1,981 research outputs found

    Coalescing at 8 GeV in the Fermilab Main Injector

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    For Project X, it is planned to inject a beam of 3 10**11 particles per bunch into the Main Injector. To prepare for this by studying the effects of higher intensity bunches in the Main Injector it is necessary to perform coalescing at 8 GeV. The results of a series of experiments and simulations of 8 GeV coalescing are presented. To increase the coalescing efficiency adiabatic reduction of the 53 MHz RF is required, resulting in ~70% coalescing efficiency of 5 initial bunches. Data using wall current monitors has been taken to compare previous work and new simulations for 53 MHz RF reduction, bunch rotations and coalescing, good agreement between experiment and simulation was found. Possible schemes to increase the coalescing efficiency and generate even higher intensity bunches are discussed. These require improving the timing resolution of the low level RF and/or tuning the adiabatic voltage reduction of the 53 MHz.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012) 20-25 May 2012, New Orleans, Louisian

    Resolving the identification of weak-flying insects during flight: a coupling between rigorous data processing and biology

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    1. Bioacoustic methods play an increasingly important role for the detection of insects in a range of surveillance and monitoring programs. 2. Weak-flying insects evade detection because they do not yield sufficient audio information to capture wingbeat and harmonic frequencies. These inaudible insects often pose a significant threat to food security as pests of key agricultural crops worldwide. 3. Automatic detection of such insects is crucial to the future of crop protection by providing critical information to assess the risk to a crop and the need for preventative measures. 4. We describe an experimental setup designed to derive audio recordings from a range of weak-flying aphids and beetles using an LED array. 5. A rigorous data processing pipeline was developed to extract meaningful features, linked to morphological characteristics, from the audio and harmonic series for six aphid and two beetle species. 6. An ensemble of over 50 bioacoustic parameters was used to achieve species discrimination with a success rate of 80%. The inclusion of the dominant and fundamental frequencies improved prediction between beetles and aphids due to large differences in wingbeat frequencies. 7. At the species level, error rates were minimised when harmonic features were supplemented by features indicative of differences in species’ flight energies

    Novel food-safe spin-lattice relaxation time calibration samples for use in magnetic resonance sensor development

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    Magnetic Resonance (MR) sensors are an area of increasing interest for the measurement and monitoring of material properties. There are two relaxation times associated with samples that can be measured with MR sensors: The spin-lattice and spin-spin relaxations. When developing new sensors, it is desirable to have a series of standards by which instruments can be assessed. The standard calibration materials available typically comprise different concentrations of Nickel Sulphate, which is carcinogenic and toxic. In this work, we report the use of solutions containing full fat milk powder as a safe and inexpensive material that shortens the longitudinal relaxation time of water over a wide range of values. We demonstrate that concentrations in distilled water from 5% W/V to 64% W/V give T1 values from 1.7 s down to 469 ms respectively in a 1.5T clinical MRI, while within an MR sensor, these times were from 1.6 s down to 431 ms. In addition, both systems have the same exponential coefficient (-0.022*concentration) that demonstrates the effectiveness of the NMR sensor in comparison to the clinical MRI

    Is Visual Selective Attention in Deaf Individuals Enhanced or Deficient? The Case of the Useful Field of View

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    BACKGROUND: Early deafness leads to enhanced attention in the visual periphery. Yet, whether this enhancement confers advantages in everyday life remains unknown, as deaf individuals have been shown to be more distracted by irrelevant information in the periphery than their hearing peers. Here, we show that, in a complex attentional task, a performance advantage results for deaf individuals. METHODOLOGY/PRINCIPAL FINDINGS: We employed the Useful Field of View (UFOV) which requires central target identification concurrent with peripheral target localization in the presence of distractors - a divided, selective attention task. First, the comparison of deaf and hearing adults with or without sign language skills establishes that deafness and not sign language use drives UFOV enhancement. Second, UFOV performance was enhanced in deaf children, but only after 11 years of age. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that, following early auditory deprivation, visual attention resources toward the periphery slowly get augmented to eventually result in a clear behavioral advantage by pre-adolescence on a selective visual attention task

    Elementary processes governing the evolution of road networks

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    Urbanisation is a fundamental phenomenon whose quantitative characterisation is still inadequate. We report here the empirical analysis of a unique data set regarding almost 200 years of evolution of the road network in a large area located north of Milan (Italy). We find that urbanisation is characterised by the homogenisation of cell shapes, and by the stability throughout time of high-centrality roads which constitute the backbone of the urban structure, confirming the importance of historical paths. We show quantitatively that the growth of the network is governed by two elementary processes: (i) `densification', corresponding to an increase in the local density of roads around existing urban centres and (ii) `exploration', whereby new roads trigger the spatial evolution of the urbanisation front. The empirical identification of such simple elementary mechanisms suggests the existence of general, simple properties of urbanisation and opens new directions for its modelling and quantitative description.Comment: 10 pages, 6 figure

    Risk Indicators for Periodontitis in US Adults: NHANES 2009 to 2012

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142205/1/jper1174.pd
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