179 research outputs found
Primeros registros para Portugal del inductor de agallas foliares Cystiphora sonchi (Vallot, 1827) (Diptera: Cecidomyiidae) y algunas notas sobre su distribución en la Península Ibérica
One frequent limitation in zoology and ecology studies is that the current spatial distribution of several species is only partially assessed, based on museum or amateurs’ records, underestimating the real distribution of the species. Although this limitation could be partially solved by different tools (e.g., species distribution models), the correct functioning of many of such tools is related to the number of occurrences, requiring a minimum number of occurrences to be correctly validated. The genus Cystiphora Kieffer, 1892 (Diptera: Cecidomyiidae) has three species in the Iberian Peninsula and is mainly characterized by the induction of galls in species of sow-thistle (Sonchus spp.); this genus has an added value since some species are used as biocontrol against invasive sow-thistles in the Nearctic and Australasian regions. However, little is known about its actual distribution in Iberia. Cystiphora sonchi (Vallot, 1827) is a Palearctic species whose presence in Iberia Peninsula was until now restricted to four records in the East of Peninsula and in the Balearic Islands. We found three new populations of this species in Coimbra, central Portugal, adding a new species to the Portuguese fauna. Additionally, in order to complete as much as possible its current spatial distribution, a methodical search was carried in different Biodiversity Databases. These two approaches, expanded the distribution area of C. sonchi in the Iberian Peninsula, with five new occurrences (three for Portugal, one for Galicia and one for Andalusia) and establishing a new west limit in the current distribution of C. sonchi in the Palearctic region.Un problema habitual en los estudios de zoología y ecología es la evaluación parcial de la distribución espacial actual de muchas especies, pues subestima su distribución real al estar basada en los registros de naturalistas y de museos. Aunque esta limitación puede ser parcialmente resuelta por medio de diferentes herramientas (p.e. modelos de distribución de especies), el correcto funcionamiento de dichas herramientas está condicionado por el número de localizaciones disponibles, necesitando además de un número mínimo de ellas para que los modelos puedan ser validados. El género Cystiphora Kieffer, 1892 (Diptera: Cecidomyiidae), con tres especies en la Península Ibérica, está caracterizado principalmente por la formación de agallas en las especies de cerrajas (Sonchus spp.); sin embargo, poco se sabe acerca de su distribución actual en Iberia. Además, como valor añadido, varias de las especies que pertenecen a este género son utilizadas como agentes de lucha de control biológico contra las cerrajas invasoras en las regiones del Neártico y de Australasia. Cystiphora sonchi (Vallot, 1827) es una especie paleártica cuya presencia en la Península Ibérica estaba restringida hasta hoy a cuatro citas en el Este de la Península y en las Islas Baleares. Se encontraron tres nuevas poblaciones de esta especie en Coimbra (Portugal centro), añadiendo una nueva especie a la fauna portuguesa. Además, con el objetivo de completar lo máximo posible su distribución, se realizó una búsqueda sistemática en diferentes bases de datos de biodiversidad. Con esos dos enfoques, se estableció un nuevo límite occidental del área de distribución de C. sonchi y se expandió su área de distribución actual en la Península Ibérica con cinco nuevos registros (tres para Portugal, uno para Galicia y uno para Andalucía)
Extreme wave events in the southeastern Iberia coast: Blocks and megablocks as an indicator of tsunamis or extreme storms
Whilst the SW coast of the Iberian Peninsula has a significant record of extreme wave events (EWE), mostly associated with tsunamis, the Mediterranean coast offers a smaller record of these events, although some historical tsunamis with limited impact have been cited on the coast. In general, these studies have been based on the geological record of detrital sequences of sands and silts. In this case, we have focused on the study of coastal deposits of blocks and megablocks in Cope, Murcia (SE of Iberian Peninsula). Here, blocks greater than 1 m and located up to 4 masl were generated by an EWE associated to either a tsunamis or great storm. An unmanned aerial vehicle (drone) has been utilized to perform aerial photogrammetry, which complemented terrestrial photogrammetry of higher resolution.This has been processed to develop a 3D model of the terrain and obtain the dimensional and spatial parameters of these blocks. Different models have been used to calculate potential tsunami wave heights and scale of storms capable of generating such deposits (Nott, 2003; Engel and May, 2012). The results confirm the process of generating force required to generate the block ridges at this site
Novel tools and best practices for education about invasive alien species
Increasing public awareness is a prerequisite for successful management of invasive alien species (IAS). Environmental education can play an important role in this process by providing relevant learning outcomes and experiences for youth and students, as well as professionals in different sectors associated with introduction pathways or who are involved in mitigation and eradication of IAS. This paper responds to the urgent call for the inclusion of the IAS topic in education through the development, implementation and evaluation of novel and user-friendly educational materials. The aim of this paper is to describe best practices in IAS education and to share the lessons learned from eight educational projects from seven different countries. We discuss four challenges for IAS education, related to (1) inconsistent and ambiguous terminology, (2) communicating risk, (3) implementation of education materials, and (4) evaluation of learning effects. Examples of best practices are the use of smartphone applications and gaming elements, place-based education and exhibitions. We also note the importance of open access publishing of education materials to make them easily available. We intend this discussion to serve as a source of inspiration to researchers, science communicators and teachers and to spur the development of new teaching materials worldwide.Peer reviewe
Development of CNC prototype for the characterization of the nanoparticle release during physical manipulation of nanocomposites
This work focuses on the release of nanoparticles from commercially used nanocomposites during machining operations. A reliable and repeatable method was developed to assess the intentionally exposure to nanoparticles, in particular during drilling. This article presents the description and validation of results obtained from a new prototype used for the measurement and monitoring of nanoparticles in a controlled environment. This methodology was compared with the methodologies applied in other studies. Also, some preliminary experiments on drilling nanocomposites are included. Size, shape and chemical composition of the released nanoparticles were investigated in order to understand their hazard potential. No significant differences were found in the amount of nanoparticles released between samples with and without nanoadditives. Also, no chemical alteration was observed between the dust generated and the bulk material. Finally, further developments of the prototype are proposed
Progress in environmental-friendly polymer nanocomposite material from PLA: synthesis, processing and applications
The disposal of large amounts of waste from daily use polymers is among one of the foremost concerns in the current era. Effective utilization of bio-renewable materials procured from natural sources has been proposed as a potential solution to this problem. Among such different polymers, Poly lactic acid (PLA) which is a bio-degradable polymer, resembles quite promotable features, which can be polymerized from sustainable sources as chips sugarcane, starch and corn. Ring-opening polymerization (ROP) of Lactide (LA) monomer considering catalysts such as Al, Sn or Zn is one of the efficient methods for the PLA synthesis. However, the PLA polymerized through this type of catalysts may contain trace elements of the catalyst. Due to their carcinogenic nature, the traces of such catalysts should be (ideally) removed from the synthesis process. The use of alternative energy (AE- UV, Microwave) sources could be a potential route.
Alternative development of non-metal catalysts is best alternatives for the processing of PLA through ROP. PLA layer based composite materials are gaining huge interest due to their multiple application (food, medical etc.) as eco-friendly material. In this article, we review on the implementation of AE sources for PLA processing and to populate the current state-of-the-art associated with the PLA research, especially application in nanocomposite materials field
Comfort constraints evaluation in predictive controller for energy efficiency
[EN] This work reflects the results obtained, through simulation, from the study of the comfort constraints of a Model Predictive Controller (MPC), for the energy management of the centralized air conditioning system of a hotel installation. In order to achieve economic efficiency, the proposed controller is based on a prediction model of the behaviour of the energy consumption of the rooms from the hotel historical records. To satisfy the thermal comfort required by the occupants, a more complete comfort zone model is considered than the one used by (Acosta et al., 2016), in one of the constraints of the optimization problem. This allowed greater energy savings, this being the main contribution of this research. The simulations of the presented scenarios were performed with MATLAB®.[ES] En este trabajo se reflejan los resultados obtenidos, vía simulación, del estudio de las restricciones de confort de un controlador predictivo basado en modelo (MPC) no lineal, para la gestión energética del sistema centralizado de climatización de una instalación hotelera. Con el objetivo de lograr eficiencia económica, el controlador empleado utiliza un modelo de predicción del comportamiento del consumo energético de las habitaciones a partir de los registros históricos del hotel. Para satisfacer el confort térmico requerido por los ocupantes, se considera un modelo de zona de confort más completo, que el modelo utilizado por (Acosta et al., 2016), en una de las restricciones del problema de optimización. Esto permitió un mayor ahorro energético, siendo esta la principal contribución de esta investigación. Las simulaciones de los escenarios presentados fueron realizadas con MATLAB®.Este trabajo ha sido realizado gracias al apoyo del personal de la instalación hotelera que facilitó tanto las mediciones en las habitaciones como los registros históricos de consumo energético.
El cuarto autor agradece el apoyo del Ministerio de Ciencia, Innovación y Universidades/FEDER a través del proyecto PGC2018-099312-B-C31; asimismo el apoyo de la Junta de Castilla y León y EU-FEDER (CLU 2017-09).Marchante, G.; Acosta, A.; González, A.; Zamarreño, J.; Álvarez, V. (2021). Evaluación de restricciones de confort en controlador predictivo para la eficiencia energética. Revista Iberoamericana de Automática e Informática industrial. 18(2):150-163. https://doi.org/10.4995/riai.2020.13937OJS150163182Acosta C. A., González A. I., Zamarreño J.M. and Castelló V., 2008. "A model for energy predictions of a hotel room" 20th European Modeling & Simulation Symposium, (Simulation in Industry). EMSS 2008. Briatico, Italy.Acosta C. A., González A. I., Zamarreño J.M. and Castelló V., 2011. "Modelo para la predicción energética de una instalación hotelera". Revista Iberoamericana de Automática e Informática 8, 309-322. https://doi.org/10.1016/j.riai.2011.09.001Acosta C. A., 2015. "Control Predictivo No Lineal aplicado a la Gestión Energética del Sistema de Climatización Centralizada de las habitaciones de un Inmueble Hotelero", Tesis Doctoral. Instituto Superior Politécnico José Antonio Echeverría, Cuba.Acosta C. A., González A. I., Zamarreño J.M. and Castelló V., 2015. "Controlador Predictivo No Lineal para la Gestión Energética del Sistema Centralizado de Aire Acondicionado de un Inmueble Hotelero". Revista Iberoamericana de Automática e Informática 12, 376-384. https://doi.org/10.1016/j.riai.2015.07.003Acosta C. A., González A. I., Zamarreño J.M. and Castelló V., 2016. "Energy savings and guaranteed thermal comfort in hotel rooms through nonlinear model predictive controllers". Energy and Buildings 129, 59-68. https://doi.org/10.1016/j.enbuild.2016.07.061ASHRAE, 2017. ASHRAE Handbook. Chapter 9, "Thermal Comfort". ASHRAE Handbook Editor.Atthajariyakul S., Leephakpreeda T., 2005. "Neural computing thermal comfort index for HVAC systems". Energy Conversion and Management 46 (15-16), 2553-2565. https://doi.org/10.1016/j.enconman.2004.12.007Auliciems A., Szokolay S. V., 2007. "Thermal Comfort". 2nd ed, Passive and Low Energy Architecture International in association (PLEA), Queensland, 66p.Bogdan M., Walther E., 2017. "Comfort modelling in semi-outdoor spaces". REHVA 54 (1), 23-25. Sitio web: www.rehva.eu.Caballero J. A. y Grossmann I. E., 2007. "Una revisión del estado del arte en optimización". Revista Iberoamericana de Automática e Informática. http://www.revista-riai.org. España, vol. 4, No. 1, pp. 5-23. ISSN: 1697-7912. https://doi.org/10.1016/S1697-7912(07)70188-7Camacho, E.F., Bordons C., 2004. Model Predictive Control, Second edition. Springer-Verlag.Castilla M., Álvarez J.D., Berenguel M., Pérez M., Rodríguez F. and Guzmán J.L., 2010. "Técnicas de control de confort en edificios". Revista Iberoamericana de Automática e Informática 7, 5-24. https://doi.org/10.1016/S1697-7912(10)70038-8Castilla M., Álvarez J.D., Normey-Rico J.E. and Rodríguez F., 2012. "A nonlinear model based predictive control strategy to maintain thermal comfort inside a bioclimatic building". 20th Mediterranean Conference on Control & Automation (MED). Barcelona. Spain, July 3-6. https://doi.org/10.1109/MED.2012.6265714Chávez F.J. ,2002. "Zona Variable de Confort Térmico", Tesis Doctoral, Universidad Politécnica de Cataluña, Barcelona. Sitio web: https://www.tesisenred.net.Da Silva C. F., Freire R. Z. and Mendes N., 2018. "Optimization Applied to Energy Efficiency and Thermal Comfort of Buildings: Bibliometric Analysis on Techniques and Applications". Thermal Engineering 17 (2), 20-27. https://doi.org/10.5380/reterm.v17i2.64126Deb CH., Alur R., 2010. "The significance of Physiological Equivalent Temperature (PET) in outdoor thermal comfort studies". International Journal of Engineering Science and Technology 2(7), 2825-2828.Díaz J., Vuelvas J., Ruiz F., Patiño D., 2019. "A Set-Membership approach to short-term electric load forecasting". Revista Iberoamericana de Automática e Informática Industrial, 16(4):467-479. https://doi.org/10.4995/riai.2019.9819Florez F., Fernández P., Higón J.L., Olivar G. and Taborda J., 2019. "Modeling, Simulation, and Temperature Control of a Thermal Zone with Sliding Modes Strategy". Mathematics 7 (503), 1-13. https://doi.org/10.3390/math7060503Hao H. and Lei C., 2013. "Multi-zone temperature prediction in a commercial building using artificial neural network model". 10th IEEE International Conference on Control and Automation (ICCA) Hangzhou, China, June 12-14.ISO 7730, 2005. "Ergonomics of the thermal environment- Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria". INTERNATIONAL STANDARD. Sitio web: www.iso.org.Joodaki H., Tahmasbizadeh H., 2018. "The Impact of Climate on Ecological Design of Semnan City in Iran". Open Journal of Ecology 8, 1-14. https://doi.org/10.4236/oje.2018.81001Keblawi, A., Ghaddar N., Ghali K., 2011. "Model-based optimal supervisory control of chilled ceiling displacement ventilation system". Energy and Buildings 43, 1359-1370. https://doi.org/10.1016/j.enbuild.2011.01.021Kotsopoulos S. D., Casalegno F., Cuenin A., 2013. "Personalizing Thermal Comfort in a Prototype Indoor Space". SIMUL: The Fifth International Conference on Advances in System Simulation, 178-186.Lingua C., Becchio C., Bottero M. C., Corgnati S. P., Dell Anna F. and Fabi V., 2019. "Energy and Economic Evaluation of Thermal Comfort. The Case Study of the Hotel Residence L'Orologio". 16th IBPSA International Conference and Exhibition; Roma; Italy, 2507-2514. https://doi.org/10.26868/25222708.2019.210687Ma J., Qin J., Salsbury T. and Xu P., 2012. "Demand reduction in building energy systems based on economic model predictive control". Chemical Engineering Science 67, 92-100. https://doi.org/10.1016/j.ces.2011.07.052MathWorks, 2013. MATLAB® 8.1.0.604 (R2013a). Ayuda de la herramienta de simulación.Menyhárt J., Kalmár F., 2019. "Investigation of Thermal Comfort Responses with Fuzzy Logic". Energies 12(1792), 1-13. https://doi.org/10.3390/en12091792NC: 220-3, 2009. "Edificaciones-Requisitos de diseño para la eficiencia energética-Parte 3: Sistemas y equipamiento de calefacción, ventilación, y aire acondicionado". Oficina Nacional de Normalización (NC). Sitio web: www.nc.cubaindustria.cu. 2009.Nishi Y., Gagge A. P., 1977. "Effective Temperature Scale Useful for Hypo- and Hyperbaric Environments". Aviation Space and Enviromental Medicine 48(2), 97-107.Olgyay, V., 1998. "Arquitectura y Clima. Manual de Diseño Bioclimático para Arquitectos y Urbanistas". Ed. Gustavo Gili SL, Barcelona, 216 p. ISBN: 978-84-252-1488-2.Ramírez, P., Gregori, E., Comas, S., Castejón E. and Bartolomé E., 1999. "Ergonomía 2, Confort y Estrés Térmico". Tercera Edición, Ediciones UPC, Barcelona, ISBN: 84-8301-318-5. Sitio web: www.edicionsupc.es.Reza M., Bagherzadeh A., Tavousi T., 2013. Assessment of bioclimatic comfort conditions based on Physiologically Equivalent Temperature (PET) using the Raman Model in Iran. Central European Journal of Geosciences 5(1), 53-60. https://doi.org/10.2478/s13533-012-0118-7Rijal H., Humphreys M. A., Nicol J. F., 2016. "Towards an adaptive model for thermal comfort in Japanese offices" 9th Windsor Conference: Making Comfort Relevant, Windsor, UK, 228-242.Rubin A., 1982. "Thermal Comfort in Passive Solar Buildings -- An Annotated Bibliography". NATIONAL BUREAU OF STANDARDS, Washington. Sitio web: https://www.govinfo.gov/app. https://doi.org/10.6028/NBS.IR.82-2585Sabri M., Ahmad S., Hagishima A., Sukri M., 2015. "Thermal comfort and occupant adaptive behaviour in university offices with cooling and free running modes". International Joint Conference SENVAR-INTA-AVAN 2015, Johor; Malasia, 43-52.Salsbury T., Mhaskar P. and Qin S., 2013. "Predictive Control Methods to Improve Energy Efficiency and Reduce Demand in Buildings", Comp. & Chem. Eng. 51, 77-85. https://doi.org/10.1016/j.compchemeng.2012.08.003Tiwari R., Pandey M., Sharma A., 2010. "An Approach to Human Adaptability towards its Built Environment: A Review". Energy and Power Engineering 2, 90-94. https://doi.org/10.4236/epe.2010.22013Valdivia Y., Álvarez M., Gómez J., Hens L. and Vandecasteele C., 2019. "Sanitary hot water production from heat recovery in hotel buildings in Cuba". Ingeniería Energética 40 (3), 234-244. Sitio web: http://rie.cujae.edu.cu/index.php/RIEVega B.G., Bombino O., Cigler J., Oldewurtel F., Rodríguez M. Á., 2013. "Model Predictive Control for a Tropical Island Hotel". Paper ID 975. CLIMA 2013: 11th REHVA World Congress & 8th International Conference on IAQVEC. Czech Republic.Zhai D. 2019. "Modeling and optimization of ACMV Systems for Energy Efficient Smart Buildings". Tesis Doctoral, Nanyang Technological University, School of Electrical and Electronic Engineering, Singapore
Alien plant species: environmental risks in agricultural and agro-forest landscapes under climate change
Alien plant species have been essential for farming and agro-forestry
systems and for their supply of food, fiber, tannins, resins or wood from antiquity to
the present. They also contributed to supporting functions and regulating services
(water, soil, biodiversity) and to the design of landscapes with high cultural and
scenic value. Some of those species were intentionally introduced, others arrived
accidentally, and a small proportion escaped, naturalized and became invasive in
natural ecosystems—these are known as invasive alien species (IAS). Here, invasive
means that these species have some significant negative impact, either by
spreading from human-controlled environments (e.g. fields, gardens) to natural
ecosystems, where they can cause problems to native species, or to other production
systems or urban areas, impacting on agricultural, forestry activities or human health. Socio-environmental impacts associated with plant invasions have been
increasingly recognized worldwide and are expected to increase considerably under
changing climate or land use. Early detection tools are key to anticipate IAS and to
prevent and control their impacts. In this chapter, we focus on crop and non-crop
alien plant species for which there is evidence or prediction of invasive behaviour
and impacts. We provide insights on their history, patterns, risks, early detection,
forecasting and management under climate change. Specifically, we start by providing
a general overview on the history of alien plant species in agricultural and
agroforestry systems worldwide. Then, we assess patterns, risks and
impacts resulting from alien plants originally cultivated and that became invasive
outside cultivation areas. Afterwards, we provide several considerations
for managing the spread of invasive plant species in the landscape. Finally,
we discuss challenges of alien plant invasions for agricultural and agroforest systems,
in the light of climate change.Joana R. Vicente was supported by POPH/FSE and FCT (Post-Doc grant
SFRH/BPD/84044/2012). Ana Sofia Vaz was supported by FSE/MEC and FCT (Ph.D. grant PD/
BD/52600/2014). Ana Isabel Queiroz supported by FCT—the Portuguese Foundation for Science
and Technology [UID/HIS/04209/2013 and IF/00222/2013/CP1166/CT0001]. This work received
financial support from the European Union (FEDER funds POCI-01-0145-FEDER-006821) and
National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministério da Educação e
Ciência) under the Partnership Agreement PT2020 UID/BIA/50027/201
Numerical investigation and fluid-structure interaction (FSI) analysis on a double-element simplified Formula One (F1) composite wing in the presence of ground effect
This research paper focuses on a novel coupling of the aerodynamic and structural behaviour of a double-element composite front wing of a Formula One (F1) vehicle, which was simulated and studied for the first time here. To achieve this goal, a modified two-way coupling method was employed in the context of high performance computing (HPC) to simulate a steady-state fluid-structure interaction (FSI) configuration using the ANSYS software package. The front wing plays a key role in generating aerodynamic forces and controlling the fresh airflow to maximise the aerodynamic performance of an F1 car. Therefore, the composite front wing becomes deflected under aerodynamic loading conditions due to its elastic behaviour which can lead to changes in the flow field and the aerodynamic performance of the wing. To reduce the uncertainty of the simulations, a grid sensitivity study and the assessment of different engineering turbulence models were carried out. The practical contribution of our investigations is the quantification of the coupled effect of the aerodynamic and structural performance of the wing and an understanding of the influence of ride heights on the ground effect. It was found that the obtained numerical surface pressure distributions, the aerodynamic forces, and the wake profiles show an accurate agreement with experimental data taken from the literature
High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles
APOGEE has amassed the largest ever collection of multi-epoch,
high-resolution (R~22,500), H-band spectra for B-type emission line (Be) stars.
The 128/238 APOGEE Be stars for which emission had never previously been
reported serve to increase the total number of known Be stars by ~6%. We focus
on identification of the H-band lines and analysis of the emission peak
velocity separations (v_p) and emission peak intensity ratios (V/R) of the
usually double-peaked H I and non-hydrogen emission lines. H I Br11 emission is
found to preferentially form in the circumstellar disks at an average distance
of ~2.2 stellar radii. Increasing v_p toward the weaker Br12--Br20 lines
suggests these lines are formed interior to Br11. By contrast, the observed IR
Fe II emission lines present evidence of having significantly larger formation
radii; distinctive phase lags between IR Fe II and H I Brackett emission lines
further supports that these species arise from different radii in Be disks.
Several emission lines have been identified for the first time including
~16895, a prominent feature in the spectra for almost a fifth of the sample
and, as inferred from relatively large v_p compared to the Br11-Br20, a tracer
of the inner regions of Be disks. Unlike the typical metallic lines observed
for Be stars in the optical, the H-band metallic lines, such as Fe II 16878,
never exhibit any evidence of shell absorption, even when the H I lines are
clearly shell-dominated. The first known example of a quasi-triple-peaked Br11
line profile is reported for HD 253659, one of several stars exhibiting intra-
and/or extra-species V/R and radial velocity variation within individual
spectra. Br11 profiles are presented for all discussed stars, as are full
APOGEE spectra for a portion of the sample.Comment: accepted in A
The Open Cluster Chemical Analysis and Mapping Survey: Local Galactic Metallicity Gradient with APOGEE using SDSS DR10
The Open Cluster Chemical Analysis and Mapping (OCCAM) Survey aims to produce
a comprehensive, uniform, infrared-based dataset for hundreds of open clusters,
and constrain key Galactic dynamical and chemical parameters from this sample.
This first contribution from the OCCAM survey presents analysis of 141 members
stars in 28 open clusters with high-resolution metallicities derived from a
large uniform sample collected as part of the SDSS-III/Apache Point Observatory
Galactic Evolution Experiment (APOGEE). This sample includes the first
high-resolution metallicity measurements for 22 open clusters. With this
largest ever uniformly observed sample of open cluster stars we investigate the
Galactic disk gradients of both [M/H] and [alpha/M]. We find basically no
gradient across this range in [alpha/M], but [M/H] does show a gradient for
R_{GC} < 10 kpc and a significant flattening beyond R_{GC} = 10 kpc. In
particular, whereas fitting a single linear trend yields an [M/H] gradient of
-0.09 +/- 0.03$ dex/kpc --- similar to previously measure gradients inside 13
kpc --- by independently fitting inside and outside 10 kpc separately we find a
significantly steeper gradient near the Sun (7.9 <= R_{GC} <= 10) than
previously found (-0.20 +/- 0.08 dex/kpc) and a nearly flat trend beyond 10 kpc
(-0.02 +/- 0.09 dex/kpc).Comment: 6 pages, 4 figures, ApJ letters, in pres
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