Reutilização das águas de tingimento utilizando a Nanofiltração

Este trabalho na área dos processos físicos de separação por membranas, nomeadamente, a nanofiltração (NF), tem como objectivo principal a recuperação dos efluentes resultantes das águas da 3ª lavagem utilizadas na operação de tingimento de fibras de algodão, com corantes reactivos. Estão inerentes as problemáticas: da escassez da água como matéria-prima na vertente de água potável; da diminuição de efluentes que necessitam de tratamentos devido à sua carga poluente; da recuperação sempre que seja viável dos produtos químicos adicionados nesta fase de tratamento das fibras de algodão e por último e não menos importante, da energia contida nestes efluentes que vão para o esgoto a temperaturas na ordem dos 50 ºC. A metodologia adoptada na realização deste trabalho consistiu, inicialmente num estudo sobre os trabalhos realizados até hoje nesta área, seguindo-se a recolha dos efluentes na empresa ―Estamparia Têxtil Adalberto Pinto da Silva, S.A.‖ (ETAPS) e posterior estudo da recuperação dos efluentes em causa pelo processo de NF utilizando a membrana NF270-2540 da empresa FILMTEC. Os efluentes estudados no presente trabalho continham corantes reactivos sendo um corante azul-claro (CAC) de composição (Amarelo Bril Remazol GL 150% + Azul Brilhante Remazol BB 133% + Azul Turqueza Remazol G) e o outro corante azul-marinho (CAM) de composição (Preto Remazol B 133% + Vermelho Remazol RGB + Amarelo Ouro Remazol RGB). Estes estudos de recuperação compreenderam basicamente 3 fases: caracterização do efluente recolhido na empresa; tratamento desse efluente utilizando uma instalação piloto de NF de fluxo cruzado ou também conhecido por membrana de fluxo tangencial instalado no Laboratório de Tecnologia (LT) do Instituto Superior de Engenharia do Porto (ISEP), e caracterização dos permeados e dos rejeitados obtidos. A análise de resultados do presente trabalho permitiu concluir ser possível a recuperação e reutilização das 3ª águas de lavagem do processo de tingimento quando tratadas pelo processo de NF a pressões de operação de 6 bar. Nestas circunstâncias os permeados obtidos (tanto no efluente com corante azul-claro como no efluente com corante azul-marinho) apresentam valores, em todos os parâmetros estudados, significativamente abaixo dos valores limites recomendáveis para uma água de abastecimento na Industria Têxtil (IT). Salienta-se reduções mais expressivas nos permeados do corante CAM, com vários parâmetros a sofrerem reduções no intervalo de 98 a 100%, nomeadamente, na cor, turvação, CQO, dureza total, alumínio e manganês. Os resultados obtidos para as pressões de operação de 4 e 8 bar mostram alguns parâmetros com valores acima dos recomendados para uma água de abastecimento na Indústria Têxtil, nomeadamente a cor no corante CAC quando se opera a 4 bar e no corante CAM quando se opera a 8 bar e os sulfatos e ferro no CAM à pressão de 4 bar. Estes resultados mostram ser possível a reutilização da água na própria instalação industrial, trazendo um benefício económico e ambiental, pela redução no consumo de água fresca e energia, além da redução do volume de efluentes que necessitam ser tratados, estando na mesma linha de pensamento de Gross et al (1999), que refere que o uso de membranas para o tratamento de efluentes do processo de tingimento tem como principal objectivo a viabilidade económica, a redução no consumo de água, de sais, de corantes e energia, bem como, a redução do volume de efluentes a ser tratado.

Avaliação dos tratamentos eletroquímico e fotoeletroquímico na degradação de corantes têxteis

This paper presents the study of the oxidation of three textile dyes (Remazol black B, Remazol Brilliant Orange 3R and Remazol Golden Yellow RNL) using electrochemical and photoelectrochemical methods. In both methods, electrolysis experiments were performed at a current density of 50 mA cm-2 in an aqueous solution of each dye (30 mg L-1), using a photoelectrochemical flow-cell. For all the dyes studied, the photoelectrochemical method was demonstrated to be more efficient than the electrochemical one. Photoelectrochemical oxidation resulted in complete decoloration after 90 min of electrolysis and total organic carbon (TOC) removal reached up to 36%. It was observed that the dyes presenting chromophores at higher wavelengths are removed the quickest, which indicates that photosensitised (photoassisted) oxidation occurs. The level of color was reduced to levels below the standards presented in the literature, which indicates the viability of the photoelectrochemical process as part of the treatment of textile effluents.

Influence of neodymium ions on photocatalytic activity of TiO(2) synthesized by sol-gel and precipitation methods

Titanium dioxide with and without the addition of neodymium ions was prepared using sol-gel and precipitation methods. The resulting catalysts were characterized by thermal analysis, X-ray diffraction and BET specific surface area. Neodymium addition exerted a remarkable influence on the phase transition temperature and the surface properties of the TiO(2) matrix. TiO(2) samples synthesized by precipitation exhibit an exothermic event related from the amorphous to anatase phase transition at 510 degrees C, whereas in Nd-doped TiO(2) this transition occurred at 527 degrees C. A similar effect was observed in samples obtained using sol-gel method. The photocatalytic reactivity of the catalysts was evaluated by photodegradation of Remazol Black B (RB) under ultraviolet irradiation. Nd-doped TiO(2) showed enhanced photodegradation ability compared to undoped TiO(2) samples, independent of the method of synthesis. In samples obtained by sol-gel, RB decoloration was enhanced by 16% for TiO(2) doped with 0.5% neodymium ions. (C) 2010 Elsevier B.V. All rights reserved.

Obtenção de fotocatalisadores magnéticos a partir de resíduos industriais e TiO2 para a degradação de contaminantes orgânicos

In this work, magnetic photocatalysts were synthesized containing differents levels of TiO2 (40, 60 e 80%) supported at the supporter of C/LV, forming the photocatalysts 40, 60, 80Ti/C/LV, using tar pitch as carbon (C) source and red mud (LV) as iron source. The prepared magnetic photocatalysts and TiO2 were used to degrade the Remazol Black textile dye (PR5) and the organic material present in samples of a textile dye effluent. The characterization of photocatalysts by Raman, X-Ray Diffraction, Transmission Electron Micoscope and Scanning, Energy Dispersive X-ray Spectrometry, Termogravimetry and Elemental Analysis, confirms the presence of carbon and magnetite in support C/LV and the presence of TiO2 in prepared photocatalysts. The photocatalytic reactions with TiO2 were analyzed by different experimental conditions, such as: mass of TiO2 (30-240 mg), solution pH (2-10), light intensity (0.871 and 1.20 mWcm-2), type of radiation (UV and sunlight-1.420 mWcm-2), radiation incidence area (44.2 to 143.1 cm2) and dissolved oxygen (OD, 1.9 and 7.6 mg L- 1). Results showed that reactions with the following conditions: 220 mg of TiO2, pH 10, solar radiation, 7.6 mg L-1 of OD and an incidence area of radiation of 143.1 cm2 showed the best results for degradation of PR5 dye. Photocatalytic reactions with magnetic photocatalysts for degrading PR5 shows that efficiency increases with TiO2 content in the C/LV support, where, above 60% of TiO2, there was not significant increase in reaction velocity. In addition, solar radiation has proved to be advantageous for photocatalytic reactions. In order to verify the presence of a non-magnetic fraction in the photocatalyst 60Ti/C/LV0, magnetic separation was proceeded. The characterizations of the magnetic (FM) and nonmagnetic (NMF) fraction confirmed that about 25% of TiO2 did not fixed in 60Ti/C/LV photocatalyst. Results of photocatalytic reactions with FM and FNM showed that both phases have photocatalytic activity for degradation of PR5. The reactions executed for the degradation of organic matter present in the actual sample of textile effluent showed that TiO2 and magnetic photocatalyst 60Ti/C/ LV have better results for color removal (85 to 35%), soluble solids ( 11 and 3%), DQO (90 and 86%) and turbidity (94 and 11%) than the treatment done by the textile industry. Sedimentation kinetics tests in presence of a magnet showed that photocatalysts are separated faster from aqueous environment than pure TiO2. Obtained results showed that magnetic photocatalysts have excellent photocatalytic activity and can be separated from the reaction environment on a simple and quick way when a magnetic field is applied.

A comparison of skeletal, dentoalveolar and soft tissue characteristics in white and black Brazilian subjects

OBJECTIVE: This study aimed to compare skeletal, dentoalveolar and soft tissue characteristics in white and black Brazilian subjects presenting normal occlusions. MATERIAL AND METHODS: The sample comprised the lateral cephalograms of 106 untreated Brazilian subjects with normal occlusion, divided into two groups: Group 1- 50 white subjects (25 of each gender), at a mean age of 13.17 years (standard deviation 1.07); and Group 2- 56 black subjects (28 of each gender), at a mean age of 13.24 years (standard deviation 0.56). Variables studied were obtained from several cephalometric analyses. Independent t tests were used for intergroup comparison and to determine sexual dimorphism. RESULTS: black subjects presented a more protruded maxilla and mandible, a smaller chin prominence and a greater maxillomandibular discrepancy than white subjects. Blacks presented a more horizontal craniofacial growth pattern than whites. Maxillary and mandibular incisors presented more protruded and proclined in black subjects. The nasolabial angle was larger in whites. Upper and lower lips were more protruded in blacks than in whites. CONCLUSIONS: The present study found a bimaxillary skeletal, dentoalveolar and soft tissue protrusion in black Brazilian subjects compared to white Brazilian subjects, both groups with normal occlusion. Upper and lower lips showed to be more protruded in blacks, but lip thickness was similar in both groups.

Sensory evaluation of black instant coffee beverage with some volatile compounds present in aromatic oil from roasted coffee

The oil obtained from Brazilian roasted coffee by supercritical CO2 extraction shows considerable aromatic properties, mainly composed by five aromatic compounds, 2-methylpyrazine; 2-furfurylalcohol, 2,5-dimethylpyrazine; γ-butyrolactone and 2-furfurylacetate. Sensory analyses were used to verify the influence of a mixture of these important classes of aromatic coffee compounds (pyrazines, furans and lactones) and of the roasted coffee aromatic oil on the coffee aroma and flavour of black instant freeze and spray-dried coffee beverages. In the acceptance evaluation of the aroma, the samples prepared with freeze-dried instant coffee without the mixture of volatile compounds (sample 4) were not significantly different from the freeze-dried instant coffee in which the aromatic coffee oil was added (sample 5) and from the sample prepared with freeze-dried coffee in which the mixture of the five volatile was added (sample 3), coincidentally from the same drying process. Therefore, sample (3) did not differ from samples prepared with spray dried instant coffee without (sample 1) and to which (sample 2) the mixture of volatile was added. Therefore, with respect to this attribute, the addition of this mixture did not interfere in this drink acceptance. Taking into consideration the flavor, samples prepared with freeze-dried instant coffee in which the aromatic coffee oil was added (5) and the samples with (3) and without (4) the mixture of the five volatile was added did not differ significantly, however sample (4) did not differ from samples (1) and (2). Regarding this attribute, the addition of the aromatic oil of roasted coffee or a mixture of volatile in samples of freeze-dried instant coffee had a better acceptance than those dried by spray dryer (1) and (2). Thus, the enrichment of drinks with the aromatic oil of roasted coffee, or even with the mixture of the five components did not influence the consumer acceptance with respect to the aroma, but exerts influence with respect to flavour.

Nyssomyia intermedia (Lutz & Neiva) and Nyssomyia neivai (Pinto) (Diptera, Psychodidae, Phlebotominae) in a sympatric area: seasonal and nocturnal hourly rhythm in black and white modified Shannon traps

Captures with black and white Shannon traps were undertaken to identify aspects of the behavior of the two cryptic and sympatric species implicated as vectors of cutaneous leishmaniasis, Nyssomyia intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926). The traps were installed side by side, monthly, from July 2001 to June 2002, from 18 to 07 hours, in a peridomicile of Iporanga municipality, state of São Paulo, Brazil. A total of 2,142 specimens were captured, Ny. intermedia (47.4%) and Ny. neivai (50.5%). The white trap was more attractive to both sexes of both species. Males of Ny. neivai predominated (70%) over those of Ny. intermedia on the two traps; on the black trap, the females of Ny. intermedia predominated (63.3%) over those of Ny. neivai (36.7%). Seventy percent of the specimens of both species were captured between 18 and 24 h. Females of Ny. intermedia presented the highest peak at 19-20 h, and those of Ny. neivai at 20-21 h. The highest hourly average for females of Ny. intermedia on the black trap occurred in the winter and that for males in the summer. For Ny. neivai, both sexes predominated in the summer. The two species probably transmit the cutaneous leishmaniasis in the area due to their great predominance.

Black holes and wormholes in AdS branes

In this work we have derived a class of geometries which describe black holes and wormholes in Randall-Sundrum-type brane models, focusing mainly on asymptotically anti-de Sitter backgrounds. We show that by continuously deforming the usual four-dimensional vacuum background, a specific family of solutions is obtained. Maximal extensions of the solutions are presented, and their causal structures are discussed.

Gravitational signature of Schwarzschild black holes in dynamical Chern-Simons gravity

Dynamical Chern-Simons gravity is an extension of general relativity in which the gravitational field is coupled to a scalar field through a parity-violating Chern-Simons term. In this framework, we study perturbations of spherically symmetric black hole spacetimes, assuming that the background scalar field vanishes. Our results suggest that these spacetimes are stable, and small perturbations die away as a ringdown. However, in contrast to standard general relativity, the gravitational waveforms are also driven by the scalar field. Thus, the gravitational oscillation modes of black holes carry imprints of the coupling to the scalar field. This is a smoking gun for Chern-Simons theory and could be tested with gravitational-wave detectors, such as LIGO or LISA. For negative values of the coupling constant, ghosts are known to arise, and we explicitly verify their appearance numerically. Our results are validated using both time evolution and frequency domain methods.

Quasinormal modes of black holes in anti-de Sitter space: A numerical study of the eikonal limit

Using series solutions and time-domain evolutions, we probe the eikonal limit of the gravitational and scalar-field quasinormal modes of large black holes and black branes in anti-de Sitter backgrounds. These results are particularly relevant for the AdS/CFT correspondence, since the eikonal regime is characterized by the existence of long-lived modes which (presumably) dominate the decay time scale of the perturbations. We confirm all the main qualitative features of these slowly damped modes as predicted by Festuccia and Liu [G. Festuccia and H. Liu, arXiv:0811.1033.] for the scalar-field (tensor-type gravitational) fluctuations. However, quantitatively we find dimensional-dependent correction factors. We also investigate the dependence of the quasinormal mode frequencies on the horizon radius of the black hole (brane) and the angular momentum (wave number) of vector- and scalar-type gravitational perturbations.

The Role of Black Rice (Oryza sativa L.) in the Control of Hypercholesterolemia in Rats

Cardiovascular disease is a serious public health problem; it is the first cause of death in Brazil and in developed countries. Thus, it is essential to search for alternative sources such as some functional foods to prevent and control the risks of this disease. The purpose of this study was to evaluate the lipidemic parameters in hypercholesterolemic rats fed diets containing black rice variety IAC 600 or unrefined rice. Adult male Wistar rats (Rattus norvegicus var. albinos) were used, weighing about 200-220 g. The animals were divided into four groups: the first received a control casein diet, the second received hypercholesterolemic diet, and the other two groups, after induction of hypercholesterolemia, received the test diets, the first containing 20% black rice and the second 20% unrefined, for 30 days. It was observed that diet containing black rice reduced the level of plasma cholesterol, triglycerides, and low-density lipoprotein. For high-density lipoprotein values, the diet that provided an increase in the levels was the black rice. The diet containing black rice was more effective in controlling the lipidemia in rats compared with the whole rice diet.

Environmental isolation of black yeast-like fungi involved in human infection

The present study focuses on potential agents of chromoblastomycosis and other endemic diseases in the state of Parana, Southern Brazil. Using a highly selective protocol for chaetothyrialean black yeasts and relatives, environmental samples from the living area of symptomatic patients were analysed. Additional strains were isolated from creosote-treated wood and hydrocarbon-polluted environments, as such polluted sites have been supposed to enhance black yeast prevalence. Isolates showed morphologies compatible with the traditional etiological agents of chromoblastomycosis, e.g. Fonsecaea pedrosoi and Phialophora verrucosa, and of agents of subcutaneous or systemic infections like Cladophialophora bantiana and Exophiala jeanselmei. Some agents of mild disease were indeed encountered. However, molecular analysis proved that most environmental strains differed from known etiologic agents of pronounced disease syndromes: they belonged to the same order, but mostly were undescribed species. Agents of chromoblastomycosis and systemic disease thus far are prevalent on the human host. The hydrocarbon-polluted environments yielded yet another spectrum of chaetothyrialean fungi. These observations are of great relevance because they allow us to distinguish between categories of opportunists, indicating possible differences in pathogenicity and virulence.

Sudan Black B treatment reduces autofluorescence and improves resolution of in situ hybridization specific fluorescent signals of brain sections

Interference by autofluorescence is one of the major concerns of immunofluorescence analysis of in situ hybridization-based diagnostic assays. We present a useful technique that reduces autofluorescent background without affecting the tissue integrity or direct immunofluorescence signals in brain sections. Using six different protocols, such as ammonia/ethanol, Sudan Black B (SBB) in 70% ethanol, photobleaching with UV light and different combinations of them in both formalin-fixed paraffin-embedded and frozen human brain tissue sections, we have found that tissue treatment of SBB in a concentration of 0.1% in 70% ethanol is the best approach to reduce/eliminate tissue autofluorescence and background, while preserving the specific fluorescence hybridization signals. This strategy is a feasible, non-time consuming method that provides a reasonable compromise between total reduction of the tissue autofluorescence and maintenance of specific fluorescent labels.

Perturbations of black p-branes

We consider black p-brane solutions of the low-energy string action, computing scalar perturbations. Using standard methods, we derive the wave equations obeyed by the perturbations and treat them analytically and numerically. We have found that tensorial perturbations obtained via a gauge-invariant formalism leads to the same results as scalar perturbations. No instability has been found. Asymptotically, these solutions typically reduce to a AdSd((p+2)) x Sd((8-p)) space which, in the framework of Maldacena's conjecture, can be regarded as a gravitational dual to a conformal field theory defined in a (p+1)-dimensional flat space-time. The results presented open the possibility of a better understanding the AdS/CFT correspondence, as originally formulated in terms of the relation among brane structures and gauge theories.

Long life of Gauss-Bonnet corrected black holes

Dictated by the string theory and various higher dimensional scenarios, black holes in D > 4-dimensional space-times must have higher curvature corrections. The first and dominant term is quadratic in curvature, and called the Gauss-Bonnet (GB) term. We shall show that although the Gauss-Bonnet correction changes black hole's geometry only softly, the emission of gravitons is suppressed by many orders even at quite small values of the GB coupling. The huge suppression of the graviton emission is due to the multiplication of the two effects: the quick cooling of the black hole when one turns on the GB coupling and the exponential decreasing of the gray-body factor of the tensor type of gravitons at small and moderate energies. At higher D the tensor gravitons emission is dominant, so that the overall lifetime of black holes with Gauss-Bonnet corrections is many orders larger than was expected. This effect should be relevant for the future experiments at the Large Hadron Collider (LHC).