The orbital siphon : A new space elevator concept

A new concept for propellantless payload transfer from the surface of the Earth to Earth escape is presented. Firstly, a simple model of a payload ascending or descending a conventional space elevator is developed to explore the underlying dynamics of the problem. It shown that an unconstrained payload at rest on a space elevator at synchronous radius is in an unstable equilibrium, and that this instability can be used to motivate the development of a new concept for payload transfer. It will be shown that a chain of connected payloads stretching from the surface of the Earth to beyond synchronous radius can be assembled which will lift new payloads at the bottom of the chain, while releasing payloads from the top of the chain. The complete system therefore acts as an 'orbital siphon', transporting mass from the surface of the Earth to Earth escape without the need for external work to be done. Indeed the system performs net work by transferring energy from the Earth's rotation to the escaping mass. The dynamics of the siphon effect are explored and key engineering issues are identified

Extraction of bounds on time-reversal non-invariance from neutron reactions

Ratios involving on-resonance measurements of the three-fold and five-fold correlation cross sections for which the dependence on some of the unknown spectroscopic data is eliminated are considered. Closed form expressions are derived for the statistical distributions of these ratios. Implications for bounds on the variance of matrix elements of time reversal non-invariant nucleon-nucleon interactions are considered within a Bayesian framework and the competitiveness with bounds from other experiments is evaluated. The prospects for null five-fold correlation measurements improving by an order of magnitude or more upon the current bound on a parity-conserving T-odd interaction are good.Comment: 14 pages, to be published in Physics Letters

The waiting time paradox: population based retrospective study of treatment delay and survival of women with endometrial cancer in Scotland

No abstract available

Impact of the abolition of EU Milk quotas on Agriculture in the UK

In recent years the CAP has undergone significant reforms, but the dairy sector has largely avoided wholesale changes. The sector, however, is now faced with a significant effort by the Commission to instigate reform. In this study the FAPRI-UK modelling system is simulated to identify the impact of abolishing or phasing out EU milk quotas on the dairy sector in the UK and the results are compared against a 2007 Baseline projection (2007--2016). The results demonstrate that although the impact of the abolition of dairy quotas is fairly modest at the EU-25 level, significant impacts are apparent at the individual country level.Milk Quotas, CAP Reform, Commodity Modelling, Agricultural and Food Policy, International Relations/Trade, Livestock Production/Industries,

A Probabilistic Analysis of Kademlia Networks

Kademlia is currently the most widely used searching algorithm in P2P (peer-to-peer) networks. This work studies an essential question about Kademlia from a mathematical perspective: how long does it take to locate a node in the network? To answer it, we introduce a random graph K and study how many steps are needed to locate a given vertex in K using Kademlia's algorithm, which we call the routing time. Two slightly different versions of K are studied. In the first one, vertices of K are labelled with fixed IDs. In the second one, vertices are assumed to have randomly selected IDs. In both cases, we show that the routing time is about c*log(n), where n is the number of nodes in the network and c is an explicitly described constant.Comment: ISAAC 201

Using an Emergency Plan to Combat Teacher Burnout Following a Natural Hazard

A relevant, well-crafted emergency plan can help schools most optimally return to normal following a disaster. During this time, educators find themselves facing unintended responsibilities like operating on the front lines of providing social-emotional support for their students. Researchers conducted 115 interviews with educators impacted by Hurricanes Harvey and Matthew in Texas and North Carolina to assess their mental health and their school?s role in returning to normal. Findings suggest that emergency plans often did not take into account the social-emotional factors of recovery. This paper seeks to provide insight into the experiences of educators following a disaster and propose elements to consider in revising school emergency plans

The future of pediatric pulmonology: A survey of division directors, assessment of current research funding, and discussion of workforce trends

Adequacy of the US workforce in pediatric pulmonology has been a source of serious concern within the field for some time, as it has been for several pediatric subspecialties. Contributing factors have been thought to include low fill rates of fellowship training programs, aging, and retirement rates of the subspecialist population, and the perception of insufficient numbers of specialists in some regions to meet clinical care needs. Several approaches to assessing workforce needs have already been described, and stakeholder groups are currently working on additional analyses. Although the recent report by Harris et al. captured a broad snapshot of workforce perceptions of 485 pediatric pulmonologists, this study (reporting data collected in 2014) did not address the future scope of practice

Understanding power, social capital and trust alongside near real-time water quality monitoring and technological development collaboration

We report on qualitative social research conducted with stakeholders in a local agricultural knowledge and advice network associated with a collaborative water quality monitoring project. These farmers, advisors and researchers allude to existing social dynamics, technological developments, and (more general) social evolution which is analysed against a novel analytical framework. This framework considers notions of power, social capital, and trust as related and dynamic, forming the basis of our contribution to knowledge. We then probe the data to understand perceived impacts of the collaborative project and social interaction associated with this research project, which involved cutting edge automated and frequent water quality monitoring that allowed for near real-time access to data visualisation displayed via a bespoke mobile or web ‘app’ (1622WQ). Our findings indicate that a multi-faceted approach to assessing and intervening based on consideration of multiple social dimensions holds promise in terms of creating conditions that allow for individual and group learning to encourage changes in thinking required to result in improved land management practice

Momentum transfer using chirped standing wave fields: Bragg scattering

We consider momentum transfer using frequency-chirped standing wave fields. Novel atom-beam splitter and mirror schemes based on Bragg scattering are presented. It is shown that a predetermined number of photon momenta can be transferred to the atoms in a single interaction zone.Comment: 4 pages, 3 figure