Nuclear Reactions
Mostrando 25-36 de 382 artigos, teses e dissertações.
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25. Synthesis and Characterization of New Diazenecarboxamide Ligands Using a Selective Adduct Formation with B(C6F5)3
The synthesis and structure of new N-(2,6-diisopropylphenyl)-2-phenyldiazenecarboxamide (L2) and N-(2,6-diisopropylphenyl)-2 (perfluorophenyl) diazenecarboxamide (L3) ligands are described. The subsequent reactions of ligands L1, L2 and L3 with trispentafluorophenylboron gave rise to new adducts (A1), (A2) and (A3), where B(C6F5)3 is coordinated to the carbo
J. Braz. Chem. Soc.. Publicado em: 2016-01
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26. PRODUÇÃO DE BIODIESEL A PARTIR DE ÁCIDOS GRAXOS PROVENIENTES DO REFINO DE ÓLEOS VEGETAIS VIA CATÁLISE ÁCIDA HETEROGENEA E MICRO-ONDAS
This work presents the biofuel production results of the esterification of fatty acids (C12-C18) and high-acid-content waste vegetable oils from different soap stocks (soybean, palm, and coconut) with methanol, ethanol, and butanol by acid catalysis. We used Amberlyst-35 (A35) sulfonic resin as a heterogeneous acid catalyst and p-toluenesulfonic acid as a ho
Quím. Nova. Publicado em: 2015-12
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27. Biodegradable Copolymers Obtained by Solution Polymerization
This study aims the synthesis of copolymers of poly (l-lactic acid) and polycaprolactone by ring opening polymerization. The reactions between l-lactide (LLA) and ε-caprolactone (CL) monomers, in 100/0, 95/5, 90/10 and 80/20 LLA/CL mass ratios, were conducted in refluxing toluene, using Stannous octoate as iniciator, methanol as co-iniciator and inert atmos
Mat. Res.. Publicado em: 23/10/2015
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28. Synthesis of Triacetin and Evaluation on Motor
Triacetin (or glycerol triacetate) was obtained by acetylating the glycerol by-product of biodiesel production process. This procedure is an interesting alternative that follows the principles of green chemistry. In this work, triacetin was synthesized using reactions between glycerol and acetic acid, as well as glycerol and acetic anhydride, using homoge
J. Braz. Chem. Soc.. Publicado em: 2015-08
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29. Multiple Dynamics of Hydrazone Based Compounds
Hydrazone derivatives of 2-quinolinecarboxaldehyde and 6-bromo-2-pyridinecarboxaldehyde were synthesized by sequence reactions with hydrazine derivatives. These compounds exhibited E/Z isomerization upon irradiation using a mercury lamp (250 W). The configurational changes were monitored by 1H nuclear magnetic resonance (NMR), UV-Vis and fluorescence spectro
J. Braz. Chem. Soc.. Publicado em: 2015-06
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30. Cellulose Sulfuric Acid as an Eco-Friendly Catalyst for Novel Synthesis of Pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5-ones
A novel synthesis of a series of pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5-ones has been developed from reactions of 1-(5-methyl-1-phenyl-1H-pyrazol-4-yl)-3-arylprop-2-en-1-ones and 7-amino-1,3-disubstituted[1,2,4]triazolo[4,3-a]pyrimidin-5(1H)-ones in dioxane under thermal conditions, using cellulose sulfuric acid as an eco-friendly acid catalyst. The
J. Braz. Chem. Soc.. Publicado em: 2015-05
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31. Kinetic Investigation of Thermal Formation Processes of SiOC Glasses Derived from C-Containing Hybrid Polymeric Networks
In this study, hybrid polymeric networks were prepared by hydrosilylation reaction as precursors to silicon oxycarbide (SiOC) glass. The polymeric networks were prepared from poly(methylsiloxane) (PMS) and divinylbenzene (DVB) in the 80:20 and 20:80 (PMS/DVB) compositions, with or without activated charcoal (AC), which was used as additional carbon source. F
J. Braz. Chem. Soc.. Publicado em: 2015-05
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32. Glicólise do poli(3-hidroxibutirato) por via enzimática
Poly(3-hydroxybutyrate), PHB, is a polymer with broad potential applications because of its biodegradability and biocompatibility. However, its high crystallinity is a limiting factor for many applications. To overcome this drawback, one strategy currently employed involves the reduction of the molecular weight of PHB with the concomitant formation of end-fu
Quím. Nova. Publicado em: 2014-06
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33. Study of biodiesel photodegradation through reactions catalyzed by Fenton's reagent
A fotodegradação de biodiesel em contato com água, utilizando reação foto-Fenton, foi investigada neste estudo. Após 360 h de fotodegradação obteve-se uma redução de 73% dos ésteres metílicos de ácidos graxos (FAMEs) quantificados inicialmente por cromatografia em fase gasosa acoplada ao detector por ionização em chama (GC/FID). No decorrer da
J. Braz. Chem. Soc.. Publicado em: 2014-04
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34. Inorganic-organic hybrids originating from organosilane anchored onto leached vermiculite
The reactivity of clay minerals leached in grafting reactions was investigated. Precursor solids were prepared by treating the sodium vermiculites with nitric acid solutions at several concentrations. The lixiviation produced the restructured porous solids with surface area over a wide range, varying from 133 to 673 m² g- 1. The sodium and lixiviated vermic
Mat. Res.. Publicado em: 21/05/2013
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35. ReaÃÃes biocatalÃticas usando cÃlulas Ãntegras de Lens culinaris (Lentilha). / REACTIONS USING WHOLE CELL BIOCATALYTIC LENS CULINARIS (LENTIL)
This paper describes the use of seeds of lentil (Lens culinaris) as intact plant system in biocatalytic reactions of reduction and hydrolysis. Initially, some plant sources were evaluated for their action in the biocatalytic reduction of aromatic ketone acetophenone. The plants that showed positive results in the reduction reaction underwent determination of
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/10/2012
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36. Estudo de proteínas relacionadas ao costâmero em secções longitudinais de músculo sóleo de ratas imobilizadas e reabilitadas pelo alongamento passivo manual intermitente / Study of costameric proteins in soleus muscle longitudinal sections of female rats immobilized and rehabilitated by intermittent passive manual stretching
The interface between sarcolemma and extracellular matrix in skeletal muscle tissue is constituted by specialized proteins that are responsible for the transversal and longitudinal forces transmission to the myofiber. Skeletal muscle adaptations to physiological and pathological forces, such as segmental immobilization and rehabilitation exercises, may contr
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/06/2012