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1.
Sci. agric ; 70(5)2013.
Article in English | LILACS-Express | VETINDEX | ID: biblio-1497359

ABSTRACT

Due to new possibilities for using sugarcane (Saccharum spp.) trash for electricity generation, and the production of 2nd generation ethanol and others chemicals, the interest for its recovery has increased. However, the question of how much trash can be removed from sugarcane field still needs to be clarified. This study evaluated the amount of dry matter, nutrients content, structural compounds and efficiency of the enzymatic hydrolysis of the hydrothermal pretreated materials for tops and dry leaves in samples from sugarcane varieties. Tops and dry leaves present differences in nutrients content and moisture. Therefore, the amount of trash to be collected should not be simply based on percentages, but also should take into account the different fractions of the crop residues. For instance, around 80 % of N, P and K were derived from tops. Therein, the environmental indicators of the entire chain of sugarcane could be benefited because more nutrients would be recycled and less mineral fertilizers might be used for sugarcane production if tops are left on the field. Further, the tops have seven times more moisture than dry leaves and higher amounts of extractives (organic compounds of low molecular weight). Moreover, as the result of yield obtained in the pretreatment steps for dry leaves were superior to the tops and the glucose yields obtained in the enzymatic hydrolysis step were similar, it can be predicted that for second generation ethanol production, it is more viable to recover parts of the dry leaves fraction, leaving the tops on the field.

2.
Sci. agric ; 70(5)2013.
Article in English | LILACS-Express | VETINDEX | ID: biblio-1497365

ABSTRACT

Mechanized sugarcane (Saccharum spp.) harvest without burning has been increasingly adopted in Brazil, increasing trash availability on the field. This study aims at showing the importance of using an integrated framework tool to assess technical and economic impacts of integral harvesting and baling trash recovery strategies and different recovery rates as well as its implications in the sugarcane production, transport and processing stages. Trash recovery using baling system presents higher costs per unit of mass of recovered trash in comparison to system in which trash is harvested and transported with sugarcane stalks (integral harvesting system). However, the integrated agricultural and industrial assessment showed that recovering trash using baling system presents better economic results (higher internal rate of return and lower ethanol production cost) than the integral harvesting system for trash recovery rates higher than 30 %. Varying trash recovery fraction, stalks productivity and mean transport distance for both integral harvesting and baling systems, sensitivity analyses showed that higher trash recovery fractions associated with higher stalks yields and long transport distances favors baling system, mainly due to the reduction of bulk load density for integral harvesting system under those conditions.

3.
Sci. agric. ; 70(5)2013.
Article in English | VETINDEX | ID: vti-440737

ABSTRACT

Mechanized sugarcane (Saccharum spp.) harvest without burning has been increasingly adopted in Brazil, increasing trash availability on the field. This study aims at showing the importance of using an integrated framework tool to assess technical and economic impacts of integral harvesting and baling trash recovery strategies and different recovery rates as well as its implications in the sugarcane production, transport and processing stages. Trash recovery using baling system presents higher costs per unit of mass of recovered trash in comparison to system in which trash is harvested and transported with sugarcane stalks (integral harvesting system). However, the integrated agricultural and industrial assessment showed that recovering trash using baling system presents better economic results (higher internal rate of return and lower ethanol production cost) than the integral harvesting system for trash recovery rates higher than 30 %. Varying trash recovery fraction, stalks productivity and mean transport distance for both integral harvesting and baling systems, sensitivity analyses showed that higher trash recovery fractions associated with higher stalks yields and long transport distances favors baling system, mainly due to the reduction of bulk load density for integral harvesting system under those conditions.

4.
Sci. agric. ; 70(5)2013.
Article in English | VETINDEX | ID: vti-440731

ABSTRACT

Due to new possibilities for using sugarcane (Saccharum spp.) trash for electricity generation, and the production of 2nd generation ethanol and others chemicals, the interest for its recovery has increased. However, the question of how much trash can be removed from sugarcane field still needs to be clarified. This study evaluated the amount of dry matter, nutrients content, structural compounds and efficiency of the enzymatic hydrolysis of the hydrothermal pretreated materials for tops and dry leaves in samples from sugarcane varieties. Tops and dry leaves present differences in nutrients content and moisture. Therefore, the amount of trash to be collected should not be simply based on percentages, but also should take into account the different fractions of the crop residues. For instance, around 80 % of N, P and K were derived from tops. Therein, the environmental indicators of the entire chain of sugarcane could be benefited because more nutrients would be recycled and less mineral fertilizers might be used for sugarcane production if tops are left on the field. Further, the tops have seven times more moisture than dry leaves and higher amounts of extractives (organic compounds of low molecular weight). Moreover, as the result of yield obtained in the pretreatment steps for dry leaves were superior to the tops and the glucose yields obtained in the enzymatic hydrolysis step were similar, it can be predicted that for second generation ethanol production, it is more viable to recover parts of the dry leaves fraction, leaving the tops on the field.

5.
Article in Portuguese | LILACS-Express | VETINDEX | ID: biblio-1477515

ABSTRACT

Sugar cane harvester performs five simple operations involving cutting of the stems in the base and in the top, feeding of the stems into the interior of the harvester, removing the leaves and cutting the stem in billets, which is optional. However, nowadays, there is a lack of processes to make these operations in an efficient way. The base cutter used in the conventional harvesters is made of double discs positioned in the inter row, however it is not adapted for the furrow planting system used in Brazil, and since it does not present capability of independent flotation for each disk, it causes the movement of a great amount of soil. This research project aimed to design, simulate, construct and evaluate in soil bin a four bar linkage suspension for a sugar cane base cutter to be used in a semi-mechanized harvesting system. The simulations allowed determining the suspension spring stiffness and its initial deformation in order to guarantee the flotation of the mechanism on the soil profile. The mechanism designed was built and mounted on a soil bin carriage for evaluation of the tracking performance of the base cutter when moving on a soil sine wave profile with amplitude of 25 and 50mm and 1.5m length. The results show that the mechanism accomplishes its objectives satisfactory with errors between 8 and 9mm for forward speeds of 0.14m s-1 and 0.42m s-1 respectively.


A colheita da cana-de-açúcar envolve cinco operações básicas, que são o corte dos colmos na base, o corte dos colmos no ponteiro, a alimentação dos colmos para o interior da colhedora, a retirada das folhas e a picagem do colmo, que é opcional. No entanto, ainda hoje há uma carência de processos para efetuar estas operações de forma eficiente. O corte de base utilizado nas colhedoras convencionais é composto de discos duplos posicionados na entrelinha, entretanto, não é adaptado para o sistema de plantio no sulco e, como não apresenta recursos de flutuação independente para cada disco, implica a movimentação de grande quantidade de solo. A ausência de mecanismo flutuante provoca aumento dos índices de impurezas na carga, que implicam a redução da qualidade tecnológica da matéria-prima fornecida para moagem e perdas de cana no campo, além de que requer alta potência para cortar e movimentar o volume de solo. A presente pesquisa teve por objetivos projetar, simular, construir e avaliar em caixa de solo uma suspensão pantográfica para o cortador basal de cana-de-açúcar para ser aplicado em sistema semimecanizado de colheita. As simulações permitiram a obtenção da rigidez da mola da suspensão pantográfica e sua deformação na montagem de forma que permitisse a flutuação do mecanismo de corte basal sobre o perfil do solo. Tal condição pôde ser obtida na medida em que a força de interação patim-solo fosse mínima e não nula. A suspensão pantográfica projetada foi construída e montada em caixa de solo para avaliação em perfil de solo senoidal com amplitude entre 25mm e 50mm e distância entre sulcos de 1,5m. Os resultados demonstraram que o mecanismo projetado realiza o seguimento do perfil do solo de forma satisfatória com erro médio de 8mm e 9mm para as velocidades de deslocamento da colhedora de 0,14m s-1 e 0,42m s-1, respectivamente.

6.
Ci. Rural ; 39(3)2009.
Article in Portuguese | VETINDEX | ID: vti-705857

ABSTRACT

Sugar cane harvester performs five simple operations involving cutting of the stems in the base and in the top, feeding of the stems into the interior of the harvester, removing the leaves and cutting the stem in billets, which is optional. However, nowadays, there is a lack of processes to make these operations in an efficient way. The base cutter used in the conventional harvesters is made of double discs positioned in the inter row, however it is not adapted for the furrow planting system used in Brazil, and since it does not present capability of independent flotation for each disk, it causes the movement of a great amount of soil. This research project aimed to design, simulate, construct and evaluate in soil bin a four bar linkage suspension for a sugar cane base cutter to be used in a semi-mechanized harvesting system. The simulations allowed determining the suspension spring stiffness and its initial deformation in order to guarantee the flotation of the mechanism on the soil profile. The mechanism designed was built and mounted on a soil bin carriage for evaluation of the tracking performance of the base cutter when moving on a soil sine wave profile with amplitude of 25 and 50mm and 1.5m length. The results show that the mechanism accomplishes its objectives satisfactory with errors between 8 and 9mm for forward speeds of 0.14m s-1 and 0.42m s-1 respectively.


A colheita da cana-de-açúcar envolve cinco operações básicas, que são o corte dos colmos na base, o corte dos colmos no ponteiro, a alimentação dos colmos para o interior da colhedora, a retirada das folhas e a picagem do colmo, que é opcional. No entanto, ainda hoje há uma carência de processos para efetuar estas operações de forma eficiente. O corte de base utilizado nas colhedoras convencionais é composto de discos duplos posicionados na entrelinha, entretanto, não é adaptado para o sistema de plantio no sulco e, como não apresenta recursos de flutuação independente para cada disco, implica a movimentação de grande quantidade de solo. A ausência de mecanismo flutuante provoca aumento dos índices de impurezas na carga, que implicam a redução da qualidade tecnológica da matéria-prima fornecida para moagem e perdas de cana no campo, além de que requer alta potência para cortar e movimentar o volume de solo. A presente pesquisa teve por objetivos projetar, simular, construir e avaliar em caixa de solo uma suspensão pantográfica para o cortador basal de cana-de-açúcar para ser aplicado em sistema semimecanizado de colheita. As simulações permitiram a obtenção da rigidez da mola da suspensão pantográfica e sua deformação na montagem de forma que permitisse a flutuação do mecanismo de corte basal sobre o perfil do solo. Tal condição pôde ser obtida na medida em que a força de interação patim-solo fosse mínima e não nula. A suspensão pantográfica projetada foi construída e montada em caixa de solo para avaliação em perfil de solo senoidal com amplitude entre 25mm e 50mm e distância entre sulcos de 1,5m. Os resultados demonstraram que o mecanismo projetado realiza o seguimento do perfil do solo de forma satisfatória com erro médio de 8mm e 9mm para as velocidades de deslocamento da colhedora de 0,14m s-1 e 0,42m s-1, respectivamente.

7.
Ci. Rural ; 39(3)2009.
Article in Portuguese | VETINDEX | ID: vti-705776

ABSTRACT

Sugar cane harvester performs five simple operations involving cutting of the stems in the base and in the top, feeding of the stems into the interior of the harvester, removing the leaves and cutting the stem in billets, which is optional. However, nowadays, there is a lack of processes to make these operations in an efficient way. The base cutter used in the conventional harvesters is made of double discs positioned in the inter row, however it is not adapted for the furrow planting system used in Brazil, and since it does not present capability of independent flotation for each disk, it causes the movement of a great amount of soil. This research project aimed to design, simulate, construct and evaluate in soil bin a four bar linkage suspension for a sugar cane base cutter to be used in a semi-mechanized harvesting system. The simulations allowed determining the suspension spring stiffness and its initial deformation in order to guarantee the flotation of the mechanism on the soil profile. The mechanism designed was built and mounted on a soil bin carriage for evaluation of the tracking performance of the base cutter when moving on a soil sine wave profile with amplitude of 25 and 50mm and 1.5m length. The results show that the mechanism accomplishes its objectives satisfactory with errors between 8 and 9mm for forward speeds of 0.14m s-1 and 0.42m s-1 respectively.


A colheita da cana-de-açúcar envolve cinco operações básicas, que são o corte dos colmos na base, o corte dos colmos no ponteiro, a alimentação dos colmos para o interior da colhedora, a retirada das folhas e a picagem do colmo, que é opcional. No entanto, ainda hoje há uma carência de processos para efetuar estas operações de forma eficiente. O corte de base utilizado nas colhedoras convencionais é composto de discos duplos posicionados na entrelinha, entretanto, não é adaptado para o sistema de plantio no sulco e, como não apresenta recursos de flutuação independente para cada disco, implica a movimentação de grande quantidade de solo. A ausência de mecanismo flutuante provoca aumento dos índices de impurezas na carga, que implicam a redução da qualidade tecnológica da matéria-prima fornecida para moagem e perdas de cana no campo, além de que requer alta potência para cortar e movimentar o volume de solo. A presente pesquisa teve por objetivos projetar, simular, construir e avaliar em caixa de solo uma suspensão pantográfica para o cortador basal de cana-de-açúcar para ser aplicado em sistema semimecanizado de colheita. As simulações permitiram a obtenção da rigidez da mola da suspensão pantográfica e sua deformação na montagem de forma que permitisse a flutuação do mecanismo de corte basal sobre o perfil do solo. Tal condição pôde ser obtida na medida em que a força de interação patim-solo fosse mínima e não nula. A suspensão pantográfica projetada foi construída e montada em caixa de solo para avaliação em perfil de solo senoidal com amplitude entre 25mm e 50mm e distância entre sulcos de 1,5m. Os resultados demonstraram que o mecanismo projetado realiza o seguimento do perfil do solo de forma satisfatória com erro médio de 8mm e 9mm para as velocidades de deslocamento da colhedora de 0,14m s-1 e 0,42m s-1, respectivamente.

8.
Article in Portuguese | LILACS-Express | VETINDEX | ID: biblio-1477116

ABSTRACT

Quality losses of fresh market fruit are often related to mechanical damages that occur from harvest thru final consumer. Those damages normally occur when fruits drop from high heights or collide against not protected surfaces or against other fruits. The main goal of this work was to evaluate in laboratory for impact magnitude and tomato quality different surfaces in three drop heights. For measuring impact magnitude it was used the instrumented sphere and for tomato quality the evaluation was based on internal bruising. Fruit drop tests were done using three protective surfaces that showed different levels of maximum acceleration combined with three different heights. It was concluded that the use of determined protective surfaces rubber plate, under low drop high can decrease internal bruising incidence and impact magnitude on packing lines.


A perda de qualidade do tomate está relacionada muitas vezes a danos mecânicos que ocorrem desde a colheita até o consumidor, quando os frutos são submetidos a quedas em superfícies não-protegidas ou colidem com outros frutos. O objetivo deste trabalho foi avaliar diferentes superfícies e três alturas de queda com relação à magnitude de impacto e à influência na qualidade do tomate de mesa. Para mensurar a magnitude de impacto, utilizou-se a esfera instrumentada. Já a qualidade dos frutos foi avaliada por meio da análise dos danos internos. Para isso, utilizaram-se três superfícies que apresentaram níveis diferentes de impacto combinadas às três alturas de queda. Como resultado, observou-se que as superfícies emborrachadas, por apresentarem uma maior elasticidade, combinadas a menores alturas de queda, demonstram uma maior absorção do impacto e conseqüentemente menor incidência de danos mecânicos.

9.
Ci. Rural ; 37(3)2007.
Article in Portuguese | VETINDEX | ID: vti-705325

ABSTRACT

Quality losses of fresh market fruit are often related to mechanical damages that occur from harvest thru final consumer. Those damages normally occur when fruits drop from high heights or collide against not protected surfaces or against other fruits. The main goal of this work was to evaluate in laboratory for impact magnitude and tomato quality different surfaces in three drop heights. For measuring impact magnitude it was used the instrumented sphere and for tomato quality the evaluation was based on internal bruising. Fruit drop tests were done using three protective surfaces that showed different levels of maximum acceleration combined with three different heights. It was concluded that the use of determined protective surfaces rubber plate, under low drop high can decrease internal bruising incidence and impact magnitude on packing lines.


A perda de qualidade do tomate está relacionada muitas vezes a danos mecânicos que ocorrem desde a colheita até o consumidor, quando os frutos são submetidos a quedas em superfícies não-protegidas ou colidem com outros frutos. O objetivo deste trabalho foi avaliar diferentes superfícies e três alturas de queda com relação à magnitude de impacto e à influência na qualidade do tomate de mesa. Para mensurar a magnitude de impacto, utilizou-se a esfera instrumentada. Já a qualidade dos frutos foi avaliada por meio da análise dos danos internos. Para isso, utilizaram-se três superfícies que apresentaram níveis diferentes de impacto combinadas às três alturas de queda. Como resultado, observou-se que as superfícies emborrachadas, por apresentarem uma maior elasticidade, combinadas a menores alturas de queda, demonstram uma maior absorção do impacto e conseqüentemente menor incidência de danos mecânicos.

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