Nonlinear Elasticity, Fluctuations and Heterogeneity of Nematic Elastomers

Liquid crystal elastomers realize a fascinating new form of soft matter that is a composite of a conventional crosslinked polymer gel (rubber) and a liquid crystal. These {\em solid} liquid crystal amalgams, quite similarly to their (conventional, fluid) liquid crystal counterparts, can spontaneously partially break translational and/or orientational symmetries, accompanied by novel soft Goldstone modes. As a consequence, these materials can exhibit unconventional elasticity characterized by symmetry-enforced vanishing of some elastic moduli. Thus, a proper description of such solids requires an essential modification of the classical elasticity theory. In this work, we develop a {\em rotationally invariant}, {\em nonlinear} theory of elasticity for the nematic phase of ideal liquid crystal elastomers. We show that it is characterized by soft modes, corresponding to a combination of long wavelength shear deformations of the solid network and rotations of the nematic director field. We study thermal fluctuations of these soft modes in the presence of network heterogeneities and show that they lead to a large variety of anomalous elastic properties, such as singular length-scale dependent shear elastic moduli, a divergent elastic constant for splay distortion of the nematic director, long-scale incompressibility, universal Poisson ratios and a nonlinear stress-strain relation fo arbitrary small strains. These long-scale elastic properties are {\em universal}, controlled by a nontrivial zero-temperature fixed point and constitute a qualitative breakdown of the classical elasticity theory in nematic elastomers. Thus, nematic elastomers realize a stable ``critical phase'', characterized by universal power-law correlations, akin to a critical point of a continuous phase transition, but extending over an entire phase.Comment: 61 pages, 24 eps pages, submitted to Annals of Physic

Nominal Curvature Design of Circular HSC Columns Confined with Post-tensioned Steel Straps

This article proposes new parameters for the practical design of circular high-strength concrete (HSC) columns confined with an innovative Steel Strapping Tensioning Technique (SSTT) using a nominal curvature approach. Previous experimental research has proven the effectiveness of the SSTT at providing active confinement and enhancing the ductility of HSC columns, but to date no practical procedures are available so that the technique can be widely adopted in design practice. The proposed design approach is based on results from segmental analyses of slender SSTT-confined circular columns subjected to eccentric loads. The results obtained from the analyses are used to determine the variables governing the design of such columns. The use of the proposed design parameters predicts conservatively the capacity of small-scale slender HSC circular columns confined using the SSTT, and can be thus used in the practical design of reinforced concrete (RC) structures

Study on the One-Proton Halo Structure in 23^{23}Al

The Glauber theory has been used to investigate the reaction cross section of proton-rich nucleus $^{23}$Al. A core plus a proton structure is assumed for $^{23}$Al. HO-type density distribution is used for the core while the density distribution for the valence proton is calculated by solving the eigenvalue problem of Woods-Saxon potential. The transparency function in an analytical expression is obtained adopting multi-Gaussian expansion for the density distribution. Coulomb correction and finite-range interaction are introduced. This modified Glauber model is apt for halo nuclei. A dominate s-wave is suggested for the last proton in $^{23}$Al from our analysis which is possible in the RMF calculation.Comment: 4 pages, 4 figure

Privacy Unraveling Around Explicit HIV Status Disclosure Fields in the Online Geosocial Hookup App Grindr

mHealth applications ("apps") must be searched for and downloaded prior to use, creating a potential barrier to uptake. Integrating health interventions into existing online social environments removes this barrier. However, little is known about the effects of linking sensitive health information to existing online identities. Our qualitative analysis of online comments (n=192) explores the user views of an HIV intervention integrated into the geosocial hookup app Grindr. We find some HIV positive users report keeping their status private to reduce their stigma exposure, whilst others report publicly disclosing their status to avoid being stigmatised by others. Where users keep their status private, we find concerns that social assumptions may develop around these non-disclosures, creating a privacy unraveling effect which restricts disclosure choice. Using Peppet's four proposed limits to privacy unraveling, we develop a set of descriptive conceptual designs to explore the privacy respecting potential of these limits within this context and propose further research to address this privacy challenge

Clergy work-related satisfactions in parochial ministry: the influence of personality and churchmanship

The aim of this study was to test several hypotheses that clergy work-related satisfaction could be better explained by a multidimensional rather than a unidimensional model. A sample of 1071 male stipendiary parochial clergy in the Church of England completed the Clergy Role Inventory, together with the short-form Revised Eysenck Personality Questionnaire. Factor analysis of the Clergy Role Inventory identified five separate clergy roles: Religious Instruction, Administration, Statutory Duties (conducting marriages and funerals), Pastoral Care, and Role Extension (including extra-parochial activities). Respondents also provided an indication of their predispositions on the catholic-evangelical and liberal-conservative dimensions. The significant associations of the satisfactions derived from each of the roles with the demographic, personality, and churchmanship variables were numerous, varied, and, with few exceptions, small in magnitude. Separate hierarchical regressions for each of the five roles indicated that the proportion of total variance explained by churchmanship was, in general, at least as great as that explained by personality, and was greater for three roles: Religious Instruction, Statutory Duties, and Role Extension. It was concluded that clergy satisfactions derived from different roles are not uniform and that churchmanship is at least as important as personality in accounting for clergy work satisfaction

Magnesium intake, plasma C-peptide, and colorectal cancer incidence in US women: a 28-year follow-up study

Background: Laboratory studies suggest a possible role of magnesium intake in colorectal carcinogenesis but epidemiological evidence is inconclusive. Method: We tested magnesium–colorectal cancer hypothesis in the Nurses' Health Study, in which 85 924 women free of cancer in 1980 were followed until June 2008. Cox proportional hazards regression models were used to estimate multivariable relative risks (MV RRs, 95% confidence intervals). Results: In the age-adjusted model, magnesium intake was significantly inversely associated with colorectal cancer risk; the RRs from lowest to highest decile of total magnesium intake were 1.0 (ref), 0.93, 0.81, 0.72, 0.74, 0.77, 0.72, 0.75, 0.80, and 0.67 (Ptrend<0.001). However, in the MV model adjusted for known dietary and non-dietary risk factors for colorectal cancer, the association was significantly attenuated; the MV RRs were 1.0 (ref), 0.96, 0.85, 0.78, 0.82, 0.86, 0.84, 0.91, 1.02, and 0.93 (Ptrend=0.77). Similarly, magnesium intakes were significantly inversely associated with concentrations of plasma C-peptide in age-adjusted model (Ptrend=0.002) but not in multivariate-adjusted model (Ptrend=0.61). Results did not differ by subsite or modified by calcium intakes or body mass index. Conclusion: These prospective results do not support an independent association of magnesium intake with either colorectal cancer risk or plasma C-peptide levels in women

The Reform of Employee Compensation in China’s Industrial Enterprises

Although employee compensation reform in Chinese industrial sector has been discussed in the literature, the real changes in compensation system and pay practices have received insufficient attention and warrant further examination. This paper briefly reviews the pre- and post-reform compensation system, and reports the results of a survey of pay practices in the four major types of industrial enterprises in China. The research findings indicate that the type of enterprise ownership has little influence on general compensation practices, adoption of profit-sharing plans, and subsidy and allowance packages. In general, pay is linked more to individual performance and has become an important incentive to Chinese employees. However, differences are found across the enterprise types with regard to performance-related pay. Current pay practices are positively correlated to overall effectiveness of the enterprise