739 research outputs found

    TB97: Evapotranspiration from Vegetative Surfaces in Maine

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    Diurnal evapotranspiration measurements were made over lowbush blueberries and potatoes in Maine during selected portions of the 1977 and 1978 growing seasons. Half hourly measurements were made using a Bowen ratio-energy budget method. Data from these measurements provided the principal energy budget components, an evaluation of potential evapotranspiration, and an array of diagnostic measures used to evaluate the partitioning of available energy into sensible and latent heat. Evapotranspiration rarely reached potential values and a large variability was found to exist. In an attempt to provide a reliable daily estimate of evapotranspiration from potatoes, using a minimum number of environmental measurements, the equilibrium evaporation equation of Priestly and Taylor was examined. A modified version of this equation, incorporating a soil moisture tension term to account for drying soil conditions, was established to predict daily evapotranspiration rates.https://digitalcommons.library.umaine.edu/aes_techbulletin/1104/thumbnail.jp

    Simulation of temperature and stress during and after RCC dams construction

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    The aim of this monograph is to verify the prediction of temperature and stress evolution of the finite element program COMET including the constitutive model using 1-D model. It includes the analysis of the Rialb RCC dam during and after its construction

    Do you listen to music while studying? A portrait of how people use music to optimize their cognitive performance

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    Contains fulltext : 239174.pdf (Publisher’s version ) (Open Access)The effect of background music (BGM) on cognitive task performance is a popular topic. However, the evidence is not converging: experimental studies show mixed results depending on the task, the type of music used and individual characteristics. Here, we explored how people use BGM while optimally performing various cognitive tasks in everyday life, such as reading, writing, memorizing, and critical thinking. Specifically, the frequency of BGM usage, preferred music types, beliefs about the scientific evidence on BGM, and individual characteristics, such as age, extraversion and musical background were investigated. Although the results confirmed highly diverse strategies among individuals regarding when, how often, why and what type of BGM is used, we found several general tendencies: people tend to use less BGM when engaged in more difficult tasks, they become less critical about the type of BGM when engaged in easier tasks, and there is a negative correlation between the frequency of BGM and age, indicating that younger generations tend to use more BGM than older adults. The current and previous evidence are discussed in light of existing theories. Altogether, this study identifies essential variables to consider in future research and further forwards a theory-driven perspective in the field.11 p

    Team learning in third grade arithmetic

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    Thesis (Ed.M.)--Boston Universit

    Engineering Workflow

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    Solitonic spin-liquid state due to the violation of the Lifshitz condition in Fe1+y_{1+y}Te

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    A combination of phenomenological analysis and M\"ossbauer spectroscopy experiments on the tetragonal Fe1+y_{1+y}Te system indicates that the magnetic ordering transition in compounds with higher Fe-excess, y≥y\ge 0.11, is unconventional. Experimentally, a liquid-like magnetic precursor with quasi-static spin-order is found from significantly broadened M\"ossbauer spectra at temperatures above the antiferromagnetic transition. The incommensurate spin-density wave (SDW) order in Fe1+y_{1+y}Te is described by a magnetic free energy that violates the weak Lifshitz condition in the Landau theory of second-order transitions. The presence of multiple Lifshitz invariants provides the mechanism to create multidimensional, twisted, and modulated solitonic phases.Comment: 5 pages, 2 figure

    Nano-Scale Hydroxyapatite: Synthesis, Two-Dimensional Transport Experiments, and Application for Uranium Remediation

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    Synthetic nano-scale hydroxyapatite (NHA) was prepared and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The XRD data confirmed that the crystalline structure and chemical composition of NHA correspond to Ca5OH(PO4)3. The SEM data confirmed the size of NHA to be less than 50 nm. A two-dimensional physical model packed with saturated porous media was used to study the transport characteristics of NHA under constant flow conditions. The data show that the transport patterns of NHA were almost identical to tracer transport patterns. This result indicates that the NHA material can move with water like a tracer, and its movement was neither retarded nor influenced by any physicochemical interactions and/or density effects. We have also tested the reactivity of NHA with 1 mg/L hexavalent uranium (U(VI)) and found that complete removal of U(VI) is possible using 0.5 g/L NHA at pH 5 to 6. Our results demonstrate that NHA has the potential to be injected as a dilute slurry for in situ treatment of U(VI)-contaminated groundwater systems

    Ferromagnetism and superconductivity in P-doped CeFeAsO

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    We report on superconductivity in CeFeAs1-xPxO and the possible coexistence with Ce- ferromagnetism (FM) in a small homogeneity range around x = 30% with ordering temperatures of T_SC = T_C = 4K. The antiferromagnetic (AFM) ordering temperature of Fe at this critical concentration is suppressed to T^N_Fe ~ 40K and does not shift to lower temperatures with further increase of the P concentration. Therefore, a quantum-critical-point scenario with T^N_Fe -> 0K which is widely discussed for the iron based superconductors can be excluded for this alloy series. Surprisingly, thermal expansion and X-ray powder diffraction indicate the absence of an orthorhombic distortion despite clear evidence for short range AFM Fe-ordering from muon-spin-rotation measurements. Furthermore, we discovered the formation of a sharp electron spin resonance signal unambiguously connected with the emergence of FM ordering.Comment: 5 pages, 4 figures, published in Phys. Rev. B (Rapid Communication, Editors suggestion

    PDM/PLM

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