42 research outputs found
Proton cyclotron wave generation mechanisms upstream of Venus
No full text[1] Long-term observations of proton cyclotron waves in the upstream region of Venus raise the question of under which general solar wind conditions these waves are generated and maintained. The waves are characterized by their occurrence at the local proton cyclotron frequency and left-hand polarization, both in the spacecraft frame. Magnetometer data of the Venus Express spacecraft for two Venus years of observations are analyzed before, during, and after the occurrence of these waves. The configuration of the upstream magnetic field and the solar wind velocity is investigated, to study if the waves are generated from a ring distribution of pickup ions in velocity space or from a parallel pickup ion beam, i.e., for quasi-parallel conditions of solar wind velocity and magnetic field when the solar wind motional electric field is weak. It is found that stable and mainly quasi-parallel magnetic field conditions for up to ∼20 min prior to wave observation are present, enabling sufficient ion pickup and wave growth to obtain observable waves in the magnetometer data. Persistent waves occur mainly under quasi-parallel conditions. This is in agreement with linear theory, which predicts efficient wave growth for instabilities driven by field-aligned planetary ion beams, already for low pickup ion density. The occurrence of highly coherent waves at 4 RV upstream toward the Sun implies that planetary neutral hydrogen is initially picked up at least 5 RV toward the Sun from a sufficiently dense Venus hydrogen exosphere.Fil: Delva, M.. Austrian Academy of Sciences; AustriaFil: Mazelle, C.. Universitá Paul Sabatier; FranciaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Volwerk, M.. Austrian Academy of Sciences; AustriaFil: Vörös, Z.. University of Innsbruck; AustriaFil: Zhang, T. L.. Austrian Academy of Sciences; Austri
Cassini encounters with hot flow anomaly-like phenomena at Saturn's bow shock
No full textThe first observations of the kronian equivalent of hot flow anomalies (HFAs) are presented. Using magnetic field and plasma data we discuss two events that were observed upstream of Saturn's bow shock during the first two orbits of the Cassini spacecraft. We suggest that these events result from the interaction between interplanetary current sheets and the shock surface. This same interaction is responsible for HFAs at the terrestrial bow shock. Calculations of electron temperature reveal an increase by a factor of approximately two for the first event, which is less than for terrestrial HFAs where the increase is by approximately an order of magnitude. In contrast to terrestrial HFAs we find that these events are associated with density enhancement rather than reduction. Estimates of the total pressure for the first event imply that the central region is expanding
Gestão ambiental e sustentabilidade - uma análise das práticas ambientais e da aplicação da ISO 14.001: estudo de caso numa empresa do setor automobilístico
No full textDissertação (mestrado profissional) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Ambiental, Florianópolis, 2012.Esta pesquisa de mestrado teve por objeto de estudo analisar as práticas de gestão ambiental e a aplicação da norma ISO 14001 numa empresa do setor automobilístico da região metropolitana de Belo Horizonte. Como referencial teórico, analisamos a evolução das práticas de gestão ambiental e os requisitos da norma internacional ISO 14001, bem como a importância da sustentabilidade. Esta pesquisa também apresenta neste estudo de caso de todas as etapas de implantação do sistema de gestão ambiental com base na norma ISO 14001.Abstract : This Master thesis was to analyze the object of study environmental management practices and the application of ISO 14001 in a company in the automotive sector in the metropolitan region of Belo Horizonte. As a theoretical framework, we analyze the evolution of environmental management practices and the requirements of international standard ISO 14001 as well as the importance of sustainability. This research also presents this case study of all stages of implementation of the environmental management system based on ISO 14001
Dynamics of Saturn's magnetodisk near Titan's orbit: Comparison of Cassini magnetometer observations from real and virtual Titan flybys
No full textWe analyze the variability of the ambient magnetospheric field along Titan’s orbit at 20.3 Saturn radii. However, while our preceding study (Simon et al., 2010) focused on Cassini magnetometer observations from the 62 Titan flybys (TA–T62) between October 2004 and October 2009, the present work discusses magnetic field data that were collected near Titan’s orbit when the moon was far away. In analogy to
the observations during TA–T62, the magnetospheric fields detected during these 79 ‘‘virtual’’ Titan flybys are strongly affected by the presence of Saturn’s bowl-shaped and highly dynamic magnetodisk current sheet. We therefore provide a systematic classification of the magnetic field observations as magnetodisk current sheet or lobe-type scenarios. Among the 141 (62 real+79 virtual) crossings of
Titan’s orbit between July 2004 and December 2009, only 17 encounters (9 real+8 virtual) took place within quiet, magnetodisk lobe-type fields. During another 50 encounters (21 real+29 virtual), rapid transitions between current sheet and lobe fields were observed around the moon’s orbital plane. Most of the encounters (54¼22 real+32 virtual) occurred when Titan’s orbit was embedded in highly
distorted current sheet fields, thereby invalidating the frequently applied idealized picture of Titan interacting with a homogeneous and stationary magnetospheric background field. The locations of real and virtual Titan flybys are correlated to each other. Each of the 62 real Titan flybys possesses at least one virtual counterpart that occurred shortly before or after the real encounter and at nearly the same orbital position. A systematic comparison between Cassini magnetometer observations from the real Titan flybys and their virtual companions suggests that there is no clear evidence of Titan exerting a significant level of control on the vertical oscillatory motion of the magnetodisk near its orbit.Fil: Simon, Sven. University of Cologne; AlemaniaFil: Wennmacher, Alexandre. University of Cologne; AlemaniaFil: Neubauer, Fritz M.. University of Cologne; AlemaniaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Kriegel, Hendrik. Institute for Theoretical Physics; AlemaniaFil: Russell, Christopher T.. University of California; Estados UnidosFil: Dougherty, Michele K.. Imperial College London; Reino Unid
Structure of Titan ’ s induced magnetosphere under varying background magnetic fi eld conditions: Survey of Cassini magnetometer data from fl ybys TA – T85
No full textCassini magnetic field observations between 2004 and 2012 suggest the ambient field conditions near Titan’s orbit to differ significantly from the frequently applied pre-Cassini picture (background magnetic field homogeneous and perpendicular to Titan’s orbital plane, stationary upstream conditions). In this study, we analyze the impact of these varying background field conditions on the structure of Titan’s induced magnetosphere by conducting a systematic survey of Cassini magnetic field observations in the interaction region during flybys TA–T85 (July 2004–July 2012). We introduce a set of criteria that allow to identify deviations in the structure of Titan’s induced magnetosphere—as seen by the Cassini magnetometer (MAG)—from the picture of steady-state field line draping. These disruptions are classified as “weak”, “moderate”, or “strong”. After applying this classification scheme to all available Titan encounters, we survey the data for a possible correlation between the disruptions of the draping pattern and the ambient magnetospheric field conditions, as characterized by Simon et al. [2010a]. Our major findings are: (1) When Cassini is embedded in the northern or southern lobe of Saturn’s magnetodisk within a ` 3 h interval around closest approach, Titan’s induced magnetosphere shows little or no deviations at all from the steady-state draping picture. (2) Even when Titan is embedded in perturbed current sheet fields during an encounter, the notion of draping the average background field around the moon’s ionosphere is still applicable to explain MAG observations from numerous Titan flybys. (3) Only when Titan is exposed to intense north- south oscillations of Saturn’s current sheet at the time of an encounter, the signatures of the moon’s induced magnetosphere may be completely obscured by the ambient field perturbations. (4) So far, T70 is the only flyby that fully meets the idealized pre-Cassini picture of the Titan interaction (steady background field perpendicular to Titan’s orbital plane, steady upstream flow, unperturbed induced magnetosphere).Fil: Simon, Sven. University of Cologne. Institute of Geophysics and Meteorology; AlemaniaFil: van Treeck, Shari C.. University of Cologne. Institute of Geophysics and Meteorology; AlemaniaFil: Wennmacher, Alexandre. University of Cologne. Institute of Geophysics and Meteorology; AlemaniaFil: Saur, Joachim. University of Cologne. Institute of Geophysics and Meteorology; AlemaniaFil: Neubauer, Fritz M.. University of Cologne. Institute of Geophysics and Meteorology; AlemaniaFil: Bertucci, Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio(i); ArgentinaFil: Dougherty, Michele K.. Imperial College Of Science And Technology. Space and Atmospheric Physics Group; Reino Unid
Competências e Habilidades na ótica dos processos de recrutamento para programas de trainee
No full textTCC (graduação) - Universidade Federal de Santa Catarina, Centro Sócio Econômico, Curso de Administração.O mundo vem mudando numa freqüência cada vez maior, a globalização e tecnologia proporcionaram uma nova forma de administrar, um novo perfil de mercado e de empresas. E, acompanhando estas mudanças na competitividade das empresas surgiu a necessidade de profissionais qualificados, vitais para a prosperidade dos negócios. Se por um lado a tarefa de encontrar e manter talentos na área gerencial é muito difícil, do outro lado para os gerentes conseguirem uma boa colocação envolve muita competitividade, visto que ao referir-se a cargos de gerência nesta pesquisa não se está limitando ao profissional de Administração. Desta forma o grau de dificuldade para o profissional de Administração conseguir estas vagas também é muito grande. O primeiro desafio nesta busca por talentos por parte dos empregadores é determinar as habilidades e competências necessárias para estes profissionais de administração. O presente trabalho teve como objetivo verificar a relação entre as competências e habilidades dos profissionais de administração descritas na literatura com o perfil que as 150 maiores empresas do pais exigem nos processos de recrutamento e seleção atuais para programas de trainee abertos de janeiro a setembro de 2007. Para atingir tal objetivo foram descritos as habilidades e competências necessárias ao profissional de administração de acordo com alguns autores e pesquisas. Posteriormente foram analisadas 26 empresas que abriram recrutamento para programa de trainee em 2007 e descritas as competências necessárias para os candidatos, com o objetivo de tragar um perfil dos trainees e comparar com a teoria utilizada. Constatou-se que os conhecimentos, valores e atitudes e habilidades solicitadas nos programas de trainee pesquisados e na teoria apresentada nesta pesquisa há muitas semelhanças entre ambos, com algumas diferenças que são próprias dos programas de trainee como: público recém-formado e foco no perfil pessoal dos candidatos devido aos treinamentos que receberão para assumir um cargo de gerência. E quanto ao perfil que as maiores empresas do pais está procurando, a partir da análise das competências solicitadas nos programas de trainee pesquisados, chegou-se ao seguinte perfil: jovens talentosos, formados há até dois anos, com bons conhecimentos em inglês e informática, disponibilidade para mudanças de cidade, estado e pais, disponibilidade para viagens, com espirito empreendedor, dinâmicos, pró-ativos, com bom relacionamento interpessoal, que trabalhe bem em equipe e seja focado em resultado
DOES THE CIRCULAR DICHROISM OF CH-STRETCHING OVERTONES HELP ONE TO DISTINGUISH BETWEEN NORMAL MODES AND LOCAL MODES?
No full text S. Abbate, G. Longhi, L. Ricard, C. Bertucci, C. Rosini, P. Salvadori, A. Moscowitz, J. A. C. S. 111., 836 (1989) E. Castiglioni, F. Lebon, G. Longhi, S. Abbate, Enantiomer, 7, 161 (2002) S. Abbate, R. Gangemi, G. Longhi, J. Chem. Phys, 117, 7575 (2002)Author Institution: Dipartimento di Scienze Biomediche e Biotecnologie, Universit\'{e} di BresciaSeveral years ago we presented a number of Vibrational Circular Dichroism (VCD) spectra of natural compounds in the CH-stretching 2nd and 3rd overtone . In that paper we pointed out that normal modes and local modes in chiral molecules can be distinguished by means of VCD spectra. The presence or absence of VCD rotational strengths was accounted for as deriving from mechanical coupling between bond electric dipole moments. Based on recently acquired VCD and on further theoretical , we have found that also local modes can generate VCD spectra of characteristic aspect, due to the interaction of CH-oscillators with polarizable groups. A very short review of our data will be reported and rationalized in the present talk
Forces, electric fields and currents at the subsolar martian MPB: MAVEN observations and multifluid MHD simulation
No full textInternational audienceThe Martian MPB (Magnetic Pileup Boundary) is a key boundary in the Mars/Solar Wind interaction as it is here that part of the momentum and energy from the solar wind plasma are transferred to the planetary plasma. Since this interaction is for the most part collisionless, the transfer is mediated by electric and magnetic fields. The acceleration processes and the interaction of particles with electromagnetic fields operate at spatial scales determined by the ambient particle populations. In particular, in regions with sizes of the order of the ion inertial length (ion scales), the Hall electric field is expected to be dominant. In the present work we combine data from the MAVEN spacecraft along one orbit around Mars and multifluid MHD simulation results to study the role of electric fields, currents and forces at the MPB at ion scales. In particular, we find that the current densities deduced from MAVEN data (J ∼ 238 nA/m2) of the same order as the values obtained in the simulation (J ∼ 56-156 nA/m2) and that the Hall electric force points sunward in both cases. In addition, we find that in the subsolar MPB current layer the Hall electric field (∼3.2 mV/m) dominates over the solar wind convective electric field (∼0.4 mV/m) and electron pressure gradient (∼0.8 mV/m). These values are consistent with previous results suggesting that the MPB thickness is of the order of the solar wind proton inertial length and support the idea that non ideal terms in Ohm's law must be considered when analysing the dynamics of particles around plasma boundaries with ion scale thicknesses
A 'philosophical storehouse': the life and afterlife of the Royal Society's repository
No full textPhDIn June 1781, the Royal Society’s repository was transferred to the British
Museum. Though ostensibly as a result of the limited space in the Royal Society’s
purpose-built accommodation at Somerset House, the Society were perhaps also a
little relieved to relinquish a collection that had proved to be somewhat burdensome
during its residence at the Society and which was frequently criticised for its decaying
specimens, broken items and missing, possibly stolen, objects. However this seems to
be only part of the story. Drawing upon manuscript material in the Royal Society and
the British Library, this study will examine the repository’s pattern of usage,
collecting strategies and intellectual output throughout its life, in addition to exploring
its afterlife at the British Museum using the British Museum’s, Royal College of
Surgeon’s and Natural History Museum’s extensive archives. This thesis will seek to
reveal an alternative account of the Royal Society’s repository arguing that it was
comprised of a substantial and significant collection that the British Museum, at least
initially, appears to have been grateful to receive and which, periodically, played a
central role in the Society’s and naturalists' work
Author Correction: SLX4 interacts with RTEL1 to prevent transcription-mediated DNA replication perturbations
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