138 research outputs found

    Cosmic-ray neutron probes on the high plains of Nebraska: applications to large scale agriculture

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    Cosmic-rays have some surprising applications in precision agriculture. The cosmic-ray neutron probe (CRNP), when implemented as a roving instrument, can be used to create spatial maps of soil moisture, and from these maps soil hydraulic properties can be inferred. In this work, we combine data from a mobile CRNP with laboratory samples to make spatial predictions of soil hydraulic properties for select field sites around the state of Nebraska. These maps, which focus on wilting point and field capacity, can, in turn, be used to determine the optimal timing and application rates for irrigation farmers, many of whom have the capability to finely tune the spatial distribution of water applied on a field, but currently lack the requisite data to support such management practices. We find that 4 CRNP soil moisture maps are adequate to describe the dominant underlying spatial structure of the field (\u3e75% of variability) using Empirical Orthogonal Functions. The CRNP soil moisture maps combined with an elevation layer provided strong statistical predictors of laboratory measured soil hydraulic properties. The economic viability of the method depends on numerous local cost factors but rising demand for water resources may dictate the need for innovative approaches such as this one to reduce future water use

    Magnetic structure of the antiferromagnetic half-Heusler compound NdBiPt

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    We present results of single crystal neutron diffraction experiments on the rare-earth, half-Heusler antiferromagnet (AFM) NdBiPt. This compound exhibits an AFM phase transition at TN=2.18T_{\mathrm N}=2.18~K with an ordered moment of 1.78(9)1.78(9)~μB\mu_{\mathrm B} per Nd atom. The magnetic moments are aligned along the [001][001]-direction, arranged in a type-I AFM structure with ferromagnetic planes, alternating antiferromagnetically along a propagation vector τ\tau of (100)(100). The RRBiPt (RR= Ce-Lu) family of materials has been proposed as candidates of a new family of antiferromagnetic topological insulators (AFTI) with magnetic space group that corresponds to a type-II AFM structure where ferromagnetic sheets are stacked along the space diagonal. The resolved structure makes it unlikely, that NdBiPt qualifies as an AFTI.Comment: As resubmitted to PRB, corrected typos and changed symbols in Fig.

    Direct observation of the quantum critical point in heavy fermion CeRhSi3_3

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    We report on muon spin rotation studies of the noncentrosymmetric heavy fermion antiferromagnet CeRhSi3_3. A drastic and monotonic suppression of the internal fields, at the lowest measured temperature, was observed upon an increase of external pressure. Our data suggest that the ordered moments are gradually quenched with increasing pressure, in a manner different from the pressure dependence of the N\'eel temperature. At \unit{23.6}{kbar}, the ordered magnetic moments are fully suppressed via a second-order phase transition, and TNT_{\rm{N}} is zero. Thus, we directly observed the quantum critical point at \unit{23.6}{kbar} hidden inside the superconducting phase of CeRhSi3_3

    Using Cosmic-Ray Neutron Probes to Monitor Landscape Scale Soil Water Content in Mixed Land Use Agricultural Systems

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    With an ever-increasing demand for natural resources and the societal need to understand and predict natural disasters, soil water content (SWC) observations remain a critical variable to monitor in order to optimally allocate resources, establish early warning systems, and improve weather forecasts.However, routine agricultural production practices of soil cultivation, planting, and harvest make the operation andmaintenance of direct contact point sensors for long-termmonitoring challenging. In this work, we explore the use of the newly established Cosmic-Ray Neutron Probe (CRNP) and method to monitor landscape average SWC in a mixed agricultural land use systemin northeastAustria.Thecalibrated CRNP landscape SWC values compare well against an independent in situ SWC probe network (MAE = 0.0286m3/m3) given the challenge of continuous in situ monitoring from probes across a heterogeneous agricultural landscape. The ability of the CRNP to provide real-time and accurate landscape SWC measurements makes it an ideal method for establishing long-term monitoring sites in agricultural ecosystems to aid in agricultural water and nutrient management decisions at the small tract of land scale as well as aiding in management decisions at larger scales

    Comment on ‘Examining the variation of soil moisture from cosmic‑ray neutron probes footprint: experimental results from a COSMOS‑UK site’ by Howells, O.D., Petropoulos, G.P., et al., Environ Earth Sci 82, 41 (2023)

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    The published article by Howells et al. (2023) attempts to empirically derive the lateral footprint for a single cosmic-ray neutron sensor (CRNS), which is part of the COSMOS-UK network (Evans et al. 2016). The main result is the “true” footprint to be 50 m in radius, substantially smaller than previously published estimates. Their conclusion contradicts more than 15 peer-reviewed studies and more than a decade of research on the subject conducted by various international research groups, and thus, it would be considered as a ground-breaking finding if the methods were scientifically sound. However, the methods and arguments presented by the authors have major errors and the presented conclusions are consequently wrong

    The Grizzly, December 3, 1982

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    Graterford Prisoners Counseled • Phi Psi Sponsors Santa • Chem Society Rated Outstanding • Renowned Professor Dies • Steinbright Scholarships Offered • News Briefs: Sigma Pi Sigma Inducts New Members; Operation Native Talent; New Evening School Class; Winterfest II Schedules Events; Going for Baroque • Commuters Don\u27t Get No Respect! • Letters to the Editor • Is Tuition Increase Justified? • Recent Thefts and Attacks Prompt Security Questions • Cheating at Ursinus? • A Last Squeeze Before Departing • The Missionary: A Blessing • Roving Reporter: How Do You Feel About the New Security System in the Quad? • Challenge Yourself at Outward Bound • The Perfect Man • UC Faculty Not Burnt Out • Sports Profile: Mullahy and Bazow, Football Captains • Women\u27s Basketball Tops Aggies in Opener: Jankauskas Scoring and Rebounding Was Key • UC Making a Contribution to Olympic Efforthttps://digitalcommons.ursinus.edu/grizzlynews/1090/thumbnail.jp

    On the application of the factsage thermochemical software and databases in materials science and pyrometallurgy

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    ABSTRACT: The discovery of new metallic materials is of prime importance for the development of new technologies in many fields such as electronics, aerial and ground transportation as well as construction. These materials require metals which are obtained from various pyrometallurgical processes. Moreover, these materials need to be synthesized under extreme conditions of temperature where liquid solutions are produced and need to be contained. The design and optimization of all these pyrometallurgical processes is a key factor in this development. We present several examples in which computational thermochemistry is used to simulate complex pyrometallurgical processes including the Hall–Heroult process (Al production), the PTVI process (Ni production), and the steel deoxidation from an overall mass balance and energy balance perspective. We also show how computational thermochemistry can assist in the material selection in these extreme operation conditions to select refractory materials in contact with metallic melts. The FactSage thermochemical software and its specialized databases are used to perform these simulations which are proven here to match available data found in the literature

    A prospective cohort study of dietary patterns of non-western migrants in the Netherlands in relation to risk factors for cardiovascular diseases: HELIUS-Dietary Patterns

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    <p>Abstract</p> <p>Background</p> <p>In Western countries the prevalence of cardiovascular disease (CVD) is often higher in non-Western migrants as compared to the host population. Diet is an important modifiable determinant of CVD. Increasingly, dietary patterns rather than single nutrients are the focus of research in an attempt to account for the complexity of nutrient interactions in foods. Research on dietary patterns in non-Western migrants is limited and may be hampered by a lack of validated instruments that can be used to assess the habitual diet of non-western migrants in large scale epidemiological studies. The ultimate aims of this study are to (1) understand whether differences in dietary patterns explain differences in CVD risk between ethnic groups, by developing and validating ethnic-specific Food Frequency Questionnaires (FFQs), and (2) to investigate the determinants of these dietary patterns. This paper outlines the design and methods used in the HELIUS-Dietary Patterns study and describes a systematic approach to overcome difficulties in the assessment and analysis of dietary intake data in ethnically diverse populations.</p> <p>Methods/Design</p> <p>The HELIUS-Dietary Patterns study is embedded in the HELIUS study, a Dutch multi-ethnic cohort study. After developing ethnic-specific FFQs, we will gather data on the habitual intake of 5000 participants (18-70 years old) of ethnic Dutch, Surinamese of African and of South Asian origin, Turkish or Moroccan origin. Dietary patterns will be derived using factor analysis, but we will also evaluate diet quality using hypothesis-driven approaches. The relation between dietary patterns and CVD risk factors will be analysed using multiple linear regression analysis. Potential underlying determinants of dietary patterns like migration history, acculturation, socio-economic factors and lifestyle, will be considered.</p> <p>Discussion</p> <p>This study will allow us to investigate the contribution of the dietary patterns on CVD risk factors in a multi-ethnic population. Inclusion of five ethnic groups residing in one setting makes this study highly innovative as confounding by local environment characteristics is limited. Heterogeneity in the study population will provide variance in dietary patterns which is a great advantage when studying the link between diet and disease.</p
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