612 research outputs found
The FNAL injector upgrade
The present FNAL H- injector has been operational since the 1970s and
consists of two magnetron H- sources and two 750 keV Cockcroft-Walton
Accelerators. In the upgrade, both slit-type magnetron sources will be replaced
with circular aperture sources, and the Cockcroft-Waltons with a 200 MHz RFQ
(radio frequency quadrupole). Operational experience at BNL (Brookhaven
National Laboratory) has shown that the upgraded source and RFQ will be more
reliable, improve beam quality and require less manpower than the present
system.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 2011. 28 Mar - 1
Apr 2011. New York, US
A general T-matrix approach applied to two-body and three-body problems in cold atomic gases
We propose a systematic T-matrix approach to solve few-body problems with
s-wave contact interactions in ultracold atomic gases. The problem is generally
reduced to a matrix equation expanded by a set of orthogonal molecular states,
describing external center-of-mass motions of pairs of interacting particles;
while each matrix element is guaranteed to be finite by a proper
renormalization for internal relative motions. This approach is able to
incorporate various scattering problems and the calculations of related
physical quantities in a single framework, and also provides a physically
transparent way to understand the mechanism of resonance scattering. For
applications, we study two-body effective scattering in 2D-3D mixed dimensions,
where the resonance position and width are determined with high precision from
only a few number of matrix elements. We also study three fermions in a
(rotating) harmonic trap, where exotic scattering properties in terms of mass
ratios and angular momenta are uniquely identified in the framework of
T-matrix.Comment: 14 pages, 4 figure
Models of electron transport in single layer graphene
The main features of the conductivity of doped single layer graphene are
analyzed, and models for different scattering mechanisms are presented.Comment: 15 pages. Submitted to the Proceedings of the ULTI symposium on
Quantum Phenomena and Devices at Low Temperatures, Espoo, Finland, to be
published in the Journ. of Low. Temp. Phy
Integrated engineering environments for large complex products
An introduction is given to the Engineering Design Centre at the University of Newcastle upon Tyne, along with a brief explanation of the main focus towards large made-to-order products. Three key areas of research at the Centre, which have evolved as a result of collaboration with industrial partners from various sectors of industry, are identified as (1) decision support and optimisation, (2) design for lifecycle, and (3) design integration and co-ordination. A summary of the unique features of large made-to-order products is then presented, which includes the need for integration and co-ordination technologies. Thus, an overview of the existing integration and co-ordination technologies is presented followed by a brief explanation of research in these areas at the Engineering Design Centre. A more detailed description is then presented regarding the co-ordination aspect of research being conducted at the Engineering Design Centre, in collaboration with the CAD Centre at the University of Strathclyde. Concurrent Engineering is acknowledged as a strategy for improving the design process, however design coordination is viewed as a principal requirement for its successful implementation. That is, design co-ordination is proposed as being the key to a mechanism that is able to maximise and realise any potential opportunity of concurrency. Thus, an agentoriented approach to co-ordination is presented, which incorporates various types of agents responsible for managing their respective activities. The co-ordinated approach, which is implemented within the Design Co-ordination System, includes features such as resource management and monitoring, dynamic scheduling, activity direction, task enactment, and information management. An application of the Design Co-ordination System, in conjunction with a robust concept exploration tool, shows that the computational design analysis involved in evaluating many design concepts can be performed more efficiently through a co-ordinated approach
A highly divergent Encephalomyocarditis virus isolated from nonhuman primates in Singapore
10.1186/1743-422X-10-248Virology Journal10
Structural analysis of peptides that interact with Newcastle disease virus
Newcastle disease virus is a negativepolarity, single-stranded RNA virus (Lamb and Kolakofsky, 1996). It causes an economically important disease called Newcastle disease
Patterns of first-line targeted therapy utilization and adherence among older adults diagnosed with metastatic renal cell carcinoma
Background: Despite the rapid approval of targeted therapies for metastatic renal cell carcinoma (mRCC) evidence on real world treatment patterns remains limited. This study evaluated patterns of first-line targeted therapy utilization and adherence in older adults, a population with a high burden of RCC. Methods: 2093 patients aged ≥66 years with a primary diagnosis of mRCC were identified from United States (US)-based cancer registry and administrative claims data (2007–2015). We included only patients with de novo disease. We assessed the initiation of first-line targeted therapy within four months of diagnosis and persistence and adherence to targeted therapy, using the proportion of days covered (PDC). Multivariable logistic regression yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to describe characteristics associated with targeted therapy versus no targeted therapy initiation and for high (≥80% PDC) versus low adherence. Results: 28.8% of patients received first-line targeted therapy within four months of diagnosis, with the proportion of patients receiving targeted therapy increasing over time. Older age (one-year increment OR:0.95 95%CI 0.93, 0.97), high comorbidity burden (OR:0.65 95%CI0.46, 0.93) and clear cell histology (OR:1.54 95%CI 1.19, 2.00) were associated with targeted therapy initiation. 48.2% of patients exhibited a high PDC to oral targeted therapy at 120 days, which was attenuated with inclusion of patients who died during the time period (34.2% PDC ≥80%). Conclusion: Increasing age, high comorbidity burden and non-clear cell histology were associated with decreased targeted therapy initiation among patients with de novo mRCC. Our findings suggest adherence to oral therapies was low; future research exploring the mechanisms and impact of low adherence in this older patient population is warranted
Liberating Efimov physics from three dimensions
When two particles attract via a resonant short-range interaction, three
particles always form an infinite tower of bound states characterized by a
discrete scaling symmetry. It has been considered that this Efimov effect
exists only in three dimensions. Here we review how the Efimov physics can be
liberated from three dimensions by considering two-body and three-body
interactions in mixed dimensions and four-body interaction in one dimension. In
such new systems, intriguing phenomena appear, such as confinement-induced
Efimov effect, Bose-Fermi crossover in Efimov spectrum, and formation of
interlayer Efimov trimers. Some of them are observable in ultracold atom
experiments and we believe that this study significantly broadens our horizons
of universal Efimov physics.Comment: 17 pages, 5 figures, contribution to a special issue of Few-Body
Systems devoted to Efimov Physic
Thermal Resonance in Signal Transmission
We use temperature tuning to control signal propagation in simple
one-dimensional arrays of masses connected by hard anharmonic springs and with
no local potentials. In our numerical model a sustained signal is applied at
one site of a chain immersed in a thermal environment and the signal-to-noise
ratio is measured at each oscillator. We show that raising the temperature can
lead to enhanced signal propagation along the chain, resulting in thermal
resonance effects akin to the resonance observed in arrays of bistable systems.Comment: To appear in Phys. Rev.
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