Body Control Module using the SAM-V71 development board

The Body Control Module is one of the main devices inside a car since it is responsible of the critical aspects for the correct function of the vehicle including the safety and comfort of all passengers. However, these features come at a high cost. Therefore, the aim of this project was to perform a BCM capable of executing the basic functions of a commercial module in a car but with a lower cost. This was achieved using the SAMV71 development board and its embedded CAN protocol communication port and following the V-cycle which has two main branches: planning and integration of their parts and validation. This model facilitates keeping track of any progress during the development stage. The device successfully read analog and digital inputs, processed the information and sent it through the CAN bus for further processing. AUTOSAR was the standard used trough the development process, since it is the most employed in the automotive industry. It specifies that the software components shall be in layers, helping the process of integration and giving portability to the project. With this BCM it is possible to adapt a classic internal combustion engine car that lacks modern electronics to a battery electric vehicle

Morpho-kinematic analysis of the point-symmetric, bipolar planetary nebulae Hb 5 and K 3-17, a pathway to poly-polarity

The kinematics of the bipolar planetary nebulae Hb~5 and K 3-17 are investigated in detail by means of a comprehensive set of spatially resolved high spectral resolution, long-slit spectra. Both objects share particularly interesting characteristics, such as a complex filamentary, rosette-type nucleus, axial point-symmetry and very fast bipolar outflows. The kinematic information of Hb~5 is combined with {\it HST} imagery to construct a detailed 3D model of the nebula using the code SHAPE. The model shows that the large scale lobes are growing in a non-homologous way. The filamentary loops in the core are proven to actually be secondary lobes emerging from what appears to be a randomly punctured, dense, gaseous core and the material that forms the point symmetric structure flows within the lobes with a distinct kinematic pattern and its interaction with the lobes has had a shaping effect on them. Hb~5 and K~3-17 may represent a class of fast evolving planetary nebulae that will develop poly-polar characteristics once the nebular core evolves and expands.Comment: 19 pages, 8 figures. To appear in The Astrophysical Journa

Wolf-Rayet and LBV Nebulae as the Result of Variable and Non-Spherical Stellar Winds

The physical basis for interpreting observations of nebular morphology around massive stars in terms of the evolution of the central stars is reviewed, and examples are discussed, including NGC 6888, OMC-1, and eta Carinae.Comment: To be published in the Proceedings of IAU Colloquium 169 on Variable and Non-Spherical Stellar Winds in Luminous Hot Stars, ed. B. Wolf (Springer-Verlag, Berlin, Heidelberg). 7 pages, including 5 figures. A full-resolution version of fig 4 is available in the version at http://www.mpia-hd.mpg.de/theory/preprints.html#maclo

The outflows and 3D structure of NGC 6337, a planetary nebula with a close binary nucleus

NGC 6337 is a member of the rare group of planetary nebulae where a close binary nucleus has been identified. The nebula's morphology and emission line profiles are both unusual, particularly the latter. We present a thorough mapping of spatially resolved, long-slit echelle spectra obtained over the nebula that allows a detailed characterization of its complex kinematics. This information, together with narrow band imagery is used to produce a three dimensional model of the nebula using the code SHAPE. The 3-D model yields a slowly expanding toroid with large density fluctuations in its periphery that are observed as cometary knots. A system of bipolar expanding caps of low ionization are located outside the toroid. In addition, an extended high velocity and tenuous bipolar collimated outflow is found emerging from the core and sharply bending in opposite directions, a behavior that cannot be accounted for by pure magnetic launching and collimation unless the source of the outflow is precessing or rotating, as could be expected from a close binary nucleus.Comment: Accepted for publication in Astrophysical Journa

A magnetically collimated jet from an evolved star

Planetary nebulae often have asymmetric shapes, which could arise due to collimated jets from evolved stars before evolution to the planetary nebula phase. The source of jet collimation in these stars is unknown. Magnetic fields are thought to collimate outflows that are observed in many other astrophysical sources, such as active galactic nuclei and proto-stars, although hitherto there are no direct observations of both the magnetic field direction and strength in any collimated jet. Theoretical models have shown that magnetic fields could also be the dominant source of collimation of jet in evolved stars. Here we report measurements of the polarization of water vapour masers that trace the precessing jet emanating from the asymptotic giant branch star W43A at 2.6 kpc from the Sun, which is undergoing rapid evolution into a planetary nebula. The masers occur in two clusters at opposing tips of the jets, ~1,000 AU from the star. We find direct evidence that the magnetic field is collimating the jet.Comment: Published in Nature 440 (March 2nd 2006). High-res figures can be found at http://www.jb.man.ac.uk/~wouter/papers/w43a/w43a.htm

High-pressure optical absorption in InN: Electron density dependence in the wurtzite phase and reevaluation of the indirect band gap of rocksalt InN

We report on high-pressure optical absorption measurements on InN epilayers with a range of free-electron concentrations (5×1017–1.6×1019 cm−3) to investigate the effect of free carriers on the pressure coefficient of the optical band gap of wurtzite InN. With increasing carrier concentration, we observe a decrease of the absolute value of the optical band gap pressure coefficient of wurtzite InN. An analysis of our data based on the k·p model allows us to obtain a pressure coefficient of 32 meV/GPa for the fundamental band gap of intrinsic wurtzite InN. Optical absorption measurements on a 5.7-μm-thick InN epilayer at pressures above the wurtzite-to-rocksalt transition have allowed us to obtain an accurate determination of the indirect band gap energy of rocksalt InN as a function of pressure. Around the phase transition (∼15 GPa), a band gap value of 0.7 eV and a pressure coefficient of ∼23 meV/GPa are obtained. ©2012 American Physical SocietyThis work was supported by the Spanish Ministry of Science and Innovation through Project No. MAT2010-16116.Ibáñez, J.; Segura, A.; García-Domene, B.; Oliva, R.; Manjón Herrera, FJ.; Yamaguchi, T.; Nanishi, Y.... (2012). High-pressure optical absorption in InN: Electron density dependence in the wurtzite phase and reevaluation of the indirect band gap of rocksalt InN. Physical Review B. 86:35210-1-35210-5. https://doi.org/10.1103/PhysRevB.86.035210S35210-135210-586Wu, J. (2009). When group-III nitrides go infrared: New properties and perspectives. Journal of Applied Physics, 106(1), 011101. doi:10.1063/1.3155798Ueno, M., Yoshida, M., Onodera, A., Shimomura, O., & Takemura, K. (1994). Stability of the wurtzite-type structure under high pressure: GaN and InN. Physical Review B, 49(1), 14-21. doi:10.1103/physrevb.49.14Uehara, S., Masamoto, T., Onodera, A., Ueno, M., Shimomura, O., & Takemura, K. (1997). Equation of state of the rocksalt phase of III–V nitrides to 72 GPa or higher. Journal of Physics and Chemistry of Solids, 58(12), 2093-2099. doi:10.1016/s0022-3697(97)00150-9Pinquier, C., Demangeot, F., Frandon, J., Chervin, J.-C., Polian, A., Couzinet, B., … Maleyre, B. (2006). Raman scattering study of wurtzite and rocksalt InN under high pressure. Physical Review B, 73(11). doi:10.1103/physrevb.73.115211Ibáñez, J., Manjón, F. J., Segura, A., Oliva, R., Cuscó, R., Vilaplana, R., … Artús, L. (2011). High-pressure Raman scattering in wurtzite indium nitride. Applied Physics Letters, 99(1), 011908. doi:10.1063/1.3609327Li, S. X., Wu, J., Haller, E. E., Walukiewicz, W., Shan, W., Lu, H., & Schaff, W. J. (2003). Hydrostatic pressure dependence of the fundamental bandgap of InN and In-rich group III nitride alloys. Applied Physics Letters, 83(24), 4963-4965. doi:10.1063/1.1633681Franssen, G., Gorczyca, I., Suski, T., Kamińska, A., Pereiro, J., Muñoz, E., … Svane, A. (2008). Bowing of the band gap pressure coefficient in InxGa1−xN alloys. Journal of Applied Physics, 103(3), 033514. doi:10.1063/1.2837072Kamińska, A., Franssen, G., Suski, T., Gorczyca, I., Christensen, N. E., Svane, A., … Georgakilas, A. (2007). Role of conduction-band filling in the dependence of InN photoluminescence on hydrostatic pressure. Physical Review B, 76(7). doi:10.1103/physrevb.76.075203Shan, W., Walukiewicz, W., Haller, E. E., Little, B. D., Song, J. J., McCluskey, M. D., … Stall, R. A. (1998). Optical properties of InxGa1−xN alloys grown by metalorganic chemical vapor deposition. Journal of Applied Physics, 84(8), 4452-4458. doi:10.1063/1.368669Millot, M., Geballe, Z. M., Yu, K. M., Walukiewicz, W., & Jeanloz, R. (2012). Red-green luminescence in indium gallium nitride alloys investigated by high pressure optical spectroscopy. Applied Physics Letters, 100(16), 162103. doi:10.1063/1.4704367Franssen, G., Suski, T., Perlin, P., Teisseyre, H., Khachapuridze, A., Dmowski, L. H., … Schaff, W. (2006). Band-to-band character of photoluminescence from InN and In-rich InGaN revealed by hydrostatic pressure studies. Applied Physics Letters, 89(12), 121915. doi:10.1063/1.2356994Ibáñez, J., Segura, A., Manjón, F. J., Artús, L., Yamaguchi, T., & Nanishi, Y. (2010). Electronic structure of wurtzite and rocksalt InN investigated by optical absorption under hydrostatic pressure. Applied Physics Letters, 96(20), 201903. doi:10.1063/1.3431291Cuscó, R., Ibáñez, J., Alarcón-Lladó, E., Artús, L., Yamaguchi, T., & Nanishi, Y. (2009). Raman scattering study of the long-wavelength longitudinal-optical-phonon–plasmon coupled modes in high-mobility InN layers. Physical Review B, 79(15). doi:10.1103/physrevb.79.155210Cuscó, R., Alarcón-Lladó, E., Ibáñez, J., Yamaguchi, T., Nanishi, Y., & Artús, L. (2009). Raman scattering study of background electron density in InN: a hydrodynamical approach to the LO-phonon–plasmon coupled modes. Journal of Physics: Condensed Matter, 21(41), 415801. doi:10.1088/0953-8984/21/41/415801Syassen, K. (2008). Ruby under pressure. High Pressure Research, 28(2), 75-126. doi:10.1080/08957950802235640Wu, J., Walukiewicz, W., Shan, W., Yu, K. M., Ager, J. W., Li, S. X., … Schaff, W. J. (2003). Temperature dependence of the fundamental band gap of InN. Journal of Applied Physics, 94(7), 4457-4460. doi:10.1063/1.1605815Wu, J., Walukiewicz, W., Li, S. X., Armitage, R., Ho, J. C., Weber, E. R., … Jakiela, R. (2004). Effects of electron concentration on the optical absorption edge of InN. Applied Physics Letters, 84(15), 2805-2807. doi:10.1063/1.1704853Wu, J., Walukiewicz, W., Shan, W., Yu, K. M., Ager, J. W., Haller, E. E., … Schaff, W. J. (2002). Effects of the narrow band gap on the properties of InN. Physical Review B, 66(20). doi:10.1103/physrevb.66.201403Rinke, P., Winkelnkemper, M., Qteish, A., Bimberg, D., Neugebauer, J., & Scheffler, M. (2008). Consistent set of band parameters for the group-III nitrides AlN, GaN, and InN. Physical Review B, 77(7). doi:10.1103/physrevb.77.075202Furthmüller, J., Hahn, P. H., Fuchs, F., & Bechstedt, F. (2005). Band structures and optical spectra of InN polymorphs: Influence of quasiparticle and excitonic effects. Physical Review B, 72(20). doi:10.1103/physrevb.72.205106Serrano, J., Rubio, A., Hernández, E., Muñoz, A., & Mujica, A. (2000). Theoretical study of the relative stability of structural phases in group-III nitrides at high pressures. Physical Review B, 62(24), 16612-16623. doi:10.1103/physrevb.62.16612Christensen, N. E., & Gorczyca, I. (1994). Optical and structural properties of III-V nitrides under pressure. Physical Review B, 50(7), 4397-4415. doi:10.1103/physrevb.50.4397Duan, M.-Y., He, L., Xu, M., Xu, M.-Y., Xu, S., & Ostrikov, K. (Ken). (2010). Structural, electronic, and optical properties of wurtzite and rocksalt InN under pressure. Physical Review B, 81(3). doi:10.1103/physrevb.81.03310

The planetary nebula NGC 1360, a test case of magnetic collimation and evolution after the fast wind

The central star of this nebula has an observed intense magnetic field and the fast wind is no longer present, indicating that a back flow process has probably developed. Long-slit, spatially resolved echelle spectra have been obtained across the main body of NGC 1360 and over its system of bipolar jets. Deep images of the knotty structures of the jets have also been obtained. The data allow a detailed study of the structure and kinematics of this object and the results are modeled considering the effects of a magnetic collimation process in the development of the nebula and then switching off the fast stellar wind to follow its evolution to its current state. The model is able to successfully reproduce many of the key features of NGC 1360 under these premises.Comment: 16 pages, 7 figures. ApJ in pres

Influence of gaseous pollutants and their synergistic effects on the aging of reflector materials for concentrating solar thermal technologies

ABSTRACT: Concentrating solar thermal technologies have experienced an important boost in the last few years. Besides the production of electricity, they are particularly useful for the supply of industrial process heat. The industrial atmospheres affecting these solar plants typically contain gaseous pollutants that are likely to promote corrosion on the components of the solar facility, specifically solar reflectors, thereby compromising their optimal performance and the overall system efficiency. Seven accelerated aging tests were designed to study the effects of three air pollutants (H2S, SO2 and NO2) on the durability of two commercially available reflector types (silvered glass and aluminum), both in single-gas tests and in multicomponent gas mixtures. Additionally, the same material types were exposed outdoors at five representative polluted sites, including industrial, urban and coastal environments. Reflectance and optical microscope monitoring corroborated which degree of corrosion was developed on a specific type of reflector in the different tests with gaseous pollutants, as well as the synergistic effects of gas combinations. For example, tests with sulfur were harmful for silvered-glass reflectors (up to a total of 16 corrosion spots), whereas aluminum was particularly affected by tests with NO2 (numerous micro spots of around 50 pm size). Moreover, comparisons of the corrosion patterns found in accelerated-aging and outdoor exposures revealed which laboratory test reproduced the different real polluted atmospheres in the most realistic way, which is the main goal of this work. For instance, the degradation found at Site 2 was reproduced by Test NO2+SO2, with an acceleration factor of 27.info:eu-repo/semantics/publishedVersio

Rotten Egg Nebula: The magnetic field of a binary evolved star

Most of PNe are not spherical. The loss of spherical symmetry occurs somewhere between the AGB and PN phase. The cause of this change of morphology is not yet well known, but magnetic fields are one of the possible agents. Its origin remains to be determined, and potentially requires the presence of a massive companion to the AGB star. Therefore, further detections of the magnetic field around evolved stars (in particular those thought to be part of a binary system) are crucial to improve our understanding of the origin and role of magnetism on evolved stars. One such binaries is the pre-PN OH231.8, around which a magnetic field was detected in the OH maser region of the outer circumstellar envelope. We aim to detect and infer the properties of the magnetic field of this source in the water maser region. We observed the 6_{1,6}-5_{2,3} water maser rotational transition to determine its linear and circular polarization. These emissions are located within the inner regions of OH231.8 (at few tens of AU). We detected 30 water maser features, which occur in two distinct regions that are moving apart with a velocity on the sky of 2.3 mas/year. Taking into account the inclination angle of the source, this corresponds to an average separation velocity of 21 km/s. Based on the velocity gradient of the maser emission, the masers appear to be dragged along the direction of the nebula jet. Linear polarization is present in 3 of the features, and circular polarization was detected in the 2 brightest ones. We found that the strength of the magnetic field is |B_{||}|~45 mG which, when assuming a toroidal magnetic field, implies B~2.5 G on the stellar surface. The morphology of the field is not yet determined, but the high scatter found on the directions of the linear polarization vectors could indicate that the masers occur near the tangent points of a toroidal field.Comment: 7 pages, 4 figure

A Fast bipolar H2 outflow from IRAS 16342-3814: an old star reliving its youth

Some evolved stars in the pre-planetary nebula phase produce highly-collimated molecular outflows that resemble the accretion-driven jets and outflows from pre-main sequence stars. We show that IRAS 16342-3814 (the Water Fountain Nebula) is such an object and present K-band integral field spectroscopy revealing a fast (> 150 km/s) bipolar H2 outflow. The H2 emission is shock excited and may arise in fast-moving clumps, accelerated by the previously observed precessing jet. The total luminosity in H2 is 0.37 L$_{\odot}$ which is comparable with that of accretion-powered outflows from Class 0 protostars. We also detect CO overtone bandhead emission in the scattered continuum, indicating hot molecular gas close to the centre, a feature also observed in a number of protostars with active jets. It seems likely that the jet and outflow in IRAS 16342-3814 are powered by accretion onto a binary companion.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Societ