1,876 research outputs found

    A New Type of distributed Enamel based Clearing Electrode

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    Clearing electrodes can be used for electron cloud (EC) suppression in high intensity particle accelerators. In this paper the use of low and highly resistive layers on a dielectric substrate are examined. The beam coupling impedance of such a structure is evaluated. Furthermore the clearing efficiency as well as technological issues are discussed

    Context-Awareness at the Service of Sensor Fusion Systems: Inverting the Usual Scheme

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    Proceedings of: 11th International Work-Conference on Artificial Neural Networks (IWANN 2011). International Workshop of Intelligent systems for context-based information fusion (ISCIF 11). Torremolinos-Málaga, Spain, June 8-10, 2011Many works on context-aware systems make use of location, navigation or tracking services offered by an underlying sensor fusion module, as part of the relevant contextual information. The obtained knowledge is typically consumed only by the high level layers of the system, in spite that context itself represents a valuable source of information from which every part of the implemented system could take benefit. This paper closes the loop, analyzing how can context knowledge be applied to improve the accuracy, robustness and adaptability of sensor fusion processes. The whole theoretical analysis will be related with the indoor/outdoor navigation system implemented for a wheeled robotic platform. Some preliminary results are presented, where the context information provided by a map is integrated in the sensor fusion system.This work was supported in part by Projects ATLANTIDA, CICYT TIN2008-06742-C02-02/TSI, CICYT TEC2008-06732-C02-02/TEC, SINPROB, CAM MADRINET S-0505/TIC/0255 DPS2008-07029-C02-02.Publicad

    Genetic Diversity in Hypericum and AFLP Markers for Species-Specific Identification of H. perforatum L.

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    One of the top-selling medicinal products worldwide is Hypericum perforatum (St. John\u27s Wort). Despite its cosmopolitan distribution and utilization, little is known regarding the relationship of the bioactive compounds in H. perforatum to the plants from which they are purportedly derived. In this study, amplified fragment length polymorphism (AFLP) analysis of 56 Hypericum accessions, representing 11 species, was conducted to gain a better understanding of diversity within Hypericum species, especially within cultivated accessions of H. perforatum, and to establish a molecular methodology that will provide breeders and regulators with a simple, affordable, and accurate tool with which to identify purported H. perforatummaterial. Utilizing four primer combinations, a total of 298 polymorphic markers were generated, of which 17 were present in all H. perforatum accessions and 2 were specific to only H. perforatum. This study demonstrates that AFLP can be utilized not only to determine the relationships of closely related Hypericumaccessions, but as a tool to authenticate material in herbal remedies through the use of genetic fingerprinting

    Molecular confirmation of species status for the allopolyploid cotton species, Gossypium ekmanianum Wittmack.

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    Understanding the relationship between domesticated crop species and their wild relatives is paramount to germplasm maintenance and the utilization of wild relatives in breeding programs. Recently, Gossypium ekmanianum was resurrected as an independent species based on morphological analysis of specimens obtained from the Dominican Republic, where the original type specimen was collected. The molecular data presented here support the recognition of G. ekmanianum Wittmack as a distinct species that is phylogenetically close to G. hirsutum L. Analyses of chloroplast DNA data reveal species-specific, indel polymorphisms that unambiguously distinguish G. ekmanianum samples from other polyploid congeners. Furthermore, analysis of accessions that originated from the Dominican Republic demonstrate the cryptic inclusion of this sister taxon within the US National Plant Germplasm System, a germplasm collection maintained for diversity preservation and future breeding resources. The data presented here indicate that ‘‘wild’’ G. hirsutum accessions may include the closely related G. ekmanianum, and provide a method to easily distinguish the two.Fil: Grover, C. E.. University of Iowa; Estados UnidosFil: Zhu, X.. Nantong University; ChinaFil: Grupp, K. K.. University Of Iowa; Estados UnidosFil: Jareczek, J. J.. University of Iowa; Estados UnidosFil: J. P. Gallagher. University of Iowa; Estados UnidosFil: Szadkowski, E.. University of Iowa; Estados UnidosFil: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; ArgentinaFil: Wendel, J. F.. University of Iowa; Estados Unido

    The {\eta}'-carbon potential at low meson momenta

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    The production of η\eta^\prime mesons in coincidence with forward-going protons has been studied in photon-induced reactions on 12^{12}C and on a liquid hydrogen (LH2_2) target for incoming photon energies of 1.3-2.6 GeV at the electron accelerator ELSA. The η\eta^\prime mesons have been identified via the ηπ0π0η6γ\eta^\prime\rightarrow \pi^0 \pi^0\eta \rightarrow 6 \gamma decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF2_2 array at polar angles of 2θp112^{\circ} \le \theta _{p} \le 11^{\circ}. Under these kinematic constraints the η\eta^\prime mesons are produced with relatively low kinetic energy (\approx 150 MeV) since the coincident protons take over most of the momentum of the incident-photon beam. For the C-target this allows the determination of the real part of the η\eta^\prime-carbon potential at low meson momenta by comparing with collision model calculations of the η\eta^\prime kinetic energy distribution and excitation function. Fitting the latter data for η\eta^\prime mesons going backwards in the center-of-mass system yields a potential depth of V = -(44 ±\pm 16(stat)±\pm15(syst)) MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average η\eta^\prime momenta of \approx 1.1 GeV/cc. Within the experimental uncertainties, there is no indication of a momentum dependence of the η\eta^\prime-carbon potential. The LH2_2 data, taken as a reference to check the data analysis and the model calculations, provide differential and integral cross sections in good agreement with previous results for η\eta^\prime photoproduction off the free proton.Comment: 9 pages, 13 figures. arXiv admin note: text overlap with arXiv:1608.0607

    A pilot field evaluation on heat stress in sugarcane workers in Costa Rica: What to do next?

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    BACKGROUND: Climate change is producing major impacts including increasing temperatures in tropical countries, like Costa Rica, where the sugarcane industry employs thousands of workers who are exposed to extreme heat. OBJECTIVES: This article outlines a pilot qualitative evaluation of working conditions and heat in the sugarcane industry. DESIGN: A literature review, direct observations and exploratory interviews with workers were conducted to reach a preliminary understanding of the dimensions of heat-related health issues in the sugarcane industry, as a basis for the design of future studies. RESULTS: The industry employs temporary workers from Nicaragua and Costa Rica as well as year-round employees. Temporary employees work 12-hour shifts during the harvest and processing ('zafra') season. In many cases, sugarcane field workers are required to carry their own water and often have no access to shade. Sugar mill workers are exposed to different levels of heat stress depending upon their job tasks, with the most intense heat and workload experienced by the oven ('caldera') cleaners. CONCLUSIONS: Research is needed to achieve better understanding of the multiple factors driving and interacting with heat exposures in the sugarcane industry in order to improve the health and safety of workers while maintaining worker productivity
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