Transition to Film Boiling in Microgravity: Influence of Subcooling

The transition process to film pool boiling in microgravity is studied experimentally aboard the Chinese recoverable satellite SJ-8. A quasi-steady heating method is adopted, in which the heating voltage is controlled to increase exponentially with time. Small, primary bubbles are formed and slid on the surface, which coalesce with each other to form a large coalesced bubble. Two ways are observed for the transition from nucleate to film boiling at different subcoolings. At high subcooling, the coalesced bubble with a smooth surface grows slowly. It is then difficult for the coalesced bubble to cover the whole heater surface, resulting in a special region of transition boiling in which nucleate boiling and local dry areas can coexist. In contrast, strong oscillation of the coalesced bubble surface at low subcooling may cause rewetting of local dry areas and activation of more nucleate sites, resulting in an abrupt transition to film boiling.

Phase transition to color-flavor-locked matter and condensation of Goldstone bosons in neutron star matter

Deconfinement phase transition and condensation of Goldstone bosons in neutron star matter are investigated in a chiral hadronic model (also referred as to the FST model) for the hadronic phase (HP) and in the color-flavor-locked (CFL) quark model for the deconfined quark phase. It is shown that the hadronic-CFL mixed phase (MP) exists in the center of neutron stars with a small bag constant, while the CFL quark matter cannot appear in neutron stars when a large bag constant is taken. Color superconductivity softens the equation of state (EOS) and decreases the maximum mass of neutron stars compared with the unpaired quark matter. The K-0 condensation in the CFL phase has no remarkable contribution to the EOS and properties of neutron star matter. The EOS and the properties of neutron star matter are sensitive to the bag constant B, the strange quark mass m(s) and the color superconducting gap Delta. Increasing B and m(s) or decreasing Delta can stiffen the EOS which results in the larger maximum masses of neutron stars.

Piecewise Linear Models for the Quasiperiodic Transition to Chaos

We formulate and study analytically and computationally two families of piecewise linear degree one circle maps. These families offer the rare advantage of being non-trivial but essentially solvable models for the phenomenon of mode-locking and the quasi-periodic transition to chaos. For instance, for these families, we obtain complete solutions to several questions still largely unanswered for families of smooth circle maps. Our main results describe (1) the sets of maps in these families having some prescribed rotation interval; (2) the boundaries between zero and positive topological entropy and between zero length and non-zero length rotation interval; and (3) the structure and bifurcations of the attractors in one of these families. We discuss the interpretation of these maps as low-order spline approximations to the classic ``sine-circle'' map and examine more generally the implications of our results for the case of smooth circle maps. We also mention a possible connection to recent experiments on models of a driven Josephson junction.

Are gatekeepers to renal services referring patients equitably?

Objective: Patients with chronic kidney disease (CKD) benefit from specialist interventions to retard progression of renal failure and prevent cardiovascular events. Certain patient groups have poor access to specialist renal services when dialysis is required. This study used a population-based laboratory database to investigate access to and timeliness of referral to renal specialists relatively early in the course of the disease.

Methods: All tests for serum creatinine and haemoglobin (Hb) A1c in Northern Ireland in a two-year period (2001 and 2002) were retrieved for 345,441 adults. Of these, 16,856 patients had at least one serum creatinine level above 150 µmol/L in 2001 not deemed to be due to acute renal failure (crude prevalence 1.42%). This cohort was followed until the end of 2002 and the differences in the time to referral to a specialist were assessed using Cox's proportional hazards regression.

Results: Diabetic patients, older patients and those living in deprived areas were significantly more likely to have serum creatinine testing, compared with non-diabetic, younger and those living in more affluent areas. Delays in referral to renal specialists for patients with raised serum creatinine levels were significantly shorter among diabetic patients, women, younger individuals, those living in rural areas, those living close to renal centres and those living in deprived areas. Overall, only 19% of diabetic patients and 6% of non-diabetic patients who had CKD had seen a renal specialist within 12 months of their index creatinine test.

Conclusion: Contrary to other diseases, disadvantaged patients do not seem to be under-investigated for renal disease compared with their more affluent neighbours and are generally referred earlier for specialist assessment. However, the absolute rate of timely specialist assessment is low. Recent changes in referral criteria for CKD will result in more referrals and will have serious resource implications. Opportunities for health gain among patients with declining renal function are being missed, particularly among the old and those living furthest from specialist centres.

Is there a role for contemporary practices of askesis in supporting the transition to sustainable consumption?

An investigation of the potential role of contemporary practices of askesis (Foucault) in supporting the transition to sustainable consumption.

A Long and Winding Road to Employment?: Disabled young people in Northern Ireland making the transition to adulthood

This paper presents the findings of a qualitative research project that explores the experiences and aspirations of disabled young people in Northern Ireland as they make and deal with the transition to adulthood. The study involved young people with disabilities (n=76) in four areas of Northern Ireland, ensuring a geographical spread, an urban/rural mix and representation of both communities. Young people with learning disabilities were included as well as those with physical and/or sensory impairments. This paper focuses on those who were completing job training or work placements and examines the role of such schemes in assisting young people’s transition to adulthood. The research found that many young people had positive experiences of work placement and job training and that social interaction was important to them. Few young people, however, had made the actual transition from work placement or training to ‘real’ employment.

Biogeographical conditions, the transition to agriculture and long-run growth

We use new data on the timing of the transition to agriculture, developed by Putterman and Trainor (2006), to test the theory of Diamond (1997) and Olsson and Hibbs (2005) that an earlier transition is reflected in higher incomes today. Our results confirm the theory, even after controlling for institutional quality and other geographical factors. The date of transition is correlated with prehistoric biogeography (the availability of wild grasses and large domesticable animal species). The factors conducive to high per capita incomes today are good institutions, an early transition to agriculture, access to the sea and a low incidence of fatal malaria. Geographical influences have been at work in all of these proximate determinants of per capita income.