A comparison of two position estimate algorithms that use ILS localizer and DME information. Simulation and flight test results

Simulation and flight tests were conducted to compare the accuracy of two algorithms designed to compute a position estimate with an airborne navigation computer. Both algorithms used ILS localizer and DME radio signals to compute a position difference vector to be used as an input to the navigation computer position estimate filter. The results of these tests show that the position estimate accuracy and response to artificially induced errors are improved when the position estimate is computed by an algorithm that geometrically combines DME and ILS localizer information to form a single component of error rather than by an algorithm that produces two independent components of error, one from a DMD input and the other from the ILS localizer input

pdFOAM: A PIC-DSMC code for near-earth plasma-body interactions

Understanding the interaction of the near-Earth space environment with orbiting bodies is critical, both from a design and scientific perspective. In Low Earth Orbit (LEO), the interaction between the Ionosphere and orbiting objects is well studied from a charging perspective. Not well understood is the effect of the Ionosphere on the motion of LEO objects i.e. charged aerodynamics. This paper presents the implementation, validation, and verification of the hybrid electrostatic Particle-in-Cell (PIC) - Direct Simulation Monte Carlo (DSMC) code, pdFOAM, to study both the neutral and charged particle aerodynamics of LEO objects. The 2D aerodynamic interaction of a cylinder with a fixed uniform surface potential of −50 V in mesothermal O+ and H+ plasmas representative of ionospheric conditions is investigated. New insights into the role of bounded ion jets and their effect on surface forces are presented. O+ bounded ion jets are observed to cause a 4.4% increase in direct Charged Particle Drag (dCPD), while H+ ion jets produce a net reduction in H+ dCPD by 23.7% i.e. they cause a thrust force. As a result, this paper concludes the study of charged aerodynamics in LEO requires a self-consistent modelling tool, such as pdFOAM

Immorality and Irrationality

Does immorality necessarily involve irrationality? The question is often taken to be among the deepest in moral philosophy. But apparently deep questions sometimes admit of deflationary answers. In this case we can make way for a deflationary answer by appealing to dualism about rationality, according to which there are two fundamentally distinct notions of rationality: structural rationality and substantive rationality. I have defended dualism elsewhere. Here, I’ll argue that it allows us to embrace a sensible – I will not say boring – moderate view about the relationship between immorality and irrationality: roughly, that immorality involves substantive irrationality, but not structural irrationality. I defend this moderate view, and argue that many of the arguments for less moderate views turn either on missing the distinction between substantive and structural rationality, or on misconstruing it

Factors influencing the utilisation of free-standing and alongside midwifery units in England: a qualitative research study

OBJECTIVE: To identify factors influencing the provision, utilisation and sustainability of midwifery units (MUs) in England. DESIGN: Case studies, using individual interviews and focus groups, in six National Health Service (NHS) Trust maternity services in England. SETTING AND PARTICIPANTS: NHS maternity services in different geographical areas of England Maternity care staff and service users from six NHS Trusts: two Trusts where more than 20% of all women gave birth in MUs, two Trusts where less than 10% of all women gave birth in MUs and two Trusts without MUs. Obstetric, midwifery and neonatal clinical leaders, managers, service user representatives and commissioners were individually interviewed (n=57). Twenty-six focus groups were undertaken with midwives (n=60) and service users (n=52). MAIN OUTCOME MEASURES: Factors influencing MU use. FINDINGS: The study findings identify several barriers to the uptake of MUs. Within a context of a history of obstetric-led provision and lack of decision-maker awareness of the clinical and economic evidence, most Trust managers and clinicians do not regard their MU provision as being as important as their obstetric unit (OU) provision. Therefore, it does not get embedded as an equal and parallel component in the Trust's overall maternity package of care. The analysis illuminates how implementation of complex interventions in health services is influenced by a range of factors including the medicalisation of childbirth, perceived financial constraints, adequate leadership and institutional norms protecting the status quo. CONCLUSIONS: There are significant obstacles to MUs reaching their full potential, especially free-standing midwifery units. These include the lack of commitment by providers to embed MUs as an essential service provision alongside their OUs, an absence of leadership to drive through these changes and the capacity and willingness of providers to address women's information needs. If these remain unaddressed, childbearing women's access to MUs will continue to be restricted

First-principles insights into tin-based two-dimensional hybrid halide perovskites for photovoltaics

The two-dimensional (2D) hybrid halide perovskites have recently attracted attention due to their excellent photovoltaic performance. In comparison to their three-dimensional (3D) analogues, they show superior long-term durability and moisture tolerance. Meanwhile, their layered topology offers greater flexibility for electronic structure tuning. To date, most devices containing 2D perovskites have been based on Pb, which presents environment concerns and a possible roadblock to commercialisation due to its toxicity. The development of lead-free alternatives is therefore immensely important to facilitate the uptake of perovskite-based photovoltaics. Herein, we investigate the geometrical, electronic and optical properties of the semiconducting 2D tin perovskites (CH 3 (CH 2 ) 3 NH 3 ) 2 (CH 3 NH 3 ) n-1 Sn n I 3n+1 (n = 1, 2 and 3), using relativistic hybrid density functional theory calculations. We demonstrate that the band gaps of the series decrease with increasing perovskite-like layer thickness, from 1.85 eV (n = 1) to 1.38 eV (n = 3). We find strong and broad optical absorption across the series, in addition to small effective masses of electrons and holes in the laminar plane. The n = 3 composition displays a high spectroscopic limited maximum efficiency of 24.6%. Our results indicate this series of homologous 2D tin halide perovskites are a promising class of stable and efficient light-absorbing materials for photovoltaics

The Strength of a Smile: Duchenne Smiles Improve Advertisement and Product Evaluations

Consumer research recognizes the well-established effect of positive emotions on consumers, i.e. consumers in positive moods tend to give positive evaluations of products and advertisements. Recently, researchers have investigated the use of Duchenne smiles (genuine smiles) in advertisements to evoke positive emotions and lead to positive evaluations. Duchenne smiles are identified by the activation of both the zygomaticus major muscle (which pulls up the corners of the mouth) and the orbicularis oculi muscles (which surround the eye and result in the crow’s feet wrinkles). Peace, Miles, and Johnston (2006) demonstrated that including Duchenne smiles in mock print advertisements affects viewers’ perceptions of the ad and featured product, resulting in more positive evaluations as compared to neutral and non-Duchenne advertisements. The current research expands on Peace et al. and examines the effects of type of smile displayed in mock print advertisements that feature inexpensive and expensive products alike. Participants rated pairs of advertisements created by the researchers. Participants significantly preferred Duchenne smiling advertisements over non Duchenne and also showed significant preference in their likelihood to purchase products in Duchenne advertisements. A potential mimicry association mechanism is discussed, as well as practical implications for advertisers

Asymmetries in the Value of Existence

According to asymmetric comparativism, it is worse for a person to exist with a miserable life than not to exist, but it is not better for a person to exist with a happy life than not to exist. My aim in this paper is to explain how asymmetric comparativism could possibly be true. My account of asymmetric comparativism begins with a different asymmetry, regarding the (dis)value of early death. I offer an account of this early death asymmetry, appealing to the idea of conditional goods, and generalize it to explain how asymmetric comparativism could possibly be true. I also address the objection that asymmetric comparativism has unacceptably antinatalist implications

Beam alignment techniques based on the current multiplication effect in photoconductors Third summary technical progress report, 15 Nov. 1966 - 15 Oct. 1967

Beam alignment techniques developed for infrared sensitive single crystal germanium to study multiplication effect in photoconductor

Factors influencing utilisation of ‘free-standing’ and ‘alongside’ midwifery units for low-risk births in England: a mixed-methods study

Background Midwifery-led units (MUs) are recommended for ‘low-risk’ births by the National Institute for Health and Care Excellence but according to the National Audit Office were not available in one-quarter of trusts in England in 2013 and, when available, were used by only a minority of the low-risk women for whom they should be suitable. This study explores why. Objectives To map the provision of MUs in England and explore barriers to and facilitators of their development and use; and to ascertain stakeholder views of interventions to address these barriers and facilitators. Design Mixed methods – first, MU access and utilisation across England was mapped; second, local media coverage of the closure of free-standing midwifery units (FMUs) were analysed; third, case studies were undertaken in six sites to explore the barriers and facilitators that have an impact on the development of MUs; and, fourth, by convening a stakeholder workshop, interventions to address the barriers and facilitators were discussed. Setting English NHS maternity services. Participants All trusts with maternity services. Interventions Establishing MUs. Main outcome measures Numbers and types of MUs and utilisation of MUs. Results Births in MUs across England have nearly tripled since 2011, to 15% of all births. However, this increase has occurred almost exclusively in alongside units, numbers of which have doubled. Births in FMUs have stayed the same and these units are more susceptible to closure. One-quarter of trusts in England have no MUs; in those that do, nearly all MUs are underutilised. The study findings indicate that most trust managers, senior midwifery managers and obstetricians do not regard their MU provision as being as important as their obstetric-led unit provision and therefore it does not get embedded as an equal and parallel component in the trust’s overall maternity package of care. The analysis illuminates how provision and utilisation are influenced by a complex range of factors, including the medicalisation of childbirth, financial constraints and institutional norms protecting the status quo. Limitations When undertaking the case studies, we were unable to achieve representativeness across social class in the women’s focus groups and struggled to recruit finance directors for individual interviews. This may affect the transferability of our findings. Conclusions Although there has been an increase in the numbers and utilisation of MUs since 2011, significant obstacles remain to MUs reaching their full potential, especially FMUs. This includes the capacity and willingness of providers to address women’s information needs. If these remain unaddressed at commissioner and provider level, childbearing women’s access to MUs will continue to be restricted. Future work Work is needed on optimum approaches to improve decision-makers’ understanding and use of clinical and economic evidence in service design. Increasing women’s access to information about MUs requires further studies of professionals’ understanding and communication of evidence. The role of FMUs in the context of rural populations needs further evaluation to take into account user and community impact. Funding This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 12. See the NIHR Journals Library website for further project information