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1.
Quantification of natural rubber blends by reflection/reflectance infrared and confocal Raman spectroscopy: a comparison of statistical methods reflectionreflectance reflection reflectance spectroscopy
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PASSERO, ALAN
; FERREIRA, KARYN M.
; DINIZ, MILTON F.
; SANCHES, NATALIA B.
; AMADO, JAVIER CARLOS Q.
; DUTRA, RITA DE CÁSSIA L.
.
Abstract The blend of butadiene and acrylonitrile copolymer (NBR) with natural poly-cis-isoprene (NR) shows increased resistance to swelling in solvents in comparison to the individual components. In aerospace, NBR rubber is used as thermal protection for rockets and shall not contain other polymers, even in low contents, otherwise, it can affect the protection performance and rocket safety by causing detachment of the elastomer/propellant interface; therefore, this investigation presents methodologies to determine the NR/NBR contents. This study explores different analytical techniques, such as Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy, in the mid-infrared (MIR) by reflection and in the near-infrared by reflectance (NIRA) modes, Furthermore, quantification strategies by univariate, bivariate and multivariate (chemometric) models are evaluated and compared. A proposed methodology, based on multivariate Raman microscopy with partial least squares regression (PLS), showed high linearity (R2 > 0.99) and low error (< 0.82 %). The validation of FT-MIR data for the CH3, which presented lower error (1.3%) than vinylidene band (6%), showed that both methodologies (reflection and NIRA reflectance) can be used for the quantification of NR in NR/NBR. These results constitute a contribution to the state of the art in researching industrial and aerospace elastomeric applications. (NBR polycisisoprene poly cis isoprene (NR components polymers contents otherwise elastomerpropellant elastomer propellant interface therefore NRNBR techniques FTIR (FTIR midinfrared mid MIR (MIR nearinfrared near (NIRA modes Furthermore univariate chemometric (chemometric compared methodology PLS, PLS , (PLS) R2 R (R 0.99 099 0 99 < ( 082 82 0.8 %. % . %) FTMIR FT CH3 CH 1.3% 13 1 3 (1.3% 6%, 6 6% (6%) applications (PLS 0.9 09 9 08 8 0. 1.3 (1.3 (6% 1. (1. (6 (1
2.
Synthesis and characterization of Poly(urea-formaldehyde) microcapsules with 5-ethylidene-2-norbornene as self-healing agent and potential use in polymeric composites Polyureaformaldehyde Poly urea formaldehyde Poly(urea-formaldehyde 5ethylidene2norbornene ethylidenenorbornene 5 ethylidene 2 norbornene selfhealing self healing
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ROSSI, SABRINA SARA
; CARRARA, ALEXANDRE ESTEVÃO
; COSTA, MARIA CAROLINA B.
; MARTINS, CAIO LUCAS G.P.
; DUTRA, RITA DE CÁSSIA L.
; DUTRA, JORGE CARLOS N.
.
Anais da Academia Brasileira de Ciências
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Abstract This study describes a methodology to prepare and characterize PUF [poly(urea formaldehyde)] microcapsules containing 5-ethylidene-2-norbornene (ENB) as self-healing agent, as well as the compatibility evaluation of ENB in the presence of Grubb’s catalyst with an epoxy matrix. First, the results of an adhesion assay by lap shear proved chemical compatibility between the epoxy matrix and self-healing agent in the presence of Grubb’s catalyst. After evaluating the chemical compatibility, microcapsules with ENB were synthesized in an oil-in-water emulsion system. Thereafter, the microcapsules were morphologically, chemically and thermally characterized in which a granulometric dispersion between 30-140 μm and an average size of 69.8 ± 4.9 μm were observed. The SEM (scanning electron microscope) results showed that the average thickness of microcapsules shell was 3.6 ± 0.4 μm. The thermogravimetric analysis (TGA) showed that microcapsules are susceptible to rupture and consequent ENB release in temperatures greater than 230 °C, demonstrating that microcapsules are suitable for applications in materials with self-healing capacity. polyurea poly urea formaldehyde formaldehyde) 5ethylidene2norbornene ethylidenenorbornene 5 ethylidene 2 norbornene (ENB selfhealing self healing Grubbs Grubb s First oilinwater oil water system Thereafter morphologically 30140 30 140 30-14 698 69 8 69. 49 4 9 4. observed scanning microscope 36 3 6 3. 04 0 0. TGA (TGA 23 C °C capacity 3014 14 30-1 301 1 30-
3.
Infrared quantification of binary rubber blends with overlapping bands
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BARROS, ALEXANDRA HELENA DE
; MURAKAMI, LIDIA M.S.
; MAGALHÃES, RACHEL F.
; TAKEMATSU, MARCIA M.
; DINIZ, MILTON F.
; SANCHES, NATÁLIA B.
; DUTRA, JORGE CARLOS N.
; DUTRA, RITA DE CÁSSIA L.
.
Abstract Quantification of elastomer content for the ethylene-propylene diene monomer/polybutadiene blend are seldom subjects in the literature, mainly due to rubber compatibility problems. However, suitable blend contents can lead to desirable properties. Infrared spectroscopy can quantify this type of blend even if some bands overlap, which can be resolved with the proper choice of spectrum obtaining mode and non-overlapping analytical bands. This study evaluates the ethylene-propylene diene monomer/polybutadiene blend quantification by transmission, reflection and transflectance infrared. Even though all of the methodologies showed satisfactory results, transmission mode provided better accuracy. The methodology is simple and suited for the rubber industry. The sample with the higher BR content provided the best result. The band at 743 cm-1 is weak and results in even weaker absorptions when measuring samples with low BR content. On the other hand, the developed methodologies provided an accurate determination of low EPDM contents. For infrared spectroscopy researchers, these results not only encourage using different spectra obtaining modes application, including less conventional ones such as transflectance in the near infrared region for quantitative determination, it also contributes to a wide discussion of errors in the developed methodologies, which are also seldom discussed in publications. ethylenepropylene ethylene propylene monomerpolybutadiene monomer polybutadiene literature problems However properties overlap nonoverlapping non overlapping accuracy industry result 74 cm1 cm 1 cm- hand researchers application publications 7
4.
Impact assessment of synthesis parameter stirring speed in final physicochemical properties of PU microcapsules incorporated into epoxy matrixes
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CARRARA, ALEXANDRE ESTÊVÃO
; RODRIGUES, VINÍCIUS HENRIQUE DE S.
; DUTRA, RITA DE CÁSSIA L.
; DUTRA, JORGE CARLOS N.
.
Abstract A considerable number of papers have been published to assess self-healing capacity of several materials, as well as several applications in different areas. However, the impact assessment of changing synthesis parameters of microcapsules, hollow fibers or microvascular systems in its final physicochemical properties are still an emerging research field. This current paper presents a synthesis process of PU microcapsules containing TDI as core agent and the characterization of microcapsules physicochemical properties. During the synthesis, the reaction parameter stirring speed was changed to assess the impact that this parameter has in the final microcapsules’ physicochemical properties. Microcapsules were characterized by FT-IR, TGA and image analysis (OM and SEM). Additionally, microcapsules were incorporated to an epoxy matrix (5% weight/weight) to assess the impact in the final physicochemical and mechanical matrix properties. Epoxy-based test specimens were also obtained within aramid and silica, which are traditional reinforcing loads in rubber synthesis. Final mechanical properties of matrixes within aramid and silica were compared to the properties of matrixes within microcapsules to determine what kind of behavior the microcapsules have when incorporated to epoxy matrixes. selfhealing self healing materials areas However field FTIR, FTIR FT IR, IR FT-IR OM SEM. SEM . SEM) Additionally 5% 5 (5 weight/weight weightweight weight Epoxybased Epoxy based (
5.
[SciELO Preprints] - Guideline of the Brazilian Society of Cardiology on Diagnosis and Treatment of Patients with Chagas Disease Cardiomyopathy
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Marin-Neto, José Antonio
Rassi Jr., Anis
Moraes Oliveira, Gláucia M.
Lemos Correia, Luís Claudio
Novaes Ramos Jr., Alberto
Hasslocher-Moreno, Alejandro Marcel
Luquetti Ostermayer, Alejandro
Sousa, Andréa Silvestre de
Amato Vincenzo de Paola, Angelo
Sobral de Sousa, Antonio Carlos
Pinho Ribeiro, Antonio Luiz
Correia Filho, Dalmo
Moraes de Souza, Dilma do Socorro
Cunha-Neto, Edecio
J. A. Ramires, Felix
Bacal, Fernando
Pereira Nunes, Maria do Carmo
Martinelli Filho, Martino
Ibrahim Scanavacca, Maurício
Magalhães Saraiva, Roberto
Alves de Oliveira Júnior, Wilson
M. Lorga-Filho, Adalberto
de Jesus Benevides de Almeida Guimarães, Adriana
Lopes Latado Braga, Adriana
Sarmento de Oliveira, Adriana
V. L. Sarabanda, Alvaro
Yecê das Neves Pinto, Ana
Assis Lopes do Carmo, André
Schmidt, André
Costa, Andréa Rodrigues da
Ianni, Barbara Maria
Markman Filho, Brivaldo
Eduardo Rochitte, Carlos
Thé Macedo, Carolina
Mady, Charles
Chevillard, Christophe
Bittencourt das Virgens, Cláudio Marcelo
Nery de Castro, Cleudson
De Paoli de Carvalho Britto, Constança Felícia
Pisani, Cristiano
do Carmo Rassi, Daniela
C. Sobral Filho, Dario
Rodrigues Almeida, Dirceu
A. Bocchi, Edimar
T. Mesquita, Evandro
de Souza Nogueira Sardinha Mendes, Fernanda
Pereira, Francisca Tatiana
Sperandio da Silva, Gilberto Marcelo
de Lima Peixoto, Giselle
Glotz de Lima, Gustavo
H. Veloso, Henrique
Turin Moreira, Henrique
Bellotti Lopes, Hugo
Masciarelli Francisco Pinto, Ibraim
Pinto Dias, João Carlos
Bemfica, João Marcos
Silva-Nunes, João Paulo
Soares Barreto-Filho, José Augusto
Kerr Saraiva, José Francisco
Lannes-Vieira, Joseli
Menezes Oliveira, Joselina Luzia
V. Armaganijan, Luciana
Martins, Luiz Cláudio
C. Sangenis, Luiz Henrique
Barbosa, Marco Paulo
Almeida-Santos, Marcos Antônio
Simões, Marcos Vinicius
Shikanai-Yasuda, Maria Aparecida
Vieira Moreira, Maria da Consolação
Higuchi, Maria de Lourdes
Costa Monteiro, Maria Rita de Cássia
Felix Mediano, Mauro Felippe
Maia Lima, Mayara
T. Oliveira, Maykon
Moreira Dias Romano , Minna
Nitz, Nadjar
de Tarso Jorge Medeiros, Paulo
Vieira Alves, Renato
Alkmim Teixeira, Ricardo
Coury Pedrosa, Roberto
Aras, Roque
Morais Torres, Rosália
dos Santos Povoa, Rui Manoel
Rassi, Sérgio Gabriel
Salles Xavier, Sérgio
Marinho Martins Alves , Silvia
B. N. Tavares, Suelene
Lima Palmeira, Swamy
da Silva Junior, Telêmaco Luiz
da Rocha Rodrigues, Thiago
Madrini Junior, Vagner
Maia da Costa , Veruska
Dutra, Walderez
This guideline aimed to update the concepts and formulate the standards of conduct and scientific evidence that support them, regarding the diagnosis and treatment of the Cardiomyopathy of Chagas disease, with special emphasis on the rationality base that supported it.nbsp;
Chagas disease in the 21st century maintains an epidemiological pattern of endemicity in 21 Latin American countries. Researchers and managers from endemic and non-endemic countries point to the need to adopt comprehensive public health policies to effectively control the interhuman transmission of T. cruzi infection, and to obtain an optimized level of care for already infected individuals, focusing on diagnostic and therapeutic opportunistic opportunities.
nbsp;
Pathogenic and pathophysiological mechanisms of the Cardiomyopathy of Chagas disease were revisited after in-depth updating and the notion that necrosis and fibrosis are stimulated by tissue parasitic persistence and adverse immune reaction, as fundamental mechanisms, assisted by autonomic and microvascular disorders, was well established. Some of them have recently formed potential targets of therapies.nbsp;
The natural history of the acute and chronic phases was reviewed, with enhancement for oral transmission, indeterminate form and chronic syndromes. Recent meta-analyses of observational studies have estimated the risk of evolution from acute and indeterminate forms and mortality after chronic cardiomyopathy. Therapeutic approaches applicable to individuals with Indeterminate form of Chagas disease were specifically addressed. All methods to detect structural and/or functional alterations with various cardiac imaging techniques were also reviewed, with recommendations for use in various clinical scenarios. Mortality risk stratification based on the Rassi score, with recent studies of its application, was complemented by methods that detect myocardial fibrosis.nbsp;
The current methodology for etiological diagnosis and the consequent implications of trypanonomic treatment deserved a comprehensive and in-depth approach. Also the treatment of patients at risk or with heart failure, arrhythmias and thromboembolic events, based on pharmacological and complementary resources, received special attention. Additional chapters supported the conducts applicable to several special contexts, including t. cruzi/HIV co-infection, risk during surgeries, in pregnant women, in the reactivation of infection after heart transplantation, and others.nbsp; nbsp;nbsp;
Finally, two chapters of great social significance, addressing the structuring of specialized services to care for individuals with the Cardiomyopathy of Chagas disease, and reviewing the concepts of severe heart disease and its medical-labor implications completed this guideline.
Esta diretriz teve como objetivo principal atualizar os conceitos e formular as normas de conduta e evidências científicas que as suportam, quanto ao diagnóstico e tratamento da CDC, com especial ênfase na base de racionalidade que a embasou.
A DC no século XXI mantém padrão epidemiológico de endemicidade em 21 países da América Latina. Investigadores e gestores de países endêmicos e não endêmicos indigitam a necessidade de se adotarem políticas abrangentes, de saúde pública, para controle eficaz da transmissão inter-humanos da infecção pelo T. cruzi, e obter-se nível otimizado de atendimento aos indivíduos já infectados, com foco em oportunização diagnóstica e terapêutica.
Mecanismos patogênicos e fisiopatológicos da CDC foram revisitados após atualização aprofundada e ficou bem consolidada a noção de que necrose e fibrose sejam estimuladas pela persistência parasitária tissular e reação imune adversa, como mecanismos fundamentais, coadjuvados por distúrbios autonômicos e microvasculares. Alguns deles recentemente constituíram alvos potenciais de terapêuticas.
A história natural das fases aguda e crônica foi revista, com realce para a transmissão oral, a forma indeterminada e as síndromes crônicas. Metanálises recentes de estudos observacionais estimaram o risco de evolução a partir das formas aguda e indeterminada e de mortalidade após instalação da cardiomiopatia crônica. Condutas terapêuticas aplicáveis aos indivíduos com a FIDC foram abordadas especificamente. Todos os métodos para detectar alterações estruturais e/ou funcionais com variadas técnicas de imageamento cardíaco também foram revisados, com recomendações de uso nos vários cenários clínicos. Estratificação de risco de mortalidade fundamentada no escore de Rassi, com estudos recentes de sua aplicação, foi complementada por métodos que detectam fibrose miocárdica.
A metodologia atual para diagnóstico etiológico e as consequentes implicações do tratamento tripanossomicida mereceram enfoque abrangente e aprofundado. Também o tratamento de pacientes em risco ou com insuficiência cardíaca, arritmias e eventos tromboembólicos, baseado em recursos farmacológicos e complementares, recebeu especial atenção. Capítulos suplementares subsidiaram as condutas aplicáveis a diversos contextos especiais, entre eles o da co-infecção por T. cruzi/HIV, risco durante cirurgias, em grávidas, na reativação da infecção após transplante cardíacos, e outros.nbsp;nbsp;nbsp;
Por fim, dois capítulos de grande significado social, abordando a estruturação de serviços especializados para atendimento aos indivíduos com a CDC, e revisando os conceitos de cardiopatia grave e suas implicações médico-trabalhistas completaram esta diretriz.nbsp;
6.
Qualitative and quantitative evaluation of epoxy systems by Fourier transform infrared spectroscopy and the flexibilizing effect of mercaptans
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JANZEN, DANIEL ANDERSON
; DINIZ, MILTON F.
; AZEVEDO, JOYCE B.
; PINTO, JULIANO R.A.
; SANCHES, NATÁLIA B.
; DUTRA, RITA DE CÁSSIA L.
.
Abstract Epoxy systems are widely applied as adhesives in the aerospace industry. They have excellent adhesion properties, however, being thermosetting, epoxy systems show fracture brittleness characteristics. Polysulfide and polymercaptans are good options to increase the flexibility of the epoxy adhesive. Thermal analysis techniques are generally used to evaluate the curing degree of epoxy systems. In most cases, when infrared (IR) analysis is used, it is employed qualitatively. This paper presents the reaction study of a DGEBA epoxy prepolymer with diethylenetriamine (DETA) and linear and branched dodecyl mercaptans as flexibilizers. Conversion data and curing time were assessed qualitatively and quantitatively by Fourier Transform Infrared Spectroscopy (FT-IR) in the medium infrared region (MIR) and in the near infrared region, using near infrared reflectance accessory (NIRA). NIRA methodology showed satisfactory results, with errors between 3 and 7%, especially in samples with lower amine contents. Mechanical tests confirmed the flexibilization of the cured epoxy system by the addition of mercaptans, indicating a lower crosslinking degree in the matrix. Young’s modulus (E) significantly decreased from 2017 MPa to 578 MPa with the addition of approximately 20 wt% of normal dodecyl mercaptan to the epoxy system.
https://doi.org/10.1590/0001-3765202120200799
277 downloads
7.
Expanded perlite/cork fillers applied to aerospace insulation materials
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PINTO, JULIANO R.A.
; SANCHES, NATALIA B.
; DINIZ, MILTON F.
; SANTOS, RÉGIS S.
; OLIVEIRA, JOSÉ I.S. DE
; DUTRA, RITA DE CÁSSIA L.
.
Abstract Insulations for rocket motors such as Flexible Thermal Protections (FTPs) and Rigid Thermal Protection (RTPs) act as thermal barriers against the hyperthermal environment from the solid propellant combustion. FTPs present dual function: to extend RTPs performance, and to attenuate the propellant contraction. FTPs used in the Brazilian Space Program have asbestos in their composition since the 70´s; however, they are hazardous for human health. In this context, a mixture of Expanded Perlite (PExp) and Cork Powder (CP) was investigated as a replacement for asbestos. Results showed reduction about 21 % in density and an increase of 13 % in the ablative properties. The low mechanical properties not interfere in this type of FTP due to your function of attenuate the propellant contraction.
https://doi.org/10.1590/0001-3765201820170964
1184 downloads
8.
Growing knowledge: an overview of Seed Plant diversity in Brazil
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Zappi, Daniela C.
; Filardi, Fabiana L. Ranzato
; Leitman, Paula
; Souza, Vinícius C.
; Walter, Bruno M.T.
; Pirani, José R.
; Morim, Marli P.
; Queiroz, Luciano P.
; Cavalcanti, Taciana B.
; Mansano, Vidal F.
; Forzza, Rafaela C.
; Abreu, Maria C.
; Acevedo-Rodríguez, Pedro
; Agra, Maria F.
; Almeida Jr., Eduardo B.
; Almeida, Gracineide S.S.
; Almeida, Rafael F.
; Alves, Flávio M.
; Alves, Marccus
; Alves-Araujo, Anderson
; Amaral, Maria C.E.
; Amorim, André M.
; Amorim, Bruno
; Andrade, Ivanilza M.
; Andreata, Regina H.P.
; Andrino, Caroline O.
; Anunciação, Elisete A.
; Aona, Lidyanne Y.S.
; Aranguren, Yani
; Aranha Filho, João L.M.
; Araújo, Andrea O.
; Araújo, Ariclenes A.M.
; Araújo, Diogo
; Arbo, María M.
; Assis, Leandro
; Assis, Marta C.
; Assunção, Vivian A.
; Athiê-Souza, Sarah M.
; Azevedo, Cecilia O.
; Baitello, João B.
; Barberena, Felipe F.V.A.
; Barbosa, Maria R.V.
; Barros, Fábio
; Barros, Lucas A.V.
; Barros, Michel J.F.
; Baumgratz, José F.A.
; Bernacci, Luis C.
; Berry, Paul E.
; Bigio, Narcísio C.
; Biral, Leonardo
; Bittrich, Volker
; Borges, Rafael A.X.
; Bortoluzzi, Roseli L.C.
; Bove, Cláudia P.
; Bovini, Massimo G.
; Braga, João M.A.
; Braz, Denise M.
; Bringel Jr., João B.A.
; Bruniera, Carla P.
; Buturi, Camila V.
; Cabral, Elza
; Cabral, Fernanda N.
; Caddah, Mayara K.
; Caires, Claudenir S.
; Calazans, Luana S.B.
; Calió, Maria F.
; Camargo, Rodrigo A.
; Campbell, Lisa
; Canto-Dorow, Thais S.
; Carauta, Jorge P.P.
; Cardiel, José M.
; Cardoso, Domingos B.O.S.
; Cardoso, Leandro J.T.
; Carneiro, Camila R.
; Carneiro, Cláudia E.
; Carneiro-Torres, Daniela S.
; Carrijo, Tatiana T.
; Caruzo, Maria B.R.
; Carvalho, Maria L.S.
; Carvalho-Silva, Micheline
; Castello, Ana C.D.
; Cavalheiro, Larissa
; Cervi, Armando C.
; Chacon, Roberta G.
; Chautems, Alain
; Chiavegatto, Berenice
; Chukr, Nádia S.
; Coelho, Alexa A.O.P.
; Coelho, Marcus A.N.
; Coelho, Rubens L.G.
; Cordeiro, Inês
; Cordula, Elizabeth
; Cornejo, Xavier
; Côrtes, Ana L.A.
; Costa, Andrea F.
; Costa, Fabiane N.
; Costa, Jorge A.S.
; Costa, Leila C.
; Costa-e-Silva, Maria B.
; Costa-Lima, James L.
; Cota, Maria R.C.
; Couto, Ricardo S.
; Daly, Douglas C.
; De Stefano, Rodrigo D.
; De Toni, Karen
; Dematteis, Massimiliano
; Dettke, Greta A.
; Di Maio, Fernando R.
; Dórea, Marcos C.
; Duarte, Marília C.
; Dutilh, Julie H.A.
; Dutra, Valquíria F.
; Echternacht, Lívia
; Eggers, Lilian
; Esteves, Gerleni
; Ezcurra, Cecilia
; Falcão Junior, Marcus J.A.
; Feres, Fabíola
; Fernandes, José M.
; Ferreira, D.M.C.
; Ferreira, Fabrício M.
; Ferreira, Gabriel E.
; Ferreira, Priscila P.A.
; Ferreira, Silvana C.
; Ferrucci, Maria S.
; Fiaschi, Pedro
; Filgueiras, Tarciso S.
; Firens, Marcela
; Flores, Andreia S.
; Forero, Enrique
; Forster, Wellington
; Fortuna-Perez, Ana P.
; Fortunato, Reneé H.
; Fraga, Cléudio N.
; França, Flávio
; Francener, Augusto
; Freitas, Joelcio
; Freitas, Maria F.
; Fritsch, Peter W.
; Furtado, Samyra G.
; Gaglioti, André L.
; Garcia, Flávia C.P.
; Germano Filho, Pedro
; Giacomin, Leandro
; Gil, André S.B.
; Giulietti, Ana M.
; A.P.Godoy, Silvana
; Goldenberg, Renato
; Gomes da Costa, Géssica A.
; Gomes, Mário
; Gomes-Klein, Vera L.
; Gonçalves, Eduardo Gomes
; Graham, Shirley
; Groppo, Milton
; Guedes, Juliana S.
; Guimarães, Leonardo R.S.
; Guimarães, Paulo J.F.
; Guimarães, Elsie F.
; Gutierrez, Raul
; Harley, Raymond
; Hassemer, Gustavo
; Hattori, Eric K.O.
; Hefler, Sonia M.
; Heiden, Gustavo
; Henderson, Andrew
; Hensold, Nancy
; Hiepko, Paul
; Holanda, Ana S.S.
; Iganci, João R.V.
; Imig, Daniela C.
; Indriunas, Alexandre
; Jacques, Eliane L.
; Jardim, Jomar G.
; Kamer, Hiltje M.
; Kameyama, Cíntia
; Kinoshita, Luiza S.
; Kirizawa, Mizué
; Klitgaard, Bente B.
; Koch, Ingrid
; Koschnitzke, Cristiana
; Krauss, Nathália P.
; Kriebel, Ricardo
; Kuntz, Juliana
; Larocca, João
; Leal, Eduardo S.
; Lewis, Gwilym P.
; Lima, Carla T.
; Lima, Haroldo C.
; Lima, Itamar B.
; Lima, Laíce F.G.
; Lima, Laura C.P.
; Lima, Leticia R.
; Lima, Luís F.P.
; Lima, Rita B.
; Lírio, Elton J.
; Liro, Renata M.
; Lleras, Eduardo
; Lobão, Adriana
; Loeuille, Benoit
; Lohmann, Lúcia G.
; Loiola, Maria I.B.
; Lombardi, Julio A.
; Longhi-Wagner, Hilda M.
; Lopes, Rosana C.
; Lorencini, Tiago S.
; Louzada, Rafael B.
; Lovo, Juliana
; Lozano, Eduardo D.
; Lucas, Eve
; Ludtke, Raquel
; Luz, Christian L.
; Maas, Paul
; Machado, Anderson F.P.
; Macias, Leila
; Maciel, Jefferson R.
; Magenta, Mara A.G.
; Mamede, Maria C.H.
; Manoel, Evelin A.
; Marchioretto, Maria S.
; Marques, Juliana S.
; Marquete, Nilda
; Marquete, Ronaldo
; Martinelli, Gustavo
; Martins da Silva, Regina C.V.
; Martins, Ângela B.
; Martins, Erika R.
; Martins, Márcio L.L.
; Martins, Milena V.
; Martins, Renata C.
; Matias, Ligia Q.
; Maya-L., Carlos A.
; Mayo, Simon
; Mazine, Fiorella
; Medeiros, Debora
; Medeiros, Erika S.
; Medeiros, Herison
; Medeiros, João D.
; Meireles, José E.
; Mello-Silva, Renato
; Melo, Aline
; Melo, André L.
; Melo, Efigênia
; Melo, José I.M.
; Menezes, Cristine G.
; Menini Neto, Luiz
; Mentz, Lilian A.
; Mezzonato, A.C.
; Michelangeli, Fabián A.
; Milward-de-Azevedo, Michaele A.
; Miotto, Silvia T.S.
; Miranda, Vitor F.O.
; Mondin, Cláudio A.
; Monge, Marcelo
; Monteiro, Daniele
; Monteiro, Raquel F.
; Moraes, Marta D.
; Moraes, Pedro L.R.
; Mori, Scott A.
; Mota, Aline C.
; Mota, Nara F.O.
; Moura, Tania M.
; Mulgura, Maria
; Nakajima, Jimi N.
; Nardy, Camila
; Nascimento Júnior, José E.
; Noblick, Larry
; Nunes, Teonildes S.
; O'Leary, Nataly
; Oliveira, Arline S.
; Oliveira, Caetano T.
; Oliveira, Juliana A.
; Oliveira, Luciana S.D.
; Oliveira, Maria L.A.A.
; Oliveira, Regina C.
; Oliveira, Renata S.
; Oliveira, Reyjane P.
; Paixão-Souza, Bruno
; Parra, Lara R.
; Pasini, Eduardo
; Pastore, José F.B.
; Pastore, Mayara
; Paula-Souza, Juliana
; Pederneiras, Leandro C.
; Peixoto, Ariane L.
; Pelissari, Gisela
; Pellegrini, Marco O.O.
; Pennington, Toby
; Perdiz, Ricardo O.
; Pereira, Anna C.M.
; Pereira, Maria S.
; Pereira, Rodrigo A.S.
; Pessoa, Clenia
; Pessoa, Edlley M.
; Pessoa, Maria C.R.
; Pinto, Luiz J.S.
; Pinto, Rafael B.
; Pontes, Tiago A.
; Prance, Ghillean T.
; Proença, Carolyn
; Profice, Sheila R.
; Pscheidt, Allan C.
; Queiroz, George A.
; Queiroz, Rubens T.
; Quinet, Alexandre
; Rainer, Heimo
; Ramos, Eliana
; Rando, Juliana G.
; Rapini, Alessandro
; Reginato, Marcelo
; Reis, Ilka P.
; Reis, Priscila A.
; Ribeiro, André R.O.
; Ribeiro, José E.L.S.
; Riina, Ricarda
; Ritter, Mara R.
; Rivadavia, Fernando
; Rocha, Antônio E.S.
; Rocha, Maria J.R.
; Rodrigues, Izabella M.C.
; Rodrigues, Karina F.
; Rodrigues, Rodrigo S.
; Rodrigues, Rodrigo S.
; Rodrigues, Vinícius T.
; Rodrigues, William
; Romaniuc Neto, Sérgio
; Romão, Gerson O.
; Romero, Rosana
; Roque, Nádia
; Rosa, Patrícia
; Rossi, Lúcia
; Sá, Cyl F.C.
; Saavedra, Mariana M.
; Saka, Mariana
; Sakuragui, Cássia M.
; Salas, Roberto M.
; Sales, Margareth F.
; Salimena, Fatima R.G.
; Sampaio, Daniela
; Sancho, Gisela
; Sano, Paulo T.
; Santos, Alessandra
; Santos, Élide P.
; Santos, Juliana S.
; Santos, Marianna R.
; Santos-Gonçalves, Ana P.
; Santos-Silva, Fernanda
; São-Mateus, Wallace
; Saraiva, Deisy P.
; Saridakis, Dennis P.
; Sartori, Ângela L.B.
; Scalon, Viviane R.
; Schneider, Ângelo
; Sebastiani, Renata
; Secco, Ricardo S.
; Senna, Luisa
; Senna-Valle, Luci
; Shirasuna, Regina T.
; Silva Filho, Pedro J.S.
; Silva, Anádria S.
; Silva, Christian
; Silva, Genilson A.R.
; Silva, Gisele O.
; Silva, Márcia C.R.
; Silva, Marcos J.
; Silva, Marcos J.
; Silva, Otávio L.M.
; Silva, Rafaela A.P.
; Silva, Saura R.
; Silva, Tania R.S.
; Silva-Gonçalves, Kelly C.
; Silva-Luz, Cíntia L.
; Simão-Bianchini, Rosângela
; Simões, André O.
; Simpson, Beryl
; Siniscalchi, Carolina M.
; Siqueira Filho, José A.
; Siqueira, Carlos E.
; Siqueira, Josafá C.
; Smith, Nathan P.
; Snak, Cristiane
; Soares Neto, Raimundo L.
; Soares, Kelen P.
; Soares, Marcos V.B.
; Soares, Maria L.
; Soares, Polyana N.
; Sobral, Marcos
; Sodré, Rodolfo C.
; Somner, Genise V.
; Sothers, Cynthia A.
; Sousa, Danilo J.L.
; Souza, Elnatan B.
; Souza, Élvia R.
; Souza, Marcelo
; Souza, Maria L.D.R.
; Souza-Buturi, Fátima O.
; Spina, Andréa P.
; Stapf, María N.S.
; Stefano, Marina V.
; Stehmann, João R.
; Steinmann, Victor
; Takeuchi, Cátia
; Taylor, Charlotte M.
; Taylor, Nigel P.
; Teles, Aristônio M.
; Temponi, Lívia G.
; Terra-Araujo, Mário H.
; Thode, Veronica
; Thomas, W.Wayt
; Tissot-Squalli, Mara L.
; Torke, Benjamin M.
; Torres, Roseli B.
; Tozzi, Ana M.G.A.
; Trad, Rafaela J.
; Trevisan, Rafael
; Trovó, Marcelo
; Valls, José F.M.
; Vaz, Angela M.S.F.
; Versieux, Leonardo
; Viana, Pedro L.
; Vianna Filho, Marcelo D.M.
; Vieira, Ana O.S.
; Vieira, Diego D.
; Vignoli-Silva, Márcia
; Vilar, Thaisa
; Vinhos, Franklin
; Wallnöfer, Bruno
; Wanderley, Maria G.L.
; Wasshausen, Dieter
; Watanabe, Maurício T.C.
; Weigend, Maximilian
; Welker, Cassiano A.D.
; Woodgyer, Elizabeth
; Xifreda, Cecilia C.
; Yamamoto, Kikyo
; Zanin, Ana
; Zenni, Rafael D.
; Zickel, Carmem S
.
Resumo Um levantamento atualizado das plantas com sementes e análises relevantes acerca desta biodiversidade são apresentados. Este trabalho se iniciou em 2010 com a publicação do Catálogo de Plantas e Fungos e, desde então vem sendo atualizado por mais de 430 especialistas trabalhando online. O Brasil abriga atualmente 32.086 espécies nativas de Angiospermas e 23 espécies nativas de Gimnospermas e estes novos dados mostram um aumento de 3% da riqueza em relação a 2010. A Amazônia é o Domínio Fitogeográfico com o maior número de espécies de Gimnospermas, enquanto que a Floresta Atlântica possui a maior riqueza de Angiospermas. Houve um crescimento considerável no número de espécies e nas taxas de endemismo para a maioria dos Domínios (Caatinga, Cerrado, Floresta Atlântica, Pampa e Pantanal), com exceção da Amazônia que apresentou uma diminuição de 2,5% de endemicidade. Entretanto, a maior parte das plantas com sementes que ocorrem no Brasil (57,4%) é endêmica deste território. A proporção de formas de vida varia de acordo com os diferentes Domínios: árvores são mais expressivas na Amazônia e Floresta Atlântica do que nos outros biomas, ervas são dominantes no Pampa e as lianas apresentam riqueza expressiva na Amazônia, Floresta Atlântica e Pantanal. Este trabalho não só quantifica a biodiversidade brasileira, mas também indica as lacunas de conhecimento e o desafio a ser enfrentado para a conservação desta flora.
Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora.
https://doi.org/10.1590/2175-7860201566411
33340 downloads
9.
Performance evaluation of commercial copper chromites as burning rate catalyst for solid propellants
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Campos, Eunice Aparecida
; Dutra, Rita de Cássia L.
; Rezende, Luis Cláudio
; Diniz, Milton Faria
; Nawa, Wilma Massae Dio
; Iha, Koshun
.
Journal of Aerospace Technology and Management
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Abstract: Copper chromites are well known as burning rate catalysts for the combustion of composite solid propellants, used as a source of energy for rocket propulsion. The propellant burning rate depends upon the catalyst characteristics such as chemical composition and specific surface area. In this work, copper chromite samples from different suppliers were characterized by chemical analysis, FT-IR spectroscopy and by surface area measurement (BET). The samples were then evaluated as burning rate catalyst in a typical composite propellant formulation based on HTPB binder, ammonium perchlorate and aluminum. The obtained surface area values are very close to those informed by the catalyst suppliers. The propellant processing as well as its mechanical properties were not substantially affected by the type of catalyst. Some copper chromite catalysts caused an increase in the propellant burning rate in comparison to the iron oxide catalyst. The results show that in addition to the surface area, other parameters like chemical composition, crystalline structure and the presence of impurities might be affecting the catalyst performance. All evaluated copper chromite samples may be used as burning rate catalyst in composite solid propellant formulations, with slight advantages for the SX14, Cu-0202P and Cu-1800P samples, which led to the highest burning rate propellants.
https://doi.org/10.5028/jatm.2010.02038010
980 downloads
10.
Study of the termal decomposition of 2,2',4,4',6,6'- hexanitrostilbene
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Silva, Gilson da
; Iha, Koshum
; Cardoso, Andreza M.
; Mattos, Elizabeth C.
; Dutra, Rita de Cássia L.
.
Journal of Aerospace Technology and Management
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Abstract: 2,2’, 4,4’, 6,6’- hexanitrostilbene (HNS) is an energetic material, a nitroaromatic compound, with thermal and chemical stabilities, which is employed in the aerospace industry. In this work, the Arrhenius parameters (activation energy and pre-exponential factor) of thermal decomposition reaction were studied and the results were compared with the values reported in the literature. The Kissinger method, applied to DSC’s nonisothermal data of the decomposition temperature was chosen for this study. The activation energy determined for the thermal decomposition of HNS revealed values from 428 kJ.mol-1 to 477 kJ.mol-1, under the experimental conditions employed.
https://doi.org/10.5028/jatm.2010.02014146
505 downloads
11.
Síntese e caracterização por espectroscopia no infravermelho de agente de ligação à base de hidantoína, utilizado em propelentes compósitos
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Pires, Darci C.
; Stockler-Pinto, Denise V. B.
; Sciamareli, Jairo
; Costa, Jorge Roberto da
; Diniz, Milton Faria
; Iha, Koshun
; Dutra, Rita de Cássia L.
.
Journal of Aerospace Technology and Management
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Resumo: Reações para obtenção de derivados de hidantoína foram conduzidas a partir de aldeídos de cadeia curta e da 5,5-dimetilhidantoína. O acompanhamento das reações foi realizado por espectroscopia na região do infravermelho médio (MIR) por meio da formação de novas bandas características da estrutura do composto desejado. A análise MIR revelou que estas alterações espectrométricas ocorrem somente na reação com o formaldeído, indicando a formação do produto 1,3-bis(hidroximetil)-5,5-dimetilhidantoína, em presença de água. As bandas de absorção que confirmam a reação foram observadas em 3334 cm-1 (υ OH), 1770 e 1710 cm-1 (υ C=O) e em 1056 cm-1 (υ C-O), sendo esta última, atribuída ao grupo contendo hidroxila primária. A reação da 5,5-dimetil hidantoína com acetaldeído e com propanaldeído não ocorreu sob as condições adotadas neste trabalho.
Abstract: Reactions to obtain hydantoin derivatives were carried out with 5,5-dimethylhydantoin and short-chain aldehydes. Monitoring of the reactions was performed using qualitative mid-infrared spectroscopy (MIR) through the formation of new bands characteristic of the desired product. MIR analysis showed that these spectrometric alterations occur only in the reaction with the formaldehyde, indicating the formation of the desired product, 1,3-bis (hydroxymethyl) 5,5-dimethylhydantoin, in the presence of water. The absorption bands that confirmed the reaction were observed at 3334 cm-1 (υ OH), 1770 and 1710 cm-1 (υ C=O) and 1056 cm-1 (υ C-O), the last of which is assigned to the group containing primary hydroxyl.
https://doi.org/10.5028/jatm.2009.0102177184
1434 downloads
12.
ADN - The new oxidizer around the corner for an environmentally friendly smokeless propellant
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Nagamachi, Márcio Y.
; Oliveira, José Irineu S.
; Kawamoto, Aparecida M.
; Dutra, Rita de Cássia L.
.
Journal of Aerospace Technology and Management
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Abstract: The search for a smokeless propellant has encouraged scientists and engineers to look for a chlorine-free oxidizer as a substitute for AP (ammonium perchlorate). Endeavors seemed to come to an end when ADN (ammonium dinitramide) appeared in the West in the early 1990s. Although some drawbacks soon became apparent by that time, the foremost obstacle for its use in rocket-motors came from the patent originally applied for in the United States in 1990. Furthermore, environmental concerns have also increased during these two decades. Ammonium perchlorate is believed to cause thyroid cancer by contaminating soil and water. In addition, AP produces hydrogen chloride during burning which can cause acid rain and ozone layer depletion. Unlike AP, ADN stands for both smokeless and green propellant. Since then, much progress has been made in its development in synthesis, re-shaping, microencapsulation and solid propellant. The high solubility of ADN in water has also allowed its application as liquid monopropellant. Tests have revealed Isp (specific impulse) superior to that normally observed with hydrazine, one of the most harmful and hazardous liquid propellants. With constraints of use, along with the patent near to expiry, scientists and engineers are rushing to complete developments and patents until then.
https://doi.org/10.5028/jatm.2009.0102153160
1268 downloads
13.
Determination of polymer content in energetic materials by FT-IR
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Journal of Aerospace Technology and Management
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Abstract: A new methodology was developed to characterize and to quantify the polymer content in PBX (HMX/Viton) by Fourier Transform Infrared Spectroscopy (FT-IR), using the Termogravimetric analysis (TG) as reference techniques for the quantitative method. The quantification methodology, proposed by us, using the Fourier transform infrared-attenuated total reflectance (FT-IR/ATR) showed excellent results, being faster than the usual methodologies and can eliminate the generation of chemical residues.
https://doi.org/10.5028/jatm.2009.0102167175
691 downloads
14.
Synthesis and characterization of energetic thermoplastic elastomers for propellant formulations
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Kawamoto, Aparecida M.
; Oliveira, José Irineu S.
; Dutra, Rita de Cássia L.
; Rezende, Luis Cláudio
; Keicher, Thomas
; Krause, Horst
.
Journal of Aerospace Technology and Management
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Abstract: Synthesis and characterization of energetic ABA-type thermoplastic elastomers for propellant formulations has been carried out. Following the working plan elaborated, the synthesis and characterization of Poly 3-bromomethyl-3-methyl oxetane (PolyBrMMO), Poly 3- azidomethyl-3-methyl oxetane (PolyAMMO), Poly 3,3-bis-azidomethyl oxetane (PolyBAMO) and Copolymer PolyBAMO/AMMO (by TDI end capping) has been successfully performed. The thermoplastic elastomers (TPEs) were synthesized using the chain elongation process PolyAMMO, GAP and PolyBAMO by diisocyanates. In this method 2.4-toluene diisocyanate (TDI) is used to link block A (hardandmono-functional)) to B (soft and di-functional). For the hard A-block we used PolyBAMO and for the soft B-block we used PolyAMMO or GAP. This is ajoint project set up, someyears ago, between the Chemistry Division of the Institute of Aeronautics and Space (IAE) - subordinated to the Brazilian Ministry of Defense - and the Fraunhofer Institut Chemische Technologie (ICT), in Germany. The products were characterized by different techniques as IR- and (1H, 13C) NMR spectroscopies, elemental and thermal analyses. New methodologies based on FT-IR analysis have been developed as an alternative for the determination of the molecular weight and CHNO content of the energetic polymers.
https://doi.org/10.5028/jatm.2009.01013542
945 downloads
15.
Avaliação de agente de ligação aziridínico por meio de técnicas de análise química e instrumental
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Pires, Darci Cortes
; Kawamoto, Aparecida M.
; Sciamareli, Jairo
; Mattos, Elizabeth E.
; Diniz, Milton F.
; Dutra, Rita de Cássia L.
; lha, Koshun
.
Journal of Aerospace Technology and Management
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Resumo: Um novo método de análise por via úmida e instrumental foi desenvolvido para avaliação da abertura do anel aziridínico do óxido de tris(l-(2-metil)aziridinil) fosfina (MAPO), agente de ligação usado em propelente compósito. Foi observada redução de intensidade das bandas de absorção em 1400 e 1040 cm-1, que são características do anel aziridínico. Em alguns casos, observou-se que, quando o número de anéis abertos aumenta, a banda de absorção do grupo NH, na região 3400 e 3300 cm-1, que aparece com a abertura do anel, está localizada na região de menor número de onda. O estudo de síntese do derivado do MAPO evidenciou reações secundárias com a hidroxila do ácido 12-hidroxiesteárico, homopolimerização e reação com a umidade existente na amostra.
Abstract: A new method using wet chemistry and instrumental analysis has been developed for evaluating the ring-opening of aziridine tris [l-(2 methyl) aziridinyl] phosphide oxide (MAPO) of the bonding agent used in composite propellant. A reduction was observed in the intensity absorption bands in 1400 and 1040 cm-1, characteristic of aziridinic ring. It was also observed, in some cases, that when the number of open aziridinyl ring increases, the NH band in the range 3400-3300 cm-1, that appears with ring-opening, is located in the region of lower wave numbers. The study of the synthesis of MAPO derivative indicated side reactions such as homopolymerization of rings and also, with secondary hydroxyl of the 12-hydroxy stearic acid and probable humidity existent in the original sample.
https://doi.org/10.5028/jatm.2009.01015561
475 downloads
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