523 research outputs found

    Constructed wetland design for produced water treatment on a colombian petroleum field

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    En el presente artículo se plantea una alternativa de solución al gran problema que enfrentan los campos de petróleo de Colombia, con respecto al manejo y disposición del agua de producción. En su mayoría, estos  campos de petróleo asumen grandes costos para el tratamiento, manejo y disposición de la misma. El artículo describe el diseño de un humedal construido a escala real, propuesto como tratamiento secundario para una posible implementación de tratamiento del agua de producción. Para el diseño se tuvieron en cuenta las características fisicoquímicas del agua afluente del campo petrolero colombiano como concentraciones de materia orgánica (DBO5) y sólidos suspendidos totales (SST), acorde con los principales criterios de diseño de la tecnología, como tipo y concentración de contaminantes, tipología de humedal, caudal de entrada y área total requerida. una vez seleccionado el tipo de humedal, el diseño contempló las variables que afectan principalmente su desempeño, incluyendo procedimientos de operación y manejo para su implementación. El diseño consistió en un Humedal Construido de  flujo Sub-Superficial Horizontal (HC fSSH) de 120.000 m2 de superficie y una profundidad de 2 ft para tratar un caudal de 678.607 Bbl/d. El HC de fSSH consistió en 60 celdas de 109,35 ft por 196,85 ft dispuestas en paralelo (12) y en serie (5), plantadas con macrófitas acuáticas nativas para potencializar los procesos de depuración. Este diseño con una gran cantidad de área superficia, se considera compensado por los bajos costos de operación y mantenimiento, calculados para un período de 10 años; Mientras que un sistema convencional de tratamiento de agua de producción en un campo petrolero, invierte 4.380.338,1 uSporan~o,unHCdefSSHoperacon23.681,78uS por año, un HC de fSSH opera con 23.681,78 uS para el mismo período de tiempo. La implementación de esta tecnología para el tratamiento de aguas residuales de la industria petrolera, se considera una alternativa viable, siempre y cuando se tengan los terrenos disponibles para su funcionamiento.  The development of this paper permits to find and set a new and alternative solution to the big problem that Colombian petroleum fields are facing: Management and Disposal of produced water. Due to the conventional treatment facilities, petroleum companies are spending great amounts of money to treat and dispose petroleum wastewaters. The present project describes a full-scale constructed wetland design proposed as a secondary treatment for a Colombian field produced water. The design takes into account the physicochemical characteristics of a Colombian field water affluent, represented as organic matter (BOD) and Total Suspended Solids (TSS) oncentrations, according to the main design criteria for the technology, like type and ollutants concentrations, type of wetland, entrance water rate and total area required. Once the type of wetland is selected, the design realizes the principal constraints that affect wetland performance, including operational and maintenance procedures for a future implementation. The design consists in a Horizontal Subsurface flow Constructed Wetland (HSSf CW) with 12 ha of superficial area and 2 ft depth, to treat an average water rate of 678.607 Bbl/day. The HSSf CW consisted on 60 cells of 109,35 x 196,85 ft each, organized in parallel (12) and in series (5). Each cell will be planted with native aquatic macrophytes to enhance purification processes. This grand superficial area design is considered compensated by the low operational and maintenance costs, calculated for a 10-year period. While a conventional treatment system for produced water needs an inversion of US4.380.338,1peryear,aHSSFCWworkswithUS4.380.338,1 per year, a HSSF CW works with US23.681,78 for the same time period

    Apophis planetary defense campaign

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    We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA's Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk

    The ABC130 barrel module prototyping programme for the ATLAS strip tracker

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    For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.Comment: 82 pages, 66 figure

    Fundamental Science and Engineering Questions in Planetary Cave Exploration

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    32 páginas.- 3 figuras.- 2 tablas.- 260 referenciasNearly half a century ago, two papers postulated the likelihood of lunar lava tube caves using mathematical models. Today, armed with an array of orbiting and fly-by satellites and survey instrumentation, we have now acquired cave data across our solar system-including the identification of potential cave entrances on the Moon, Mars, and at least nine other planetary bodies. These discoveries gave rise to the study of planetary caves. To help advance this field, we leveraged the expertise of an interdisciplinary group to identify a strategy to explore caves beyond Earth. Focusing primarily on astrobiology, the cave environment, geology, robotics, instrumentation, and human exploration, our goal was to produce a framework to guide this subdiscipline through at least the next decade. To do this, we first assembled a list of 198 science and engineering questions. Then, through a series of social surveys, 114 scientists and engineers winnowed down the list to the top 53 highest priority questions. This exercise resulted in identifying emerging and crucial research areas that require robust development to ultimately support a robotic mission to a planetary cave-principally the Moon and/or Mars. With the necessary financial investment and institutional support, the research and technological development required to achieve these necessary advancements over the next decade are attainable. Subsequently, we will be positioned to robotically examine lunar caves and search for evidence of life within Martian caves; in turn, this will set the stage for human exploration and potential habitation of both the lunar and Martian subsurface.The following funding sources are recognized for supporting several of the contributing authors: Human Frontiers Science Program grant #RGY0066/2018 (for AAB), NASA Innovative Advanced Concepts Grant #80HQTR19C0034 (HJ, UYW, and WLW), and European Research Council, ERC Consolidator Grant #818602 (AGF), the Spanish Ministry of Science and Innovation (project PID2019-108672RJ-I00) and the "Ramon y Cajal" post-doctoral contract (grant #RYC2019-026885-I (AZM)), and Contract #80NM0018D0004 between the Jet Propulsion Laboratory, California Institute of Technology and the National Aeronautics and Space Administration (AA, MJM, KU, and LK).Peer reviewe

    Altimetry for the future: Building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

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    The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

    Measurement of B-c(2S)(+) and B-c*(2S)(+) cross section ratios in proton-proton collisions at root s=13 TeV

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    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe
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