Thermoanalytical study and characterization of native starches of Paraná pine seeds (Araucaria angustiofolia, Bert O. Ktze) and European chestnut seeds (Castanea sativa, Mill)

Starch is the most important carbohydrate storage in plants. It is a raw material with diverse botanical origins, and is used by the food, paper, chemical, pharmaceutical, textile and other industries. In this work, native starches of Paraná pine seeds (pinhão) (Araucária angustiofolia, Bert O. Ktze) and european chestnut seeds (Castanea sativa, Mill) were studied by thermoanalytical techniques: thermo-gravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), as well as X-ray powder patterns diffractometry. Apparent and total amylose content was also determined.

Adsorption isotherm studies of BOD, TSS and colour reduction from palm oil mill effluent (POME) using boiler fly ash

Palm oil is one of the two most important vegetable oils in the world's oil and fats market. The extraction and purification processes generate different kinds of waste generally known as palm oil mill effluent (POME). Earlier studies had indicated the possibility of using boiler fly ash to adsorb impurities and colour in POME treatment. The adsorption treatment of POME using boiler fly ash was further investigated in detail in this work with regards to the reduction of BOD, colour and TSS from palm oil mill effluent. The amount of BOD, colour and TSS adsorbed increased as the weight of the boiler fly ash used was increased. Also, the smaller particle size of 425µm adsorbed more than the 850µm size. Attempts were made to fit the experimental data with the Freundlich, Langmuir and Dubinin-Radushkevich isotherms. The R² values, which ranged from 0.8974-0.9898, 0.8848-0.9824 and 0.6235-0.9101 for Freundlich, Langmuir and Dubinin-Radushkevich isotherms respectively, showed that Freundlich isotherm gave a better fit followed by Langmuir and then Dubinin-Radushkevich isotherm. The sorption trend could be put as BOD > Colour > TSS. The apparent energy of adsorption was found to be 1.25, 0.58 and 0.97 (KJ/mol) for BOD, colour and TSS respectively, showing that sorption process occurs by physiosorption. Therefore, boiler fly ash is capable of reducing BOD, Colour and TSS from POME and hence could be used to develop a good adsorbent for POME treatment.

Química e colorimetria da madeira de Eucalyptus grandis W. Mill ex Maiden termorretificada

A termorretificação visa melhorar as características para agregar valor à madeira através da aplicação de calor. O objetivo foi avaliar as alterações químicas e colorimétricas da madeira termorretificada de Eucalyptus grandis submetida a 170, 200 e 230 ºC por 3, 5 e 7 h. Os teores de extrativos, lignina, holocelulose, composição elementar e os parâmetros colorimétricos foram determinados. Os teores de extrativos aumentaram nos tratamentos a 170 °C e diminuíram a partir de 200 °C, enquanto o teor de lignina total aumentou e o de holocelulose diminuiu a partir de 200 °C. O teor de carbono aumentou e o de oxigênio diminuiu a 230 °C por 5 e 7 h. A termorretificação reduziu a claridade, matriz vermelho (a*) e matriz amarelo (b*) da madeira de eucalipto em todos os tratamentos.

EFFECTS OF HARVESTING ON LEAF PRODUCTION AND REPRODUCTIVE PERFORMANCE OF Copernicia prunifera (Mill.) H.E. Moore1

ABSTRACT This work aimed to evaluate the consequences of the monthly extraction of immature leaves in survival, leaf production and reproductive performance ofCopernicia prunifera H. E. Moore palm, popularly known as carnaúba. One hundred sixty reproductive adult palms were monitored for 17 months in four extractive communities located at the coast of the state of Piauí. As a result, it was observed that leaves, flowers, fruits and seeds production were reduced in the palm submitted to 50% or 75% monthly extraction. Higher levels of extraction were followed by smaller levels in seed germination. No deaths were observed even in the group subjected to 75% monthly leaves exploration. In order not to produce damage to palm trees development it is suggested that leaf extraction rate should not exceed 25% monthly as well as pausing of extractive activity preferentially during fruit maturation.

RELATIONSHIP BETWEEN CLIMATE VARIABLES, TRUNK GROWTH RATE AND WOOD DENSITY OF Eucalyptus grandis W. Mill ex Maiden TREES

ABSTRACT Climatic conditions stimulates the cambial activity of plants, and cause significant changes in trunk diameter growth and wood characteristics. The objective of this study was to evaluate the influence of climate variables in the diameter growth rate of the stem and the wood density of Eucalyptus grandis trees in different classes of the basal area. A total of 25 Eucalyptus trees at 22 months of age were selected according to the basal area distribution. Dendrometer bands were installed at the height of 1.30 meters (DBH) to monitor the diameter growth every 14 days, for 26 months. After measuring growth, the trees were felled and wood discs were removed at the DBH level to determine the radial density profile through x-ray microdensitometry and then re-scale the average values every 14 days. Climatic variables for the monitoring period were obtained and grouped every 14 days. The effect of the climate variables was determined by maximum and minimum growth periods in assessing trunk growth. These growth periods were related with precipitation, average temperature and relative air humidity. The re-scaled wood density values, calculated using the radial growth of the tree trunks measured accurately with steel dendrometers, enabled the determination of the relationship of small changes in wood density and the effect of the climatic variations and growth rate of eucalyptus tree trunks. A high sensitivity of the wood density to variation in precipitation levels was found.

Pressure compensating microsprinklers using microtube as a flow controller

ABSTRACT Microsprinkler non-pressure compensating nozzles usually show water flow variation along the lateral line. This study aimed at adapting microtubes into non-compensating system of microsprinklers previous installed in the field, as a self-compensated nozzle, to improve the flow uniformity along the lateral line. Microtubes were adapted to three types of commercial microsprinklers. Tests were conducted, both in the laboratory and in field, to evaluate the microsprinkler performance at four different flows (40, 50, 60 and 70 L h-1) under pressure head range from 75 to 245 kPa. Nozzles presented coefficient of flow-rate variation (CVq) lower than 5.5% and distribution uniformity (DU) greater than 95%, which are classified as excellent. The original spatial water distribution of the microsprinkler did not change by using microtube as a nozzle. This device adapted to non-pressure compensating microsprinklers are functional and operate effectively with flows ranging up to 70 L h-1. Small variations at microsprinkler flows along the lateral line can occur, however, at random manner, which is common for pressure-compensating nozzles. Therefore, the microtube technique is able to control pressure variation in microsprinklers.

Application of a Pid+fuzzy controller on the motion control system in machine tools

This work deals with an hybrid PID+fuzzy logic controller applied to control the machine tool biaxial table motions. The non-linear model includes backlash and the axis elasticity. Two PID controllers do the primary table control. A third PID+fuzzy controller has a cross coupled structure whose function is to minimise the trajectory contour errors. Once with the three PID controllers tuned, the system is simulated with and without the third controller. The responses results are plotted and compared to analyse the effectiveness of this hybrid controller over the system. They show that the proposed methodology reduces the contour error in a proportion of 70:1.

A modified contour error controller for a high speed XY table

This article deals with a contour error controller (CEC) applied in a high speed biaxial table. It works simultaneously with the table axes controllers, helping them. In the early stages of the investigation, it was observed that its main problem is imprecision when tracking non-linear contours at high speeds. The objectives of this work are to show that this problem is caused by the lack of exactness of the contour error mathematical model and to propose modifications in it. An additional term is included, resulting in a more accurate value of the contour error, enabling the use of this type of motion controller at higher feedrate. The response results from simulated and experimental tests are compared with those of common PID and non-corrected CEC in order to analyse the effectiveness of this controller over the system. The main conclusions are that the proposed contour error mathematical model is simple, accurate, almost insensible to the feedrate and that a 20:1 reduction of the integral absolute contour error is possible.

Analysis of open CNC architecture for machine tools

The evolution of digital circuit technology, leadind to higher speeds and more reliability allowed the development of machine controllers adapted to new production systems (e.g., Flexible Manufacturing Systems - FMS). Most of the controllers are developed in agreement with the CNC technology of the correspondent machine tool manufacturer. Any alterations or adaptation of their components are not easy to be implemented. The machine designers face up hardware and software restrictions such as lack of interaction among system's elements and impossibility of adding new function. This is due to hardware incompatibility and to software not allowing alterations in the source program. The introduction of open architecture philosophy propitiated the evolution of a new generation of numeric controllers. This brought the conventional CNC technology to the standard IBM - PC microcomputer. As a consequence, the characteristics of the CNC (positioning) and the microcomputer (easy of programming, system configuration, network communication etc) are combined. Some researchers have addressed a flexible structure of software and hardware allowing changes in the hardware basic configuration and all control software levels. In this work, the development of open architecture controllers in the OSACA, OMAC, HOAM-CNC and OSEC architectures is described.

Controle químico de plantas daninhas na semeadura direta de tomate (Lycopersicon esculentum Mill.)

Em dois ensaios, um conduzido em Viçosa, MG, e outro em Domingos Martins, ES, estudou-se o comportamento dos herbicidas metribuzin, chloramben, napropamide, diphenamid, pebulate e trifluralin, nas doses de 0,36; 2,40; 2,50; 2,00; 3,60 e 0,67 kg/ha, respectivamente, e a combinação de 0,35 kg/ha de metribuzin com cada um dos demais, nas mesmas doses, no controle de plantas daninhas e na tolerância da cultura do tomate semeado diretamente no local definitivo. Num terceiro ensaio, conduzido em Viçosa, fez-se o mesmo estudo, combinando pebulate, nas doses 4,32 e 5,76 kg/ha, com chloramben, napropamide, diphenamid e metribuzin, nas doses de 3,40; 3,00; 5,00 e 0,70 kg/ha, respectivamente, e também os mesmos compostos, isoladamente, nas mesmas doses. Todos os herbicidas avaliados exerceram controle sobre as plantas daninhas; entretanto, a eficiência de cada um foi muito influenciada pela espécie presente. Apenas pebulate apresentou eficiente controle da tiririca (Cyperus rotundus L.). Chloramben, napropamide, diphenamid e trifluralin controlaram eficientemente capim-marmelada (Brachiaria plantaginea (Link.) Hitch.) e capim-colchão (Digitaria Sanguinalis (L.) Scop.). Metribuzin apresentou excelente controle de picão-preto (Bidens pilosa L.) e botão-de-ouro (Galin-soga parviflora Cav.). As misturas demetribuzin ou de pebulate com os demais herbicidas aumentaram a eficiência de controle e o número de espécies controladas. Nenhum dos herbicidas, nas doses estudadas, causou danos à cultura e os maiores pesos de matéria verde da parte aérea das plantas de tomate foram obtidos nos tratamentos que proporcionaram maior controle de plantas daninhas.

Efeitos alelopaticos de alguns extratos vegetais na germinação do tomateiro (Lycopersicon esculentum Mill. cv. Santa Cruz)

O presente trabalho teve por finalidade avaliar os possíveis efeitos alelopáticos de três plantas daninhas (Cyperus rotundus, Sorghum halepense e Cynodon dactylon), uma leguminosa (Canavalia ensiformis) e colza (Brassica napus), na germinação das sementes do tomateiro (Lycopersicon esculentum cv. Santa Cruz) utilizado como indicador. Tubérculos de tiririca, rizomas de capim massambará, o sistema radicular de grama seda, além de folhas e raízes de feijão-de-porco e colza, foram homogeneizados em solução aquosa, submetidos a filtração e centrifugação. A aplicação do sobrenadante no substrato de germinação das sementes de tomateiro mostrou afetar o processo germinativo e o desenvolvimento da radícula e do hipocótilo. C. rotundus, S. halepense e raízes de C. ensiformis possuem substâncias altamente inibitórias à germinação do tomateiro 'Santa Cruz'', sendo que a planta indicadora também mostrou-se sensível às substâncias presentes nas folhas de B. napus e em C. dactylon.

Estimativa da área foliar de plantas daninhas: Solanum americanum Mill

A maria pretinha (Solanum americanum Mill) é uma planta daninha infestante de diversas culturas e além da competição pode causar outros problemas. Nos estudos envolvendo a biologia e o controle de plantas daninhas, a área foliar é uma das mais importantes características a serem avaliadas, mas tem sido pouco estudada porque sua determinação exige equipamentos sofisticados ou utiliza técnicas destrutivas. Visando obter equações que permitissem a estimativa da área foliar desta planta daninha utilizando características lineares do limbo foliar, facilmente mensuráveis em plantas no campo, foram estudadas correlações entre a área foliar real e as seguintes características das folhas: comprimento ao longo da nervura principal (C), largura máxima do limbo (L) e o produto (C x L). Para tanto, foram mensuradas 200 folhas coletadas de plantas sujeitas às mais diversas condições ecológicas em que a espécie sobrevive, considerando-se todas as folhas das plantas desde que não apresentassem deformações oriundas de fatores, tais como, pragas, moléstias e granizo. Todas as equações, lineares simples, geométricas e exponenciais, permitiram boa estimativa da área foliar (Af) da maria pretinha. Do ponto de vista prático, sugere-se optar pela equação linear simples envolvendo o produto (C x L), a qual apresentou o menor QM Resíduo. Assim, a estimativa da área foliar de S. americanum pode ser efetuada pela equação AF = 0,5632 x (C x L), com coeficiente de determinação (R2) de valor igual a 0,9516.

Characterization of a methionine-rich protein from the seeds of Cereus jamacaru Mill. (Cactaceae)

We describe here the isolation and characterization of a major albumin from the seeds of Cereus jamacaru (Cactaceae), to which we gave the trivial name of cactin. This protein has a molecular mass of 11.3 kDa and is formed by a light chain (3.67 kDa) and a heavy chain (7.63 kDa). This protein was isolated using a combination of gel filtration chromatography and reverse-phase HPLC. The amino acid composition of cactin was determined and found to resemble that of the 2S seed reserve protein from the Brazil nut, a protein remarkable for its high methionine content. The usefulness of cactin as a molecular marker in the taxonomy of the Cactaceae is discussed.

Participation of the GABAergic system in the anesthetic effect of Lippia alba (Mill.) N.E. Brown essential oil

The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA A receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA A receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.

Ciclo de maturação e produção de etileno de tomates (Lycopersicon esculentum, Mill.) transgênicos

Objetivou-se estudar o comportamento fisiológico de frutos de tomateiro (Lycopersicon esculentum, Mill.), da cv. Kadá, transformados geneticamente, via Agrobacterium tumefaciens, com o clone de DNA pMEL1, em orientação antisenso, e de frutos desta mesma cultivar, não transformados. O estudo fisiológico foi realizado avaliando-se a duração do ciclo de maturação dos frutos, amadurecidos na planta e após a colheita no estádio verde-maduro, e sua produção de etileno. Os frutos transformados amadurecidos na planta tiveram um ciclo total médio de 27 dias, enquanto os amadurecidos após a colheita, tiveram este intervalo prolongado a 50 dias. Ao contrário, os tomates não transformados apresentaram um ciclo de maturação mais acelerado quando colhidos no estádio verde-maduro, em relação aos frutos amadurecidos nas plantas. Os valores foram, em média, de 20 e 30 dias, respectivamente. Estes resultados estão correlacionados com as variações na produção de etileno observada nos dois genótipos. Frutos não transformados produziram, em média, 10,46 nL de etileno.g-1.h-1, enquanto os transgênicos tiveram sua produção de etileno diminuída para 0,13 nL.g-1.h-1. Pode-se concluir, então, que a redução da produção de etileno, verificada nos tomates transformados, é necessária, mas não é suficiente para prolongar o ciclo de maturação e aumentar a durabilidade dos frutos. Para que isto ocorra, é necessário que se proceda à colheita dos tomates no estádio verde-maduro.