RESUMO O entendimento dos fenômenos de sorção de água em sementes de castanheira do Brasil permitirá manejar adequadamente esse produto principalmente no que se refere às condições adequadas para um armazenamento seguro. Assim, objetivou-se determinar as isotermas de sorção (dessorção e adsorção) de água de castanha do Brasil, ajustando-se diferentes modelos matemáticos aos dados experimentais, além da histerese. Para a obtenção das isotermas de sorção foi utilizado o método estático, nas temperaturas de 25, 35, 45 e 55 °C para umidades relativas do ar variando entre 10 a 80%. As condições psicrométricas do ar foram obtidas colocando-se no interior de dessecadores materiais higroscópicos, soluções ácidas e salinas saturadas específicas. Verificou-se que para uma dada isoterma, o teor de água de equilíbrio da castanha do Brasil aumenta com a elevação da atividade de água. Além disso, para uma dada atividade de água, o teor de água de equilíbrio diminui com a elevação da temperatura. Os modelos Copace, Henderson e Oswin são os que melhor descrevem a higroscopicidade das sementes de castanheira do Brasil, tanto na adsorção quanto na dessorção. A histerese foi mais pronunciada nas menores temperaturas e para maiores valores de atividade de água. O teor de água que se deve armazenar a castanha em temperaturas menores que 55 °C sem que haja risco de desenvolvimento fúngico deve ser menor que 8,2% (b.s.).

ABSTRACT Knowledge of the water sorption phenomenon in Brazil nut seeds will allow proper handling of this product, especially with regard to adequate conditions for safe storage. Thus, the present study aimed to determine the sorption isotherms (desorption and adsorption) of Brazil nuts, fitting different mathematical models to the experimental data, as well as to examine the hysteresis effect. To obtain the sorption isotherms, the static method was employed at temperatures of 25, 35, 45 and 55 °C and air relative humidities varying from 10 to 80%. The psychrometric conditions of the air were acquired with the aid of acid solutions and specific saturated saline left inside desiccators with the samples. It was verified that for a given isotherm, the equilibrium moisture content of Brazil nuts increases with water activity increment. In addition, at a constant water activity, equilibrium moisture content decreases with temperature increase. The Copace, Henderson and Oswin are the models that best describe the hygroscopicity of the Brazil nut seed for both the adsorption and desorption processes. Hysteresis was more pronounced at lower temperatures and higher values of water activity. The moisture content value for storage at temperatures less than 55 °C, without the risk of fungal development, must be lower than 8.2% (d.b.).

ABSTRACT Bertholletia excelsa (Brazil nut) is the only representative of the Bertholletia genus, but presents great phenotypic variability. The objective of this study was to characterize the fruits, seeds and crude oil of Brazil nuts from the state of Mato Grosso, Brazil. Fruit and seeds from adult trees were collected at the municipalities of Alta Floresta, Cotriguaçu, Itaúba and Juína. Physical characteristics, yield and composition of the seeds, as well as crude oil characteristics were evaluated. The fruits produced in Itaúba were the smallest and had the lowest number of seeds, while those from Juína presented larger size and mass. The nuts produced in Itaúba had the lowest mean unit mass and ten-seed mass values. The seeds produced in Juína presented higher lipid content and lower ash content. The selenium content of the nuts was higher in Cotriguaçu. There were no significant differences in fruit peel thickness, yield and protein content of the nuts or characteristics of the crude oil.

Objetivou-se, neste trabalho, avaliar e modelar as curvas de equilíbrio higroscópico obtidas pelos processos de adsorção e dessorção para os frutos de café (Coffea canephora) maduros (cerejas) para diferentes condições psicrométricas do ar. Nos processos de sorção foram utilizadas diferentes condições de temperatura (entre 10 e 50 °C) e umidade relativa (entre 10 e 95%) até que o produto atingisse o teor de água de equilíbrio com a condição do ar especificada. Aos dados experimentais de sorção foram ajustados diversos modelos matemáticos frequentemente utilizados para representação da higroscopicidade de produtos agrícolas. Verificou-se que o teor de água de equilíbrio dos frutos de café aumentou com a umidade relativa para dada temperatura e diminuiu com o aumento da temperatura para determinada umidade relativa. A histerese foi mais pronunciada na faixa de umidade relativa do ar entre, 65 e 75%. O modelo Sigma-Copace foi o que melhor descreveu a higroscopicidade dos frutos de café, tanto na adsorção quanto na dessorção.

The objectives of this study were to evaluate and to model the isotherms curves obtained by adsorption and desorption processes for the fruits of ripe (cherries) coffee (Coffea canephora), for different psychrometric conditions of the air. For all sorption processes, different conditions of temperature (between 10 and 50 °C) and relative humidity (between 10 and 95%) were used, until the product reached its equilibrium moisture content with the air condition specified. For experimental data of sorption, different mathematical models often use to represent hygroscopicity of agricultural products were adjusted. It was verified that the equilibrium moisture content of the fruits of coffee increased with relative humidity for a given temperature and decreased with increasing temperature for a given relative humidity. The hysteresis, regardless of temperature, was more pronounced for relative humidity of the air between 65 and 75%. The Sigma-Copace model was the best in describing hygroscopicity of the fruits of coffee both in desorption and adsorption.

O tombamento é uma doença de viveiro de grande importância econômica na cultura do mamoeiro e o tratamento de sementes pode ser uma medida eficaz para seu controle. Objetivou-se, neste trabalho, avaliar a qualidade de sementes de mamão, tratadas com fungicidas, em formulação pó molhável, e armazenadas sob duas condições de acondicionamento (embalagens) e de ambiente. Adicionalmente, avaliou-se a eficiência do tratamento com fungicidas no controle do tombamento causado por Rhizoctonia solani. Sementes de mamoeiro (cv. Golden) foram tratadas com os fungicidas captan, tolylfluanid e mistura captan+tolylfluanid. Sementes sem tratamento constituíram a testemunha. As sementes foram armazenadas por nove meses em duas condições: (i) acondicionadas em papel aluminizado e mantidas a 7±1 ºC; (ii) acondicionadas em papel permeável tipo kraft e mantidas em ambiente não controlado. No início e a cada três meses, avaliaram-se a qualidade das sementes (testes de vigor e de germinação), a emergência, o índice de velocidade de emergência, a altura, a massa da matéria seca e o tombamento de plantas, em pré e pós-emergência (substrato com e sem inóculo micelial de R. solani). Ambas as condições de armazenamento bem como os tratamentos fungicidas preservaram a germinação e o vigor das sementes. No substrato infestado, a emergência de plântulas foi favorecida pelos fungicidas, mas, em pós-emergência, estes, sozinhos, não controlaram o tombamento causado por R. solani. Já, em substrato limpo não se observaram sintomas de tombamento. Conclui-se que os tratamentos fungicidas poderão ser utilizados no pré-tratamento de sementes de mamoeiro, para fins de armazenamento prolongado e comercialização.

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

The use of Autonomous Underwater Vehicles (AUVs) for underwater tasks is a promising robotic field. These robots can carry visual inspection cameras. Besides serving the activities of inspection and mapping, the captured images can also be used to aid navigation and localization of the robots. Visual odometry is the process of determining the position and orientation of a robot by analyzing the associated camera images. It has been used in a wide variety of non-standard locomotion robotic methods. In this context, this paper proposes an approach to visual odometry and mapping of underwater vehicles. Supposing the use of inspection cameras, this proposal is composed of two stages: i) the use of computer vision for visual odometry, extracting landmarks in underwater image sequences and ii) the development of topological maps for localization and navigation. The integration of such systems will allow visual odometry, localization and mapping of the environment. A set of tests with real robots was accomplished, regarding online and performance issues. The results reveals an accuracy and robust approach to several underwater conditions, as illumination and noise, leading to a promissory and original visual odometry and mapping technique.

The present paper describes a system for the construction of visual maps ("mosaics") and motion estimation for a set of AUVs (Autonomous Underwater Vehicles). Robots are equipped with down-looking camera which is used to estimate their motion with respect to the seafloor and built an online mosaic. As the mosaic increases in size, a systematic bias is introduced in its alignment, resulting in an erroneous output. The theoretical concepts associated with the use of an Augmented State Kalman Filter (ASKF) were applied to optimally estimate both visual map and the fleet position.