Renewable energy sources such as biomass are becoming more and more important as alternative to fossil fuels. One of the most exciting new sources of biomass is microalgae. The Hartbeespoort Dam, located 37 km west of South Africa’s capital Pretoria, has one of the dense populations of microalgae in the world, and is one of the largest reservoirs of micro-algal biomass in South Africa. The dam has great potential for micro-algal biomass production and beneficiation due to its high nutrient loading, stable climatic conditions, size and close proximity to major urban and industrial centres. There are five major steps in the production of biodiesel from micro-algal biomass-derived oil: the first two steps involve the cultivation and harvesting of micro-algal biomass; which is followed by the extraction of oils from the micro-algal biomass; then the conversion of these oils via the chemical reaction transesterification into biodiesel; and the last step is the separation and purification of the produced biodiesel. The first two steps are the most inefficient and costly steps in the whole biomass-to-liquids (BTL) value chain. Cultivation costs may contribute between 20–40% of the total cost of micro-algal BTL production (Comprehensive Oilgae Report, 2010), while harvesting costs may contribute between 20–30% of the total cost of BTL production (Verma et al., 2010). Any process that could optimize these two steps would bring a biomass-to-liquids process closer to successful commercialization. The aim of this work was to study the cultivation and harvesting of micro-algal biomass from the Hartbeespoort Dam for the production of biodiesel. In order to do this a literature study was done and screening experiments were performed to determine the technical and economical feasibility of cultivation and harvesting methods in the context of a new integrated biomass-to-liquids biodiesel process, whose feasibility was also studied. The literature study revealed that the cyanobacterium Microcystis aeruginosa is the dominant micro-organism species in the Hartbeespoort Dam. The study also revealed factors that promote the growth of this species for possible incorporation into existing and new cultivation methods. These factors include stable climatic conditions, with high water temperatures around 25oC for optimal Microcystis growth; high nutrient loadings, with high phosphorus (e.g. PO43-) and nitrogen concentrations (e.g. NO3-); stagnant hydrodynamic conditions, with low wind velocities and enclosed bays, which promote the proliferation of Microcystis populations; and substrates like sediment, rocks and debris which provide safe protective environments for Microcystis inoculums. The seven screening studies consisted of three cultivation experiments, three harvesting experiments and one experiment to determine the combustion properties of micro-algal biomass. The three cultivation experiments were conducted in three consecutively scaled-up laboratory systems, which consisted of one, five and 135-litre bioreactors. The highest productivity achieved was over a period of six weeks in the 5-litre Erlenmeyer bioreactors with 0.0862 g/L/d at an average bioreactor day-time temperature of 26.0oC and an aeration rate of 1.5 L/min. The three cultivation experiments revealed that closed-cultivation systems would not be feasible as the highest biomass concentrations achieved under laboratory conditions were too low. Open-cultivation systems are only feasible if the infrastructure already exists, like in the case of the Hartbeespoort Dam. It is recommended that designers of new micro-algal BTL biodiesel processes first try to capitalize on existing cultivation infrastructure, like dams, by connecting their processes to them. This will reduce the capital and operating costs of a BTL process significantly. Three harvesting experiments studied the technical feasibility and determined design parameters for three promising, unconventional harvesting methods. The first experiment studied the separation of Hartbeespoort Dam micro-algal biomass from its aqueous phase, due to its natural buoyancy. Results obtained suggest that an optimum residence time of 3.5 hours in separation vessels would be sufficient to concentrate micro-algal biomass from 1.5 to 3% TSS. The second experiment studied the aerial harvesting yield of drying micro-algal biomass (3% TSS) on a patch of building sand in the sun for 24 hours. An average aerial harvesting yield of 157.6 g/m2/d of dry weight micro-algal biomass from the Hartbeespoort Dam was achieved. The third experiment studied the gravity settling harvesting yield of cultivated Hartbeespoort Dam-sourced microalgae as it settles to the bottom of the bioreactor after air agitation is suspended. Over 90% of the micro-algal biomass settled to the bottom quarter of the bioreactor after one day. Cultivated micro-algal biomass sourced from the Hartbeespoort Dam, can easily be harvested by allowing it to settle with gravity when aeration is stopped. Results showed that gravity settling equipment, with residence times of 24 hours, should be sufficient to accumulate over 90% of cultivated micro-algal biomass in the bottom quarter of a separation vessel. Using this method for primary separation could reduce the total cost of harvesting equipment dramatically, with minimal energy input. All three harvesting methods, which utilize the natural buoyancy of Hartbeespoort Dam microalgae, gravity settling, and a combination of sand filtration and solar drying, to concentrate, dewater and dry the micro-algal biomass, were found to be feasible and were incorporated into new integrated BTL biodiesel process. The harvesting processes were incorporated and designed to deliver the most micro-algal biomass feedstock, with the least amount of equipment and energy use. All the available renewable power sources from the Hartbeespoort Dam system, which included wind, hydro, solar and biomass power, were utilized and optimized to deliver minimum power loss, and increase power output. Wind power is utilized indirectly, as prevailing south-easterly winds concentrate micro-algal biomass feedstock against the dam wall of the Hartbeespoort Dam. The hydraulic head of 583 kPa of the 59.4 meter high dam wall is utilized to filter and transport biomass to the new integrated BTL facility, which is located down-stream of the dam. Solar power is used to dry the microalgae, which in turn is combusted in a furnace to release its 18,715 kW of biochemical power, which is used for heating in the power-intensive extraction unit of the processing facility. Most of the processes in literature that cover the production of biodiesel from micro-algal biomass are not thermodynamically viable, because they consume more power than what they produce. The new process sets a benchmark for other related ones with regards to its net power efficiency. The new process is thermodynamically efficient, exporting 20 times more power than it imports, with a net power output of 5,483 kilowatts. The design of a new integrated BTL process consisted of screening the most suitable methods for harvesting micro-algal biomass from the Hartbeespoort Dam and combining the obtained design parameters from these harvesting experiments with current knowledge on extraction of oils from microalgae and production of biodiesel from these oils into an overall conceptual process. Three promising, unconventional harvesting methods from Brink and Marx (2011), a micro-algal oil extraction process from Barnard (2009), and a process from Miao and Wu (2005) to produce biodiesel through the acid-catalyzed transesterification of micro-algal oil, were combined into an integrated BTL process. The new integrated biomass-to-liquids (BTL) process was developed to produce 2.6 million litres of biodiesel per year from harvested micro-algal biomass from the Hartbeespoort Dam. This is enough to supply 51,817 medium-sized automobiles per year or 142 automobiles per day of environmentally friendly fuel. The new BTL facility consists of three sections: a cultivation section where microalgae grow in the 20 km2 Hartbeespoort Dam to a concentration of 160 g/m2 during the six warmest months of the year; a harvesting section where excess water is removed from the micro-algal biomass; a reaction section where fatty acid oils are extracted from the microalgae and converted to biodiesel, and dry biomass rests are combusted to supply heat for the extraction and biodiesel units of the reaction section. The cultivation section consist of the existing Hartbeespoort Dam, which make up the cultivation unit; the harvesting section is divided into a collection unit (dam wall part of the Hartbeespoort Dam), a concentration unit, a filtration unit, and a drying unit; the reaction section consists of an oil extraction unit, a combustion unit, and a biodiesel unit. At a capital cost of R71.62 million (R1.11/L) (±30%), the new proposed BTL facility will turn 933,525 tons of raw biomass (1.5% TSS) into 2,590,856 litres of high quality biodiesel per year, at an annual operating cost of R11.09 million (R4.28/L at 0% producer inflation), to generate R25.91 million (R10.00/L) per year of revenue. At the current diesel price of R10.00/L, the new integrated BTL process is economically feasible with net present values (NPV) of R368 million (R5.68/L) and R29.30 million (R0.45/L) at discount rates of 0% and 10%, respectively. The break-even biodiesel prices are R5.34/L and R7.92/L, for a zero NPV at 0% and 10% discount rates, respectively. The cultivation of micro-algal biomass from the Hartbeespoort Dam is only economical if the growth is allowed to occur naturally in the dam without any additional cultivation equipment. The cultivation of micro-algal biomass in either an open or a closed-cultivation system will not be feasible as the high cost of cultivation will negate the value of biodiesel derived from the cultivated biomass. The utilization of the three promising harvesting methods described in this work is one of the main drivers for making this process economically feasible. At a capital cost of R13.49 million (R37.77/ton of dry weight micro-algal biomass) and a operating cost of R2.00 million per year (R210.63/ton of dry weight micro-algal biomass) for harvesting micro-algal biomass from the Hartbeespoort Dam, harvesting costs account for only 19% and 18% of the overall capital and operating costs of the new process, respectively. This is less than harvesting costs for other comparative processes world-wide, which contribute between 20 and 30% of the overall cost of biomass-to-liquids production. At current fuel prices, the cultivation of micro-algal biomass from and next to the Hartbeespoort Dam is not economical, but the unconventional harvesting methods presented in this thesis are feasible, if incorporated into the new integrated biomass-to-liquids biodiesel process set out in this work. / Thesis (Ph.D. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2011.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1979. / Bibliography: leaves 176-185. / Microfiche. / xi, 185 leaves ill. 29 cm

Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (M.Phil.)--University of Queensland, 2003. / Includes bibliography.

Orientador: Miguel Angelo Mutton / Banca: Antonio César Bolonhezi / Banca: Marcos Guimarães de Andrade Landell / Resumo: Objetivando avaliar os efeitos da queima da palhada e conseqüentemente da soqueira brotada, nos rendimentos agroindustriais da safra seguinte e estudar a melhor opção de tratos culturais, realizou-se um experimento na Companhia Energética Santa Elisa (Sertãozinho - SP) na safra 2001/02. Utilizou-se a variedade RB855536, em estágio de 4 º corte, plantada em Latossolo Vermelho Distroférrico. O delineamento utilizado foi em parcelas sub-subdivididas com cinco repetições, com dois tratamentos principais (palhada queimada e não queimada); dois secundários (com e sem cultivo da soqueira) e dois terciários (doses de nitrogênio: 0 e 32 kg.ha-1). A queima acidental da palhada não afetou a produtividade de colmos e a qualidade da matéria prima (Pol % Cana) da safra seguinte, para colheita após 10,6 meses. Até 8,7 meses após a queima acidental da palhada, a área não deve ser colhida em função do menor teor de sacarose nos colmos (Pol % Cana). No tratamento palhada queimada houve maior perfilhamento no ciclo e maior número de colmos por metro na colheita, embora com menor peso unitário. A aplicação suplementar de nitrogênio incrementou a produtividade de colmos e de Pol, na ausência (queima) como na presença da palhada. O cultivo da soqueira não teve efeito sobre a produtividade de colmos e qualidade da matéria prima (Pol % Cana). / Abstract: Aiming to evaluate the effects of burning sugar-cane straw before harvest, which consequently burns the sprouting ratoon also, on agricultural and industrial yields of the next harvest and study the best crop management option, we carried out a field experiment at the Companhia Energética Santa Elisa in Sertáozinho (São Paulo, State) during harvest of the years 2001/2002. The soil was an oxisoil, and the sugarcane variety was RB855536, in its 4th cutting stage. The experiment design was a split-split-plot with five repetitions. The main treatments consisted of burning and not burning the straw. Secondary treatments were: ratoon cultivation (yes or not), and tertiary were the application of two different doses of nitrogen (0 and 32 kg.ha-1). The burning of the straw did not affect the productivity of culms and percentage of sucrose of the cane (Pol% cane) in the following year, harvesting after 10.6 months. Up to 8.7 months after the accidental burn of the straw the harvest is not recommended in function of the smaller sucrose percentage in the culms. The burning of the straw increased the number of culms of lower weight. Nitrogen application determined an increment on the productivity of culms and Pol, in the absence (burn) as in presence of the straw. Ratoon cultivation did not affect productivity of culms and percentage of sucrose of the cane (Pol% cane). / Mestre

Produzir trigo de duplo propósito possibilita ao agricultor dar ênfase às alternativas mais rentáveis em função da variação dos preços pagos pelos produtos, entretanto, a época de diferimento e os efeitos do pastejo sobre a produção ainda precisam ser elucidados. Diante disso, o objetivo do presente trabalho, conduzido na área do Instituto Agronômico do Paraná (IAPAR) na estação experimental de Pato Branco- PR, foi avaliar a influência de diferentes períodos de pastejo (0, 21, 42, 63, 84 e 105 dias) sobre a produção de grãos de trigo da cultivar BRS Tarumã e a produção animal de bovinos da raça Purunã com peso médio de 162 kg e idade de 10 meses, que permaneceram sob pastejo com lotação contínua e taxa de lotação variável. Durante o período experimental (abril a novembro de 2007), avaliou-se: massa, oferta e qualidade da forragem, carga animal, taxa de lotação, ganho de peso vivo por área e ganho médio diário e produção de grãos em delineamento experimental de blocos ao acaso com seis tratamentos e duas repetições. O pastejo pode ser executado com resultados eficientes para produção animal até os 88 dias, porém ocorre redução na produção de grãos de acordo com o aumento do período de pastejo. / The double purpose wheat production (animal and grain production) allows some flexibility in the crop livestock production system and permit to the farmers to choose the best alternative according to the prices paid to the products, although, the deferment periods and the grazing effects over the wheat production need to be studied. The aim of the present work, carried out at the Agronomist institute of Paraná (IAPAR), experimental unit of Pato Branco-PR, was to evaluate the effect of six grazing periods (0, 21, 42, 63, 84 and 105 days) over the wheat grain production, BRS Tarumã cultivar and the animal production of Purunã steers with average live weight of 162 kg and age of 10 months managed on continuous stocking rate. During the experimental period (April to November of 2007) were evaluated: forage mass, offer and nutritive value, intake, stocking rate, animal daily gain and gain per hectare and wheat grain production. The experiment was laid out as randomized complete (RCBD) block design with six treatments and two eplications. The grazing period can be kept until 88 days with efficient results to the animal production, however, the grains production decreased with grazing use.

The thesis deals with renewable resources, biomass a its possible uses. The work is focused on Miscanthus sinensis. It described characteristics of plants, growing technology, harvesting and possible ways to use it - mainly burning. Attention is also focused on the yield potential of plants. The practical part of the thesis describes experiments with miscanthus at the experimental site in České Budějovice. There are reported experimental results and their evaluation and comparison with the literature.

LOPES, Camila Pessoa. O espírito livre em Nietzsche. 2007. 139f. – Dissertação (Mestrado) – Universidade Federal do Ceará, Programa de Pós-graduação em Filosofia, Fortaleza (CE), 2007. / Submitted by Gustavo Daher (gdaherufc@hotmail.com) on 2017-09-27T12:47:36Z No. of bitstreams: 1 2007_dis_cplopes.pdf: 964244 bytes, checksum: c79a2baa30cf663c2aad912645d8347c (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2017-09-29T13:49:38Z (GMT) No. of bitstreams: 1 2007_dis_cplopes.pdf: 964244 bytes, checksum: c79a2baa30cf663c2aad912645d8347c (MD5) / Made available in DSpace on 2017-09-29T13:49:38Z (GMT). No. of bitstreams: 1 2007_dis_cplopes.pdf: 964244 bytes, checksum: c79a2baa30cf663c2aad912645d8347c (MD5) Previous issue date: 2007 / The objective of the present work is to explore Nietzsche’s concept of free spirit. To comprehend that concept we will first atempt to understand the distinction Nietzsche establishes between romantic pessimism end dionisiac pessimism and, therefor, Nietzsche’s description of the two types of pessimists in humanity, those suffering an impoverishment of life and those suffering an abundance of life. Breaking from the philosophy of Schopenhauer, Nietzsche invents the free spirits to whom he dedicates his philosophy. Nietzsche calls them the philosophers of the future, those who will have the inclination to comprehend what is perspectivism in each evaluation, as well as to apprehend the necessary injustice of all pros and cons. They must take into account the problem of hierarchy, in others words, that which throughout history we learned to feel as worth. Self cultivation, therefor, implicates the flowering of the free spirit. To achieve this, cultural conditions are mixed with aspects of instinctive life singularities that result in the modeling, the formation of the spirit. “Free spirit’s natural history” is a laconic fragment that gives us the opportunity to issue a commentary about the morality of customs and the history of moral feelings. Convinced of this invention, it is apprehend that Nietzsche’s philosophy constantly imposes the contrast between the individual and the politic, thus revealing the necessity to affirm it vehemently as an alternative to any situation that does not consider the possibilities of individual growth, or that weakens individual nature, both situations verified and proved with the nihilism of modern ideas. With the free spirit one hopes to take a step forward into the knowledge and the overcoming of moral. / O presente trabalho tem por objetivo explorar o que Nietzsche conceitua como espírito livre. Para a compreensão desse conceito, em primeiro lugar procuraremos compreender a distinção feita por ele entre pessimismo romântico e pessimismo dionisíaco e, por conseguinte, sua descrição sobre os dois tipos de pessimistas na humanidade, aqueles que sofrem de empobrecimento e aqueles que sofrem de abundância de vida. Rompendo com a filosofia de Schopenhauer, Nietzsche inventa os espíritos livres e a eles dedica sua filosofia. Ele os chama de filósofos do futuro, aqueles que terão o pendor para compreender o que é perspectivista em cada valoração, como também, para apreender a injustiça necessária de todo pró e contra. Eles devem olhar o problema da hierarquia, ou seja, aquilo que durante a história aprendemos a sentir como valor. O cultivo de si, portanto, implica o florescimento do espírito livre. Para tanto as condições da cultura são mescladas a aspectos da singularidade da vida instintiva que acabam por modelar, por formar o espírito. “A história natural do espírito livre” é um lacônico fragmento que enseja o comentário sobre a moralidade dos costumes e a história dos sentimentos morais. Certos dessa invenção, apreende-se que a filosofia de Nietzsche põe constantemente o contraste entre o individual e o político, revelando-se assim a necessidade de afirmá-la de forma contundente, como uma alternativa à qualquer situação que desconsidera as possibilidades de crescimento individual ou que enfraqueça a natureza do indivíduo, ambas situações constatadas e constatáveis com o niilismo das idéias modernas. Com o espírito livre espera-se um passo avante no conhecimento e a superação da moral.

Resumo: Devido a mudanças no hábito alimentar o consumo de alface vem aumentando, sendo seu fornecimento diário, o ano todo. Sendo assim, o cultivo hidropônico tem sido adotado por muitos produtores. Apesar disso, muitas cultivares ainda não são adaptadas a essa tecnologia. O objetivo deste trabalho foi avaliar o desempenho de cinco cultivares de alface em dois ambientes de cultivo no sistema hidropônico, tipo NFT, no período de 06/02 a 07/04 de 2006 em Ribeirão Preto, estado de São Paulo, Brasil. Para isso as cultivares Pira Roxa, Pira Vermelha, Locarno, Crespona gigante e Verônica foram avaliadas em casa de vegetação convencional e climatizada em sistema NFT (Técnica do fluxo laminar de nutrientes). O delineamento experimental foi em blocos casualizados, sendo cinco cultivares em três blocos. A colheita foi realizada aos 61 dias da semeadura sendo avaliadas a massa fresca e seca da parte aérea, caule e raízes; número de folhas maiores que 10 cm e número total de folhas. A cultivar Crespona gigante não diferiu da cv. Verônica em massas fresca e seca da parte aérea, mas foi superior às cultivares Pira Vermelha, Pira Roxa e Locarno. As cultivares Pira Roxa e Pira Vermelha sugeriram melhor adaptação, indicando maior resistência ao pendoamento. Não houve efeito significativo para a interação, cultivares e ambientes, mostrando que as cultivares comportaram-se de forma semelhante nos dois ambientes. Houve um maior consumo de água pelas plantas de alface na casa de vegetação convencional em relação à climatizada, provavelmente devido às maiores temperaturas e à menor umidade relativa do ar. A extração de nutrientes pelas folhas de alface (média de cinco cultivares) obedeceu a seguinte ordem decrescente: K>N>Ca>Mg>P>S>Fe>Mn>Zn>Cu. / Abstract: Due to changes in feeding habits, lettuce consumption has been increasing and must be supplied daily throughout the year. As a result, many producers have adopted hydroponics’ cultivation. In spite of this, many cultivars are not yet adapted to this technology. The objective of this study was to evaluate the performance of five lettuce cultivars grown in two environmentals in NFT (Nutrient Film Technique) hydroponic system in the period from Feb/06 to Apr/07 2006 in Ribeirão Preto, state of São Paulo, Brazil. To accomplish this, cultivars Pira Roxa, Pira Vermelha, Locarno, Crespona gigante, and Verônica were evaluated in conventional and climatizated greenhouse in the NFT system. A randomized-block experimental design was used, consisting of five cultivars in three blocks. Harvest was performed 61 days after seeding. Evaluations were made for fresh and dry mass of the aerial part, stem, and roots; number of leaves larger than 10 cm; and total number of leaves. Cultivar Crespona gigante in fresh weight and dry matter of the aerial part did not differ from cultivar Verônica, but it was superior to them cultivars Pira Roxa, Pira Vermelha and Locarno.The cultivars Pira Roxa and Pira Vermelha suggested a better adaptation, showing better resistance to bolting. There was no significant effect of the cultivars OE environments interaction, demonstrating that the cultivars had similar behaviors in both environments. There was a larger consumption of water by the lettuce plants under the conventional greenhouse conditions in comparison to the acclimated one, probably due to their higher temperatures and lower air relative humidities. The extraction of nutrients by leaves lettuce plants (average five to cultivate) obeyed to the followed the decreasing order: K>N>Ca>Mg>P>S>Fe>Mn>Zn>Cu. / Orientador: Jairo Augusto Campos de Araújo / Coorientadora: Sally Ferreira Blat / Banca: Glauco Eduardo Pereira Cortez / Banca: Luiz Vitor Egas Villela Junior / Mestre

Made available in DSpace on 2014-06-11T19:28:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-01-25Bitstream added on 2014-06-13T18:57:48Z : No. of bitstreams: 1 sanchez_sv_me_jabo.pdf: 656340 bytes, checksum: 8e649f75039e1236f6fe05b62ced4d09 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Devido a mudanças no hábito alimentar o consumo de alface vem aumentando, sendo seu fornecimento diário, o ano todo. Sendo assim, o cultivo hidropônico tem sido adotado por muitos produtores. Apesar disso, muitas cultivares ainda não são adaptadas a essa tecnologia. O objetivo deste trabalho foi avaliar o desempenho de cinco cultivares de alface em dois ambientes de cultivo no sistema hidropônico, tipo NFT, no período de 06/02 a 07/04 de 2006 em Ribeirão Preto, estado de São Paulo, Brasil. Para isso as cultivares Pira Roxa, Pira Vermelha, Locarno, Crespona gigante e Verônica foram avaliadas em casa de vegetação convencional e climatizada em sistema NFT (Técnica do fluxo laminar de nutrientes). O delineamento experimental foi em blocos casualizados, sendo cinco cultivares em três blocos. A colheita foi realizada aos 61 dias da semeadura sendo avaliadas a massa fresca e seca da parte aérea, caule e raízes; número de folhas maiores que 10 cm e número total de folhas. A cultivar Crespona gigante não diferiu da cv. Verônica em massas fresca e seca da parte aérea, mas foi superior às cultivares Pira Vermelha, Pira Roxa e Locarno. As cultivares Pira Roxa e Pira Vermelha sugeriram melhor adaptação, indicando maior resistência ao pendoamento. Não houve efeito significativo para a interação, cultivares e ambientes, mostrando que as cultivares comportaram-se de forma semelhante nos dois ambientes. Houve um maior consumo de água pelas plantas de alface na casa de vegetação convencional em relação à climatizada, provavelmente devido às maiores temperaturas e à menor umidade relativa do ar. A extração de nutrientes pelas folhas de alface (média de cinco cultivares) obedeceu a seguinte ordem decrescente: K>N>Ca>Mg>P>S>Fe>Mn>Zn>Cu. / Due to changes in feeding habits, lettuce consumption has been increasing and must be supplied daily throughout the year. As a result, many producers have adopted hydroponics cultivation. In spite of this, many cultivars are not yet adapted to this technology. The objective of this study was to evaluate the performance of five lettuce cultivars grown in two environmentals in NFT (Nutrient Film Technique) hydroponic system in the period from Feb/06 to Apr/07 2006 in Ribeirão Preto, state of São Paulo, Brazil. To accomplish this, cultivars Pira Roxa, Pira Vermelha, Locarno, Crespona gigante, and Verônica were evaluated in conventional and climatizated greenhouse in the NFT system. A randomized-block experimental design was used, consisting of five cultivars in three blocks. Harvest was performed 61 days after seeding. Evaluations were made for fresh and dry mass of the aerial part, stem, and roots; number of leaves larger than 10 cm; and total number of leaves. Cultivar Crespona gigante in fresh weight and dry matter of the aerial part did not differ from cultivar Verônica, but it was superior to them cultivars Pira Roxa, Pira Vermelha and Locarno.The cultivars Pira Roxa and Pira Vermelha suggested a better adaptation, showing better resistance to bolting. There was no significant effect of the cultivars OE environments interaction, demonstrating that the cultivars had similar behaviors in both environments. There was a larger consumption of water by the lettuce plants under the conventional greenhouse conditions in comparison to the acclimated one, probably due to their higher temperatures and lower air relative humidities. The extraction of nutrients by leaves lettuce plants (average five to cultivate) obeyed to the followed the decreasing order: K>N>Ca>Mg>P>S>Fe>Mn>Zn>Cu.