Close space sublimation of CdTe for solar cells and the effect of underlying layers

This work has focused on the design, construction and testing of a close space sublimation system for CdTe deposition. In addition, it also focused on variations to the treatment and fabrication procedures of the transparent conducting oxide and CdS layers prior to the CdTe deposition, in order to influence the structure and electrical properties of the CdTe/CdS interface. CdTe was deposited by the physical vapour process, close space sublimation. The equipment used was custom built for this work and is therefore described in detail. Some of the deposition parameters of the equipment were varied in order to allow a comparison between the equipment in this work and those reported in the literature. Bilayers of CdS have been created by depositing two individual CdS layers, on top of one another, whilst also varying the annealing treatment of the first layer. These bilayers were included in devices and which subsequently underwent a series of etches to allow analysis of the materials. The bilayers were shown to effect the preferred orientation of the CdTe layer deposited on top, but the results suggested the bilayers had a negative effect on the amount of current recombination in the depletion region. The roughness of the transparent conducting oxide coated glass substrates used in this work, was proposed as a way of influencing the roughness of the CdS layer deposited on top and therefore the roughness of the layer the CdTe is deposited on. It was proposed that the CdTe material deposited on a roughened substrate may have an increased grain size; no evidence for this was found for samples including CdS layers. A second phase of CdTe was observed and assigned to the presence of a CdSxTe1−x alloy. The sulphur content of the alloy was found to increase as the roughness of the substrate increased. CdS was deposited by the wet chemistry process chemical bath deposition. In situ monitoring of the deposition was carried out by studying the re ection of light from the interface at the end of an optical fibre placed within the solution. The results indicated that the in situ monitoring was sensitive to the initial deposition but the sensitivity reduced as the film thickness approached 150 nm. The in situ monitoring technique and ellipsometry measurements of the CdS showed good agreement with the theory of two deposition mechanisms occurring during the deposition. The results showed that CdS grown by chemical bath deposition has a two layer structure consistent with; a low density CdS grown by homogeneous deposition, on top of dense CdS grown by ion by ion deposition. An ellipsometry model for the CdS and CdTe layers is presented, along with its optical properties over the wavelength range 245 to 1690 nm.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Interlending and resource-sharing in UK public libraries: a mixed methods study

This paper presents the results of a mixed methods study of interlending and resource sharing in UK public libraries, based on the results of a survey distributed to both senior library managers and interlending staff, and in-depth follow-up interviews with twenty respondents. We present an analysis of perspectives towards rates of interlending, the rationales and strategies for providing the service, the perceived value for money offered by various interlending schemes, the impact of the current digital environment, and views on the future of interlending in the UK. Our findings suggest that while interlending services are undoubtedly threatened by the drastic cuts to public library funding, and that demand for the service is more generally in decline, resource sharing is viewed by some as a potential means of mitigating the effects of increasingly limited acquisitions budgets, and ensuring the public library system continues to provide access to a wide range of resources for its users

Effect of intraoperative fluid optimisation on renal function in patients undergoing emergency abdominal surgery; a randomised controlled pilot study (ISRCTN 11799696) Fluid optimisation for emergency surgery

<b>Background:</b> Emergency abdominal surgery carries a high risk of postoperative morbidity and mortality. Goal directed therapy has been advocated to improve outcome in high-risk surgery. The aim of the present pilot study was to examine the effect of goal directed therapy using fluid alone on postoperative renal function and organ failure score in patients undergoing emergency abdominal surgery. <b>Methods:</b> This prospective randomised pilot study included patients over the age of 50 undergoing emergency abdominal surgery. In the intervention group pulse pressure variation measurements were used to guide fluid boluses of 6% Hydroxyethylstarch 130/0.4. The control group received standard care. Serum urea, creatinine and cystatin C levels were measured prior to and at the end of surgery and postoperatively on day 1, day 3 and day 5. <b>Results:</b> Thirty patients were recruited. One patient died prior to surgery and was excluded from the analysis. The intervention group received a median of 750ml of hydroxyethylstarch. The peak values of postoperative urea were 6.9 (2.7–31.8) vs. 6.4 (3.5–11.5)mmol/l (p=0.425), creatinine 100 (60–300) vs. 85 (65–150) μmol/l (p=0.085) and cystatin C 1.09 (0.66–4.94) vs. 1.01 (0.33–2.29)mg/dl (p=0.352) in the control and intervention group, respectively. <b>Conclusions:</b> In the present pilot study replacing the identified fluid deficit was not associated with a change in renal function. These results do not preclude that goal directed therapy using fluid alone may have an effect on renal function but they would suggest that the effect size of fluid optimisation alone on renal function is small

The effect of discrete vs. continuous-valued ratings on reputation and ranking systems

When users rate objects, a sophisticated algorithm that takes into account ability or reputation may produce a fairer or more accurate aggregation of ratings than the straightforward arithmetic average. Recently a number of authors have proposed different co-determination algorithms where estimates of user and object reputation are refined iteratively together, permitting accurate measures of both to be derived directly from the rating data. However, simulations demonstrating these methods' efficacy assumed a continuum of rating values, consistent with typical physical modelling practice, whereas in most actual rating systems only a limited range of discrete values (such as a 5-star system) is employed. We perform a comparative test of several co-determination algorithms with different scales of discrete ratings and show that this seemingly minor modification in fact has a significant impact on algorithms' performance. Paradoxically, where rating resolution is low, increased noise in users' ratings may even improve the overall performance of the system.Comment: 6 pages, 2 figure

UK informative inventory report (1990 to 2013)

This is the 10th Informative Inventory Report (IIR) from the UK National Atmospheric Emissions Inventory (NAEI) Programme. The report is compiled to accompany the UK’s 2015 data submission under the United Nations Economic Commission for Europe (UNECE) Convention on Long-Range Transboundary Air Pollution (CLRTAP) and contains detailed information on annual emission estimates of air quality pollutants by source in the UK from 1990 onwards

Fulvestrant: an oestrogen receptor antagonist with a novel mechanism of action

Due to their favourable tolerability profiles, endocrine therapies have long been considered the treatment of choice for hormone-sensitive metastatic breast cancer. However, the oestrogen agonist effects of the available selective oestrogen receptor modulators, such as tamoxifen, and the development of cross-resistance between endocrine therapies with similar modes of action have led to the need for new treatments that act through different mechanisms. Fulvestrant (‘Faslodex’) is the first of a new type of endocrine treatment – an oestrogen receptor (ER) antagonist that downregulates the ER and has no agonist effects. This article provides an overview of the current understanding of ER signalling and illustrates the unique mode of action of fulvestrant. Preclinical and clinical study data are presented in support of the novel mechanism of action of this new type of ER antagonist

Scallop swimming kinematics and muscle performance: modelling the effects of "within-animal" variation in temperature sensitivity

Escape behaviour was investigated in Queen scallops (Aequipecten opercularis) acclimated to 5, 10 or 15 degrees C and tested at their acclimation temperature. Scallops are active molluscs, able to escape from predators by jet-propelled swimming using a striated muscle working in opposition to an elastic hinge ligament. The first cycle of the escape response was recorded using high-speed video ( 250 Hz) and whole-animal velocity and acceleration determined. Muscle shortening velocity, force and power output were calculated using measurements of valve movement and jet area, and a simple biomechanical model. The average shortening speed of the adductor muscle had a Q(10) of 2.04, significantly reducing the duration of the jetting phase of the cycle with increased temperature. Muscle lengthening velocity and the overall duration of the clap cycle were changed little over the range 5 - 15 degrees C, as these parameters were controlled by the relatively temperature-insensitive, hinge ligament. Improvements in the average power output of the adductor muscle over the first clap cycle ( 222 vs. 139 W kg(-1) wet mass at 15 and 5 degrees C respectively) were not translated into proportional increases in overall swimming velocity, which was only 32% higher at 15 degrees C ( 0.37m s(-1)) than 5 degrees C (0.28 m s(-1))

Interventions for the well-being of healthcare workers during a pandemic or other crisis : scoping review

Funding This study was supported by Chief Scientist Office of Scotland, grant number COV/ABN/20/06. Acknowledgements The authors thank Vicki Cormie, librarian at University of St Andrews, for advice on conducting scoping reviews.Peer reviewedPublisher PD