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<p>    </p> <p>An energy harvesting system (EHS) provides the intriguing possibility of battery-less computing and enables various applications such as wearable, industrial or environmental sensors, and im- plantable medical devices. The biggest challenge of EHS is the instability of energy sources (e.g., Wi-Fi, solar, thermal energy, etc.) which causes unpredictable and frequent power outages. To address the challenge, existing works introduce software-based and hardware-based power failure recovery solutions that ensure program correctness across a power outage. However, they cause a significant performance overhead without providing the high quality of service in reality, and suffer from a reliability issue. In this dissertation, we address the limitations of recovery solutions across the system stack, from the compiler-directed approach and run-time systems to hardware mechanisms, and demonstrate the effectiveness of the approaches using real EHS platforms and simulators. We first present software-based recovery solutions by leveraging compiler support. We develop a compiler-directed solution built upon commodity EHS platform that can achieve 3X speedup compared to the software-based state-of-the-art solution. We also introduce a compiler optimization technique that can cooperate with run-time systems and hardware support, achieving 8X speedup compared to the software-based solution. We then present hardware-based recov- ery solutions by leveraging compiler and hardware support. We develop an architecture/compiler co-design solution that re-purposes existing hardware components in a core for power failure spec- ulative execution, a new speculation paradigm, and leverages a novel compiler analysis for cor- rect power failure recovery. Our result highlights 2 ∼ 3x performance improvement compared to the hardware-based state-of-the-art solution without requiring hardware modification. Next, we present a new cache design for EHS that can achieve cost-effective, high-performance intermit- tent computing. According to experimental results, the new cache design outperforms the state- of-the-art cache scheme by 4X and reduces the hardware cost by 90%. Finally, we present an operating system (OS)-driven solution to address a reliability problem on EHS devices while all existing works are vulnerable, causing the wrong recovery across power failure. Our experiments demonstrate that the solution causes less than 1% run-time overhead and successfully addresses the reliability problem without compromising correct power failure recovery. </p>

The limitation of urban water supplies is becoming worse each year. Several studies estimate that 2 billion of the world’s population will suffer from water scarcity by 2050; and urbanization rates is placing an even greater challenge in providing the infrastructure needed to serve growing populations. At this point, rainwater may be considered as the most critical, untapped water resource in a global aspect. Rainwater Harvesting Systems (RWHS) have tremendous potential, not only to provide sufficient water supply, but also to serve as a valuable stormwater management tool. Despite these benefits, RWHS is still not popular among ordinary people in urban situations, due mostly to high installation costs. This study aims to explore the equitable cost reallocation of residential rainwater harvesting systems between the urban utility, land developer and homebuilder, and individual homeowner sectors. It may be possible to redistribute the cost equitably among the parties based on potential benefits received,thereby making RWHS more affordable and more viable as a new water supply for urban areas. / text

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The impact of harvesting systems and laborer platforms on fruit quality were assessed when harvesting, as well as laborer productivity when performing orchard actions requiring the use of ladders. Harvesting systems and laborer platforms were compared to conventional labor practices. Trials were done on stone and pome fruit farms throughout the Western Cape. Harvesting systems showed potential to decrease bruising on hardy apple cultivars such as Red Chief and Cripps’ Red. However, similar or even higher injury levels were obtained on more sensitive cultivars such as Golden Delicious and Cripps’ Pink. Conventional teams incur little bruising on the hardier cultivars, thus the scope of improvement on these cultivars is small. Conventional teams incur higher injury levels on more sensitive cultivars, leaving much room for improvement. However, due to high harvesting injury levels incurred by teams on the harvesting systems, no improvement was obtained. Conventional teams achieve very high picking productivity outputs for hardy cultivars like Abate Fetel, Red Chief and Cripps’ Red whereas outputs are lower for sensitive cultivars like Golden Delicious and Cripps’ Pink. Harvesting systems reached an upper limit of around 150 kg per picker per hour when strip picking, regardless of cultivar hardiness. This limit stemmed from the misalignment between orchard and machine design, which results in a very inefficient picking action. This limits the number of picking cycles that can be completed in a certain amount of time, which in turn limits the weight of fruit that can be picked in that time. Furthermore, factors such as tree size, shape and uniformity, fruit distribution on the tree, fruit size and quality, orchard floor condition and aspect, labor team dynamics, harvesting incentives, bin condition, operational system employed and harvest logistics all affected the overall productivity and efficiency of the harvesting systems. When performing summer pruning with the aid of a laborer platform, productivity was substantially increased compared to conventional laborers on ladders. Dormant pruning and fruit thinning with laborer platforms also showed potential for increased laborer productivity. The extent of improvement was smaller than for summer pruning and was dependent on the pruning/ thinning strategy employed as well as tree architecture. In general, narrower and younger trees showed larger increases in productivity. Producers should aim to simplify pruning and thinning strategies in order to maximize productivity gains when using laborer platforms while at the same time maintaining good fruit quality and yield. Our study revealed that laborer platforms can increase laborer productivity for certain orchard tasks but substantial gains in harvesting productivity through mechanization is not a possibility in the near future. Our study did, however, allude to the potential gains in productivity that can be made with more efficient management and implementation of conventional harvesting practices. Producing, and more specifically, harvesting deciduous fruit for the fresh market will likely remain a labor intensive process. Therefore it is important that producers focus on investing in labor-related factors such as laborer training, motivation and satisfaction together with the careful implementation of new technologies such as laborer platforms. / AFRIKAANSE OPSOMMING: Die impak van oesstelsels en arbeider-platforms op vrugkwaliteit tydens oes sowel as arbeider produktiwiteit met die uitvoer van boordtake waar traplere gebruik word, is geevalueer. Die oesstelsels en arbeider-platforms is vergelyk met konvensionele praktyke wat op verskeie steen- en kernvrugplase in die Wes-Kaap gebruik word. Oesstelsels het die potensiaal om appel kultivars met 'n lae beseringsgevoeligheid, soos Red Chief en Cripps’ Red minder te kneus. Soortgelyke of selfs hoër vlakke van oesbeserings is waargeneem op sensitiewe kultivars soos Golden Delicious en Cripps’ Pink. Konvensionele plukspanne handhaaf oor die algemeen lae vlakke van oesbeserings op geharde kultivars, wat min ruimte vir verbetering laat. Oesbeserings vir konvensionele spanne op sensitiewe kultivars is egter hoog en laat baie ruimte vir verbetering, maar weens die hoë vlakke van beserings van die spanne op die oesstelsels, is geen verbetering waargeneem nie. Konvensionele plukspanne handhaaf hoë oesproduktiwiteit uitsette op geharde kultivars soos Abate Fetel, Red Chief en Cripps’ Red terwyl oesproduktiwiteit vir sensitiewe kultivars soos Golden Delicious en Cripps’ Pink laer is. Oesstelsels het 'n maksimum plukuitset van 150 kg per plukker per uur behaal tydens skoon-pluk, ongeag kultivar gehardheid. Hierdie beperking ontstaan as gevolg van die onverenigbaarheid tussen boord- en masjienontwerp wat tot 'n baie ondoeltreffende plukaksie lei vir die plukkers. Die onverenigbaarheid beperk die aantal plukbewegings wat 'n plukker kan voltooi binne 'n sekere tyd wat weer die totale massa van die vrugte wat in daardie tyd gepluk word beperk. Boomgrootte, -vorm en –uniformiteit, vrugverspreiding op die boom, vruggrootte en – kwaliteit, toestand en helling van die boordvloer, arbeiderverhoudings, plukker vergoeding, krattoestand, operasionele stelsels wat geïmplementeer word en die organisering van oestyd logistiek het 'n invloed gehad op die produktiwiteit uitsette wat met die oesstelsels behaal is. Die gebruik van 'n arbeider-platform vir somersnoei het arbeider produktiwiteit beduidend verhoog in vergelyking met konvensionele arbeiders op traplere. Wintersnoei en vruguitdunning met arbeider-platforms het ook die potensiaal om arbeider produktiwiteit te verhoog. 'n Kleiner verhoging in produktiwiteit as by somersnoei is waargeneem en het afgehang van die snoei- of uitdun-strategie sowel as boom argitektuur. Oor die algemeen het jonger en smaller bome groter verhogings in produktiwiteit getoon. Ten einde maksimum voordeel te geniet met die gebruik van arbeider-platforms moet produsente poog om snoei- en uitdun-strategieë te vereenvoudig terwyl goeie vrugkwaliteit en opbrengs gehandhaaf word. Ons navorsing het getoon dat die gebruik van arbeider-platforms, arbeider produktiwiteit vir sekere boord-take kan verhoog, maar 'n beduidende toename in oesproduktiwiteit d.m.v. meganisasie blyk nie 'n moontlikheid te wees in die nabye toekoms nie. Ons navorsing het wel gedui op die potensiële toenames in oesproduktiwiteit wat verkry kan word met meer doeltreffende bestuur en implementering van huidige konvensionele stelsels. Die verbou, en meer spesifiek die oes van sagtevrugte vir die varsproduktemark sal waarskynlik 'n arbeidsintensiewe proses bly. Daarom is dit belangrik dat produsente aandag gee aan die opleiding, motivering en bevrediging van arbeiders saam met die implementering van nuwe tegnologie soos arbeider-platforms.

Orientador: Marcílio Vieira Martins Filho / Banca: Zigomar Meneses de Souza / Banca: José Luiz Rodrigues Torres / Banca: Afonso Lopes / Banca: Maria Ignez Espagnoli Geraldo Martins / Resumo: O objetivo geral deste trabalho foi demonstrar o valor econômico das perdas de nutrientes por erosão do solo, no cultivo da cana-de-açúcar. Especificamente, avaliar as perdas de nutrientes por erosão (P, K, Ca e Mg), o custo de reposição de nutrientes e de produção da cana, e os indicadores de análise de investimentos: valor presente líquido, taxa interna de retorno e a relação benefício / custo em dois sistemas de colheita (cana crua e queimada) em Catanduva - SP, em área de 100 ha para cada sistema, formadas e colhidas no mesmo período de (2002 a 2007), com similaridade quanto ao tipo de solo, variedade, topografia e número de cortes. A metodologia baseou-se na equação universal da perda de solos, teoria dos custos de produção e de reposição de nutrientes, e teoria dos indicadores das análises de investimentos. Estimou-se que a área com cana queimada perdeu mais nutrientes em todos os cortes, por isso o maior custo médio de reposição de nutrientes R$ 33,93 ha-1 ano-1, sendo de R$ 21,12 ha-1 ano-1 para a cana crua. O menor custo de produção foi da cana crua em todos os cortes, média de R$ 29,60 t-1, sendo de R$ 32,71 t-1 para a queimada. A cana crua apresentou um lucro médio de R$ 5,70 t-1 (R$ 562,87 ha-1 ano-1) e a queimada de R$ 2,59 t-1 (R$ 217,46 ha-1 ano-1). O retorno econômico da cana crua é superior ao da cana queimada, evidenciado ainda mais por meio dos resultados obtidos pelos dois sistemas de colheita, considerando-se índices de análises de investimentos (VPL, TIR, B/C). Conclui-se que a cana crua apresentou o melhor retorno técnico e econômico em virtude de proporcionar melhor conservação do solo e da água, a qual foi valorada pelo custo de reposição de nutrientes perdidos por erosão / Abstract: The general objective of this work was to demonstrate the economic value of nutrients loss by soil erosion in sugarcane cultivation. Specifically, It was to evaluate the nutrient loss through erosion (P, K, Ca and Mg), the cost of replacing the nutrients and the production of sugar cane, and also the indicators of investment analysis: liquid present value, the internal return tax, and the benefit cost relation in two harvesting systems (raw cane and burnt) in Catanduva, São Paulo state, Brazil. An area of 100 ha was studied for each system, formed and harvested in the same period (2002 and 2007), with similarities in the type of soil, variety, topography, and the number of cuts. The methodology was based on the universal equation of soil loss and the theory of production costs and the replacement of nutrients. It was estimated that an area of burnt sugar cane lost more nutrients in all of the cuts, thus it has the highest average cost of replacing the nutrients, BRR$33.93 ha-1 year-1, compared with BRR$21.12 ha-1 year-1 for raw cane. The lowest production cost was with raw cane in all of the cuts, with an average of BRR$29.60 t-1, compared to BRR$32.71 t-1 for burnt cane. Raw cane presents an average profit of BRR$5.70 t-1 (BRR$562.87 ha-1 year-1) and burnt BRR$2.59 t-1 (BRR$217.46 ha-1 year-1). The economic return on raw cane is higher than that of burnt cane, which is proven from the results obtained from the two systems of harvesting through the analysis of the investment indexes (LPV, IRT, B/C). We can conclude that raw cane presents the best technical and economic return in its ability to better conserve soil and water, which is valued in the cost of nutrient replacement and losses through erosion / Doutor

In recent years, the increasing awareness of scarcity of water resources, indications of likely climate variability, and the increasing pressure to use available fresh water resources more efficiently have together reinforced the need to look at infrastructure solutions with due regard to environmental considerations and social impacts, present and future. There is a vital need to apply an integrated approach to catchment management to implement sustainable solutions to resolve issues such as water supply and sewerage, drainage and river flooding. Many potentials solutions are available to control water demand and manage flood problems. Greywater recycling and rainwater harvesting are novel technologies. However, their catchment scale impacts on hydraulic and hydrological flows are poorly understood. The research aim is to identify the hydrologic and hydraulic impacts of scaling up such technologies at catchment scale. For this particular study, a computer simulation model will be used to evaluate how increasing urbanisation, climate change and the implementation of greywater recycling and rainwater harvesting may alter the water balance within a representative catchment. To achieve these aims data from the Carrickmines catchment in Ireland have been collected; a simulation model has been adapted to carry out the study, the model has been calibrated and validated, results have been analysed, and finally, a sensitivity analysis has been carried out. The results show that rainwater harvesting systems are comparatively more effective than greywater recycling techniques in reducing flood frequency and intensity. Under five year return period rainfall events, the implementation of rainwater harvesting at any scale and number of units is a useful technique to control river flow and floods. However, the study also shows that under extreme conditions the efficiency of rainwater harvesting systems decreases. The study concludes that implementing the two technologies within a single catchment is not a solution to several forms of hydrological problem. The study shows that implementing rainwater harvesting or re-use technologies are a very useful way to protect local freshwater reserves and therefore conserve our environment.

Climate change (CC) science has made significant progress in development of predictive models. Despite these recent advances, the assessment of CC impacts in urban watersheds remains an area of active research, in part due to the small temporal and spatial scales needed to adequately characterize urban systems. Urban watersheds have been the focus of considerable efforts to restore hydrology and water quality, and the aquatic habitat of receiving waters, yet CC impacts threaten to reduce the effectiveness of these efforts. Thus, assessing the impacts of CC in urban watershed assessment are essential for assuring the success of water quality improvement programs and is an important research need. Simulations of CC for the 2041-2068 period were developed using downscaled Global Climate Models (GCMs) from the North American Regional CC Assessment Program (NARCCAP) and Coupled Model Intercomparison Project Phase 5 (CMIP5) to forecast precipitation and temperature time series. This data were then used to force a Storm Water Management Model (SWMM) of the Difficult Run watershed of Fairfax County, Virginia, a tributary of Potomac River, which flows into Chesapeake Bay. NARCCAP uses a scenario represents a medium-high greenhouse gas emissions assumption, A2; the latter, uses five GCMs, and two Representative Concentration Pathways (RCP 4.5 and 8.5) scenarios in an ensemble approach to better assess variability of model predictions in presenting precipitation, temperature, runoff quantity and quality. Then, the effects of CC on runoff peak, volume, and nutrient and sediment loads delivered to the Chesapeake Bay and on the treatment performance of a very common stormwater control measure (SCM), retention ponds, was assessed. Rainwater Harvesting (RWH) systems are an unusual SCM in that they recycle and reuse stormwater, normally from rooftops, and increase water supply and reduce runoff. The efficiency of RWH systems for projected CC for these dual purposes was assessed. NARCAAP data for selected locations across the U.S. were statistically downscaled using a modified version of the equiratio cumulative distribution function matching method to create a time series of projected precipitation and temperature. These data were used to force a simulation model, the Rainwater Analysis and Simulation Program (RASP) to assess the impacts of CC on RWH with respect to the reliability of water supply and runoff capture. To support CC modeling, an easy-to-use software tool, RSWMM-Cost, was developed. RSWMM-Cost automates the execution of SWMM, which is commonly used for simulating urban watersheds. Several features were incorporated into the RSWMM-Cost tool, including automated calibration, sensitivity analysis, and cost optimization modules; the latter can assist in identifying the most cost-effective combination of SCMs in an urban watershed. As an example, RSWMM-Cost was applied to a headwater subcatchment the Difficult Run watershed. / Ph. D. / Urban watersheds have been the focus of considerable efforts to restore water quantity and quality, and the aquatic habitat of receiving waters, yet climate change impacts threaten to reduce the effectiveness of these efforts. The assessment of climate change impacts in urban watersheds remains an area of active research, in part due to the small temporal and spatial scales needed to adequately characterize urban systems. Thus, assessing the impacts of climate change in urban watershed assessment are essential for assuring the success of water quality improvement programs and is an important research need. In this study, simulations of climate change for the 2041-2068 period were developed to forecast precipitation and temperature data. These data were then used to force a hydrologic model for the Difficult Run watershed of Fairfax County, Virginia, a tributary of Potomac River, which flows into Chesapeake Bay. Then, the effects of climate change on runoff, nutrient and sediment loads delivered to the Chesapeake Bay and on the treatment efficiency of a very common management practice called retention ponds, was assessed. Rainwater harvesting systems are an unusual management practice that recycle and reuse stormwater, normally from rooftops, and increase water supply and reduce runoff. The efficiency of rainwater harvesting systems for projected climate change with respect to the reliability of water supply and runoff capture was assessed for the 2041-2068 period. To support climate change modeling, an easy-to-use tool, was also developed to select the most cost-optimized combination of best management practices in urban watersheds considering site constraints, limitations, and size. As an example, the tool was applied to a headwater subcatchment of the Difficult Run watershed. The ability to assess the impact of climate change on both hydrologic and water quality treatment could assist in the selection of the most appropriate management practices to address water management goals and conserve limited financial resources.

Due to climate change, water resources’ scarcity and distribution variability have generated a growing interest in sustainable water management in recent years. In addition, the growing interest in implementing nature-based solutions for urban resilience leads to the development of decentralized water supply systems such as rainwater harvesting systems (RWHS) as a complementary resource to conventional centralized water supply systems. The study is motivated by the climatic risks that the city of Madrid is subject to face in the upcoming years such as pronounced summer droughts and urban heat waves, leading to the reduction of water resources availability. This study aims to use Multi-criteria decision analysis and Geographic Information systems as tools for locating optimal space for the installation of pond harvesting systems (PHS) in Madrid for water recollection for non-potable purposes in the city. Attaining this aim, two objectives were set. Firstly, to evaluate and select the most relevant criteria for the installation of PHS and secondly, to generate a map of the most suitable locations for installation of PHS in the city of Madrid through a proposed GIS-MCDA methodology and a complimentary evaluation for each possible solution, to obtain a global vision of the applicability of PHS in Madrid. Through the first objective, several criteria were set for PHS installation, namely: distance to the river, rainfall, slope, soil characteristics, and land use. These criteria were applied to Madrid through a GIS-MCDA methodology, using these two tools’ synergy to obtain a suitability map for PHS installation. Two criteria weightings will be performed to evaluate the model’s robustness by modifying the criteria’ weights resulting in two different suitability scenarios. The discussion will analyze the results obtained considering the two scenarios and propose the most suitable location clusters identified. Finally, the conclusion will reflect the study’s most important findings and open the door to further research on the topic, such as the design, operation infrastructure, drainage logistics distribution, and other modifications in Madrid’s current water management system. / Som en konsekvens av den pågående klimatförändringen och dess inverkan i distributionen av vattenresurser har det skapats ett växande intresse för en hållbar vattenförvaltning de senaste åren. Detta växande intresse leder till implementationen av naturbaserade lösningar för urban resiliens och till en utveckling av decentraliserade vattenförsörjningssystem som regnvattenuppsamling (RWHS) som en komplementerande resurs till konventionella centraliserade vattenförsörjningssystem. Huvudsyftetmed denna studie är att täcka forskningsklyftan och att genom användning av verktyg som multikriterieanalys och geografiskt informationssystem (GIS) lokalisera en optimal plats för installation av dammar för regnvattenupptagning som del av stadsplanering för att skapa en hållbar vattenförvaltning i staden. För att uppnå detta, sattes två mål. Det ena var att utvärdera och välja de mest relevanta kriterierna för installation av dammuppsamlingssystem (PHS), det andra målet var att generera en karta över de lämpligaste platserna för installation av PHS i Madrid (Spanien) genom en föreslagen GIS-MCDA-metod och en kompletterande utvärdering för varje möjligt resultat i syfte att få en global vision av tillämpligheten av PHS i Madrid. De främsta kriterierna som utsågs för att göra utvärderingen av uppsamlingssystems installationen var: avstånd till f loden, nederbörd, sluttning, markegenskaper och markanvändning. Dessa kriterier tillämpades genom en GIS-MCDA-metodik, och med hjälp av dessa verktygs synergi erhölls en lämplighetskarta för PHS-installationer. Två kriterie viktningar kommer att utföras för att utvärdera modellens robusthet och vilket även kommer att resultera i två olika lämplighetsscenarier. Diskussionen kommer bestå av en analys av resultaten med hänsyn till de två scenarierna, och föreslå de två lämpligaste lokaliseringsklustren som identifierats. Slutligen kommer slutsatsen att återspegla studiens viktigaste resultat och öppna dörren för ytterligare forskning i ämnet, såsom design, driftinfrastruktur, dräneringslogistikdistribution och andra modifieringar i Madrids nuvarande vattenledningssystem.

abstract: Recently, nanostructured metamaterials have attracted lots of attentions due to its tunable artificial properties. In particular, nanowire/nanohole based metamaterials which are known of the capability of large area fabrication were intensively studied. Most of the studies are only based on the electrical responses of the metamaterials; however, magnetic response, is usually neglected since magnetic material does not exist naturally within the visible or infrared range. For the past few years, artificial magnetic response from nanostructure based metamaterials has been proposed. This reveals the possibility of exciting resonance modes based on magnetic responses in nanowire/nanohole metamaterials which can potentially provide additional enhancement on radiative transport. On the other hand, beyond classical far-field radiative heat transfer, near-field radiation which is known of exceeding the Planck’s blackbody limit has also become a hot topic in the field. This PhD dissertation aims to obtain a deep fundamental understanding of nanowire/nanohole based metamaterials in both far-field and near-field in terms of both electrical and magnetic responses. The underlying mechanisms that can be excited by nanowire/nanohole metamaterials such as electrical surface plasmon polariton, magnetic hyperbolic mode, magnetic polariton, etc., will be theoretically studied in both far-field and near-field. Furthermore, other than conventional effective medium theory which only considers the electrical response of metamaterials, the artificial magnetic response of metamaterials will also be studied through parameter retrieval of far-field optical and radiative properties for studying near-field radiative transport. Moreover, a custom-made AFM tip based metrology will be employed to experimentally study near-field radiative transfer between a plate and a sphere separated by nanometer vacuum gaps in vacuum. This transformative research will break new ground in nanoscale radiative heat transfer for various applications in energy systems, thermal management, and thermal imaging and sensing. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2017

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-16T20:24:26Z No. of bitstreams: 1 CLAYTON MOURA DE CARVALHO - DISSERTAÇÃO PPGEA 2003..pdf: 7009655 bytes, checksum: e0dd3bdd2dcfb837728bbdfced031a99 (MD5) / Made available in DSpace on 2018-10-16T20:24:26Z (GMT). No. of bitstreams: 1 CLAYTON MOURA DE CARVALHO - DISSERTAÇÃO PPGEA 2003..pdf: 7009655 bytes, checksum: e0dd3bdd2dcfb837728bbdfced031a99 (MD5) Previous issue date: 2003-12 / Em zonas áridas e semi-áridas, como no Nordeste brasileiro, onde geralmente ocorre o fenómeno natural da seca, a utilização da irrigação é uma das poucas opções quando não a única, para assegurar a produção agrícola sustentável, principalmente se associada à prática da adubação. Com o objetivo de se estudar o comportamento da cana-de-açúcar terceira folha (Saccharum officinarium L., variedade SP 791011), sob diferentes níveis de irrigação e dois níveis de adubação de cobertura, instalou-se um experimento na fazenda Capim, da Destilaria Miriri, no município de Capim, PB. O experimento foi realizado através de uma análise fatorial do tipo 2x4 (dois níveis de adubação de cobertura, No e Ni, e quatro níveis de irrigação, Wo, Wi, W2 e W3) com três repetições, totalizando 24 diferentes combinações. Os níveis do fator adubação de cobertura foram N0 = 72 kg ha'1 (28 kg ha"1 de nitrogénio e 44 kg ha"1 de potássio) e Ni = 276 kg ha'1 (112 kg ha"1 de nitrogénio e 164 kg ha" de potássio). A adubação de cobertura foi aplicada de uma única vez. Os níveis do fator irrigação foram Wo = 0; Wi = 152; W2 = 290 e W3 = 393 mm. A aplicação de água foi feita através de um sistema de irrigação tipo pivô central rebocável, em turnos de 12 dias, e o cálculo da evapotranspiração foi com base no tanque "classe A", subtraindo a precipitação efetiva. As quantidades totais de água aplicada (irrigação mais precipitação efetiva) foram W0 = 275; Wi = 927; W2 = 1.065 e W3 = 1.168 mm. Entre os parâmetros de crescimento estudados, o número de colmos, o diâmetro dos colmos e o número de internódios e nenhum dos parâmetros tecnológicos não foram influenciados pelos tratamentos analisados. O número máximo de colmos por hectare foi de 94.630 (dado pelo tratamento W3 = 1.168 mm e Ni = 276 kg ha"1), o qual foi superior ao limite mínimo ideal de 90.000 colmos ha"1 apresentado na literatura para se obter produtividades máximas. A produção de colmos e a produtividade de açúcar e de álcool foram influenciados significativamente pelos fatores adubação de cobertura e irrigação, mas não significativamente pela interação adubação de cobertura versus irrigação. A produção média de colmos obtida no experimento foi de 82,66 t ha"1, a menor de 68,44 t ha"1 (dada pelo tratamento Wo = 775 mm e Ni = 276 kg ha" x) e a maior 103,09 t ha"1 (dada pelo tratamento W3 = 1.168 mm e Ni = 276 kg ha"1). A produção média de açúcar bruto foi de 12,29 t ha"1, a menor de 9,68 t ha"1 (dada pelo tratamento W0 = 775 mm e Nc = 72 kg ha"1) e a maior de 15,29 t ha"1 (dada pelo tratamento W3 = 1.168 mm e Ni = 276 kg ha"1). A produção média de álcool bruto foi de 8,74 m3 ha"1, a menor de 6,89 m3 ha"1 (dada pelo tratamento W0 = 775 mm e No = 72 kg ha"1) e a maior de 10,88 m3 ha"1 (dada pelo tratamento W3 =1.168 mm e Ni = 276 kg ha"1). Houve acréscimo na produção média dos colmos e na produtividade de açúcar e de álcool, com o aumento do nível de irrigação no tratamento com maior quantidade de adubação de cobertura. / In arid and semi-arid áreas, like in the Brazilian Northeast region, where the natural phenomenon of drought usually happens, the use of the irrigation is one of the few options when no the only one, to assure the maintainable agricultural production, mainly if associated to the practice of manuring. With the objective of studying the behavior of the sugarcane third leaf (Saccharum officinarium L., variety SP 791011), under different irrigation leveis and two leveis of manuring, an experiment was installed in the Capim farm of the Miriri distillery, in the municipality of Capim, Paraíba state. The experiment was accomplished through a factorial analysis of the type 2x4 (two leveis of manuring, N0 and Ni and four irrigation leveis, Wo, Wi, W2 and W3) with three replications, totaling 24 different combinations. The leveis of the manuring factor were No = 72 kg ha"1 (28 kg ha"1 of nitrogen and 44 kg ha" of potassium) and Ni = 276 kg ha"1 (112 kg ha"1 of nitrogen and 164 kg ha"1 of potassium). The manuring was applied in a single time. The leveis of the irrigation factor were WQ = 0; Wi = 152; W2 = 290 and W3 = 393 mm. The water application was made through a center pivot irrigation system, in a 12 days frequency, and the evapotranspiration calculation was based on the A class tank, subtracting the effective precipitation. The total amounts of applied water (irrigation plus effective precipitation) were Wo = 275; Wi = 927; W2 = 1.065 and W3 = 1.168 mm. Among the growth parameters studied, the number of stems, the diameter of stems and the internode number and none of the technological parameters were not influenced by the analyzed treatments. The maximum number of stems per hectare was 94.630 (given by the treatment W3 = 1.168 mm and Ni = 276 kg ha"1), which was superior to the ideal minimum limit of 90.000 stems ha"1, presented by the literature in order to obtain maximum productivities. The production of stems and the productivity of sugar and of alcohol were influenced signifícantly by the manuring and irrigation factors, but not signifícantly by the interaction manuring versus irrigation. The mean production of stems obtained in the experiment was of 82,66 t ha"1, the smallest of 68,441 ha'1 (given by the treatment Wo = 775 mm and Ni = 276 kg ha"1) and the largest of 103,091 ha"1 (given by the treatment W3 = 1.168 mm and Ni = 276 kg ha"1). The mean production of gross sugar was of 12,29 t ha"1, the smallest of 9,68 t ha"1 (given by the treatment Wo = 775 mm and No = 72 kg ha"1) and the largest of 15,29 t ha'1 (given by the treatment W3 = 1.168 mm and Ni = 276 kg ha"1). The mean production of gross alcohol was of 8,74 m ha"1, the smallest of 6,89 m3 ha"1 (given by the treatment Wo = 775 mm and No = 72 kg ha"1) and the largest of 10,88 m3 ha"1 (given by the treatment W3 =1.168 mm and NI = 276 kg ha"1). There was increment in the mean production of stems and in the productivity of sugar and of alcohol, with the increase of the irrigation levei in the treatment with larger amount of manuring.