Resumo O presente trabalho tem como objetivo obter uma ferramenta computacional para estimar os principais parâmetros do processo FSSW para a indústria de construção naval, utilizando uma abordagem em dois estágios, usando os Métodos de Volumes finitos e Elementos Finitos em domínios com simetria de revolução. Soldas experimentais foram realizadas em duas placas de liga de alumínio AA6082 com 3mm de espessura. Da comparação entre os resultados numéricos e experimentais, as temperaturas máximas de 423°C estiveram próximas às reportadas pela literatura. Porém, as medidas experimentais foram afetadas pela posição dos termopares embutidos no suporte de aço, medindo valores máximos inferiores, de 302°C. Os campos de velocidades circunferenciais e suas zonas de altos gradientes foram coincidentes com a zona de mistura revelada no ataque metalográfico. A técnica, não obstante, foi bem sucedida apesar das simplificações adotadas.

Abstract The main goal of the present work is to obtain a computational tool for the shipbuilding industry to estimate the main parameters of the FSSW process, by means of a two phase approach using the Finite Volume Method and the Finite Element Method on a two dimensional domain with symmetry of revolution. Experimental weldments were done on two 3mm thick overlapping plates of AA6082 Aluminum alloy. Upon comparison between numerical and experimental results, the contact conditions were well chosen and the maximum temperatures of 423°C were close to those reported in literature. Nevertheless, the experimental measurements were affected by the position of the thermocouples, into the backing steel plate, resulting in lower maxima of 302°C. Circumferential velocity fields and their high gradients zones were coincident with the mixing zone, revealed in the metallurgical attack. The technique was considered successful despite its simplifications.

ABSTRACT The experimental work was carried out during the wet period of the Integral Weed Control Campaign, in plantations of the cold season (June - December) of 2018, in the Sugarcane Growers Farm “Vitalio Acuña”, belonging to the Sugar Mill Dos Ríos, Santiago de Cuba. The objective was to assess the effectiveness of two planting methods for weed management in sugarcane. The experiment was laid out in split plot design using three replications, each plot contained 14 furrows of 100 m long, on a cambisol soil. In each planting methods the weeds coverage at 30, 60, 90 and 120 days after the application of herbicide were determined and field closure was evaluated. The Environmental Impact Coefficient and the pollutant load to the atmosphere were determined. Field closure in dual furrow system occurred 60 days before the traditional one, thus limiting the presence of weeds. There were significant differences between the two planting systems. Traditional plantation required four more tasks for weed control. The performance of more control tasks increased the environmental impact coefficient and the expulsion of polluting gases into the atmosphere. The most effective planting method for weed control in sugarcane was dual furrow system, which at the same time reduces pollution to the environment.

RESUMEN El trabajo se realizó durante el período húmedo de la campaña de Control Integral de Malezas, en plantaciones del periodo junio - diciembre de 2018 de la Unidad Básica de Producción Cañera “Vitalio Acuña”, perteneciente a la Unidad Empresarial de Base Dos Ríos, Santiago de Cuba, con el objetivo de evaluar la efectividad de dos métodos de plantación en el manejo de arvenses en caña de azúcar plantada en época de frío. El ensayo se ejecutó bajo un diseño en franjas, con tres réplicas, cada franja contó de 14 surcos, sobre un suelo Sialitizado Cálcico. A los diferentes métodos de plantación se le determinó la cobertura de arvenses a los 30, 60, 90 y 120 días posteriores a la aplicación de herbicida y se evaluó el cierre de campo. Se determinó el Coeficiente de Impacto Ambiental y la carga contaminante a la atmósfera. El cierre de campo en el surco de base ancha se produjo 60 días antes que el tradicional, limitando así la presencia de las arvenses, donde fue menor el porcentaje de cobertura de las mismas con diferencias significativas respecto a la siembra tradicional, la cual demandó cuatro labores más de control. La realización de mayores cantidades de labores de control aumentó el coeficiente de impacto ambiental y la expulsión de gases contaminantes a la atmósfera. El método de plantación más efectivo para el control de arvenses es el de surcos de base ancha que a la vez reduce la contaminación al medioambiente.