Development of a sensitive passive sampler using indigotrisulfonate for the determination of tropospheric ozone

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Assessment of aquatic plants in the reservoirs of AES-Tiete and development of an integrated control model for the most important species

The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tiete as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promissao, and Nova-Avanhandava, located in the Tiete River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Guacu reservoir, which belongs to the Mogi-Guacu River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move floating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants.

Effects of research and extension on agricultural growth and equity in Brazil.

Studies the effects of investment in research and extension on total agricultural production and on production of individual crops. Some distributional effects are briefly discussed. Due to the lack of data, the first part of the analysis is restricted to the State of Sao Paulo, and the second part covers the entire country.-from Author

Effect of different plot coverings on emergence and early development of seven palm species (arecaceae)

The Arecaceae family comprises plants with economical importance in many Brazilian regions, for agricultural exploration or for landscaping. In great portion, species of this family present low germination velocity and percentage. This work meant to evaluate the germination and early development of seven palm species (Archontophoenix alexandrae H. Wendl. et Drude, Copernicia prunifera (Miller) H.E. Moore, Latania commersonii Gmel., Livistona chinensis R. Br., Syagrus campos-portoana Bondar, Syagrus coronata (Mart.) Beccari, Syagrus picrophylla Barb. Rod.), submitted to three kinds of seed bed plot coverings. Three 10 x 2 m seedbeds were built and filled with a mixture of sand, soil and chicken manure (1:3:0.5 proportion), where two lines were sown with each specie. On top of each seedbed, plastic covering and fifty percent screen were set allowing one third of the seedbed to full sunlight exposure. Seedbeds were irrigated by dripping system. All species had the same germination rate, regardless of the covering, by the end of the experiment (146 days after sowing), eventhough, A. alexandrae under plastic covering conditions, L. commersonii at full sunlight exposure and Syagrus campos-portoana under fifty percent shade, had reached that percentage around 51 days after sowing. The remaining species reached the greatest germination percentage earlier with some of the coverings, rather than at full sunlight exposure. For the studied conditions, covering type had no effect in leaf length and width. For leaf number, there was interaction between species x covering type for Livistona chinensis and Copernicia prunifera.

The outlook for agriculture and rural development in the Americas: a perspective on Latin America and the Caribbean, 2009

Includes bibliography

The outlook for agriculture and rural development in the Americas: a perspective on Latin America and the Caribbean, 2010

Includes Bibliography

Inventory and evaluation of natural resources for regional agricultural planning

Includes bibliography

Millennium development goals: progress towards the right to health in Latin america and the Caribbean

Includes bibliography

Climate Change and Development in Latin America and the Caribbean. Overview 2009

Includes bibliography

The contribution of biofuels to the sustainability of development in Latin America and the Caribbean

Includes bibliography

The dynamics of specialist development banking: the case of the agriculture development bank of Trinidad and Tobago

Includes bibliography

Trade and sustainable development: spatial distribution of trade policies impacts on agriculture

Incluye Bibliografía

Development of starch biobased and biodegradable plastics for their use in trays for food-packaging

This research work develops new methods to produce biodegradable starch-based trays for the purpose of replacing expanded polystyrene in the food packaging market. The starch based biopolymers present several drawbacks like poor mechanical properties and very high density. In order to overcome these drawbacks two research lines have been set up: blending thermoplastic starch with biobased reinforcements from agricultural wastes like barley straw and grape wastes, and testing the foamability of these materials with a Microwave-foaming method.

Networked control system for the guidance of a four-wheel steering agricultural robotic platform

A current trend in the agricultural area is the development of mobile robots and autonomous vehicles for precision agriculture (PA). One of the major challenges in the design of these robots is the development of the electronic architecture for the control of the devices. In a joint project among research institutions and a private company in Brazil a multifunctional robotic platform for information acquisition in PA is being designed. This platform has as main characteristics four-wheel propulsion and independent steering, adjustable width, span of 1,80m in height, diesel engine, hydraulic system, and a CAN-based networked control system (NCS). This paper presents a NCS solution for the platform guidance by the four-wheel hydraulic steering distributed control. The control strategy, centered on the robot manipulators control theory, is based on the difference between the desired and actual position and considering the angular speed of the wheels. The results demonstrate that the NCS was simple and efficient, providing suitable steering performance for the platform guidance. Even though the simplicity of the NCS solution developed, it also overcame some verified control challenges in the robot guidance system design such as the hydraulic system delay, nonlinearities in the steering actuators, and inertia in the steering system due the friction of different terrains. Copyright © 2012 Eduardo Pacincia Godoy et al.

Public policies and the competitiveness of agricultural exports

Includes bibliography