Sugarcane is an important crop for South Africa. It provides employment and valuable foreign / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007

Sweet sorghum produces more carbohydrates and more biomass per unit land area than com in the Eastern U. S. Piedmont. An equipment system for harvesting and processing whole-stalk sweet sorghum is being developed, with the expectation that sweet sorghum can be commercialized as an ethanol feedstock. A whole-stalk harvester was designed, constructed, and tested during the 1988 harvest season. The harvester captured a row of stalks between two counter rotating gathering belts, cut them at the base with a disk cutter (basecutter), and, at the rear of the machine, rotated the stalks 90° by capturing the stalk butts between to spring-loaded disks, called the stalk flipper. At a field speed of 6.7 km/h, the machine worked best when the flipper tangential velocity was 24 percent higher than the gathering belt Linear velocity, which was approximately (within six percent) equal to ground speed. The harvester was pulled behind a tractor and powered with a universal joint drive line. Two computer software packages, Computer-Graphic Augmented Design and Manufacturing (CADAM) and Integrated Mechanisms Program (IMP), were used to design the hitch and drive line. Calculated angular accelerations in the 3-joint drive line were excessive during a right or left turn; consequently a constant velocity joint was used at the tractor PTO. The hitch was designed with three position settings. With the hitch in the Field 1 position, the harvester was offset sufficiently to capture a row with the gathering belts. In the travel position, the harvester trailed behind the tractor within the 2.4 m legal road width. / Master of Science

This study examined the influence of different management practices under sugarcane production on soil chemical, biological and physical properties on a long-term (59yr) field experiment in KwaZulu-Natal. These management practices included conventional post-harvest burning of crop residues, with the tops either left on the soil surface or with tops removed, and green cane harvesting with the retention of crop residues on the soil surface as a trash blanket. Each of these treatments were either fertilized or did not receive fertilizer. The data collected was used to evaluate the effect of crop residue management on soil quality under sugarcane production. Soil organic matter content increased from 39 g C kg¯¹ soil, under conventional burning to 55 g C kg¯¹ soil in the surface 10 cm under green cane harvesting where crop residues are returned to the soil. It also resulted in greater recycling of nutrients and increases in exchangeable K and Ca and extractable P. Fertilizer application resulted in a build-up of soil nutrients in combination with trash retention. Fertilizer application induced increases in exchangeable P and also some accumulation in soil organic P. Exchangeable and non-exchangeable K concentrations were also higher in fertilized than non-fertilized treatments. However, nitrogen fertilizer application and, to a lesser degree, organic matter mineralization, resulted in soil acidification to a depth of 30 cm. Acidification in the fertilized treatments resulted in a concomitant increase in exchangeable acidity and exchangeable Al, due to the increase in H⁺ ions and solubilized Al species on exchange sites. Base cations moved into soil solution and were leaching to lower soil layers. The decrease in soil pH resulted in the surface charge conferred on the variable charge surfaces on soil colloids becoming less negative and as a result there was a decrease in ECEC. Acidification in fertilized treatment not only increased exchangeable Al but also the buffering reserve of non-exchangeable al; both that complexed with soil organic matter (CuCl₂- extractable) and that present as hydroxy - Al associated with mineral colloids (ammonium acetate - extractable). The increased organic matter content under trash retention resulted in an increase in ECEC. This enabled the soil to retain greater amounts of Ca²⁺, Mg²⁺ and K⁺ which were returned to the soil in the trash. Both residue retention and fertilizer application had a positive effect on the microbial biomass C and N and the microbial quotient increased from 0.39% to 0.86% as organic C increased from 39 g C kg¯¹ soil under burnt treatments to 55 g C kg¯¹ soil under trashed, fertilized treatments. This increase was associated with increased concentrations of labile organic material (K₂S0₄₋extractable) present as well as increased amounts of nutrients being cycled through the plant-soil system. The light fraction organic matter also increased with increasing returns of organic residues. However, the large active microbial biomass under the trashed, fertilized treatment resulted in an increased turnover rate of this fraction and consequently resulted in lower LF dry matter, C and N than in the unfertilized treatment. Aggregate stability increased with increasing amounts of organic material returned due to trash retention. Nevertheless, fertilized treatments induced a lower aggregate stability than unfertilized ones, despite the tendancy for the latter to have higher organic C and microbial biomass values. This was attributed to an increase in the proportion of exchangeable cations present in monovalent form (due to application of fertilizer K and leaching of Ca and Mg) favouring dispersion and a decline in aggregate stability. Green cane harvesting resulted in an increase in microbial activity (basal respiration, FDA hydrolytic activity, arginine ammonification rate and dehydrogenase activity) and in the activity of specific soil enzymes involved in turnover of C, N, P and S to a depth of 30 cm. Increased activities of these enzymes reflect a higher rate of turnover of C, N, P and S. The metabolic quotient decreased with increasing residue return, indicating a more metabolically efficient microbial community. Fertilizer application resulted in a variable effect on enzyme activity. Long-term fertilizer application resulted in an increase in invertase and acid phosphatase, a decrease in L-histidase and arylsulphatase and had little effect on protease and alkaline phosphatase. These variable effects were explained in terms of an interaction between fertilizer - induced increases in Corg and soil nutrient status and fertilizer - induced soil acidification. The size and activity of the soil microbial biomass was studied in the plant row and in the inter-row of a sugarcane field under burning or green cane harvesting. Soils were sampled to 30 cm depth in (i) the centre of the plant row, (ii) 30 cm out from the row centre and (iii) 60 cm out from the row centre (i.e. the middle of the inter-row area). Under burning, the only substantial input of organic matter to the soil was from root turnover in the row area where the root biomass was concentrated. As a consequence, the size (microbial biomass C) and activity (basal respiration of the soil microbial community were concentrated in the row. However, under green cane harvesting there was a large input of organic matter in the inter-row area in the form of the trash blanket itself and through turnover of crop roots that were concentrated in the surface 10 cm of the soil below the blanket. As a result, soil microbial activity was considerably higher in the interrow area under green cane harvesting than under burning. Phospholipids are essential membrane components of microorganisms and a good correlation was found between the total PLFA's extracted from soils and the microbial biomass C, indicating that phospholipids are an accurate measurement of living biomass. Mutivariate statistical analysis (PCA) was used to separate different PLFA profiles under burning versus trash retention and under different land uses (sugarcane, maize, annual and perennial pasture and undisturbed veld). Soil organic matter content contributed the greatest variance in the data along the first axis. That is increasing soil organic matter return not only increased the size of the microbial biomass, but also affected the composition of the microbial community. There was a shift in the different sub-fractions under different management practices. MUFA's are general biomarkers of Gram negative bacteria and were found to be a sensitive indicator of higher substrate availability (i.e they increased under green cane harvesting). Fungal biomarkers indicated an increased fungal biomass associated with surface application of residues. Soil physical conditions were considered to be a contributing factor to the shift in microbial community structure. Increased organic matter content improved soil physical conditions and preferentially stimulated the growth of aerobic microorganisms. In addition to this, the proportion of SATFA (gram positive bacteria) was found to increase in response to burning. This increase was attributed to the survival mechanisms of these microorganisms (i.e. endospore formation). It was found that the conversion from burning to trash management changes the composition of the soil microbial community. The effect of management practices on soil functional diversity was also evaluated using two methods (i.e. Biolog plates and substrate induced respiration (SIR)). Biolog plates are a selective technique that stimulate growth of a small proportion of the soil microbial community whereas the SIR technique measures the activity of the metabolically active microbial community in situ. As a result the SIR method separated treatments more effectively than Biolog plates (i.e. annually tilled treatments, permanent grassland sites and fertilized and unfertilized treatments). The quantity and the quality of organic C supply influenced the catabolic diversity. Conversion from burning to green cane harvesting greatly increased catabolic evenness and richness and therefore presumably also tended to increase the resilience of the soil to stress and disturbance particularly in relation to decomposition functions. It was concluded that conversion from preharvest burning to green cane harvesting results in an increase in soil organic matter content, an improvement in soil structure and soil nutrient status, an increase in the size, activity, taxonomic and functional diversity of the soil microbial community. The practice should therefore be promoted to the South African sugar industry. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.

Made available in DSpace on 2014-06-11T19:23:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-01Bitstream added on 2014-06-13T19:49:39Z : No. of bitstreams: 1 silva_lm_me_botib.pdf: 309558 bytes, checksum: ca7e6d3ba3cb545638804298fc66a9c0 (MD5) / O objetivo deste trabalho é propor um modelo matemático que consiste em determinar quais variedades de cana-de-açúcar adaptável ao solo local serão plantadas nos talhões disponíveis de forma a obter o menor custo possível para o processo de colheita e transporte da cana, e ainda desenvolver e testar um algoritmo genético (AG) para investigar a solução deste problema. Inicialmente é feito um breve estudo do ciclo produtivo da cana-de-açúcar, dos prazos para a eliminação de sua queima e do custo, de sua colheita e transporte até a usina. Em seguida estuda-se o algoritmo Branch-and-Bound, o qual dentre os métodos exatos é bastante utilizado para resolver Problemas de Programação Linear Inteira (PPLI). Para testar e comparar a performance do algoritmo genético com o Branch-and-Bound foram realizadas quatro simulações com diferentes áreas de plantio e número de variedades, simulando situações reais na região geográfica trabalhada. Os resultados foram analisados e discutidos neste texto, mostrando que o algoritmo genético pode ser uma ferramenta alternativa e de grande utilidade para problemas de grande porte / The objetive of this study is to propose a mathematical model that consist of determining which varieties of sugar cane adaptable to local soil should be planted in plots available in order to obtain the lowest cost to the process of harvesting and transportation of cane, and further develop and test a genetic algorithm (GA) to investigate the solution of this problem. Initially it has been done a short study of the production cycle of sugar cane, the deadline for the elimination of his burns and the cost of harvest and transport to the mill. In the next step, we studied the algorithm Branch-and-Bound, which among methods available is often employed to solve Integer Linear Programming Problems (PPLI). To test and compare the performance of the genetic algorithm with the Branch-and-Bound simulations were performed with four di®erent planting areas and number of varieties, simulating real situations in the geographical region worked. The results were analyzed and discussed in this text, showing that the genetic algorithm can be an alternative tool and very useful for large problems

Orientador: Paulo S. Graziano Magalhães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-10T17:13:32Z (GMT). No. of bitstreams: 1 Baldo_RodrigoFernandoGalzerano_M.pdf: 847065 bytes, checksum: 5e6b7505ee91e4092e5df6b231724a26 (MD5) Previous issue date: 2007 / Resumo: Um dos problemas encontrados na colheita mecanizada da cana-de-açúcar é a falta de sincronismo entre a colhedora e o transbordo, ocasionando perdas tanto de material como de capacidade operacional. A presente pesquisa teve como objetivo desenvolver um sistema capaz de auxiliar no sincronismo entre a colhedora e o veículo de transbordo através de comunicação sem fio utilizando radio freqüência. Dois sensores de ultra-som acoplados ao elevador da colhedora de cana-de-açúcar e um microprocessador, gerenciam tais informações gerando correta sincronia entre as máquinas. O sistema foi testado em laboratório e em campo cumprindo corretamente a função de manter as máquinas em sincronia, indicando e alertando aos operadores as suas posições relativas. O sistema desenvolvido reduziu as perdas de rebolo em cerca de 60 kg ha-1 comparado com a colheita realizada com o sistema desligado, além de melhorar o rendimento operacional da colhedora / Abstract: One of the problems found in mechanical harvesting of sugar cane is the lack of synchronism between the harvester and the infield wagon, causing crop losses as well as reducing the operational capacity. The objective of the present research was to design a system capable to synchronize the sugar cane harvester with the wagon. The communication between tractor and harvester is wireless. The designed system allows the machinery to keep their alignment. The communication among them such us relative position, beginning and end of the harvest line is by radio frequency. Two ultrasound sensors, coupled to the elevator and a microprocessor manage such information generating a correct synchronization among the machines. The system was tested at laboratory and field performing its function adequately, maintaining the two machines in synchronization, indicating and alerting to the operators their relative positions. The developed system reduced the sugar cane lost in 60 kg ha-1 comparing with a harvest with the system turned off and improved the operational capacity of the harvester / Mestrado / Maquinas Agricolas / Mestre em Engenharia Agrícola

Thesis (PhD (Logistics))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Computerised sugarcane harvest scheduling decision support is an active fi eld of research which ties in closely with the broader problem of automating and streamlining the various activities in the sugar supply chain. In this dissertation, the problem of providing decision support with respect to sugarcane harvesting decisions is defined within a number of contexts, each representing a typical kind of organisation of sugarcane farmers into a cohesive decision making unit with its speci fic requirements and limitations that exist in practice. A number of variations relevant to these contexts of an overarching tactical sugarcane harvest scheduling problem (THSP) are considered and solved in this dissertation. The THSP is the problem of providing objective, responsible decision support to persons charged with the task of determining optimal harvesting dates for a set of sugarcane fields across an entire season. Sugarcane fields typically diff er in terms of the age, variety, life-cycle stage and in many other properties of the cane grown on them. The growth of sugarcane crops may also be a ffected by environmental conditions such as accidental fires, frosts or storms which have a detrimental e ffect on crop-value. Since sugarcane is a living organism, its properties change over time, an so does the potential pro t associated with it. The practicalities of farming cause further complication of the problem (for example, seasonal changes alter the conditions under which the crop is harvested and transported). The rainy season carries with it the added cost of disallowing long-range vehicles to drive into the fields, forcing the unloading and reloading of cane at so-called loading zones. Other considerations, such as the early ploughing out of fields to allow them to fallow before being replanted, compounds the THSP into a multi-faceted difficult problem requiring efficient data management, mathematical modelling expertise and efficient computational work. In the literature the THSP has been viewed from many different standpoints and within many contexts, and a variety of operations research methodologies have been employed in solving the problem in part. There is, however, no description in the literature of a solution to the THSP that takes the negative e ffects of extreme environmental conditions on the quality of a harvesting schedule into account in a scienti fically justifi able manner; most models in the literature are based on optimising sucrose yield alone under normal conditions, rendering weak schedules in practice. The scope of the modelling and solution methodologies employed in this dissertation towards solving the THSP is restricted to integer programming formulations and approximate solution methods. The parameters associated with these models were determined empirically using historical data, as well as previous work on deterioration of sugarcane following environmental and other events. The THSP is solved in this dissertation by designing a generic architecture for a conceptual decision support system (DSS) for the THSP in the various contexts referred to above, which is capable of accommodating the e ects of extra-ordinary environmental conditions, as well as the introduction of a computer-implemented version of a real DSS for the THSP conforming to the framework of this generic architecture. The DSS building blocks include prediction models for sugarcane yield, sugarcane recoverable value under normal circumstances, the costs associated with a harvesting schedule and the negative e ects on sugarcane recoverable value of extraordinary environmental conditions. The working of the DSS is based on a combinatorial optimisation model resembling the well-known asymmetric traveling salesman problem with time-dependent costs which is solved approximately by means of an attribute-based tabu search in which both local and global moves have been incorporated. The DSS is also validated by experienced sugarcane industry experts in terms of the practicality and quality of the schedules that it produces. / AFRIKAANSE OPSOMMING: Gerekenariseerde besluitsteun vir die skedulering van suikerriet-oeste is 'n aktiewe navorsingsveld wat nou verwant is aan die bre ër probleem van die outomatisering en vaartbelyning van 'n verskeidenheid aktiwiteite in die suikervoorsieningsketting. Die probleem van die daarstelling van steun rakende suikkerriet oestingsbesluite word in hierdie proefskrif in 'n aantal kontekste oorweeg, elk met betrekking tot 'n tipiese soort organisasie van suikerrietboere in 'n samehorige besluitnemingseenheid met sy spesi eke vereistes en beperkings in die praktyk. Verskeie variasies van 'n oorkoepelende taktiese suikerriet-oesskeduleringsprobleem (TSOSP) wat in hierde kontekste relevant is, naamlik die probleem om objektiewe, verantwoordbare steun aan besluitnemers te bied wat verantwoordelik is vir die bepaling van optimale oesdatums vir 'n versameling suikerrietplantasies oor die bestek van 'n hele seisoen, word in hierdie proefskrif bestudeer en opgelos. Suikerrietplantasies verskil tipies in terme van ouderdom, gewastipe, posisie in die lewensiklus, en vele ander eienskappe van die suikerriet wat daar groei. Omgewingstoestande, soos onbeplande brande, ryp of storms, het verder ook 'n negatiewe impak op die waarde van suikerriet op sulke plantasies. Omdat suikerriet 'n lewende organisme is, verander die eienskappe daarvan oor tyd, en so ook die potensi ele wins wat daarmee geassosieer word. Boerderypraktyke bemoeilik verder die skeduleringsprobleem onder beskouing (seisoenale veranderings beïnvloed byvoorbeeld die wyse waarop suikerriet ge-oes en vervoer word). Addisionele koste gaan voorts met die re ënseisoen gepaard, omdat die plantasies dan nie toeganklik is vir langafstand transportvoertuie nie en suikerriet gevolglik na spesiale laaisones gekarwei moet word voordat dit op hierdie voertuie gelaai kan word. Ander oorwegings, soos die vroe ë uitploeg van plantasies sodat die grond kan rus voordat nuwe suikerriet aangeplant word, veroorsaak dat die TSOSP 'n moeilike multi-faset probleem is, wat goeie databestuur, wiskundige modelleringsvernuf en doeltreff ende rekenaarwerk vereis. Die TSOSP word in die literatuur vanuit verskillende standpunte en in verskeie kontekste oorweeg, en 'n aantal uiteenlopende operasionele navorsingsmetodologie ë is al ingespan om hierdie probleem ten dele op te los. Daar is egter geen poging in die literatuur om 'n oplossing vir die TSOSP daar te stel waarin daar op 'n wetenskaplik-verantwoordbare wyse voorsiening gemaak word vir die negatiewe e ffekte wat uitsonderlike omgewingstoestande op die kwaliteit van oesskedules het nie; die meeste modelle in die literatuure is op slegs sukrose-opbrengs onder normale omstandighede gebaseer, wat lei na swak skedules in die praktyk. Die bestek van die wiskundige modellerings- en gepaardgaande oplossings-metodologie ë word in hierdie proefskrif vir die TSOSP beperk tot onderskeidelik heeltallige programmeringsformulerings en die bepaling van benaderde oplossings deur lokale soekprosedures. Die parameters wat met hierdie modelle en soekmetodes geassosieer word, word empiries bepaal deur gebruikmaking van historiese data asook bestaande werk oor die degradering van suikerriet as gevolg van omgewings- en ander eksterne faktore. Die TSOSP word in hierdie proefskrif opgelos deur die ontwerp van 'n generiese argitektuur vir 'n konseptuele besluitsteunstelsel (BSS) vir die TSOSP in die onderskeie kontekste waarna hierbo verwys word en wat die e ekte van uitsonderlike omgewingsfaktore in ag neem, asook die daarstelling van 'n rekenaar-ge ïmplementeerde weergawe van 'n daadwerklike BSS vir die TSOSP wat in die raamwerk van hierdie generiese argitektuur pas. Die boustene van hierdie BSS sluit modelle in vir die voorspelling van suikerrietopbrengs, die herwinbare waarde van suikerriet onder normale omstandighede, die verwagte koste geassosieer met 'n oesskedule en die negatiewe e ekte van omgewingsfaktore op die herwinbare waarde van suikerriet. Die werking van die BSS is gebaseer op 'n kombinatoriese optimeringsprobleem wat aan die welbekende asimmetriese handelreisigersprobleem met tyd-afhanklike kostes herinner, en hierdie model word benaderd opgelos deur middel van 'n eienskap-gebaseerde tabu-soektog waarin beide lokale en globale skuiwe ge ïnkorporeer is. Die BSS word ook gevalideer in terme van die haalbaarheid en kwaliteit van die skedules wat dit oplewer, soos geassesseer deur ervare kundiges in die suikerrietbedryf.

Orientador: Helenice de Oliveira Florentino Silva / Banca: Adriana Cristina Cherri / Banca: Fernando Luiz Pio dos Santos / Resumo: O objetivo deste trabalho é propor um modelo matemático que consiste em determinar quais variedades de cana-de-açúcar adaptável ao solo local serão plantadas nos talhões disponíveis de forma a obter o menor custo possível para o processo de colheita e transporte da cana, e ainda desenvolver e testar um algoritmo genético (AG) para investigar a solução deste problema. Inicialmente é feito um breve estudo do ciclo produtivo da cana-de-açúcar, dos prazos para a eliminação de sua queima e do custo, de sua colheita e transporte até a usina. Em seguida estuda-se o algoritmo Branch-and-Bound, o qual dentre os métodos exatos é bastante utilizado para resolver Problemas de Programação Linear Inteira (PPLI). Para testar e comparar a performance do algoritmo genético com o Branch-and-Bound foram realizadas quatro simulações com diferentes áreas de plantio e número de variedades, simulando situações reais na região geográfica trabalhada. Os resultados foram analisados e discutidos neste texto, mostrando que o algoritmo genético pode ser uma ferramenta alternativa e de grande utilidade para problemas de grande porte / Abstract: The objetive of this study is to propose a mathematical model that consist of determining which varieties of sugar cane adaptable to local soil should be planted in plots available in order to obtain the lowest cost to the process of harvesting and transportation of cane, and further develop and test a genetic algorithm (GA) to investigate the solution of this problem. Initially it has been done a short study of the production cycle of sugar cane, the deadline for the elimination of his burns and the cost of harvest and transport to the mill. In the next step, we studied the algorithm Branch-and-Bound, which among methods available is often employed to solve Integer Linear Programming Problems (PPLI). To test and compare the performance of the genetic algorithm with the Branch-and-Bound simulations were performed with four di®erent planting areas and number of varieties, simulating real situations in the geographical region worked. The results were analyzed and discussed in this text, showing that the genetic algorithm can be an alternative tool and very useful for large problems / Mestre

The South African sugar industry is of significant local and international importance and covers an area in excess of 450 000 hectares. This area yields approximately 21 million tons of sugarcane per annum which is transported almost exclusively by road, from farms to the sugar mills. The industry is under increasing economic pressures to improve its productivity and competitiveness and sugarcane transport in the sugarcane supply chain has been identified as one area where large improvements and associated cost reductions can be made. This is mainly due to the excess in number of vehicles in the inbound transport system, the high relative cost of transport compared to other production costs in producing sugarcane, and the high fixed costs associated with truck fleet operations. A simulation case study of the transport system was completed in 2005 in the Sezela Mill area in which approximately 2.2 million tons of sugarcane is transported per annum over an average distance of 29 km by approximately 120 independently managed vehicles owned by a wide range of hauliers and individual growers. This amounts to an estimated cost of R58 million per annum. This study investigated the potential savings that could occur as a result of a central fleet control system with integrated vehicle scheduling. A scheduling software package named ASICAM, which resulted in significant savings in the timber industry (Weintraub et al, 1996), was applied within the Sezela region. Results suggested that the number of trucks in the fleet could theoretically be reduced by at least 50%, providing that a central office controls vehicle movements and that all hauliers serve all growers in an equitable fashion. In addition, investigations towards decreasing loading times, decreasing offloading times, changing vehicle speeds and increasing payloads by reducing trailer tare mass showed further reductions in the number of trucks required. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Long delays between harvesting and crushing of sugarcane lead to excessive deterioration in the quality of sugarcane. The aim of this project was to develop a computer based model of sugarcane harvesting and delivery systems that could be used to investigate methods of reducing harvest-to crush delays. A literature review was conducted and simulation modelling was chosen as the most appropriate modelling technique for the situation of sugarcane harvesting and delivery and the purposes of this project. The Arena modelling system was chosen as the simulation software with which to construct the model. A model was developed on the scale of a particular sugar mill and the area of farms supplying it with cane. The Sezela mill on the south coast of KwaZulu-Natal, South Africa was chosen as a case study on which to develop and test the model. The model integrated a harvesting and transport section which represented all the individual farms or combinations of farms in the area with a millyard section. After the model had been verified and validated, it was used to investigate the effect of a number of different scenarios of harvesting and delivery systems and schedules on harvest-to-crush delays in the Sezela mill area. The results of the experimental runs performed with the model indicated that the most significant decreases in harvest-to-crush delays could be brought about by matching harvesting, delivery and milling cycles as closely as possible. It was also evident that burn-to-cut delays where daily burning is not practised constitute a large proportion of overall harvest-to crush delays. The model proved to be useful in making comparisons between systems and in providing a holistic view of the problem of harvest-to-crush delays. Recommendations for future developments of the model include adding a mechanical harvesting component and making the model more easily applicable to other mill areas. / Thesis (M.Sc.Eng.)-University of Natal, 1998.

Submitted by GUILHERME DE CASTRO BELARDO null (guibelardo@terra.com.br) on 2017-01-09T13:24:50Z No. of bitstreams: 1 Tese_Guilherme_de_Castro_Belardo.pdf: 2624976 bytes, checksum: 61051d51c27fa21539b3d4e6fc315b25 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-01-11T18:39:59Z (GMT) No. of bitstreams: 1 belardo_gc_dr_jabo.pdf: 2624976 bytes, checksum: 61051d51c27fa21539b3d4e6fc315b25 (MD5) / Made available in DSpace on 2017-01-11T18:39:59Z (GMT). No. of bitstreams: 1 belardo_gc_dr_jabo.pdf: 2624976 bytes, checksum: 61051d51c27fa21539b3d4e6fc315b25 (MD5) Previous issue date: 2016-08-05 / Avaliação de desempenho de colhedoras multilinhas de cana-de-açúcar em três espaçamentos. A tese foi subdividida em seis capítulos sendo: Capitulo 1: Considerações Gerais. Capitulo 2: Metodologia utilizada nos ensaios. Capitulo 3: Desempenho de três colhedoras de cana-de-açúcar em espaçamento duplo alternado. Capitulo 4: Desempenho de duas colhedoras de cana-de-açúcar em espaçamento duplo alternado em duas condições de canaviais. Capitulo 5: Desempenho de colhedoras de cana-de-açúcar em colheita de duas fileiras de espaçamentos simples de 1,5m e e triplo alternado (0,75 x 0,75 x 1,5m). Capitulo 6: Considerações Finais.