1,191 research outputs found
Modeling dust emission in PN IC 418
We investigated the infrared (IR) dust emission from PN IC 418, using a
detailed model controlled by a previous determination of the stellar properties
and the characteristics of the photoionized nebula, keeping as free parameters
the dust types, amounts and distributions relative to the distance of the
central star. The model includes the ionized region and the neutral region
beyond the recombination front (Photodissociation region, or PDR), where the
[OI] and [CII] IR lines are formed. We succeeded in reproducing the observed
infrared emission from 2 to 200~\mm. The global energy budget is fitted by
summing up contributions from big grains of amorphous carbon located in the
neutral region and small graphite grains located in the ionized region (closer
to the central star).
Two emission features seen at 11.5 and 30~\mm are also reproduced by assuming
them to be due to silicon carbide (SiC) and magnesium and iron sulfides
(MgFeS), respectively. For this, we needed to consider ellipsoidal
shapes for the grains to reproduce the wavelength distribution of the features.
Some elements are depleted in the gaseous phase: Mg, Si, and S have sub-solar
abundances (-0.5 dex below solar by mass), while the abundance of C+N+O+Ne by
mass is close to solar. Adding the abundances of the elements present in the
dusty and gaseous forms leads to values closer to but not higher than solar,
confirming that the identification of the feature carriers is plausible. Iron
is strongly depleted (3 dex below solar) and the small amount present in dust
in our model is far from being enough to recover the solar value. A remaining
feature is found as a residue of the fitting process, between 12 and 25~\mm,
for which we do not have identification.Comment: Accepted for publication in Astronomy & Astrophysics. V2: adding
reference
Development of the trajectory planner and control system of a spherical robot manipulator embedded in a FPGA board
Best poster presentation Award3rd Doctoral Congress in Engineering will be held at FEUP on the 27th to 28th of June, 2019This work describes the development and implementation of a linear trajectory controller in a five
degree of freedom (DOF) robot manipulator (Filho and Quintero 2013). An open loop control
architecture was designed and embedded in a Field Programable Gate Array (FPGA), for the first threeDOF. In this paper, we present the direct and inverse kinematics and the Jacobian of the manipulator,
used to extract the control equations of the system (Motta, Llanos-Quintero, and Coral Sampaio 2016).
This model aims the trajectory planning in a rectilinear path, described in Cartesian Coordinates. For
the control implementation embedded in the FPGA, was used the NIOS II microprocessor. This one is
responsible for the path planning and for the speed control of the manipulator joints, with some
accelerated functions in hardware. The validation of the equations and path planning were done using
software simulation. The final structure and experiments of the manipulator are also presented.info:eu-repo/semantics/publishedVersio
Estudio de la trabeculación ósea en la artrodesis subastragalina
En este artÃculo presentamos nuestra casuÃstica en artrodesis artroscópica subastragalina revisando los principios biomecánicos que rigen esta articulación y presentando ésta como una técnica válida para el tratamiento de distintas patologÃas en el retropié que interesan esta articulación.We present our casuistic on arthroscopic subtalar arthrodesis reviewing the biomechanics of this joint and presenting it as a valid technique for the treatment of some pathologies in the rearfoot that affect this joint.Premio al mejor trabajo en el XXXII Congreso de la Sociedad Ibérica de Biomecánica y BiomaterialesPeer ReviewedAward-winnin
Burdigalian deposits of the Santa Cruz Formation in the Sierra Baguales, Austral (Magallanes) Basin: Age, depositional environment and vertebrate fossils
Indexación: Web of Science; Scielo.ABSTRACT. A succession of marine and continental strata on the southern flank of Cerro Cono in the Sierra Baguales,
northeast of Torres del Paine, can be correlated with stratigraphic units exposed along the southern border of the Lago
Argentino region in Santa Cruz Province, Argentina. These include the Estancia 25 de Mayo Formation and the basal
part of the Santa Cruz Formation. The lithological correlation is also confirmed by detrital zircon ages (maximum age
of 18.23±0.26 Ma) and a rich assemblage of terrestrial vertebrate fossils, biostratigraphically equivalent to a postColhuehuapian,
pre-Santacrucian South American Land Mammal Age (SALMA) fauna, suggesting a range of 19 to
17.8 Ma. Similar ages have been obtained from the basal part of the Santa Cruz Formation at Estancia Quién Sabe
in southwestern Argentina, supporting the assumption of a regional continuity between these deposits. A measured
lithostratigraphic column is presented and the depositional environment is interpreted as a coastal plain with small,
meandering rivers and ephemeral floodplain lakes. The sedimentation coincides with intensified uplift of the Patagonian
Andes during the ‘Quechua Phase’ of Andean tectonism, which is reflected by a change in paleocurrent directions from
northwest to east-northeast.
Keywords: Burdigalian, Santa Cruz Formation, Santacrucian SALMA, ‘Notohippidian’ fauna, Meandering rivers.RESUMEN. Una sucesión de estratos marinos y continentales en el flanco meridional del cerro Cono, en la sierra Baguales, al noreste de Torres del Paine, se correlaciona con estratos al sur de la región de lago Argentino en la Provincia de Santa Cruz, República Argentina. Estas unidades incluyen la Formación Estancia 25 de Mayo y la parte basal de la Formación Santa Cruz. La correlación litológica es, además, confirmada por datación de circones detrÃticos (edad máxima de 18,23±0,26 Ma) y un variado ensamble de vertebrados fósiles terrestres de edad post-Colhuehuapense a pre-Santacrucense en la escala de Edades MamÃfero Sudamericanas (EMAS), con un rango temporal de entre 19 a 17,8 Ma. Edades similares han sido reportadas para la parte basal de la Formación Santa Cruz, en estancia Quién Sabe, en el suroeste de Argentina, ratificando la continuidad regional entre estos depósitos. Se presenta una columna estratigráfica y se interpreta el ambiente de depositación como una llanura costera con pequeños rÃos sinuosos y lagos efÃmeros. La edad de sedimentación coincide con el solevantamiento de los Andes Patagónicos durante la 'Fase Quechua', lo que se ve reflejado por un cambio en la dirección de las paleocorrientes desde el noroeste hacia el este-noreste.http://ref.scielo.org/csxwd
Opening the black box of big data sustainable value creation: the mediating role of supply chain management capabilities and circular economy practices
Purpose – This article examines the mechanisms through which big data analytics capabilities (BDAC)
contribute to creating sustainable value and analyzes the mediating roles that supply chain management
capabilities (SCMC), as well as circular economy practices (CEP), play through their impact on sustainable
performance.
Design/methodology/approach – Following a literature review, a serial mediation model is presented.
Hypotheses regarding direct and mediating relationships are tested to determine their potential for
sustainability impact and circularity. Partial least squares structural equation modeling (PLS-SEM) has been
applied for causal and predictive purposes.
Findings – The results indicate that big data analytics capabilities do not have a direct positive impact on
sustainable performance but influence indirectly through SCMC and CEP.
Originality/value – Although some authors have addressed the associations between IT business value,
supply chain (SC), and sustainability, this paper provides empirical evidence related to these relationships.
Additionally, this study performs novel predictive analyses.Junta de AndalucÃa US-126445
Exploration of Power-Performance Tradeoffs through Parameterization of FPGA-based Multiprocessor Systems
The design space of FPGA-based processor systems is huge, because many parameters can be modified at design- and runtime to achieve an efficient system solution in terms of performance, power and energy consumption. Such parameters are, for example, the number of processors and their configurations, the clock frequencies at design time, the use of dynamic frequency scaling at runtime, the application task distribution, and the FPGA type and size. The major contribution of this paper is the exploration of all these parameters and their impact on performance, power dissipation, and energy consumption for four different application scenarios. The goal is to introduce a first approach for a developer’s guideline, supporting the choice of an optimized and specific system parameterization for a target application on FPGA-based multiprocessor systems-on-chip. The FPGAs used for these explorations were Xilinx Virtex-4 and Xilinx Virtex-5. The performance results were measured on the FPGA while the power consumption was estimated using the Xilinx XPower Analyzer tool. Finally, a novel runtime adaptive multiprocessor architecture for dynamic clock frequency scaling is introduced and used for the performance, power and energy consumption evaluations
Análisis de las representaciones acerca de la economÃa en jóvenes universitarios del Caribe Colombiano
ResumenLa investigación indagó acerca de la construcción de conceptoseconómicos en una muestra de 50 estudiantes universitarios, residentesen una ciudad multifinanciera de la región Caribe colombiana.Para conocer las conceptualizaciones se aplicó una entrevistaen profundidad que permitió indagar sobre la función, valor ycirculación del dinero y la emisión y acuñación monetaria. Se encontróque sólo el 24% de los jóvenes universitarios alcanza elnivel de pensamiento económico inferencial, y no hay diferenciassignificativas de acuerdo con el programa académico al que pertenecen.Los resultados indican que los jóvenes presentan un desfaseen cuanto a nivel de pensamiento económico, de acuerdo con elcontexto internacional.AbstractThis research was about find out the construction of the economicconcepts in a sample of 50 university students, residents in a multifinancialcity of Caribbean Colombian Region. To get to know the conceptualizationwe applied a deep interwiev and we could investigate about the function,value and circulation of money and the emission and circulation of themoney. We found that just the 24% of the young students reach the levelof the economic inferential thought, and there not significant differencesin agreement with the academic program to that they belong. The resultsindicate that although the young people present a difference as far as thelevel of the economic thought with the international context
Control of mucocutaneous leishmaniasis, a neglected disease: results of a control programme in Satipo Province, Peru.
Mucocutaneous leishmaniasis (MCL) is an important health problem in many rural areas of Latin America, but there are few data on the results of programmatic approaches to control the disease. We report the results of a control programme in San Martin de Pangoa District, which reports one of the highest prevalences of MCL in Peru. For 2 years (2001--2002), the technicians at the health post were trained in patient case management, received medical support and were supplied with antimonials. An evaluation after 2 years showed the following main achievements: better diagnosis of patients, who were confirmed by microscopy in 34% (82/240) of the cases in 2001 and 60% of the cases (153/254) in 2002; improved follow-up during treatment: 237 of 263 (90%) patients who initiated an antimonial therapy ended the full treatment course; improved follow-up after treatment: 143 of 237 (60%) patients who ended their full treatment were correctly monitored during the required period of 6 (cutaneous cases) or 12 (mucosal cases) months after the end of treatment. These achievements were largely due to the human and logistical resources made available, the constant availability of medications and the close collaboration between the Ministry of Health, a national research institute and an international non-governmental organization. At the end of this period, the health authorities decided to register a generic brand of sodium stibogluconate, which is now in use. This should allow the treatment of a significant number of additional patients, while saving money to invest in other facets of the case management
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