Pedro Nicó de Medeiros Neto

Eficiência dos óleos de nim e mamona contra cupins xilófagos em ensaio de alimentação forçada

The research aimed to evaluate the efficiency of neem (Azadirachta indica) and castor oil plant (Ricinus communis) oils to improvement of Ceiba pentandra wood resistance to Nasutitermes corniger xilophogous termite under forced food assay. The neem and castor oil plant oils were extracted with absolute ethyl alcohol and employees in the preparation of oil solutions. Wood samples with dimensions of 2.0 x 2.54 x 0.64 cm (radial x longitudinal x tangential) were treated to reach a nominal retention of 10 to 16 kg of solution/m3 of wood. A part of treated samples was submitted to the weathering test (volatily and leaching tests). The treated samples were submitted to termite action under forced food assay. The neem and castor oil plant oils, on employed retention, did not contribute to improvement of Ceiba pentandra wood resistance to xylophogous termites. Among the tested solutions, the pure castor oil plant oil was more efficient. The weathering test of samples did not influence the wood resistance. The neem and of pure castor oil plant oils and their solutions, even presenting some repulsive effect to termites, their effect are not durable, indicating that they should not be used in wood treatment in order to improve its resistance to xylophogous termites.

Relações entre as Características da Madeira e do Carvão Vegetal de duas Espécies da Caatinga / Relationship between the Characteristics of Wood and Charcoal of two Caatinga Tree Species

The Caatinga vegetation is explored for energy, but there are few studies on the relationship between of the characteristics of wood and its energy potential. Therefore, this study aimed to relate the characteristics of wood and charcoal of Poincianella pyramidalis and Handroanthus impetiginosus species. To this end, five trees of each species were felled, and parts of 30 cm in length were removed at 0 (base), 25, 50, 75 and 100% of the commercial height of the trees. This material was used for determination of the characteristics of wood and charcoal. P. pyramidalis produced greater yield of charcoal compared with H. impetiginosus; however, the wood of the latter species presented better characteristics for energy purposes. The two species showed different relations between anatomical, physicochemical and energy characteristics. The knowledge about the disparity between the relations of the wood characteristics enables its most adequate use for energy purposes.

Eficiência dos óleos de nim (Azadirachta indica) e de mamona (Ricinus communis) na proteção da madeira de sumaúma (Ceiba pentandra)contra cupins xilófagos em ensaio de preferência alimentar

The objective of this work was to evaluate the efficiency of oils from neem (Azadirachta indica) and castor plant (Ricinus communis) in improving the resistance of Sumauma wood (Ceiba pentandra) to Nasutitermes corniger xylophogous termite under feed preference assay. Oils from neem and castor oil plant were extracted with absolute ethyl alcohol and used in preparing preservative solutions. Wood samples with dimensions of 2.0 × 10.16 × 0.64 cm (radial × longitudinal × tangential) were treated to reach a nominal retention of 10 to 16 kg of solution by m 3 of wood, and some treated samples were submitted to the weathering test (volatily and leaching tests). The treated samples were submitted to termites in feed preference assay. Oils from neem and castor oil plant did not contribute much to improvement of Sumauma wood resistance to the tested termite. Among the tested solutions, the pure castor oil plant oil was the most efficient. Weathering of samples little influenced wood resistance. Although neem and pure castor oil plant oils presented some repulsive effect to termites, their effects are not durable, indicating that these products should not be used in wood treatment in order to improve its resistance to xylophogous termites.

Physico-chemical and energetic evaluation of wood from the species Piptadenia stipulacea (Benth.) Ducke and Amburana cearensis (Allemao) A. C. Smith in a semi-arid region in northeast Brazil.

‘Caatinga’ is an exclusive Brazilian biome, which features a wide variety of fauna and flora, and a good part of these are endemic varieties. Over the years, the abolition of ‘Caatinga’ by human activities has greatly reduced this biome. This fact is mainly due to the use of the energy potential of plant species without proper concern about the sustainability of it. A better understanding of the energy potential of plant species of ‘Caatinga’ enables a more appropriate management. The objective of this study was to evaluate the potential energy and the physical and chemical characteristics of wood species Amburana cearensis (Germans) A. C. Smith and Piptadenia stipulacea (Benth.) Ducke. Five trees of each species were felled, randomly sampled in ‘Sao Bento’ site, located in the city of Patos, Paraiba state. The trees were identified and transported to the Department of Forest Product Technology, Federal University of Campina Grande. From each tree, small discs were removed (5 cm thick) to 0 (base), 25, 50, 75 and 100% of the commercial height of the trunk (up to 5 cm in diameter) and large disks (15 cm thick) before and after each small disk, the small discs were divided into four parts, wedge-shaped, passing through the medulla. Two opposing wedges were used to determine the density and the rest was reserved for the physical and chemical wood analyses and the wood discs were destined for greater achievements of carbonizations. Basic density was determined according to the method of hydrostatic balance and to determine the basic density of each tree used as a weighting factor the volume between sections of each disk. After air drying, the samples for chemical analysis were transformed into sawdust and made quantitative determinations of total extractives, lignin, ash and holocellulose content was estimated by difference from the initial mass [100% (content total extractives + lignin + ash)]. Samples intended for carbonizations were transformed into chips, and charred in an electric furnace (furnace) for 5 hours and 30 minutes. The income from the carbonization products as well as the physical and chemical properties of charcoal were determined. Averages significantly higher than 1% probability of lignin, holocellulose content, total extractives and ash wood were found for the species Amburana cearensis and Piptadenia stipulacea, and this latter had higher average lignin content and holocellulose content. The gravimetric yield was similar for both species, while the condensed liquid yield was significantly higher for Amburana cearensis. In relation to coal quality, higher values were observed for gross calorific value and fixed carbon for Piptadenia stipulacea, while Amburana cearensis exhibited higher levels of volatiles and ash.