A Study on Binary Asteriod System Deflection

The study of asteroids, its composition and trajectories, has been a persistent interest in the space exploration community. In addition, they are also perceived as a great threat to life on Earth, considering the possibility of an impact with our planet. A considerable portion, around 15%, of the asteroid population are believed to be part of a double or triple asteroid system

Substituting conventional steel alloys by carbon fibre composites in structural parts of an existing laser cutting equipment

In the present work, a finite element (FE) analysis was employed to validate the use of advanced carbon fibre composites as replacement of traditional low-alloy steel in the construction of the main runway frame structure of a laser cutting equipment currently available in the market. This new composite solution was adopted to increase the current laser equipment precision and cutting speed. The main objective was to enhance the machine cutting performance by using much stiffer and lighter main structural runway frames to support the machine cutting head and all major laser beam mirrors and lens, which allows decreasing dramatically the inertial and vibration efforts developed in service through the use of carbon fibre composites. The paper presents, compares and discusses the mechanical and dynamical behaviour obtained in the FE simulations made by using both solutions, the current one based on a steel frame and the new innovative composite adopted structure. The processing method to be used in the production of the innovative composite structure is also proposed. Finally, as production costs may also have an important impact on final equipment commercial price and acceptation, an economical study considering both manufacturing situations (currently used and new one) are discussed

Drying colloidal systems: laboratory models for a wide range of applications

The drying of complex fluids provides a powerful insight into phenomena that take place on time and length scales not normally accessible. An important feature of complex fluids, colloidal dispersions and polymer solutions is their high sensitivity to weak external actions. Thus, the drying of complex fluids involves a large number of physical and chemical processes. The scope of this review is the capacity to tune such systems to reproduce and explore specific properties in a physics laboratory. A wide variety of systems are presented, ranging from functional coatings, food science, cosmetology, medical diagnostics and forensics to geophysics and art

CO2 Vertical Profiles on Four Sites over Amazon from 2019 to 2020

To improve diagnosis of Amazonia's carbon cycle, we present a 2 year data (2019 to 2020), complementary to our previosly 9 years (2010 to 2018) observations of lower troposphere CO2 concentrations performed regularly at four aircraft vertical profiling sites spread over the Brazilian Amazonia (Gatti et al., 2021). The four sites from the CARBAM project at Amazonia: SAN (2.86S 54.95W); ALF (8.80S 56.75W); RBA (9.38S 67.62W) and TEF (3.39S 65.6W), started in 2013. The sampling period was typically twice per month (Gatti et al., 2021; Gatti et al., 2014; Basso et al., 2016; Miller et al., 2007; d'Amelio et al., 2009; Domingues et al., 2020). From 2019 to 2020, a total of 141 vertical profiles from 4420 m to 300 m asl. was performed at the 4 sites. The vertical profiles were usually taken between 12:00 and 13:00 local time. Air is sampled by semi-automatic filling of 0.7 L boro-silicate flasks inside purpose-built suitcases (PFP -Programmable Flask Package) (Tans et al., 1996); there are two versions, one with 17 flasks at SAN, and another with 12 flasks at TEF, ALF and RBA. This suitcase is connected to a compressor package (PCP –Portable Compressor Package), containing batteries and 2 compressors, which is connected to an air inlet on the outside of the aircraft at wing or window, depending on the aircraft model. Once a PFP (i.e. one vertical profile) has been filled with air the PFP is transported to the INPE/ LaGEE(Instituto Nacional de Pesquisas Espaciais/Greenhouse Gases Laboratory), in Sao Jose dos Campos, Sao Paulo state, Brazil. This laboratory is a replica of the NOAA/ESRL/GMD trace gas analysis system at Boulder, Colorado, USA, and was constructed in 2003 and sent to IPEN where started the analysis in 2004.Air samples were analysed with a non-dispersive infrared (NDIR) analyser for CO2. To ensure the accuracy, we construct a calibration curve every 2 samples. The calibration curve constructed with 3-standards concentrations, produced by NOAA/ESRL/GMD. The “High” (10 ppm higher than medium), “medium” (similar to mean CO2 concentration founded in Amazonia), and “Low” (10 ppm lower than medium). We have an intercomparison program with NOAA at Natal site (5S, 35W, located at Brazilian northeast coast) where the comparison IPEN/INPE-NOAA was -0.05 ± 0.38ppm. The precision is analysed based on CO2mole fraction from “target tanks” (calibrated CO2in air in high pressure cylinders treated as unknowns by NOAA) and demonstrated long-term repeatability of 0.03ppm and a difference between measured and calibrated values of 0.03 ppm. Additional information can be shared from the LaGEE/INPE group as temperature, precipitation, and others parameters used by the group for the Nature paper entitled “Decrease in Amazonia carbon uptake linked to trends in deforestation and climate” (Gatti et al, 2021)

Percurso histórico-epistemológico dos estudos de citação no Brasil

Resumo Este artigo apresenta a trajetória histórica e epistemológica dos estudos de citação no Brasil por meio dos artigos de periódicos nacionais. Tem como justificativa a ausência de pesquisas que apontem o estado da arte dos estudos de citação no Brasil, bem como a importância dos seus resultados para a compreensão da dinâmica dos contextos de produção e comunicação da ciência. O objetivo da pesquisa é identificar e discutir os elementos que configuram a trajetória histórica e epistemológica dos estudos de citação no Brasil presentes nos artigos indexados na Base de Dados Referencial de Artigos de Periódicos em Ciência da Informação, de 1972 a 2014. A pesquisa, de natureza descritiva, utilizou a técnica de análise de conteúdo para sistematização temporal e teórico-metodológica dos elementos constantes dos artigos publicados ao longo de quarenta anos. Discute as características e as configurações dos estudos de citação com base: (a) nos dois períodos: embrionário e emergente; e (b) nos enfoques teóricos: normativo, construtivista e sociocultural. Sinaliza o estágio do percurso histórico e epistemológico dos estudos de citação e lança perspectivas para os próximos trabalhos relacionados à temática