3,475 research outputs found

    Neutrino oscillations in matter of varying density

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    We consider two-family neutrino oscillations in a medium of continuously-varying density as a limit of the process in a series of constant-density layers. We construct analytic expressions for the conversion amplitude at high energies within a medium with a density profile that is piecewise linear. We compare some cases to understand the type of effects that depend on the order of the material traversed by a neutrino beam.Comment: 10 page

    Sustainable Forest Bioenergy Development Strategies in Indochina: Collaborative Effort to Establish Regional Policies

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    We conducted a feasibility study in Indochina (Cambodia, Laos, Myanmar, Thailand, and Vietnam) with the aim of promoting biomass and bioenergy markets, technology transfer, rural development, and income generation. Policy development is guided by the International Union of Forest Research Institutions (IUFRO) Task Force “Sustainable Forest Bioenergy Network”. In this paper, we highlight the achievements up to now and present results of a multi-stakeholder questionnaire in combination with a quantitative analysis of the National Bioenergy Development Plans (NBDPs). We found a gap between official documents and working group assessments. NBDPs are focused on the market development, technology transfer, and funding possibilities of a regional bioenergy strategy, while the respondents of a questionnaire (working groups) favored more altruistic goals, i.e., sustainable resource management, environmental protection and climate change mitigation, generation of rural income, and community involvement, etc. We therefore suggest the following measures to ensure regulations that support the original aims of the network (climate change mitigation, poverty alleviation, sustainable resource use, and diversification of energy generation): (i) Consideration of science-based evidence for drafting bioenergy policies, particularly in the field of biomass production and harvesting; (ii) invitation of stakeholders representing rural communities to participate in this process; (iii) development of sustainability criteria; (iv) feedback cycles ensuring more intensive discussion of policy drafts; (v) association of an international board of experts to provide scientifically sound feedback and input; and (vi) establishment of a local demonstration region, containing various steps in the biomass/bioenergy supply chain including transboundary collaboration in the ACMECS region

    Unlocking Insights into Crop Growth and Nutrient Distribution: A Geospatial Analysis Approach Using Satellite Imagery and Soil Data

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    Accurate monitoring of crop growth and nutrient distribution is crucial for optimizing agricultural practices, promoting a sustainable environment, and ensuring long-term food production. In this study, we propose a novel and comprehensive approach to monitor crop growth and nutrient distribution in large-scale agricultural landscapes. Our methodology combines advanced geospatial and temporal analysis techniques, providing valuable insights into the intricate relationships between crop health, soil nutrients, and other essential soil properties. To monitor vegetation dynamics, we obtained data from the IBM EIS (Environment Intelligence Suite) and processed it using our HPC (High-Performance Computing) infrastructure. This is ingested into our CRADLE (Common Research Analytics and Data Lifecycle Environment). The IBM EIS consists of vast amounts of geospatial data curated from diverse sources, readily available for analysis. Leveraging the Normalized Difference Vegetation Index (NDVI) algorithm and MODIS Aqua satellite imagery, we classified vegetation on a daily basis, yielding a detailed assessment of land use and growth. Additionally, by integrating MODIS Aqua data with USDA Historical Crop planting data, we can identify the dominant crops in each region and monitor their growth and health across Texas and Ohio during 2019. To investigate soil properties and their influence on crop health, we utilize prominent soil databases from IBM EIS such as The Soil Survey Geographic Database (SSURGO) and the World Soil Information Service (WoSIS). These databases provide essential information on key soil properties, including pH, texture, water holding capacity, and organic carbon. By correlating these properties with soil nitrogen content, we can assess their interdependencies and infer their impacts on crop health. Furthermore, we analyze the correlation between crop health and nitrogen content, gaining valuable insights into the effects of soil nitrogen on crop well-being. By integrating remote sensing technology, soil science, and data science, this interdisciplinary study contributes to the development of sustainable agricultural management strategies. The findings of this research enhance food production capabilities and provide valuable information for policy decision-making, ultimately promoting environmental conservation within large-scale agricultural systems

    Thirty-two Goldbach Variations

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    We give thirty-two diverse proofs of a small mathematical gem--the fundamental Euler sum identity zeta(2,1)=zeta(3) =8zeta(\bar 2,1). We also discuss various generalizations for multiple harmonic (Euler) sums and some of their many connections, thereby illustrating both the wide variety of techniques fruitfully used to study such sums and the attraction of their study.Comment: v1: 34 pages AMSLaTeX. v2: 41 pages AMSLaTeX. New introductory material added and material on inequalities, Hilbert matrix and Witten zeta functions. Errors in the second section on Complex Line Integrals are corrected. To appear in International Journal of Number Theory. Title change

    Harmonic Sums and Mellin Transforms up to two-loop Order

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    A systematic study is performed on the finite harmonic sums up to level four. These sums form the general basis for the Mellin transforms of all individual functions fi(x)f_i(x) of the momentum fraction xx emerging in the quantities of massless QED and QCD up to two--loop order, as the unpolarized and polarized splitting functions, coefficient functions, and hard scattering cross sections for space and time-like momentum transfer. The finite harmonic sums are calculated explicitly in the linear representation. Algebraic relations connecting these sums are derived to obtain representations based on a reduced set of basic functions. The Mellin transforms of all the corresponding Nielsen functions are calculated.Comment: 44 pages Latex, contract number adde
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