Within the home environment there exits a host of digital color imaging (DCI) system configurations. The combination of devices and software at the consumer's desktop with devices and services at a remote location (e.g., Print at Kodak), creates a complex interaction of device, contextual, and observer characteristics. In particular, the cathode-ray tube (CRT) display has the potential to influence consumers' perceptions of image quality and their subsequent image manipulation activities. Depending on the inherent color bias and apparent contrast of the CRT, extensive image manipulation may occur, significantly altering the digital values of the image. Output generated by a remote printer will reflect any image manipulation undertaken by the consumer. If manipulation was extensive, what the consumer receives from a remote printer will appear quite different from the softcopy version and thus, may be deemed unacceptable. This research was designed to address the softcopy-hardcopy matching issues that arise from the home DCI system configuration just described. The primary study examined how the CRT display influenced perceived color quality of photographs generated at two points in a DCI system; on-screen photographs (softcopy) and photographic quality prints (hardcopy). CRT gamma, color temperature, and excitation purity were manipulated using an orthogonal, blocked, central composite design. Twenty-two Eastman Kodak Company employees viewed 6 photographs under each of the 15 CRT conditions. Participants rated the color quality of each softcopy photograph, then were given an opportunity to edit color balance, brightness, and contrast for each photograph. The edited photos were printed and rated once again for color quality and acceptability. Results indicated that monitor calibration influenced perceived softcopy color quality, softcopy editing behavior, and subsequent perceived hardcopy color quality. Perception of softcopy color quality ratings was determined predominantly by the CRT gamma level. Participants responded to CRT color balance differences through their editing behavior. In some cases, edits were large enough to significantly and negatively impact perceived hardcopy color quality. Gamma in particular, was the most significant predictor of hardcopy color quality ratings and rejection rates. Additional differences were observed between first- and third-party photographs. Results from this research may be applied to the development of monitor calibration tools, scene balancing algorithms, and software, for the purpose of accommodating consumer image manipulation behavior, in the context of the home DCI system presented herein. / Ph. D.

This thesis deals with the possibility of applying the method of Design of Experiments (DoE) on specific data. In the first chapter of theoretical part, this method is described in detail. The basic principles and guidelines for the design of the experiment are written there. In the next two chapters, factorial design of the experiment and response surface design are described. The latter one includes a central composite design and Box-Behnken design. The following chapter contains practical part, which focuses on modelling firing range of ball from a catapult using the above three types of experimental design. In this work, the models are analysed together with their different characteristics. Their comparison is made by using prediction and confidence intervals and by response optimizing. The last part of the thesis comprises overall evaluation.

The effects of vapor-grown carbon nanofiber (VGCNF) weight fraction, applied stress, and temperature on the viscoelastic responses (creep strain, creep rate, and creep compliance) of VGCNF/vinyl ester (VE) nanocomposites were studied using a central composite design (CCD). The nanocomposite test articles were fabricated by high shear mixing, casting, curing, and post-curing in an open face mold under a nitrogen environment. Short-term creep/creep recovery experiments were conducted at prescribed combinations of temperatures (23.8 – 69.2 C), applied stresses (30.2 – 49.8 MPa), and VGCNF weight fractions (0.00 – 1.00 parts of VGCNF per hundred parts of resin, phr) determined from the CCD. The response surface models (RSMs) for predicting these viscoelastic responses were developed using the least squares method and an analysis of variance procedure. The response surface estimates indicate that increasing the VGCNF weight fraction decreases the creep resistance of the VGCNF/VE nanocomposites at high temperatures (46.5 – 69.2 C).

No description available.

Existe um número muito limitado de estudos referentes à produção de componentes antimicrobianos ou bacteriocinas produzidas por espécies de bifidobactérias. Nesse âmbito, o objetivo deste trabalho foi avaliar a produção de bifidobacteriocina em leite desnatado (LD). Para tanto, o estudo foi dividido em três etapas. A primeira etapa constituiu na preparação dos meios de cultura Man, Rogosa e Sharpe (MRS), Bifidus Selective Medium (BSM) e LD suplementado com 1% (p/v) de Tween 80 (T80), Inulina (I) ou Extrato de levedura (YE). Nesta etapa, os processos fermentativos foram conduzidos em shaker, nas condições: 50 rpm/37ºC/48h. Foram realizadas análises de pH, concentração de açúcares e ácidos, crescimento celular e determinação da atividade da bifidobacteriocina pelo método de difusão em ágar contra L. monocytogenes. Na segunda etapa, e baseado nos resultados obtidos, foi desenhado um delineamento composto central (CCD) construído a partir dos seguintes parâmetros: temperatura (34, 37, 40 °C) e concentração de YE (0,5; 1,0; 1,5 g/L). Na terceira etapa do trabalho, foram realizados os cultivos em biorreator de 2 L, contendo 10% de leite desnatado, nas seguintes condições: 200 rpm, 36°C, 2,0 g/L de YE, 48h de incubação em anaerobiose. Obteve-se em LD suplementado com YE (1%), combinado ao método de difusão em placa modificado (prévia refrigeração das placas por 12h), contra L. monocytogenes (2130 AU/mL), com uma fase exponencial de 24h, µm de 0,604/h. A otimização feita através do CCD permitiu atingir níveis de atividade de 3.000 AU/mL a 3.100 AU/mL (ensaios 7, 11 e 14, blocos 3 e 1) contra L. monocytogenes, em condições ótimas de crescimento de YE: 2,0 g/L1 e T°C: 36°C. A análise de regressão mostrou ser estatisticamente significativa a relação entre as variáveis: \"concentração de \"YE e temperatura\". Os resultados indicaram que o leite desnatado é um meio adequado para produção de bifidobacteriocina. / There are few publications that have been reported about bacteriocin production by Bifidobacterium species. Therefore, the aim of this work was measure bacteriocin production in skim milk by B. lactis. Consequently, this work was divided in three stages. First, MRS, BSM and LD medium were tested with additives (Tween 80 (T80), Inuline (I) or Yeast extract (YE)) for bacteriocin production and cellular growth. Fermentation processes were conducted in shaker under specific conditions: 50 rpm/37ºC/48h. pH; sugars; acids; biomass, and bacteriocin activity against L. monocytogenes, L. plantarum, E. coli, L. sakei e S. aureus strains were analyzed . In the second stage, based on the obtained results, a central composite design (CCD) was created using the parameters: temperature (34, 37, 40 ºC), and concentration of YE (0.5, 1.0, 1.5 g/L). After, the activity was measured by two methods of plates pre-diffusion (cooling and addition of Tween 20). Third step consisted of 2 L bioreactor cultivations containing 10% skim milk diluted in 1.5 L of water (6.5 pH), under 200 rpm, 36 ºC, 2.0 g/L of YE, 48h, under anaerobic condition. Finally, the cultures supplemented with LD and YE (1%) with a modified plate diffusion method (cooling plates for 12 h) showed bacteriocin activity against L. monocytogenes (2130 AU/mL) with an exponential phase of 24 h, µm of 0.604/h. The optimization performed using CCD resulted in a higher level of activity 3000 AU/mL to 3100 AU/mL mL (Run 7, 11 and 14, blocks 3 and 1) against L. monocytogenes, also with ideal growth conditions of YE: 2,0 g/L1 and T °C: 36 °C. The pH value varied between 6.4 and 4.0. Concentration of produced acid lactic varied from 3.03 to 4.72 g/L and biomass concentration from 3.4 to 11.1 Lg UFC/mL. Regression analysis was significant to the variables: YE concentration and temperature. Results indicated that skim milk is a proper medium for \"Bifidobacteriocin\" production.

Made available in DSpace on 2017-07-21T18:53:04Z (GMT). No. of bitstreams: 1 CRISTIANE BOURSCHEID.pdf: 1448163 bytes, checksum: 21f79c9c1335f39830bfef99ee3f5f19 (MD5) Previous issue date: 2015-03-11 / The chicken slaughterhouse generate co-products during slaughter, for example, feathers, bones, blood and guts, usually intended for animal feed with low added value. In bone part of the meat remains bound even after deboning and is a good source of substrate for the enzymatic hydrolysis. The protein hydrolysates may be applied as a nutritional supplement in foods. Given this context, the objective was to optimize the enzymatic hydrolysis process for obtaining protein hydrolyzate coproduct of chicken bones (Gallus gallus domesticus) and the addition of the hydrolyzate as a protein supplement in burger. The co-product selected to carry out the work was thigh and drumstick bone from the chicken bones in a slaughterhouse. The study was conducted in two stages. In the first one a central composite design (CCRD), a total of 17 tests was adopted to evaluate the influence of temperature, enzyme: substrate ratio and time on the degree of hydrolysis. Following the statistical optimization was performed to obtain the best conditions of enzymatic hydrolysis of co-product of chicken bones. The co-product of chicken bones and the optimized protein hydrolyzate were characterized in terms of chemical composition, total amino acids and pattern. In the second step, the hydrolyzate was added as a protein supplement in poultry burger, where two formulations were prepared, Hamburger control (no addition of protein hydrolyzate) and hamburger with hydrolyzed (with addition of 8% protein hydrolyzate). The burgers were characterized in terms of physical-chemical, microbiological and sensory analysis. The optimum conditions for the enzymatic hydrolysis were temperature (T) of 50 ° C, enzyme: substrate ratio (E:S) from 4.96% to time (t) of 110.16 minutes under these conditions the degree of hydrolysis was 24, 0.22 ± 21%. The protein hydrolyzate has the potential to supplementation in food, it is good source of essential amino acids, meeting the recommendations established by FAO / WHO, except for leucine, phenylalanine, and valine, and had a higher concentration of protein fractions from 14.437 kDa and 3,496 kDa. The results obtained for microbiological analysis and physical-chemical analysis of the burger control and burger with hydrolyzed, are in accordance with the respective standards set by law. The burger with hydrolyzate showed 1.02% more protein than the burger control, giving a protein supplementation to the product developed. In the sensorial analysis for flavor attribute evaluators preferred the burger with protein hydrolyzate. The burger with protein hydrolyzate and the burger control achieved 84.2% and 81.8% of general acceptance, respectively. The intention to buy for the burger with added protein hydrolyzate was 76.4% and for the burger control was 67%. In this light, the protein hydrolyzate obtained from chicken bones of the co-product is an alternative to supplementation in foods, as well as add value to the co-product of chicken dessosa and increase the competitiveness of slaughterhouse. / Os frigoríficos de frango geram coprodutos durante o abate, por exemplo, penas, ossos, sangue e vísceras, geralmente, destinados para ração animal com baixo valor agregado. Uma parte de carne permanece aderida aos ossos, mesmo após a desossa, sendo uma boa fonte de substrato para a hidrólise enzimática. Os hidrolisados proteicos podem ser aplicados como suplemento nutricional em alimentos. Diante desse contexto, o objetivo do trabalho foi otimizar o processo de hidrólise enzimática para obtenção de hidrolisado proteico de coproduto da desossa de frango (Gallus gallus domesticus) e a adição do hidrolisado como suplemento proteico em hambúrguer. O coproduto selecionado para realização do trabalho foi osso de coxa e sobrecoxa proveniente da desossa de frango em frigorífico. O trabalho foi realizado em duas etapas. Na primeira um delineamento composto central rotacional (DCCR), totalizando 17 ensaios foi adotado para avaliar a influência da temperatura, relação enzima:substrato e tempo sobre o grau de hidrólise. Na sequência, foi realizada a otimização estatística para obter as melhores condições da hidrólise enzimática. O coproduto da desossa de frango e o hidrolisado proteico otimizado foram caracterizados em termos de composição centesimal, aminoácidos totais e perfil eletroforético. Na segunda etapa, o hidrolisado foi adicionado como suplemento proteico em hambúrguer de frango. Foram elaboradas duas formulações, hambúrguer controle (sem adição de hidrolisado proteico) e hambúrguer com hidrolisado (com adição de 8% de hidrolisado proteico). Os hambúrgueres foram caracterizados em termos de análises físico-químicas, análises microbiológicas e análise sensorial. As condições ótimas para a hidrólise enzimática foram temperatura (T) de 50ºC, relação enzima:substrato (E:S) de 4,96% e tempo (t) de 110,16 minutos, nessas condições o grau de hidrólise foi de 24,21% ±0,22. O hidrolisado proteico apresentou potencial para suplementação em alimentos, pois é boa fonte de aminoácidos essenciais, atendendo as recomendações estabelecidas pela FAO/WHO, exceto para leucina, fenilalanina e valina, bem como apresentou maior concentração de frações proteicas entre 14,437 kDa e 3,496 kDa. Os resultados obtidos para a análise microbiológica e análises físico-químicas do hambúrguer controle e do hambúrguer com hidrolisado, estão de acordo com os respectivos padrões estabelecidos pela legislação vigente. O hambúrguer com hidrolisado apresentou 6% mais proteína do que o hambúrguer controle, conferindo uma suplementação proteica ao produto desenvolvido. Em relação à análise sensorial para o atributo sabor, os avaliadores preferiram o hambúrguer com hidrolisado proteico. O hambúrguer com hidrolisado proteico e o hambúrguer controle obtiveram 84,2% e 81,8% de aceitação geral, respectivamente. A intenção de compra para o hambúrguer com adição de hidrolisado proteico foi de 76,4% e para o hambúrguer controle foi de 67%. Diante do exposto, o hidrolisado proteico obtido a partir de coproduto da desossa de frango é uma alternativa para a suplementação em alimentos, além de agregar valor ao coproduto da dessosa de frango e aumentar a competitividade dos frigoríficos.

Existe um número muito limitado de estudos referentes à produção de componentes antimicrobianos ou bacteriocinas produzidas por espécies de bifidobactérias. Nesse âmbito, o objetivo deste trabalho foi avaliar a produção de bifidobacteriocina em leite desnatado (LD). Para tanto, o estudo foi dividido em três etapas. A primeira etapa constituiu na preparação dos meios de cultura Man, Rogosa e Sharpe (MRS), Bifidus Selective Medium (BSM) e LD suplementado com 1% (p/v) de Tween 80 (T80), Inulina (I) ou Extrato de levedura (YE). Nesta etapa, os processos fermentativos foram conduzidos em shaker, nas condições: 50 rpm/37ºC/48h. Foram realizadas análises de pH, concentração de açúcares e ácidos, crescimento celular e determinação da atividade da bifidobacteriocina pelo método de difusão em ágar contra L. monocytogenes. Na segunda etapa, e baseado nos resultados obtidos, foi desenhado um delineamento composto central (CCD) construído a partir dos seguintes parâmetros: temperatura (34, 37, 40 °C) e concentração de YE (0,5; 1,0; 1,5 g/L). Na terceira etapa do trabalho, foram realizados os cultivos em biorreator de 2 L, contendo 10% de leite desnatado, nas seguintes condições: 200 rpm, 36°C, 2,0 g/L de YE, 48h de incubação em anaerobiose. Obteve-se em LD suplementado com YE (1%), combinado ao método de difusão em placa modificado (prévia refrigeração das placas por 12h), contra L. monocytogenes (2130 AU/mL), com uma fase exponencial de 24h, µm de 0,604/h. A otimização feita através do CCD permitiu atingir níveis de atividade de 3.000 AU/mL a 3.100 AU/mL (ensaios 7, 11 e 14, blocos 3 e 1) contra L. monocytogenes, em condições ótimas de crescimento de YE: 2,0 g/L1 e T°C: 36°C. A análise de regressão mostrou ser estatisticamente significativa a relação entre as variáveis: \"concentração de \"YE e temperatura\". Os resultados indicaram que o leite desnatado é um meio adequado para produção de bifidobacteriocina. / There are few publications that have been reported about bacteriocin production by Bifidobacterium species. Therefore, the aim of this work was measure bacteriocin production in skim milk by B. lactis. Consequently, this work was divided in three stages. First, MRS, BSM and LD medium were tested with additives (Tween 80 (T80), Inuline (I) or Yeast extract (YE)) for bacteriocin production and cellular growth. Fermentation processes were conducted in shaker under specific conditions: 50 rpm/37ºC/48h. pH; sugars; acids; biomass, and bacteriocin activity against L. monocytogenes, L. plantarum, E. coli, L. sakei e S. aureus strains were analyzed . In the second stage, based on the obtained results, a central composite design (CCD) was created using the parameters: temperature (34, 37, 40 ºC), and concentration of YE (0.5, 1.0, 1.5 g/L). After, the activity was measured by two methods of plates pre-diffusion (cooling and addition of Tween 20). Third step consisted of 2 L bioreactor cultivations containing 10% skim milk diluted in 1.5 L of water (6.5 pH), under 200 rpm, 36 ºC, 2.0 g/L of YE, 48h, under anaerobic condition. Finally, the cultures supplemented with LD and YE (1%) with a modified plate diffusion method (cooling plates for 12 h) showed bacteriocin activity against L. monocytogenes (2130 AU/mL) with an exponential phase of 24 h, µm of 0.604/h. The optimization performed using CCD resulted in a higher level of activity 3000 AU/mL to 3100 AU/mL mL (Run 7, 11 and 14, blocks 3 and 1) against L. monocytogenes, also with ideal growth conditions of YE: 2,0 g/L1 and T °C: 36 °C. The pH value varied between 6.4 and 4.0. Concentration of produced acid lactic varied from 3.03 to 4.72 g/L and biomass concentration from 3.4 to 11.1 Lg UFC/mL. Regression analysis was significant to the variables: YE concentration and temperature. Results indicated that skim milk is a proper medium for \"Bifidobacteriocin\" production.

Experiments with both quantitative and qualitative factors always complicate the selections of experimental settings and the statistical analysis for data. Response surface methodology (RSM) provides the systematic procedures such as the steepest ascent method to develop and improve the response models through the optimal settings of quantitative factors. However the sequential method lacks of exploring the direction of the maximum increase in the response among the qualitative levels. In this dissertation the optimal designs for experiments with both qualitative and quantitative factors are investigated. Focused on the second-order response surface model for quantitative factors, which is widely used in RSM as a good approximation for the true response surface, the approximate and exact D-optimal designs are proposed for the model containing the qualitative effects. On spherical design regions, the D-optimal designs have particular structures for considering the qualitative effects to be fixed or random. In this study, the exact D-optimal designs for a second-order response surface model on a circular design region with qualitative factors are proposed. For this model, the interactions between the quantitative and qualitative factors are assumed to be negligible. Based on this design region, an exact D-optimal design with regular polygon structure is made up according to the remainder terms of the numbers of experimental trials at each qualitative levels divided by 6. The complete proofs of exact D-optimality for models including two quantitative factors and one 2-level qualitative factor are presented as well as those for a model with only quantitative factors. When the qualitative factor has more than 2 levels, a method is proposed for constructing exact designs based on the polygonal structure with high efficiency. Furthermore, a procedure for minimizing the number of support points for the quantitative factors of exact D-optimal designs is also proposed for practical consideration. There are no more than 13 support points for the quantitative factors at an individual qualitative level. When the effects between the quantitative and qualitative factors are taken into consideration, approximate D-optimal designs are investigated for models in which the qualitative effects interact with, respectively, the linear quantitative effects, or the linear effects and 2-factor interactions of the quantitative factors or quadratic effects of the quantitative factors. It is shown that, at each qualitative level, the corresponding D-optimal design consists of three portions as a central composite design but with different weights on the cube portion, star portion and center points. Central composite design (CCD) is widely applied in many fields to construct a second-order response surface model with quantitative factors to help to increase the precision of the estimated model. A chemical study is illustrated to show that the effects of the qualitative factor interacts with 2-factor interactions of the quantitative factors are important but absent in a second-order model including a qualitative factor treated as a coded variable. The verification of the D-optimality for exact designs has become more and more intricate when the qualitative levels or the number of quantitative factors increase, even when the patterns of the exact optimal designs have been speculated. The efficient rounding method proposed by Pukelsheim and Rieder (1992) is a model-free approach and it generates an exact design by apportioning the number of trials on the same support points of a given design. For constructing the exact designs with high efficiencies, a modified efficient rounding method is proposed and is based on the polygonal structure of the approximate D-optimal design on a circular design region. This modification is still based on the same rounding approach by apportioning the number of trials to the concentric circles where the support points of the given design are standing on. Then a regular polygon design will be assigned on the circles by the apportionments. For illustration, the exact designs for a third-order response surface model with qualitative factors are presented as well as those for the second-order model. The results show that nearly D-optimal designs are obtained by the modified procedure and the improvement in D-efficiency is very significant. When the factors with the levels selected randomly from a population, they are treated as with random effects. Especially for the qualitative effects caused by the experimental units that the experimenter is not interested in, one should consider the model with random block effects. In this model, the observations on the same unit are assumed to be correlated and they are uncorrelated between different units. Then the mean response surface is still considered as second-order for quantitative factors but the covariance matrix of the observations is different from the identity matrix. In the fourth part of this dissertation, the locally D-optimal designs on a circular design region are proposed for given the value of the correlations. These optimal designs with the structures based on the regular polygons are similar to the D-optimal designs for the uncorrelated model.

Cyclodextrins (CD) are cyclic oligosaccharides composed of six to more than sixty glucose units. Large-ring cyclodextrins (LR-CD) are novel CD comprised of more than eight glucose units with cavity structures and sizes different from that of commercially available CD₆ – CD₈. LR-CD may offer unique molecular recognition properties and can be produced biocatalytically from starch using cyclodextrin glucanotransferase (CGTase, E.C. 2.4.1.19) in a short reaction time. LR-CD were isolated from glucose, CD₆ – CD₈ and other compounds by complexation of CD₆ – CD₈ as well as precipitation techniques. The yield of LR-CD (degree of polymerization from 9 to 21) was optimized using central composite design. Addition of polar organic solvents to the synthesis resulted in higher yields of LR-CD. LR-CD composed of 9 to 21 glucose units were successfully separated using reversed-phase of ODS-AQ chromatography and normal-phase of polyamine II chromatography. Maintaining optimized reaction conditions aided in a high yield of CD₉; it could be separated with reasonable yield using a single step of polyamine II chromatography. A co-grinding method helped to obtain higher solubilization levels of glibenclamide, vitamin A acetate and vitamin D₃ in CD₁₃, CD₁₀ and CD₁₁, respectively when compared to other CD. Vitamin K₁ was solubilized in distilled water with CD₆ – CD₁₃ using a co-precipitation method. When compared with other CD, CD₉ was seen to be the best solubilizer. The analysis of complexes using ESI MS showed spironolactone and glibenclamide complexed with CD₉ and CD₁₃, respectively.

Made available in DSpace on 2015-03-26T13:32:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1445397 bytes, checksum: 2e00a708ce4685a98f700f3d00d17d31 (MD5) Previous issue date: 2012-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work had the purpose of evaluating the performance of the rotational central composite design (RCCD) in relation to the estimated response surface parameters, under conditions of simulated experimental errors that provide high coefficients of variation. The big impulse of the response methodology was given by Box and Wilson (1951), who developed methods of process optimization in industrial researches. Within these methods, the RCCD may be mentioned as an economic design for the response surface, due to the reduced number of level combinations in the studied factors, when compared to the full factorial. However, it is known that these designs are efficient where experimental mistakes are usually small and the conditions of the experiment are easily controlled. However, given the reduced number of tests by the RCCD, it has become important to verify its potential in designing treatments to adjust response surfaces on experiments related to agrarian sciences, that present, naturally, larger random error. For such, the treatment designs, full factorial and rotational central composite have been used to plan the combinations between the coded levels of two factors (A and B). A second-order model has been established for two factors A and B without interaction among them, named true response surface. A full 5x5 factorial has been established, with the combinations between the coded levels of factors A and B and 40 repetitions per treatment. In total, 1000 experimental units have been built. Afterwards, 100 simulations have been made for the experimental errors ε present in the experiment under normal conditions with average zero and variations σε2. The parameter σε has been specified in 32, 48, 64 and 80, to provide the residual coefficients of variation (CV) equal to 25, 37, 50 and 60 %. The choice of these coefficients of variation has been made in order to include the classifications created by Ferreira (1991), quoted by Silva et al. (2011), and Pimentel Gomes (1985) for the agrarian areas. The observed values of Y have been obtained from the sum of the true values of Y ( ) obtained from the true response surface, with residuals ( ), generated by the simulation. In each type of design (RCCD and full factorial), three, six, nine and twelve repetitions per treatment have been established. According to the combinations between the types of treatment, coefficients of variation and number of repetitions per treatment, 100 adjustments of the response surface have been realized, from which the averages of the coefficient of determination, the average distances between the true and the estimated critical point (CPD) and between the coefficients of variation estimated and simulated (CVD), besides the success percentage and confidence interval of each parameter and the percentage of success from the response surface. Afterwards, a regression of these measures as been made, evaluated based on the design, coefficient of variation and number of repetitions per treatment. The superiority of performance of the full factorial in relation to the RCCD increase in relation to the increase of the CV and the reducing of the number of repetitions per treatment. The RCCD has been recommended under more controlled experimental conditions, for being a more economic treatment design. However, knowing the difficulty of controlling the random error on experiments for the agrarian areas, in experiments of this nature the full factorial or the RCCD were recommended with a larger number of repetitions per treatment. It has also been concluded that the increase of the CV prejudices the adjustment quality of the full factorial and mainly of the RCCD and this prejudice can be compensated with the increase in the number of repetitions per treatment. It has been seen that the adjustment quality provided by the treatment design does not depend only of their quantity, but mostly on the sufficient amount of experimental units to provide proper estimates of the effects of the known and unknown factors. / Esse trabalho teve como objetivo avaliar o desempenho do delineamento composto central rotacional (DCCR) em relação às estimativas dos parâmetros da superfície de resposta estimada, sob condições de erros experimentais simulados que proporcionam altos coeficientes de variação. O grande impulso da metodologia de resposta foi dado por Box e Wilson (1951), que desenvolveram métodos de otimização de processos em pesquisas industriais. Dentre esses métodos, pode-se citar o DCCR como um delineamento econômico para a superfície de resposta, devido ao número reduzido de combinações entre os níveis dos fatores estudados, quando comparado ao fatorial completo. No entanto, sabe-se que estes delineamentos são eficientes onde normalmente os erros experimentais são pequenos e as condições do experimento são mais facilmente controláveis. Portanto, dada a economia do número de ensaios pelo DCCR, tornou-se importante verificar o seu potencial em delinear tratamentos visando o ajuste de superfícies de respostas para experimentos ligados às ciências agrárias, que apresentam, naturalmente, maiores erros aleatórios. Para tanto, os delineamentos de tratamentos, fatorial completo e composto central rotacional foram utilizados para planejar as combinações entre os níveis codificados de dois fatores (A e B). Foi estabelecido um modelo de segunda ordem para dois fatores A e B sem interação entre eles, denominada de superfície de resposta verdadeira. Foi estabelecido um fatorial completo 5x5, com as combinações entre os níveis codificados dos fatores A e B e com 40 repetições por tratamento. No total, foram constituídas 1000 unidades experimentais. Posteriormente, foram feitas 100 simulações para os erros experimentais presentes no experimento sob distribuição normal com média zero e variância σε2. O parâmetro σε foi especificado em 32, 48, 64 e 80, para fornecer os coeficientes de variação residuais (CV) iguais a 25, 37, 50 e 62 %. A escolha de tais coeficientes de variação foi feita de modo a abranger as classificações criadas por Ferreira (1991), citado por Silva et al. (2011), e Pimentel Gomes (1985) para as áreas agrárias. Os valores observados de Y foram obtidos a partir da soma dos valores verdadeiros de Y ( ) obtidos a partir da superfície de resposta verdadeira, com os resíduos , gerados pela simulação. Em cada tipo de delineamento (DCCR e fatorial completo), foram estabelecidas três, seis, nove e doze repetições por tratamento. De acordo com as combinações entre os tipos de delineamentos, coeficientes de variação e número de repetições por tratamento, foram realizados 100 ajustes da superfície de resposta dos quais foram obtidas as médias do coeficiente de determinação, EQM, a distância média entre o ponto crítico verdadeiro e o estimado (DPC) e a diferença média entre os coeficientes de variação estimados e simulados (DCV), além da porcentagem de acerto e intervalo de confiança de cada parâmetro e a porcentagem de acerto da superfície de resposta. Posteriormente foi feita uma regressão dessas medidas avaliadas em função do delineamento, coeficiente de variação e número de repetições por tratamento. A superioridade do desempenho do fatorial completo em relação DCCR aumentou em função do aumento do CV e da diminuição do número de repetições por tratamento. Recomendou-se o DCCR sob condições experimentais mais bem controladas, por ser um delineamento de tratamento mais econômico. No entanto, sabendo do difícil controle do erro aleatório em experimentos das áreas agrárias, em experimentos dessa natureza recomendou-se o fatorial completo ou o DCCR com um número maior de repetições por tratamento. Conclui-se também que o aumento do CV prejudica a qualidade de ajuste do fatorial completo e principalmente a do DCCR e esse prejuízo pode ser compensado com o aumento do número de repetições por tratamento. Percebeu-se que a qualidade de ajuste proporcionada pelo delineamento de tratamento não depende só da quantidade dos mesmos, mas principalmente da quantidade de unidades experimentais suficientes para proporcionar estimativas adequadas dos efeitos dos fatores conhecidos e desconhecidos.