Two insect colonies of Elasmopalpus lignosellus were reared in our laboratory, the first being initiated from pupae obtained from a cornfield in the region of Sete Lagoas, Minas Gerais and the second from a cornfield in the region of Goiânia, Goiás. From the two colonies, two extracts were prepared from the pheromone glands of virgin E. lignosellus females. The extract obtained from the first colony was designated as extract 1 while the extract obtained from the second colony was designated as extract 2. Extract 1 was analyzed by gas chromatography-mass spectrometry (GC-MS) with (Z)-9-hexadecenyl acetate [(Z)-9-HDA] and (Z)-11-hexadecenyl acetate [(Z)-11-HDA] being identified and confirmed by the formation of DMDS derivatives. In addition, a third acetate, which could be either (E)-8-hexadecenyl acetate [(E)-8-HDA] or (E)-9-hexadecenyl acetate [(E)-9-HDA] was detected by GC-MS. Extract 2 was analyzed by gas chromatography (GC) and gas chromatography-electroannetography (GC-EAD) revealing the presence of (Z)-11-HDA and (Z)-9-TDA. In addition, the same compounds elicited a response with the E. lignosellus male antenna obtained from the second insect colony. Electroantennography (EAG) screening with the male E. lignosellus antenna (obtained from the second insect colony) was conducted with the 23 possible tetradecenyl acetates (TDA) and 22 hexadecenyl acetates (HDA) as standards. Out of the 23 TDA isomers evaluated, only (Z)-9-TDA elicited a response and out of the 22 HDA [(Z) and (E) isomers gamma2 to delta13] evaluated only (Z)-11-HDA elicited a response. The acetate compositions of two extracts obtained from insects originating from the two states (Minas Gerais and Goiás) of Brazil were different from one another as well as from that obtained from insects in Tifton, GA, USA. The bioactivity data (GC-EAD) of the extract 2 differed from those reported for the Tifton, GA, USA population. These data suggest polymorphism in relation to the insect populations found in Brazil and in the USA. The possibility of the existence of an E. lignosellus sub-species cannot be ruled out.
Recebido em 7/6/06; aceito em 6/9/06; publicado na web em 26/3/07Based on a specially created mass spectral database utilizing 23 tetradecenyl and 22 hexadecenyl acetate standards along with Kóvats retention indices obtained on a very polar stationary phase [poly (biscyanopropyl siloxane)] (SP 2340), (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl acetate and (E)-8-hexadecenyl acetate were identified in active pheromone extracts of Elasmopalpus lignosellus. This identification was more efficient than our previous study using gas chromatography/mass spectrometry with a dimethyl disulfide derivative where we could only identify the first two acetates. The acetate composition of the pheromone gland differed from region to region in Brazil and from that from the Tifton (GA, USA) population, suggesting polymorphism or a different sub-species.
Organic derivatives of boron, such as boronic esters and acids, are important precursors for a wide range of environmental, energy, and health applications. Several catalytic methods for their synthesis have been reported, even though with the use of toxic and structurally complex ligands. Herein, we demonstrate preliminary studies envisaging the synthesis of boronic esters from an inexpensive catalytic system based on Cu/Al layered double hydroxides (LDH) in the presence of Na2PdCl4. The Cu/ Al LDHs were prepared according to coprecipitation method and characterized by X-ray diffraction (XRD) (with Rietveld refinement) to evaluate the contamination with malachite and other phases. Preliminary catalytic results suggest that pure Cu/Al LDH has potential for the borylation of aryl iodides/ bromides in the absence of base. Indeed, a synergic effect between copper and palladium is possibly related to the catalytic efficiency.
WELLS. The growing global concern about the environment associated with academic and government efforts are enabling a number of alternatives for sustainable development. Within this perspective one can include the search for value-added products using waste from renewable energy sources, such as those from the production of biodiesel. The rapid development of biodiesel production in Brazil directly affected the supply of glycerin and therefore the sector is seeking a market that can absorb this waste. Thus, with the increasing search for environmentally friendly products, formulation of a drilling fluid using a co-product of biodiesel production to replace the n-paraffin is of great importance to the oil industry for meeting the requirement of environmental regulation and, in addition, considerably reducing the cost of raw materials. In this context, the aim of this study was to characterize different glycerins to evaluate their potential as basis for drilling fluids for oil wells and gas. The glycerins were stable under the conditions evaluated without phase separation and precipitation of solids, exhibited good rheological profile and low value of interface tension. The results indicate a strong possibility of use of these glycerins as basis for drilling fluids and applicability by the oil industry.Keywords: glycerin; drilling fluids; petroleum industry. INTRODUÇÃOFluidos de perfuração para poços de petróleo e gás são dispersões complexas de sólidos, líquidos e/ou gases, usualmente constituídas de uma fase dispersante ou base (aquosa ou orgânica) e outra dispersa, cuja complexidade depende da natureza dos produtos dispersos, dos requisitos e das funções necessárias para operação de perfuração, tais como manutenção da integridade da parede do poço, remoção dos cascalhos gerados durante o processo de perfuração, resfriamento e lubrificação da coluna de perfuração e da broca. 1 Dependendo da composição de sua fase dispersante, os fluidos de perfuração podem ser à base de água (Water-Based Drilling Fluids -WBDF), à base de gás (Gas-Based Drilling Fluids -GBDF) e à base de óleo (Oil-Based Drilling Fluids -OBDF), que inclui fluidos de base oleosa sintética (Synthetic-Oil-Based Drilling Fluids -SOBDF).Desde o início da utilização de fluidos de perfuração, quando se utilizava a água para auxiliar as ferramentas na construção dos poços de água subterrânea, seu desenvolvimento permanece até hoje como um grande desafio para a indústria do petróleo, na busca por um fluido que seja de baixo custo, de fácil manipulação, com propriedades técnicas adequadas e ambientalmente correto. 2 A indústria do petróleo investe permanentemente em pesquisa e desenvolvimento de novas tecnologias, tanto em produtos (aditivos) quanto em novas bases para sistemas de fluidos de perfuração, especialmente no Brasil, à medida que os poços de petróleo e gás se tornam mais profundos e novos cenários mais complexos vão surgindo, tais como os poços de petróleo perfurados no cenário do pré-sal e poços com geometria complexa envolvendo trechos de alta...
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