Photon emission induced by elastic exciton--carrier scattering in semiconductor quantum wells

We present a study of the elastic exciton--electron ($X-e^-$) and exciton--hole ($X-h$) scattering processes in semiconductor quantum wells, including fermion exchange effects. The balance between the exciton and the free carrier populations within the electron-hole plasma is discussed in terms of ionization degree in the nondegenerate regime. Assuming a two-dimensional Coulomb potential statically screened by the free carrier gas, we apply the variable phase method to obtain the excitonic wavefunctions, which we use to calculate the 1$s$ exciton--free carrier matrix elements that describe the scattering of excitons into the light cone where they can radiatively recombine. The photon emission rates due to the carrier-assisted exciton recombination in semiconductor quantum-wells (QWs) at room temperature and in a low density regime are obtained from Fermi's golden rule, and studied for mid-gap and wide-gap materials. The quantitative comparison of the direct and exchange terms of the scattering matrix elements shows that fermion exchange is the dominant mechanism of the exciton--carrier scattering process. This is confirmed by our analysis of the rates of photon emission induced by electron-assisted and hole-assisted exciton recombinations.Comment: Thoroughly revised version of previous work. Weak and incorrect assumptions have been removed from the paper, and its scope has evolved: see abstract. This is the final version, i.e. as accepted for publication in the European Physical Journal

Advanced Practice and Specialisation in Pharmacy: Global Report 2015

This report is the most comprehensive collection of data and evidence that relates to practitioner advancement of practice and policy, and maps out a wide range of national initiatives worldwide. This report should be viewed as a first attempt to map out global trends and will stimulate further reportage and analysis as engagement in this practice continues to progress

Variable-phase method and Levinson's theorem in two dimensions: Application to a screened Coulomb potential

Copyright © 1997 Elsevier. NOTICE: this is the pre-print version of a work that was accepted for publication in Solid State Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Solid State Communications Volume 103, Issue 6, pp. 325–329 (1997). DOI: 10.1016/S0038-1098(97)00203-2The variable-phase approach is applied to scattering and bound states in an attractive Coulomb potential, statically screened by a two-dimensional (2D) electron gas. A 2D formulation of Levinson's theorem is used for bound-state counting and a hitherto undiscovered, simple relationship between the screening length and the number of bound states is found. As the screening length is increased, sets of bound states with differing quantum numbers appear degenerately. (C) 1997 Elsevier Science Ltd

A global survey on trends in advanced practice and specialisation in the pharmacy workforce

OBJECTIVES: Despite the increasingly complex care and demanding health challenges shaping pharmacy, little work has been carried out to understand the global status of advanced and/or specialised pharmacy practice scopes and the models in which they exist. This study aims to describe the current global status of initiatives relating to advancement of pharmacy practice. METHODS: A global survey was conducted between January and May 2015 to collect country‐level data from member organisations of the International Pharmaceutical Federation (FIP), and national‐level contacts from regulatory, professional and government agencies or universities; data requests were sent to 109 countries. The collected data were triangulated (comparing multiple sources from single countries, e.g.), cleaned and analysed by descriptive and comparative statistics. KEY FINDINGS: Full data sets from 48 countries and territories were obtained. The findings demonstrate varying systems of advanced pharmacy practice and specialisation often linked to income level. The study found that there are variations within terminology and definitions, frameworks for specialisation and advanced practice, professional recognition mechanisms and benefits across countries. CONCLUSIONS: This survey of 48 countries and territories was the first of its kind to describe the range of specialisation and professional recognition systems for advanced pharmacy practice worldwide. Despite the variance, it is clear from this global study that professional advancement and the recognition of advancement in practice are developing around the world and this could be due to the increasingly complex nature of pharmaceutical care delivery and a consequent need to be able to endorse professional capabilities

Trends in advanced practice and specialisation in the global pharmacy workforce: a synthesis of country case studies

OBJECTIVES: This study aims to gain a better understanding of the drivers and barriers to the development of advanced practice and specialised systems around the world. Through the synthesis of in‐depth country case studies, this paper aims to identify current models of advanced practice and specialisation in pharmacy and illustrate trends, drivers and barriers in policy development. This is the first analysis of its kind to examine pharmacy specialisation and advanced practice in this depth from a global perspective. METHODS: A synthesis of country case studies was carried out. The country case study template was reviewed and approved by an expert working group drawn from a cross section of International Pharmaceutical Federations (FIP) experts and special‐interest groups. FIP member organisations and country‐level contacts from regulatory, professional and government agencies and universities were approached to contribute to the case study database. The data were collected between January and May 2015. Descriptive comparative analysis and qualitative thematic analysis were both used to analyse the data. KEY FINDINGS: Case study submissions were received from 17 countries. The findings demonstrate that the pace and depth of change in advanced practice and specialisation are occurring at different rates across countries and regions, although many countries appear to be moving towards recognising advanced and specialised practice of pharmacists and developing frameworks and/or formalised recognition systems. CONCLUSIONS: Country‐specific examples are useful in identifying factors that may contribute to the rate at which developments in advanced practice and specialisation in pharmacy are taking place and enable progress in around the world

An Experimental and Numerical Study to Validate an Aerodynamic Model of Yawed Flow Over a Wind Turbine. Internal Report Number 9825

No abstract available

An Experimental and Numerical Study to Validate an Aerodynamic Model of Yawed Flow Over a Wind Turbine. Internal Report Number 9825

No abstract available

An Analysis of Dialogue Repair in Virtual Voice Assistants

Language speakers often use what are known as repair initiators to mend fundamental disconnects that occur between them during verbal communication. Previous research in this field has mainly focused on the human-to-human use of repair initiator. We proposed an examination of dialogue repair structure wherein the dialogue initiator is human and the party that initiates or responds to the repair is a virtual assistant. This study examined the use of repair initiators in both English and Spanish with two popular assistants, Google Assistant and Apple's Siri. Our aim was to codify the differences, if any, in responses by voice assistants to dialogues in need of repair as compared to human-human dialogues also in need of repair. Ultimately the data demonstrated that not only were there differences between human-assistant and human-human dialogue repair strategies, but that there were likewise differences among the assistants and the languages studied.Comment: 2021, non-print, unpublished versio

An assessment of pile driveability analyses for monopile foundations

Several methodologies to predict the static soil resistance to driving (SRD) available in the literature have found wide use in the offshore industry over the last decades. These range from simple methods that require few soil strength parameters to more advanced semi-empirical methods that correlate the driving resistance to cone penetration test measurements. These methods were primarily developed based on driving records for piles less than 2.5m in diameter i.e. much smaller than the monopiles currently used in the offshore wind industry today. The aim of this study is to evaluate the accuracy of some of the most widely used SRD prediction methods when employed for driveability analysis of large diameter monopile foundations, by comparing the predicted SRD profiles with the driving records of 6.5m diameter monopiles installed in the Danish region of the North Sea