Mid-infrared laser light nulling experiment using single-mode conductive waveguides

Aims: In the context of space interferometry missions devoted to the search of exo-Earths, this paper investigates the capabilities of new single mode conductive waveguides at providing modal filtering in an infrared and monochromatic nulling experiment; Methods: A Michelson laser interferometer with a co-axial beam combination scheme at 10.6 microns is used. After introducing a Pi phase shift using a translating mirror, dynamic and static measurements of the nulling ratio are performed in the two cases where modal filtering is implemented and suppressed. No additional active control of the wavefront errors is involved. Results: We achieve on average a statistical nulling ratio of 2.5e-4 with a 1-sigma upper limit of 6e-4, while a best null of 5.6e-5 is obtained in static mode. At the moment, the impact of external vibrations limits our ability to maintain the null to 10 to 20 seconds.; Conclusions: A positive effect of SM conductive waveguide on modal filtering has been observed in this study. Further improvement of the null should be possible with proper mechanical isolation of the setup.Comment: Accepted in A&A, 7 pages, 5 figure

Nitrogen flow analysis in Spain: Perspectives to increase sustainability

Nitrogen (N) is a macronutrient that, together with P and K, is vital for improving agricultural yields, but its excessive use in crop fertilisation and presence in treated wastewater and sludge are generating emissions both into the atmosphere and into natural water bodies, which leads to eutrophication events. The Haber–Bosch process is energy-intensive and it is the main chemical route to produce reactive nitrogen for the production of fertilisers. Furthermore, there is a strong dependence on imports of reactive nitrogen in Spain and Europe. For these reasons, it is necessary to propose sustainable alternatives that allow solving environmental and supply problems, in addition to proposing efficient management schemes that fit into the circular economy approach. In this context, a nitrogen flow analysis (NFA) was carried out for Spain with the year 2016 as reference. To assess some interactions and flows of N, specific sub-models were also considered for the agriculture and waste management systems. For the food and non-food flow systems, country-specific data were considered. The sectors covered were crop production (CP), animal production (AP), food processing (FP), non-food production (NF) and human consumption (HC). The results reveal a total annual import of 2142 kt N/y, of which 43 % accumulated in stocks of soils and water bodies (913 kt N/y). The largest proportion of losses was associated with emissions from agriculture (724 kt N/y to water bodies and 132 kt N/y accumulated in soils), followed by industry emissions to the atmosphere (122 kt N/y). Wastewater treatment plants (WWTPs) received around 67 kt N/y, of which 26 % was removed as biosolids and 20 % of these biosolids were recovered to be used for fertilising applications. The 49 kt N/y discharged in the final treated effluent represented 79 % of the total loss of reactive nitrogen to water bodies. In addition, an analysis of N-use efficiency and the actions required for its improvement in Spain, as well as the impact of the current diet on the N cycle, was carried out.Peer ReviewedPostprint (author's final draft

Theortetical Models of Extrasolar Giant Planets

The recent discoveries of giant planets around nearby stars have galvanized the planetary science community, astronomers, and the public at large. Since {\it direct} detection is now feasible, and is suggested by the recent acquisition of Gl229 B, it is crucial for the future of extrasolar planet searches that the fluxes, evolution, and physical structure of objects from Saturn's mass to 15 Juipter masses be theoretically investigated. We discuss our first attempts to explore the characteristics of extrasolar giant planets (EGPs), in aid of both NASA's and ESA's recent plans to search for such planets around nearby stars.Comment: LaTeX, using espcrc2.sty style files from Elsevier, 10 pages, 4 figures, to be published in the Proceedings of the International Conference on "Sources and Detection of Dark Matter in the Universe," ed. by D. Sanders et al. (Nuclear Physics B Supplement), 199

GAUCÍN (Málaga). Castillo de Gaucín. 1:980

Manuscrito firmado y rubricado por el autor. A plumilla en tinta negra y carmín y coloreado a la acuarela en siena y carmín.Indica el núcleo de población.Relación de las principales dependencias del castillo indicada por clave numérica.Se dispone además de reproducción fotográfica en negativo sobre papel

RONDA (Málaga) (Partido judicial). Caminos (1811?). 1:20.000

Manuscrito firmado y rubricado por el autor. A plumilla en tintas negra y carmín y coloreado a la acuarela en azul y carmínRelieve representado por sombreadoRelación de los principales accidentes geográficos, castillo, huertas y cañadas y núcleo de población indicada por clave numéricaSe dispone además de reproducción fotográfica en negativo sobre pape

HOSTALRICH (Gerona). Asedios. 1823 (1810). 1:10.000

Comprende los términos municipales de Hostalrich, San Felíu Busalleu y Massanas, en la provincia de LéridaFecha tomada del catálogo del SGE: "Cataluña. Provincia de Gerona. Siglos XVII a XIX". 1970, p. 610Manuscrito firmado y rubricado por el autor. A plumilla en tinta negra y coloreado a la acuarela en azul, carmín y sienaRelieve representado a trazosIndica el rodeo que hicieron los franceses (por Massanes), para evitar el castillo de Hostalrich en diciembre de 1808Relación de las poblaciones y accidentes geográficos más importantes indicada por clave numéric

Modal Filtering for Nulling Interferometry-First Single-Mode Conductive Waveguides in the Mid-Infrared

This paper presents the work achieved for the manufacturing and characterization of first single-mode waveguides to be used as modal filters for nulling interferometry in the mid-infrared range [4-20 um]. As very high dynamic range is mandatory for detection of Earth-like planets, modal filtering is one of the most stringent instrumental aspects. The hollow metallic waveguides (HMW) presented here are manufactured using micro-machining techniques. Single-mode behavior has been investigated in laboratory through a technique of polarization analysis while transmission features have been measured using flux relative comparison. The single-mode behavior have been assessed at lambda=10.6 um for rectangular waveguides with dimensions a=10 um and b<5.3 um with an accuracy of ~2.5 %. The tests have shown that a single-polarization state can be maintained in the waveguide. A comparison with results on multi-mode HMW is proposed. Excess losses of 2.4 dB (~ 58 % transmission) have been measured for a single-mode waveguide. In particular, the importance of coupling conditions into the waveguide is emphasized here. The goal of manufacturing and characterizing the first single-mode HMW for the mid-infrared has been achieved. This opens the road to the use of integrated optics for interferometry in the mentioned spectral range.Comment: 10 pages, 6 figures, accepted in A&

The effectiveness evaluation of a multimedia hepatitis C prevention program for Hispanic HIV-infected individuals

Introduction—With the introduction of highly active antiretroviral therapy the Hepatitis C virus (HCV) infection has became a primary health problem among individuals suffering from HIV/ AIDS in Puerto Rico, principally those who are injecting drug users (IDUs). A multimedia educational intervention, based on the Health Beliefs Model and Social Cognitive Theory was developed and implemented to reduce HCV associated risk behaviors among IDUs. Methods—A pre- and post- intervention study evaluated the knowledge and behavioral changes in a group of HIV-infected persons recruited from February 2006 through December 2008. Results—A total of 110 participants were recruited; all were IDUs; 82% were men; 86.3% were HIV/HCV co-infected and 24.5% had active injected drugs in the last month (prior to recruitment). The group mean age was 42.2 ± 9.2 years and mean educational level was 10th grade. Knowledge of HCV risk behaviors, perception of HCV susceptibility, and perception of disease severity increased after the intervention. Knowledge of HCV clinical manifestations and HIV co-infection complications and treatment also improved. In addition, HCV risk behaviors and injecting drug practice decrease significantly among IDUs. Conclusions—This new multimedia intervention captured and maintained the participants' attention and interest, in that way facilitating their educational process. Thus, a greater of attention and interest leads to greater knowledge and prevention improvement