Halogens
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. Design, Synthesis and Antifungal Activity of New Schiff Bases Bearing 2-Aminothiophene Derivatives Obtained by Molecular Simplification
Seventeen Schiff bases bearing 2-aminothiophene derivatives were designed and synthesized using molecular simplification. The resulting compounds (4a-4q) were evaluated for their in vitro antifungal activity against dermatophytes. Prediction of their druglikeness and pharmacokinetic properties, establishment of their structure-activity relationships (SAR), a
J. Braz. Chem. Soc.. Publicado em: 2021-05
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2. UMA RELEITURA DOS ARTIGOS CIENTÍFICOS DO PROF. HANS STAMMREICH
In this work we provide a revision of the studies by Raman spectroscopy carried out by Prof. Hans Stammreich in the São Paulo University. The works of Prof. Stammreich are discussed focusing on the most important conclusion of each paper and the scientific issue at the time of publication. Approximately twenty-five papers are discussed, which were separated
Quím. Nova. Publicado em: 05/12/2019
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3. Halogen Determination in Polymeric Waste of Electrical and Electronic Equipment: Overcoming Limitations in Sample Preparation
Sample preparation of polymers for halogen determination requires special attention because they are difficult to bring into solution and due to the risk of analyte losses when using acid digestion. A method using microwave-induced combustion (MIC) was optimized for accurate determination of halogens in polymeric parts obtained in waste of electrical and ele
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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4. Synthesis and biological evaluation of novel imidazolidine derivatives as candidates to schistosomicidal agents
ABSTRACT Introduction: Schistosomiasis is an infectious parasitic disease caused by trematodes of the genus Schistosoma, which threatens at least 258 million people worldwide and its control is dependent on a single drug, praziquantel. The aim of this study was to evaluate the anti-Schistosoma mansoni activity in vitro of novel imidazolidine derivatives.
Rev. Inst. Med. trop. S. Paulo. Publicado em: 03/04/2017
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5. Avaliação de métodos de preparo de amostra para a determinação de halogênios em alumina de alta pureza / Evaluation of sample preparation methods for halogens determination in high-purity alumina
The presence of trace elements in high purity alumina (e.g. halogens) can compromise the final product characteristics. In this work, different sample preparation methods based on alkaline fusion, halogen extraction in water with and without microwave heating, alkaline extraction, microwave-induced combustion and pyrohydrolysis for further halogens determina
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/04/2011
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6. O plÃsmon da regiÃo de recobrimento da ligaÃÃo quÃmica como ferramenta para caracterizaÃÃo de materiais
Important issues can be raised about the possibility of relations between macroscopic properties of materials and concepts, introduced recently, of the chemical bond overlap polarizability (PR) and the concept of ionic specific valence (VIE). A proposal in which the overlap region of chemical bond is considered as a âplasmon‐likeâ charge distribution
Publicado em: 2009
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7. AdsorÃÃo de Ãtomos alcalinos e halogÃnios em uma superfÃcie de Grafeno: um estudo de primeiros princÃpios. / Adsorption of alkaline and alogen atoms on a graphene surface: a frist principle studie
O grafeno à atualmente o tÃpico mais corrente em fÃsica da materia condensada e ciÃncia dos materiais e foi isolado pela primeira vez a menos de quatro anos. O grafeno tem sido proposto como um material alternativo aos nanotubos de carbono em diversas aplicaÃÃes, devido a sua fÃcil sintetizaÃÃo e seu baixo custo. A fim de explorar uma potencial apli
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/02/2008
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8. A tabela periódica dos elementos químicos prevista por redes neurais artificiais de Kohonen
Although several chemical elements were not known by end of the 18th century, Mendeleyev came up with an astonishing achievement: the periodic table of elements. He was not only able to predict the existence of (then) new elements but also to provide accurate estimates of their chemical and physical properties. This is certainly a relevant example of the hum
Química Nova. Publicado em: 2008
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9. Application of peracetic acid in the eucalyptus pulp bleaching and its quality impact / Aplicação do ácido peracético no branqueamento da polpa de eucalipto e o impacto na sua qualidade
In the productive sector of cellulose the demands on the quality of the final product are too great, once the market is very competitive and globalized. The main objectives of this paper were the establishment of appropriate conditions to implement the peracetic acid as the last stage of elemental chlorine-free (ECF) bleaching sequence and assessing the impa
Publicado em: 2008
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10. DETERMINATION OF HALOGENS IN COAL, PETROLEUM COKE AND FOOD AFTER MICROWAVE INDUCED COMBUSTION / DETERMINAÇÃO DE HALOGÊNIOS EM CARVÃO, COQUE PETROQUÍMICO E ALIMENTOS APÓS COMBUSTÃO INICIADA POR MICROONDAS
O método de combustão iniciada por microondas (MIC) foi aplicado para a decomposição de carvão e coque de petróleo para posterior determinação de Br, Cl, F e I por cromatografia de íons (IC). Foram decompostas até 500 mg de amostra usando 20 bar de oxigênio e os analitos foram absorvidos em água ou soluções de 10 a 50 mmol l-1 de (NH4)2CO3. Uma
Publicado em: 2008
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11. Metil coenzima M redutase (MCR) e o fator 430 (F430)
This review presents studies on methyl coenzyme M reductase, the biological system Factor 430 (F430) and the use of nickel(II) complexes as structural and functional models. The ability of F430 and nickel(II) macrocycle complexes to mediate the reductive dehalogenation of cyclohexyl halogens and the CH3-S bond cleavage of methyl CoM (by sodium borohydride an
Química Nova. Publicado em: 2006-10
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12. Comparison of diamond growth with different gas mixtures in microwave plasma asssited chemical vapor deposition (MWCVD)
In this work we study the influence of oxygen addition to several halocarbon-hydrogen gas systems. Diamond growth have been performed in a high power density MWCVD reactor built in our laboratory. The growth experiments are monitored by argon actinometry as a reference to plasma temperature and atomic hydrogen production, and by mass spectrometry to compare
Materials Research. Publicado em: 2003-01