent properties are analyzed. The excess chemical potentials of hard-spheroid solutes with aspect ratios $x$ in the range $1/5 \leq x \leq 5$, and with volumes between one and twenty times that of a solvent molecule, are presented. It is shown that for a given molecular volume and solvent dipole moment (or temperature) a spherical solute has the lowest excess chemical potential and hence the highest solubility, while a prolate solute with aspect ratio $x$ should be more soluble than an oblate solute with aspect ratio $1/x$. For a given solute molecule, the excess chemical potential increases with increasing temperature; this same trend is observed in the case of hydrophobic solvation. To help interpret the simulation results, comparison is made with a scaled-particle theory that requires prior knowledge of a solute-solvent interfacial tension and the pure-solvent equation of state, which parameters are obtained from simulation results for spherical solutes. The theory shows excellent agreement with simulation results over the whole range of solute elongations considered.Comment: 10 pages, 10 figure

A paediatric telecardiology service for district hospitals in south-east England: an observational study.

The attached article is a Publisher version of the final published version which may be accessed at the link below. Copyright © 2010 BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health. All rights reservedOBJECTIVES: To compare caseloads of new patients assessed by paediatric cardiologists face-to-face or during teleconferences, and assess NHS costs for the alternative referral arrangements. DESIGN: Prospective cohort study over 15 months. SETTING: Four district hospitals in south-east England and a London paediatric cardiology centre. PATIENTS: Babies and children. INTERVENTION: A telecardiology service introduced alongside outreach clinics. MEASUREMENTS: Clinical outcomes and mean NHS costs per patient. RESULTS: 266 new patients were studied: 75 had teleconsultations (19 of 42 newborns and 56 of 224 infants and children). Teleconsultation patients generally were younger (49% being under 1 year compared with 32% seen personally (p = 0.025)) and their symptoms were not as severe. A cardiac intervention was undertaken immediately or planned for five telemedicine patients (7%) and 30 conventional patients (16%). However, similar proportions of patients were discharged after being assessed (32% telemedicine and 39% conventional). During scheduled teleconferences the mean duration of time per patient in sessions involving real-time echocardiography was 14.4 min, and 8.5 min in sessions where pre-recorded videos were transmitted. Mean cost comparisons for telemedicine and face-to-face patients over 14-day and 6-month follow-up showed the telecardiology service to be cost-neutral for the three hospitals with infrequently-held outreach clinics (1519 UK pounds vs 1724 UK pounds respectively after 14 days). CONCLUSION: Paediatric cardiology centres with small cadres of specialists are under pressure to cope with ever-expanding caseloads of new patients with suspected anomalies. Innovative use of telecardiology alongside conventional outreach services should suitably, and economically, enhance access to these specialists.The Department of Health and the Charitable Funds Committee of the Royal Brompton and Harefield NHS Trust funded the project