Temporal Passage: A Shape-Dynamic Account

Special issue: Current Issues in Metaphysics

Transverse instability of the antiproton beam in the Recycler Ring

The brightness of the antiproton beam in Fermilab's 8 GeV Recycler ring is limited by a transverse instability. This instability has occurred during the extraction process to the Tevatron for large stacks of antiprotons even with dampers in operation. This paper describes observed features of the instability, introduces the threshold phase density to characterize the beam stability, and finds the results to be in agreement with a resistive wall instability model. Effective exclusion of the longitudinal tails from Landau damping by decreasing the depth of the RF potential well is observed to lower the threshold density by up to a factor of two.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 2011. 28 Mar - 1 Apr 2011. New York, US

Unmet depression information needs in the community

Background Despite the well acknowledged importance of consumer health information, little is known about the public’s depression information needs. This study aimed to develop a formal measure of unmet need for depression information in the community, to investigate the level of this unmet need and to identify its predictors. Methods Data were collected as part of a survey of 12,319 Australian adults aged 18–65 years. This survey incorporated 21 questions targeting depression information need, together with measures of demographic status, self-reported current depression and personal stigma. The information needs data were subjected to principal components analysis followed by linear regression analyses to determine the demographic and other predictors of each of the resulting components. Results Between 50 and 75% of participants endorsed the need for more information on each of the 21 information need topics. The PCA yielded a 20-item Depression Information Needs Scale (DINS) of high reliability and factor validity comprising four subscales: General (facts about depression), Specific Treatments, Research and Policies, and Lived Experience. Controlling for other factors, those with self-reported current depression and those without tertiary education had greater information needs across all four factors. Limitations The survey response rate was low and further research is required to establish the adequacy of the psychometric properties of the DINS. Conclusions Given the high unmet need for depression information there is a need to develop and implement evidence-based strategies for ensuring the accessibility and uptake of depression information relevant to the needs of members of the community.This study was funded by a National Health and Medical Research Council (NHMRC) Project Grant 471435. K.G. is supported by NHMRC Fellowship no. 525413. The funding body played no further role in any aspect of this study

Embedding right-angled Artin groups into graph braid groups

We construct an embedding of any right-angled Artin group $G(\Delta)$ defined by a graph $\Delta$ into a graph braid group. The number of strands required for the braid group is equal to the chromatic number of $\Delta$. This construction yields an example of a hyperbolic surface subgroup embedded in a two strand planar graph braid group.Comment: 8 pages. Final version, appears in Geometriae Dedicata

Antennas for wide area distributed RFID systems

© 2020 IEEE. This paper describes the use of Wide Area Distributed RFID Systems to enable wide area coverage of UHF RFID with high likelihood of tags anywhere within the area being successfully detected. The implications on antenna design are discussed and novel loop antenna meeting the requirements is presented

Power margin reduction in linear passive UHF RFID tag arrays

This paper studies the power margin reduction in linear passive UHF RFID tag arrays due to proximity effects. It is shown experimentally that a 40% reduction in tag power margin occurs when two tags are placed with a separation of less than 2cm. Major causes of tag sensitivity degradation due to proximity in arrays are analyzed by experiment and simulation, including tag detuning, shadowing and re-emission cancellation. It is shown that tag detuning has a significant effect when tags are separated by less than 7mm. At larger separations in excess of 1cm, the tag shadowing effect and interactions between the backscattered waves cause more significant degradation for large tag arrays.This work has been supported by UK Engineering and Physical Science Research Council via the COPOSII project.This is the author accepted manuscript. The final version is available at http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=6934248