Tecnología y competitividad en la economía mundial. Factores e indicadores clave de actuación

Durante los últimos 30 años se han creado una gran cantidad de índices e indicadores para evaluar la práctica totalidad de los países bajo distintas premisas. La tesis parte de un análisis detallado de más de un centenar de estos índices diferenciados entre los enfocados al desarrollo y los enfocados a la competitividad económica (véase Módulo I anexo) y tras esto, dentro del estudio teórico nos hemos centrado en 35 indicadores relacionados con la tecnología (capítulo 3, apartado 3.3.). La justificación, el objetivo de la investigación y la estructura de la tesis se presenta en el capítulo 2. Respecto a la metodología, tal y como se plantea en la hipótesis (apartado 2.2.), se presentan los criterios de selección de seis grupos de países (EP, EPC, EC, ECI, EI y EM)1, que se van a evaluar. Posteriormente se plantea el Protocolo de Cálculo para el total de grupos seleccionados dentro de los periodos 2005-2006 y 2007-2008 y se realiza una profunda evaluación estadística como se plantea dentro de la coherencia estadística explicada en el apartado 3.4.4.5. (también se dispone de los cálculos dentro de los Módulos II, III, IV y V anexos). Tras la metodología establecemos la construcción de un índice sintético NRI(A) y, tras esto, estudiamos las relaciones así como la interpretación de los resultados (capítulo 4, apartado 4.1.). Una vez obtenidos los resultados realizamos la validación de los mismos para el periodo 2007-2015 (capítulo 4 - apartado 4.2. – y los Módulos VI y VII anexos). En el capítulo 5, evaluamos el nivel de preparación tecnológico y su relación con la competitividad para los seis grupos de países (véase desde los apartados 5.1.y 5.2.). Dentro de cada uno de los seis grupos de países, sabemos las variables que cualitativamente tienen que priorizarse para mejorar el nivel de preparación tecnológica de los mismos. Estas variables inicialmente son sesenta y ocho – año 2007-08 –, y al final de la implementación del método se reducen notablemente. Estas variables finales, llamadas Indicadores Clave de Actuación (ICA), se agrupan – vía análisis factorial – en Factores Clave de Actuación que nos simplifican lo planteado. Para cada grupo de países se realizan los conglomerados de acuerdo a sus valores dentro de las ICAs en busca de singularidades y se ha llevado a cabo un análisis minucioso en función de los Indicadores Clave de Actuación. La Tesis, plantea científicamente como podemos evaluar el nivel de preparación tecnológica y su relación con la competitividad, desde un índice sintético creado NRI(A), que contempla únicamente Indicadores Clave de Actuación (variables seleccionadas) a partir de las variables originales del Network Readiness Index (NRI(R)) . Por último se plantea dentro de las conclusiones, capítulo 6, diferentes líneas de investigación, desarrollando dos de ellas que se pueden encontrar en el Modulo VIII anexo. Por un lado presentamos una línea de investigación centrada en 29 economías africanas (EA) de las que disponemos información fidedigna y por otro lado una segunda línea en la que nos centramos en la evaluación de España respecto a sus naciones coetáneas. La principal voluntad de la presente tesis doctoral, es simplificar la evaluación del nivel de preparación tecnológica y la relación de esta con la competitividad a partir de la creación de un índice sintético propio NRI(A). ABSTRACT - During the last 30 years, many institutions have been evaluating and endless range of variables in practically all of the world´s economies. This Thesis is the product of a detail analysis of more than one hundred indicators / index, which we have divided into two parts: those focused on development and those focused on economic competitiveness (see module I annex). Secondly, in our theoretical research we have concentrated on those indicators, which are related to technology (chapters 3, section 3.3). The selection criteria of the six economic groups to be evaluated are included in our methodology, as mentioned in the hypothesis (see section 2.2.). Subsequently the calculation procedure is also presented for all of the groups selected between the periods 2005-2006 and 2007-2008. Next, we perform a statistical study, which is presented accordingly in the segment dealing with statistics, section 3.4.4.5. The calculations are provided in modules I, II, III, IV and V annex. After the methods segment of the Thesis, we develop our argument, in which we presented the explanation of the relations as well as the interpretation of the results. Also at the chapter 4 you can find the result validation from 2007 till 2015. Finally in chapters 6, we evaluate the conclusions for the six economic groups (see section 6.2.). The Thesis scientifically explains the way in which we evaluate economic competitiveness in 135 countries from a standpoint of strictly technological variables. Six groups of countries are evaluated, being divided by criteria, which homogenize the economies under review. We recognize that the variables of each economic group should be prioritized in order to better their competitiveness. Initially the group consisted of 68 variables, a number which was considerably reduced after the implementation of our methodology. Likewise, these final variables, dubbed “key performance indicators”, were grouped into factors (key performance factors), which greatly simplify the prioritization process. At the same time, conglomerates have been created for each economic group according to their value concerning the selected variables. A detailed country – by – country analysis of their positioning in each of the six groups was conducted for each of the mathematically selected key performance indicators. Finally, at the Conclusion we introduce new research lines and between them we focus on two research lines in which ones we are working with (see chapter 6). We basically try to apply the multivariable analysis method, the factorial analysis and the conglomerates to designed and implemented our method first in a geographically group of countries (Africa) and secondly to evaluate and develop the public policies for Spain for the development of its competitively, comparing Spain to his coetaneous countries in Europe (see Module VIII). The main objective of this Doctoral Thesis is to noticeably simplify the comparison of the Network Readiness Index and its relation with the economic competitiveness of the countries using a new synthetic index design by us.

The molecular role of the common gamma c subunit in signal transduction reveals functional asymmetry within multimeric cytokine receptor complexes.

The specific signal transduction function of the gamma c subunit in the interleukin (IL) 2, IL-4, IL-7, IL-9, and IL-15 receptor complexes remains undefined. The present structure-function analyses demonstrated that the entire cytoplasmic tail of gamma c could be functionally replaced in the IL-2 receptor (IL-2R) signaling complex by a severely truncated erythropoietin receptor cytoplasmic domain lacking tyrosine residues. Heterodimerization of IL-2R beta with either gamma c or the truncated erythropoietin receptor chain led to an array of specific signals normally derived from the native IL-2R despite the substitution of Janus kinase JAK2 for JAK3 in the receptor complex. These findings thus suggest a model in which the gamma c subunit serves as a common and generic "trigger" chain by providing a nonspecific Janus kinase for signaling program initiation, while signal specificity is determined by the unique "driver" subunit in each of the gamma c- containing receptor complexes. Furthermore, these results may have important functional implications for the asymmetric design of many cytokine receptor complexes and the evolutionary design of receptor subfamilies that share common trigger or driver subunits.

Doseamento microbiológico de neomicina e bacitracina - desenvolvimento e validação de método rápido em microplacas

Os ensaios microbiológicos são utilizados para avaliar a atividade antimicrobiana desde a descoberta do uso dos antibióticos. Apesar dos ensaios microbiológicos serem amplamente empregados para determinação da potência de antibióticos em formas farmacêuticas, uma vez que fornecem a medida da atividade biológica, apresentam limitações quanto a baixa reprodutibilidade e tempo de análise. O objetivo deste trabalho foi desenvolver, otimizar e validar ensaio colorimétrico rápido em microplaca para determinar a potência da neomicina e bacitracina em produtos farmacêuticos. Metodologias de análise fatorial e análise de superfície de resposta foram utilizadas no desenvolvimento e otimização da escolha do microrganismo, da composição do meio de cultura, da proporção de inóculo, e das concentrações de cloreto de trifeniltetrazólio e dos antibióticos. Os métodos otimizados foram validados pela avaliação da linearidade, precisão, exatidão e robustez. Análise estatística mostrou equivalência entre o método de difusão em ágar e o método colorimétrico rápido em microplaca para ambos antibióticos. Além disso, o ensaio em microplaca apresentou vantagens em relação à reprodutibilidade, sensibilidade, tempo de incubação e quantidades necessárias de meio de cultura e soluções para ambos os antibióticos.

Análise de flavanóides por cromatografia líquida de alta eficiência e eletroforese capilar - otimização de separação e aplicações tecnológicas

No presente trabalho foram estudadas as separações de 18 flavonóides (9 agliconas e 9 glicosídeos) pelas técnicas de Cromatografia Líquida de Alta Eficiência em fase reversa (RP-HPLC) e Cromatografia Micelar Eletrocinética em fluxo reverso (RF-Meck). Em ambas as técnicas foram avaliados solventes puros (metanol, acetonitrila e tetrahidrofurano) e suas misturas como formas de promover a variação de seletividade, através da modificação da fase móvel em HPLC, e da natureza do aditivo orgânico em RF-Meck. Nos estudos efetuados em HPLC utilizando-se gradiente, pode-se comprovar a possibilidade da modelagem do fator de retenção em funçã da proporção de solvente utilizados (MeOH, ACN, THF e suas misturas). Pode-se ainda, com base nos dados de retenção e na análise hierárquica de c1usters, diferenciar quatro diferentes grupos de sistemas cromatográficos com diferentes seletividades para flavonóides agliconas, e outros quatro com diferentes seletividades para glicosídeos. Os sistemas cromatográficos mais ortogonais (cada um pertencente a um grupo de seletividade) foram aplicados na separação de uma planta modelo (Azadirachta indica), de onde pode-se escolher a fase móvel mais seletiva para se otimizar a separação dos flavonóides glicosilados presentes nas folhas desta planta. No método final otimizado pode-se identificar e quantificar cinco dos flavonóides majoritários presentes, sendo três glicosídeos de quercetina (rutina, isoquercitrina e quercitrina) e dois glicosídeos de kaempferol (astragalin e nicotiflorin), em amostras de duas diferentes procedências (Piracicaba-SP e Silvânia-GO). Nos estudos envolvendo a separação dos dezoito flavonóides por RFMEKC pode-se comprovar diferenças significativas de seletividade quando se varia a natureza do solvente orgânico utilizado como aditivo, além de se observar tendências na migração em função das propriedades do solvente adicionado e da estrutura molecular do flavonóide. O solvente de menor eficiência para separação dos flavonóides foi o MeOH. Através da análise dos eletroferogramas obtidos através de um planejamento experimental de misturas, e das trocas de pares críticos observadas nos vários eletrólitos utilizados, obteve-se um método de separação com apenas um par crítico em menos de 12 minutos de corrida. O coeficiente de variação obtido para o fator de retenção foi de 1,5% e para área de 3%, considerando-se cinco injeções. O método desenvolvido foi aplicado com sucesso na identificação dos flavonóides majoritários presentes na planta modelo (Neem), obtendo-se o mesmo resultado do estudo anterior. Como forma de avaliar a concentração de flavonóides totais presentes em espécies vegetais é comum a análise de extratos após hidrólise ácida (conversão de todos glicosídeos em agliconas). Desta forma otimizou-se uma metodologia de separação em RP-HPLC de 8 flavonóides agliconas comumente presentes em alimentos e extratos vegetais de uso cosmético. A otimização foi efetuada mediante um planejamento experimental de misturas, para escolha da fase móvel mais seletiva, e de um planejamento fatorial composto central, para otimização das condições de gradiente. O método obtido foi o mais rápido já visto dentro da literatura consultada. A separação em linha de base foi efetuada em menos de 15 minutos, com coeficientes de variação de área entre 0,1 e 1,8%, coeficiente de correlação de 0,9993 a 0,9994 na faixa de 5 a 100 µg/mL, e limites de quantificação estimados na faixa de 0,1 a 0,21µg/mL. O método desenvolvido foi aplicado na otimização das condições de hidrólise de um extrato de Neem. A otimização foi efetuada através de metodologia de superfície de resposta, levando-se em consideração a concentração de ácido adicionada, o tempo de reação, a temperatura, e a concentração de um antioxidante (ácido ascórbico) adicionado. O resultado da otimização foi uma metodologia de hidrólise com tempo de reação igual a 5 minutos, utilizando-se 1,4 mol/L de HCI, 119°C e 500 µg/mL de ácido ascórbico. Através das metodologias de análise e de hidrólise desenvolvidas pode-se constatar a presença e quantificar no extrato de Neem os flavonóides agliconas quercetina, kaempferol e miricetina. Com o objetivo de se avaliar quais os componentes presentes em extratos vegetais são os responsáveis pelo poder antioxidante atribuído a determinadas plantas, foi montado um sistema de avaliação de poder antioxidante \"on-line\" com reação pós-coluna em HPLC (baseado na literatura) utilizando-se como \"radical livre modelo\" o ABTS. A análise da planta modelo (Neem) neste sistema mostrou que os flavonóides glicosilados identificados nas partes anteriores deste trabalho são os responsáveis pelo poder antioxidante atribuído a esta planta. De posse desta informação, e visando a obtenção de extratos para aplicações cosméticas com poder antioxidante, modelou-se a extração dos flavonóide do Neem em função da composição do solvente extrator (água, etanol , propilenoglicol e suas misturas), de acordo com um planejamento simplex centróide ampliado. Além da previsão da concentração dos princípios ativos pode-se ainda prever outras propriedades dos extratos obtidos, tais como, índice de refração e densidade, muitas vezes constituintes de especificações técnicas de acordo com as aplicações a que se destinam (cremes, xampús, etc).

Estudo da degradação do dietil ftalato por processo eletroquímico com ânodo dimensionalmente estável em sistemas aquosos

Os ésteres de ftalato (PAEs) são compostos produzidos em grandes quantidades, amplamente utilizados industrialmente como agentes plastificantes. Seus resíduos são lixiviados pela água tornando-se poluentes orgânicos persistentes (POPs) no meio ambiente aquoso, além de apresentar características de interferência endócrina. O dietil ftalato (DEP) é frequentemente encontrado nas amostras ambientais, pois possui elevada solubilidade na água e pode ser gerado durante a degradação de outros PAEs. Assim, este trabalho teve como objetivo a degradação do dietil ftalato em meio aquoso por método eletroquímico utilizando um ânodo dimensionalmente estável (ADE) comercial representado como Ti/Ru0,3Ti0,7O2 em uma célula do tipo filtro-prensa. As eletrólises foram de 120 minutos contendo uma concentração inicial de 100,3 mg L-1 de DEP, pH inicial igual a 3, a temperatura em 25 °C e vazão em 250 mL min-1. Os experimentos foram feitos utilizando planejamento fatorial do tipo 32 com duas réplicas no ponto central, apresentando como variáveis independentes a densidade de corrente (10, 25 e 40 mA cm-2) e o logaritmo em base 10 da forca iônica do eletrólito suporte, NaCl e Na2SO4 (µ = 0,05, 0,15 e 0,5 mol L-1), com o intuito de estudar o efeito da densidade de corrente, concentração e natureza do eletrólito para determinar a melhor condição de degradação do dietil ftalato. O monitoramento da concentração do DEP foi feito com cromatografia líquida de alta eficiência (CLAE) e a mineralização foi acompanhada pelas análises de carbono orgânico total (COT). Foram obtidas maiores porcentagens de remoção e mineralização com uso das maiores densidades de corrente e na presença de altas concentrações de NaCl em comparação com Na2SO4. Dessa maneira, se obteve remoção de 63,2 % e mineralização de 63,9 % em solução 0,5 mol L-1 NaCl e densidade de corrente de 40 mA cm-2, enquanto que para Na2SO4 (µ = 0,5 mol L-1) e 40 mA cm-2 foi removido 51,3 % e mineralizado 53,0 % de DEP. O mecanismo de degradação de DEP foi determinado em meio de NaCl e Na2SO4, através de CLAE-MS nas condições citadas anteriormente, identificando-se os íons moleculares de m/z 149 e 177 em ambos eletrólitos, correspondentes ao anidrido ftálico protonado e ao aduto do anidrido ftálico com C(2)H(5)(+) respectivamente, íons característicos da fragmentação do DEP, além do íon m/z 239 em Na2SO4 correspondente ao dietil 3-hidroxiftalato. A degradação do DEP acontece através da cadeia alifática.

Optimum Design of Electromagnets for Magnetic Levitation of Transport Systems based on the Inverse Problem Solutions

Article is devoted to design of optimum electromagnets for magnetic levitation of transport systems. The method of electromagnets design based on the inverse problem solution of electrical equipment is offered. The method differs from known by introducing a stage of minimization the target functions providing the stated levitation force and magnetic induction in a gap, and also the mass of an electromagnet. Initial values of parameters are received, using approximate formulas of the theory of electric devices and electrical equipment. The example of realization of a method is given. The received results show its high efficiency at design. It is practical to use the offered method and the computer program realizing it as a part of system of the automated design of electric equipment for transport with a magnetic levitation.

Validation of a food-frequency questionnaire assessment of carotenoid and vitamin E intake using weighed food records and plasma biomarkers: The method of triads model

Background: Reliability or validity studies are important for the evaluation of measurement error in dietary assessment methods. An approach to validation known as the method of triads uses triangulation techniques to calculate the validity coefficient of a food-frequency questionnaire (FFQ). Objective: To assess the validity of an FFQ estimates of carotenoid and vitamin E intake against serum biomarker measurements and weighed food records (WFRs), by applying the method of triads. Design: The study population was a sub-sample of adult participants in a randomised controlled trial of beta-carotene and sunscreen in the prevention of skin cancer. Dietary intake was assessed by a self-administered FFQ and a WFR. Nonfasting blood samples were collected and plasma analysed for five carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, lycopene) and vitamin E. Correlation coefficients were calculated between each of the dietary methods and the validity coefficient was calculated using the method of triads. The 95% confidence intervals for the validity coefficients were estimated using bootstrap sampling. Results: The validity coefficients of the FFQ were highest for alpha-carotene (0.85) and lycopene (0.62), followed by beta- carotene (0.55) and total carotenoids (0.55), while the lowest validity coefficient was for lutein (0.19). The method of triads could not be used for b- cryptoxanthin and vitamin E, as one of the three underlying correlations was negative. Conclusions: Results were similar to other studies of validity using biomarkers and the method of triads. For many dietary factors, the upper limit of the validity coefficients was less than 0.5 and therefore only strong relationships between dietary exposure and disease will be detected.

Application of central composite rotatable design to modelling the effect of some operating variables on the performance of the three-product cyclone

The central composite rotatable design (CCRD) was used to design an experimental program to model the effects of inlet pressure, feed density, and length and diameter of the inner vortex finder on the operational performance of a 150-min three-product cyclone. The ranges of values of the variables used in the design were: inlet pressure: 80-130 kPa, feed density: 30 60%; length of IVF below the OVF: 50-585 mm; diameter of IVF: 35-50 mm. A total of 30 tests were conducted, which is 51 less; an that required for a three-level full factorial design. Because the model allows confident performance prediction by interpolation over the range of data in the database, it was used to construct response surface graphs to describe the effects of the variables on the performance of the three-product cyclone. To obtain a simple and yet a realistic model, it was refitted using only the variable terms that are significant at greater than or equal to 90% confidence level. Considering the selected operating variables, the resultant model is significant and predicts the experimental data well. (c) 2005 Elsevier B.V. All rights reserved.

Design of a compact ultra-wideband antenna

A simple method for the design of ultra-wideband antennas in planar format is presented. This method is demonstrated for a high-dielectric-constant substrate material, which allows for a considerable antenna size reduction. Simulations are performed using Ansoft's High-Frequency Structure Simulator (HFSS) for antennas assuming Du-Pont951 (epsilon(r) = 7.8) and RT6010LM (epsilon(r) = 10.2) substrates. For the 1-mm-thick DuPont951, the designed antenna with 22 X 28 nun dimensions features a 10-dB return-loss band width front 2.7 GHz to more than 15 GHz. For the 0.64-mm-thick RT6010LM a 20 X 26 nun antenna exhibits a 10-dB return loss bandwidth from 3.1 to 15 GHz. Both antennas feature nearly omnidirectional properties across the whole 10-dB return-loss bandwidth. The validity of the presented UWB antenna design strategy is confirmed by measurements performed on a prototype developed on RT6010LM substrate. (c) 2006 Wiley Periodicals, Inc.

Can we learn more from fewer seeds?

The vital role that 'design of experiment' (DOE) plays when investigating dormancy, germination and potentially influential factors is discussed. The Taguchi analysis, developed by Dr. Genichi Taguchi, is a special application and analysis of the fractional factorial aimed at achieving maximum information from minimum effort and resources.

Data methods in optometry Part 9: experimental design and analysis of variance

The key to the correct application of ANOVA is careful experimental design and matching the correct analysis to that design. The following points should therefore, be considered before designing any experiment: 1. In a single factor design, ensure that the factor is identified as a 'fixed' or 'random effect' factor. 2. In more complex designs, with more than one factor, there may be a mixture of fixed and random effect factors present, so ensure that each factor is clearly identified. 3. Where replicates can be grouped or blocked, the advantages of a randomised blocks design should be considered. There should be evidence, however, that blocking can sufficiently reduce the error variation to counter the loss of DF compared with a randomised design. 4. Where different treatments are applied sequentially to a patient, the advantages of a three-way design in which the different orders of the treatments are included as an 'effect' should be considered. 5. Combining different factors to make a more efficient experiment and to measure possible factor interactions should always be considered. 6. The effect of 'internal replication' should be taken into account in a factorial design in deciding the number of replications to be used. Where possible, each error term of the ANOVA should have at least 15 DF. 7. Consider carefully whether a particular factorial design can be considered to be a split-plot or a repeated measures design. If such a design is appropriate, consider how to continue the analysis bearing in mind the problem of using post hoc tests in this situation.

Computer aided design and manufacture of form-rolls

Cold roll forming of thin-walled sections is a very useful process in the sheet metal industry. However, the conventional method for the design and manufacture of form-rolls, the special tooling used in the cold roll forming process, is a very time consuming and skill demanding exercise. This thesis describes the establishment of a stand-alone minicomputer based CAD/CAM system for assisting the design and manufacture of form-rolls. The work was undertaken in collaboration with a leading manufacturer of thin-walled sections. A package of computer programs have been developed to provide computer aids for every aspect of work in form-roll design and manufacture. The programs have been successfully implemented, as an integrated CAD/CAM software system, on the ICL PERQ minicomputer with graphics facilities. Thus, the developed CAD/CAM system is a single-user workstation, with software facilities to help the user to perform the conventional roll design activities including the design of the finished section, the flower pattern, and the form-rolls. A roll editor program can then be used to modify, if required, the computer generated roll profiles. As far as manufacturing is concerned, a special-purpose roll machining program and postprocessor can be used in conjunction to generate the NC control part-programs for the production of form-rolls by NC turning. Graphics facilities have been incorporated into the CAD/CAM software programs to display drawings interactively on the computer screen throughout all stages of execution of the CAD/CAM software. It has been found that computerisation can shorten the lead time in all activities dealing with the design and manufacture of form-rolls, and small or medium size manufacturing companies can gain benefits from the CAD/CM! technology by developing, according to its own specification, a tailor-made CAD/CAM software system on a low cost minicomputer.

An agent-based model of team coordination and performance

This research is based on the premises that teams can be designed to optimize its performance, and appropriate team coordination is a significant factor to team outcome performance. Contingency theory argues that the effectiveness of a team depends on the right fit of the team design factors to the particular job at hand. Therefore, organizations need computational tools capable of predict the performance of different configurations of teams. This research created an agent-based model of teams called the Team Coordination Model (TCM). The TCM estimates the coordination load and performance of a team, based on its composition, coordination mechanisms, and job’s structural characteristics. The TCM can be used to determine the team’s design characteristics that most likely lead the team to achieve optimal performance. The TCM is implemented as an agent-based discrete-event simulation application built using JAVA and Cybele Pro agent architecture. The model implements the effect of individual team design factors on team processes, but the resulting performance emerges from the behavior of the agents. These team member agents use decision making, and explicit and implicit mechanisms to coordinate the job. The model validation included the comparison of the TCM’s results with statistics from a real team and with the results predicted by the team performance literature. An illustrative 26-1 fractional factorial experimental design demonstrates the application of the simulation model to the design of a team. The results from the ANOVA analysis have been used to recommend the combination of levels of the experimental factors that optimize the completion time for a team that runs sailboats races. This research main contribution to the team modeling literature is a model capable of simulating teams working on complex job environments. The TCM implements a stochastic job structure model capable of capturing some of the complexity not capture by current models. In a stochastic job structure, the tasks required to complete the job change during the team execution of the job. This research proposed three new types of dependencies between tasks required to model a job as a stochastic structure. These dependencies are conditional sequential, single-conditional sequential, and the merge dependencies.

The effects of semantic and syntactic instruction on user performance and satisfaction in search user interface design

The design of interfaces to facilitate user search has become critical for search engines, ecommercesites, and intranets. This study investigated the use of targeted instructional hints to improve search by measuring the quantitative effects of users' performance and satisfaction. The effects of syntactic, semantic and exemplar search hints on user behavior were evaluated in an empirical investigation using naturalistic scenarios. Combining the three search hint components, each with two levels of intensity, in a factorial design generated eight search engine interfaces. Eighty participants participated in the study and each completed six realistic search tasks. Results revealed that the inclusion of search hints improved user effectiveness, efficiency and confidence when using the search interfaces, but with complex interactions that require specific guidelines for search interface designers. These design guidelines will allow search designers to create more effective interfaces for a variety of searchapplications.

Estudo da capacidade de remoção de óleo solúvel, em águas produzidas, por bentonitas hidrofobizadas

In this study we evaluated the capacity removal of PAHs in an oily solution between the bentonite hydrofobized with linseed oil and paraffin with natural bentonite. Analyses of natural bentonite and hydrofobized were made by the characterization techniques: (1) Thermogravimetric Analysis (TGA), which aimed to evaluate the thermal events due to mass loss, both associated with the exit of moisture and decomposition of clay as due to hidrofobizante loss agent. (2) Analysis of X-ray diffraction (XRD) in order to determine the mineralogical phases that make up the structure of clay and (3) Spectrophotometry in the infrared region used to characterize the functional groups of both the matrix mineral (bentonite) and the hidrofobizantes agents (linseed oil and paraffin). We used a factorial design 24 with the following factors; hidrofobizante, percent hidrofobizante, adsorption time and volume of the oily solution. Analyzing the factorial design 24 was seen that none of the factors apparently was more important than the others and, as all responses showed significant values in relation to the ability of oil removal was not possible to evaluate a difference in the degree of efficiency the two hidrofobizantes. For the new study compared the efficiency of the modified clay, with each hidrofobizante separately in relation to their natural form. As such, there are four new factorial designs 23 using natural bentonite as a differentiating factor. The factors used were bentonite (with and without hydrophobization), exposure time of the adsorbent material to the oily solution and volume of an oily solution, trying to interpret how these factors could influence the process of purifying water contaminated with PAHs. Was employed as a technique for obtaining responses to fluorescence spectroscopy, as already known from literature that PAHs, for presenting combined chains due to condensation of the aromatic rings fluoresce quite similar when excited in the ultraviolet region and as an auxiliary technique to gas chromatography / mass spectrometry (GC-MS) used for the analysis of PAHs in order to complement the study of fluorescence spectroscopy, since the spectroscopic method only allows you an idea of total number of fluorescent species contained in the oil soluble. The result shows an excellent adsorption of PAHs and other fluorescent species assigned to the main effect of the first factor, hydrophobization for the first planning 23 BNTL 5%, for 93% the sixth stop in the second test (+-+),factorial design 23 BNTL 10%, the fourth test (++-) with 94.5% the third factorial design 23 BNTP 5%, the second test (+--) with 91% and the fourth and final planning 23 BNTP 10%, the last test ( + + +) with 88%. Compared with adsorption of bentonite in its natural form. This work also shows the maximum adsorption of each hidrofobizante