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Improving the performance of mechanical components and reducing machine energy consumption involves the correct selection of lubricants and their contact surfaces. The use of biodegradable hydraulic fluids along with less environmental impact surfaces is one example. In this sense, the following paper aims to analyze the behavior of mineral oil (HLP) and biodegradable oils (HEPR and HETG) submitted to a sliding with pins manufactured in PTFE and Al2O3 against a flat substrate coated with FeCrNiMo by the Laser Directed Energy Deposition (L-DED) process. Coatings by this replacement deposition process are proving to be a promising alternative in the replacement of hard chromium, a harmful material to human health. The slip tests were performed in a pin-on-disk tribometer using different loads in order to assess lubrication and wear regimes. In the tests, the average of the friction coefficients (μ) obtained was μHETG = 0.072, μHLP = 0.026 and μHEPR = 0.011, besides well-defined lubrication regimes. In the wear analysis, it was observed that the highest concentrations of Zn and P additives, found in HEPR, reduced surface damage. The main wear mechanisms identified were scratching, microcracking, microploughing and detachment. Consistent with the results mentioned, the largest volume removed from the coating was with the use of HETG vegetable oil, about 41% more than HEPR.

Este artigo discute a prática do hacking como expressão de um novo ativismo político, marcado pela incorporação dos hackers e das redes de comunicação. Para tanto, discute sobre as influências do anarquismo nessa militância política e remete-se aos coletivos WikiLeaks e Anonymous, a fim de identificar sua estrutura e modo de ação enquanto expressões do cyberativismo. A fim de lançar bases teóricas acerca do hacktivismo, levanta bibliograficamente reflexões sobre o tema. Conclui-se que o hacking é um novo ativismo político, pois visa a subversão da ordem de poder sobre a tecnologia e as formas de circulação de informação na sociedade global promovida pelo advento da internet., {"references":["CASTELLS, Manuel. Redes de indignação e esperança. Movimentos sociais na era da internet. Rio de Janeiro: Zahar, 2013.","COSENTINO, Carlo. O Direito do Trabalho na Revolução Informacional e nas Teorias dos Movimentos Sociais: impactos no postulado autonomia, nas relações individuais e coletivas de trabalho. 2017. Tese (Doutorado em Direito) – Programa de Pós-Graduação em Direito, Universidade Federal de Pernambuco, Recife, 2017.","FOUCAULT, Michael. Vigiar e punir: nascimento da prisão. Tradução Lígia M. Pondé Vassalo. Petrópolis, RJ: Vozes, 1977","ZERZAN, J. ‎Future Primitive: And Other Essays (Autonomedia New Autonomy). New York: Autonomedia, 1994.","GREEN ANARCHY COLLECTIVE. What is green anarchy? An introduction to anti-civilization anarchist thought and practice. Back to Basics, [s. l.], v. 4, n. 17, p. 35–41, 2004.","BOOKCHIN, Murray. Social Anarchism or Lifestyle Anarchism: an unbridgeable chasm. San Francisco, CA: AK Press, 1995. Disponível em: https://libcom.org/files/Social%20Anarchism%20or%20Lifestyle%20Anarchism.pdf. Acesso em: 15 jul. 2021.","JORDAN, Tim. Hacktivism: All Together in the Virtual. In: JORDAN, Tim. Activism!: Direct Action, Hacktivism and the Future of Society. London, UK: Reaktion Books Ltd., 2002. p. 119-137.","NAUGHTON, John. A brief history of the future: from radio days to Internet years in a lifetime. Woodstock, NY: Overlook Press. 2000.","EVANGELISTA, Rafael. O movimento software livre do brasil: política, trabalho e hacking. Horizontes Antropológicos, Porto Alegre, ano 20, n. 41, p. 173-200, jan./jun. 2014.","TAYLOR, Paul. A. Editorial: Hacktivism. The Semiotic Review of Books, [online], v. 12, n. 1, p. 1-9, 2001. Disponível em: http://projects.chass.utoronto.ca/semiotics/srb/Hacktivism.pdf. Acesso em: 15 jul. 2021.","CONWAY, Maura. Hackers as Terrorists? Why It Doesn't Compute? Computer Fraud and Security, United Kingdom, n. 12, p. 10-13, 2003. Disponível em: http://doras.dcu.ie/493/1/comp_fraud_12_2003.pdf. . Acesso em: 15 jul. 2021.","TAYLOR, Paul A. From Hackers to Hacktivists: Speed Bumps on the Global Superhighway?. New Media Society, United Kingdom, v. 7, n. 5, p. 625-646, 2005. Disponível em: http://atc.berkeley.edu/201/readings/PTaylor.pdf. Acesso em: 15 jul. 2021.","PAPADIMITRIOU, Fivos. A Geography of 'Notopia': Hackers et al., Hacktivism, Urban Cyber-Groups/Cyber-Cultures and Digital Social Movements. City, United Kingdom, v. 10, n. 3, p. 317-326, 2006. Disponível em: http://www.tandfonline.com/doi/pdf/10.1080/13604810600982289. Acesso em: 15 jul. 2021.","VAN LAER, Jeroen; VAN AELST, Peter. Internet and Social Movement Action Repertories: Opportunities and Limitations. Information, Communication & Society, United Kingdom, v. 13, n. 8, p. 1146-1171, 2010. Disponível em: http://www.academia.edu/262038/Internet_and_Social_Movement_Action_Repertoires_Opportunities_and_Limitations. Acesso em: 15 jul. 2021.","BEYER, Jessica L. The Emergence of a Freedom of Information Movement: Anonymous, WikiLeaks, the Pirate Party, and Iceland. Journal of Computer- Mediated Communication, Oxford, v. 19, n. 2, p. 141-154, 2014. Disponível em: http://onlinelibrary.wiley.com/doi/10.1111/jcc4.12050/abstract. Acesso em: : 15 jul. 2021.","FITRI, Nofia. Democracy Discourses Through the Internet Communication: Understanding the Hacktivism for the Global Changing. Online Journal of Communication and Media Technologies. 1(2): 1-20. 2011. Disponível em: http://www.academia.edu/1344217/Democracy_Discourses_through_the_Interne t_Communication_Understanding_the_Hacktivism_for_the_Global_Changing. Acesso em: 15 jul. 2021.","KRAPP, Peter. Terror and Play, Or What Was Hacktivism?. Grey Room, Massachusetts, n. 21, p. 70-93, 2005. Disponível em: http://www.academia.edu/307639/Terror_and_Play_or_What_Was_Hacktivism. Acesso em: 15 jul. 2021.","GILLEN, Martina. Human Versus Inalienable Rights: Is There Still a Future for Online Protest in the Anonymous World? European Journal of Law and Technology, Belfast, v. 3, n. 1, p. 1-19, 2012. Disponível em: http://eprints.uwe.ac.uk/21065/1/Gillen%20Human%20Rights.pdf. Acesso em: 15 jul. 2021.","WRAY, Stefan. Electronic Civil Disobedience and the World Wide Web of Hacktivism: A Mapping of Extraparliamentarian Direct Action Net Politics. Switch, Switzerland, v. 4, n. 2, 1998. Disponível em: http://switch.sjsu.edu/web/v4n2/stefan/. Acesso em: 15 jul. 2021.","JORDAN, Tim; TAYLOR, Paul. A Sociology of Hackers. The Sociological Review, United Kingdom, v. 46, n. 4, p. 757-780, 1998. Disponível em: http://onlinelibrary.wiley.com/doi/10.1111/1467-954X.00139/abstract. Acesso em: 15 jul. 2021","FUCHS, Christian. Anonymous: Hacktivism and Contemporary Politics. In: TROTTIER, Daniel; FUCHS, Christian (ed.). Social Media, Politics and the State. New York: Routledge, 2014. p. 88-106.","MANION, Mark; GOODRUM, Abby. Terrorism or Civil Disobedience: Toward a Hacktivist Ethic. ACM SIGCAS Computers and Society, [s. l.], v., 30, n. 2, p. 14-19, 2000; Disponível em: http://www.csis.pace.edu/cis101/CIS_101_Fall_2007_Spring_2008/LearningPodTopics/SocialResponsibility/Terrorism-or-Civil-Disobedience.pdf. Acesso em: 15 jul. 2021.","HIMMA, Kenneth Einar. Hacking As Politically Motivated Digital Civil Disobedience: Is Hacktivism Morally Justified?. Social Science Research Network, United States, p. 1-24, 2005. Disponível em: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=799545. Acesso em: 15 jul. 2021.","LEVY, Steven. Hackers: Heroes of the Computer Revolution. Sebastopol: O'Reilly Media, Inc., 2010.","LIRA, Isadora Teixeira de. Hacktivismo e organizações midiáticas: hackeamento de narrativas em WikiLeaks e mídia ninja. 2017. 105 f. Dissertação (Mestrado em Comunicação) – Programa de Pós-Graduação em Comunicação, Universidade Federal da Paraíba, João Pessoa, 2017.","LÉVY, Pierre (1996). O Que é Virtual?. Rio: Editora 34.","YIP, Michael; WEBBER, Craig. Hacktivism: A Theoretical and Empirical Exploration of China's Cyber Warriors. In: ACM WEB SCIENCE, 3., 2011, Koblenz. Proceedings […]. Koblenz: University of Southampton, 2011. Disponível em: https://eprints.soton.ac.uk/272350/2/hacktivism.pdf/. Acesso em: 15 jul. 2021.","FUCHS, Christian. The Anonymous Movement in the Context of Liberalism and Socialism. A Journal For and About Social Movements, v. 5, n. 2, p. 345-376, 2013. Disponível em: http://fuchs.uti.at/wp-content/Interface.pdf. Acesso em: 15 jul. 2021.","FUCHS, Christian. \"The Anonymous Movement in the Context of Liberalism and Socialism.\" A Journal For and About Social Movements 5(2): 345-376. Disponível em: (http://fuchs.uti.at/wp-content/Interface.pdf). Acesso em 15 de julho de 2021. 2013.","HEARN, Kay; MAHNCKE, Rachel J.; WILLIAMS, Patricia A. Culture Jamming: From Activism to Hacktivism. Australia: Cowan University, 2009. Disponível em: http://ro.ecu.edu.au/cgi/viewcontent.cgi?article=1002&context=isw. Acesso em: 15 jul. 2021.","MONGE, Yolanda. EUA acusam Assange de conspirar para se infiltrar em sistemas do Governo com informação classificada. El País, Washington, 11 abr. 2019. Disponível em: https://brasil.elpais.com/brasil/2019/04/11/internacional/1554994445_197405.html. Acesso em: 10 jan. 2022.","WONG, Wendy H.; BROWN, Peter A. E-Bandits in Global Activism: WikiLeaks, Anonymous, and the Politics of No One. American Political Science Association, United States, v. 11, n. 4, p. 1015-1033, 2013. Disponível em: http://politics.utoronto.ca/wp-content/uploads/2013/12/wong-and-brown-2013.pdf. Acesso em: 15 jul. 2021.","COLEMAN, Gabriella. Anonymous in Context: The Politics and Power behind the Mask. Waterloo: CIGI, 2013. Disponível em: http://www.cigionline.org/sites/default/files/no3_8.pdf. Acesso em: 15 jul. 2021.","HAI-JEW, Shalin. Action Potentials: Extrapolating an Ideology from the Anonymous Hacker Socio-Political Movement (A Qualitative Meta-Analysis). In: AKRIVOPOULOU, Christina; GARIPIDIS, Nicolaos. Digital Democracy and the Impact of Technology on Governance and Politics: New Globalized Practices. Hershey, PA: Information Science Reference, 2013. p. 51-107. Disponível em: http://krex.k-state.edu/dspace/bitstream/handle/2097/15352/Hai-JewIGI2013.pdf?sequence=1. Acesso em: 15 jul. 2021.","PORTAL DE NOTÍCIAS G1, 2020. Disponível em: https://g1.globo.com/politica/noticia/2020/06/02/grupo-de-hackers-vaza-em-rede-social-supostos-dados-pessoais-de-bolsonaro-filhos-e-apoiadores.ghtml. Acesso em 14 jul. 2021."]}

Implementing input parameters that match the experimental weld shape is challenging in LASER beam welding (LBW) simulation because the computed heat input and spot for temperature acquisition strongly affect the outcomes. Therefore, this study focuses on investigating the autogenous LBW of AISI 1020 using a three-dimensional heat transfer model that assumes a modified Gaussian heat flux distribution depending on LASER power (Qw), radius (R), and penetration (hp). The influence of such variables on the simulated weld bead was assessed through analysis of variance (ANOVA). The ANOVA returns reliable results as long as the data is normally distributed. The input radius exerts the most prominent influence. Taguchi’s design defined the studied data reducing about 65% of the simulations compared to a full factorial design. The optimum values to match the computed outcomes to lab-controlled experiments were 2400 W for power (80% efficiency), 0.50 mm for radius, and 1.64 mm for penetration. Moreover, the experimental errors regarding thermocouples positioning were corrected using linear interpolation. A parallel computing algorithm to obtain the temperature field reduces computational costs and may be applied in real-world scenarios to determine parameters that achieve the expected joint quality. The proposed methodology could reduce the required time to optimize a welding process, saving development and experimental costs.

The void level of a component produced by additive manufacturing can be used to predict the mechanical properties and in most cases it is important to develop processing methodologies able to minimize it. Conventional techniques include parameter optimization and the hot isostatic pressing (HIP). However, in the former there is a limit where improvement becomes minimal and the latter, although it is effective for internal voids, is not efficient in the case of voids located near the surface, which are considered critical. This paper describes a study in which laser remelting was used as an alternative to achieve higher densification after processing using directed energy deposition with laser (DED-L). This technique has been investigated for powder bed (PB) processes, but has not been explored for DED. Understanding the behavior of different materials considering the same processing parameters is also relevant and has not been previously addressed. An ytterbium (Yb) fiber laser with a maximum nominal power of 10 kW and wavelength of 1070 nm was used. Iron and Inconel 625 powders were deposited on an SAE 1010 steel substrate to form beads with intentional voids. The DED-L was performed with a power of 450 W, scanning speed of 600 mm/min and powder feed rate of 10 g/min. The laser radiation was applied over the produced surface at three energy levels: 31.5 kJ/m, 38.2 kJ/m and 45 kJ/m. An in-house MATLAB image processing code was developed in order to assess the void percentage. The results indicated that most of the voids originating from the DED-L process were due to lack of fusion between beads and between the deposit and the substrate. For iron, the void percentage after DED-L varied between 5.3% and 7.1%. After remelting, this value reduced to 1.7% applying 45 kJ/m. It was also noted that in all samples the voids that were initially connected to the surface coalesced because of material redistribution. However, a low repeatability was observed. For Inconel, the void percentage after DED-L varied between 4.4% and 7.1%, and reduced to 3.7% applying 31.5 kJ/m. This reduction is not as significant as that observed for iron and also the degree of dispersion was lower for iron. Hence, laser remelting is able to mitigate voids resultant from DED-L and, consequently, achieve better quality due to a lower probability of component failure. Simultaneously, productivity can be enhanced since the equipment required is the same as that used for the deposition. However, new strategies are needed to increase the process robustness and reduce the degree of dispersion.

Laser directed energy deposition with powder (pDED-L) is one of the most popular techniques for additive manufacturing. However, for some applications, the resulting surface finish requires post-processing machining. Laser remelting processing has been cited as a means of decreasing machining needs in other applications. The objective of this study was to assess the performance and gain a better physical understanding of the laser remelting process as an alternative to the conventional post-processing techniques applied after pDED-L. pDED-L and remelting were performed using a 10 kW fiber laser source and iron and Inconel 625 powders as feedstock to compare the surface roughness and waviness under different processing conditions (three heat input levels). Through 2D and 3D surface measurements, as well as scanning electron microscopy (SEM), surface features were qualified and quantified. SEM and optical microscopy (OM) were also employed for metallurgical characterization of the roughness. The surface micro-notch effect was assessed through the stress concentration factor (kt). The results indicated attenuation of the average roughness (Ra) by around 30% for iron and 70% for Inconel when laser remelting was employed. In addition, kt presented a 31% reduction for iron and 29% reduction for Inconel. The performance varied according to the type of material used and was mainly related to differences in thermal diffusivity and electrical resistivity. It was concluded that laser remelting is a promising technology for coupling with pDED-L aimed at producing 3D metal components with superior quality while allowing a faster production rate in comparison to current practices.

Funder: Conselho Nacional de Desenvolvimento Científico e Tecnológico, Funder: Fundação de Amparo à Pesquisa do Estado de Minas Gerais, Interleukin-1 receptor-associated kinases (IRAKs) -4, -2, and -1 are involved in transducing signals from Toll-like receptors (TLRs) via the adaptor myeloid differentiation primary-response protein 88 (MYD88). How MYD88/IRAK4/2/1 complexes are formed, their redundancies, and potential non-enzymatic roles are subjects of debate. Here, we examine the hierarchical requirements for IRAK proteins in the context of TLR4 activation and confirmed that the kinase activity of IRAK4 is essential for MYD88 signaling. Surprisingly, the IRAK4 scaffold is required for activation of the E3 ubiquitin ligase TNF receptor-associated factor 6 (TRAF6) by both MYD88 and TIR domain-containing adaptor protein inducing IFN-β (TRIF), a unique adaptation in the TLR4 response. IRAK4 scaffold is, therefore, essential in integrating MYD88 and TRIF in TLR4 signaling.

Tendo em vista, as altas taxas de acidentes automobilísticos ocorridos na região nordeste, especialmente levando em consideração a incidência de internações pelo fato dos Traumas Raquimedulares, ressalta-se portanto, a importância deste estudo, dada na qual os acidentes de trânsito são uma das principais causas de mortalidade. Assim, o objetivo da pesquisa foi avaliar a incidência dos casos de Traumas Raquimedulares causados por acidentes de trânsitos na região nordeste. O método utilizado para o estudo foi uma análise transversal. A realização da coleta de dados ocorreu entre os meses de Janeiro e Fevereiro de 2023, utilizando o Sistema de Informações Hospitalares do SUS (SIH/SUS) e o Banco de Dados do Sistema Único de Saúde (DATASUS). Os resultados obtidos apontam que a região que menos notificou os casos de TRM foi a região Centro-Oeste, com um resultado total de 514 casos confirmados nos últimos 3 anos. Estes dados apontam à necessidade de intensificar e delimitar estes achados, visto que, é necessário conhecer os principais fatores responsáveis por estes resultados e delimitar os Estados que mais possuem evidências e notificações de Acidentes de Trânsitos com Traumas Raquimedulares. Nesse desfecho, delimitou-se as pesquisas, utilizando-se os Estados da região nordeste para avaliar as notificações.

Welding processes are present in all sectors of the industry, highlighting the manufacturing industry of thick plates and pipelines. In these applications, welding processes have a major influence on costs, schedules, risk analysis and project feasibility. Conventional arc welding processes, such as the gas metal arc welding (GMAW) process, have limitations when applied to high thickness joints due to their maximum achievable penetration depth. On the other hand, the laser beam welding (LBW) welding process, despite reaching high penetration depths, has several limitations mainly regarding the geometric tolerance of the joint. In this regard, the hybrid laser-arc welding (HLAW) process emerges as a promising bonding process, combining the advantages of the GMAW and LBW processes into a single melting pool. Despite the many operational and metallurgical advantages, the HLAW process presents a high complexity due to the high number of parameters involved and the interaction between the laser beam and the electric arc. The present work discusses the challenges involved in the parametrization of the HLAW process applied to the joining of thick plates and pipes, and empirically evaluated a comparison between the HLAW and GMAW processes, showing a reduction of operating time of approximately 40 times, and a reduction of consumption of shielding gas and filler material of approximately 20 times, evidencing the technical and financial contribution of the hybrid process.

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Este trabalho é parte de um estudo interdisciplinar que tematiza o “discurso dos missionários dominicanos sobre os indígenas do Araguaia na Revista Cayapós e Carajás na primeira metade do século XX”. Dessa forma, o texto narra o contexto histórico das relações interétnicas na margem do Araguaia Paraense, e discute a migração e sua territorialização, tendo como referencial teórico a própria literatura dominicana, além de textos de viajantes e pesquisadores. A metodologia adotada compõe uma revisão da literatura em uma perspectiva qualitativa do corpus documental, além da classificação, sistematização e tematização, tendo os missionários, indígenas e sertanejos em situação de fronteira como foco. Ao se analisar o discurso missionário, foi possível perceber seu viés notadamente ideológico, próprio da dinâmica da representação sobre o indígena e sobre sertanejo do “Araguaia Paraense”.

Ni-Cr-B-Si alloy coatings deposited by the laser cladding process have high tribological resistance, good metallurgical bonding with the substrate, and an interesting set of mechanical properties. Aiming to correlate microstructure and the mechanical behavior of coatings in wear environments, three coatings were deposited over an ASTM A36 carbon steel substrate, them being C1 (1.05 kW–5 mm s−1), C2 (1.40 kW–21.7 mm s−1), and C3 (1.75 kW–30 mm s−1). The microstructure and microhardness of the coatings were analyzed, the former by using SEM and EDS. Ball-on-disk tests were performed to determine wear and friction coefficients. In order to evaluate the worn surfaces, SEM-EDS techniques were also employed. The different solidification rates affected the behavior of microstructure and microhardness. Coating C1, deposited with a lower cooling speed, provided a longer dwell time for the nucleation and growth of Cr-carbides (CrC) in the Ni-matrix, a factor that gave it a lower dilution, higher carbide concentration, and higher microhardness when compared to C2 and C3. In the ball-on-disk test, coatings with higher concentration and CrC size presented a higher variaton of their friction coefficient, but a lower volumetric loss and wear coefficient. Analysis of the worn surfaces showed that the CrC characteristics, deterioration of tribolayers, and coating material detachment close to the solidification cracks were the main features that change the coatings’ tribological performance.

In this article, the tribological behavior and energy efficiency of surfaces coated with WC-CoCr/HVOF were evaluated after a laser remelting process, using low and high laser energy densities, respectively, 33.3 and 150 J/mm2. The purpose of laser remelting was to adequately modify the microstructure of the coatings and promote better performance during surface sliding. Therefore, the microstructure, phase composition and microhardness of the coatings were investigated, and heat effect on the substrate. During dry and lubricated tribological tests, friction coefficient (COF), wear, and surface roughness also were evaluated. In the dry tests, friction, wear and heat dissipation energies were obtained, which were then correlated with the energy consumed by the tribometer. A HEPR-type biodegradable oil was used in the lubricated tests. The proper formation of W2C and Co3W3C, obtained for the lower energy density, increased the hardness, without weakening the material, while the CrC phase acted as an anti-wear barrier. Whereas for the high energy density, thermal decomposition produced fragile phases, which were easily removed from the matrix during the wear test. The sample tested in as-sprayed condition had a high adhesion and friction compared to the remelted samples. On the remelted surfaces, greater friction stability was obtained. The lower dry friction was not linked to the lower power consumption, a result which was then attributed to the higher heat dissipation from the surface during the tests. Finally, this study proposes a methodology for quantifying the efficiency of sliding surfaces and points to a sustainable solution for tribology.

Hardfacing of Ni and Co-based alloys has been widely applied to extend the lifespan of components that operating under severe conditions. The recent development of computational tools, such as Scorpeta from Oerlikon Metco, has allowed the design of alloys with customized properties. Metco 1040® (Fe-V-Mn-C) is a novel hardfacing alloy designed by the Scorpeta process to improve the abrasion and impact resistance of manganese steel substrates. However, few authors have addressed its wear performance. Therefore, the purpose of this study was to evaluate the effect of the processing parameters on the microstructure and wear resistance of the Metco 1040® alloy deposited by laser cladding on Hadfield steel. Single beads were deposited on Hadfield steel substrates according to a full factorial design of experiment (DOE), in which the laser power and deposition scanning speed were varied with 3 levels (32). Using some selected parameters, areas were covered by depositing parallel beads with an overlap of 30%, aimed at assessing the wear resistance through the “pin on drum” test. On applying the response surface method, it was found that the observed effects of the processing parameters (laser power and scanning speed) on the bead geometry (height, width and dilution) corroborate the current literature. For a given scanning speed, the higher the laser power the larger the carbide size and interdendritic spacing will be. The deposition parameters had no significant effect on the hardness or wear resistance of the coatings. However, the coating performance was significantly higher than that of Hadfield steel substrate. The findings reported herein suggest that the Metco 1040 alloy can be used to extend the lifespan of components of Hadfield steel.

Nos anos 90, a globalização criou um novo paradigma económico, provocando rápidas mudanças no ambiente institucional. Desta maneira, a estrutura da política econômica adotada pelo governo coreano, desde o início dos 60, não condizia mais com a expansão de novos segmentos industriais - que caracterizam a Nova Economia. Nesta última década, a Coreia aderiu à liberalização financeira de forma rápida demais, sem que suas estruturas estivessem aptas para absorver essas mudanças. Assim, o país subestimou a importância dos fatores que estavam embutidos na liberalização - sobretudo, da regulamentação financeira, de uma estrutura jurídica eficiente e das relações econômico-institucionais vigentes então. Desta forma, a liberalização rápida mal conduzida do mercado financeiro e a obsolescência do modelo de crescimento coreano fizeram eclodir a crise monetária coreana. In the 90s, the globalization has created a new economic paradigm, causing quick changes in the institutional environment. In this way, the political economic adopted by Korean government, that has begun since beginning of 60s, no more was adherent with new industry segments of New Economy. In the last decade, Korea has adhered to financial liberalization rapidly, without being prepared, id est, underestimating the factors were incorporated in liberalization, such, financial regulation, efficient legal structure and current economy institutional relation. Hence, the quick liberalization of financial market badly sequenced and the outdated Korean growth model came out to the Korean currency crises.

A estruturação e texturização de superfícies via laser pulsado é uma alternativa de processo para modificação de superfícies que, a partir da incidência de feixes de laser, gera padrões topográficos periódicos (texturas), alterando as características funcionais das superfícies de produtos e componentes. No segmento odontológico, implantes dentários demandam características específicas de suas superfícies, para favorecimento do processo de osseointegração. Considerando a gama de tipos de laser, bem como de características de materiais e superfícies, a verificação da influência de parâmetros do laser pulsado, sobre características específicas de tais superfícies, pode contribuir para desenvolvimento de estratégias de projeto e manufatura de superfícies cada vez mais favoráveis e robustas para suas aplicações. Neste trabalho, foi utilizado o laser de fibra de itérbio para modificação de superfícies da liga Ti-6Al-4V, observando características superficiais associadas à implantes dentários. Para tanto, foi delineado um experimento fatorial, com três fatores (parâmetros do laser pulsado: velocidade, potência e número de passes) e dois níveis (limites mínimos e máximos). As superfícies foram processadas com velocidade de 35 e 140 mm/s; potência de 50% e 100%; e 1 e 4 passes. É apresentada a metodologia para caracterização das superfícies. As superfícies foram caracterizadas, em termos de: rugosidade, topografia, molhabilidade, composição química e integridade; sendo diretamente correlacionadas com os três parâmetros do laser pulsado. Verificou-se que: as diferentes combinações entre os três parâmetros do laser pulsado influenciaram as características observadas nas amostras processadas. O aumento da velocidade e do número de passes contribuiu para o aumento da rugosidade, enquanto o aumento da potência causou sua redução. Topografias com características específicas foram verificadas para cada combinação de parâmetros. Em termos de molhabilidade, a partir da variação dos parâmetros, algumas superfícies enfatizaram seu caráter hidrofóbico, outras passaram a ter caráter hidrofílico. A variação de parâmetros alterou o comportamento da formação de óxidos na região ressolidificada. Não foram observadas alterações que comprometam a integridade das superfícies. The structuring and texturing of surfaces by pulsed laser is an alternative process for surface modification that, from the incidence of laser beams, generates periodic topographic patterns (textures), changing the functional characteristics of the surfaces of products and components. In the dental segment, dental implants demand specific characteristics of their surfaces, to favor the osseointegration process. Considering the range of laser types, as well as material and surface characteristics, verifying the influence of pulsed laser parameters on specific characteristics of such surfaces can contribute to the development of increasingly favorable surface design and manufacturing strategies and robust for your applications. In this work, the ytterbium fiber laser was used to modify the surfaces of the Ti-6Al-4V alloy, observing surface characteristics associated with dental implants. Therefore, a factorial experiment was designed, with three factors (pulsed laser parameters: speed, power and number of passes) and two levels (minimum and maximum limits). The surfaces were processed with speed of 35 and 140 mm/s; 50% and 100% potency; and 1 and 4 passes. The methodology for surface characterization is presented. The surfaces were characterized in terms of roughness, topography, wettability, chemical composition and integrity; being directly correlated with the three pulsed laser parameters. It was found that: the different combinations between the three pulsed laser parameters influenced the characteristics observed in the processed samples. The increase in speed and number of passes contributed to the increase in roughness, while the increase in power caused its reduction. Topographies with specific characteristics were verified for each combination of parameters. In terms of wettability, from the variation of parameters, some surfaces emphasized their hydrophobic character, others began to have a hydrophilic character. The variation of parameters changed the behavior of oxide formation in the resolidified region. Changes that compromise the integrity of the surfaces were not observed.