Paper presented at the International Symposium on Bananas and Plantains: Towards Sustainable Global Production and Improved Use, held October 10-14, 2011, Salvador (Bahia), Brazil. Includes references Bananas are often grown in mixed cropping systems. In Latin America, small growers cultivate bananas with minimal labor and purchased inputs in shaded coffee as a source of monthly income to supplement annual coffee sales. We deployed the framework of agroecological intensification in collaboration with six groups of small coffee growers in Costa Rica, Honduras, Nicaragua and Peru to assess the potential to improve the productivity of banana in mixed systems. After a formal diagnostic study of 30 smallholder coffee farms in each site carried out by scientists, farmer experimentation groups in the same sites did their own diagnostic sampling and identified priority areas for experimentation. Scientists and farmers developed prototypes for system improvement, and alternative management approaches of system components, labor and inputs. Across pilot zones, ‘Gros Michel’ was the most common cultivar, with banana mat density from 300 to 600 mats/ha with 950 to 1200 pseudostems/ha. Tree density varied from 150 to 550 trees/ha with available light ranging from 50 to 70%, and from 35 to 45% for banana and coffee. Farmer priorities across zones were similar: tree, banana and coffee resource partitioning; improved nutrition; coffee pruning; Fusarium wilt management; and marketing for better banana prices. Prototypes for testing addressed: light partitioning among trees, bananas and coffee; an input-output analysis of nutrients to increase the contribution of nitrogen from shade trees and reorient purchased nutrients; a shifting framework of Fusarium wilt management to address quarantine and cultivar substitution; and a marginal return analysis for step-wise intensification of the system, including banana.
Sterk, B., Ittersum, M.K. van, Leeuwis, C., and Wijnands, F.G.
European journal of agronomy, 2007 May, v. 26, issue 4, p. 401-409.
commercial farms, expert systems, prototypes, sustainable agriculture, demonstration farms, on-farm research, simulation models, farming systems, and new methods
Includes references Farm system modelling and prototyping are two research methods proposed to enhance the process of developing sustainable farm systems. Farm system models provide means to formalize, expand and refine expert knowledge and to integrate this with scientific agro-ecological knowledge at the farm level. The prototyping methodology was developed for the design of more sustainable farm systems, either on experimental or commercial farms. The main features of prototyping are: (1) quantification of goals; (2) emphasis on multiple societal goals; (3) designing as an organizing principle; (4) iteration of system analysis, design and on-farm testing. Hypothetically, farm system modelling could enrich the prototyping methodology and vice versa. Taking a goal-oriented stance, a modelling exercise could reveal design options otherwise overlooked and extrapolation of prototyping results to other conditions and scenarios. The on-farm prototyping work could serve as a source of inspiration and information for farm system modelers. However, little cross-pollination between the modelling and prototyping efforts has occurred, even though the methodologies have been applied in parallel and in one country. Existing reports on prototyping projects merely present their methodological set-up and results, but lack description of the implementation of the methodology. We deemed insight into the implementation of prototyping essential to understand the discrepancy between theory and practice and to investigate the potential for cross-pollination between modelling and prototyping in the future. Three promising leads were identified to assess this potential, i.e. (1) exploring goals of farm systems; (2) exploring options for a change and improvement of farm systems; (3) communication and extrapolation of project output. Analysis of more than two decades of Dutch prototyping research both on experimental and commercial farms indicated that prototyping on commercial farms is a highly localized process. Moreover, although the methodology manual suggests differently, goal formulation was not a distinctive phase of prototyping on commercial farms, so cross-pollination with farm system modelling could not occur (lead 1). As the timely operationalization and the localization of a farm system model demand considerable effort, contributions of farm model explorations to the localized change process on commercial farms (lead 2) seem impractical and unlikely. For communication and extrapolation of prototyping output (lead 3), issue-specific (i.e. focus on a component of the system) models are increasingly used. For this purpose, we hypothesize that there may also be a role for farm system models.
Includes references The main objective of this study was to model and simulate a reduced three-dimensional (3D) model for designing the driving system of an automatic vacuum packer. The 3D reduced model consisted of a pressing board sub-model, a taping sub-model, and a vibrating board sub-model. The reduced 3D model was parameterised using the variable of pouch thickness. The sub-models were driven by three virtual motors. To fulfil the required processing capacity of 6 pouches min-1 (pouch size of 45 cm by 35 cm; 5 kg-1 pouch) of the vacuum packer, three rotational motions for the motors were properly designed. When sub-models were driven according to the developed motions, the rated powers of the motors were estimated to be 100, 25, and 90 W, respectively. A real prototype of the vacuum packer was manufactured and controlled according to the developed motions to validate the simulation results. The motors determined by simulating the reduced 3D model drove the three units of the real prototype successfully. The developed motions of the motors satisfied the required operating sequences of the vacuum packer with a processing capacity of 6.7 pouches min-1. Vacuum-packaging tests showed that the success rate of the vacuum packer was 92.6%.
Romero Gómez, J., Ferreiro Garcia, R., Carbia Carril, J., and Romero Gómez, M.
Renewable and sustainable energy reviews, 2013 May, v. 21, p. 1-12.
refrigerators, prototypes, refrigeration, cooling, and temperature
Various AMR refrigerators prototypes have been developed with a view to implementing magnetic refrigeration (MR) at room temperature in a short time. This article describes the working mode of the two basic categories into which these can be divided (reciprocating and rotary) and compares them to show the advantages and disadvantages offered. A review of the latest and most significant alternative linear prototypes is carried out, providing design concepts and performance characteristics. Such characteristics include the operating frequency, magnet field type and field strength, regenerator materials and geometry, and maximum temperature span and cooling capacity. Also included is a study carried out by the authors focused on the prototyping of an MR system aimed at avoiding the shortcomings of other prototypes manufactured to date.
Sørensen, C.G., Jørgensen, R.N., Maagaard, J., Bertelsen, K.K., Dalgaard, L., and Nørremark, M.
Biosystems engineering, 2010 Jan., v. 105, issue 1, p. 119-129.
HortiBot, robots, user interface, prototypes, equipment performance, plant nurseries, design, and agricultural machinery and equipment
Includes references Current service robots have relatively primitive behaviours and limited interaction with the environment. Technological foresights have indicated that the next generation of service robots will demonstrate a high degree of autonomy and reliability, have minimal impact on the environment, and will interact in a flexible way with the user. It is necessary therefore, to determine the functional requirements for a future energy-efficient robotic bioproduction system from the perspective of various stakeholders, together with the development of a high-level framework for designing and prototyping the common functionalities of mobile robots. This study presents technical guidelines for the design of a plant nursing robot. The methodology uses Quality Function Deployment (QFD) functionalities involving the identification of relationships between identified user requirements and the derived design parameters. Extracted important user requirements included: 1) adjustable to row distance and parcel size, 2) profitable, 3) minimize damage to crops, and 4) reliable. Lower ratings were attributed to requirements such as: 1) affection value, prestige, 2) look attractive, 3) out of season operations, and 4) use of renewable energy. Subsequent important derived design parameters included: 1) PreparedForModularTools, 2) ControlableByExternalModules, 3) SemiAutonomous, and 4) Local- and GlobalPositioningSystem. The least important design parameters included: 1) OpenStandardSoftware, 2) Well-builtAppearance, 3) WheelsWithInfiniteSteeringRotation, and 4) InternalSafetySystem. The study demonstrates the feasibility of applying a systematic design technique and procedures for translating the ‘consumer's voice’ into the design and technical specifications of a robotic tool carrier to be used in bioproduction.