Exactly solvable PT\mathcal{PT}-symmetric models in two dimensions

Non-hermitian, $\mathcal{PT}$-symmetric Hamiltonians, experimentally realized in optical systems, accurately model the properties of open, bosonic systems with balanced, spatially separated gain and loss. We present a family of exactly solvable, two-dimensional, $\mathcal{PT}$ potentials for a non-relativistic particle confined in a circular geometry. We show that the $\mathcal{PT}$ symmetry threshold can be tuned by introducing a second gain-loss potential or its hermitian counterpart. Our results explicitly demonstrate that $\mathcal{PT}$ breaking in two dimensions has a rich phase diagram, with multiple re-entrant $\mathcal{PT}$ symmetric phases.Comment: 6 pages, 6 figure

Experimental study of two separating turbulent boundary layers

A detailed study of two strong adverse pressure gradient flows, one with a free-stream velocity of 35 m/sec, at throat (producing a Re sub theta of 27000 at detachment) and another with free-stream velocity of 22 m/sec, at throat (producing a Re sub theta of 19000 at detachment) is presented. In these examples flows separate slowly and reattach very rapidly over a very short distance in a streamwise direction. In the backflow region, there appears to be a semi-logarithmically flat region in the streamwise fluctuating velocity component, u', which spreads over a definite range of y/delta. In power spectra, the flow variables phi sub upsilon upsilon (kappa sub 1 delta)/ -uv bar sub max vs. kappa sub 1 delta forms a unique set of scaling parameters for adverse pressure gradient flows. Experimental results show good agreement with previous studies

Management practices in Australian healthcare: can NSW public hospitals do better?

© 2016, © Emerald Group Publishing Limited. Purpose – The purpose of this paper is to investigate the determinants of best management practices in an Australian state-run healthcare system, namely New South Wales (NSW), and studies the impact of a range of hospital factors in driving best management practices as a means of enhancing healthcare delivery. Design/methodology/approach – This study adapts a unique survey instrument globally tested to quantify the multi-dimensional nature of hospital management practices in 42 acute care public hospitals of NSW. The authors then analysed the role of hospital-specific characteristics in driving best management practices, namely hospital size (measured by the number of hospital beds, employees and doctors), level of skill and education, degree of hospital manager autonomy and organisational hierarchy. Findings – The findings of this study show the areas of strength and potential areas of improvement in NSW hospitals. The authors find a positive association between the adoption of better management practices and hospital size (measured by the number of hospital beds and employees), level of skills and education, degree of hospital manager autonomy and organisational hierarchy. However, hospital size as measured by the number of doctors did not have a statistically significant relationship. Practical implications – This paper is of interest to both hospital administrators, clinical doctors and healthcare policy-makers who want to improve and develop strategies for better management in the healthcare sector. Originality/value – This study provides an internationally comparable robust measure of management capability in public hospitals, and contributes to the evidence-base of management practices and performance in hospitals

Benchmarking management practices in Australian public healthcare

© 2016, © Emerald Group Publishing Limited. Purpose – The purpose of this paper is to investigate the quality of management practices of public hospitals in the Australian healthcare system, specifically those in the state-managed health systems of Queensland and New South Wales (NSW). Further, the authors assess the management practices of Queensland and NSW public hospitals jointly and globally benchmark against those in the health systems of seven other countries, namely, USA, UK, Sweden, France, Germany, Italy and Canada. Design/methodology/approach – In this study, the authors adapt the unique and globally deployed Bloom et al. (2009) survey instrument that uses a “double blind, double scored” methodology and an interview-based scoring grid to measure and internationally benchmark the management practices in Queensland and NSW public hospitals based on 21 management dimensions across four broad areas of management – operations, performance monitoring, targets and people management. Findings – The findings reveal the areas of strength and potential areas of improvement in the Queensland and NSW Health hospital management practices when compared with public hospitals in seven countries, namely, USA, UK, Sweden, France, Germany, Italy and Canada. Together, Queensland and NSW Health hospitals perform best in operations management followed by performance monitoring. While target management presents scope for improvement, people management is the sphere where these Australian hospitals lag the most. Practical implications – This paper is of interest to both hospital administrators and health care policy-makers aiming to lift management quality at the hospital level as well as at the institutional level, as a vehicle to consistently deliver sustainable high-quality health services. Originality/value – This study provides the first internationally comparable robust measure of management capability in Australian public hospitals, where hospitals are run independently by the state-run healthcare systems. Additionally, this research study contributes to the empirical evidence base on the quality of management practices in the Australian public healthcare systems of Queensland and NSW

Fish diversity of Laster stream, a major tributary of river Mandakini in Central Himalaya (India) with regard to altitude and habitat specificity of fishes

Laster stream is a major tributary of river Mandakini, which in turn is a major tributary of river Alaknanda. Stream traverses a distance of ~40 km before joining with river Mandakini at Suryaprayag (Tilwara) in Rudraprayag district (Uttarakhand), India. Present study reports existence of twenty one indigenous fish species belonging to eight genera, three families and two orders from the Laster stream. Schizothorax richardsonii (Cyprinidae family) was the dominating species followed by S. plagiostomus, Barilius sp., Tor sp., Noemacheilus sp., Pseudecheneis sp., Glyptothorax sp. The distribution pattern (diversity and abundance) of these species had negative co-relation with the increase in stream altitude. Habitat conditions in the stream varied considerably from headwater to main stream. Present study also describes the habitat specificity of fish assemblage. Maximum species diversity (18 species) was recorded from pool habitat and was the most preferred habitat. Least species diversity (09 species) was recorded from cascade habitat. Riffle and rapid habitat recorded no difference in species diversity

Synthesis, photoluminescence and electrochemical properties of 2,7-diarylfluorene derivatives

A new class of highly fluorescent 9,9'-bis-(alkyl)-2,7-diarylfluorene having electron withdrawing or electron donating groups on the p-phenyl positions were synthesized and characterized. The highly luminescent fluorene derivatives, 1-6 showed blue emission (376-416 nm), narrow FWHM (~50 nm), high quantum yield (ΦF=0·12-0·87) and short fluorescence lifetimes, τF=0·23-1·14 ns. The HOMO levels of 9,9'-bis-(alkyl)-fluorene were tuned by the ρ-substituents at 2,7-phenyl group. Hammett correlation with EHOMO of these new molecules provides an effective tool to predict the HOMO level of similar molecules prior to the synthesis. These data indicate that they are useful as emitting materials for organic light emitting devices, OLEDs

Synthesis, photophysical and electrochemical properties of 2,8-diaryl-dibenzothiophene derivatives for organic electronics

A series of 2,8-p-diaryldibenzothiophene derivatives were synthesized and characterized. These molecules have electron withdrawing or electron donating groups at the para phenyl position, which alters the electronic properties of these derivatives. The quantum yield, fluorescence lifetime, singlet, triplet and EHOMO energy levels of these compounds were determined by fluorescence, phosphorescence and cyclic voltammetry. A plot of Hammett constants of the para substituents vs EHOMO revealed a linear relationship. The usefulness of these molecules in organic light emitting diodes, OLEDs is discussed vis-à-vis the energy levels and properties

Thorium(IV) and Zirconium(IV) Complexes of Oxygen Donor Ligands, Part XI. Oxozirconium(IV) Complexes of Hexamethyl Phosphoramide

A series of new complexes of the type ZrOX2(HMPA)n (n = 2 for X = N03, Cl, Br, I, BPh4, NCS; n = 6 for X = Cl04) are described. The coordination number of the zirconium was found to be 5 or 7 depending on the nature of anion X