Extreme vacuum technology including cryosorption, diffusion pump and pressure calibration studies Summary technical report, 1 Feb. 1965 - 1 Mar. 1966

Cryosorption, diffusion pump, and pressure calibration studies in extreme vacuum science and technology application progra

Extreme vacuum technology including cryosorption, diffusion pump and pressure calibration studies Quarterly status report no. 8, 1 May - 1 Aug. 1965

Cryosorption, diffusion pump, and low pressure calibration studies on Penning gauge and cold cathode magnetro

Study of low pressure application of the orbitron

Evaluation of low pressure performance of orbitron ionization gaug

Constructing compact 8-manifolds with holonomy Spin(7) from Calabi-Yau orbifolds

Compact Riemannian 7- and 8-manifolds with holonomy G(2) arid Spin(7) were first constructed by the author in 1994-5, by resolving orbifolds T-7/Gamma and T-8/Gamma. This paper describes a new construction of compact 8-manifolds with holonomy Spin(7). We start with a Calabi-Yau 4-orbifold Y with isolated singularities of a special kind. We divide by an antiholomorphic involution a of Y to get a real 8-orbifold Z = Y/. Then we resolve tire singularities of Z to get a compact 8-manifold M, which has metrics with holonomy Spin(7). Manifolds constructed in this way typically have large fourth Betti number b(4)(M).</sigma

Extreme vacuum technology developments

Ultrahigh vacuum environments technology development

Closed trajectories of a particle model on null curves in anti-de Sitter 3-space

We study the existence of closed trajectories of a particle model on null curves in anti-de Sitter 3-space defined by a functional which is linear in the curvature of the particle path. Explicit expressions for the trajectories are found and the existence of infinitely many closed trajectories is proved.Comment: 12 pages, 1 figur

A settlers' guide: Designing for resilience in the hinterlands

© 2017 by the authors. There has often been a mutually beneficial relationship between cities and their rural hinterlands. The Kapiti region outside the city of Wellington in New Zealand is a prime example: it once provided Wellington's food, water and cultural diversity for both Māori and European settlers. However, productivity-driven agriculture and extensive dormitory-suburbanization have affected significant parts of this once-abundant hinterland. Food production is becoming more mono-cultural, water quality is degrading, ecosystems' biodiversity is disappearing, provincial town centres are shrinking, emigrating youth are leaving unbalanced demographics, Māori are increasingly disassociating their culture from their traditional lands and natural disasters are causing more impact-all of which is making Kapiti less resilient, and severing the once-healthy city-hinterland relationship. Our work on future settlement opportunities in Kapiti proposes alternatives, using experimental design-led research methods to develop speculative architectural and landscape architectural schemes. The schemes are framed by some of the spatial attributes of resilience: diversity, complexity, redundancy, interconnectivity and adaptability. Collectively, the work reveals design strategies that have a potential to rebuild hinterlands' culture, town centres, housing, agriculture, community and ecosystems and to recalibrate the broader relationship between hinterlands and metropolitan systems

A New Concept for the Control of a Slow-Extracted Beam in a Line with Rotational Optics, 2

The current trend in hadrontherapy is towards high-precision, conformal scanning of tumours with a 'pencil' beam of light ions, or protons, delivered by a synchrotron using slow-extraction. The particular shape of the slow-extracted beam segment in phase space and the need to vary the beam size in a lattice with rotating optical elements create a special problem for the design of the extraction transfer line and gantry. The design concept presented in this report is based on telescope modules with integer-p phase advances in both transverse planes. The beam size in the plane of the extraction is controlled by altering the phase advance and hence the rotation of the extracted beam segment in phase space. The vertical beam size is controlled by stepping the vertical betatron amplitude function over a range of values and passing the changed beam size from 'hand-to-hand' through the telescope modules to the various treatment rooms. In the example given, a combined phase-shifter and 'stepper', at a point close to the synchrotron, controls both of these functions for all treatment rooms in the complex. The modular nature of the design makes it easy to extend the complex

Towards Verifying Nonlinear Integer Arithmetic

We eliminate a key roadblock to efficient verification of nonlinear integer arithmetic using CDCL SAT solvers, by showing how to construct short resolution proofs for many properties of the most widely used multiplier circuits. Such short proofs were conjectured not to exist. More precisely, we give n^{O(1)} size regular resolution proofs for arbitrary degree 2 identities on array, diagonal, and Booth multipliers and quasipolynomial- n^{O(\log n)} size proofs for these identities on Wallace tree multipliers.Comment: Expanded and simplified with improved result

Beyond Search: A Technology Probe Investigation

Purpose — We assert that researchers developing new web interaction tools should consider an array of user motives beyond query-based information retrieval. This chapter reports on two probes used to investigate user activities that go beyond search as traditionally conceived. Design/methodology — This chapter reviews research on user experiences with search engines and general web use. It then describes the design and case study of cards and pebbles, two search engine-based probes developed to help elicit new concepts for web-based experiences. Findings — Participants reflect on their experiences with the probes and offer ideas regarding how to incrementally shift the traditional search paradigm and conceive of the web in new ways. Implications/value — This investigation serves as a starting point by offering criteria that should be considered when designing new ‘beyond search’ tools