Characterization of gasoline/ethanol blends by infrared and excess infrared spectroscopy

This work was supported by the Northern Research Partnership (NRP) in Scotland and the Scottish Sensor Systems Centre (SSSC) funded by the Scottish Funding Council (SFC).Peer reviewedPostprin

A new language is born

Peer Reviewe

Modelling of optical traps for aerosols

Experimental observations suggest that there are differences between the behavior of particles optically trapped in air and trapped in a liquid phase. We present a modified version of Mie Debye Spherical Aberration theory to numerically simulate such optical system in attempt to explain and predict these effects. The model incorporates Mie scattering and focussing of the trapping beam through media of stratified refractive index. Our results show a geometrical optics approach cannot correctly describe our system and that spherical aberration must be included. We successfully qualitatively explain the observed phenomena and those of other authors, before discussing the limits of our experimental techniques and methods to improve it. We draw the important conclusion that when optically trapping aerosols the system does not behave as a true `optical tweezers', varying between levitation and single beam gradient force trapping depending on particle and beam parameters

An exploration of patients’ reconstructive memories of critical care and nurses’ understanding and response to these: a qualitative study

Background As greater numbers of individuals survive critical care, critical care nurses require an understanding of patients’ memories of this experience. This is important because the critical care that nurses deliver may contribute to patients’ memories of this episode in their life which irrespective of their objective accuracy and may have implications for patients’ emotional well-being and longer-term critical care survivorship. This involves moving on with life, with individuals’ often needing to redefine themselves as a result of the legacies of a critical care stay and regaining control of their life. Aims of the research Through the theoretical lens of Bartlett’s (1932) theory of reconstructive memory, this research aimed to explore patients’ reconstructive memories of critical care and to develop an understanding of how nursing practice may contribute to these and patients’ longer term critical care survivorship. Through identifying similarities and differences between patients’ reconstructive memories of critical care and nurses’ understandings of these, this research also aimed to make recommendations for nursing practice, research and education. Research design and methods Drawing upon the work of Creswell and Plano Clark (2011) this qualitative research adopted an exploratory sequential design entailing one study with separate phases. Phase one involved interviews with former critical care patients (n=15) to collect qualitative data that were analysed through the constant comparative analysis method. A second phase involving focus groups collected and analysed further qualitative data from nurses (n=33) who all practised on critical care units (CCUs). A final phase explored convergence and divergence between patients’ reconstructive memories of receiving critical care and the understanding of these demonstrated by critical care nurses. Findings Critical care patients reported missing memories of critical care. They demonstrated a need to address these and make sense of their situation and experiences. They felt only then could they achieve closure on this episode of their life and move on with their survivorship and the second chance of life that critical care had provided. To try to address these gaps in memories, patients developed rich reconstructive memories of critical care. To do this, they placed extreme value on family members experiences, understanding and support along with those provided through critical care follow-up services. In contrast, the critical care nurses demonstrated a limited understanding of patients’ memories of critical care, confining their considerations to the CCU stay. There was a lack of awareness of the value patients place on family members to support their memories and critical care survivorship. Instead, nurses drew heavily upon the medical model to explain patients’ memories of critical care. Conclusion Nurses working within CCUs demonstrated an overreliance on the medical model which focuses on organ dysfunction and disease, to understand patients’ memories of critical care. In contrast, patients’ focus was more on their personal experience of receiving care on the CCU and then their recovery and ability to achieve closure on this episode and to move on with their life. Central to this for patients, was the role their family members played to help them address their missing memories of critical care and make sense of and understand their experience. Thus it is recommended that critical care nursing practice moves towards a holistic, patient family-centred approach to care which supports the development of patients’ reconstructive memories. This may contribute to patients’ ability to achieve closure on this period of their life and move on with their critical care survivorship

Acoustic black holes in a two-dimensional "photon-fluid"

Optical field fluctuations in self-defocusing media can be described in terms of sound waves in a 2D photon-fluid. It is shown that, while the background fluid couples with the usual flat metric, sound-like waves experience an effective curved spacetime determined by the physical properties of the flow. In an optical cavity configuration, the background spacetime can be suitably controlled by the driving beam allowing the formation of acoustic ergoregions and event horizons. An experiment simulating the main features of the rotating black hole geometry is proposed.Comment: revised versio