Liquid bridging of cylindrical colloids in near-critical solvents

Within mean field theory, we investigate the bridging transition between a pair of parallel cylindrical colloids immersed in a binary liquid mixture as a solvent which is close to its critical consolute point $T_c$. We determine the universal scaling functions of the effective potential and of the force between the colloids. For a solvent which is at the critical concentration and close to $T_c$, we find that the critical Casimir force is the dominant interaction at close separations. This agrees very well with the corresponding Derjaguin approximation for the effective interaction between the two cylinders, while capillary forces originating from the extension of the liquid bridge turn out to be more important at large separations. In addition, we are able to infer from the wetting characteristics of the individual colloids the first-order transition of the liquid bridge connecting two colloidal particles to the ruptured state. While specific to cylindrical colloids, the results presented here provide also an outline for identifying critical Casimir forces acting on bridged colloidal particles as such, and for analyzing the bridging transition between them.Comment: 23 pages, 12 figure

An exploratory study to identify risk factors for the development of capecitabine-induced palmar plantar erythrodysesthesia (PPE)

Aims: to identify pre-treatment risk factors for the development of Palmar Plantar Erythrodysesthesia in participants receiving capecitabine monotherapy. Specifically the hypothesis that avoidance of activities that cause friction and pressure cause Palmar Plantar Erythrodysesthesia was tested. Background. Previous literature showed contradictory evidence on the subject of predictors of chemotherapy-induced Palmar Plantar Erythrodysesthesia. There is a lack of empirical evidence to support the theory that Palmar Plantar Erythrodysesthesia is caused by damage to the microcapillaries due to everyday activities that cause friction or pressure to the hands or feet. Design. Prospective epidemiological study of risk factors. Methods. Prospective data collection. All patients prior to commencing capecitabine monotherapy between 11 June 2009–31 December 2010, were offered recruitment into the study and followed up for six cycles of treatment (n = 174). Data were collected during semi-structured interviews, from participants’ diaries, physical examination of the hands and feet and review of notes. Data relating to activities that cause friction, pressure or heat were collected. Data were analysed using bivariate (chi-square and independent groups Student’s t) tests where each independent variable was analysed against Palmar Plantar Erythrodysesthesia. Results. The only variables that were associated with an increased risk of Palmar Plantar Erythrodysesthesia were a tendency to have warm hands and pre-existing inflammatory disease. Conclusions. This study gives no support for the hypothesis that avoidance of activities that cause friction and pressure cause Palmar Plantar Erythrodysesthesia

Thermal expansion and magnetostriction of pure and doped RAgSb2 (R = Y, Sm, La) single crystals

Data on temperature-dependent, anisotropic thermal expansion in pure and doped RAgSb2 (R = Y, Sm, La) single crystals are presented. Using the Ehrenfest relation and heat capacity measurements, uniaxial pressure derivatives for long range magnetic ordering and charge density wave transition temperatures are evaluated and compared with the results of the direct measurements under hydrostatic pressure. In-plane and c-axis pressure have opposite effect on the phase transitions in these materials, with in-plane effects being significantly weaker. Quantum oscillations in magnetostriction were observed for the three pure compounds, with the possible detection of new frequencies in SmAgSb2 and LaAgSb2. The uniaxial (along the c-axis) pressure derivatives of the dominant extreme orbits (beta) were evaluated for YAgSb2 and LaAgSb2

Topological Excitations in Spinor Bose-Einstein Condensates

We investigate the properties of skyrmion in the ferromagnetic state of spin-1 Bose-Einstein condensates by means of the mean-field theory and show that the size of skyrmion is fixed to the order of the healing length. It is shown that the interaction between two skyrmions with oppositely rotating spin textures is attractive when their separation is large, following a unique power-law behavior with a power of -7/2.Comment: 4 pages, 5 figure

Wave attenuation and dispersion due to floating ice covers

Experiments investigating the attenuation and dispersion of surface waves in a variety of ice covers are performed using a refrigerated wave flume. The ice conditions tested in the experiments cover naturally occurring combinations of continuous, fragmented, pancake and grease ice. Attenuation rates are shown to be a function of ice thickness, wave frequency, and the general rigidity of the ice cover. Dispersion changes were minor except for large wavelength increases when continuous covers were tested. Results are verified and compared with existing literature to show the extended range of investigation in terms of incident wave frequency and ice conditions

An Investigation Into Computerized Estimating Software Used In Accounting For Cost Estimates By Residential Builders

The purpose of this study was to investigate the utilization of information technology in the estimating functions, related to the scale of operations, by Pennsylvania’s home building contractors.  Firm size was examined as to its impact on three issues in construction cost estimating practices; type of estimating technology, whether or not the primary estimating function was computerized, and if computerized, the primary program used for the estimating functions by home builders.  Significant differences existed among firm sizes in the information technology used for estimating costs.  Secondly, significant differences existed among firm sizes as to the use of a computerized estimating system verses a manual estimating system.  Larger firms utilized more advanced technology.  However, the results revealed that there are not significant differences among firm sizes in the primary program used for estimating when a firm has a computerized estimating procedure.  Small firms that are computerized in many cases are taking advantage of the same software used by larger firms

Device-independent bounds for Hardy's experiment

In this Letter we compute an analogue of Tsirelson's bound for Hardy's test of nonlocality, that is, the maximum violation of locality constraints allowed by the quantum formalism, irrespective of the dimension of the system. The value is found to be the same as the one achievable already with two-qubit systems, and we show that only a very specific class of states can lead to such maximal value, thus highlighting Hardy's test as a device-independent self-test protocol for such states. By considering realistic constraints in Hardy's test, we also compute device-independent upper bounds on this violation and show that these bounds are saturated by two-qubit systems, thus showing that there is no advantage in using higher-dimensional systems in experimental implementations of such test.Comment: 4 pages, 2 figure

Galaxy Satellites and the Weak Equivalence Principle

Numerical simulations of the effect of a long-range scalar interaction (LRSI) acting only on nonbaryonic dark matter, with strength comparable to gravity, show patterns of disruption of satellites that can agree with what is seen in the Milky Way. This includes the symmetric Sagittarius stellar stream. The exception presented here to the Kesden and Kamionkowski demonstration that an LRSI tends to produce distinctly asymmetric streams follows if the LRSI is strong enough to separate the stars from the dark matter before tidal disruption of the stellar component, and if stars dominate the mass in the luminous part of the satellite. It requires that the Sgr galaxy now contains little dark matter, which may be consistent with the Sgr stellar velocity dispersion, for in the simulation the dispersion at pericenter exceeds virial. We present other examples of simulations in which a strong LRSI produces satellites with large mass-to-light ratio, as in Draco, or free streams of stars, which might be compared to "orphan" streams.Comment: 14 pages, accepted for publication in PR