Birefringence compensation in double-core optical waveguides

A new concept for birefringence compensation in planar optical waveguides applying a double-core structure is introduced. It is demonstrated on waveguides fabricated in silicon oxynitride technology for applications in optical telecommunicatio

Experimental Determination of Dessicant Cooling System for Thermal Comfort

Desiccant cooling technology can be used to solve a variety of building comfort, quality and energy related issues. The main objective of my research work was to assess the feasibilities of utilization of solar energy for regeneration of desiccant wheel by hot air provided by solar air heater. It will help in saving electrical energy for regeneration of desiccant wheel. In the research work the following assumptions are made: a. The weight of this system is very less and the structure is also porous which allow easy passage for air b. There is very less pressure drop across the wheel of the desiccant system. c. Dew point is low in this system. d. It has the high capacity for removing moisture from air. e. Another advantage of this type of system is its simple ness f. The energy (electricity) required dehumidifying and cool ventilation air is reduced to a great extent g. Improves the efficiency of refrigeration equipment by operating at a higher evaporator temperatures and higher COPh. reduces the spac

Interprofessional knowledge and perceptions of selected South African healthcare practitioners towards each other

Background. Interprofessional collaboration is internationally and popularly envisioned as a successful paradigm for the management of disease, disabilities and injuries. Despite this, the opinion of South African (SA) healthcare practitioners towards this idea is incoherent; this division of opinion needs to be changed to serve the common goal of better patient care.Objective. To provide a narrative overview of literature-based evidence of interprofessional knowledge and perceptions of SA doctors, nurses, physiotherapists, occupational therapists, dieticians, speech and hearing therapists, as well as biokineticists regarding interprofessional collaboration.Methods. An electronic search of Google Scholar, Crossref, PubMed and Sabinet databases identified 701 records, which were synthesised to 11 articles that were published during 2005 - 2016. Individual article quality was appraised using the modified Downs and Black scale.Results. Of the 11 records, 3 were Master’s theses reviewing the interprofessional knowledge and perceptions of doctors, physiotherapists and biokineticists towards the profession of chiropractic therapy; 3 examined the perceptions of chiropractic therapy, occupational therapy, speech and hearing therapy and biokinetics towards physiotherapy and chiropractic therapy; while the remaining 5 were supportive of interprofessional collaboration. The nature of the research designs of the selected studies were: survey (n=6), short communication (n=1), clinical commentary (n=1), randomised controlled trial (n=1) and focus group interview (n=2). An incoherence underlies the perceptions of the abovementioned practitioners regarding interprofessional collaboration owing to lack of interprofessional knowledge regarding each given discipline’s scope of profession (SoP). This is compounded by uneasiness with regard to patient competition. Some physiotherapists are against collaborative relationships, while occupational therapists, biokineticists and chiropractors are inclined to support the notion of a multidisciplinary physical rehabilitation team. There is a paucity of literature-based evidence reviewing the knowledge and perceptions of medical doctors, nurses and physiotherapists with regard to the SoP of occupational therapists, speech and hearing therapists, biokineticists, dieticians and chiropractors, thereby warranting future investigation.Conclusions. There are mixed perceptions of interprofessional collaboration among the selected healthcare practitioners owing to negative perceptions

Numeric taxonomy approaches for lytic evaluation of Salmonella specific bacteriophages

This study explored the lytic ability of bacteriophages as a future tool for reducing the Salmonella spp. loads in food animals. It investigated (a) the concept of a phage cocktail resulting from an exploratory analysis of the 13 phages which were examined, and (b) the possibility of using them in phage typing techniques for a broad range of serotypes. By using the conventional plaque assay method and cluster analysis, it was possible to select the 2/2, N5, 2a, 135KP and 120 phages, as potential elements of a cocktail as a means of efficiently eliminating the greatest number of several types of Salmonella. The 2/2 and N5 phages were also the most efficacious infective elements against the Typhimurium and Enteritidis serovars, respectively.info:eu-repo/semantics/publishedVersio

Value of traditional oral narratives in building climate-change resilience: insights from rural communities in Fiji

In the interests of improving engagement with Pacific Island communities to enable development of effective and sustainable adaptation strategies to climate change, we looked at how traditional oral narratives in rural/peripheral Fiji communities might be used to inform such strategies. Interviews were undertaken and observations made in 27 communities; because the custodians of traditional knowledge were targeted, most interviewees were 70-79 years old. The view that oral traditions, particularly those referring to environmental history and the observations/precursors of environmental change, were endangered was widespread and regretted. Interviewees’ personal experiences of extreme events (natural disasters) were commonplace but no narratives of historical (unwitnessed by interviewees) events were found. In contrast, experiences of previous village relocations attributable (mainly) to environmental change were recorded in five communities while awareness of environmentally driven migration was more common. Questions about climate change elicited views dominated by religious/fatalist beliefs but included some more pragmatic ones; the confusion of climate change with climate variability, which is part of traditional knowledge, was widespread. The erosion of traditional environmental knowledge in the survey communities over recent decades has been severe and is likely to continue apace, which will reduce community self-sufficiency and resilience. Ways of conserving such knowledge and incorporating it into adaptation planning for Pacific Island communities in rural/peripheral locations should be explored

Velocity autocorrelation function of a Brownian particle

In this article, we present molecular dynamics study of the velocity autocorrelation function (VACF) of a Brownian particle. We compare the results of the simulation with the exact analytic predictions for a compressible fluid from [6] and an approximate result combining the predictions from hydrodynamics at short and long times. The physical quantities which determine the decay were determined from separate bulk simulations of the Lennard-Jones fluid at the same thermodynamic state point.We observe that the long-time regime of the VACF compares well the predictions from the macroscopic hydrodynamics, but the intermediate decay is sensitive to the viscoelastic nature of the solvent.Comment: 7 pages, 6 figure

A meta-analysis of protein binding of flucloxacillin in healthy volunteers and hospitalized patients

Objectives: The aim of this study was to develop a mechanistic protein-binding model to predict the unbound flucloxacillin concentrations in different patient populations. Methods: A mechanistic protein-binding model was fitted to the data using non-linear mixed-effects modelling. Data were obtained from four datasets, containing 710 paired total and unbound flucloxacillin concentrations from healthy volunteers, non-critically ill and critically ill patients. A fifth dataset with data from hospitalized patients was used for evaluation of our model. The predictive performance of the mechanistic model was evaluated and compared with the calculation of the unbound concentration with a fixed unbound fraction of 5%. Finally, we performed a fit-for-use evaluation, verifying whether the model-predicted unbound flucloxacillin concentrations would lead to clinically incorrect dose adjustments. Results: The mechanistic protein-binding model predicted the unbound flucloxacillin concentrations more accurately than assuming an unbound fraction of 5%. The mean prediction error varied between -26.2% to 27.8% for the mechanistic model and between -30.8% to 83% for calculation with a fixed factor of 5%. The normalized root mean squared error varied between 36.8% and 69% respectively between 57.1% and 134%. Predicting the unbound concentration with the use of the mechanistic model resulted in 6.1% incorrect dose adjustments versus 19.4% if calculated with a fixed unbound fraction of 5%. Conclusions: Estimating the unbound concentration with a mechanistic protein-binding model outperforms the calculation with the use of a fixed protein binding factor of 5%, but neither demonstrates acceptable performance. When performing dose individualization of flucloxacillin, this should be done based on measured unbound concentrations rather than on estimated unbound concentrations from the measured total concentrations. In the absence of an assay for unbound concentrations, the mechanistic binding model should be preferred over assuming a fixed unbound fraction of 5%

Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

Experimental and numerical investigation of single-beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broad band of amplification appears. Theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent medium response to broadband polychromatic radiation of a multimode dye laser.Comment: 9 pages, 13 figures, corrected, Fig.8 was changed, to be published in Phys. Rev.

Compactifications of Heterotic Theory on Non-Kahler Complex Manifolds: I

We study new compactifications of the SO(32) heterotic string theory on compact complex non-Kahler manifolds. These manifolds have many interesting features like fewer moduli, torsional constraints, vanishing Euler character and vanishing first Chern class, which make the four-dimensional theory phenomenologically attractive. We take a particular compact example studied earlier and determine various geometrical properties of it. In particular we calculate the warp factor and study the sigma model description of strings propagating on these backgrounds. The anomaly cancellation condition and enhanced gauge symmetry are shown to arise naturally in this framework, if one considers the effect of singularities carefully. We then give a detailed mathematical analysis of these manifolds and construct a large class of them. The existence of a holomorphic (3,0) form is important for the construction. We clarify some of the topological properties of these manifolds and evaluate the Betti numbers. We also determine the superpotential and argue that the radial modulus of these manifolds can actually be stabilized.Comment: 75 pages, Harvmac, no figures; v2: Some new results added, typos corrected and references updated. Final version to appear in JHE