En esta tesis se aborda el planeamiento óptimo en la industria de la fruta de pepita, con especial énfasis en el complejo productivo-industrial de peras y manzanas localizado en la región del alto valle de Río Negro y Neuquén. La toma de decisiones en esta actividad presenta desafíos importantes relacionados con la incertidumbre existente en los segmentos productivo y de comercialización, la naturaleza estacional del negocio y la condición perecedera de sus productos. Especfícamente se estudiaron los tres niveles de toma de decisión principales de cualquier cadena de suministro: estratégico, táctico y operativo.A nivel estratégico, relacionado con la introducción de nuevos ítems a la carterade productos de la empresa, se modeló el problema de reestructuración de la composición varietal. Este problema se considera relevante porque la modificación de la estructura de variedades de peras y manzanas de una chacra involucra grandes inversiones y períodos extensos hasta lograr la entrada en producción de las nuevas plantaciones. En lo que respecta a los niveles de planeamiento táctico y operativo, se modeló la cadena de suministro de la fruta fresca desde los productores hasta los mercados finales, incluyendo las plantas de empaque y las cámaras frigoríficas, con el objeto de planificar los principales ujos e inventarios del sistema.A nivel táctico, sobre la base de pronósticos de cosecha, costos y precios, se procura definir los programas de producción y venta que optimicen el beneficio del negocio.Este modelo permite evaluar el desempeño de diferentes infraestructuras para satisfacer la demanda prevista y estimar los requerimientos de servicios correspondientes. En modo operativo se incluyó un mayor nivel de detalle con el objeto de evaluar el impacto de corto plazo de decisiones operativas. Para posibilitar su resolución en un tiempo razonable y disponer de una forma práctica de reaccionar frente a eventos inciertos, se propone su empleo en el contexto de una estrategia de horizonte móvil. / This thesis addresses optimal planning of the pip-fruit industry with particular emphasis on the productive-industrial complex located in the \Alto Valle de Río Negro y Neuquén" region. Decision making in this industry presents challenging features related to the inherent uncertainty in the productive and commercialization segments, the seasonal nature of the activity and the perishable condition of its products. Speci fically, three decision making levels of any supply chain system were addressed: strategic, tactical and operational. At the strategic level, the restructuring of the apple and pears varieties composition related to the inclusion of new items in the product portfolio of the company was addressed. This problem is considered relevant since the modification of the varieties structure in farms involves large investments and extensive periods until the new plantation production start. Regarding tactical and operative levels, the fresh fruit industry supply chain was modelled from production farms to final markets, including packaging plants and refrigeration facilities, aimed at planning the main uxes and inventories along the system.At the tactical level, based on harvest estimations and costs and prices forecasts, the production plans that optimize the business profit are investigated. This model allows the assessment of diferent infrastructures performance aimed at satisfying the expected demand and estimating the required logistics. In an operational mode, the described supply chain was modelled with a larger level of detail in order to evaluate the short term impact of operative decisions. Aimed at achieving solutions in reasonable computation times and being able to react in the face uncertain events in a practical fashion, its use within a rolling horizon strategy is proposed.

A banana (Musa spp.) está entre as culturas mais abundantes no mundo, e devido ao seu descarte, desde a colheita até a sua comercialização gera-se grande quantidade de resíduos sólidos. Neste cenário, buscou-se avaliar o potencial uso do resíduo de banana (RB) como substrato e fonte de bactérias fermentativas para produção de H2 e metabólitos solúveis. Obteve-se a partir da fermentação natural do RB biomassa autóctone produtora de H2 sem necessidade do uso de fonte exógena de bactérias e custo adicional de fontes de carbono. Nesse consórcio foram identificadas bactérias semelhantes a Lactobacillus e Clostridium. Ensaios em reatores em batelada foram conduzidos para seleção do meio de cultivo (BAC, Noparati e PCS), das variáveis independentes (pH, temperatura, concentração do substrato, headspace e inóculo), seguido do delineamento composto central rotacional (DCCR) para otimização da produção de hidrogênio. Verificou-se que as condições nutricionais do meio PCS (extrato de levedura, peptona, NaCl e CaCO3) e RB resultaram na produção (P) e rendimento (YH2) máximo de 15,05 mL e 10,03 mL H2.g-1 CT (carboidratos totais), respectivamente. Em relação às variáveis independentes (pH, temperatura, concentração de substrato, volume do headspace e porcentagem de inóculo) obteve-se maiores valores de P e velocidade de produção (Rm) de H2 de 38,08 mL e 3,07 mL.h-1, respectivamente, em pH 7,5, 15 g.L-1, 44ºC, 40% de headspace e 15% inóculo. Em relação às variáveis estatisticamente significativas (pH e temperatura) via realização do DCCR observou-se que o aumento do pH (de 5,09 para 7,5) favoreceu, tanto P, quanto Rm, todavia, maior temperatura (de 27,1 para 46,9ºC) associada ao menor pH (<6,5) foram condições desfavoráveis para esses parâmetros. Por outro lado, obteve-se redução do tempo de início de produção de hidrogênio (&#955;H2) para maior temperatura (44-46,9ºC) associada ao menor pH (5,5) As condições operacionais ótimas estimadas via modelo foram em pH 7,0 e 37ºC, obtendo-se 70,09 mL H2, 12,43 mL H2.h-1 e 93 mL.g-1 CT, para P, Rm e YH2, respectivamente. Bacilllus sp. isolada do RB cresceu em variedade de substratos (glicose, xilose, manose, galactose, frutose, maltose, celobiose, sacarose, amido e RB), e 71 mL H2 foi obtido em 5 g.L-1 de RB, pH 7 a 37ºC. Em todos os ensaios em reatores em batelada, independentemente das condições operacionais, verificou-se que as principais vias metabólicas foram do ácido acético butírico e ácido lático, principalmente com glicose e frutose como fonte de carbono. A acidificação dos reatores resultou na diminuição do pH inicial para valores <4,0 favorecendo a rota solventogênica. Na biomassa fermentativa autóctone e aquela dos reatores em batelada foi possível inferir sobre elevado potencial metabólico, devido a identificação de genes relacionados com enzimas do metabolismo de carboidratos. / Banana (Musa spp.) is among the most abundant crops in the world and, due to its discard, great quantity of solid waste is generated from the harvest until its commercialization. In this scenario, the potential use of banana residue (RB) as substrate and source of fermentative bacteria for the production of H2 and soluble metabolites was evaluated. It was obtained from RB natural fermentation native autochthonous H2-producing biomass without the need to use exogenous source of bacteria and additional costs from carbon sources. In this consortium, bacteria similar to Lactobacillus and Clostridium were identified. Batch reactor experiments were conducted to select culture medium (BAC, Noparati and PCS) and independent variables (pH, temperature, substrate concentration, headspace and inoculum), followed by central composite rotatable design (CCRD) experiments for optimization of hydrogen production. It was verified that the nutritional conditions provided by PCS medium (yeast extract, peptone, NaCl and CaCO3) and RB resulted in the maximum production (P) and yield (YH2) of 15.05 mL and 10.03 mL H2 g-1 CT (total carbohydrates), respectively. Regarding the independent variables (pH, temperature, substrate concentration, headspace volume and percentage of inoculum), higher P and H2 production rate (Rm) were obtained (38.08 mL and 3.07 mL h-1, respectively) at pH 7.5, 15 g L-1 of substrate, 44 °C, 40% headspace and 15% inoculum. In relation to the statistically significant variables (pH and temperature), it was observed through CCRD that the increase in pH (from 5.09 to 7.5) favored both P and Rm, however, a higher temperature (from 27.1 to 46.9ºC) associated with lower pH (<6.5) were unfavorable conditions for these parameters. On the other hand, a reduction in the hydrogen production start time (H2) was obtained with higher temperature (44-46.9ºC) associated to lower pH (5.5). The optimum operational conditions, estimated by modeling, were pH 7.0 and 37 °C, yielding 70.09 mL H2, 12.43 mL H2 h-1 and 93 mL gCT-1 for P, Rm and YH2, respectively. Bacillus sp. isolated from RB grown on a variety of substrates (glucose, xylose, mannose, galactose, fructose, maltose, cellobiose, sucrose, starch and RB), and 71 mL H2 was obtained with 5 g L-1 RB, pH 7 at 37 °C. In all batch reactor experiments, regardless of operating conditions, the main metabolic pathways were acetic acid, butyric acid and lactic acid, mainly with glucose and fructose as carbon sources. Acidification of the reactors resulted in a decrease of the initial pH to values <4.0, favoring the solventogenic pathway. It was possible to infer about the high metabolic potential in the autochthonous fermentative biomass and in the biomass from the batch reactors due to the identification of genes related to enzymes of the carbohydrate metabolism.

El objetivo del presente trabajo consiste en realizar un análisis diacrónico y procesual del accionar de la Federación de Productores de Fruta de Río Negro y Neuquén, en el período 1956-1976. El estudio del accionar de las asociaciones agrarias forma parte del proceso de renovación de los estudios agrarios emprendidos a partir de la década de 1980 desde una óptica multidisciplinar. Este trabajo tiene entonces como propósito avanzar hacia la comprensión de los procesos de movilización sociales contemporáneos, protagonizados por sujetos colectivos asociados a la fruticultura, en este caso, los “chacareros” del Alto Valle del río Negro que hacia mediados del siglo XX conformaron la Federación de Productores de Fruta de Río Negro y Neuquén. El recorte temporal efectuado se llevó a cabo teniendo en cuenta el inicio del proceso de provincialización de los territorios nacionales, proceso que coincide con el cambio de modelo económico, con la implementación de las políticas desarrollistas a nivel nacional y con la formación de la asociación que agrupa a las cámaras de productores de fruta Río Negro y Neuquén (Federación de Productores de Fruta de Río Negro y Neuquén), en junio de 1956. Se seleccionó el año 1976 para finalizar este estudio ya que la dictadura iniciada a partir de allí implica un viraje en las políticas económicas hacia el modelo neoliberal. Durante estos veinte años tres organizaciones representaron los intereses de los productores de fruta en el Alto Valle del río Negro y se convirtieron en los principales interlocutores con el Estado provincial y nacional en un contexto signado por una impredecible alternancia entre gobiernos constitucionales y gobiernos de facto y por transformaciones en el agro regional que preanunciaban el auge del ciclo agroindustrial. El accionar de estas asociaciones - gremial, en el caso de la Federación de Productores de Fruta de Río Negro y Neuquén y del Movimiento Regional de Productores de Río Negro y Neuquén y no gremial, en el caso de CORPOFRUT- contribuyó a plasmar una configuración espacial que superó los límites político-administrativos provinciales, construidos sin tener en cuenta la compleja dinámica regional propia de Patagonia norte previa a proceso de provincialización. La formación de estas tres entidades durante una compleja etapa de transición, constituyó parte de las estrategias de sostenimiento de demandas e intereses de los productores de fruta del Alto Valle del río Negro que, lejos de llegar a conformar un bloque homogéneo, una clase social, en el mismo proceso de lucha y de reivindicación de sus intereses comenzaron a presentar principios de diferenciación que conspiraron contra un accionar unificado y sostenido en el tiempo. En el caso de la región a la que se refiere este trabajo, el Alto Valle del río Negro, los tres procesos de producción del espacio que se articularon en el marco de la lógica capitalista: la producción -mercantil-, la dominación -estatal- y la apropiación -social- del espacio, contribuyeron a configurar la región objeto de estudio en este trabajo, al tiempo que permiten comprender por qué las formas de acción colectiva agremiada surgieron a partir del Alto Valle y específicamente en Cinco Saltos, Cipolletti, Allen y Villa Regina, para extenderse luego al resto de la región. Desde el punto de vista metodológico se recurrió a préstamos conceptuales y de estrategias de investigación propias de otras ciencias sociales pero sin olvidar la esencia del método de la investigación histórica y su objetivo: brindar explicaciones globales de los procesos históricos estudiados contextualizando las problemáticas abordadas teniendo en cuenta sus dinámicas internas de cambio. En el caso de la temática a abordar en la presente investigación, la combinación de fuentes documentales escritas con los testimonios orales de sujetos involucrados intencionalmente seleccionados, apuntó a rescatar dos tipos de registros distintos pero contrastables y a la vez complementarios, a “escuchar” dos o más voces. Por ello, la triangulación teórica y metodológica a la que se recurrió desde el enfoque cualitativo, se basa en la premisa de que no existe un único medio para resolver una determinada problemática y que las estrategias de investigación deben adecuarse al problema estudiado, en este caso, el accionar colectivo de los sujetos colectivos asociados a la fruticultura en el Alto Valle del río Negro durante el período comprendido entre los años 1956 y 1976. / The objective of the present work consists on a diachronic and procesual analysis of the actions of the Fruit Producers Federation of Río Negro and Neuquén, between the years 1956 and 1976. The study of the agricultural assosiation´s work is a part of the renewal process of the agrarian studdies undertaken since the 1980´s from a multidisciplinary perspective. This paper then aims to advance on the understanding of the contemporary processes of social movilization, featuring collective subjects associated with fruit-growing, in this case, the "chacareros" of the Alto Valle del río Negro that towards mid20th century conformed the Fruit Producers Federation of Río Negro and Neuquén. The temporary cut made was carried out considering the start of the provicialization process of the national territories, process that coincides with the change of the economic model, with the implementation of the development policies at a national level and with the formation of the asociation that groups the fruit producers cameras of Río Negro and Neuquén (Fruit Producers Federation of Río Negro and Neuquén), on june of 1956. The year 1976 was selected to finish this study since the dictatorship started there implies a turn on the economic policies towards the neoliberal model. During this twenty years three organizations represented the interests of the fruit producers at the Alto Valle del río Negro and they turned into the main interlocutors with the provincial and national State in a context signed by an impredictable alternance between constitucional governments and facto governments and by changes in the regional agro that preanounced the rise of the agroindustrial cycle. The actions of this asociations - guild, in the case of the Fruit Producers Federation of Río Negro and Neuquén and the Regional Movement of Producers of Río Negro and Neuquén, and nonguild, in the case of CORPOFRUT- helped capture a spatial configuration that exeded the provincial political and administrative boundaries, constructed regardless the complex regional dynamics own by northern Patagonia before the provincialization process. The formation of this three entities during a complex transition, was a part of the strategies for support of demands and interests of the Alto Valle del río Negro fruit producers that, far from reaching form a homogeneous block, a social class, in the process of struggle and vindication of their interests began to present principles of differentiation that conspired against a unified action, sustained over time. In the case of the region this work is about, the Alto Valle del río Negro, the three production processes of space articulated within the framewok of capitalist logic: the production - mercantile-, the dominance -statal- and the appropiation -social- of the space, helped shape the region under study in this work, while allowing to understand why the unionized forms of collective action emerged from the Alto Valle and specifically in Cinco Saltos, Cipolletti, Allen and Villa Regina, then spread to the rest of the region. From a methodological point of view it was resorted to conceptual and research strategies loans from of other social sciences but without forgetting the historical research method and its aim: to offer global an explanation of the studied historical processes contextualizing the boarded issues considering their internal exchange dynamics. In the case of the issues to address in the present investigation, the combination of documentary written sources with oral testimonies of individuals involved intentionally selected, pointed to rescue two kinds of records that are different but contrastable and at the same time complementary, to "listen" to two or more voices. Thus, the theoretical and methodological triangulation which was used from a qualitative approach, is based on the premise that there is not one single way to solve a specific problem and that the research strategies must be adapted to the studied problem, in this case, the collective actions of collective subjets asociated whit fruit-growing in the Alto Valle del río Negro during the period of time between the years 1956 and 1976