N-SAP and G-SAP neutron and gamma ray albedo model scatter shield analysis program

Computer program calculates neutron or gamma ray first order scattering from a plane or cylindrical surface to a detector point. The SAP Codes, G-SAP and N-SAP, constitute a multiple scatter albedo model shield analysis

A dynamics-driven approach to precision machines design for micro-manufacturing and its implementation perspectives

Precision machines are essential elements in fabricating high quality micro products or micro features and directly affect the machining accuracy, repeatability and efficiency. There are a number of literatures on the design of industrial machine elements and a couple of precision machines commercially available. However, few researchers have systematically addressed the design of precision machines from the dynamics point of view. In this paper, the design issues of precision machines are presented with particular emphasis on the dynamics aspects as the major factors affecting the performance of the precision machines and machining processes. This paper begins with a brief review of the design principles of precision machines with emphasis on machining dynamics. Then design processes of precision machines are discussed, and followed by a practical modelling and simulation approaches. Two case studies are provided including the design and analysis of a fast tool servo system and a 5-axis bench-top micro-milling machine respectively. The design and analysis used in the two case studies are formulated based on the design methodology and guidelines

Spring Meadow Management Practices: What’s a Rancher to do?

• Subirrigated meadows are a valuable forage resource to ranching operations in the Nebraska Sandhills, being used for both hay production and livestock grazing. • The water table of these meadows is within one meter of the soil surface during the growing season. • In some years, wet conditions hinder meadow utilization, resulting in a buildup of standing dead and litter plant material which can lower forage production. • Investigate if burning and mowing are effective strategies to remove dead plant material from meadows • Determine if burning or mowing interact with grazing to influence end of season forage production Burning or mowing effectively removes dead plant material from meadows with no later loss in forage production. Burning and mowing do not interact with grazing to influence later forage production. Spring grazing acted independently to significantly lower end of season forage production. Conclusions • Ranchers can use burning or mowing to effectively remove dead plant material from subirrigated meadows in the Nebraska Sandhills with no later losses in forage production (Fig.1 & Fig.2). • On the other hand, spring grazing reduces end of season forage production (Fig.3). Therefore, caution should be used with spring grazing if a rancher’s goal is to maximize hay yields from meadow forage

Quantum walks in higher dimensions

We analyze the quantum walk in higher spatial dimensions and compare classical and quantum spreading as a function of time. Tensor products of Hadamard transformations and the discrete Fourier transform arise as natural extensions of the quantum coin toss in the one-dimensional walk simulation, and other illustrative transformations are also investigated. We find that entanglement between the dimensions serves to reduce the rate of spread of the quantum walk. The classical limit is obtained by introducing a random phase variable.Comment: 6 pages, 6 figures, published versio

O(a)O(a) Improvement for Quenched Wilson Fermions

We briefly describe some of our recent results for the mass spectrum and matrix elements using $O(a)$ improved fermions for quenched QCD. Where possible a comparison is made between improved and Wilson fermions.Comment: 6 pages, Latex, 11 figures, epsf.sty and buckow1.sty needed (buckow1.sty included). Talk presented at the 31st Ahrenshoop Symposium on the Theory of Elementary Particles, September 1997, Buckow, German

General practitioners' knowledge, attitudes and views of providing preconception care: a qualitative investigation

Background: Preconception health and care aims to reduce parental risk factors before pregnancy through health promotion and intervention. Little is known about the preconception interventions that general practitioners (GPs) provide. The aim of this study was to examine GPs’ knowledge, attitudes, and views towards preconception health and care in the general practice setting. Methods: As part of a large mixed-methods study to explore preconception care in England, we surveyed 1,173 women attending maternity units and GP services in London and interviewed women and health professionals. Seven GPs were interviewed, and the framework analysis method was used to analyse the data. Findings: Seven themes emerged from the data: Knowledge of preconception guidelines; Content of preconception advice; Who should deliver preconception care?; Targeting provision of preconception care; Preconception health for men; Barriers to providing preconception care; and Ways of improving preconception care. A lack of knowledge and demand for preconception care was found, and although reaching women before they are pregnant was seen as important it was not a responsibility that could be adequately met by GPs. Specialist preconception services were not provided within GP surgeries, and care was mainly targeted at women with medical conditions. GPs described diverse patient groups with very different health needs. Conclusion: Implementation of preconception policy and guidelines is required to engage women and men and to develop proactive delivery of care with the potential to improve pregnancy and neonatal outcomes. The role of education and of nurses in improving preconception health was acknowledged but remains under-developed

High-rate, high-fidelity entanglement of qubits across an elementary quantum network

We demonstrate remote entanglement of trapped-ion qubits via a quantum-optical fiber link with fidelity and rate approaching those of local operations. Two ${}^{88}$Sr${}^{+}$ qubits are entangled via the polarization degree of freedom of two photons which are coupled by high-numerical-aperture lenses into single-mode optical fibers and interfere on a beamsplitter. A novel geometry allows high-efficiency photon collection while maintaining unit fidelity for ion-photon entanglement. We generate remote Bell pairs with fidelity $F=0.940(5)$ at an average rate $182\,\mathrm{s}^{-1}$ (success probability $2.18\times10^{-4}$).Comment: v2 updated to include responses to reviewers, as published in PR