2,971 research outputs found

    Use of copper in pine nurseries

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    Copper has been used by nursery managers for more than 100 years to suppress fungi and as a fertilizer for more than 50 years. Consequently, nursery seedlings with copper deficiencies are rare, especially for broadleaf species. In many nurseries, soil contains <10 ÎŒg-Cu g-1 and in greenhouse trials, pine seedlings are relatively tolerant of soil levels with 35 ÎŒg-Cu g-1. A million bareroot pine seedlings may contain 50 to 100 g-Cu and, when soil tests indicate low copper levels, managers might apply 1 kg-Cu per million seedlings. In contrast, it may take only 15 g-Cu to produce one million container-grown seedlings. Copper fertilization is typically not required when 30 cm of applied irrigation water contains 0.1 ÎŒg-Cu g-1 (supplying 0.3 kg-Cu ha-1). This review highlights some of the past and current uses of copper in bareroot and container nurseries with a focus on deficiency and toxicity effects as well as the impact of various copper-based products and provides recommendations on ideal soil and foliar ranges

    A Genetic And Behavioral Analysis Of Mate Choice And Song Neighborhoods In Indigo Buntings

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137585/1/evo02512.pd

    Vanadium dioxide : A Peierls-Mott insulator stable against disorder

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    Vanadium dioxide undergoes a first order metal-insulator transition at 340 K. In this work, we develop and carry out state of the art linear scaling DFT calculations refined with non-local dynamical mean-field theory. We identify a complex mechanism, a Peierls-assisted orbital selection Mott instability, which is responsible for the insulating M1_1 phase, and furthermore survives a moderate degree of disorder.Comment: 5 pages, 4 figures. Supplementary material 8 pages, 4 figures. This version (v2) matches that accepted for Physical Review Letters on 16th May 201

    Synthesis, structure and tunability of zero dimensional organic-inorganic metal halides utilising the m-xylylenediammonium cation: MXD2PbI6, MXDBiI5, and MXD3Bi2Br12·2H2O

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    JLP thanks the University of St Andrews for funding and the Carnegie Trust for a Research Incentive Grant (RIG008653). We thank EPSRC for funding (EP/T019298/1 and EP/R023751/1).Over the past decade, the efficiency of photovoltaic devices based on CH3NH3PbI3 have dramatically increased. This has driven research efforts in all areas, from the discovery of materials to film processing to long-term device stability studies. Here, we report the synthesis and structure of three new “zero dimensional” organic–inorganic metal halides which use the meta-xylylenediammonium (MXD) cation: MXD2PbI6, MXDBiI5, and (MXD)3Bi2Br12·2H2O. The different structures of the new materials lead to compounds with a range of band gaps with MXDBiI5 having the lowest at 2.15 eV. We have explored the tunabilty of MXDBiI5 through halide substitution by preparing a series of samples with composition MXDBiI5–xBrx and determined the halide content using energy dispersive X-ray spectroscopy. A large range of solid solution is obtained in MXDBiI5–xBrx, resulting in the formation of single-phase materials for bromine contents from x = 0 to 3.71 (iodine contents from 1.29 to 5). This highlights the fact that zero-dimensional organic–inorganic halides are highly tunable, in a similar manner to the higher-dimensional perovskite counterparts. Such new materials open up the opportunity for further studies of the physics and optoelectronic properties of these materials.Publisher PDFPeer reviewe

    Effects of a large-scale, natural sediment deposition event on plant cover in a Massachusetts salt marsh

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    In mid-winter 2018, an unprecedented sediment deposition event occurred throughout portions of the Great Marsh in Massachusetts. Evaluation of this event in distinct marsh areas spanning three towns (Essex, Ipswich, and Newbury) revealed deposition covering 29.2 hectares with an average thickness of 30.1±2.1 mm measured shortly after deposition. While sediment deposition helps marshes survive sea level rise by building elevation, effects of such a large-scale deposition on New England marshes are unknown. This natural event provided an opportunity to study effects of large-scale sediment addition on plant cover and soil chemistry, with implications for marsh resilience. Sediment thickness did not differ significantly between winter and summer, indicating sediment is not eroding or compacting. The deposited sediment at each site had similar characteristics to that of the adjacent mudflat (e.g., texture, bivalve shells), suggesting that deposited materials resulted from ice rafting from adjacent flats, a natural phenomenon noted by other authors. Vegetative cover was significantly lower in plots with rafted sediment (75.6±2.3%) than sediment-free controls (93.1±1.6%) after one growing season. When sorted by sediment thickness categories, the low thickness level (1–19 mm) had significantly greater percent cover than medium (20–39 mm) and high (40–90 mm) categories. Given that sediment accretion in the Great Marsh was found to average 2.7 mm per year, the sediment thickness documented herein represents ~11 years of sediment accretion with only a 25% reduction in plant cover, suggesting this natural sediment event will likely increase long-term marsh resilience to sea level rise

    Room temperature exsolution of CdS nanodots on A-site deficient cotton-ball like titanate perovskite nanoparticles for H2 production under visible light

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    Funding: The authors thank EPSRC for funding for a Critical Mass Project EP/R023522/1 and electron microscopy facilities EP/R023751/1 and EP/L017008/1.Exsolution of nanoparticles followed by chemical treatment (“chemistry at a point”) is a very exciting approach to the smart design of functional materials such as visible light active photocatalysts. Unfortunately, the usually utilized thermal reduction approach is not feasible for low melting point metals and compounds such as Cd and CdO. Here a hydrothermal approach to prepare exsolved CdS nanodots on cotton ball-like perovskite supports is described. The titanate-based photocatalyst is synthesized using a hydrothermal process followed by room-temperature sulfidation. The hydrothermal route directs A-site doping of Cd2+ via hydroxyl group incorporation in the titanate lattice. Formation of CdS via exsolution provides a high H2 production mass activity of 3050 ”mol g−1 h−1 under visible light with only 5 mol.% Cd doping of the titanate. Moreover, the strong CdS-support interaction offers good cycling stability under UV–vis and visible light irradiation. This is the first report describing the exsolution of CdS nanodots at room temperature and shows its advantages for photocatalytic activity.Publisher PDFPeer reviewe

    Intact implicit processing of facial threat cues in schizophrenia

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    An emerging body of research suggests that people with schizophrenia retain the ability to implicitly perceive facial affect, despite well-documented difficulty explicitly identifying emotional expressions. It remains unclear, however, whether such functional implicit processing extends beyond emotion to other socially relevant facial cues. Here, we constructed two novel versions of the Affect Misattribution Procedure, a paradigm in which affective responses to primes are projected onto neutral targets. The first version included three face primes previously validated to elicit varying inferences of threat from healthy individuals via emotion-independent structural modification (e.g., nose and eye size). The second version included the threat-relevant emotional primes of angry, neutral, and happy faces. Data from 126 participants with schizophrenia and 84 healthy controls revealed that although performing more poorly on an assessment of explicit emotion recognition, patients showed normative implicit threat processing for both non-emotional and emotional facial cues. Collectively, these results support recent hypotheses postulating that the initial perception of salient facial information remains intact in schizophrenia, but that deficits arise at subsequent stages of contextual integration and appraisal. Such a breakdown in the stream of face processing has important implications for mechanistic models of social cognitive impairment in schizophrenia and treatment strategies aiming to improve functional outcome

    Performance evaluation of single carrier 40-Gbit/s downstream for long-reach passive optical network

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    This paper presents a new long reach PON (LR-PON) scenario operating at a single carrier of 40-Gbit/s for downstream, as an upgrade option of the LR-PON evolutionary strategy. An electrical 3-level duobinary modulation format was proposed for the 40-Gbit/s downstream transmission. In this paper the required optical signal to noise ratio (OSNR) and optical power budget were investigated based on analytic calculation of OSNR requirements and cascaded analysis with an optical link model. Numerical simulation results show that the 40-Gbit/s downstream operating at the wavelength of 1.5 ÎŒm can support a long reach up to 100 km and a high split ratio up to 256

    Panel Discussion: Ideas for an Enjoyable and Productive Sabbatical

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    Navigating the Sabbatical Process and Deciding on a Productive Activity Can Be Challenging. a Sabbatical Can Take Many Different Forms Depending on Career Goals, Interests, and Institution. the Purpose of This Panel Discussion is to Provide Faculty Who Have Yet to Conduct a Sabbatical with Ideas of Activities and the Process. a Variety of Personal Experiences Will Be Presented of Sabbatical Activities that Were Enjoyable and Productive. These May Include Sabbaticals Focused on Independent Engineering Research, Engineering Education Research, Development of Classes or Programs, Industry or Government Collaboration, And/or Travel. Discussion Topics Will Also Include Process Requirements of Applying, Conducting, and Documenting the Outcomes of the Sabbatical. the Suggested Layout of the Panel Session Is: ‱ 5-Minute Introduction of Panel Topic and Panelists ‱ overview of Each Panelist\u27s Sabbatical Activity (5 Minutes Each) ‱ Brief Whole Group Q&A Session to Engage Audience and Panelists ‱ Small Group Activities with Documentation of Q&A: O What Resources Did You Find Helpful in Planning Your Sabbatical? O What Was the Timeframe of Planning, Applying For, Conducting, and Documenting Your Sabbatical? O What Were the Requirements of Your Sabbatical? O When or How Often Have You Conducted a Sabbatical? ‱ Bring Whole Group Back Together to Discuss Learnings
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